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Sample records for a508 gr 4n

  1. Master curve characterization of the fracture toughness behavior in SA508 Gr.4N low alloy steels

    NASA Astrophysics Data System (ADS)

    Lee, Ki-Hyoung; Kim, Min-Chul; Lee, Bong-Sang; Wee, Dang-Moon

    2010-08-01

    The fracture toughness properties of the tempered martensitic SA508 Gr.4N Ni-Mo-Cr low alloy steel for reactor pressure vessels were investigated by using the master curve concept. These results were compared to those of the bainitic SA508 Gr.3 Mn-Mo-Ni low alloy steel, which is a commercial RPV material. The fracture toughness tests were conducted by 3-point bending with pre-cracked charpy (PCVN) specimens according to the ASTM E1921-09c standard method. The temperature dependency of the fracture toughness was steeper than those predicted by the standard master curve, while the bainitic SA508 Gr.3 steel fitted well with the standard prediction. In order to properly evaluate the fracture toughness of the Gr.4N steels, the exponential coefficient of the master curve equation was changed and the modified curve was applied to the fracture toughness test results of model alloys that have various chemical compositions. It was found that the modified curve provided a better description for the overall fracture toughness behavior and adequate T0 determination for the tempered martensitic SA508 Gr.4N steels.

  2. Creep of A508/533 Pressure Vessel Steel

    SciTech Connect

    Richard Wright

    2014-08-01

    ABSTRACT Evaluation of potential Reactor Pressure Vessel (RPV) steels has been carried out as part of the pre-conceptual Very High Temperature Reactor (VHTR) design studies. These design studies have generally focused on American Society of Mechanical Engineers (ASME) Code status of the steels, temperature limits, and allowable stresses. Initially, three candidate materials were identified by this process: conventional light water reactor (LWR) RPV steels A508 and A533, 2¼Cr-1Mo in the annealed condition, and Grade 91 steel. The low strength of 2¼Cr-1Mo at elevated temperature has eliminated this steel from serious consideration as the VHTR RPV candidate material. Discussions with the very few vendors that can potentially produce large forgings for nuclear pressure vessels indicate a strong preference for conventional LWR steels. This preference is based in part on extensive experience with forging these steels for nuclear components. It is also based on the inability to cast large ingots of the Grade 91 steel due to segregation during ingot solidification, thus restricting the possible mass of forging components and increasing the amount of welding required for completion of the RPV. Grade 91 steel is also prone to weld cracking and must be post-weld heat treated to ensure adequate high-temperature strength. There are also questions about the ability to produce, and very importantly, verify the through thickness properties of thick sections of Grade 91 material. The availability of large components, ease of fabrication, and nuclear service experience with the A508 and A533 steels strongly favor their use in the RPV for the VHTR. Lowering the gas outlet temperature for the VHTR to 750°C from 950 to 1000°C, proposed in early concept studies, further strengthens the justification for this material selection. This steel is allowed in the ASME Boiler and Pressure Vessel Code for nuclear service up to 371°C (700°F); certain excursions above that temperature are

  3. GR uniqueness and deformations

    NASA Astrophysics Data System (ADS)

    Krasnov, Kirill

    2015-10-01

    In the metric formulation gravitons are described with the parity symmetric S + 2 ⊗ S - 2 representation of Lorentz group. General Relativity is then the unique theory of interacting gravitons with second order field equations. We show that if a chiral S + 3 ⊗ S - representation is used instead, the uniqueness is lost, and there is an infinite-parametric family of theories of interacting gravitons with second order field equations. We use the language of graviton scattering amplitudes, and show how the uniqueness of GR is avoided using simple dimensional analysis. The resulting distinct from GR gravity theories are all parity asymmetric, but share the GR MHV amplitudes. They have new all same helicity graviton scattering amplitudes at every graviton order. The amplitudes with at least one graviton of opposite helicity continue to be determinable by the BCFW recursion.

  4. Processing and properties of superclean ASTM A508 Cl. 4 forgings

    SciTech Connect

    Hinkel, A.V.; Handerhan, K.J.; Manzo, G.J.; Simkins, G.P.

    1988-12-31

    Steels with improved resistance to temper embrittlement are now being produced using ``superclean`` steelmaking technology. This technology involves the use of scrap control, proper electric arc furnace and ladle refining furnace practices to produce steel with very low Mn, Si, P, S and other residual impurities such as Sn, As and Sb. This technology has been applied on a production basis to modified ASTM A508 Cl- 4 material intended for high temperature pressure vessel forgings. Processing and properties of this superclean material are reviewed. In addition, the cleanliness and mechanical properties are compared to conventionally melted A508 Cl. 4 material. The ``superclean`` A508 Cl. 4 mod. was found to meet all specification requirements. In addition, the superclean material was found to possess superior upper shelf CVN properties, a lower FATT{sub 50} and NDTT, along with superior microcleanliness compared to conventional material. Finally, the superclean material was found to be immune to temper embrittlement based on the short-term embrittlement treatments examined.

  5. Results of crack-arrest tests on irradiated a 508 class 3 steel

    SciTech Connect

    Iskander, S.K.; Milella, P.P.; Pini, M.A.

    1998-02-01

    Ten crack-arrest toughness values for irradiated specimens of A 508 class 3 forging steel have been obtained. The tests were performed according to the American Society for Testing and Materials (ASTM) Standard Test Method for Determining Plane-Strain Crack-Arrest Fracture Toughness, K{sub la} of Ferritic Steels, E 1221-88. None of these values are strictly valid in all five ASTM E 1221-88 validity criteria. However, they are useful when compared to unirradiated crack-arrest specimen toughness values since they show the small (averaging approximately 10{degrees}C) shifts in the mean and lower-bound crack-arrest toughness curves. This confirms that a low copper content in ASTM A 508 class 3 forging material can be expected to result in small shifts of the transition toughness curve. The shifts due to neutron irradiation of the lower bound and mean toughness curves are approximately the same as the Charpy V-notch (CVN) 41-J temperature shift. The nine crack-arrest specimens were irradiated at temperatures varying from 243 to 280{degrees}C, and to a fluence varying from 1.7 to 2.7 x 10{sup 19} neutrons/cm{sup 2} (> 1 MeV). The test results were normalized to reference values that correspond to those of CVN specimens irradiated at 284{degrees}C to a fluence of 3.2 x 10{sup 19} neutrons/cm{sup 2} (> 1 MeV) in the same capsule as the crack-arrest specimens. This adjustment resulted in a shift to lower temperatures of all the data, and in particular moved two data points that appeared to lie close to or lower than the American Society of Mechanical Engineers K{sub la} curve to positions that seemed more reasonable with respect to the remaining data. A special fixture was designed, fabricated, and successfully used in the testing. For reasons explained in the text, special blocks to receive the Oak Ridge National Laboratory clip gage were designed, and greater-than-standard crack-mouth opening displacements measured were accounted for. 24 refs., 13 figs., 12 tabs.

  6. Creep rupture testing of alloy 617 and A508/533 base metals and weldments.

    SciTech Connect

    Natesan, K.; Li, M.; Soppet, W.K.; Rink, D.L.

    2012-01-17

    The NGNP, which is an advanced HTGR concept with emphasis on both electricity and hydrogen production, involves helium as the coolant and a closed-cycle gas turbine for power generation with a core outlet/gas turbine inlet temperature of 750-1000 C. Alloy 617 is a prime candidate for VHTR structural components such as reactor internals, piping, and heat exchangers in view of its resistance to oxidation and elevated temperature strength. However, lack of adequate data on the performance of the alloy in welded condition prompted to initiate a creep test program at Argonne National Laboratory. In addition, Testing has been initiated to evaluate the creep rupture properties of the pressure vessel steel A508/533 in air and in helium environments. The program, which began in December 2009, was certified for quality assurance NQA-1 requirements during January and February 2010. Specimens were designed and fabricated during March and the tests were initiated in April 2010. During the past year, several creep tests were conducted in air on Alloy 617 base metal and weldment specimens at temperatures of 750, 850, and 950 C. Idaho National Laboratory, using gas tungsten arc welding method with Alloy 617 weld wire, fabricated the weldment specimens. Eight tests were conducted on Alloy 617 base metal specimens and nine were on Alloy 617 weldments. The creep rupture times for the base alloy and weldment tests were up to {approx}3900 and {approx}4500 h, respectively. The results showed that the creep rupture lives of weld specimens are much longer than those for the base alloy, when tested under identical test conditions. The test results also showed that the creep strain at fracture is in the range of 7-18% for weldment samples and were much lower than those for the base alloy, under similar test conditions. In general, the weldment specimens showed more of a flat or constant creep rate region than the base metal specimens. The base alloy and the weldment exhibited tertiary creep

  7. Glucocorticoid receptor (GR) {beta} has intrinsic, GR{alpha}-independent transcriptional activity

    SciTech Connect

    Kino, Tomoshige; Manoli, Irini; Kelkar, Sujata; Wang, Yonghong; Su, Yan A.; Chrousos, George P.

    2009-04-17

    The human glucocorticoid receptor (GR) gene produces C-terminal GR{beta} and GR{alpha} isoforms through alternative use of specific exons 9{beta} and {alpha}, respectively. We explored the transcriptional activity of GR{beta} on endogenous genes by developing HeLa cells stably expressing EGFP-GR{beta} or EGFP. Microarray analyses revealed that GR{beta} had intrinsic gene-specific transcriptional activity, regulating mRNA expression of a large number of genes negatively or positively. Majority of GR{beta}-responsive genes was distinct from those modulated by GR{alpha}, while GR{beta} and GR{alpha} mutually modulated each other's transcriptional activity in a subpopulation of genes. We did not observe in HCT116 cells nuclear translocation of GR{beta} and activation of this receptor by RU 486, a synthetic steroid previously reported to bind GR{beta} and to induce nuclear translocation. Our results indicate that GR{beta} has intrinsic, GR{alpha}-independent, gene-specific transcriptional activity, in addition to its previously reported dominant negative effect on GR{alpha}-induced transactivation of GRE-driven promoters.

  8. Synthesis of bicyclo[4.n.1]alkanones.

    PubMed

    Montalt, Joaquin; Linker, Frédéric; Ratel, Frédéric; Miesch, Michel

    2004-10-01

    Cyclic beta-keto ester monoanions react with 1,4-dihalobutenes to give C-alkylated products which subsequently undergo a stereoselective SN2' O-alkylation reaction to yield functionalized enol ethers. When the starting material was ethyl cyclopentanone carboxylate, the C-alkylated product, treated with a base, directly afforded the functionalized bicyclo[4.2.1]nonanone. The enol ethers were submitted to a flash vacuum thermolysis (FVT) reaction to readily afford functionalized bicyclo[4.n.1]alkanones (n = 3, 4). This reaction sequence was applied to the synthesis of a functionalized tricyclo[7.4.1.0(1,5)]tetradecanone, which represents an analogue to the tricyclic core of ingenol. PMID:15387595

  9. Narrow groove gas tungsten arc welding of ASTM A508 Class 4 steel for improved toughness properties

    SciTech Connect

    Penik, M.A. Jr.

    1997-04-01

    Welding of heavy section steel has traditionally used the automatic submerged arc welding (ASAW) process because of the high deposition rates achievable. However, the properties, particularly fracture toughness, of the weld are often inferior when compared to base material. This project evaluated the use of narrow groove gas tungsten arc welding (GTAW) to improve weld material properties. The welding procedures were developed for ASTM A508 Class 4 base material using a 1% Ni filler material complying to AWS Specification A.23-90-EF3-F3-N. A narrow groove joint preparation was used in conjunction with the GTAW process so competitive fabrication rates could be achieved when compared to the ASAW process. Weld procedures were developed to refine weld substructure to achieve better mechanical properties. Two heaters of weld wire were used to examine the effects of minor filler metal chemistry differences on weld mechanical properties. Extensive metallographic evaluations showed excellent weld quality with a refined microstructure. Chemical analysis of the weld metal showed minimal weld dilution by the base metal. Mechanical testing included bend and tensile tests to ensure weld quality and strength. A Charpy impact energy curve versus temperature and fracture toughness curve versus temperature were developed for each weld wire heat. Results of fracture toughness and Charpy impact testing indicated an improved transition temperature closer to that of the base material properties.

  10. An evaluation of the stability of synthetic groundwater formulations GR-3 and GR-4

    SciTech Connect

    Dill, J.A.; Jones, T.E.; Marcy, A.D.; Baechler, M.O.; Payne, J.R.

    1984-10-08

    Simple solubility calculations indicate that synthetic groundwater formulations GR-3 and GR-4 may be unstable with respect to the precipitation of certain components. However, the validity of calculations of this type is limited by the complexity of these solutions. In order to properly address the chemical stability of these formulations, an experimental evaluation has been accomplished. The findings were that GR-3 and GR-4 were similar in their chemical stability. Both were found to be quite stable with respect to all constituents except silicate and inorganic carbon over a 30-day period. Some instability of monomeric silicate was observed. However, this did not result in a concentration change of greater than 5%, and no evidence of particulate formation was observed. 6 refs., 30 tabs.

  11. Genetic characterization of avian influenza subtype H4N6 and H4N9 from live bird market, Thailand

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A one year active surveillance program for influenza A viruses among avian species in a live-bird market (LBM) in Bangkok, Thailand was conducted in 2009. Out of 970 samples collected, influenza A virus subtypes H4N6 (n=2) and H4N9 (n=1), were isolated from healthy Muscovy ducks. All three viruses w...

  12. Deformations of GR and BH thermodynamics

    NASA Astrophysics Data System (ADS)

    Krasnov, Kirill

    2016-08-01

    In four space-time dimensions General Relativity can be non-trivially deformed. Deformed theories continue to describe two propagating degrees of freedom, as GR. We study Euclidean black hole thermodynamics of these deformations. We use the recently developed formulation that works with {{SO}}(3) connections as well as certain matrices M of auxiliary fields. We show that the black hole entropy is given by one quarter of the horizon area as measured by the Lie algebra valued two-form MF, where F is the connection curvature. This coincides with the horizon area as measured by the metric only for the case of General Relativity.

  13. Deformations of GR and BH thermodynamics

    NASA Astrophysics Data System (ADS)

    Krasnov, Kirill

    2016-08-01

    In four space–time dimensions General Relativity can be non-trivially deformed. Deformed theories continue to describe two propagating degrees of freedom, as GR. We study Euclidean black hole thermodynamics of these deformations. We use the recently developed formulation that works with {{SO}}(3) connections as well as certain matrices M of auxiliary fields. We show that the black hole entropy is given by one quarter of the horizon area as measured by the Lie algebra valued two-form MF, where F is the connection curvature. This coincides with the horizon area as measured by the metric only for the case of General Relativity.

  14. An evaluation of the stability of synthetic Grande Ronde groundwater formulations GR-3 and GR-4

    SciTech Connect

    Dill, J.A.; Jones, T.E.; Marcy, A.D.; Baechler, M.O.; Payne, J.R.

    1987-03-01

    Simple solubility calculations indicate that synthetic Grande Ronde groundwater formulations GR-3 and GR-4 may be unstable with respect to the precipitation of certain components. The validity of calculations of this type is, however, limited by the complexity of the solutions. To address the chemical stability of these formulations properly, an experimental evaluation was performed. The evaluation revealed that GR-3 and GR-4 were similar in their chemical stability. Both were found to be quite stable with respect to all constituents, except silicate and inorganic carbon, over a 30-d period. Some instability of monomeric silicate was observed. However, this did not result in a concentration change of greater than 5%, and no evidence of particulate formation was observed. Both formulations were found to be relatively unstable with respect to inorganic carbon concentration. A general trend toward increasing carbon concentration was observed. This was attributed to absorption of CO/sub 2/ from the atmosphere. Storing the synthetic groundwater in sealed containers eliminated this problem. 5 refs., 24 tabs.

  15. Over-Contact Binary GR Tauri

    NASA Astrophysics Data System (ADS)

    Snyder, Lee

    2009-05-01

    New times of minima and ephemeredes are presented on the over-contact system GR Tauri. An observed minus calculated (O-C), times of minimum chart was constructed and based on statistical analysis the orbital period of the system is found to be decreasing with a rate of dP/dE = 3.33^-4 seconds Yr^-1 since 1931. Both components are filling their respective critical Roche lobes with fillouts f = 0.11 and 0.95. The light curve displays the O'Connell effect which is discussed on the assumption mass is going from the primary to the secondary creating a hot spot. The TRO, thermal relaxation oscillations (Lucy & Wilson 1979), theory is discussed as an explanation.

  16. [Mechanism of NH(4+)-N removal in drinking water biofilter].

    PubMed

    Liu, Bing; Fan, Hui; Yu, Guo-Zhong; Yu, Xin; Zhao, Cheng-Mei; Li, Qing-Fei; Zhang, Shu-Ting; Wei, Bo

    2012-07-01

    In order to explore the mechanism of NH(4+)-N removal in drinking water biofilter, water quality parameters, such as NH(4+)-N, NO(2-)-N, NO(3-)-N, total phosphorus, permanganate index, nitrogen gas, temperature and dissolved oxygen etc, were determined in the inflow and outflow of biofilter. Samples of granular activated carbon (GAC) at different height (0, 10, 20, 40, 60 cm) of the biofiter media were collected and analyzed for the bacterial community with molecular biology techniques. The bacterial diversity in the activated carbon biofilm sample was studied based on the phylogenetic analysis of sequences. The results showed that there were three stages according to the NH(4+)-N concentration in the influent. The "nitrogen loss" phenomenon (total inorganic nitrogen in the effluent was less than that in the influent) occurred at the first, second and third stages and the amount of nitrogen loss were 0.94, 0.32 and 0.15 mg x L(-1), respectively. The amount of nitrogen loss had a good positive correlation with the NH(4+)-N concentration in the influent, but not a linear relationship with the concentration of the permanganate index in the influent. The average concentrations of N2 increased gradually with the height of media in the biofilter, with values of 14.04 and 14.67 mg x L(-1) in the influent and the effluent, respectively. Based on the sequencing results, the ammonia-oxidizing bacteria (AOB) in the activated carbon biofilm were classified into three common genera: Nitrosococcus, Nitrosomonas and Nitrosospira. When the NH(4+)-N concentration in the influent was relatively high, the "nitrogen loss" phenomenon in biofilter was caused by the AOB.

  17. Potential for 4-n-nonylphenol biodegradation in stream sediments

    USGS Publications Warehouse

    Bradley, P.M.; Barber, L.B.; Kolpin, D.W.; McMahon, P.B.; Chapelle, F.H.

    2008-01-01

    The potential for in situ biodegradation of 4-nonylphenol (4-NP) was investigated in three hydrologically distinct streams impacted by wastewater treatment plants (WWTPs) in the United States. Microcosms were prepared with sediments from each site and amended with [U-ring-14C]4-n-nonylphenol (4-n-NP) as a model test substrate. Microcosms prepared with sediment collected upstream of the WWTP outfalls and incubated under oxic conditions showed rapid and complete mineralization of [U-ring-14C]4- n-NP to 14CO2 in all three systems. In contrast, no mineralization of [U-ring-14C]4-n-NP was observed in these sediments under anoxic (methanogenic) conditions. The initial linear rate of [U-ring-14C]4-n-NP mineralization in sediments from upstream and downstream of the respective WWTP outfalls was inversely correlated with the biochemical oxygen demand (BOD) of the streambed sediments. These results suggest that the net supply of dissolved oxygen to streambed sediments is a key determinant of the rate and extent of 4-NP biodegradation in stream systems. In the stream systems considered by the present study, dissolved oxygen concentrations in the overlying water column (8–10 mg/L) and in the bed sediment pore water (1–3 mg/L at a depth of 10 cm below the sediment–water interface) were consistent with active in situ 4-NP biodegradation. These results suggest WWTP procedures that maximize the delivery of dissolved oxygen while minimizing the release of BOD to stream receptors favor efficient biodegradation of 4-NP contaminants in wastewater-impacted stream environments.

  18. The role of glucocorticoid receptor (GR) polymorphisms in human erythropoiesis

    PubMed Central

    Varricchio, Lilian; Migliaccio, Anna Rita

    2014-01-01

    Glucocorticoids are endogenous steroid hormones that regulate several biological functions including proliferation, differentiation and apoptosis in numerous cell types in response to stress. Synthetic glucocorticoids, such as dexamethasone (Dex) are used to treat a variety of diseases ranging from allergy to depression. Glucocorticoids exert their effects by passively entering into cells and binding to a specific Glucocorticoid Receptor (GR) present in the cytoplasm. Once activated by its ligand, GR may elicit cytoplasmic (mainly suppression of p53), and nuclear (regulation of transcription of GR responsive genes), responses. Human GR is highly polymorphic and may encode > 260 different isoforms. This polymorphism is emerging as the leading cause for the variability of phenotype and response to glucocorticoid therapy observed in human populations. Studies in mice and clinical observations indicate that GR controls also the response to erythroid stress. This knowledge has been exploited in-vivo by using synthetic GR agonists for treatment of the erythropoietin-refractory congenic Diamond Blackfan Anemia and in-vitro to develop culture conditions that may theoretically generate red cells in numbers sufficient for transfusion. However, the effect exerted by GR polymorphism on the variability of the phenotype of genetic and acquired erythroid disorders observed in the human population is still poorly appreciated. This review will summarize current knowledge on the biological activity of GR and of its polymorphism in non-hematopoietic diseases and discuss the implications of these observations for erythropoiesis. PMID:25755906

  19. Degradation of 4-n-nonylphenol under nitrate reducing conditions

    PubMed Central

    Viñas, Marc; Grotenhuis, Tim; Rijnaarts, Huub H. M.; Langenhoff, Alette A. M.

    2010-01-01

    Nonylphenol (NP) is an endocrine disruptor present as a pollutant in river sediment. Biodegradation of NP can reduce its toxicological risk. As sediments are mainly anaerobic, degradation of linear (4-n-NP) and branched nonylphenol (tNP) was studied under methanogenic, sulphate reducing and denitrifying conditions in NP polluted river sediment. Anaerobic bioconversion was observed only for linear NP under denitrifying conditions. The microbial population involved herein was further studied by enrichment and molecular characterization. The largest change in diversity was observed between the enrichments of the third and fourth generation, and further enrichment did not affect the diversity. This implies that different microorganisms are involved in the degradation of 4-n-NP in the sediment. The major degrading bacteria were most closely related to denitrifying hexadecane degraders and linear alkyl benzene sulphonate (LAS) degraders. The molecular structures of alkanes and LAS are similar to the linear chain of 4-n-NP, this might indicate that the biodegradation of linear NP under denitrifying conditions starts at the nonyl chain. Initiation of anaerobic NP degradation was further tested using phenol as a structure analogue. Phenol was chosen instead of an aliphatic analogue, because phenol is the common structure present in all NP isomers while the structure of the aliphatic chain differs per isomer. Phenol was degraded in all cases, but did not affect the linear NP degradation under denitrifying conditions and did not initiate the degradation of tNP and linear NP under the other tested conditions. PMID:20640878

  20. The effects of temperature and aeration on the corrosion of A508III low alloy steel in boric acid solutions at 25-95 °C

    NASA Astrophysics Data System (ADS)

    Xiao, Qian; Lu, Zhanpeng; Chen, Junjie; Yao, Meiyi; Chen, Zhen; Ejaz, Ahsan

    2016-11-01

    The effects of temperature, solution composition and dissolved oxygen on the corrosion rate and electrochemical behavior of an A508III low alloy steel in boric acid solution with lithium hydroxide at 25-95 °C are investigated. In aerated solutions, increasing the boric acid concentration increases the corrosion rate and the anodic current density. The corrosion rate in deaerated solutions increases with increasing temperature. A corrosion rate peak value is found at approximately 75 °C in aerated solutions. Increasing temperature increases the oxygen diffusion coefficient, decreases the dissolved oxygen concentration, accelerates the hydrogen evolution reaction, and accelerates both the active dissolution and the film forming reactions. Increasing dissolved oxygen concentration does not significantly affect the corrosion rate at 50 and 60 °C, increases the corrosion rate at 70 and 80 °C, and decreases the corrosion rate at 87.5 and 95 °C in a high concentration boric acid solution with lithium hydroxide.

  1. Computing Gröbner Bases within Linear Algebra

    NASA Astrophysics Data System (ADS)

    Suzuki, Akira

    In this paper, we present an alternative algorithm to compute Gröbner bases, which is based on computations on sparse linear algebra. Both of S-polynomial computations and monomial reductions are computed in linear algebra simultaneously in this algorithm. So it can be implemented to any computational system which can handle linear algebra. For a given ideal in a polynomial ring, it calculates a Gröbner basis along with the corresponding term order appropriately.

  2. Spectroscopic confirmation of the dwarf nova nature of GR Orionis

    NASA Astrophysics Data System (ADS)

    Arai, Akira; Nogami, Daisaku

    2013-02-01

    We spectroscopically observed GR Ori with the 2.0-m Nayuta Telescope at Nishi-Harima Astronomical Observatory on 2013 February 13. This observation was carried out with the low resolution mode (R~1,000) of the optical spectrograph MALLS which covers the wavelength of 4,000-6,800 A. GR Ori was discovered as a possible nova in 1916 (Thiele 1916, Astron. Nachr., 202, 213), but has long been suspected to be a dwarf nova (e.g.

  3. Regioselective and stereospecific hydroxylation of GR24 by Sorghum bicolor and evaluation of germination inducing activities of hydroxylated GR24 stereoisomers toward seeds of Striga species.

    PubMed

    Ueno, Kotomi; Ishiwa, Shunsuke; Nakashima, Hitomi; Mizutani, Masaharu; Takikawa, Hirosato; Sugimoto, Yukihiro

    2015-09-15

    Bioconversion of GR24, the most widely used synthetic strigolactone (SL), by hydroponically grown sorghum (Sorghum bicolor) and biological activities of hydroxylated GR24 stereoisomers were studied. Analysis of extracts and exudates of sorghum roots previously fed with a racemic and diastereomeric mixture of GR24, using liquid chromatography-tandem mass spectrometry with multiple reaction monitoring (MRM), confirmed uptake of GR24 and suggested its conversion to mono-hydroxylated products. Two major GR24 metabolites, 7-hydroxy-GR24 and 8-hydroxy-GR24, were identified in the root extracts and exudates by direct comparison of chromatographic behavior with a series of synthetic mono-hydroxylated GR24 analogues. Separate feeding experiments with each of the GR24 stereoisomers revealed that the hydroxylated products were derived from 2'-epi-GR24, an evidence of sterical recognition of the GR24 molecule by sorghum. Trans-4-hydroxy-GR24 isomers derived from all GR24 stereoisomers were detected in the exudates as minor metabolites. The synthetic hydroxy-GR24 isomers induced germination of Striga hermonthica in decreasing order of C-8>C-7>C-6>C-5>C-4. In contrast the stereoisomers having the same configuration of orobanchol, irrespective of position of hydroxylation, induced germination of Striga gesnerioides. The results confirm previous reports on structural requirements of SLs and ascribe a critical role to hydroxylation, but not to the position of the hydroxyl group in the AB part of the molecule, in induction of S. gesnerioides seed germination.

  4. Computational chemical studies on thermochemistry and ring strains in cyclic [n]metaphenyleneacetylenes, butadiyne-bridged [4n]metacyclophynes, and butadiyne-bridged [4n]paracyclophynes.

    PubMed

    Ali, Mohamad Akbar; Krishnan, Mangala Sunder

    2010-09-01

    The thermochemical properties and ring strains in cyclic [n]metaphenyleneacetylenes ([n]CMPAs), butadiyne-bridged [4(n)]metacyclophynes (B-B[4(n)]MCs), and butadiyne-bridged [4(n)]paracyclophynes (B-B[4(n)]PCs) were studied using a homodesmotic reaction scheme coupled with density functional theory (B3LYP/6-31G*, mPW1PW91/6-31G*, and M06-2X/6-31+G**//B3LYP/6-31G*). Strain energies of [n]CMPAs and B-B[4(n)]MCs decrease first from very high values for small rings to become zero when n becomes 6, then increase with n, and finally decrease as n becomes larger than 8. In the case of B-B[4(n)]PCs, strain energies decrease with increasing n. Heats of formation of [n]CMPAs, B-B[4(n)]MCs, and B-B[4(n)]PCs increase steadily with increasing numbers of phenylacetylene and 1-(buta-1,3-diynyl)benzene to reach a near-constant value per unit monomer as n increases. The geometries and (vibrational and nuclear magnetic resonance) spectroscopic properties of [n]CMPAs, B-B[4(n)]MCs, and B-B[4(n)]PCs were also studied. Geometrical parameters, Raman frequencies, and (1)H NMR chemical shifts of [3]CMPA and [4]CMPA are found to be in good agreement with compounds for which there are experimentally available values at the B3LYP/6-31G* level of theory. In addition, electronic structure calculations were carried out for [n]CMPAs, B-B[4(n)]MCs, and B-B[4(n)]PCs. Ring diameters were also calculated for B-B[4(n)]PCs. PMID:20695635

  5. Variable stars in the dwarf galaxy GR 8 (DDO 155)

    NASA Technical Reports Server (NTRS)

    Tolstoy, Eline; Saha, A.; Hoessel, John G.; Danielson, G. Edward

    1995-01-01

    Observations of the resolved stars in dwarf galaxy GR 8, obtained over the period 1980 February to 1994 March, are presented. Thirty-four separate epochs were searched for variable stars, and a total of six were found, of which one has Cepheid characteristics. After correction for Galactic extinction this single Cepheid yields a distance modulus of m - M = 26.75 +/- 0.35. This corresponds to a distance of 2.24 Mpc, placing GR 8 near the Local Group (LG) zero-velocity surface. The other five variable stars are very red, and possibly have long periods of order 100 days or more.

  6. Alpha-plutonium's Grüneisen parameter

    NASA Astrophysics Data System (ADS)

    Ledbetter, Hassel; Lawson, Andrew; Migliori, Albert

    2010-04-01

    Reported Grüneisen parameters γ of alpha-plutonium range from 3.0 to 9.6, which is remarkable because typical Grüneisen parameter uncertainty seldom exceeds ± 0.5. Our six new estimates obtained by different methods range from 3.2 to 9.6. The new estimates arise from Grüneisen's rule, from Einstein model and Debye model fits to low-temperature ΔV/V, from the bulk modulus temperature dependence, from the zero-point-energy contribution to the bulk modulus, and from another Grüneisen relationship whereby γ is estimated from only the bulk modulus and volume changes with temperature (or pressure). We disregard several high estimates because of the itinerant-localized 5f-electron changes during temperature changes and pressure changes. Considering all these estimates, for alpha-plutonium, we recommend γ = 3.7 ± 0.4, slightly high compared with values for all elemental metals.

  7. Preparation of Polyclonal Antibody and Expression Analysis of GR in Tomato

    NASA Astrophysics Data System (ADS)

    Xie, Yuanhong; Zhu, Benzhong; Luo, Yunbo; Chen, Xiangning; Zhang, Hongxing

    The fruit ripening of Green-ripe (Gr) mutant tomato was inhibited dramatically. To determine the expression patterns of Gr in tomato, we first produced the polyclonal antibody of Gr protein. RT-PCR was used to amplify the Gr gene from green ripe tomato fruit. And the PCR product was subcloned into prokaryotic protein expression vectors pET-30a to generate recombinant plasmid. The Gr protein was induced by IPTG in BL21 (DE3) and purified by Ni-NTA agarose column. The anti-Gr serum was produced by immunizing rabbits, and the titer of the anti-Gr serum was above 5000 by ELISA analysis. Purified by the DEAE-52 ion-column, the high purification level of anti-Gr polyclonal antibody was obtained. Furthermore, RT-CPR was used in the RNA level to demonstrate that the expression of Gr gene was specialized in some cultures of tomato. For example, the expressions of Gr were higher in seed, flower and green ripe fruit than others, and the expression level were reduced by exogenous ethylene treatment in the flower and green ripe fruit. Moreover, Polyclonal antibody of Gr was used to investigate the expression pattern of Gr in protein level by the Western blotting. Our results show that the expression level of Gr in protein level was complied with the expressions in RNA. So, we suggested that the regulation of Gr was transcriptional.

  8. The Carbon Abundance in Thesuper Metal Poorgalaxy GR 8

    NASA Astrophysics Data System (ADS)

    Dufour, Reginald J.

    We propose to obtain three 16+ hour SWP low dispersion spectra of the brightest H II region in the nearby metal-poor dwarf irregular galaxy GR 8 via combined ESA/SERC + US shifts. The primary objective is to measure the C III]A909 emission line for determination of the gaseousphase carbon abundance in this galaxy, for which O/H is only 3% of solar. GR 8 is one of only a very few galaxies known to have O/H at 2-3% of solar; that is, comparable to I Zw 18, for which recent IUE and ground-based observations have found surprisingly high CIO and N/O values. The unexpectedly high C/O found in I Zw 18 for its O/H value is counter to the trend of C/O proportional to O/H found in several metal-poor irregulars with giant H II regions previously studied with the IUE, and thus observations of GR 8 would be fundamental to evaluating the reversed C/O trend at lowest O/H indicated by I Zw 18. In addition, the UV stellar continuum of GR 8 from the SWP spectra will provide information about the comparative high mass IMF and recent star formation history of GR 8 compared to I Zw 18. This should effectively double our knowledge regarding the UV spectra of H II regions and OB stars in chemically young star-forming galaxies at the low luminosity and metallicity limits for such galaxies.

  9. Grid Analysis and Display System (GrADS): A practical tool for earth science visualization

    NASA Technical Reports Server (NTRS)

    Kinter, James L., III; Doty, Brian E.

    1991-01-01

    Viewgraphs on grid analysis and display system (GrADS): a practical tool for earth science visualization are presented. Topics covered include: GrADS design goals; data sets; and temperature profiles.

  10. Iceland's Grímsvötn volcano erupts

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2011-05-01

    About 13 months after Iceland's Eyjafjallajökull volcano began erupting on 14 April 2010, which led to extensive air traffic closures over Europe, Grímsvötn volcano in southeastern took its turn. Iceland's most active volcano, which last erupted in 2004 and lies largely beneath the Vatnajökull ice cap, began its eruption activity on 21 May, with the ash plume initially reaching about 20 kilometers in altitude, according to the Icelandic Meteorological Office. Volcanic ash from Grímsvötn has cancelled hundreds of airplane flights and prompted U.S. president Barack Obama to cut short his visit to Ireland. As Eos went to press, activity at the volcano was beginning to subside.

  11. Is there a mildly relativistic jet in SN2007gr?

    NASA Astrophysics Data System (ADS)

    Paragi, Z.; van der Horst, A. J.; Tanaka, M.; Taylor, G. B.; Kouveliotou, C.; Granot, J.; Ramirez-Ruiz, E.; Pidopryhora, Y.; Bourke, S.; Campbell, R. M.; Garrett, M. A.; van Langevelde, H. J.

    2011-02-01

    SN2007gr was an ordinary type Ic supernova, with a hint of asymmetric explosion seen in the optical polarization spectrum. This type of SNe is occasionally associated with long duration gamma-ray bursts which generate ultra-relativistic jets; no relativistic outflows have yet been found by direct imaging in SNe Ib/c explosions. High resolution very long baseline interferometry (VLBI) data and simultaneous total radio flux density measurements indicated that SN2007gr has expanded mildly relativistically. We performed late time Westerbork Synthesis Radio Telescope (WSRT) observations to measure the level of the underlying extended emission. Comparison of the VLBI and the background-subtracted WSRT and independent VLA data indicate an at least partially resolved source with an average expansion velocity of >=0.4c, although the VLBI data could be consistent with a fainter source with an expansion velocity of ~0.2c as well.

  12. The Grid Analysis and Display System (GrADS)

    NASA Technical Reports Server (NTRS)

    Kinter, James L., III

    1994-01-01

    During the period 1 September 1993 - 31 August 1994, further development of the Grid Analysis and Display System (GrADS) was conducted at the Center for Ocean-Land-Atmosphere Studies (COLA) of the Institute of Global Environment and Society, Inc. (IGES) under subcontract 5555-31 from the University Space Research Association (USRA) administered by The Center of Excellence in Space Data and Information Sciences (CESDIS). This final report documents progress made under this subcontract and provides directions on how to access the software and documentation developed therein. A short description of GrADS is provided followed by summary of progress completed and a summary of the distribution of the software to date and the establishment of research collaborations.

  13. e-VLBI detection of SN2007gr

    NASA Astrophysics Data System (ADS)

    Paragi, Z.; Kouveliotou, C.; Garrett, M. A.; Ramirez-Ruiz, E.; van Langevelde, H. J.; Szomoru, A.; Argo, M.

    2007-09-01

    We observed the Type Ibc SN2007gr on 6-7 September for 12 hours (21:00-09:00 UTC) at 4.97 GHz with the the European VLBI Network (EVN) using the e- VLBI technique. Participating telescopes were Darnhall, Jodrell Bank (MkII), Medicina, Onsala, Torun and Westerbork (phased array of 14 telescopes). The aggregate bitrate was 256 Mbps, except for Darnhall which contributed with an effective data rate of 128 Mbps due to analog bandwidth restrictions.

  14. Gr33a modulates Drosophila male courtship preference.

    PubMed

    Hu, Yujia; Han, Yi; Shao, Yingyao; Wang, Xingjun; Ma, Yeqing; Ling, Erjun; Xue, Lei

    2015-01-01

    In any gamogenetic species, attraction between individuals of the opposite sex promotes reproductive success that guarantees their thriving. Consequently, mate determination between two sexes is effortless for an animal. However, choosing a spouse from numerous attractive partners of the opposite sex needs deliberation. In Drosophila melanogaster, both younger virgin females and older ones are equally liked options to males; nevertheless, when given options, males prefer younger females to older ones. Non-volatile cuticular hydrocarbons, considered as major pheromones in Drosophila, constitute females' sexual attraction that act through males' gustatory receptors (Grs) to elicit male courtship. To date, only a few putative Grs are known to play roles in male courtship. Here we report that loss of Gr33a function or abrogating the activity of Gr33a neurons does not disrupt male-female courtship, but eliminates males' preference for younger mates. Furthermore, ectopic expression of human amyloid precursor protein (APP) in Gr33a neurons abolishes males' preference behavior. Such function of APP is mediated by the transcription factor forkhead box O (dFoxO). These results not only provide mechanistic insights into Drosophila male courtship preference, but also establish a novel Drosophila model for Alzheimer's disease (AD). PMID:25586066

  15. Grüneisen parameter for gases and superfluid helium

    NASA Astrophysics Data System (ADS)

    de Souza, Mariano; Menegasso, Paulo; Paupitz, Ricardo; Seridonio, Antonio; Lagos, Roberto E.

    2016-09-01

    The Grüneisen ratio (Γ), i.e. the ratio of the thermal expansivity to the specific heat at constant pressure, quantifies the degree of anharmonicity of the potential governing the physical properties of a system. While Γ has been intensively explored in solid state physics, very little is known about its behavior for gases. This is most likely due to the difficulties posed in carrying out both thermal expansion and specific heat measurements in gases with high accuracy as a function of pressure and temperature. Furthermore, to the best of our knowledge a comprehensive discussion about the peculiarities of the Grüneisen ratio is still lacking in the literature. Here we report on a detailed and comprehensive overview of the Grüneisen ratio. Particular emphasis is placed on the analysis of Γ for gases. The main findings of this work are: (i) for the van der Waals gas Γ depends only on the co-volume b due to interaction effects, it is smaller than that for the ideal gas (Γ = 2/3) and diverges upon approaching the critical volume; (ii) for the Bose-Einstein condensation of an ideal boson gas, assuming the transition as first-order, Γ diverges upon approaching a critical volume, similarly to the van der Waals gas; (iii) for 4He at the superfluid transition Γ shows a singular behavior. Our results reveal that Γ can be used as an appropriate experimental tool to explore pressure-induced critical points.

  16. Gr33a Modulates Drosophila Male Courtship Preference

    PubMed Central

    Hu, Yujia; Han, Yi; Shao, Yingyao; Wang, Xingjun; Ma, Yeqing; Ling, Erjun; Xue, Lei

    2015-01-01

    In any gamogenetic species, attraction between individuals of the opposite sex promotes reproductive success that guarantees their thriving. Consequently, mate determination between two sexes is effortless for an animal. However, choosing a spouse from numerous attractive partners of the opposite sex needs deliberation. In Drosophila melanogaster, both younger virgin females and older ones are equally liked options to males; nevertheless, when given options, males prefer younger females to older ones. Non-volatile cuticular hydrocarbons, considered as major pheromones in Drosophila, constitute females' sexual attraction that act through males' gustatory receptors (Grs) to elicit male courtship. To date, only a few putative Grs are known to play roles in male courtship. Here we report that loss of Gr33a function or abrogating the activity of Gr33a neurons does not disrupt male-female courtship, but eliminates males' preference for younger mates. Furthermore, ectopic expression of human amyloid precursor protein (APP) in Gr33a neurons abolishes males' preference behavior. Such function of APP is mediated by the transcription factor forkhead box O (dFoxO). These results not only provide mechanistic insights into Drosophila male courtship preference, but also establish a novel Drosophila model for Alzheimer's disease (AD). PMID:25586066

  17. Grüneisen parameter for gases and superfluid helium

    NASA Astrophysics Data System (ADS)

    de Souza, Mariano; Menegasso, Paulo; Paupitz, Ricardo; Seridonio, Antonio; Lagos, Roberto E.

    2016-09-01

    The Grüneisen ratio (Γ), i.e. the ratio of the thermal expansivity to the specific heat at constant pressure, quantifies the degree of anharmonicity of the potential governing the physical properties of a system. While Γ has been intensively explored in solid state physics, very little is known about its behavior for gases. This is most likely due to the difficulties posed in carrying out both thermal expansion and specific heat measurements in gases with high accuracy as a function of pressure and temperature. Furthermore, to the best of our knowledge a comprehensive discussion about the peculiarities of the Grüneisen ratio is still lacking in the literature. Here we report on a detailed and comprehensive overview of the Grüneisen ratio. Particular emphasis is placed on the analysis of Γ for gases. The main findings of this work are: (i) for the van der Waals gas Γ depends only on the co-volume b due to interaction effects, it is smaller than that for the ideal gas (Γ = 2/3) and diverges upon approaching the critical volume; (ii) for the Bose–Einstein condensation of an ideal boson gas, assuming the transition as first-order, Γ diverges upon approaching a critical volume, similarly to the van der Waals gas; (iii) for 4He at the superfluid transition Γ shows a singular behavior. Our results reveal that Γ can be used as an appropriate experimental tool to explore pressure-induced critical points.

  18. Analysis of splenic Gr-1int immature myeloid cells in tumor-bearing mice.

    PubMed

    Yamamoto, Yoshiko; Ishigaki, Hirohito; Ishida, Hideaki; Itoh, Yasushi; Noda, Yoichi; Ogasawara, Kazumasa

    2008-01-01

    It is known that the number of ImC, expressing myeloid markers, CD11b and Gr-1, increase with tumor growth and ImC play a role in the escape of tumor cells from immunosurveillance in tumor-bearing mice and cancer patients. However, the mechanisms by which ImC suppress immune responses in tumor-bearing mice have not been completely elucidated. In the present study, we investigated the function of splenic ImC freshly isolated from tumor-bearing mice and splenic ImC differentiated in vitro by GM-CSF. Freshly isolated splenic ImC were divided into two groups depending on Gr-1 expression, Gr-1 high (Gr-1hi) and intermediate (Gr-1int). Freshly isolated splenic Gr-1int ImC, but not Gr-1hi ImC, from tumor-bearing mice reduced production of IFN-gamma in CD8+ T cells, but neither splenic Gr-1int ImC nor Gr-1hi ImC isolated from naive mice did. Both Gr-1int and Gr-1hi ImC differentiated in vitro by GM-CSF inhibited production of IFN-gamma in both CD8+ and CD4+ T cells. In addition, the differentiated Gr-1int ImC, one-third of which were CD11c+F4/80+ cells, and their culture supernatants suppressed proliferative responses of T cells stimulated by CD3 ligation, but the differentiated Gr-1hi ImC and their culture supernatants did not. These results suggest that Gr-1int ImC are altered to immune-suppressive cells in tumor circumstances and that they are differentiated by GM-CSF progressively into CD11c+F4/80+ cells with further suppressive activity against T cells.

  19. Constructing optimal entanglement witnesses. II. Witnessing entanglement in 4N×4N systems

    NASA Astrophysics Data System (ADS)

    Chruściński, Dariusz; Pytel, Justyna

    2010-11-01

    We provide a class of optimal nondecomposable entanglement witnesses for 4N×4N composite quantum systems or, equivalently, another construction of nondecomposable positive maps in the algebra of 4N×4N complex matrices. This construction provides natural generalization of the Robertson map. It is shown that their structural physical approximations give rise to entanglement breaking channels.

  20. Constructing optimal entanglement witnesses. II. Witnessing entanglement in 4Nx4N systems

    SciTech Connect

    Chruscinski, Dariusz; Pytel, Justyna

    2010-11-15

    We provide a class of optimal nondecomposable entanglement witnesses for 4Nx4N composite quantum systems or, equivalently, another construction of nondecomposable positive maps in the algebra of 4Nx4N complex matrices. This construction provides natural generalization of the Robertson map. It is shown that their structural physical approximations give rise to entanglement breaking channels.

  1. [Effect of humic acids on migration and transformation of NH4(+) -N in saturated aquifer].

    PubMed

    Meng, Qing-Jun; Zhang, Yan; Feng, Qi-Yan; Zhang, Shuang-Sheng

    2011-11-01

    Isothermal adsorption experiment was used to study the adsorbing process of NH4(+) -N in quartz sands under the conditions with and without humic acid; the Langmuir and Freundlich equations were used to fit the absorption result and the maximum adsorption capacity of NH4(+) -N by quarts sands was calculated. Through the soil column experiments, the concentration of NH4(+) -N, NO3(-) -N and NO2(-) -N in effluent water in the tested soil column was investigated, and the effect of humic acid on migration and transformation of NH4(+) -N in saturated aquifer was analyzed, and Pseudo-second-order Kinetics Equation and Two-step Adsorption Kinetics Rate Equation were applied to fit the kinetic processes. The results showed that both Langmuir and Freundlich models can well describe the isothermal adsorption process of NH4(+) -N on the surface of quartz sands, which means that NH4(+) -N adsorbed by the quartz sand was mainly in the form of monolayer adsorption. The humic acid could increase the adsorption capacity of NH4(+) -N on quartz sand, and the saturated adsorption capacity was 0.354 mg x g(-1) under the condition with humic acid and 0.205 mg x g(-1) with the absence of humic acid. The experiment indicated that humic acid increased the adsorption capacity of NH4(+) -N on the surface of quartz sand by increasing adsorption space in the initial stage. After saturation, humic acid influenced the migration and transformation of NH4(+) -N to NO3(-) -N and NO2(-) -N probably through providing carbon source and energy for microorganisms such as nitrifying bacteria and then resulting in lower NH4(+) -N concentration in effluent water. Both Pseudo-second-order Kinetics Equation and Two-step Adsorption Kinetics Rate Equations can well describe the process of NH4(+) -N adsorption kinetics on quartz sand (R2 = 0.997 7 and R2 = 0.998 1 with humic acid; R2 = 0.992 3 and R2 = 0.994 4 without humic acid), indicating that this process was chemical adsorption. By comparing the

  2. An alternative to Mie-Grüneisen

    NASA Astrophysics Data System (ADS)

    Anderson, William

    2015-06-01

    The Mie-Grüneisen thermal equation of state is probably the most-used EOS form in high-pressure physics, because of its simplicity and the fact that it provides a reasonable description of the thermal energy while keeping the overall EOS analytic. However, use of the Grüneisen parameter, γ, places restrictions on forms that can be used for the specific heat, while the volume dependence often ascribed to γ can be too simplistic. These shortcomings complicate attempts to realistically include explicit temperature dependence in models. I suggest an alternative using the Einstein thermal model with a correction term. The Einstein characteristic temperature θ can be obtained as a function of volume using the bulk modulus and Poisson ratio. Combination with any analytic and differentiable cold curve formulation results in a complete analytic EOS with volume and temperature as the natural independent variables. In the case of the quasiharmonic approximation with negligible electronic or magnetic thermal energy terms, internal energy or pressure can replace temperature as the second independent variable while maintaining analyticity. Use of this model is restricted to temperatures above 0.39 θ, where the Einstein and Debye specific heats are quantitatively similar. Work performed under U. S. Department of Energy Contract DE-AC52-06NA25396.

  3. Synthesis of two-dimensional titanium nitride Ti4N3 (MXene)

    NASA Astrophysics Data System (ADS)

    Urbankowski, Patrick; Anasori, Babak; Makaryan, Taron; Er, Dequan; Kota, Sankalp; Walsh, Patrick L.; Zhao, Mengqiang; Shenoy, Vivek B.; Barsoum, Michel W.; Gogotsi, Yury

    2016-06-01

    We report on the synthesis of the first two-dimensional transition metal nitride, Ti4N3-based MXene. In contrast to the previously reported MXene synthesis methods - in which selective etching of a MAX phase precursor occurred in aqueous acidic solutions - here a molten fluoride salt is used to etch Al from a Ti4AlN3 powder precursor at 550 °C under an argon atmosphere. We further delaminated the resulting MXene to produce few-layered nanosheets and monolayers of Ti4N3Tx, where T is a surface termination (F, O, or OH). Density functional theory calculations of bare, non-terminated Ti4N3 and terminated Ti4N3Tx were performed to determine the most energetically stable form of this MXene. Bare and functionalized Ti4N3 are predicted to be metallic. Bare Ti4N3 is expected to show magnetism, which is significantly reduced in the presence of functional groups.We report on the synthesis of the first two-dimensional transition metal nitride, Ti4N3-based MXene. In contrast to the previously reported MXene synthesis methods - in which selective etching of a MAX phase precursor occurred in aqueous acidic solutions - here a molten fluoride salt is used to etch Al from a Ti4AlN3 powder precursor at 550 °C under an argon atmosphere. We further delaminated the resulting MXene to produce few-layered nanosheets and monolayers of Ti4N3Tx, where T is a surface termination (F, O, or OH). Density functional theory calculations of bare, non-terminated Ti4N3 and terminated Ti4N3Tx were performed to determine the most energetically stable form of this MXene. Bare and functionalized Ti4N3 are predicted to be metallic. Bare Ti4N3 is expected to show magnetism, which is significantly reduced in the presence of functional groups. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr02253g

  4. Differential MR/GR activation in mice results in emotional states beneficial or impairing for cognition.

    PubMed

    Brinks, Vera; van der Mark, Maaike H; de Kloet, E Ron; Oitzl, Melly S

    2007-01-01

    Corticosteroids regulate stress response and influence emotion, learning, and memory via two receptors in the brain, the high-affinity mineralocorticoid (MR) and low-affinity glucocorticoid receptor (GR). We test the hypothesis that MR- and GR-mediated effects interact in emotion and cognition when a novel situation is encountered that is relevant for a learning process. By adrenalectomy and additional constant corticosterone supplement we obtained four groups of male C57BL/6J mice with differential chronic MR and GR activations. Using a hole board task, we found that mice with continuous predominant MR and moderate GR activations were fast learners that displayed low anxiety and arousal together with high directed explorative behavior. Progressive corticosterone concentrations with predominant action via GR induced strong emotional arousal at the expense of cognitive performance. These findings underline the importance of a balanced MR/GR system for emotional and cognitive functioning that is critical for mental health.

  5. Synthesis, characterization and electrochemical performance of graphene decorated with 1D NiMoO4.nH2O nanorods

    NASA Astrophysics Data System (ADS)

    Ghosh, Debasis; Giri, Soumen; Das, Chapal Kumar

    2013-10-01

    based composite, which exhibited a high specific capacitance of 367 F g-1 at 5 A g-1 current density and a high energy density of 10.32 W h kg-1 at a power density of 1125 W kg-1 accompanied with long term cyclic stability. Electronic supplementary information (ESI) available: Materials used, characterization techniques and preparation of electrode, tables containing specific capacitance, coulombic efficiency, energy density and power density values at different current densities of NiMoO4.nH2O and Gr-NiMoO4.nH2O. See DOI: 10.1039/c3nr02444j

  6. Search for 4n contributions in the reaction 14Be(CH2,X)10He

    NASA Astrophysics Data System (ADS)

    Jones, M. D.; Kohley, Z.; Baumann, T.; Christian, G.; DeYoung, P. A.; Finck, J. E.; Frank, N.; Haring-Kaye, R. A.; Kuchera, A. N.; Luther, B.; Mosby, S.; Smith, J. K.; Snyder, J.; Spyrou, A.; Stephenson, S. L.; Thoennessen, M.

    2016-03-01

    A previously published measurement of the ground state resonance of 10He, populated by a reaction of a 59 MeV/u 14Be beam on a deuterated polyethylene target, was further analyzed to search for 4n emission resulting from 2p removal. No evidence for 4n events was found. A lower limit of about 1 MeV was determined for a possible resonance in 12He.

  7. Phase stability of graphitelike BC{sub 4}N up to 2100 K and 7 GPa

    SciTech Connect

    Solozhenko, V.L.; Turkevich, V.Z.; Sato, Tadao

    1997-12-01

    Thermal phase stability of graphitelike BC{sub 4}N (g-BC{sub 4}N) has been studied up to 7 GPa and 2,100 K using in-situ powder diffraction of synchrotron radiation. It has been shown that the process of g-BC{sub 4}N decomposition at ambient pressure starts at 2,050 K and occurs to form highly ordered hexagonal graphitelike boron nitride (hBN) and disordered graphite. As the pressure increases up to 6.6 GPa, the temperature of the decomposition onset decreases to 1,070 K. At this pressure in the 1,070--1,400 K temperature range (decomposition degree of < 0.1), the decomposition products remain the same, whereas at higher temperatures, the decomposition of g-BC{sub 4}N is accompanied by the formation of cubic boron nitride (cBN) and disordered graphite. Measurement of 298 K equation of state of g-BC{sub 4}N results in a zero-pressure bulk modulus of 18.1 {+-} 0.2 GPa and its pressure derivative of 6.6 {+-} 0.1. Thermodynamic analysis has shown that the g-BC{sub 4}N decomposition is a nonequilibrium process and the phase itself is metastable.

  8. 77 FR 40511 - Safety Zone; GR Symphony Fireworks Display, Kalamazoo Lake, Saugatuck, MI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-10

    ...-366-9826. SUPPLEMENTARY INFORMATION: Table of Acronyms DHS Department of Homeland Security FR Federal... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; GR Symphony Fireworks Display, Kalamazoo... restrict vessels from a portion of Kalamazoo Lake during the GR Symphony Fireworks display. This...

  9. Performance of intermittent aeration reactor on NH4-N removal from groundwater resources.

    PubMed

    Khanitchaidecha, W; Nakamura, T; Sumino, T; Kazama, F

    2010-01-01

    To study the effect of intermittent aeration period on ammonium-nitrogen (NH4-N) removal from groundwater resources, synthetic groundwater was prepared and three reactors were operated under different conditions--"reactor A" under continuous aeration, "reactor B" under 6 h intermittent aeration, and "reactor C" under 2 h intermittent aeration. To facilitate denitrification simultaneously with nitrification, "acetate" was added as an external carbon source with step-wise increase from 0.5 to 1.5 C/N ratio, where C stands for total carbon content in the system, and N for NH4-N concentration in the synthetic groundwater. Results show that complete NH4-N removal was obtained in "reactor B" and "reactor C" at 1.3 and 1.5 C/N ratio respectively; and partial NH4-N removal in "reactor A". These results suggest that intermittent aeration at longer interval could enhance the reactor performance on NH4-N removal in terms of efficiency and low external carbon requirement. Because of consumption of internal carbon by the process, less amount of external carbon is required. Further increase in carbon in a form of acetate (1.5 to 2.5 C/N ratios) increases removal rate (represented by reaction rate coefficient (k) of kinetic equation) as well as occurrence of free cells. It suggests that the operating condition at reactor B with 1.3 C/N ratio is more appropriate for long-term operation at a pilot-scale.

  10. Immobilization of Mn and NH4 (+)-N from electrolytic manganese residue waste.

    PubMed

    Chen, Hongliang; Liu, Renlong; Liu, Zuohua; Shu, Jiancheng; Tao, Changyuan

    2016-06-01

    The objective of this work was the immobilization of soluble manganese (Mn) and ammonium nitrogen (NH4 (+)-N) leached from electrolytic manganese residue (EMR). Immobilization of Mn was investigated via carbonation using carbon dioxide (CO2) and alkaline additives. NH4 (+)-N immobilization was evaluated via struvite precipitation using magnesium and phosphate sources. Results indicated that the immobilization efficiency of Mn using CO2 and quicklime (CaO) was higher than using CO2 and sodium hydroxide (NaOH). This higher efficiency was likely due to the slower release of OH(-) during CaO hydrolysis. The immobilization efficiency of Mn was >99.99 % at the CaO:EMR mass ratio of 0.05:1 for 20-min reaction time. The struvite precipitation of NH4 (+)-N was conducted in the carbonated EMR slurry and the immobilization efficiency was 89 % using MgCl2 · 6H2O + Na3PO4 · 12H2O at the Mg:P:N molar ratio of 1.5:1.5:1 for 90-min reaction time. A leaching test showed that the concentrations of Mn and NH4 (+)-N in the filtrate of the treated EMR were 0.2 and 9 mg/L, respectively. The combined immobilization of Mn and NH4 (+)-N was an effective pretreatment method in the harmless treatment of the EMR.

  11. Evolutionary differences in food preference rely on Gr64e, a receptor for glycerol.

    PubMed

    Wisotsky, Zev; Medina, Adriana; Freeman, Erica; Dahanukar, Anupama

    2011-12-01

    Very little is known about how stimuli that are typically not rich in sugars, such as beer, trigger attractive gustatory responses in Drosophila. We identified a member of the gustatory receptor family, Gr64e, as a receptor that is required for feeding preference for beer and other sources that have fermenting yeast. We found that Gr64e is required for neuronal and behavioral responses to glycerol, an abundant component of growing yeast and fermentation products. Ectopic expression of Gr64e in an olfactory neuron conferred responsiveness to glycerol. We also found that Drosophila species that are predicted to carry pseudogenes of Gr64e had reduced glycerol sensitivity. Our results provide insight into the molecular mechanisms of feeding acceptance of yeast products and raise the possibility that Gr64e contributes to specific evolutionary variations in appetitive selectivity across Drosophila species. PMID:22057190

  12. Evolutionary differences in food preference rely on Gr64e, a receptor for glycerol.

    PubMed

    Wisotsky, Zev; Medina, Adriana; Freeman, Erica; Dahanukar, Anupama

    2011-12-01

    Very little is known about how stimuli that are typically not rich in sugars, such as beer, trigger attractive gustatory responses in Drosophila. We identified a member of the gustatory receptor family, Gr64e, as a receptor that is required for feeding preference for beer and other sources that have fermenting yeast. We found that Gr64e is required for neuronal and behavioral responses to glycerol, an abundant component of growing yeast and fermentation products. Ectopic expression of Gr64e in an olfactory neuron conferred responsiveness to glycerol. We also found that Drosophila species that are predicted to carry pseudogenes of Gr64e had reduced glycerol sensitivity. Our results provide insight into the molecular mechanisms of feeding acceptance of yeast products and raise the possibility that Gr64e contributes to specific evolutionary variations in appetitive selectivity across Drosophila species.

  13. Perpendicular magnetic anisotropy of Mn4N films fabricated by reactive sputtering method

    NASA Astrophysics Data System (ADS)

    Kabara, Kazuki; Tsunoda, Masakiyo

    2015-05-01

    Manganese nitride films were fabricated on MgO substrates by changing N2 flow ratio into Ar gas ( P N2 ) during reactive sputtering deposition of the films, and their crystal structures and magnetic properties were investigated. Single phased ɛ-Mn4N films were obtained when P N2 was 5%-9%, and the tetragonal lattice distortion was identified in all the Mn4N films (the lattice constant ratio, c/a = 0.99). Perpendicular magnetic anisotropy was observed in all the specimens. The Mn4N film, fabricated with P N2 = 8%, has a low saturation magnetization (Ms = 110 emu/cc) and relatively high magnetic anisotropic energy (Ku = 8.8 × 105 erg/cc). Both Ms and Ku of the films drastically changed with mixing other phases (α-Mn, β-Mn, η-Mn3N2, and possibly γ-Mn) by varying P N2 .

  14. Spin Polarization Inversion at Benzene-Absorbed Fe4N Surface

    PubMed Central

    Zhang, Qian; Mi, Wenbo; Wang, Xiaocha; Wang, Xuhui

    2015-01-01

    We report a first-principle study on electronic structure and simulation of the spin-polarized scanning tunneling microscopy graphic of a benzene/Fe4N interface. Fe4N is a compound ferromagnet suitable for many spintronic applications. We found that, depending on the particular termination schemes and interface configurations, the spin polarization on the benzene surface shows a rich variety of properties ranging from cosine-type oscillation to polarization inversion. Spin-polarization inversion above benzene is resulting from the hybridizations between C pz and the out-of-plane d orbitals of Fe atom. PMID:26012892

  15. The Impact of Antiaromatic Subunits in [4n+2] π-Systems: Bispentalenes with [4n+2] π-Electron Perimeters and Antiaromatic Character.

    PubMed

    Cao, Jing; London, Gábor; Dumele, Oliver; von Wantoch Rekowski, Margarete; Trapp, Nils; Ruhlmann, Laurent; Boudon, Corinne; Stanger, Amnon; Diederich, François

    2015-06-10

    Three series of stable, neutral, π-extended bispentalene derivatives, with two pentalenes fused to a central benzene or naphthalene moiety, have been prepared through a modified double carbopalladation cascade reaction. While these chromophores feature skeletons with [4n+2] π-electron perimeters, the two 8 π-electron pentalene subunits strongly influence bonding and spectral properties. (1)H NMR spectra showed large upfield shifts of the protons in the pentalene moieties, comparable to antiaromatic monobenzopentalenes. Further investigations on magnetic ring currents through NICS-XY-scans suggest a global paratropic current and a local diatropic current at the central benzene ring in two of the series, while the third series, with a central naphthalene ring, showed more localized ring currents, with stronger paratropic ring currents on the pentalene moieties. X-ray diffraction analyses revealed planar bispentalene cores with large double- and single-bond alternation in the pentalene units, characteristic for antiaromaticity, and small alternation in the central aromatic rings. In agreement with TD-DFT calculations, both optical and electrochemical data showed much smaller HOMO-LUMO energy gaps compared to other neutral, acene-like hydrocarbons with the same number of fused rings. Both experimental and computational results suggest that the molecular properties of the presented bispentalenes are dominated by the antiaromatic pentalene-subunits despite the [4n+2] π-electron perimeter of the skeletons. PMID:25978774

  16. The Impact of Antiaromatic Subunits in [4n+2] π-Systems: Bispentalenes with [4n+2] π-Electron Perimeters and Antiaromatic Character.

    PubMed

    Cao, Jing; London, Gábor; Dumele, Oliver; von Wantoch Rekowski, Margarete; Trapp, Nils; Ruhlmann, Laurent; Boudon, Corinne; Stanger, Amnon; Diederich, François

    2015-06-10

    Three series of stable, neutral, π-extended bispentalene derivatives, with two pentalenes fused to a central benzene or naphthalene moiety, have been prepared through a modified double carbopalladation cascade reaction. While these chromophores feature skeletons with [4n+2] π-electron perimeters, the two 8 π-electron pentalene subunits strongly influence bonding and spectral properties. (1)H NMR spectra showed large upfield shifts of the protons in the pentalene moieties, comparable to antiaromatic monobenzopentalenes. Further investigations on magnetic ring currents through NICS-XY-scans suggest a global paratropic current and a local diatropic current at the central benzene ring in two of the series, while the third series, with a central naphthalene ring, showed more localized ring currents, with stronger paratropic ring currents on the pentalene moieties. X-ray diffraction analyses revealed planar bispentalene cores with large double- and single-bond alternation in the pentalene units, characteristic for antiaromaticity, and small alternation in the central aromatic rings. In agreement with TD-DFT calculations, both optical and electrochemical data showed much smaller HOMO-LUMO energy gaps compared to other neutral, acene-like hydrocarbons with the same number of fused rings. Both experimental and computational results suggest that the molecular properties of the presented bispentalenes are dominated by the antiaromatic pentalene-subunits despite the [4n+2] π-electron perimeter of the skeletons.

  17. Genomic redistribution of GR monomers and dimers mediates transcriptional response to exogenous glucocorticoid in vivo.

    PubMed

    Lim, Hee-Woong; Uhlenhaut, N Henriette; Rauch, Alexander; Weiner, Juliane; Hübner, Sabine; Hübner, Norbert; Won, Kyoung-Jae; Lazar, Mitchell A; Tuckermann, Jan; Steger, David J

    2015-06-01

    Glucocorticoids (GCs) are commonly prescribed drugs, but their anti-inflammatory benefits are mitigated by metabolic side effects. Their transcriptional effects, including tissue-specific gene activation and repression, are mediated by the glucocorticoid receptor (GR), which is known to bind as a homodimer to a palindromic DNA sequence. Using ChIP-exo in mouse liver under endogenous corticosterone exposure, we report here that monomeric GR interaction with a half-site motif is more prevalent than homodimer binding. Monomers colocalize with lineage-determining transcription factors in both liver and primary macrophages, and the GR half-site motif drives transcription, suggesting that monomeric binding is fundamental to GR's tissue-specific functions. In response to exogenous GC in vivo, GR dimers assemble on chromatin near ligand-activated genes, concomitant with monomer evacuation of sites near repressed genes. Thus, pharmacological GCs mediate gene expression by favoring GR homodimer occupancy at classic palindromic sites at the expense of monomeric binding. The findings have important implications for improving therapies that target GR.

  18. Genomic redistribution of GR monomers and dimers mediates transcriptional response to exogenous glucocorticoid in vivo.

    PubMed

    Lim, Hee-Woong; Uhlenhaut, N Henriette; Rauch, Alexander; Weiner, Juliane; Hübner, Sabine; Hübner, Norbert; Won, Kyoung-Jae; Lazar, Mitchell A; Tuckermann, Jan; Steger, David J

    2015-06-01

    Glucocorticoids (GCs) are commonly prescribed drugs, but their anti-inflammatory benefits are mitigated by metabolic side effects. Their transcriptional effects, including tissue-specific gene activation and repression, are mediated by the glucocorticoid receptor (GR), which is known to bind as a homodimer to a palindromic DNA sequence. Using ChIP-exo in mouse liver under endogenous corticosterone exposure, we report here that monomeric GR interaction with a half-site motif is more prevalent than homodimer binding. Monomers colocalize with lineage-determining transcription factors in both liver and primary macrophages, and the GR half-site motif drives transcription, suggesting that monomeric binding is fundamental to GR's tissue-specific functions. In response to exogenous GC in vivo, GR dimers assemble on chromatin near ligand-activated genes, concomitant with monomer evacuation of sites near repressed genes. Thus, pharmacological GCs mediate gene expression by favoring GR homodimer occupancy at classic palindromic sites at the expense of monomeric binding. The findings have important implications for improving therapies that target GR. PMID:25957148

  19. Electrical detection of magnetic domain wall in Fe4N nanostrip by negative anisotropic magnetoresistance effect

    NASA Astrophysics Data System (ADS)

    Gushi, Toshiki; Ito, Keita; Higashikozono, Soma; Takata, Fumiya; Oosato, Hirotaka; Sugimoto, Yoshimasa; Toko, Kaoru; Honda, Syuta; Suemasu, Takashi

    2016-09-01

    The magnetic structure of the domain wall (DW) of a 30-nm-thick Fe4N epitaxial film with a negative spin polarization of the electrical conductivity is observed by magnetic force microscopy and is well explained by micromagnetic simulation. The Fe4N film is grown by molecular beam epitaxy on a SrTiO3(001) substrate and processed into arc-shaped ferromagnetic nanostrips 0.3 μm wide by electron beam lithography and reactive ion etching with Cl2 and BCl3 plasma. Two electrodes mounted approximately 12 μm apart on the nanostrip register an electrical resistance at 8 K. By changing the direction of an external magnetic field (0.2 T), the presence or absence of a DW positioned in the nanostrip between the two electrodes can be controlled. The resistance is increased by approximately 0.5 Ω when the DW is located between the electrodes, which signifies the negative anisotropic magnetoresistance effect of Fe4N. The electrical detection of the resistance change is an important step toward the electrical detection of current-induced DW motion in Fe4N.

  20. Comparison of performance of genetics 4N6 FLOQSwabs™ with or without surfactant to rayon swabs.

    PubMed

    Frippiat, Christophe; Noel, Fabrice

    2016-08-01

    The collection of traces is the first step in the process of forensic genetics analysis. Currently, several different techniques are used (eg. gauze). Nevertheless, swabbing appears to be the most common of these. In a second step, the sampling devices should allow the use of preliminary tests in combination with an immunological confirmatory test (e.g. Hexagon Obti or Hemdirect). Our previous study shows that sampling with Genetics 4N6FLOQswabs™ coated with surfactant reduces by a factor of at least 100 the detection threshold of blood using two immunological tests. The aim of this work was to compare the ability to recover blood trace and the compatibility with immunological confirmatory test of various Genetics 4N6FLOQswabs™ nylon flocked swabs with or without surfactant. The results obtain in this study show that Genetics 4N6FLOQswabs™ not coated with surfactant and Human DNA free FLOQswabs™ were suitable for the used in combination with immunological blood detection tests. Nevertheless, the Genetics 4N6FLOQswabs™ not surfactant coated give a better blood trace recovery. PMID:27314974

  1. B4N and Fe3BN nitrides bands structure and theoretical determination of bulk modulus

    NASA Astrophysics Data System (ADS)

    dos Santos, A. V.

    2007-06-01

    With the evolution of material science there was some technological evolution as well as the need of finding new links which could be applied to diverse areas of knowledge. Thus, in this article, we study nitrides bands structures which contain boron, in two different stoichiometries Fe3BN and B4N. The choice of these compounds is meant to plan new links and to understand nitrides fundamental state properties facing these new crystalline structures. In order to resolve the compound band structure we used the method of linear Muffin Tin orbital (LMTO), with atomic sphere approximation (ASA). By using this method we obtained the energy of formation as a function of the lattice parameter as one of the results. We find the equilibrium lattice parameter of 6.9755 a.u., for the Fe3BN nitride, and in B4N, we have 6.8589 a.u. We also discuss in this article the charge transference between sites and the influence of pressure on the compound properties, as well as the Bulk modulus that is 239.82 GPa for Fe3BN and 105.48 GPa for B4N. We show the behaviour of the density of states (DOS) of the new band structure found for the proposed crystalline structure Fe3BN, in which the B atom replace the Fe atom in the corner of the structure γ‧- Fe4N.

  2. Transverse anisotropic magnetoresistance effects in pseudo-single-crystal γ'-Fe4N thin films

    NASA Astrophysics Data System (ADS)

    Kabara, Kazuki; Tsunoda, Masakiyo; Kokado, Satoshi

    2016-05-01

    Transverse anisotropic magnetoresistance (AMR) effects, for which magnetization is rotated in an orthogonal plane to the current direction, were investigated at various temperatures, in order to clarify the structural transformation from a cubic to a tetragonal symmetry in a pseudo-single-crystal Fe4N film, which is predicted from the usual in-plane AMR measurements by the theory taking into account the spin-orbit interaction and crystal field splitting of 3d bands. According to a phenomenological theory of AMR, which derives only from the crystal symmetry, a cos 2θ component ( C2 tr ) exists in transverse AMR curves for a tetragonal system but does not for a cubic system. In the Fe4N film, the C2 tr shows a positive small value (0.12%) from 300 K to 50 K. However, the C2 t r increases to negative value below 50 K and reaches to -2% at 5 K. The drastic increasing of the C2 tr demonstrates the structural transformation from a cubic to a tetragonal symmetry below 50 K in the Fe4N film. In addition, the out-of-plane and in-plane lattice constants (c and a) were precisely determined with X-ray diffraction at room temperature using the Nelson-Riely function. As a result, the positive small C2 t r above 50 K is attributed to a slightly distorted Fe4N lattice (c/a = 1.002).

  3. Comparison of performance of genetics 4N6 FLOQSwabs™ with or without surfactant to rayon swabs.

    PubMed

    Frippiat, Christophe; Noel, Fabrice

    2016-08-01

    The collection of traces is the first step in the process of forensic genetics analysis. Currently, several different techniques are used (eg. gauze). Nevertheless, swabbing appears to be the most common of these. In a second step, the sampling devices should allow the use of preliminary tests in combination with an immunological confirmatory test (e.g. Hexagon Obti or Hemdirect). Our previous study shows that sampling with Genetics 4N6FLOQswabs™ coated with surfactant reduces by a factor of at least 100 the detection threshold of blood using two immunological tests. The aim of this work was to compare the ability to recover blood trace and the compatibility with immunological confirmatory test of various Genetics 4N6FLOQswabs™ nylon flocked swabs with or without surfactant. The results obtain in this study show that Genetics 4N6FLOQswabs™ not coated with surfactant and Human DNA free FLOQswabs™ were suitable for the used in combination with immunological blood detection tests. Nevertheless, the Genetics 4N6FLOQswabs™ not surfactant coated give a better blood trace recovery.

  4. C4N2 ice in Titan’s atmosphere: reality or myth?

    NASA Astrophysics Data System (ADS)

    Anderson, Carrie; Samuelson, Robert E.; Achterberg, Richard K.; Flasar, F. M.

    2014-11-01

    Voyager 1 IRIS detected a spectral emission feature at 478 cm-1 in Titan’s atmosphere at high northern latitudes. Now one Titan year later we rediscovered it in Cassini CIRS limb spectra at 70°N. Thus far the feature has always been associated with the lower polar stratosphere during early northern spring. No known trace organic vapor in Titan’s atmosphere has a spectral feature at 478 cm-1, and the only known or suspected condensate that does is C4N2 ice. However, the C4N2 ν8 and ν9 vapor features at 472 cm-1 and 108 cm-1, respectively, have never been observed in Titan’s atmosphere, leading to a C4N2 vapor upper limit at least 2 orders of magnitude lower than equilibrium with the ice phase would suggest. In this study we analyze the spectral shapes and strengths of the 478 cm-1 feature in the IRIS and CIRS data sets in an effort to determine particle sizes, mole fractions, and vertical distributions of the putative condensate cloud responsible for the feature, and then discuss the pros and cons of its identify with C4N2 ice.

  5. The Late Peaking Afterglow of GR8 100418A

    NASA Technical Reports Server (NTRS)

    Marshall, Frank; Antonelli, L. A.; Burrows, D. N.; Covino, S.; dePasquale, M.; Evans, P. A.; Fugazza, D.; Holland, S. T.; Liang, E. W.; OBrien, P. T.; Osborne, J. P.; Pagani, C.; Sakamoto, T.; Siegel, M. H.; Wu, X. F.; Zhang, B.

    2010-01-01

    GRB 100418A is a long Gamma-Ray Burst at redshift z=0.6235 discovered with the Swift Gamma-Ray Burst Explorer with unusual optical and X-ray light curves ' After an initial short-lived, rapid decline in X-rays, the optical and X-ray light curves observed with Swift are approximately flat or rising slightly out to at least approx.7 ks after the trigger, peak at approx.50 ks, and then follow an approximately power-law decay. Such a long optical plateau and late peaking is rarely seen in 6R8 afterglows. Observations with REM during a gap in the Swift coverage indicate a bright optical flare at approx.25 ks, The long plateau phase of the afterglow is interpreted using either a model with continuous injection of energy into the forward shock of the burst or a model in which the 'et of the burst is viewed off-axis. In both models the isotropic kinetic energy in the late afterglow after the plateau phase is >100 times the 10(exp 51) erg of the prompt isotropic gamma-ray energy release. The energy injection model is favored because the off-axis 'et model would require the intrinsic $T f801$ for the GR8 'et viewed on-axis to be very short, approx.10 ms, and the intrinsic isotropic gamma-ray energy release and the true jet energy to be much higher than the typical values of known short GRBs^ The non-detection of a 'et break up to approx.2 Ms indicates a jet half-opening angle of at least 14 degrees, and a relatively high collimation-corrected 'et energy of at least 10(exp 52) erg.

  6. Endocrine-Disrupting Potential of Bisphenol A, Bisphenol A Dimethacrylate, 4-n-Nonylphenol, and 4-n-Octylphenol in Vitro: New Data and a Brief Review

    PubMed Central

    Bonefeld-Jørgensen, Eva C.; Long, Manhai; Hofmeister, Marlene V.; Vinggaard, Anne Marie

    2007-01-01

    Background An array of environmental compounds is known to possess endocrine disruption (ED) potentials. Bisphenol A (BPA) and bisphenol A dimethacrylate (BPA-DM) are monomers used to a high extent in the plastic industry and as dental sealants. Alkylphenols such as 4-n-nonylphenol (nNP) and 4-n-octylphenol (nOP) are widely used as surfactants. Objectives We investigated the effect in vitro of these four compounds on four key cell mechanisms including transactivation of a) the human estrogen receptor (ER), b) the human androgen receptor (AR), c) the aryl hydrocarbon receptor (AhR), and d) aromatase activity. Results All four compounds inhibited aromatase activity and were agonists and antagonists of ER and AR, respectively. nNP increased AhR activity concentration-dependently and further increased the 2,3,7,8-tetrachlorodibenzo-p-dioxin AhR action. nOP caused dual responses with a weak increased and a decreased AhR activity at lower (10−8 M) and higher concentrations (10−5–10−4 M), respectively. AhR activity was inhibited with BPA (10−5–10−4 M) and weakly increased with BPA-DM (10−5 M), respectively. nNP showed the highest relative potency (REP) compared with the respective controls in the ER, AhR, and aromatase assays, whereas similar REP was observed for the four chemicals in the AR assay. Conclusion Our in vitro data clearly indicate that the four industrial compounds have ED potentials and that the effects can be mediated via several cellular pathways, including the two sex steroid hormone receptors (ER and AR), aromatase activity converting testosterone to estrogen, and AhR; AhR is involved in syntheses of steroids and metabolism of steroids and xenobiotic compounds. PMID:18174953

  7. Comparative study of the Grüneisen parameter for 28 pure fluids.

    PubMed

    Mausbach, Peter; Köster, Andreas; Rutkai, Gábor; Thol, Monika; Vrabec, Jadran

    2016-06-28

    The Grüneisen parameter γG is widely used for studying thermal properties of solids at high pressure and also has received increasing interest in different applications of non-ideal fluid dynamics. Because there is a lack of systematic studies of the Grüneisen parameter in the entire fluid region, this study aims to fill this gap. Grüneisen parameter data from molecular modelling and simulation are reported for 28 pure fluids and are compared with results calculated from fundamental equations of state that are based on extensive experimental data sets. We show that the Grüneisen parameter follows a general density-temperature trend and characterize the fluid systems by specifying a span of minimum and maximum values of γG. Exceptions to this trend can be found for water. PMID:27369525

  8. Extending Clause Learning of SAT Solvers with Boolean Gröbner Bases

    NASA Astrophysics Data System (ADS)

    Zengler, Christoph; Küchlin, Wolfgang

    We extend clause learning as performed by most modern SAT Solvers by integrating the computation of Boolean Gröbner bases into the conflict learning process. Instead of learning only one clause per conflict, we compute and learn additional binary clauses from a Gröbner basis of the current conflict. We used the Gröbner basis engine of the logic package Redlog contained in the computer algebra system Reduce to extend the SAT solver MiniSAT with Gröbner basis learning. Our approach shows a significant reduction of conflicts and a reduction of restarts and computation time on many hard problems from the SAT 2009 competition.

  9. Gr1intCD11b+ Myeloid-Derived Suppressor Cells in Mycobacterium tuberculosis Infection

    PubMed Central

    Obregón-Henao, Andrés; Henao-Tamayo, Marcela; Orme, Ian M.; Ordway, Diane J.

    2013-01-01

    Background Tuberculosis is one of the world’s leading killers, stealing 1.4 million lives and causing 8.7 million new and relapsed infections in 2011. The only vaccine against tuberculosis is BCG which demonstrates variable efficacy in adults worldwide. Human infection with Mycobacterium tuberculosis results in the influx of inflammatory cells to the lung in an attempt to wall off bacilli by forming a granuloma. Gr1intCD11b+ cells are called myeloid-derived suppressor cells (MDSC) and play a major role in regulation of inflammation in many pathological conditions. Although MDSC have been described primarily in cancer their function in tuberculosis remains unknown. During M. tuberculosis infection it is crucial to understand the function of cells involved in the regulation of inflammation during granuloma formation. Understanding their relative impact on the bacilli and other cellular phenotypes is necessary for future vaccine and drug design. Methodology/Principal Findings We compared the bacterial burden, lung pathology and Gr1intCD11b+ myeloid-derived suppressor cell immune responses in M. tuberculosis infected NOS2-/-, RAG-/-, C3HeB/FeJ and C57/BL6 mice. Gr-1+ cells could be found on the edges of necrotic lung lesions in NOS2-/-, RAG-/-, and C3HeB/FeJ, but were absent in wild-type mice. Both populations of Gr1+CD11b+ cells expressed high levels of arginase-1, and IL-17, additional markers of myeloid derived suppressor cells. We then sorted the Gr1hi and Gr1int populations from M. tuberculosis infected NOS-/- mice and placed the sorted both Gr1int populations at different ratios with naïve or M. tuberculosis infected splenocytes and evaluated their ability to induce activation and proliferation of CD4+T cells. Our results showed that both Gr1hi and Gr1int cells were able to induce activation and proliferation of CD4+ T cells. However this response was reduced as the ratio of CD4+ T to Gr1+ cells increased. Our results illustrate a yet unrecognized interplay

  10. Ammonia Inhibition of Plasmid pRmeGR4a Conjugal Transfer between Rhizobium meliloti Strains

    PubMed Central

    Herrera-Cervera, J. A.; Olivares, J.; Sanjuan, J.

    1996-01-01

    We have examined nutritional factors influencing conjugal transfer of the two nonsymbiotic large plasmids, pRmeGR4a and pRmeGR4b, of Rhizobium meliloti GR4. To monitor transfer, each plasmid was tagged with a different antibiotic resistance marker. Transfer of plasmid pRmeGR4b was dependent upon the presence of plasmid pRmeGR4a on the same donor cell. Transconjugants for pRmeGR4b were obtained at frequencies 5-to 10-fold higher than transconjugants carrying both plasmids, indicating that mobilization of pRmeGR4b by pRmeGR4a probably occurred in trans. Conjugal transfer of the tagged plasmids between R. meliloti strains was tested on minimal medium supplemented with single amino acids, nitrate, or ammonium as the single nitrogen source. A higher number of transconjugants was obtained when glutamate was the only nitrogen source, whereas conjugation was virtually undetectable on ammonium. No relationship was found between donor or recipient growth rate and plasmid transfer rate on a given nitrogen source. Furthermore, in media containing both glutamate and ammonium as nitrogen sources, transfer was reduced almost 100-fold compared with that in media containing glutamate alone. Inhibition was readily detected at 2.5 mM or higher concentrations of either ammonium chloride or ammonium sulfate and appeared to be specific for exogenously supplied ammonium. Inhibition of conjugal transfer between R. meliloti strains by ammonium was only observed for rhizobial plasmids, not for a heterologous plasmid such as RP4. Apparently, ammonium did not affect the plasmid-encoded transfer machinery, as it had no influence on rhizobial plasmid transfer from R. meliloti to Agrobacterium tumefaciens. The effect of ammonium seemed to take place on R. meliloti recipient cells, thereby reducing the efficiency of plasmid conjugation, probably by affecting mating pair formation or stabilization. PMID:16535284

  11. HDAC6 regulates GR signaling in serotonin pathways with critical impact on stress resilience

    PubMed Central

    Espallergues, Julie; Teegarden, Sarah L.; Veerakumar, Avin; Boulden, Janette; Challis, Collin; Jochems, Jeanine; Chan, Michael; Petersen, Tess; Deneris, Evan; Matthias, Patrick; Hahn, Chang-Gyu; Lucki, Irwin; Beck, Sheryl G.; Berton, Olivier

    2012-01-01

    Genetic variations in certain components of the glucocorticoid receptor (GR) chaperone complex have been associated with the development of stress-related affective disorders and individual variability in therapeutic responses to antidepressants. Mechanisms that link GR chaperoning and stress susceptibility are not well understood. Here, we show that the effects of glucocorticoid hormones on socioaffective behaviors are critically regulated via reversible acetylation of Hsp90, a key component of the GR chaperone complex. We provide pharmacological and genetic evidence indicating that the cytoplasmic lysine deacetylase HDAC6 controls Hsp90 acetylation in the brain, and thereby modulates Hsp90-GR protein-protein interactions, as well as hormone- and stress-induced GR translocation, with a critical impact on GR downstream signaling and behavior. Pet1-Cre driven deletion of HDAC6 in serotonin neurons, the densest HDAC6-expressing cell group in the mouse brain, dramatically reduced acute anxiogenic effects of the glucocorticoid hormone corticosterone in the open field, elevated plus maze, and social interaction tests. Serotonin-selective depletion of HDAC6 also blocked the expression of social avoidance in mice exposed to chronic social defeat and concurrently prevented the electrophysiological and morphological changes induced, in serotonin neurons, by this murine model of traumatic stress. Together, these results identify HDAC6 inhibition as a potential new strategy for pro-resilience and antidepressant interventions through regulation of the Hsp90-GR heterocomplex and focal prevention of GR signaling in serotonin pathways. Our data thus uncover an alternate mechanism by which pan-HDAC inhibitors may regulate stress-related behaviors independently of their action on histones. PMID:22457490

  12. Octopamine neuromodulation regulates Gr32a-linked aggression and courtship pathways in Drosophila males.

    PubMed

    Andrews, Jonathan C; Fernández, María Paz; Yu, Qin; Leary, Greg P; Leung, Adelaine K W; Kavanaugh, Michael P; Kravitz, Edward A; Certel, Sarah J

    2014-05-01

    Chemosensory pheromonal information regulates aggression and reproduction in many species, but how pheromonal signals are transduced to reliably produce behavior is not well understood. Here we demonstrate that the pheromonal signals detected by Gr32a-expressing chemosensory neurons to enhance male aggression are filtered through octopamine (OA, invertebrate equivalent of norepinephrine) neurons. Using behavioral assays, we find males lacking both octopamine and Gr32a gustatory receptors exhibit parallel delays in the onset of aggression and reductions in aggression. Physiological and anatomical experiments identify Gr32a to octopamine neuron synaptic and functional connections in the suboesophageal ganglion. Refining the Gr32a-expressing population indicates that mouth Gr32a neurons promote male aggression and form synaptic contacts with OA neurons. By restricting the monoamine neuron target population, we show that three previously identified OA-Fru(M) neurons involved in behavioral choice are among the Gr32a-OA connections. Our findings demonstrate that octopaminergic neuromodulatory neurons function as early as a second-order step in this chemosensory-driven male social behavior pathway.

  13. Usinage des composites a matrice d'alliage d'aluminium GrA-Ni(Reg)

    NASA Astrophysics Data System (ADS)

    Songmene, Victor

    2001-07-01

    Aluminium Metal Matrix Composites (MMC) reinforced with ceramic particles have been increasingly developed during the last decade. Ceramic particles used as reinforcement that improve the wear resistance of composites also cause high abrasive wear on cutting tools. This thesis investigates the machinability of graphitic MMC consisting of an aluminium alloy matrix reinforced with both soft nickel-coated graphite particles and hard (SiC or Al2O 3) particles. These composites were developed seven years ago, but the lack of optimised machining data to machine GrA-NIRTM composites cost effectively have been slowing down their use in engineering applications. Turning, milling and drilling tests were performed to evaluate the machinability of different GrA-NIRTM and to establish cutting conditions. It was found that: (1) The machinability of GrA-NiRTM composites depends on the nature and the percentage of the reinforcing particles. GrA-NiRTM containing alumina and graphite are easier to machine than those reinforced with silicon carbide and graphite. (2) Polycrystalline (PCD) and diamond-coated carbide (DCC) are the tool material of choice for machining GrA-NiRTM. DCC tools are most cost effective while PCD tools produce better part finishes. (3) The cutting force required to machine the GrA-NIRTM composites is similar to that used for aluminium alloys such as Al 380.

  14. Laser Spectroscopy of GdPO4 . nH2O:Eu Nanomaterials.

    PubMed

    Lu, Shaozhe; Zhang, Jiahua; Zhang, Jishen; Shulin, Zhang E; Zhao, Haifeng; Luo, Yongshi

    2016-04-01

    One-dimensional GdPO4 . nH2O:Eu nanowires and nanorods of different sizes and the same structure were synthesized by hydrothermal method. Nanowire and nanorods had width and length of about 10 nm/50 nm and 80 nm/1 µm, respectively. Adjusting reaction system PH value by adding alkali metal NaOH, the size and shape of the product can be tuned. The high resolution spectra, excitation spectra, and laser selective excitation spectra at low temperature were determined. Nanorod compared with nanowire, photoluminescence was enhanced, and the excitation spectrum and laser selective excitation spectra were broadened. These results suggest that Eu3+ in GdPO4 . nH20 nanorod and nanowire were located in different local environments. PMID:27451675

  15. Extrinsic anomalous Hall effect in epitaxial Mn{sub 4}N films

    SciTech Connect

    Meng, M.; Wu, S. X. Ren, L. Z.; Zhou, W. Q.; Wang, Y. J.; Wang, G. L.; Li, S. W.

    2015-01-19

    Anomalous Hall effect (AHE) in ferrimagnetic Mn{sub 4}N epitaxial films grown by molecular-beam epitaxy is investigated. The longitudinal conductivity σ{sub xx} is within the superclean regime, indicating Mn{sub 4}N is a highly conducting material. We further demonstrate that the AHE signal in 40-nm-thick films is mainly due to the extrinsic contributions based on the analysis fitted by ρ{sub AH}=a′ρ{sub xx0}+bρ{sub xx}{sup 2} and σ{sub AH}∝σ{sub xx}. Our study not only provide a strategy for further theoretical work on antiperovskite manganese nitrides but also shed promising light on utilizing their extrinsic AHE to fabricate spintronic devices.

  16. Search for coupling in ferromagnetic/superconducting multilayers: Fe{sub 4}N/NbN

    SciTech Connect

    Mattson, J.E.; Potter, C.D.; Conover, M.J.; Sowers, C.H.; Bader, S.D.

    1997-09-01

    Structural, magnetic, and superconducting properties of ferromagnetic/superconducting multilayers of Fe{sub 4}N/NbN are examined. The onset of superconductivity occurs at NbN layer thickness of {approximately}100 {Angstrom}. Below this thickness ferromagnetism of the Fe{sub 4}N layers is observed. Above this thickness superconductivity of the NbN is also observed, but there is no evidence for interlayer magnetic or superconductive coupling. The results are used in the formulation of guidelines for future searches of novel interlayer coupling phenomena. The superconducting critical field curves are reasonably well described within the framework of the theory for ferromagnetic/superconducting multilayers. {copyright} {ital 1997 American Vacuum Society.}

  17. Structure determination of (Fe3O4)n+(n = 1 - 3) clusters via DFT

    NASA Astrophysics Data System (ADS)

    Li, Yanhua; Cai, Congzhong; Zhao, Chengjun; Gu, Yonghong

    2016-07-01

    In virtue of the particle swarm optimization (PSO) algorithm, the global minimum candidate structures with the lowest energy for (Fe3O4)n(n = 1 - 3) clusters were obtained by first-principles structural searches. The geometric structures and spin configurations of three cationic (Fe3O4)n+(n = 1 - 3) clusters have been identified for the first time by comparing the experimental IR spectra with the calculated results from density functional theory by using different exchange-correlation functionals. It is found that the lowest energy structures of these clusters are of a shape of hat, boat and tower, respectively, with a ferrimagnetic arrangement of spins, and M06L functional is more suitable for Fe3O4 clusters than other ones.

  18. 4'''-N-demethylspiramycin derivatives: synthesis and evaluation of effectiveness against drug-resistant bacteria.

    PubMed

    Sunazuka, Toshiaki; Shudo, Hiroko; Nagai, Kenichiro; Yoshida, Kiminari; Yamaguchi, Yukie; Hanaki, Hideaki; Omura, Satoshi

    2008-03-01

    18-amino-4''-O-benzoyl-4'''-N-demethyl-18-deoxospiramycins were designed and synthesized. Synthetic strategy involved selective demethylation of the dimethylamino group in forosamine, benzoylation of the hydroxyl group at the C4'' position and reductive N-amination of the formyl group. Antibacterial characteristics of spiramycin derivatives were tested. The derivatives exhibited promising activity against drug-resistant bacterial strains. PMID:18503196

  19. Bu4N+ alkoxide-initiated/autocatalytic addition reactions with organotrimethylsilanes.

    PubMed

    Das, Manas; O'Shea, Donal F

    2014-06-20

    The use of Me3SiO(-)/Bu4N(+) as a general activator of organotrimethylsilanes for addition reactions has been established. The broad scope of the method offers trimethylsilanes (including acetate, allyl, propargyl, benzyl, dithiane, heteroaryl, and aryl derivatives) as bench-stable organometallics that can be readily utilized as carbanion equivalents for synthesis. Reactions are achieved at rt without the requirement of specialized precautions that are commonplace for other organometallics.

  20. Nqrs Data for C8H12BCuF4N4 (Subst. No. 1102)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume A `Substances Containing Ag … C10H15' of Volume 48 `Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III `Condensed Matter'. It contains an extract of Section `3.2 Data tables' of the Chapter `3 Nuclear quadrupole resonance data' providing the NQRS data for C8H12BCuF4N4 (Subst. No. 1102)

  1. Anomalous Hall effects in pseudo-single-crystal γ'-Fe4N thin films

    NASA Astrophysics Data System (ADS)

    Kabara, Kazuki; Tsunoda, Masakiyo; Kokado, Satoshi

    2016-05-01

    The anomalous Hall effects (AHE) were investigated at various temperatures for the pseudo-single-crystal Fe4N films, deposited on MgO substrates with changing the degree of order (S) of the nitrogen site. Both the anomalous Hall resistivity and the longitudinal resistivity simply decrease with lowering temperature for all the specimens. The AHE of the Fe4N films is presumed to arise from an intrinsic mechanism because of the relationship between the anomalous Hall resistivity and longitudinal resistivity. The anomalous Hall conductivity, σAH, exhibits a specific behavior at low temperature. In the case of the film with S = 0.93, the σAH drastically drops below 50 K, while it simply increases with lowering temperature in the range of 50-300 K. This low-temperature anomaly decays with decreasing S of the film and nearly vanishes in the films with low S. The threshold temperature and the dependence on S of the low-temperature anomaly of the σAH well correspond to those of the anisotropic magnetoresistance effects in the Fe4N films, reported in the literatures. From these results, it is suggested that the low-temperature anomaly of the σAH originates from the crystal field effect which reflects the structural transformation from a cubic to a tetragonal symmetry below 50 K and provides a modulation of the orbital angular momentum of the 3d orbitals at the Fermi level.

  2. Nano-crystalline silicon solar cell architecture with absorption at the classical 4n2 limit

    SciTech Connect

    Biswas, Rana; Xu, Chun

    2011-07-04

    We develop a periodically patterned conformal photonic-plasmonic crystal based solar architecture for a nano-crystalline silicon solar cell, through rigorous scattering matrix simulations. The solar cell architecture has a periodic array of tapered silver nano-pillars as the back-reflector coupled with a conformal periodic structure at the top of the cell. The absorption and maximal current, averaged over the entire range of wavelengths, for this solar cell architecture is at the semi-classical 4n{sup 2} limit over a range of common thicknesses (500-1500 nm) and slightly above the 4n{sup 2} limit for a 500 nm nc-Si cell. The absorption exceeds the 4n{sup 2} limit, corrected for reflection loss at the top surface. The photonic crystal cell current is enhanced over the flat Ag back-reflector by 60%, for a thick 1000 nm nc-Si layer, where predicted currents exceed 31 mA/cm{sup 2}. The conformal structure at the top surface focuses light within the absorber layer. There is plasmonic concentration of light, with intensity enhancements exceeding 7, near the back reflector that substantially enhances absorption.

  3. Arsenic at very low concentrations alters glucocorticoid receptor (GR)-mediated gene activation but not GR-mediated gene repression: complex dose-response effects are closely correlated with levels of activated GR and require a functional GR DNA binding domain.

    PubMed

    Bodwell, Jack E; Kingsley, Lauren A; Hamilton, Joshua W

    2004-08-01

    Arsenic (As) contamination of drinking water is considered a principal environmental health threat throughout the world. Chronic intake is associated with an increased risk of cancer, diabetes, and cardiovascular disease, and recent studies suggest increased health risks at levels as low as 5-10 ppb. We report here that 0.05-1 microM (6-120 ppb) As showed stimulatory effects on glucocorticoid receptor (GR)-mediated gene activation in rat EDR3 hepatoma cells of both the endogenous tyrosine aminotransferase (TAT) gene and the reporter genes containing TAT glucocorticoid response elements. At slightly higher concentrations (1-3 microM), the effects of As became inhibitory. Thus, over this narrow concentration range, the effects of As changed from a 2- to 4-fold stimulation to a greater than 2-fold suppression in activity. Interestingly, the inhibitory effect of GR on both AP1- and NF-kappa B-mediated gene activation was not affected by As. The magnitude of GR stimulation and inhibition by As was highly dependent on the cellular level of hormone-activated GR. Mutational deletion studies indicated that the central DNA binding domain (DBD) of GR is the minimal region required for the As effect and does not require free sulfhydryls. Point mutations located within the DBD that have known structural consequences significantly altered the GR response to As. In particular, point mutations in the DBD that confer a DNA-bound GR confirmation abolished the low dose As stimulatory effect but enhanced the inhibitory response, further indicating that the DBD is important for mediating these As effects. PMID:15310238

  4. Search for evidence of C4N2 on Titan with new spectroscopic data

    NASA Astrophysics Data System (ADS)

    Jolly, A.; Benilan, Y.; Fayt, A.; Nixon, C.; Jennings, D.; Anderson, C.; Bjoraker, G.

    2013-09-01

    The Composite Infrared Spectrometer (CIRS) onboard Cassini has recorded spectra in the far and mid-infrared since 2004 with a spectral resolution of up to 0.5 cm-1. Mismatch between observed spectra and model spectra obtained from the available line lists has led us to study the spectroscopic parameters of HC3N, C4H2 and C2N2, the longest gas phase carbon chains observed so far on Titan. Band intensities, hot band intensities, and line lists were systematically verified by comparison with new laboratory spectra. Erroneous band intensities as well as an absence or shortage of hot band transitions in the line lists leading to model-data mismatches and inaccurate quantifications have been found. Improvement in the spectroscopic parameters has led to the detection of 13C isotopologues of HC3N [1] and C4H2 [2]. The study on C2N2 opens the way to the detection of 15N isotopologues whose abundances could give some clues to understand the origin and the evolution of Titan's atmosphere [3]. Also, the higher accuracy of spectroscopic data used to model CIRS spectra will facilitate the search for longer carbon chains on Titan such as HC5N, C6H2 and C4N2. Our recent measurements obtained at the SOLEIL synchrotron far infrared beam line of band intensities of C4N2 in the far and mid infrared domain have shown strong discrepancies with previous results [4]. Following the intensity measurements, a careful analysis of high resolution data has led to the first line lists for C4N2, which gives us the chance to determine precise abundance upper limits of this molecule in Titan's atmosphere.

  5. Vibrational and multinuclear NMR spectra of anionic mercuriomethanes [CH 4-n(HgX) n] n-

    NASA Astrophysics Data System (ADS)

    Breitinger, D. K.; Krumphanzl, U.; Moll, M.

    1990-03-01

    Vibrational spectra of solid sodium sulfitomercuriomethanates Na n[CH 4-n(HgSO 3) n]·nH 2O (2 ≤ and ≤ 4) exhibit high frequencies of the valence vibrations ν as(SO 3) > ν s(SO 3) (average 1057 cm -1) with big differences ν as - ν s (mean 104 cm -1), and ν(HgS) vibrations in the 200 to 230 cm -1 range, thus indicating S-coordinated sulfite ligands. Force field calculations for the ion [C(HgSO 3) 4] 4- yield high force constants K(S-O) = 605 N/m, K(Hg-S) = 258 N/m, and even K(C-Hg) = 181 N/m.- For thiosulfatomercuriomethanates [CH 4-n(HgS 2O 3] n- (1 ≤ n ≤ 4) in aqueous solutions Raman spectra suggest S-coordination with high ν as(SO 3) and ν s(SO 3) (average 1130 cm -1), and low ν(S-S) (˜420 cm -1) frequencies, and strong ν(Hg-S) bands (˜250 cm -1). From 1H, 13C and 199Hg NMR data is concluded that the CHg bond strengths in the series decrease on a lower level than in other mercuriomethanes.- On the whole, the electronic properties of the peripheral ligands X in the mercuriomethanes CH 4-n(HgX) n seem to be more important for the CHg bond strengths than the total charge.

  6. The Radiative Transfer Of CH{sub 4}-N{sub 2} Plasma Arc

    SciTech Connect

    Benallal, R.; Liani, B.

    2008-09-23

    Any physical modelling of a circuit-breaker arc therefore requires an understanding of the radiated energy which is taken into account in the form of a net coefficient. The evaluation of the net emission coefficient is performed by the knowledge of the chemical plasma composition and the resolution of the radiative transfer equation. In this paper, the total radiation which escapes from a CH{sub 4}-N{sub 2} plasma is calculated in the temperature range between 5000 and 30000K on the assumption of a local thermodynamic equilibrium and we have studied the nitrogen effect in the hydrocarbon plasmas.

  7. Critical fields of Fe{sub 4}N/NbN ferromagnetic/superconducting multilayers

    SciTech Connect

    Mattson, J.E.; Potter, C.D.; Conover, M.J.; Sowers, C.H.; Bader, S.D.

    1997-01-01

    Structural, magnetic, and superconducting properties of ferromagnetic/superconducting multilayers of Fe{sub 4}N/NbN are explored for a variety of thickness combinations. The superconducting properties show that 11 {Angstrom} ferromagnetic layers are sufficient to decouple the superconducting layers and to yield anisotropic behavior. The upper critical field data are well described by theory for ferromagnetic/superconducting multilayers. This analysis yields an interfacial parameter which characterizes the electron scattering at the ferromagnetic/superconducting boundary. {copyright} {ital 1997} {ital The American Physical Society}

  8. 4-N,N-Dimethylaminopyridine promoted selective oxidation of methyl aromatics with molecular oxygen.

    PubMed

    Zhang, Zhan; Gao, Jin; Wang, Feng; Xu, Jie

    2012-03-30

    4-N,N-Dimethylaminopyridine (DMAP) as catalyst in combination with benzyl bromide was developed for the selective oxidation of methyl aromatics. DMAP exhibited higher catalytic activity than other pyridine analogues, such as 4-carboxypyridine, 4-cyanopyridine and pyridine. The sp3 hybrid carbon-hydrogen (C-H) bonds of different methyl aromatics were successfully oxygenated with molecular oxygen. The real catalyst is due to the formation of a pyridine onium salt from the bromide and DMAP. The onium salt was well characterized by NMR and the reaction mechanism was discussed.

  9. Diffusion and separation of CH4/N2 in pillared graphene nanomaterials: A molecular dynamics investigation

    NASA Astrophysics Data System (ADS)

    Zhou, Sainan; Lu, Xiaoqing; Wu, Zhonghua; Jin, Dongliang; Guo, Chen; Wang, Maohuai; Wei, Shuxian

    2016-09-01

    Diffusion and separation of CH4/N2 in pillared graphene were investigated by molecular dynamics. The pillared graphene with (6, 6) carbon nanotube (CNT) exhibited the higher diffusion and selectivity of CH4 over N2 than that with (7, 7) CNT due to the cooperative effect of pore topological characteristics and interaction energy. The stronger interaction facilitated CH4 to enter CNT prior to N2, and higher pressure promoted CH4 to pass CNT more easily. The relative concentrations profiles showed that CH4 reached equilibrium state faster than N2 at low pressure. Our results highlight potential use of pillared graphene in gas purification and separation.

  10. Laser pyrolysis fabrication of ferromagnetic gamma'-Fe4N and FeC nanoparticles

    NASA Technical Reports Server (NTRS)

    Grimes, C. A.; Qian, D.; Dickey, E. C.; Allen, J. L.; Eklund, P. C.

    2000-01-01

    Using the laser pyrolysis method, single phase gamma'-Fe4N nanoparticles were prepared by a two step method involving preparation of nanoscale iron oxide and a subsequent gas-solid nitridation reaction. Single phase Fe3C and Fe7C3 could be prepared by laser pyrolysis from Fe(CO)5 and 3C2H4 directly. Characterization techniques such as XRD, TEM and vibrating sample magnetometer were used to measure phase structure, particle size and magnetic properties of these nanoscale nitride and carbide particles. c2000 American Journal of Physics.

  11. Chronic Psychosocial Stress and Negative Feedback Inhibition: Enhanced Hippocampal Glucocorticoid Signaling despite Lower Cytoplasmic GR Expression

    PubMed Central

    Füchsl, Andrea M.; Reber, Stefan O.

    2016-01-01

    Chronic subordinate colony housing (CSC), a pre-clinically validated mouse model for chronic psychosocial stress, results in increased basal and acute stress-induced plasma adrenocorticotropic hormone (ACTH) levels. We assessed CSC effects on hippocampal glucocorticoid (GC) receptor (GR), mineralocorticoid receptor (MR), and FK506 binding protein (FKBP51) expression, acute heterotypic stressor-induced GR translocation, as well as GC effects on gene expression and cell viability in isolated hippocampal cells. CSC mice showed decreased GR mRNA and cytoplasmic protein levels compared with single-housed control (SHC) mice. Basal and acute stress-induced nuclear GR protein expression were comparable between CSC and SHC mice, as were MR and FKBP51 mRNA and/or cytoplasmic protein levels. In vitro the effect of corticosterone (CORT) on hippocampal cell viability and gene transcription was more pronounced in CSC versus SHC mice. In summary, CSC mice show an, if at all, increased hippocampal GC signaling capacity despite lower cytoplasmic GR protein expression, making negative feedback deficits in the hippocampus unlikely to contribute to the increased ACTH drive following CSC. PMID:27057751

  12. Static hyperpolarizability of the van der Waals complex CH(4)-N(2).

    PubMed

    Kalugina, Yulia N; Buldakov, Mikhail A; Cherepanov, Victor N

    2012-12-15

    The static first hyperpolarizability of the van der Waals CH(4)-N(2) complex was calculated. The calculations were carried out in the approximation of the rigid interacting molecules for a broad range of intermolecular separations (R = 6-40 a(0)) and for six configurations at CCSD(T) level of theory using the correlation consistent aug-cc-pVTZ basis set with the basis set superposition error correction. It was shown that the long-range classical approximation, including the terms up to R(-6), is in a good agreement with ab initio calculations for R > 11 a(0). It was found out that for the family of most stable configurations of the complex, the first hyperpolarizability invariants practically do not change (the changes are less than 0.1%). Under forming the stable van der Waals CH(4)-N(2) complex, the intensity and degree of depolarization of the hyper-Rayleigh scattering are noticeable decreased (by ∼10%) to be compared with the free CH(4) and N(2) molecules. PMID:22903865

  13. Evaluation of the Comparative Corrosion Resistance Between AKOT Ti Alloy and Ti Gr 7 Alloy

    SciTech Connect

    Lian, T

    2005-08-01

    In its current design, the drip shields for the high-level nuclear waste containers for the Yucca Mountain repository will be mainly made using Ti Gr 7 (R52400). Ti Gr 7 is a highly corrosion resistant alloy, especially because it contains 0.15% palladium (Pd). The goal of this study was to determine whether an AKOT low-Pd (0.01%) titanium alloy would have a similar corrosion resistance than the more expensive Ti Gr 7 in environments that could be related to the performance of the drip shield. The focus of this testing program was on the susceptibility of the alloys to localized corrosion. Therefore, only artificially creviced specimens were used.

  14. Grüneisen parameter studies on heavy fermion quantum criticality

    NASA Astrophysics Data System (ADS)

    Gegenwart, Philipp

    2016-11-01

    The Grüneisen parameter, experimentally determined from the ratio of thermal expansion to specific heat, quantifies the pressure dependence of characteristic energy scales of matter. It is highly enhanced for Kondo lattice systems, whose properties are strongly dependent on the pressure sensitive antiferromagnetic exchange interaction between f- and conduction electrons. In this review, we focus on the divergence of the Grüneisen parameter and its magnetic analogue, the adiabatic magnetocaloric effect, for heavy-fermion metals near quantum critical points. We compare experimental results with current theoretical models, including the effect of strong geometrical frustration. We also discuss the possibility of using materials with the divergent magnetic Grüneisen parameter for adiabatic demagnetization cooling to very low temperatures.

  15. Complete genome sequence of “Thioalkalivibrio sulfidophilus” HL-EbGr7

    PubMed Central

    Muyzer, Gerard; Sorokin, Dimitry Yu; Mavromatis, Konstantinos; Lapidus, Alla; Clum, Alicia; Ivanova, Natalia; Pati, Amrita; d'Haeseleer, Patrick; Woyke, Tanja; Kyrpides, Nikos C.

    2011-01-01

    “Thioalkalivibrio sulfidophilus” HL-EbGr7 is an obligately chemolithoautotrophic, haloalkaliphilic sulfur-oxidizing bacterium (SOB) belonging to the Gammaproteobacteria. The strain was found to predominate a full-scale bioreactor, removing sulfide from biogas. Here we report the complete genome sequence of strain HL-EbGr7 and its annotation. The genome was sequenced within the Joint Genome Institute Community Sequencing Program, because of its relevance to the sustainable removal of sulfide from bio- and industrial waste gases. PMID:21475584

  16. Investigation of static and cyclic bearing failure mechanisms for GR/EP laminates

    NASA Technical Reports Server (NTRS)

    Walter, R. W.; Tuttle, M. M.

    1992-01-01

    Static, cyclic load (fatigue), and residual strength testing of graphite-epoxy (GR/EP) and aluminum pin bearing joints was completed to study bearing failure mechanisms. Parameters investigated included static strength, failure mode, fatigue life, hole growth, joint stiffness, and residual strength. Comparative evaluation of these results show that the MIL-HDBK-5 convention for the definition of bearing strength can be used for GR/EP materials while maintaining the same, or improved, level of structural integrity shown for metal joints.

  17. Biodegradation and utilization of 4-n-nonylphenol by Aspergillus versicolor as a sole carbon and energy source.

    PubMed

    Krupiński, Mariusz; Janicki, Tomasz; Pałecz, Bartłomiej; Długoński, Jerzy

    2014-09-15

    4-n-Nonylphenol (4-n-NP) is an environmental pollutant with endocrine-disrupting activities that is formed during the degradation of nonylphenol polyethoxylates, which are widely used as surfactants. Utilization of 4-n-NP by the filamentous fungus Aspergillus versicolor as the sole carbon and energy source was investigated. By means of gas chromatography-mass spectrometry, we showed that in the absence of any carbon source other than 4-n-NP in the medium, A. versicolor completely removed the xenobiotic (100 mg L(-1)) after 3 d of cultivation. Moreover, mass spectrometric analysis of intracellular extracts led to the identification of eight intermediates. The mineralization of the xenobiotic in cultures supplemented with 4-n-NP [ring-(14)C(U)] as a growth substrate was also assessed. After 3 d of incubation, approximately 50% of the initially applied radioactivity was recovered in the form of (14)CO2, proving that this xenobiotic was completely metabolized and utilized by A. versicolor as a carbon source. Based on microscopic analysis, A. versicolor is capable of germinating spores under such conditions. To confirm these observations, a microcalorimetric method was used. The results show that even the highest amount of 4-n-NP initiates heat production in the fungal samples, proving that metabolic processes were affected by the use of 4-n-NP as an energetic substrate. PMID:25222932

  18. Induction of mouthpart deformities in Chironomus riparius larvae exposed to 4-n-nonylphenol.

    PubMed

    Meregalli, G; Pluymers, L; Ollevier, F

    2001-01-01

    Chironomid mouthpart deformities have often been associated with sediment contamination and are, therefore, currently used to assess sediment quality. Deformities were only occasionally induced in laboratory bioassays. Mouthpart deformities results from a physiological disturbance during larval molting. In the past few years it has been shown that some chemicals can exert negative effects on both vertebrates and invertebrates at the level of endocrine regulation. As insect molting is hormonally regulated, we wanted to test the hypothesis that deformities are induced due to a hormonal disruption in the developmental process. The aim of the present study was to test whether the endocrine disrupter, 4-n-nonylphenol (4NP), induces mouthpart deformities in chironomids. A laboratory bioassay was performed exposing Chironomus riparius larvae to 10, 50 and 100 micrograms l-1 4NP. Survival of the larvae was not affected by the tested concentrations, but the frequency of mentum deformities increased significantly (P < 0.01) after exposure to 4NP. PMID:11202727

  19. Repairing DNA damage in xeroderma pigmentosum: T4N5 lotion and gene therapy.

    PubMed

    Zahid, Sarwar; Brownell, Isaac

    2008-04-01

    Patients with xeroderma pigmentosum (XP) have defective DNA repair and are at a high risk for cutaneous malignancies. Standard treatments for XP are limited in scope and effectiveness. Understanding the molecular etiology of XP has led to the development of novel therapeutic approaches, including enzyme and gene therapies. One new topical treatment utilizing bacteriophage T4 endonuclease 5 (T4N5) in a liposomal lotion is currently in clinical trials and has received a Fast Track designation from the FDA. Gene therapy for XP, while making leaps in preclinical studies, has been slower to develop due to tactical hurdles, but seems to have much potential for future treatment. If these treatments prove effective in lowering the risk of cancer in patients with XP, they may also be found useful in reducing skin cancers in other at-risk patient populations.

  20. Nitrogen Incorporation in CH4-N2 Photochemical Aerosol Produced by Far Ultraviolet Irradiation

    PubMed Central

    Jimenez, Jose L.; Yung, Yuk L.; Toon, Owen B.; Tolbert, Margaret A.

    2012-01-01

    Abstract Nitrile incorporation into Titan aerosol accompanying hydrocarbon chemistry is thought to be driven by extreme UV wavelengths (λ<120 nm) or magnetospheric electrons in the outer reaches of the atmosphere. Far UV radiation (120–200 nm), which is transmitted down to the stratosphere of Titan, is expected to affect hydrocarbon chemistry only and not initiate the formation of nitrogenated species. We examined the chemical properties of photochemical aerosol produced at far UV wavelengths, using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), which allows for elemental analysis of particle-phase products. Our results show that aerosol formed from CH4/N2 photochemistry contains a surprising amount of nitrogen, up to 16% by mass, a result of photolysis in the far UV. The proportion of nitrogenated organics to hydrocarbon species is shown to be correlated with that of N2 in the irradiated gas. The aerosol mass greatly decreases when N2 is removed, which indicates that N2 plays a major role in aerosol production. Because direct dissociation of N2 is highly improbable given the immeasurably low cross section at the wavelengths studied, the chemical activation of N2 must occur via another pathway. Any chemical activation of N2 at wavelengths >120 nm is presently unaccounted for in atmospheric photochemical models. We suggest that reaction with CH radicals produced from CH4 photolysis may provide a mechanism for incorporating N into the molecular structure of the aerosol. Further work is needed to understand the chemistry involved, as these processes may have significant implications for how we view prebiotic chemistry on early Earth and similar planets. Key Words: Titan—Photochemical aerosol—CH4-N2 photolysis—Far UV—Nitrogen activation. Astrobiology 12, 315–326. PMID:22519972

  1. Uptake of algal carbon and the likely synthesis of an "essential" fatty acid by Uvigerina ex. gr. semiornata (Foraminifera) within the Pakistan margin oxygen minimum zone: evidence from fatty acid biomarker and 13C tracer experiments

    NASA Astrophysics Data System (ADS)

    Larkin, K. E.; Gooday, A. J.; Woulds, C.; Jeffreys, R. M.; Schwartz, M.; Cowie, G.; Whitcraft, C.; Levin, L.; Dick, J. R.; Pond, D. W.

    2014-07-01

    Foraminifera are an important component of benthic communities in oxygen-depleted settings, where they potentially play a significant role in the processing of organic matter. We tracked the uptake of a 13C-labelled algal food source into individual fatty acids in the benthic foraminiferal species Uvigerina ex. gr. semiornata from the Arabian Sea oxygen minimum zone (OMZ). The tracer experiments were conducted on the Pakistan margin during the late/post monsoon period (August-October 2003). A monoculture of the diatom Thalassiosira weisflogii was 13C-labelled and used to simulate a pulse of phytoplankton in two complementary experiments. A lander system was used for in situ incubations at 140 m water depth and for 2.5 days in duration. Shipboard laboratory incubations of cores collected at 140 m incorporated an oxystat system to maintain ambient dissolved oxygen concentrations and were terminated after 5 days. Uptake of diatoms was rapid, with a high incorporation of diatom fatty acids into foraminifera after ~ 2 days in both experiments. Ingestion of the diatom food source was indicated by the increase over time in the quantity of diatom biomarker fatty acids in the foraminifera and by the high percentage of 13C in many of the fatty acids present at the endpoint of both in situ and laboratory-based experiments. These results indicate that gr. semiornata rapidly ingested the diatom food source and that these foraminifera will play an important role in the short-term cycling of organic matter within this OMZ environment. The presence of 18:1(n-7) in the experimental foraminifera suggested that U. ex. gr. semiornata also consumed non-labelled bacterial food items. In addition, levels of 20:4(n-6), a PUFA only present in low amounts in the diatom food, increased dramatically in the foraminifera during both the in situ and shipboard experiments, possibly because it was synthesised de novo. This "essential fatty acid" is often abundant in benthic fauna, yet

  2. Uptake of algal carbon and the synthesis of an "essential" fatty acid by Uvigerina ex. gr. semiornata (Foraminifera) within the Pakistan margin oxygen minimum zone: evidence from fatty acid biomarker and 13C tracer experiments

    NASA Astrophysics Data System (ADS)

    Larkin, K. E.; Gooday, A. J.; Woulds, C.; Jeffreys, R.; Schwartz, M.; Cowie, G.; Whitcraft, C.; Levin, L.; Dick, J. R.; Pond, D. W.

    2014-01-01

    Foraminifera are an important component of benthic communities in oxygen depleted settings, where they potentially play a~significant role in the processing of organic matter. We tracked the uptake of a 13C-labeled algal food source into individual fatty acids in the benthic foraminiferal species, Uvigerina ex. gr. semiornata, from the Arabian Sea oxygen minimum zone (OMZ). The tracer experiments were conducted on the Pakistan Margin during the late/post monsoon period (August-October 2003). A monoculture of the diatom Thalassiosira weisflogii was 13C-labeled and used to simulate a pulse of phytoplankton in two complementary experiments. A lander system was used for in situ incubations at 140 m and for 2.5 days duration, whilst a laboratory incubation used an oxystat system to maintain ambient dissolved oxygen concentrations. These shipboard experiments were terminated after 5 days. Uptake of diatoms was rapid, with high incorporation of diatom fatty acids into foraminifera after ~2 days in both experiments. Ingestion of the diatom food source was indicated by the increase over time in the quantity of diatom biomarker fatty acids in the foraminifera and by the high percentage of 13C in many of the fatty acids present at the endpoint of both in~situ and laboratory-based experiments. These results indicate that U. ex. gr. semiornata rapidly ingested the diatom food source and that this foraminifera will play an important role in the short-term cycling of organic matter within this OMZ environment. The experiments also suggested that U. ex. gr. semiornata consumed non-labeled bacterial food items, particularly bacteria, and synthesised the polyunsaturated fatty acid 20:4(n-6) de novo. 20:4(n-6) is often abundant in benthic fauna yet its origins and function have remained unclear. This study demonstrates that U. ex. gr. semiornata is capable of de novo synthesis of this "essential fatty acid" and is potentially a major source of this dietary nutrient in benthic food

  3. User Manual for the Data-Series Interface of the Gr Application Software

    USGS Publications Warehouse

    Donovan, John M.

    2009-01-01

    This manual describes the data-series interface for the Gr Application software. Basic tasks such as plotting, editing, manipulating, and printing data series are presented. The properties of the various types of data objects and graphical objects used within the application, and the relationships between them also are presented. Descriptions of compatible data-series file formats are provided.

  4. The C.A.M.S. 54 G.R. transatlantic seaplane (French)

    NASA Technical Reports Server (NTRS)

    Ide, John Jay

    1928-01-01

    Tested at the end of March, 1928, the C.A.M.S. 54 G.R. was built for the purpose of crossing the Atlantic from Europe by way of the azores. It has a biplane construction with wings mounted above the hull. It is powered by two new series 500 HP. geared Hispano Suiza V type engines.

  5. Identification of direct targets of plant transcription factors using the GR fusion technique.

    PubMed

    Yamaguchi, Nobutoshi; Winter, Cara M; Wellmer, Frank; Wagner, Doris

    2015-01-01

    The glucocorticoid receptor-dependent activation of plant transcription factors has proven to be a powerful tool for the identification of their direct target genes. In the absence of the synthetic steroid hormone dexamethasone (dex), transcription factors fused to the hormone-binding domain of the glucocorticoid receptor (TF-GR) are held in an inactive state, due to their cytoplasmic localization. This requires physical interaction with the heat shock protein 90 (HSP90) complex. Hormone binding leads to disruption of the interaction between GR and HSP90 and allows TF-GR fusion proteins to enter the nucleus. Once inside the nucleus, they bind to specific DNA sequences and immediately activate or repress expression of their targets. This system is well suited for the identification of direct target genes of transcription factors in plants, as (A) there is little basal protein activity in the absence of dex, (B) steroid application leads to rapid transcription factor activation, (C) no side effects of dex treatment are observed on the physiology of the plant, and (D) secondary effects of transcription factor activity can be eliminated by simultaneous application of an inhibitor of protein biosynthesis, cycloheximide (cyc). In this chapter, we describe detailed protocols for the preparation of plant material, for dex and cyc treatment, for RNA extraction, and for the PCR-based or genome-wide identification of direct targets of transcription factors fused to GR.

  6. Renaturierung von Feuchtgrünland, Auengrünland und mesophilem Grünland

    NASA Astrophysics Data System (ADS)

    Rosenthal, Gert; Hölzel, Norbert

    Grünland stellt in Mitteleuropa fast ausschließlich eine Kulturformation dar, die in der Naturlandschaft abgesehen von extremen Trocken- und Nassstandorten sowie klimatisch ungünstigen Gebieten oberhalb der alpinen Waldgrenze nur kleinflächig vertreten war.Die natürlichen Standorte der heutigen Grünlandarten waren in Mitteleuropa bis in das Atlantikum hinein Wälder oder natürlicherweise waldfreie ökosysteme, wie z.B. Röhricht- und Ufervegetation sowie Biberwiesen in Flussauen, Niedermoore, Randlaggs von Regenmooren, Waldlichtungen oder Lawinenbahnen (Ellenberg 1952, 1996). Die Naturlandschaft der heutigen Grünlandstandorte war durch die natürliche Dynamik der vorherrschenden Waldökosysteme mit ihren Entwicklungsstadien und natürlichen Störungsereignissen (Stürme, überschwemmungen etc.) geprägt. Der Flächenanteil des Grünlandes vergrößerte sich erst durch Beweidung und Heumahd durch den Menschen und seine Haustiere.

  7. NRIP enhances HPV gene expression via interaction with either GR or E2

    SciTech Connect

    Chang, Szu-Wei; Lu, Pei-Yu; Guo, Jih-Huong; Tsai, Tzung-Chieh; Tsao, Yeou-Ping; Chen, Show-Li

    2012-02-05

    We previously identified a gene, nuclear receptor-interaction protein (NRIP), which functions as a transcription cofactor in glucocorticoid receptor (GR) and human papillomavirus E2 (HPV E2)-driven gene expression. Here, we comprehensively evaluated the role of NRIP in HPV-16 gene expression. NRIP acts as a transcription cofactor to enhance GR-regulated HPV-16 gene expression in the presence of hormone. NRIP also can form complex with E2 that caused NRIP-induced HPV gene expression via E2-binding sites in a hormone-independent manner. Furthermore, NRIP can associate with GR and E2 to form tri-protein complex to activate HPV gene expression via GRE, not the E2-binding site, in a hormone-dependent manner. These results indicate that NRIP and GR are viral E2-binding proteins and that NRIP regulates HPV gene expression via GRE and/or E2 binding site in the HPV promoter in a hormone-dependent or independent manner, respectively.

  8. AQ4N: an alkylaminoanthraquinone N-oxide showing bioreductive potential and positive interaction with radiation in vivo.

    PubMed Central

    McKeown, S. R.; Hejmadi, M. V.; McIntyre, I. A.; McAleer, J. J.; Patterson, L. H.

    1995-01-01

    AQ4N (1,4-bis([2-(dimethylamino-N-oxide)ethyl]amino)5,8-dihydroxy- anthracene-9,10-dione) is a novel alkylaminoanthraquinone N-oxide which, on reduction, forms a stable DNA affinic cytotoxic compound AQ4. The in vivo anti-tumour efficacy of AQ4N was investigated in B6D2F1 mice bearing the T50/80 mammary carcinoma. The effect of the drug was evaluated in combination with hypobaric hypoxia and with radiation (single and multiple fractions). Systemic toxicity was assessed by weight loss post treatment. This was low for AQ4N and was less than that obtained with the bioreductive drugs, RSU 1069 (1-[3-aziridinyl-2-hydroxypropyl]-2-nitroimidazole) and SR 4233 (Tirapazamine, 3-amino-1,2,4-benzotriazine-1,4-dioxide). The anti-tumour effect of AQ4N was potentiated in vivo by combination with hypobaric hypoxia with a dose enhancement ratio of 5.1. This is consistent with the proposal that AQ4N was reduced in vivo to AQ4, resulting in enhanced anti-tumour toxicity. When AQ4N (200 mg kg-1) was combined with single dose radiation (12 Gy) the drug was shown to have an additive interaction with radiation. This was obtained even if the drug was administered from 4 days before to 6 h after radiation treatment. Equivalent anti-tumour activity was also shown when both AQ4N (200 mg kg-1) and radiation (5 x 3 Gy) were administered in fractionated schedules. In conclusion, AQ4N shows significant potential as a bioreductive drug for combination with fractionated radiotherapy. PMID:7599069

  9. Induction of human UDP-glucuronosyltransferase 1A1 by cortisol-GR.

    PubMed

    Usui, Toru; Kuno, Takuya; Mizutani, Takaharu

    2006-06-01

    During the course of the study of UGT1A1 induction by bilirubin, we could not detect the induction of the reporter gene (-3174/+14) of human UGT1A1 in HepG2 by bilirubin (Mol. Biol. Rep. 31: 151-158 (2004)). In this report, we show the finding of the induction of the reporter gene of UGT1A1 by cortisol at 1 microM, a major natural cortico-steroid, with human glucocorticoid receptor (GR). RU486 of a typical GR antagonist at 10 microM inhibited the induction by cortisol from 5.9- to 1.8-fold. This result indicates that the induction by cortisol-GR is dependence on ligand-binding. This induction is caused by the UGT reporter gene itself, from the results of noinduction with control vector pGL2 (equal to pGV-C) in the presence of cortisol-GR. We confirmed that the induction of the reporter gene by cortisol is dependent on the position of proximal element (-97/-53) of UGT1A1. From this result, we concluded that the increase of corticosteroid in neonates must induce the elevation of UGT1A1 after birth and prevent jaundice. With the study of induction by corisol, we studied the influence of co-expression of PXR (pregnenolone xenobiotic receptor) with the UGT1A1 reporter gene and we could not find the induction of UGT1A1 expression in the presence of dexamethasone, rifampicin, or pregnenolone 16alpha-carbonitrile of the PXR ligands. These results suggest that the induction of UGT1A1 expression by GR is not mediated by PXR, unlike the induction of CYP3A4 through PXR. PMID:16817017

  10. GR-891: a novel 5-fluorouracil acyclonucleoside prodrug for differentiation therapy in rhabdomyosarcoma cells

    PubMed Central

    Marchal, J A; Prados, J; Melguizo, C; Gómez, J A; Campos, J; Gallo, M A; Espinosa, A; Arena, N; Aránega, A

    1999-01-01

    Differentiation therapy provides an alternative treatment of cancer that overcomes the undesirable effects of classical chemotherapy, i.e. cytotoxicity and resistance to drugs. This new approach to cancer therapy focuses on the development of specific agents designed to selectively engage the process of terminal differentiation, leading to the elimination of tumorigenic cells and recovery of normal cell homeostasis. A series of new anti-cancer pyrimidine acyclonucleoside-like compounds were designed and synthesized by structural modifications of 5-fluorouracil, a drug which causes considerable cell toxicity and morbidity, and we evaluated their applicability for differentiation therapy in human rhabdomyosarcoma cells. We tested the pyrimidine derivative GR-891, (RS)-1-{[3-(2-hydroxyethoxy)-1-isopropoxy]propyl}-5-fluorouracil, an active drug which shows low toxicity in vivo and releases acrolein which is an aldehyde with anti-tumour activity. Both GR-891 and 5-fluorouracil caused time- and dose-dependent growth inhibition in vitro; however, GR-891 showed no cytotoxicity at low doses (22.5 μmol l−1 and 45 μmol l−1) and induced terminal myogenic differentiation in RD cells (a rhabdomyosarcoma cell line) treated for 6 days. Changes in morphological features and in protein organization indicated re-entry in the pathway of muscular maturation. Moreover, GR-891 increased adhesion capability mediated by the expression of fibronectin, and did not induce overexpression of P-glycoprotein, the mdr1 gene product, implicated in multidrug resistance. New acyclonucleoside-like compounds such as GR-891 have important potential advantages over 5-fluorouracil because of their lower toxicity and their ability to induce myogenic differentiation in rhabdomyosarcoma cells. Our results suggest that this drug may be useful for differentiation therapy in this type of tumour. 1999 Cancer Research Campaign PMID:10070873

  11. Cationic motions and phase transitions in [(CH 3) 4N] 2SO 4·4H 2O, [(CH 3) 4N] 2SO 4, and [(CH 3) 4N] 2SeO 4 as studied by 1H NMR, differential thermal analysis, and X-ray powder diffraction techniques

    NASA Astrophysics Data System (ADS)

    Sato, Setsuko; Endo, Midori; Hara, Naoki; Nakamura, Daiyu; Ikeda, Ryuichi

    1995-02-01

    Cationic reorientations have been studied in solid [(CH 3) 4N] 2SO 4·4H 2O, [(CH 3) 4N] 2SO 4, and [(CH 3) 4N] 2SeO 4 by measuring 1H NMR spin-lattice relaxation times, T1. These motions have been discussed in association with the crystal structures and the phase transitions examined by X-ray powder diffraction and differential thermal analysis, respectively. In crystals of [(CH 3) 4N] 2SO 4·4H 2O, there are two kinds of cations distorted from regular tetrahedra. T1 is calculated according to the interpretation that two T1 minima are due to the two inequivalent (NH 3) 4N + ions reorienting at different frequencies. The result shows that at the phase transition temperatures, the correlation times to those cationic reorientations are very different from each other in this compound in contrast with (NH 4) 2SO 4 and [(CH 3) 4N] 2CdX 4 (X = Cl and Br). For the sulfate and selenate, there is a single kind of cation which can be considered tetrahedral, and the phase transitions occur in the temperature region where the narrowing of the resonance line owing to the overall cationic reorientations starts.

  12. Maternal betaine supplementation during gestation modifies hippocampal expression of GR and its regulatory miRNAs in neonatal piglets

    PubMed Central

    SUN, Qinwei; LI, Xi; JIA, Yimin; PAN, Shifeng; LI, Runsheng; YANG, Xiaojing; ZHAO, Ruqian

    2016-01-01

    Methyl donor nutrients are critical for embryonic development of brain. Hippocampus is the most susceptible brain region to various factors including prenatal supply of methyl donors. Glucocorticoid receptor (GR) expressed in hippocampus is involved in the regulation of energy homeostasis and stress sensitivity. Hippocampal GR expression is highly susceptible to epigenetic regulation, yet the effect of maternal methyl donor supplementation on epigenetic regulation of GR transcription in offspring hippocampus remains unclear. In this study, we fed sows with betaine (3 g/kg) throughout the gestation and analyzed the hippocampal expression of GR mRNA and its variants, as well as the CpG methylation status of the promoter and the microRNAs predicted to target 3’ UTR of porcine GR gene in neonatal piglets. Total GR mRNA (P<0.01) and its variants GR 1-4 (P<0.05) and 1-9,10 (P<0.01), were significantly higher in the hippocampus of betaine-treated piglets, while the content of GR protein was not significantly changed. The CpGs located in the –1650 ~ –1515 segment of GR gene were hypermethylated (P<0.05). The hippocampal expression of miR-130b (P<0.05), miR-181a (P<0.05) and miR-181d (P<0.01) was significantly up-regulated. The targeting efficacy of miR-130b and miR-181d was validated in vitro using dual-luciferase reporter assay system. Our results demonstrate that maternal betaine supplementation during gestation enhances GR mRNA expression in offspring hippocampus, which involves alterations in miRNAs expression. PMID:26875838

  13. The role of Gr-1+ cells and tumour necrosis factor-α signalling during Clostridium difficile colitis in mice

    PubMed Central

    McDermott, Andrew J; Higdon, Kathryn E; Muraglia, Ryan; Erb-Downward, John R; Falkowski, Nicole R; McDonald, Roderick A; Young, Vincent B; Huffnagle, Gary B

    2015-01-01

    The host response to Clostridium difficile infection in antibiotic-treated mice is characterized by robust recruitment of Gr-1+ cells, increased expression of inflammatory cytokines including tumour necrosis factor-α (TNF-α), and the development of severe epithelial damage. To investigate the role of Gr-1+ cells and TNF-α during C. difficile colitis, we treated infected mice with monoclonal antibodies against Gr-1 or TNF-α. Mice were challenged with vegetative cells of C. difficile strain VPI 10463 following treatment with the third-generation cephalosporin ceftriaxone. Ceftriaxone treatment alone was associated with significant changes in cytokine expression within the colonic mucosa but not overt inflammatory histopathological changes. In comparison, C. difficile infection following ceftriaxone treatment was associated with increased expression of inflammatory cytokines and chemokines including Cxcl1, Cxcl2, Il1b, Il17f and Tnfa, as well as robust recruitment of Ly6CMid Gr-1High neutrophils and Ly6CHigh Gr-1Mid monocytes and the development of severe colonic histopathology. Anti-Gr-1 antibody treatment resulted in effective depletion of both Ly6CMid Gr-1High neutrophils and Ly6CHigh Gr-1Mid monocytes: however, we observed no protection from the development of severe pathology or reduction in expression of the pro-inflammatory cytokines Il1b, Il6, Il33 and Tnfa following anti-Gr-1 treatment. By contrast, anti-TNF-α treatment did not affect Gr-1+ cell recruitment, but was associated with increased expression of Il6 and Il1b. Additionally, Ffar2, Ffar3, Tslp, Tff and Ang4 expression was significantly reduced in anti-TNF-α-treated animals, in association with marked intestinal histopathology. These studies raise the possibility that TNF-α may play a role in restraining inflammation and protecting the epithelium during C. difficile infection. PMID:25399934

  14. Spherically symmetric solutions of a (4 + n)-dimensional Einstein Yang Mills model with cosmological constant

    NASA Astrophysics Data System (ADS)

    Brihaye, Yves; Hartmann, Betti

    2005-01-01

    We construct solutions of an Einstein Yang Mills system including a cosmological constant in 4 + n spacetime dimensions, where the n-dimensional manifold associated with the extra dimensions is taken to be Ricci flat. Assuming the matter and metric fields to be independent of the n extra coordinates, a spherical symmetric ansatz for the fields leads to a set of coupled ordinary differential equations. We find that for n > 1 only solutions with either one non-zero Higgs field or with all Higgs fields constant and zero gauge field function (corresponding to a Wu Yang-type ansatz) exist. We give the analytic solutions available in this model. These are 'embedded' Abelian solutions with a diverging size of the manifold associated with the extra n dimensions. Depending on the choice of parameters, these latter solutions either represent naked singularities or they possess a single horizon. We also present solutions of the effective four-dimensional Einstein Yang Mills Higgs-dilaton model, where the higher-dimensional cosmological constant induces a Liouville-type potential. The solutions are non-Abelian solutions with diverging Higgs fields, which exist only up to a maximal value of the cosmological constant.

  15. Structure, conformation and hydrogen bonding of 4-( N-methylpiperidinium)-butyric acid bromide

    NASA Astrophysics Data System (ADS)

    Dega-Szafran, Z.; Dulewicz, E.; Szafran, M.; Thaimattam, R.; Jaskolski, M.

    2007-02-01

    A 1:1 complex between 4-( N-methylpiperidinium)-butyrate inner salt (betaine) and hydrobromide, MPBUH·Br, has been characterized by single crystal X-ray analysis. The crystals are monoclinic, space group P2 1/c, with a = 8.284(1), b = 10.369(1), c = 13.809(2) Å, β = 92.26(1)°. The piperidine ring adopts a chair conformation with the (CH 2) 3COOH substituent in the axial and the CH 3 group in the equatorial positions. In the crystal, the Br - anion is engaged in a medium-strong hydrogen bond with the COOH group (O sbnd H⋯Br - = 3.141(1) Å), N +⋯Br - electrostatic interactions and in several C sbnd H⋯Br - contacts with the aliphatic groups forming a cavity in which it is enclosed. Three conformers ( 2- 4) were optimized by the B3LYP/6-31G (d, p) level of theory. The most stable is conformer 4 with the (CH 2) 3COOH substituent in the equatorial position and the CH 3 group in the axial position. The stability of the investigated conformers is controlled by electrostatic interactions between the oppositely charged groups. The FTIR spectrum of MPBUH·Br shows a strong band at 2941 cm -1 due to νOH and the νC dbnd O band at 1712 cm -1.

  16. Purification and characterization of 4-N-trimethylamino-1-butanol dehydrogenase from Fusarium merismoides var. acetilereum.

    PubMed

    Fujimitsu, Hiroshi; Taniyama, Yuko; Tajima, Sae; Mohamed Ahmed, Isam A; Arima, Jiro; Mori, Nobuhiro

    2016-09-01

    From investigation of 60 filamentous fungi, we identified Fusarium merismoides var. acetilereum, which uses 4-N-trimethylamino-1-butanol (TMA-butanol) as the sole source of carbon and nitrogen. The fungus produced NAD(+)-dependent TMA-butanol dehydrogenase (DH) when it was cultivated in medium containing TMA-butanol. The enzyme showed molecular mass of 40 kDa by SDS-PAGE and 160 kDa by gel filtration, suggesting that it is a homotetramer. TMA-butanol DH is stable at pH 7.5-9.0. It exhibits moderate stability with respect to temperature (up to 30 °C). Additionally, it has optimum activity at 45 °C and at pH 9.5. The enzyme has broad specificity to various alkyl alcohols and amino alkyl alcohols, and the carbon chains of which are longer than butanol. Moreover, the activity is strongly inhibited by oxidizing agents, carbonyl and thiol modulators, and chelating agents. This report is the first study examining TMA-butanol DH from eukaryotic microbes. PMID:27121905

  17. Can Moral Hazard Be Resolved by Common-Knowledge in S4n-Knowledge?

    NASA Astrophysics Data System (ADS)

    Matsuhisa, Takashi

    This article investigates the relationship between common-knowledge and agreement in multi-agent system, and to apply the agreement result by common-knowledge to the principal-agent model under non-partition information. We treat the two problems: (1) how we capture the fact that the agents agree on an event or they get consensus on it from epistemic point of view, and (2) how the agreement theorem will be able to make progress to settle a moral hazard problem in the principal-agents model under non-partition information. We shall propose a solution program for the moral hazard in the principal-agents model under non-partition information by common-knowledge. Let us start that the agents have the knowledge structure induced from a reflexive and transitive relation associated with the multi-modal logic S4n. Each agent obtains the membership value of an event under his/her private information, so he/she considers the event as fuzzy set. Specifically consider the situation that the agents commonly know all membership values of the other agents. In this circumstance we shall show the agreement theorem that consensus on the membership values among all agents can still be guaranteed. Furthermore, under certain assumptions we shall show that the moral hazard can be resolved in the principal-agent model when all the expected marginal costs are common-knowledge among the principal and agents.

  18. Cation-Cation Interactions in [(UO2)2(OH)n](4-n) Complexes

    SciTech Connect

    Odoh, Samuel O.; Govind, Niranjan; Schreckenbach, Georg; De Jong, Wibe A.

    2013-10-07

    The structures and bonding of gas-phase [(UO2)2(OH)n]4-n (n=2-6) complexes have been studied using density functional theory (DFT), MP2 and CCSD(T) methods with particular emphasis on ground state structures featuring cation-cation interactions (CCIs) between the uranyl groups. An interesting trend is observed in the stabilities of members of this series of complexes. The structures of [(UO2)2(OH)2]2+, [(UO2)2(OH)4] and [(UO2)2(OH)6]2- featuring CCIs are found at higher energies (by 3-20 kcal/mol) in comparison to their conventional μ2-dihydroxo structures. In contrast, the CCI structures of [(UO2)2(OH)3]+ and [(UO2)2(OH)5]- are respectively almost degenerate with and lower in energy than the structures with the μ2-dihydroxo format. The origin of this trend lies in the ‘symmetry’-based need to balance the coordination numbers and effective atomic charges of each uranium center. The calculated IR vibrational frequencies provide signature probes that can be used in differentiating the lowenergy structures and in experimentally confirming the existence of the structures featuring CCIs. Analysis of the bonding in the structures of [(UO2)2(OH)3]+ and [(UO2)2(OH)5]- shows that the CCIs and bridging hydroxo between the dioxo-uranium units are mainly electrostatic in nature.

  19. Early Events in the Nonadiabatic Relaxation Dynamics of 4-(N,N-Dimethylamino)benzonitrile.

    PubMed

    Kochman, Michał A; Tajti, Attila; Morrison, Carole A; Miller, R J Dwayne

    2015-03-10

    4-(N,N-Dimethylamino)benzonitrile (DMABN) is the archetypal system for dual fluorescence. Several past studies, both experimental and theoretical, have examined the mechanism of its relaxation in the gas phase following photoexcitation to the S2 state, without converging to a single description. In this contribution, we report first-principles simulations of the early events involved in this process performed using the nonadiabatic trajectory surface hopping (TSH) approach in combination with the ADC(2) electronic structure method. ADC(2) is verified to reproduce the ground- and excited-state structures of DMABN in reasonably close agreement with previous theoretical benchmarks. The TSH simulations predict that internal conversion from the S2 state to the S1 takes place as early as 8.5 fs, on average, after the initial photoexcitation, and with no significant torsion of the dimethylamino group relative to the aromatic ring. As evidenced by supporting EOM-CCSD calculations, the population transfer from S2 to S1 can be attributed to the skeletal deformation modes of the aromatic ring and the stretching of the ring-dimethylamino nitrogen bond. The non- or slightly twisted locally excited structure is the predominant product of the internal conversion, and the twisted intramolecular charge transfer structure is formed through equilibration with the locally excited structure with no change of adiabatic state. These findings point toward a new interpretation of data from previous time-resolved experiments. PMID:26579762

  20. Structural and biological evaluation of some metal complexes of vanillin-4N-(2-pyridyl) thiosemicarbazone

    NASA Astrophysics Data System (ADS)

    Yousef, T. A.; Abu El-Reash, G. M.; Al-Jahdali, M.; El-Rakhawy, El-Bastawesy R.

    2013-12-01

    The synthesis and characterization of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) and U(VI)O2 complexes of vanillin-4N-(2-pyridyl) thiosemicarbazone (H2PVT) are reported. Theoretical calculations have been performed to obtain IR spectra of ligand and its complexes using AM1, Zindo/1, MM+ and PM3, methods. The Schiff base and its metal complexes have been screened for antibacterial Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Staphylococcus saprophyticus. H2VPT shows no apparent digestion effect on the egg albumin while Mn(II), Hg(II) and Cu(II) complexes exhibited a considerable digestion effect following the order Cu(II) > Mn(II) > Hg(II). Moreover, Ni(II) and Co(II) complexes revealed strong digestion effect. Fe(II), Mn(II), Cu(II), Zn(II) and Ni(II) acted as metal co- SOD enzyme factors, which are located in different compartments of the cell.

  1. Transport Properties of a Rarefied Ch4-N2 Gas Mixture

    NASA Astrophysics Data System (ADS)

    Fokin, L. R.; Kalashnikov, A. N.

    2016-01-01

    The area of application of the rarefied neutral methane-nitrogen gas mixture is considered. Experimental data on the transport properties of this mixture and its components were analyzed and generalized on the basis of molecular-kinetic theory relations with the use of the potentials of pair uniform and cross interactions of CH4 and N2 molecules. The parameters of three spherical symmetric three-parameter m-6 Lennard-Jones interaction potentials with a repulsive branch of varying rigidity were determined with the use of the nonlinear weight method of least squares. Tables of reference data on the viscosity of the indicated mixture and the coefficients of interdiffusion of its components were calculated for the concentration range 0-1 at temperatures 100-1150 K. Estimates of the confidential errors in determining the properties of this mixture have been made with the use of the error matrix of parameters of the indicated potentials. The results of calculations were compared with the corresponding reference data obtained earlier for the CH4-N2 gas mixture.

  2. gr/gr-DAZ2-DAZ4-CDY1b deletion is a high-risk factor for male infertility in Tunisian population.

    PubMed

    Ghorbel, Myriam; Baklouti-Gargouri, Siwar; Keskes, Rim; Chakroun, Nozha; Sellami, Afifa; Fakhfakh, Faiza; Ammar-Keskes, Leila

    2016-10-30

    The azoospermia factor c (AZFc) region harbors multi-copy genes that are expressed in the testis. Deletions of this region lead to reduced copy numbers of these genes. In this present study we aimed to determine the frequency of AZFc subdeletion in infertile and fertile men from Tunisia and to identify whether deletions of DAZ and CDY1 gene copies are deleterious on spermatogenesis and on semen quality. We studied a group of 241 infertile men and 115 fertile healthy males using a sequence tagged site (STS)±method. To gain insight into the molecular basis of the heterogeneous phenotype observed in men with the deletion we defined the type of DAZ and CDY1 genes deleted. We reported in the present study and for the first time a new type of AZFc deletion (gr/gr-DAZ2-DAZ4-CDY1b) and hypothesis that this new deletion is the result of two successive events. We also demonstrated that this deletion constitutes a relative high-risk factor for male infertility in Tunisian population. PMID:27457284

  3. Balloon Angioplasty - The Legacy of Andreas Grüntzig, M.D. (1939-1985).

    PubMed

    Barton, Matthias; Grüntzig, Johannes; Husmann, Marc; Rösch, Josef

    2014-01-01

    In 1974, at the Medical Policlinic of the University of Zürich, German-born physician-scientist Andreas Grüntzig (1939-1985) for the first time applied a balloon-tipped catheter to re-open a severely stenosed femoral artery, a procedure, which he initially called "percutaneous transluminal dilatation". Balloon angioplasty as a therapy of atherosclerotic vascular disease, for which Grüntzig and Charles T. Dotter (1920-1985) received a nomination for the Nobel Prize in Physiology or Medicine in 1978, became one of the most successful examples of translational medicine in the twentieth century. Known today as percutaneous transluminal angioplasty (PTA) in peripheral arteries or percutaneous transluminal coronary angioplasty (PTCA) or percutaneous coronary intervention (PCI) in coronary arteries, balloon angioplasty has become the method of choice to treat patients with acute myocardial infarction or occluded leg arteries. On the occasion of the 40(th) anniversary of balloon angioplasty, we summarize Grüntzig's life and career in Germany, Switzerland, and the United States and also review the developments in vascular medicine from the 1890s to the 1980s, including Dotter's first accidental angioplasty in 1963. The work of pioneers of catheterization, including Pedro L. Fariñas in Cuba, André F. Cournand in France, Werner Forssmann, Werner Porstmann and Eberhard Zeitler in Germany, António Egas Moniz and Reynaldo dos Santos in Portugal, Sven-Ivar Seldinger in Sweden, and Barney Brooks, Thomas J. Fogarty, Melvin P. Judkins, Richard K. Myler, Dickinson W. Richards, and F. Mason Sones in the United States, is discussed. We also present quotes by Grüntzig and excerpts from his unfinished autobiography, statements of Grüntzig's former colleagues and contemporary witnesses, and have included hitherto unpublished historic photographs and links to archive recordings and historic materials. This year, on June 25, 2014, Andreas Grüntzig would have celebrated his 75(th

  4. Balloon Angioplasty - The Legacy of Andreas Grüntzig, M.D. (1939-1985).

    PubMed

    Barton, Matthias; Grüntzig, Johannes; Husmann, Marc; Rösch, Josef

    2014-01-01

    In 1974, at the Medical Policlinic of the University of Zürich, German-born physician-scientist Andreas Grüntzig (1939-1985) for the first time applied a balloon-tipped catheter to re-open a severely stenosed femoral artery, a procedure, which he initially called "percutaneous transluminal dilatation". Balloon angioplasty as a therapy of atherosclerotic vascular disease, for which Grüntzig and Charles T. Dotter (1920-1985) received a nomination for the Nobel Prize in Physiology or Medicine in 1978, became one of the most successful examples of translational medicine in the twentieth century. Known today as percutaneous transluminal angioplasty (PTA) in peripheral arteries or percutaneous transluminal coronary angioplasty (PTCA) or percutaneous coronary intervention (PCI) in coronary arteries, balloon angioplasty has become the method of choice to treat patients with acute myocardial infarction or occluded leg arteries. On the occasion of the 40(th) anniversary of balloon angioplasty, we summarize Grüntzig's life and career in Germany, Switzerland, and the United States and also review the developments in vascular medicine from the 1890s to the 1980s, including Dotter's first accidental angioplasty in 1963. The work of pioneers of catheterization, including Pedro L. Fariñas in Cuba, André F. Cournand in France, Werner Forssmann, Werner Porstmann and Eberhard Zeitler in Germany, António Egas Moniz and Reynaldo dos Santos in Portugal, Sven-Ivar Seldinger in Sweden, and Barney Brooks, Thomas J. Fogarty, Melvin P. Judkins, Richard K. Myler, Dickinson W. Richards, and F. Mason Sones in the United States, is discussed. We also present quotes by Grüntzig and excerpts from his unfinished autobiography, statements of Grüntzig's former colleagues and contemporary witnesses, and have included hitherto unpublished historic photographs and links to archive recordings and historic materials. This year, on June 25, 2014, Andreas Grüntzig would have celebrated his 75(th

  5. The diverse electronic properties of C4N3 monolayer under biaxial compressive strain: a theoretical study

    NASA Astrophysics Data System (ADS)

    Wu, Haiping; Liu, Yuzhen; Kan, Erjun; Ma, Yanming; Xu, Wenjie; Li, Jie; Yan, Meichen; Lu, Ruifeng; Wei, Jianfeng; Qian, Yan

    2016-07-01

    Because of the observation of half-metallicity in graphitic carbon nitride C4N3 (g-C4N3), extensive research has recently been focused on this compound. Using density-functional calculations, herein diverse electronic properties of g-C4N3 were engineered by applying biaxial compressive strain. The calculated results demonstrate that g-C4N3 preserves ferromagnetic half-metallicity when the strain is lower than  -2%, accompanied by a decrease of the half-metallic gap. When the compressive strain ranges from  -5 to  -3%, the compound turns into nonmagnetic metal. By increasing the strain on the end, it becomes a nonmagnetic semiconductor. Further investigations show that all nonmagnetic semiconductors possess a direct band gap with a value of around 1.6 eV. This fact indicates that g-C4N3 can be applied in spintronic or photovoltaic fields under a strain environment.

  6. The diverse electronic properties of C4N3 monolayer under biaxial compressive strain: a theoretical study

    NASA Astrophysics Data System (ADS)

    Wu, Haiping; Liu, Yuzhen; Kan, Erjun; Ma, Yanming; Xu, Wenjie; Li, Jie; Yan, Meichen; Lu, Ruifeng; Wei, Jianfeng; Qian, Yan

    2016-07-01

    Because of the observation of half-metallicity in graphitic carbon nitride C4N3 (g-C4N3), extensive research has recently been focused on this compound. Using density-functional calculations, herein diverse electronic properties of g-C4N3 were engineered by applying biaxial compressive strain. The calculated results demonstrate that g-C4N3 preserves ferromagnetic half-metallicity when the strain is lower than  ‑2%, accompanied by a decrease of the half-metallic gap. When the compressive strain ranges from  ‑5 to  ‑3%, the compound turns into nonmagnetic metal. By increasing the strain on the end, it becomes a nonmagnetic semiconductor. Further investigations show that all nonmagnetic semiconductors possess a direct band gap with a value of around 1.6 eV. This fact indicates that g-C4N3 can be applied in spintronic or photovoltaic fields under a strain environment.

  7. Propagation of Flexural Mode AE Signals in GR/EP Composite Plates

    NASA Technical Reports Server (NTRS)

    Prosser, W. H.; Gorman, M. R.

    1992-01-01

    It has been documented that AE signals propagate in thin plates as extensional and flexural plate modes. This was demonstrated using simulated AE sources (pencil lead breaks) by Gorman on thin aluminum and gr/ep composite plates and by Gorman and Prosser on thin aluminum plates. A typical signal from a pencil lead break source which identifies these two modes is shown. AE signals from transverse matrix cracking sources in gr/ep composite plates were also shown to propagate as plate modes by Gorman and Ziola. Smith showed that crack growth events in thin aluminum plates under spectrum fatigue loading produced signals that propagated as plate modes. Additionally, Prosser et al. showed that AE signals propagated as plate modes in a thin walled composite tube.

  8. Nitrogen Incorporation in CH4-N2 Photochemical Aerosol Produced by Far UV Irradiation

    NASA Technical Reports Server (NTRS)

    Trainer, Melissa G.; Jimenez, Jose L.; Yung, Yuk L.; Toon, Owen B.; Tolbert, Margaret A.

    2012-01-01

    Nitrile incorporation into Titan aerosol accompanying hydrocarbon chemistry is thought to be driven by extreme UV wavelengths (lambda < 120 nm) or magnetospheric electrons in the outer reaches of the atmosphere. Far UV radiation (120 - 200 nm), which is transmitted down to the stratosphere of Titan, is expected to affect hydrocarbon chemistry only and not initiate the formation of nitrogenated species. We have examined the chemical properties of photochemical aerosol produced at far UV wavelengths using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS), which allows for elemental analysis of particle-phase products. Our results show that aerosol formed from CH4/N2 photochemistry contains a surprising amount of nitrogen, up to 16% by mass, a result of photolysis in the far UV. The proportion of nitrogenated organics to hydrocarbon species is shown to be correlated with that of N2 in the irradiated gas. The aerosol mass greatly decreases when N2 is removed, indicating that N2 plays a major role in aerosol production. Because direct dissociation of N2 is highly improbable given the immeasurably low cross-section at the wavelengths studied, the chemical activation of N2 must occur via another pathway. Any chemical activation of N2 at wavelengths > 120 nm is presently unaccounted for in atmospheric photochemical models. We suggest that reaction with CH radicals produced from CH4 photolysis may provide a mechanism for incorporating N into the molecular structure of the aerosol. Further work is needed to understand the chemistry involved, as these processes may have significant implications for prebiotic chemistry on the early Earth and similar planets.

  9. Effects of Picoxystrobin and 4-n-Nonylphenol on Soil Microbial Community Structure and Respiration Activity

    PubMed Central

    Stenrød, Marianne; Klemsdal, Sonja S.; Norli, Hans Ragnar; Eklo, Ole Martin

    2013-01-01

    There is widespread use of chemical amendments to meet the demands for increased productivity in agriculture. Potentially toxic compounds, single or in mixtures, are added to the soil medium on a regular basis, while the ecotoxicological risk assessment procedures mainly follow a chemical by chemical approach. Picoxystrobin is a fungicide that has caused concern due to studies showing potentially detrimental effects to soil fauna (earthworms), while negative effects on soil microbial activities (nitrification, respiration) are shown to be transient. Potential mixture situations with nonylphenol, a chemical frequently occurring as a contaminant in sewage sludge used for land application, infer a need to explore whether these chemicals in mixture could alter the potential effects of picoxystrobin on the soil microflora. The main objective of this study was to assess the effects of picoxystrobin and nonylphenol, as single chemicals and mixtures, on soil microbial community structure and respiration activity in an agricultural sandy loam. Effects of the chemicals were assessed through measurements of soil microbial respiration activity and soil bacterial and fungal community structure fingerprints, together with a degradation study of the chemicals, through a 70 d incubation period. Picoxystrobin caused a decrease in the respiration activity, while 4-n-nonylphenol caused an increase in respiration activity concurring with a rapid degradation of the substance. Community structure fingerprints were also affected, but these results could not be directly interpreted in terms of positive or negative effects, and were indicated to be transient. Treatment with the chemicals in mixture caused less evident changes and indicated antagonistic effects between the chemicals in soil. In conclusion, the results imply that the application of the fungicide picoxystrobin and nonylphenol from sewage sludge application to agricultural soil in environmentally relevant concentrations, as

  10. Transcriptional regulation of human paraoxonase 1 by PXR and GR in human hepatoma cells.

    PubMed

    Ponce-Ruiz, N; Rojas-García, A E; Barrón-Vivanco, B S; Elizondo, G; Bernal-Hernández, Y Y; Mejía-García, A; Medina-Díaz, I M

    2015-12-25

    Human paraoxonase 1 (PON1) is A-esterase synthesized in the liver and secreted into the plasma, where it associates with HDL. PON1 acts as an antioxidant preventing lipid oxidation and detoxifies a wide range of substrates, including organophosphate compounds. The variability of PON1 (enzyme activity/serum levels) has been attributed to internal and external factors. However, the molecular mechanisms involved in the transcriptional regulation of PON1 have not been well-studied. The aim of this study was to evaluate and characterize the transcriptional activation of PON1 by nuclear receptors (NR) in human hepatoma cells. In silico analysis was performed on the promoter region of PON1 to determine the response elements of NR. Real-time PCR was used to evaluate the effect of specific NR ligands on the mRNA levels of genes regulated by NR and PON1. The results indicated that NR response elements had 95% homology to pregnenolone (PXR), glucocorticoids (GR), retinoic acid (RXR) and peroxisomes proliferator-activated receptor alpha (PPARα). Treatments with Dexamethasone (GR ligand), Rifampicin (PXR ligand) and TCDD (AhR ligand) increased the mRNA levels of PON1 at 24 and 48 h. We showed that the activation of GR by Dexamethasone results in PON1 gene induction accompanied by an increase in activity levels. In conclusion, these results demonstrate that GR regulates PON1 gene transcription through directly binding to NR response elements at -95 to -628 bp of the PON1 promoter. This study suggests new molecular mechanisms for the transcriptional regulation of PON1 through a process involving the activation of PXR.

  11. Transcriptional regulation of human paraoxonase 1 by PXR and GR in human hepatoma cells.

    PubMed

    Ponce-Ruiz, N; Rojas-García, A E; Barrón-Vivanco, B S; Elizondo, G; Bernal-Hernández, Y Y; Mejía-García, A; Medina-Díaz, I M

    2015-12-25

    Human paraoxonase 1 (PON1) is A-esterase synthesized in the liver and secreted into the plasma, where it associates with HDL. PON1 acts as an antioxidant preventing lipid oxidation and detoxifies a wide range of substrates, including organophosphate compounds. The variability of PON1 (enzyme activity/serum levels) has been attributed to internal and external factors. However, the molecular mechanisms involved in the transcriptional regulation of PON1 have not been well-studied. The aim of this study was to evaluate and characterize the transcriptional activation of PON1 by nuclear receptors (NR) in human hepatoma cells. In silico analysis was performed on the promoter region of PON1 to determine the response elements of NR. Real-time PCR was used to evaluate the effect of specific NR ligands on the mRNA levels of genes regulated by NR and PON1. The results indicated that NR response elements had 95% homology to pregnenolone (PXR), glucocorticoids (GR), retinoic acid (RXR) and peroxisomes proliferator-activated receptor alpha (PPARα). Treatments with Dexamethasone (GR ligand), Rifampicin (PXR ligand) and TCDD (AhR ligand) increased the mRNA levels of PON1 at 24 and 48 h. We showed that the activation of GR by Dexamethasone results in PON1 gene induction accompanied by an increase in activity levels. In conclusion, these results demonstrate that GR regulates PON1 gene transcription through directly binding to NR response elements at -95 to -628 bp of the PON1 promoter. This study suggests new molecular mechanisms for the transcriptional regulation of PON1 through a process involving the activation of PXR. PMID:26434531

  12. Optical observations of the type Ic supernova 2007gr in NGC 1058

    SciTech Connect

    Chen, Juncheng; Wang, Xiaofeng; Li, Junzheng; Ganeshalingam, Mohan; Silverman, Jeffrey M.; Filippenko, Alexei V.; Li, Weidong; Chornock, Ryan; Steele, Thea E-mail: wang_xf@mail.tsinghua.edu.cn

    2014-08-01

    We present extensive optical observations of the normal Type Ic supernova (SN) 2007gr, spanning from about one week before maximum light to more than one year thereafter. The optical light and color curves of SN 2007gr are very similar to those of the broad-lined Type Ic SN 2002ap, but the spectra show remarkable differences. The optical spectra of SN 2007gr are characterized by unusually narrow lines, prominent carbon lines, and slow evolution of the line velocity after maximum light. The earliest spectrum (taken at t = –8 days) shows a possible signature of helium (He I λ5876 at a velocity of ∼19,000 km s{sup –1}). Moreover, the larger intensity ratio of the [O I] λ6300 and λ6364 lines inferred from the early nebular spectra implies a lower opacity of the ejecta shortly after the explosion. These results indicate that SN 2007gr perhaps underwent a less energetic explosion of a smaller-mass Wolf-Rayet star (∼8-9 M{sub ☉}) in a binary system, as favored by an analysis of the progenitor environment through pre-explosion and post-explosion Hubble Space Telescope images. In the nebular spectra, asymmetric double-peaked profiles can be seen in the [O I] λ6300 and Mg I] λ4571 lines. We suggest that the two peaks are contributed by the blueshifted and rest-frame components. The similarity in velocity structure and the different evolution of the strength of the two components favor an aspherical explosion with the ejecta distributed in a torus or disk-like geometry, but inside the ejecta the O and Mg have different distributions.

  13. Optical Observations of the Type Ic Supernova 2007gr in NGC 1058

    NASA Astrophysics Data System (ADS)

    Chen, Juncheng; Wang, Xiaofeng; Ganeshalingam, Mohan; Silverman, Jeffrey M.; Filippenko, Alexei V.; Li, Weidong; Chornock, Ryan; Li, Junzheng; Steele, Thea

    2014-08-01

    We present extensive optical observations of the normal Type Ic supernova (SN) 2007gr, spanning from about one week before maximum light to more than one year thereafter. The optical light and color curves of SN 2007gr are very similar to those of the broad-lined Type Ic SN 2002ap, but the spectra show remarkable differences. The optical spectra of SN 2007gr are characterized by unusually narrow lines, prominent carbon lines, and slow evolution of the line velocity after maximum light. The earliest spectrum (taken at t = -8 days) shows a possible signature of helium (He I λ5876 at a velocity of ~19,000 km s-1). Moreover, the larger intensity ratio of the [O I] λ6300 and λ6364 lines inferred from the early nebular spectra implies a lower opacity of the ejecta shortly after the explosion. These results indicate that SN 2007gr perhaps underwent a less energetic explosion of a smaller-mass Wolf-Rayet star (~8-9 M ⊙) in a binary system, as favored by an analysis of the progenitor environment through pre-explosion and post-explosion Hubble Space Telescope images. In the nebular spectra, asymmetric double-peaked profiles can be seen in the [O I] λ6300 and Mg I] λ4571 lines. We suggest that the two peaks are contributed by the blueshifted and rest-frame components. The similarity in velocity structure and the different evolution of the strength of the two components favor an aspherical explosion with the ejecta distributed in a torus or disk-like geometry, but inside the ejecta the O and Mg have different distributions.

  14. Characterization of the theta replication plasmid pGR7 from Acetobacter aceti CCM 3610.

    PubMed

    Grones, Peter; Grones, Jozef

    2012-07-01

    A cryptic plasmid of Acetobacter aceti CCM 3610, designated pGR7, was sequenced and characterized. It is a 2446-bp circular molecule with a G + C content of 30%, which is unusual when compared to the already known plasmids isolated from Acetobacter genera. Sequence analysis of pGR7 revealed three putative open reading frames (ORFs). ORF1 displays low similarity with other Acetobacter plasmid replication proteins. The other two ORFs show similarities only to hypothetical proteins and do not encode any important protein. The replication module comprises a DnaA box-like sequence, indirect repeats, a potential prokaryotic promoter and the rep gene. The rep module organization is similar to that found in other theta-replicating plasmids from acetic acid bacteria that stably maintain in both Acetobacter and Escherichia coli, with two repeated sequences containing modules. Nevertheless, the pGR7 plasmid could replicate and be stably maintained only in Acetobacter strains and not in E. coli, another uncommon feature of this plasmid. The Rep protein was cloned into the pET30a + expression vector and purified by high-performance liquid chromatography. The helicase activity was determined and the ability of the protein to bind to the plasmid regulation region was confirmed by an electrophoretic mobility shift assay. The plasmid was stable in the Acetobacter cells after cultivation under nonselective conditions. By real-time polymerase chain reaction, the relative copy number of pGR7 was estimated to be seven copies per host chromosome equivalent.

  15. Closed form solution for a double quantum well using Gröbner basis

    NASA Astrophysics Data System (ADS)

    Acus, A.; Dargys, A.

    2011-07-01

    Analytical expressions for the spectrum, eigenfunctions and dipole matrix elements of a square double quantum well (DQW) are presented for a general case when the potential in different regions of the DQW has different heights and the effective masses are different. This was achieved by using a Gröbner basis algorithm that allowed us to disentangle the resulting coupled polynomials without explicitly solving the transcendental eigenvalue equation.

  16. Nonlinear Elastic Effects on the Energy Flux Deviation of Ultrasonic Waves in GR/EP Composites

    NASA Technical Reports Server (NTRS)

    Prosser, William H.; Kriz, R. D.; Fitting, Dale W.

    1992-01-01

    In isotropic materials, the direction of the energy flux (energy per unit time per unit area) of an ultrasonic plane wave is always along the same direction as the normal to the wave front. In anisotropic materials, however, this is true only along symmetry directions. Along other directions, the energy flux of the wave deviates from the intended direction of propagation. This phenomenon is known as energy flux deviation and is illustrated. The direction of the energy flux is dependent on the elastic coefficients of the material. This effect has been demonstrated in many anisotropic crystalline materials. In transparent quartz crystals, Schlieren photographs have been obtained which allow visualization of the ultrasonic waves and the energy flux deviation. The energy flux deviation in graphite/epoxy (gr/ep) composite materials can be quite large because of their high anisotropy. The flux deviation angle has been calculated for unidirectional gr/ep composites as a function of both fiber orientation and fiber volume content. Experimental measurements have also been made in unidirectional composites. It has been further demonstrated that changes in composite materials which alter the elastic properties such as moisture absorption by the matrix or fiber degradation, can be detected nondestructively by measurements of the energy flux shift. In this research, the effects of nonlinear elasticity on energy flux deviation in unidirectional gr/ep composites were studied. Because of elastic nonlinearity, the angle of the energy flux deviation was shown to be a function of applied stress. This shift in flux deviation was modeled using acoustoelastic theory and the previously measured second and third order elastic stiffness coefficients for T300/5208 gr/ep. Two conditions of applied uniaxial stress were considered. In the first case, the direction of applied uniaxial stress was along the fiber axis (x3) while in the second case it was perpendicular to the fiber axis along the

  17. Spin-polarization inversion at small organic molecule/Fe{sub 4}N interfaces: A first-principles study

    SciTech Connect

    Zhang, Qian; Mi, Wenbo

    2015-09-21

    We report the first-principles calculations on the electronic structure and simulation of the spin-polarized scan tunneling microscopy graphic of the small organic molecules (benzene, thiophene, and cyclopentadienyl)/Fe{sub 4}N interfaces. It is found that the plane of benzene and thiophene keeps parallel to Fe{sub 4}N surface, while that of cyclopentadienyl does not. For all the systems, the organic molecules bind strongly with Fe{sub 4}N. Due to the hybridization between molecule p{sub z} orbitals and d orbitals of Fe, i.e., Zener interaction, all the three systems realize the spin-polarization inversion, whereas the spatial spin-polarization inversion distribution shows different intensities influenced by the competition between the spin polarization of C p{sub z} and Fe d states.

  18. A mildly relativistic radio jet from the otherwise normal type Ic supernova 2007gr.

    PubMed

    Paragi, Z; Taylor, G B; Kouveliotou, C; Granot, J; Ramirez-Ruiz, E; Bietenholz, M; van der Horst, A J; Pidopryhora, Y; van Langevelde, H J; Garrett, M A; Szomoru, A; Argo, M K; Bourke, S; Paczyński, B

    2010-01-28

    The class of type Ic supernovae have drawn increasing attention since 1998 owing to their sparse association (only four so far) with long duration gamma-ray bursts (GRBs). Although both phenomena originate from the core collapse of a massive star, supernovae emit mostly at optical wavelengths, whereas GRBs emit mostly in soft gamma-rays or hard X-rays. Though the GRB central engine generates ultra-relativistic jets, which beam the early emission into a narrow cone, no relativistic outflows have hitherto been found in type Ib/c supernovae explosions, despite theoretical expectations and searches. Here we report radio (interferometric) observations that reveal a mildly relativistic expansion in a nearby type Ic supernova, SN 2007gr. Using two observational epochs 60 days apart, we detect expansion of the source and establish a conservative lower limit for the average apparent expansion velocity of 0.6c. Independently, a second mildly relativistic supernova has been reported. Contrary to the radio data, optical observations of SN 2007gr indicate a typical type Ic supernova with ejecta velocities approximately 6,000 km s(-1), much lower than in GRB-associated supernovae. We conclude that in SN 2007gr a small fraction of the ejecta produced a low-energy mildly relativistic bipolar radio jet, while the bulk of the ejecta were slower and, as shown by optical spectropolarimetry, mildly aspherical.

  19. Rapid Verification of Terminators Using the pGR-Blue Plasmid and Golden Gate Assembly.

    PubMed

    Bradshaw, Jace C; Gongola, Allea Belle; Reyna, Nathan S

    2016-01-01

    The goal of this protocol is to allow for the rapid verification of bioinformatically identified terminators. Further, the plasmid (pGR-Blue) is designed specifically for this protocol and allows for the quantification of terminator efficiency. As a proof of concept, six terminators were bioinformatically identified in the mycobacteriophage Bernal13. Once identified, terminators were then made as oligonucleotides with the appropriate sticky ends and annealed together. Using Golden Gate Assembly (GGA), terminators were then cloned into pGR-Blue. Under visible light, false positive colonies appear blue and positively transformed colonies are white/yellow. After induction of an arabinose inducible promoter (pBad) with arabinose, colony strength can be determined by measuring the ratio of green fluorescent protein (GFP) produced to red fluorescent protein (RFP) produced. With pGR-Blue, the protocol can be completed in as little as three days and is ideal in an educational setting. Additionally, results show that this protocol is useful as a means for understanding in silico predictions of terminator efficiency related to the regulation of transcription. PMID:27167700

  20. Thermodynamic signature of quantum criticality: universally diverging Grüneisen ratio

    NASA Astrophysics Data System (ADS)

    Zhu, Lijun

    2005-03-01

    At a generic quantum critical point where pressure acts as (or couples to) the zero-temperature control parameter, the Grüneisen ratio γ (the ratio of thermal expansion to specific heat) is divergent[1]. This property provides a novel probe to quantum criticality from thermodynamics. When scaling applies, γ˜1/T^x at the critical pressure p=pc, where the exponent x measures the scaling dimension of the most singular operator coupled to pressure; in the alternative limit T ->0 and p !=pc, γ= Gr/(p-pc), where Gr is a universal combination of critical exponents. The predicted divergence has been observed near the quantum critical points of several heavy fermion metals[2]. Analyses based on specific models relevant to these experiments are also presented. [1] L. Zhu, M. Garst, A. Rosch, and Q. Si, Phys. Rev. Lett. 91, 066404 (2003). [2] R. Küchler et al., Phys. Rev. Lett. 91, 066405 (2003); ibid. 93, 096402 (2004).

  1. Volvulus du grêle sur paquet d’ascaris: à propos d’un cas

    PubMed Central

    Diouf, Cheikh; Kane, Ahmed; Ndoye, Ndeye Aby; Ndour, Oumar; Faye-Fall, Aimé Lakh; Fall, Mbaye; Alumeti, Désiré Munyali; Ngom, Gabriel

    2016-01-01

    Nous rapportons un cas exceptionnel de volvulus nécrosé de l'intestin grêle dû à des ascaris adultes chez un enfant de 7 ans. A l'admission, l'enfant présentait le tableau d'occlusion intestinale qui évoluait depuis deux jours avec altération de l'état général. La radiographie de l'abdomen sans préparation retrouvait des niveaux hydroaériques de type grêlique et un aspect tigré évoquant le diagnostic d'une occlusion intestinale haute sur masse abdominale. Après la réanimation, le traitement chirurgical consistait en une laparotomie qui avait retrouvé un volvulus nécrosé de l'iléon terminale contenant des ascaris adultes. Une résection du grêle sur environ un mètre emportant le segment nécrosé suivie d'une iléostomie était réalisée. L'évolution a été favorable, l'anastomose iléo-colique fut réalisée quatre semaines plus tard. Au recul de deux ans l'enfant est indemne de tout symptôme. PMID:27795803

  2. A mildly relativistic radio jet from the otherwise normal type Ic supernova 2007gr

    NASA Astrophysics Data System (ADS)

    Paragi, Z.; Taylor, G. B.; Kouveliotou, C.; Granot, J.; Ramirez-Ruiz, E.; Bietenholz, M.; van der Horst, A. J.; Pidopryhora, Y.; van Langevelde, H. J.; Garrett, M. A.; Szomoru, A.; Argo, M. K.; Bourke, S.; Paczyński, B.

    2010-01-01

    The class of type Ic supernovae have drawn increasing attention since 1998 owing to their sparse association (only four so far) with long duration γ-ray bursts (GRBs). Although both phenomena originate from the core collapse of a massive star, supernovae emit mostly at optical wavelengths, whereas GRBs emit mostly in soft γ-rays or hard X-rays. Though the GRB central engine generates ultra-relativistic jets, which beam the early emission into a narrow cone, no relativistic outflows have hitherto been found in type Ib/c supernovae explosions, despite theoretical expectations and searches. Here we report radio (interferometric) observations that reveal a mildly relativistic expansion in a nearby type Ic supernova, SN 2007gr. Using two observational epochs 60days apart, we detect expansion of the source and establish a conservative lower limit for the average apparent expansion velocity of 0.6c. Independently, a second mildly relativistic supernova has been reported. Contrary to the radio data, optical observations of SN 2007gr indicate a typical type Ic supernova with ejecta velocities ~6,000kms-1, much lower than in GRB-associated supernovae. We conclude that in SN 2007gr a small fraction of the ejecta produced a low-energy mildly relativistic bipolar radio jet, while the bulk of the ejecta were slower and, as shown by optical spectropolarimetry, mildly aspherical.

  3. Direct GR Binding Sites Potentiate Clusters of TF Binding across the Human Genome.

    PubMed

    Vockley, Christopher M; D'Ippolito, Anthony M; McDowell, Ian C; Majoros, William H; Safi, Alexias; Song, Lingyun; Crawford, Gregory E; Reddy, Timothy E

    2016-08-25

    The glucocorticoid receptor (GR) binds the human genome at >10,000 sites but only regulates the expression of hundreds of genes. To determine the functional effect of each site, we measured the glucocorticoid (GC) responsive activity of nearly all GR binding sites (GBSs) captured using chromatin immunoprecipitation (ChIP) in A549 cells. 13% of GBSs assayed had GC-induced activity. The responsive sites were defined by direct GR binding via a GC response element (GRE) and exclusively increased reporter-gene expression. Meanwhile, most GBSs lacked GC-induced reporter activity. The non-responsive sites had epigenetic features of steady-state enhancers and clustered around direct GBSs. Together, our data support a model in which clusters of GBSs observed with ChIP-seq reflect interactions between direct and tethered GBSs over tens of kilobases. We further show that those interactions can synergistically modulate the activity of direct GBSs and may therefore play a major role in driving gene activation in response to GCs. PMID:27565349

  4. Direct GR Binding Sites Potentiate Clusters of TF Binding across the Human Genome.

    PubMed

    Vockley, Christopher M; D'Ippolito, Anthony M; McDowell, Ian C; Majoros, William H; Safi, Alexias; Song, Lingyun; Crawford, Gregory E; Reddy, Timothy E

    2016-08-25

    The glucocorticoid receptor (GR) binds the human genome at >10,000 sites but only regulates the expression of hundreds of genes. To determine the functional effect of each site, we measured the glucocorticoid (GC) responsive activity of nearly all GR binding sites (GBSs) captured using chromatin immunoprecipitation (ChIP) in A549 cells. 13% of GBSs assayed had GC-induced activity. The responsive sites were defined by direct GR binding via a GC response element (GRE) and exclusively increased reporter-gene expression. Meanwhile, most GBSs lacked GC-induced reporter activity. The non-responsive sites had epigenetic features of steady-state enhancers and clustered around direct GBSs. Together, our data support a model in which clusters of GBSs observed with ChIP-seq reflect interactions between direct and tethered GBSs over tens of kilobases. We further show that those interactions can synergistically modulate the activity of direct GBSs and may therefore play a major role in driving gene activation in response to GCs.

  5. Structural Modeling of GR Interactions with the SWI/SNF Chromatin Remodeling Complex and C/EBP.

    PubMed

    Muratcioglu, Serena; Presman, Diego M; Pooley, John R; Grøntved, Lars; Hager, Gordon L; Nussinov, Ruth; Keskin, Ozlem; Gursoy, Attila

    2015-09-15

    The glucocorticoid receptor (GR) is a steroid-hormone-activated transcription factor that modulates gene expression. Transcriptional regulation by the GR requires dynamic receptor binding to specific target sites located across the genome. This binding remodels the chromatin structure to allow interaction with other transcription factors. Thus, chromatin remodeling is an essential component of GR-mediated transcriptional regulation, and understanding the interactions between these molecules at the structural level provides insights into the mechanisms of how GR and chromatin remodeling cooperate to regulate gene expression. This study suggests models for the assembly of the SWI/SNF-A (SWItch/Sucrose-NonFermentable) complex and its interaction with the GR. We used the PRISM algorithm (PRotein Interactions by Structural Matching) to predict the three-dimensional complex structures of the target proteins. The structural models indicate that BAF57 and/or BAF250 mediate the interaction between the GR and the SWI/SNF-A complex, corroborating experimental data. They further suggest that a BAF60a/BAF155 and/or BAF60a/BAF170 interaction is critical for association between the core and variant subunits. Further, we model the interaction between GR and CCAAT-enhancer-binding proteins (C/EBPs), since the GR can regulate gene expression indirectly by interacting with other transcription factors like C/EBPs. We observe that GR can bind to bZip domains of the C/EBPα homodimer as both a monomer and dimer of the DNA-binding domain. In silico mutagenesis of the predicted interface residues confirm the importance of these residues in binding. In vivo analysis of the computationally suggested mutations reveals that double mutations of the leucine residues (L317D+L335D) may disrupt the interaction between GR and C/EBPα. Determination of the complex structures of the GR is of fundamental relevance to understanding its interactions and functions, since the function of a protein or a

  6. Structural Modeling of GR Interactions with the SWI/SNF Chromatin Remodeling Complex and C/EBP.

    PubMed

    Muratcioglu, Serena; Presman, Diego M; Pooley, John R; Grøntved, Lars; Hager, Gordon L; Nussinov, Ruth; Keskin, Ozlem; Gursoy, Attila

    2015-09-15

    The glucocorticoid receptor (GR) is a steroid-hormone-activated transcription factor that modulates gene expression. Transcriptional regulation by the GR requires dynamic receptor binding to specific target sites located across the genome. This binding remodels the chromatin structure to allow interaction with other transcription factors. Thus, chromatin remodeling is an essential component of GR-mediated transcriptional regulation, and understanding the interactions between these molecules at the structural level provides insights into the mechanisms of how GR and chromatin remodeling cooperate to regulate gene expression. This study suggests models for the assembly of the SWI/SNF-A (SWItch/Sucrose-NonFermentable) complex and its interaction with the GR. We used the PRISM algorithm (PRotein Interactions by Structural Matching) to predict the three-dimensional complex structures of the target proteins. The structural models indicate that BAF57 and/or BAF250 mediate the interaction between the GR and the SWI/SNF-A complex, corroborating experimental data. They further suggest that a BAF60a/BAF155 and/or BAF60a/BAF170 interaction is critical for association between the core and variant subunits. Further, we model the interaction between GR and CCAAT-enhancer-binding proteins (C/EBPs), since the GR can regulate gene expression indirectly by interacting with other transcription factors like C/EBPs. We observe that GR can bind to bZip domains of the C/EBPα homodimer as both a monomer and dimer of the DNA-binding domain. In silico mutagenesis of the predicted interface residues confirm the importance of these residues in binding. In vivo analysis of the computationally suggested mutations reveals that double mutations of the leucine residues (L317D+L335D) may disrupt the interaction between GR and C/EBPα. Determination of the complex structures of the GR is of fundamental relevance to understanding its interactions and functions, since the function of a protein or a

  7. Characterization of an H4N2 avian influenza virus isolated from domestic duck in Dongting Lake wetland in 2009.

    PubMed

    Zhang, Hongbo; Chen, Quanjiao; Chen, Ze

    2012-02-01

    In January 2009, an H4N2 subtype of avian influenza virus [A/duck/Hunan/8-19/2009 (H4N2)] was isolated from domestic ducks in Dongting Lake wetland. The whole genome of the virus was sequenced and the results indicated that multiple gene segments of the virus had a high homology with viruses isolated from wild waterfowl, which indicated that the virus was probably transmitted from wild waterfowl to domestic ducks. Phylogenetic analysis revealed that the each gene belonged to the Eurasian lineage of avian influenza viruses, but genetic reassortment occurs between viruses of different subtypes.

  8. A Novel Point Mutation in the Amino Terminal Domain of the Human Glucocorticoid Receptor (hGR) Gene Enhancing hGR-Mediated Gene Expression

    PubMed Central

    Charmandari, Evangelia; Ichijo, Takamasa; Jubiz, William; Baid, Smita; Zachman, Keith; Chrousos, George P.; Kino, Tomoshige

    2008-01-01

    Context: Interindividual variations in glucocorticoid sensitivity have been associated with manifestations of cortisol excess or deficiency and may be partly explained by polymorphisms in the human glucocorticoid receptor (hGR) gene. We studied a 43-yr-old female, who presented with manifestations consistent with tissue-selective glucocorticoid hypersensitivity. We detected a novel, single, heterozygous nucleotide (G → C) substitution at position 1201 (exon 2) of the hGR gene, which resulted in aspartic acid to histidine substitution at amino acid position 401 in the amino-terminal domain of the hGRα. We investigated the molecular mechanisms of action of the natural mutant receptor hGRαD401H. Methods-Results: Compared with the wild-type hGRα, the mutant receptor hGRαD401H demonstrated a 2.4-fold increase in its ability to transactivate the glucocorticoid-inducible mouse mammary tumor virus promoter in response to dexamethasone but had similar affinity for the ligand (dissociation constant = 6.2 ± 0.6 vs. 6.1 ± 0.6 nm) and time to nuclear translocation (14.75 ± 0.25 vs. 14.25 ± 1.13 min). The mutant receptor hGRαD401H did not exert a dominant positive or negative effect upon the wild-type receptor, it preserved its ability to bind to glucocorticoid response elements, and displayed a normal interaction with the glucocorticoid receptor-interacting protein 1 coactivator. Conclusions: The mutant receptor hGRαD401H enhances the transcriptional activity of glucocorticoid-responsive genes. The presence of the D401H mutation may predispose subjects to obesity, hypertension, and other manifestations of the metabolic syndrome. PMID:18827003

  9. Amine templating effect absent in uranyl sulfates synthesized with 1,4-n-butyldiamine

    SciTech Connect

    Jouffret, Laurent J.; Wylie, Ernest M.; Burns, Peter C.

    2013-01-15

    Two new uranyl sulfates, (C{sub 4}H{sub 14}N{sub 2})[(UO{sub 2}){sub 2}(SO{sub 4}){sub 3}(H{sub 2}O)]{center_dot}2H{sub 2}O (NDUS2) and (C{sub 4}H{sub 14}N{sub 2})[(UO{sub 2})(SO{sub 4}){sub 2}(H{sub 2}O)]{center_dot}2H{sub 2}O (NDUS3), were synthesized and their crystal structures determined. NDUS2 was obtained in highly acidic media heat-treated at 373 K and subsequently maintained at 278 K until crystals formed after two months. NDUS3 results from the degradation of NDUS2 over the course of a few days. NDUS2 and NDUS3 crystallize in the monoclinic space group P2{sub 1}/n, a=10.9075(4) A, b=10.4513(4) A, c=17.7881(7) A, {beta}=97.908(2) Degree-Sign , V=2008.52(13) A{sup 3}, Z=4, at 140 K and a=8.8570(4) A, b=7.3299(3) A, c=20.4260(9) A, {beta}=95.140(2) Degree-Sign , V=1320.74(10) A{sup 3}, Z=4, at 140 K, respectively. The compounds contain interlayer 1,4-n-butyldiammonium cations that charge-balance the anionic structural units. - Graphical abstract: Amine templating effect absent in uranyl sulfates synthesized with 1,4-diaminobutane, as shown by the synthesis of two new uranyl sulfates, (C{sub 4}H{sub 14}N{sub 2})[(UO{sub 2}){sub 2}(SO{sub 4}){sub 3}(H{sub 2}O)]{center_dot}2H{sub 2}O (NDUS2) and (C{sub 4}H{sub 14}N{sub 2})[(UO{sub 2})(SO{sub 4}){sub 2}(H{sub 2}O)]{center_dot}2H{sub 2}O (NDUS3). Highlights: Black-Right-Pointing-Pointer Two layered uranyl sulfates were synthesized. Black-Right-Pointing-Pointer Amine molecules are located in the interlayers of the compounds. Black-Right-Pointing-Pointer No templating effect of the amine was observed. Black-Right-Pointing-Pointer Amine molecules are only charge balancing cations in the structures.

  10. GR@PPA 2.7 event generator for pp/pp¯ collisions

    NASA Astrophysics Data System (ADS)

    Tsuno, S.; Kaneko, T.; Kurihara, Y.; Odaka, S.; Kato, K.

    2006-11-01

    The GR@PPA event generator has been updated to version 2.7. This distribution provides event generators for V ( W or Z) + jets (⩽4 jets), VV+jets (⩽2 jets) and QCD multi-jet (⩽4 jets) production processes at pp and pp¯ collisions, in addition to the four bottom quark productions implemented in our previous work (GR@PPA_4b). Also included are the top-pair and top-pair + jet production processes, where the correlation between the decay products are fully reproduced at the tree level. Namely, processes up to seven-body productions can be simulated, based on ordinary Feynman diagram calculations at the tree level. In this version, the GR@PPA framework and the process dependent matrix-element routines are separately provided. This makes it easier to add further new processes, and allows users to make a choice of processes to implement. This version also has several new features to handle complicated multi-body production processes. A systematic way to combine many subprocesses to a single base-subprocess has been introduced, and a new method has been adopted to calculate the color factors of complicated QCD processes. They speed up the calculation significantly. Program summaryTitle of program:GR@PPA (v2.7) Catalogue identifier:ADRH_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADRH_v2_0 Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Operating system under which the program has been tested:UNIX Programming language used:Fortran77 Other CPC library programs required:PYTHIA, HERWIG, BASES, SPRING Memory required to execute with typical data:56.5 kwords for an integration, 74.6 kwords for an event generation Number of bytes in distributed program, including test data, etc.: 570 587 No. of lines in distributed program, including test data, etc.:143 327 Distribution format:tar.gz Nature of physical problem:The multi-legs interaction processes have become more important with increasing the colliding energy available

  11. Melanin production by Rhizobium meliloti GR4 is linked to nonsymbiotic plasmid pRmeGR4b: cloning, sequencing, and expression of the tyrosinase gene mepA.

    PubMed Central

    Mercado-Blanco, J; García, F; Fernández-López, M; Olivares, J

    1993-01-01

    Melanin production by Rhizobium meliloti GR4 is linked to nonsymbiotic plasmid pRmeGR4b (140 MDa). Transfer of this plasmid to GR4-cured derivatives or to Agrobacterium tumefaciens enables these bacteria to produce melanin. Sequence analysis of a 3.5-kb PstI fragment of plasmid pRmeGR4b has revealed the presence of a open reading frame 1,481-bp that codes for a protein whose sequence shows strong homology to two conserved regions involved in copper binding in tyrosinases and hemocyanins. In vitro-coupled transcription-translation experiments showed that this open reading frame codes for a 55-kDa polypeptide. Melanin production in GR4 is not under the control of the RpoN-NifA regulatory system, unlike that in R. leguminosarum bv. phaseoli 8002. The GR4 tyrosinase gene could be expressed in Escherichia coli under the control of the lacZ promoter. For avoiding confusion with mel genes (for melibiose), a change of the name of the previously reported mel genes of R. leguminosarum bv. phaseoli and other organisms to mep genes (for melanin production) is proposed. Images PMID:8366027

  12. A comparative study of Burakovsky's and Jacobs's volume dependence Grüneisen parameter for fcc aluminum

    NASA Astrophysics Data System (ADS)

    Nie, Chuanhui; Zong, Baochun; Wang, Junping

    2015-07-01

    We compare two expressions for the volume dependence of the Grüneisen parameter γ for fcc Al presented by Burakovsky and Preston (2004) [3] and Jacobs and Schmid-Fetzer (2010) [4], respectively. It's found that both calculated results of the melting temperature Tm are in good agreement with experimental data. But the higher order Grüneisen parameters are different. We obtain the values of the third order Grüneisen parameter λ∞ and the pressure derivative of bulk modulus K‧∞ at extreme pressure, and the parameter f in the generalized free volume formula for the two models. The results show that the Jacobs's expression of Grüneisen parameter is more suitable for fcc Al.

  13. Expression of AmGR10 of the Gustatory Receptor Family in Honey Bee Is Correlated with Nursing Behavior

    PubMed Central

    Paerhati, Yisilahaiti; Ishiguro, Shinichi; Ueda-Matsuo, Risa; Yang, Ping; Yamashita, Tetsuro; Ito, Kikukatsu; Maekawa, Hideaki; Tani, Hiroko; Suzuki, Koichi

    2015-01-01

    We investigated the association between the expression of a gene encoding gustatory receptor (G10) and division of labor in the honey bee, Apis mellifera. Among 10 GR genes encoding proteins 15% ~ 99% amino acid identity in the honey bee, we found that AmGR10 with 99% identity is involved in nursing or brood care. Expression of AmGR10 was restricted to organs of the hypopharyngeal gland, brain, and ovary in the nurse bee phase. Members of an extended nursing caste under natural conditions continued to express this gene. RNAi knockdown of AmGR10 accelerated the transition to foraging. Our findings demonstrate that this one gene has profound effects on the division of labor associated with the development and physiology of honeybee society. PMID:26588091

  14. Nuclear and axonal localization of Ca2+/calmodulin-dependent protein kinase type Gr in rat cerebellar cortex.

    PubMed Central

    Jensen, K F; Ohmstede, C A; Fisher, R S; Sahyoun, N

    1991-01-01

    The granule cell-enriched Ca2+/calmodulin-dependent protein kinase (CaM kinase-Gr) is a recently discovered neuron-specific enzyme. The kinase avidly phosphorylates synapsin I and contains a polyglutamate sequence, which suggests an association with chromatin as well. A possible role in synapsin I phosphorylation and in nuclear Ca2+ signaling was supported by immunochemical and ultrastructural examination of CaM kinase-Gr distribution. CaM kinase-Gr immunoreactivity was present in the molecular and granule cell layers of the rat cerebellum. This pattern corresponded to the occurrence of the enzyme in the granule cell axons and nuclei, respectively. Immunoblots confirmed these findings. Thus, CaM kinase-Gr may mediate and coordinate Ca2(+)-signaling within different subcellular compartments. Images PMID:2011593

  15. AF4 and AF4N protein complexes: recruitment of P-TEFb kinase, their interactome and potential functions

    PubMed Central

    Scholz, Bastian; Kowarz, Eric; Rössler, Tanja; Ahmad, Khalil; Steinhilber, Dieter; Marschalek, Rolf

    2015-01-01

    AF4/AFF1 and AF5/AFF4 are the molecular backbone to assemble “super-elongation complexes” (SECs) that have two main functions: (1) control of transcriptional elongation by recruiting the positive transcription elongation factor b (P-TEFb = CyclinT1/CDK9) that is usually stored in inhibitory 7SK RNPs; (2) binding of different histone methyltransferases, like DOT1L, NSD1 and CARM1. This way, transcribed genes obtain specific histone signatures (e.g. H3K79me2/3, H3K36me2) to generate a transcriptional memory system. Here we addressed several questions: how is P-TEFb recruited into SEC, how is the AF4 interactome composed, and what is the function of the naturally occuring AF4N protein variant which exhibits only the first 360 amino acids of the AF4 full-length protein. Noteworthy, shorter protein variants are a specific feature of all AFF protein family members. Here, we demonstrate that full-length AF4 and AF4N are both catalyzing the transition of P-TEFb from 7SK RNP to their N-terminal domain. We have also mapped the protein-protein interaction network within both complexes. In addition, we have first evidence that the AF4N protein also recruits TFIIH and the tumor suppressor MEN1. This indicate that AF4N may have additional functions in transcriptional initiation and in MEN1-dependend transcriptional processes. PMID:26171280

  16. Structure, phase transitions, and isotope effects in [(CH3)4N]2PuCl6

    SciTech Connect

    Wilson, Richard E.

    2015-11-02

    The single crystal X-ray diffraction structure of [(CH3)4N]2PuCl6 is presented for the first time, resolving long standing confusion and speculation regarding the structure of this compound in the literature. A temperature dependent study of this compound shows that the structure of [(CH3)4N]2PuCl6 undergoes no fewer than two phase transitions between 100 and 360 K. The phase of [(CH3)4N]2PuCl6 at room temperature is Fd-3c a = 26.012(3) Å. At 360 K, the structure is in space group Fm-3m with a = 13.088(1) Å. The plutonium octahedra and tetramethylammonium cations undergo a rotative displacement and the degree of rotation varies with temperature, giving rise to the phase transition from Fm-3m to Fd-3c as the crystal is cooled. Synthesis and structural studies of the deuterated salt [(CD3)4N]2PuCl6 suggest that there is an isotopic effect associated with this phase transition as revealed by a changing transition temperature in the deuterated versus protonated compound indicating that the donor-acceptor interactions between the tetramethylammonium cations and the hexachloroplutonate anions are driving the phase transformation.

  17. The non-ligand binding beta-isoform of the human glucocorticoid receptor (hGR beta): tissue levels, mechanism of action, and potential physiologic role.

    PubMed Central

    de Castro, M.; Elliot, S.; Kino, T.; Bamberger, C.; Karl, M.; Webster, E.; Chrousos, G. P.

    1996-01-01

    BACKGROUND: Alternative splicing of the transcripts of the human glucocorticoid receptor gene results in two mutually exclusive products, the classic, ligand-binding glucocorticoid receptor (hGR alpha), and a dominant negative non-ligand-binding isoform, hGR beta. MATERIALS AND METHODS: We examined the existence of and quantified both hGR alpha and hGR beta isoforms in a panel of human tissues, as well as in intact and fractionated HeLa cells, using specific quantitative Western blots and/or immunocytochemistry. We studied the potential interactions of hGR beta with heat shock protein (hsp) 90 and/or hGR alpha using cross-immunoadsorption/precipitation procedures followed by Western blots. RESULTS: For the first time, we demonstrated the natural existence of the hGR beta protein, which was widely expressed in human tissues. The ratio of immunoreactive hGR alpha to hGR beta varied from 0.2 to 1.0 among different tissues, and was approximately 0.2 in HeLa cells. In the latter, both isoforms were distributed in the cytoplasm and nucleus in the absence of the hormonal ligand, and translocated into the nucleus after addition of dexamethasone. The cytosolic and nuclear hGR alpha-to-hGR beta ratio remained the same before and after dexamethasone exposure, suggesting that upon activation the two isoforms translocated into the nucleus in equal proportions. hGR alpha- and hGR beta-specific antibodies cross-adsorbed and precipitated cytosolic and nuclear glucocorticoid hGR alpha and hGR beta, respectively, as well as hsp90, suggesting that hGR alpha and hGR beta are in complex with hsp90 and/or each other. CONCLUSIONS: The hGR beta protein is widely expressed throughout the human body and present mostly in the cytoplasm of human cells, in complex with hsp90 and other proteins. In the presence of glucocorticoid, hGR beta probably heterodimerizes with ligand-bound hGR alpha and translocates into the nucleus to act as a dominant negative inhibitor of the classic receptor. Images

  18. αB-Crystallin regulates expansion of CD11b+Gr-1+ immature myeloid cells during tumor progression

    PubMed Central

    Dieterich, Lothar C.; Schiller, Petter; Huang, Hua; Wawrousek, Eric F.; Loskog, Angelica; Wanders, Alkwin; Moons, Lieve; Dimberg, Anna

    2013-01-01

    The molecular chaperone αB-crystallin has emerged as a target for cancer therapy due to its expression in human tumors and its role in regulating tumor angiogenesis. αB-crystallin also reduces neuroinflammation, but its role in other inflammatory conditions has not been investigated. Here, we examined whether αB-crystallin regulates inflammation associated with tumors and ischemia. We found that CD45+ leukocyte infiltration is 3-fold increased in tumors and ischemic myocardium in αB-crystallin-deficient mice. Notably, αB-crystallin is prominently expressed in CD11b+ Gr-1+ immature myeloid cells (IMCs), known as regulators of angiogenesis and immune responses, while lymphocytes and mature granulocytes show low αB-crystallin expression. αB-Crystallin deficiency results in a 3-fold higher accumulation of CD11b+ Gr-1+ IMCs in tumors and a significant rise in CD11b+ Gr-1+ IMCs in spleen and bone marrow. Similarly, we noted a 2-fold increase in CD11b+ Gr-1+ IMCs in chronically inflamed livers in αB-crystallin-deficient mice. The effect of αB-crystallin on IMC accumulation is limited to pathological conditions, as CD11b+ Gr-1+ IMCs are not elevated in naive mice. Through ex vivo differentiation of CD11b+ Gr-1+ cells, we provide evidence that αB-crystallin regulates systemic expansion of IMCs through a cell-intrinsic mechanism. Our study suggests a key role of αB-crystallin in limiting expansion of CD11b+ Gr-1+ IMCs in diverse pathological conditions.—Dieterich, L. C., Schiller, P., Huang, H., Wawrousek, E. F., Loskog, A., Wanders, A., Moons, L., Dimberg, A. αB-Crystallin regulates expansion of CD11b+Gr-1+ immature myeloid cells during tumor progression. PMID:23033322

  19. The alc-GR system: a modified alc gene switch designed for use in plant tissue culture.

    PubMed

    Roberts, Gethin R; Garoosi, G Ali; Koroleva, Olga; Ito, Masaki; Laufs, Patrick; Leader, David J; Caddick, Mark X; Doonan, John H; Tomsett, A Brian

    2005-07-01

    The ALCR/alcA (alc) two-component, ethanol-inducible gene expression system provides stringent control of transgene expression in genetically modified plants. ALCR is an ethanol-activated transcription factor that can drive expression from the ALCR-responsive promoter (alcA). However, the alc system has been shown to have constitutive expression when used in plant callus or cell suspension cultures, possibly resulting from endogenous inducer produced in response to lowered oxygen availability. To widen the use of the alc system in plant cell culture conditions, the receptor domain of the rat glucocorticoid receptor (GR) was translationally fused to the C terminus of ALCR to produce ALCR-GR, which forms the basis of a glucocorticoid-inducible system (alc-GR). The alc-GR switch system was tested in tobacco (Nicotiana tabacum) Bright Yellow-2 suspension cells using a constitutively expressed ALCR-GR with four alternative alcA promoter-driven reporter genes: beta-glucuronidase, endoplasmic reticulum-targeted green fluorescent protein, haemagglutinin, and green fluorescent protein-tagged Arabidopsis (Arabidopsis thaliana) Arath;CDKA;1 cyclin-dependent kinase. Gene expression was shown to be stringently dependent on the synthetic glucocorticoid dexamethasone and, in cell suspensions, no longer required ethanol for induction. Thus, the alc-GR system allows tight control of alcA-driven genes in cell culture and complements the conventional ethanol switch used in whole plants. PMID:16010000

  20. The alc-GR System. A Modified alc Gene Switch Designed for Use in Plant Tissue Culture1[w

    PubMed Central

    Roberts, Gethin R.; Garoosi, G. Ali; Koroleva, Olga; Ito, Masaki; Laufs, Patrick; Leader, David J.; Caddick, Mark X.; Doonan, John H.; Tomsett, A. Brian

    2005-01-01

    The ALCR/alcA (alc) two-component, ethanol-inducible gene expression system provides stringent control of transgene expression in genetically modified plants. ALCR is an ethanol-activated transcription factor that can drive expression from the ALCR-responsive promoter (alcA). However, the alc system has been shown to have constitutive expression when used in plant callus or cell suspension cultures, possibly resulting from endogenous inducer produced in response to lowered oxygen availability. To widen the use of the alc system in plant cell culture conditions, the receptor domain of the rat glucocorticoid receptor (GR) was translationally fused to the C terminus of ALCR to produce ALCR-GR, which forms the basis of a glucocorticoid-inducible system (alc-GR). The alc-GR switch system was tested in tobacco (Nicotiana tabacum) Bright Yellow-2 suspension cells using a constitutively expressed ALCR-GR with four alternative alcA promoter-driven reporter genes: β-glucuronidase, endoplasmic reticulum-targeted green fluorescent protein, haemagglutinin, and green fluorescent protein-tagged Arabidopsis (Arabidopsis thaliana) Arath;CDKA;1 cyclin-dependent kinase. Gene expression was shown to be stringently dependent on the synthetic glucocorticoid dexamethasone and, in cell suspensions, no longer required ethanol for induction. Thus, the alc-GR system allows tight control of alcA-driven genes in cell culture and complements the conventional ethanol switch used in whole plants. PMID:16010000

  1. Glucocorticoid receptor (GR) immunohistochemical expression is correlated with cell cycle-related molecules in human colon cancer.

    PubMed

    Theocharis, Stamatios; Kouraklis, Gregorios; Margeli, Alexandra; Agapitos, Emmanuel; Ninos, Sotirios; Karatzas, Gabriel; Koutselinis, Antonios

    2003-09-01

    The aim of this study was to examine glucocorticoid receptor (GR) immunohistochemical expression in colon cancer histopathological specimens and to correlate it with clinicopathological parameters, tumor proliferative capacity, cell cycle-related molecule expression, and patients' survival. Primary tumoral samples from 91 colon cancer patients were immunostained for the detection of GR, cyclins D1 and E, Rb protein (pRb), p16, p21, and Ki-67, using the streptavidin-biotin-peroxidase technique. GR expression was correlated with tumor histopathological characteristics and proliferative capacity, cell cycle-related molecule expression, and patients' survival. GR positivity was prominent in 44 of 91 (48%) colon cancer cases and was positively correlated with the expression of cell cycle-related molecules pRb (P = 0.008) and p16 (P = 0.002), while lack of correlation was noted with cyclins D1 and E and p21. GR expression was not correlated with tumor location, grade of differentiation, Dukes' stage, lymph node and liver metastasis, venous invasion, tumor proliferative capacity (evident by Ki-67-labeling status) and patient survival. Our findings support evidence for GR participation in the biological mechanisms underlying the carcinogenic evolution in the colon, implying the use of glucocorticoids as an adjuvant treatment for cell cycle modulation in colon cancer cells.

  2. The alc-GR system: a modified alc gene switch designed for use in plant tissue culture.

    PubMed

    Roberts, Gethin R; Garoosi, G Ali; Koroleva, Olga; Ito, Masaki; Laufs, Patrick; Leader, David J; Caddick, Mark X; Doonan, John H; Tomsett, A Brian

    2005-07-01

    The ALCR/alcA (alc) two-component, ethanol-inducible gene expression system provides stringent control of transgene expression in genetically modified plants. ALCR is an ethanol-activated transcription factor that can drive expression from the ALCR-responsive promoter (alcA). However, the alc system has been shown to have constitutive expression when used in plant callus or cell suspension cultures, possibly resulting from endogenous inducer produced in response to lowered oxygen availability. To widen the use of the alc system in plant cell culture conditions, the receptor domain of the rat glucocorticoid receptor (GR) was translationally fused to the C terminus of ALCR to produce ALCR-GR, which forms the basis of a glucocorticoid-inducible system (alc-GR). The alc-GR switch system was tested in tobacco (Nicotiana tabacum) Bright Yellow-2 suspension cells using a constitutively expressed ALCR-GR with four alternative alcA promoter-driven reporter genes: beta-glucuronidase, endoplasmic reticulum-targeted green fluorescent protein, haemagglutinin, and green fluorescent protein-tagged Arabidopsis (Arabidopsis thaliana) Arath;CDKA;1 cyclin-dependent kinase. Gene expression was shown to be stringently dependent on the synthetic glucocorticoid dexamethasone and, in cell suspensions, no longer required ethanol for induction. Thus, the alc-GR system allows tight control of alcA-driven genes in cell culture and complements the conventional ethanol switch used in whole plants.

  3. GR 290 (Romano’s Star). II. Light History and Evolutionary State

    NASA Astrophysics Data System (ADS)

    Polcaro, V. F.; Maryeva, O.; Nesci, R.; Calabresi, M.; Chieffi, A.; Galleti, S.; Gualandi, R.; Haver, R.; Mills, O. F.; Osborn, W. H.; Pasquali, A.; Rossi, C.; Vasilyeva, T.; Viotti, R. F.

    2016-06-01

    We have investigated the past light history of the luminous variable star GR 290 (M33/V532, Romano’s Star) in the M33 galaxy, and collected new spectrophotometric observations in order to analyze links between this object, the LBV category, and the Wolf-Rayet stars of the nitrogen sequence. We have built the historical light curve of GR 290 back to 1901, from old observations of the star found in several archival plates of M33. These old recordings together with published and new data on the star allowed us to infer that for at least half a century the star was in a low luminosity state, with B ≃ 18-19, most likely without brighter luminosity phases. After 1960, five large variability cycles of visual luminosity were recorded. The amplitude of the oscillations was seen increasing toward the 1992-1994 maximum, then decreasing during the last maxima. The recent light curve indicates that the photometric variations have been quite similar in all the bands and that the B - V color index has been constant within ±0.1m despite the 1.5m change of the visual luminosity. The spectrum of GR 290 at the large maximum of 1992-94 was equivalent to late-B-type, while, during 2002-2014, it varied between WN10h-11h near the visual maxima to WN8h-9h at the luminosity minima. We have detected, during this same period, a clear anti-correlation between the visual luminosity, the strength of the He ii 4686 Å emission line, the strength of the 4600-4700 Å lines’ blend, and the spectral type. From a model analysis of the spectra collected during the whole 2002-2014 period, we find that the Rosseland radius R2/3, changed between the minimum and maximum luminosity phases by a factor of three while Teff varied between about 33,000 and 23,000 K. We confirm that the bolometric luminosity of the star has not been constant, but has increased by a factor of ˜1.5 between minimum and maximum luminosity, in phase with the apparent luminosity variations. Presently, GR 290 falls in the H

  4. GR 290 (Romano’s Star). II. Light History and Evolutionary State

    NASA Astrophysics Data System (ADS)

    Polcaro, V. F.; Maryeva, O.; Nesci, R.; Calabresi, M.; Chieffi, A.; Galleti, S.; Gualandi, R.; Haver, R.; Mills, O. F.; Osborn, W. H.; Pasquali, A.; Rossi, C.; Vasilyeva, T.; Viotti, R. F.

    2016-06-01

    We have investigated the past light history of the luminous variable star GR 290 (M33/V532, Romano’s Star) in the M33 galaxy, and collected new spectrophotometric observations in order to analyze links between this object, the LBV category, and the Wolf–Rayet stars of the nitrogen sequence. We have built the historical light curve of GR 290 back to 1901, from old observations of the star found in several archival plates of M33. These old recordings together with published and new data on the star allowed us to infer that for at least half a century the star was in a low luminosity state, with B ≃ 18–19, most likely without brighter luminosity phases. After 1960, five large variability cycles of visual luminosity were recorded. The amplitude of the oscillations was seen increasing toward the 1992–1994 maximum, then decreasing during the last maxima. The recent light curve indicates that the photometric variations have been quite similar in all the bands and that the B – V color index has been constant within ±0.1m despite the 1.5m change of the visual luminosity. The spectrum of GR 290 at the large maximum of 1992–94 was equivalent to late-B-type, while, during 2002–2014, it varied between WN10h-11h near the visual maxima to WN8h-9h at the luminosity minima. We have detected, during this same period, a clear anti-correlation between the visual luminosity, the strength of the He ii 4686 Å emission line, the strength of the 4600–4700 Å lines’ blend, and the spectral type. From a model analysis of the spectra collected during the whole 2002–2014 period, we find that the Rosseland radius R2/3, changed between the minimum and maximum luminosity phases by a factor of three while Teff varied between about 33,000 and 23,000 K. We confirm that the bolometric luminosity of the star has not been constant, but has increased by a factor of ∼1.5 between minimum and maximum luminosity, in phase with the apparent luminosity variations. Presently, GR 290

  5. A high mass progenitor for the Type Ic Supernova 2007gr inferred from its environment

    NASA Astrophysics Data System (ADS)

    Maund, Justyn R.; Ramirez-Ruiz, Enrico

    2016-03-01

    We present an analysis of late-time Hubble Space Telescope Wide Field Camera 3 (WFC3) and Wide Field Planetary Camera 2 (WFPC2) observations of the site of the Type Ic supernova (SN) 2007gr in NGC 1058. The SN is barely recovered in the late-time WFPC2 observations, while a possible detection in the later WFC3 data is debatable. These observations were used to conduct a multiwavelength study of the surrounding stellar population. We fit spatial profiles to a nearby bright source that was previously proposed to be a host cluster. We find that, rather than being an extended cluster, it is consistent with a single point-like object. Fitting stellar models to the observed spectral energy distribution of this source, we conclude it is A1-A3 Yellow Supergiant, possibly corresponding to a star with MZAMS = 40 M⊙. SN 2007gr is situated in a massive star association, with diameter of ≈300 pc. We present a Bayesian scheme to determine the properties of the surrounding massive star population, in conjunction with the Padova isochrones. We find that the stellar population, as observed in either the WFC3 and WFPC2 observations, can be well fit by two age distributions with mean ages: ˜6.3 Myr and ˜50 Myr. The stellar population is clearly dominated by the younger age solution (by factors of 3.5 and 5.7 from the WFPC2 and WFC3 observations, respectively), which corresponds to the lifetime of a star with MZAMS ˜ 30 M⊙. This is strong evidence in favour of the hypothesis that SN 2007gr arose from a massive progenitor star, possibly capable of becoming a Wolf-Rayet star.

  6. gr-MRI: A software package for magnetic resonance imaging using software defined radios.

    PubMed

    Hasselwander, Christopher J; Cao, Zhipeng; Grissom, William A

    2016-09-01

    The goal of this work is to develop software that enables the rapid implementation of custom MRI spectrometers using commercially-available software defined radios (SDRs). The developed gr-MRI software package comprises a set of Python scripts, flowgraphs, and signal generation and recording blocks for GNU Radio, an open-source SDR software package that is widely used in communications research. gr-MRI implements basic event sequencing functionality, and tools for system calibrations, multi-radio synchronization, and MR signal processing and image reconstruction. It includes four pulse sequences: a single-pulse sequence to record free induction signals, a gradient-recalled echo imaging sequence, a spin echo imaging sequence, and an inversion recovery spin echo imaging sequence. The sequences were used to perform phantom imaging scans with a 0.5Tesla tabletop MRI scanner and two commercially-available SDRs. One SDR was used for RF excitation and reception, and the other for gradient pulse generation. The total SDR hardware cost was approximately $2000. The frequency of radio desynchronization events and the frequency with which the software recovered from those events was also measured, and the SDR's ability to generate frequency-swept RF waveforms was validated and compared to the scanner's commercial spectrometer. The spin echo images geometrically matched those acquired using the commercial spectrometer, with no unexpected distortions. Desynchronization events were more likely to occur at the very beginning of an imaging scan, but were nearly eliminated if the user invoked the sequence for a short period before beginning data recording. The SDR produced a 500kHz bandwidth frequency-swept pulse with high fidelity, while the commercial spectrometer produced a waveform with large frequency spike errors. In conclusion, the developed gr-MRI software can be used to develop high-fidelity, low-cost custom MRI spectrometers using commercially-available SDRs. PMID:27394165

  7. gr-MRI: A software package for magnetic resonance imaging using software defined radios.

    PubMed

    Hasselwander, Christopher J; Cao, Zhipeng; Grissom, William A

    2016-09-01

    The goal of this work is to develop software that enables the rapid implementation of custom MRI spectrometers using commercially-available software defined radios (SDRs). The developed gr-MRI software package comprises a set of Python scripts, flowgraphs, and signal generation and recording blocks for GNU Radio, an open-source SDR software package that is widely used in communications research. gr-MRI implements basic event sequencing functionality, and tools for system calibrations, multi-radio synchronization, and MR signal processing and image reconstruction. It includes four pulse sequences: a single-pulse sequence to record free induction signals, a gradient-recalled echo imaging sequence, a spin echo imaging sequence, and an inversion recovery spin echo imaging sequence. The sequences were used to perform phantom imaging scans with a 0.5Tesla tabletop MRI scanner and two commercially-available SDRs. One SDR was used for RF excitation and reception, and the other for gradient pulse generation. The total SDR hardware cost was approximately $2000. The frequency of radio desynchronization events and the frequency with which the software recovered from those events was also measured, and the SDR's ability to generate frequency-swept RF waveforms was validated and compared to the scanner's commercial spectrometer. The spin echo images geometrically matched those acquired using the commercial spectrometer, with no unexpected distortions. Desynchronization events were more likely to occur at the very beginning of an imaging scan, but were nearly eliminated if the user invoked the sequence for a short period before beginning data recording. The SDR produced a 500kHz bandwidth frequency-swept pulse with high fidelity, while the commercial spectrometer produced a waveform with large frequency spike errors. In conclusion, the developed gr-MRI software can be used to develop high-fidelity, low-cost custom MRI spectrometers using commercially-available SDRs.

  8. gr-MRI: A software package for magnetic resonance imaging using software defined radios

    NASA Astrophysics Data System (ADS)

    Hasselwander, Christopher J.; Cao, Zhipeng; Grissom, William A.

    2016-09-01

    The goal of this work is to develop software that enables the rapid implementation of custom MRI spectrometers using commercially-available software defined radios (SDRs). The developed gr-MRI software package comprises a set of Python scripts, flowgraphs, and signal generation and recording blocks for GNU Radio, an open-source SDR software package that is widely used in communications research. gr-MRI implements basic event sequencing functionality, and tools for system calibrations, multi-radio synchronization, and MR signal processing and image reconstruction. It includes four pulse sequences: a single-pulse sequence to record free induction signals, a gradient-recalled echo imaging sequence, a spin echo imaging sequence, and an inversion recovery spin echo imaging sequence. The sequences were used to perform phantom imaging scans with a 0.5 Tesla tabletop MRI scanner and two commercially-available SDRs. One SDR was used for RF excitation and reception, and the other for gradient pulse generation. The total SDR hardware cost was approximately 2000. The frequency of radio desynchronization events and the frequency with which the software recovered from those events was also measured, and the SDR's ability to generate frequency-swept RF waveforms was validated and compared to the scanner's commercial spectrometer. The spin echo images geometrically matched those acquired using the commercial spectrometer, with no unexpected distortions. Desynchronization events were more likely to occur at the very beginning of an imaging scan, but were nearly eliminated if the user invoked the sequence for a short period before beginning data recording. The SDR produced a 500 kHz bandwidth frequency-swept pulse with high fidelity, while the commercial spectrometer produced a waveform with large frequency spike errors. In conclusion, the developed gr-MRI software can be used to develop high-fidelity, low-cost custom MRI spectrometers using commercially-available SDRs.

  9. The 2011 eruption of Grímsvötn volcano, Iceland

    NASA Astrophysics Data System (ADS)

    Lynch, Rebecca; Thordarson, Thorvaldur

    2015-04-01

    The 2011 eruption of Grímsvötn volcano, Iceland, was much more explosive than previous eruptions, specifically its 2004 eruption. This research examines the degassing processes of the 2011 eruption, through density and vesicule analyses, to help uncover the reasons for the more vigorous eruption. Over 1200 collected tephra samples from the 2011 sequences are measured for density and vesicularity. Several samples are chosen to be representative of eruptive phases; samples from the beginning of the eruption, the mid-eruption and the end phases are chosen. These pumice samples are impregnated with epoxy and made into plugs for use in a Scanning Electron Microscope with which, a nested image approach is taken to image the vesicules of the samples at different magnifications. Each backscatter image is converted to binary and corrected using GIMP. Using ImageJ software, quantitative vesicularity analysis of the images is performed and results are converted to volume. The density, quantitative vesicularity, and volume results are assessed for patterns and the processes of the magma during the ascent in the conduit and eruptive phases are inferred. The objective of this research is to use the microscopic vesicularity analyses of the eruptive products to theorize the larger scale magmatic and degassing processes and to understand why the 2011 Grímsvötn eruption was uncharacteristically explosive. Currently, the results are being examined and have not been included in this abstract, however the research will be finalized in time for presentation at the EGU 2015 conference. Keywords: Grímsvötn volcano, quantitative vesicularity analysis, bubble size distribution, volcanic degassing, conduit processes

  10. Metastatic Neuroblastoma Confined to Distant Lymph Nodes (stage 4N) Predicts Outcome in Patients With Stage 4 Disease: A Study From the International Neuroblastoma Risk Group Database

    PubMed Central

    Morgenstern, Daniel A.; London, Wendy B.; Stephens, Derek; Volchenboum, Samuel L.; Hero, Barbara; Di Cataldo, Andrea; Nakagawara, Akira; Shimada, Hiroyuki; Ambros, Peter F.; Matthay, Katherine K.; Cohn, Susan L.; Pearson, Andrew D.J.; Irwin, Meredith S.

    2014-01-01

    Purpose The presence of distant metastases is one of the most powerful predictors of outcome in patients with neuroblastoma. However, the pattern of metastatic spread is not incorporated into current risk stratification systems. Small case series have suggested that patients with neuroblastoma who have metastatic disease limited to distant lymph nodes (4N disease) may have improved outcomes. Patients and Methods We analyzed retrospective data from the International Neuroblastoma Risk Group database for patients diagnosed from 1990 to 2002. 4N patients were compared with the remaining stage 4 patients (non-4N), excluding those with missing metastatic site data. Results In all, 2,250 International Neuroblastoma Staging System stage 4 patients with complete data were identified, of whom 146 (6.5%) had 4N disease. For 4N patients, event-free survival (EFS; 5-year, 77% ± 4%) and overall survival (OS; 5-year, 85% ± 3%) were significantly better than EFS (5-year, 35% ± 1%) and OS (5-year, 42% ± 1%) for non-4N stage 4 patients (P < .001). 4N patients were more likely to be younger (P < .001) and have tumors with favorable characteristics, including absence of MYCN amplification (89% v 69%; P < .001). In a multivariable analysis, 4N disease remained a significant predictor of outcome (hazard ratio for non-4N v 4N: 3.40 for EFS and 3.69 for OS). Within subgroups defined by age at diagnosis and tumor MYCN status, 4N disease was significantly associated with improved outcomes. Conclusion 4N represents a subgroup with better outcome than that of other patients with metastatic disease. These findings suggest that the biology and treatment response of 4N tumors differ from other stage 4 tumors, and less intensive therapy should be considered for this cohort. Future exploration of biologic factors determining the pattern of metastatic spread is warranted. PMID:24663047

  11. Algebraic varieties in the Birkhoff strata of the Grassmannian Gr(2): Harrison cohomology and integrable systems

    NASA Astrophysics Data System (ADS)

    Konopelchenko, B. G.; Ortenzi, G.

    2011-11-01

    The local properties of the families of algebraic subsets Wg in the Birkhoff strata Σ2g of Gr(2) containing the hyperelliptic curves of genus g are studied. It is shown that the tangent spaces Tg for Wg are isomorphic to the linear spaces of 2-coboundaries. Particular subsets in Wg are described by the integrable dispersionless coupled KdV systems of hydrodynamical type defining a special class of 2-cocycles and 2-coboundaries in Tg. It is demonstrated that the blows-ups of such 2-cocycles and 2-coboundaries and gradient catastrophes for associated integrable systems are interrelated.

  12. Tetrabutylammonium cation in a homoleptic environment of borohydride ligands: [(n-Bu){sub 4}N][BH{sub 4}] and [(n-Bu){sub 4}N][Y(BH{sub 4}){sub 4}

    SciTech Connect

    Jaron, T.; Wegner, W.; Cyranski, M.K.; Dobrzycki, L.; Grochala, W.

    2012-07-15

    A novel solvent-free dual-cation organic-inorganic derivative, tetrabutylammonium yttrium borohydride (TBAYB), has been prepared for the first time and structurally characterized together with its organic precursor, tetrabutylammonium borohydride (TBAB). Both compounds crystallize in monoclinic unit cells (TBAYB: P2{sub 1}/c, TBAB: P2/c) and they contain [(n-Bu){sub 4}N]{sup +} in a homoleptic environment consisting of BH{sub 4}{sup -} ligands. Presence of large and lightweight Bu{sub 4}N{sup +} cations results in loose packing and low densities of both solids close to 1 g cm{sup -3}. TBAB melts at ca. 130 Degree-Sign C and it decomposes thermally above 160 Degree-Sign C while TBAYB melts at temperature as low as 78 Degree-Sign C, and the melt is stable over an appreciable temperature range of ca. 150 Degree-Sign C. The low melting point of TBAYB is the second lowest among derivatives of yttrium rendering this compound a new ionic liquid above 78 Degree-Sign C. - Graphical abstract: A novel organic-inorganic hybrid material for hydrogen storage, where (n-Bu){sub 4}N{sup +} cation is found in homoleptic environment of BH{sub 4}{sup -} ligands, was synthesised. Highlights: Black-Right-Pointing-Pointer Novel organic-inorganic hybrid material for hydrogen storage was synthesised. Black-Right-Pointing-Pointer (n-Bu){sub 4}N{sup +} cation is found in a homoleptic environment of BH{sub 4}{sup -} ligands. Black-Right-Pointing-Pointer TBAYB derivative is a novel ionic liquid with melting point of 78 Degree-Sign C..

  13. Interferon regulatory factor-8 modulates the development of tumour-induced CD11b+Gr-1+ myeloid cells.

    PubMed

    Stewart, Trina J; Greeneltch, Kristy M; Reid, Julia E; Liewehr, David J; Steinberg, Seth M; Liu, Kebin; Abrams, Scott I

    2009-09-01

    Tumour-induced myeloid-derived suppressor cells (MDSC) promote immune suppression and mediate tumour progression. However, the molecular basis for the generation of MDSC, which in mice co-express the CD11b(+) and Gr-1(+) cell surface markers remains unclear. Because CD11b(+)Gr-1(+) cells expand during progressive tumour growth, this suggests that tumour-induced events alter signalling pathways that affect normal myeloid cell development. Interferon regulatory factor-8 (IRF-8), a member of the IFN-gamma regulatory factor family, is essential for normal myelopoiesis. We therefore examined whether IRF-8 modulated tumour-induced CD11b(+)Gr-1(+) cell development or accumulation using both implantable (4T1) and transgenic (MMTV-PyMT) mouse models of mammary tumour growth. In the 4T1 model, both splenic and bone marrow-derived CD11b(+)Gr-1(+) cells of tumour-bearing mice displayed a marked reduction in IRF-8 expression compared to control populations. A causal link between IRF-8 expression and the emergence of tumour-induced CD11b(+)Gr-1(+) cells was explored in vivo using a double transgenic (dTg) mouse model designed to express transgenes for both IRF-8 and mammary carcinoma development. Despite the fact that tumour growth was unaffected, splenomegaly, as well as the frequencies and absolute numbers of CD11b(+)Gr-1(+) cells were significantly lower in dTg mice when compared with single transgenic tumour-bearing mice. Overall, these data reveal that IRF-8 plays an important role in tumour-induced development and/or accumulation of CD11b(+)Gr-1(+) cells, and establishes a molecular basis for the potential manipulation of these myeloid populations for cancer therapy. PMID:20196788

  14. High Resolution Magnetostratigraphy Susceptibility (MS) and Gamma Radiation (GR) Measurements from Three Coeval Upper Cretaceous Stratigraphic Sequences in Colorado: Testing MS and GR Variations Arising from Detrital Components in Variably Weathered Marine Sedimentary Rocks (Invited)

    NASA Astrophysics Data System (ADS)

    Ellwood, B. B.; Tomkin, J. H.; Wang, W.

    2010-12-01

    We have measured the magnetic susceptibility(MS) and gamma radiation (GR) for three Upper Cretaceous marine sedimentary sequences that span the Cenomanian-Turonian (C-T) boundary exposed as part of the Western Interior Seaway in Central Colorado. The purpose of this study was three fold: (1) to evaluate the combined potential of MS and GR as a correlation tool using well-studied sequences that have been previously correlated based on high-resolution lithostratigraphy, (2) to evaluate the effect of differential weathering on MS and GR values, and (3) to evaluate how their relationship with each other changes. This work includes sampling of the moderately weathered Global Boundary Stratotype Section and Point (GSSP) for the C-T boundary that is exposed in a railroad cut near Pueblo, CO. A nearby (~1 km) coeval section in an old road cut, where weathering is pronounced, was also sampled, as was fresh material through the C-T boundary interval from a core drilled ~40 km to the west of Pueblo (the USGS#1 Portland Core). MS was measured in the laboratory at LSU on samples collected at ~5 cm intervals from each of these sequences. GR was measured in the field at ~5 cm intervals on the two outcrop sequences, using a portable GR spectrometer. In addition, the GR also was measured on samples collected for MS measurement, using a laboratory-based Germanium detector. It is argued that both MS and GR data sets are controlled by detrital fluxes into the marine environment, although the effect of weathering, if any, on these parameters when exposed in outcrop, is not well documented. In addition, these parameters are controlled by different detrital components that may be derived from different sources, or be differentially concentrated within the marine system. Here we report the results of a number of experiments designed to evaluate how the MS and GR data sets co-vary, and to test their usefulness as correlation tools in stratigraphically. We have also examined the effects of

  15. Metallic transport and large anomalous Hall effect at room temperature in ferrimagnetic Mn{sub 4}N epitaxial thin film

    SciTech Connect

    Shen, Xi; Shigematsu, Kei; Chikamatsu, Akira Fukumura, Tomoteru; Hirose, Yasushi; Hasegawa, Tetsuya

    2014-08-18

    We report the electrical transport properties of ferrimagnetic Mn{sub 4}N (001) epitaxial thin films grown by pulsed laser deposition on MgO (001) substrates. The Mn{sub 4}N thin films were tetragonally distorted with a ratio of out-of-plane to in-plane lattice constants of 0.987 and showed perpendicular magnetic anisotropy with an effective magnetic anisotropy constant of 0.16 MJ/m{sup 3}, which is comparable with that of a recently reported molecular-beam-epitaxy-grown film. The thin films exhibited metallic transport with a room temperature resistivity of 125 μΩ cm in addition to a large anomalous Hall effect with a Hall angle tangent of 0.023.

  16. Solid-state photochemistry as a formation mechanism for Titan's stratospheric C4N2 ice clouds

    NASA Astrophysics Data System (ADS)

    Anderson, C. M.; Samuelson, R. E.; Yung, Y. L.; McLain, J. L.

    2016-04-01

    We propose that C4N2 ice clouds observed in Titan's springtime polar stratosphere arise due to solid-state photochemistry occurring within extant ice cloud particles of HCN-HC3N mixtures. This formation process resembles the halogen-induced ice particle surface chemistry that leads to condensed nitric acid trihydrate (NAT) particles and ozone depletion in Earth's polar stratosphere. As our analysis of the Cassini Composite Infrared Spectrometer 478 cm-1 ice emission feature demonstrates, this solid-state photochemistry mechanism eliminates the need for the relatively high C4N2 saturation vapor pressures required (even though they are not observed) when the ice is produced through the usual procedure of direct condensation from the vapor.

  17. The investigation of the electrical properties of Fe3O4/n-Si heterojunctions in a wide temperature range.

    PubMed

    Deniz, Ali Rıza; Çaldıran, Zakir; Metin, Önder; Meral, Kadem; Aydoğan, Şakir

    2016-07-01

    Monodisperse 8nm Fe3O4 nanoparticles (NPs) were synthesized by the thermal decomposition of iron(III) acetylacetonate in oleylamine and then were deposited onto n-type silicon wafer having the Al ohmic contact. Next, the morphology of the Fe3O4 NPs were characterized by using TEM and XRD. The optical properties of Fe3O4 NPs film was studied by UV-Vis spectroscopoy and its band gap was calculated to be 2.16eV. Au circle contacts with 7.85×10(-3)cm(2) area were provided on the Fe3O4 film via evaporation at 10(-5)Torr and the Au/Fe3O4 NPs/n-Si/Al heterojunction device were fabricated. The temperature-dependent junction parameters of Au/Fe3O4/n-Si/Al device including ideality factor, barrier height and series resistance were calculated by using the I-V characteristics in a wide temperature range of 40-300K. The results revealed that the ideality factor and series resistance increased by the decreasing temperature while the barrier height decreases. The Richardson constant of Au/Fe3O4/n-Si/Al device was calculated to be 2.17A/K(2)cm(2) from the I-V characteristics. The temperature dependence of Au/Fe3O4/n-Si/Al heterojunction device showed a double Gaussian distribution, which is caused by the inhomogeneities characteristics of Fe3O4/n-Si heterojunction.

  18. Spinel ZnCo2O4/N-doped carbon nanotube composite: A high active oxygen reduction reaction electrocatalyst

    NASA Astrophysics Data System (ADS)

    Pu, Zonghua; Liu, Qian; Tang, Chun; Asiri, Abdullah M.; Qusti, Abdullah H.; Al-Youbi, Abdulrahman O.; Sun, Xuping

    2014-07-01

    In this communication, we report on the solvothermal preparation of spinel ZnCo2O4/N-doped carbon nanotube (ZnCo2O4/NCNT) composite. As a novel oxygen reduction reaction (ORR) electrocatalyst, the ZnCo2O4/NCNT composite shows high activity via a four-electron pathway in alkaline solution. Such catalyst also exhibits superior methanol tolerance ability and durability over commercial Pt/C catalyst.

  19. DDX6 transfers P-TEFb kinase to the AF4/AF4N (AFF1) super elongation complex

    PubMed Central

    Mück, Fabian; Bracharz, Silvia; Marschalek, Rolf

    2016-01-01

    AF4/AFF1 and AF5/AFF4 are both backbones for the assembly of “super elongation complexes” (SECs) that exert 2 distinct functions after the recruitment of P-TEFb from the 7SK snRNP: (1) initiation and elongation of RNA polymerase II gene transcription, and (2) modification of transcribed gene regions by distinct histone methylation patterns. In this study we aimed to investigate one of the initial steps, namely how P-TEFb is transferred from 7SK snRNPs to the SECs. In particular, we were interested in the role of DDX6 that we have recently identified as part of the AF4 complex. DDX6 is an evolutionarily conserved member of the DEAD-box RNA helicase family that is known to control miRNA and mRNA biology (translation, storage and degradation). Overexpressed DDX6 is associated with different cancer types and with c-Myc protein overexpression. We could demonstrate that DDX6 binds to 7SK snRNA and causes the release and transfer of P-TEFb to the AF4/AF4N SEC. DDX6 also binds stably to AF4 and AF4N as demonstrated by GST pull-down and co-immunoprecipitation experiments. As a consequence, overexpression of either AF4/AF4N or DDX6 resulted in a strong increase of mRNA production (5-6 fold), while their simultaneous expression increased the cellular mRNA production by 11-fold. Conversely, the corresponding knockdown of DDX6 decreased mRNA production by 70%. In conclusion, AF4/AF4N and DDX6 represent key molecules for the elongation process of gene transcription and a model will be proposed for the hand-over process of P-TEFb to SECs. PMID:27679741

  20. Etch characteristics of magnetic tunnel junction materials using bias pulsing in the CH4/N2O inductively coupled plasma.

    PubMed

    Jeon, Min Hwan; Youn, Ji Youn; Yang, Kyung Chae; Yun, Deok Hyun; Lee, Du Yeong; Shim, Tae Hun; Park, Jea Gun; Yeom, Geun Young

    2014-12-01

    The etch characteristics of magnetic tunneling junction (MTJ) related materials such as CoFeB, MgO, FePt, Ru, and W as hard mask have been investigated as functions of rf pulse biasing, substrate heating, and CH4/N2O gas combination in an inductively coupled plasma system. When CH4/N2O gas ratio was varied, at CH4/N2O gas ratio of 2:1, not only the highest etch rates but also the highest etch selectivity over W could be obtained. By increasing the substrate temperature, the linear increase of both the etch rates of MTJ materials and the etch selectivity over W could be obtained. The use of the rf pulse biasing improved the etch selectivity of the MTJ materials over hard mask such as W further. The surface roughness and residual thickness remaining on the etched surface of the CoFeB were also decreased by using rf pulse biasing and with the decrease of rf duty percentage. The improvement of etch characteristics by substrate heating and rf pulse biasing was possibly related to the formation of more stable and volatile etch compounds and the removal of chemically reacted compounds more easily on the etched CoFeB surface. Highly selective etching of MTJ materials over the hard mask could be obtained by using the rf pulse biasing of 30% of duty ratio and by increasing the substrate temperature to 200 degrees C in the CH4/N2O (2:1) plasmas. PMID:25971096

  1. Stereotactic body radiotherapy for T3 and T4N0M0 non–small cell lung cancer

    PubMed Central

    Eriguchi, Takahisa; Takeda, Atsuya; Sanuki, Naoko; Nishimura, Shuichi; Takagawa, Yoshiaki; Enomoto, Tatsuji; Saeki, Noriyuki; Yashiro, Kae; Mizuno, Tomikazu; Aoki, Yousuke; Oku, Yohei; Yokosuka, Tetsuya; Shigematsu, Naoyuki

    2016-01-01

    To evaluate the outcomes and feasibility of stereotactic body radiotherapy (SBRT) for cT3 and cT4N0M0 non–small cell lung cancer (NSCLC), 25 patients with localized primary NSCLC diagnosed as cT3 or cT4N0M0, given SBRT between May 2005 and July 2013, were analyzed. All patients had inoperable tumors. The major reasons for tumors being unresectable were insufficient respiratory function for curative resection, advanced age (>80 years old) or technically inoperable due to invasion into critical organs. The median patient age was 79 years (range; 60–86). The median follow-up duration was 25 months (range: 5–100 months). The 2-year overall survival rates for T3 and T4 were 57% and 69%, respectively. The 2-year local control rates for T3 and T4 were 91% and 68%, respectively. As for toxicities, Grade 0–1, Grade 2 and Grade 3 radiation pneumonitis occurred in 23, 1 and 1 patient, respectively. No other acute or symptomatic late toxicities were reported. Thirteen patients who had no local, mediastinal or intrapulmonary progression at one year after SBRT underwent pulmonary function testing. The median variation in pre-SBRT and post-SBRT forced expiratory volume in 1 s (FEV1) values was –0.1 (–0.8–0.8). This variation was not statistically significant (P = 0.56). Forced vital capacity (FVC), vital capacity (VC), %VC and %FEV1 also showed no significant differences. SBRT for cT3 and cT4N0M0 NSCLC was both effective and feasible. Considering the favorable survival and low morbidity rate, SBRT is a potential treatment option for cT3 and cT4N0M0 NSCLC. PMID:26983978

  2. DDX6 transfers P-TEFb kinase to the AF4/AF4N (AFF1) super elongation complex.

    PubMed

    Mück, Fabian; Bracharz, Silvia; Marschalek, Rolf

    2016-01-01

    AF4/AFF1 and AF5/AFF4 are both backbones for the assembly of "super elongation complexes" (SECs) that exert 2 distinct functions after the recruitment of P-TEFb from the 7SK snRNP: (1) initiation and elongation of RNA polymerase II gene transcription, and (2) modification of transcribed gene regions by distinct histone methylation patterns. In this study we aimed to investigate one of the initial steps, namely how P-TEFb is transferred from 7SK snRNPs to the SECs. In particular, we were interested in the role of DDX6 that we have recently identified as part of the AF4 complex. DDX6 is an evolutionarily conserved member of the DEAD-box RNA helicase family that is known to control miRNA and mRNA biology (translation, storage and degradation). Overexpressed DDX6 is associated with different cancer types and with c-Myc protein overexpression. We could demonstrate that DDX6 binds to 7SK snRNA and causes the release and transfer of P-TEFb to the AF4/AF4N SEC. DDX6 also binds stably to AF4 and AF4N as demonstrated by GST pull-down and co-immunoprecipitation experiments. As a consequence, overexpression of either AF4/AF4N or DDX6 resulted in a strong increase of mRNA production (5-6 fold), while their simultaneous expression increased the cellular mRNA production by 11-fold. Conversely, the corresponding knockdown of DDX6 decreased mRNA production by 70%. In conclusion, AF4/AF4N and DDX6 represent key molecules for the elongation process of gene transcription and a model will be proposed for the hand-over process of P-TEFb to SECs. PMID:27679741

  3. Growth and electrical properties on NLO crystal: 4-N,N-dimethylamino 4′-N′-methylstilbazolium iodide

    SciTech Connect

    Kumar, M. Krishna Sudhahar, S. Kumar, R. Mohan

    2014-04-24

    4-N,N-Dimethylamino-4′-N′-methylstilbazolium tosylate single crystals were grown by solution crystal growth method. The cell parameters of grown crystal have been estimated using single crystal-X-ray diffraction analysis. The variation of real (´ε) and imaginary (´ε) part of dielectric constants and dielectric loss were observed for different frequencies and temperatures. The ac and dc electrical conductivities and activation energy were determined for DMSI crystal using dielectric studies.

  4. Stereotactic body radiotherapy for T3 and T4N0M0 non-small cell lung cancer.

    PubMed

    Eriguchi, Takahisa; Takeda, Atsuya; Sanuki, Naoko; Nishimura, Shuichi; Takagawa, Yoshiaki; Enomoto, Tatsuji; Saeki, Noriyuki; Yashiro, Kae; Mizuno, Tomikazu; Aoki, Yousuke; Oku, Yohei; Yokosuka, Tetsuya; Shigematsu, Naoyuki

    2016-06-01

    To evaluate the outcomes and feasibility of stereotactic body radiotherapy (SBRT) for cT3 and cT4N0M0 non-small cell lung cancer (NSCLC), 25 patients with localized primary NSCLC diagnosed as cT3 or cT4N0M0, given SBRT between May 2005 and July 2013, were analyzed. All patients had inoperable tumors. The major reasons for tumors being unresectable were insufficient respiratory function for curative resection, advanced age (>80 years old) or technically inoperable due to invasion into critical organs. The median patient age was 79 years (range; 60-86). The median follow-up duration was 25 months (range: 5-100 months). The 2-year overall survival rates for T3 and T4 were 57% and 69%, respectively. The 2-year local control rates for T3 and T4 were 91% and 68%, respectively. As for toxicities, Grade 0-1, Grade 2 and Grade 3 radiation pneumonitis occurred in 23, 1 and 1 patient, respectively. No other acute or symptomatic late toxicities were reported. Thirteen patients who had no local, mediastinal or intrapulmonary progression at one year after SBRT underwent pulmonary function testing. The median variation in pre-SBRT and post-SBRT forced expiratory volume in 1 s (FEV1) values was -0.1 (-0.8-0.8). This variation was not statistically significant (P = 0.56). Forced vital capacity (FVC), vital capacity (VC), %VC and %FEV1 also showed no significant differences. SBRT for cT3 and cT4N0M0 NSCLC was both effective and feasible. Considering the favorable survival and low morbidity rate, SBRT is a potential treatment option for cT3 and cT4N0M0 NSCLC. PMID:26983978

  5. DDX6 transfers P-TEFb kinase to the AF4/AF4N (AFF1) super elongation complex

    PubMed Central

    Mück, Fabian; Bracharz, Silvia; Marschalek, Rolf

    2016-01-01

    AF4/AFF1 and AF5/AFF4 are both backbones for the assembly of “super elongation complexes” (SECs) that exert 2 distinct functions after the recruitment of P-TEFb from the 7SK snRNP: (1) initiation and elongation of RNA polymerase II gene transcription, and (2) modification of transcribed gene regions by distinct histone methylation patterns. In this study we aimed to investigate one of the initial steps, namely how P-TEFb is transferred from 7SK snRNPs to the SECs. In particular, we were interested in the role of DDX6 that we have recently identified as part of the AF4 complex. DDX6 is an evolutionarily conserved member of the DEAD-box RNA helicase family that is known to control miRNA and mRNA biology (translation, storage and degradation). Overexpressed DDX6 is associated with different cancer types and with c-Myc protein overexpression. We could demonstrate that DDX6 binds to 7SK snRNA and causes the release and transfer of P-TEFb to the AF4/AF4N SEC. DDX6 also binds stably to AF4 and AF4N as demonstrated by GST pull-down and co-immunoprecipitation experiments. As a consequence, overexpression of either AF4/AF4N or DDX6 resulted in a strong increase of mRNA production (5-6 fold), while their simultaneous expression increased the cellular mRNA production by 11-fold. Conversely, the corresponding knockdown of DDX6 decreased mRNA production by 70%. In conclusion, AF4/AF4N and DDX6 represent key molecules for the elongation process of gene transcription and a model will be proposed for the hand-over process of P-TEFb to SECs.

  6. Quantitative Analysis of Seismicity Before Large Taiwanese Earthquakes Using the G-R Law

    NASA Astrophysics Data System (ADS)

    Li, H.-C.; Chang, C.-H.; Chen, C.-C.

    2016-01-01

    Seismicity has been identified as an example of a natural, nonlinear system for which the distribution of frequency and event size follow a power law called the "Gutenberg-Richter (G-R) law." The parameters of the G-R law, namely b- and a-values, have been widely used in many studies about seismic hazards, earthquake forecasting models, and other related topics. However, the plausibility of the power law model and applicability of parameters were mainly verified by statistical error σ of the b-value, the effectiveness of which is still doubtful. In this research, we used a newly defined p value developed by Clauset et al. ( Power- Law Distributions in Empirical Data, SIAM Rev. 51, 661-703, 2009) instead of the statistical error σ of the b-value and verified its effectiveness as a plausibility index of the power-law model. Furthermore, we also verified the effectiveness of K-S statistics as a goodness-of-fit test in estimating the crucial parameter M_{c} of the power-law model.

  7. Nonlinear elastic effects on the energy flux deviation of ultrasonic waves in gr/ep composites

    NASA Technical Reports Server (NTRS)

    Prosser, William H.; Kriz, R. D.; Fitting, Dale W.

    1992-01-01

    The effects of nonlinear elasticity on energy flux deviation in undirectional gr/ep composites are examined. The shift in the flux deviation is modeled using acoustoelasticity theory and the second- and third-order elastic stiffness coefficients for T300/5208 gr/ep. Two conditions of applied uniaxial stress are considered. In the first case, the direction of applied uniaxial stress was along the fiber axis (x3), while in the second case it was perpendicular to the fiber axis along the laminate stacking direction (x1). For both conditions, the change in the energy flux deviation angle from the condition of zero applied stress is computed over the range of propagation directions of 0 to 60 deg from the fiber axis at two-degree intervals. A positive flux deviation angle implies the energy deviates away from the fiber direction toward the x1 axis, while a negative deviation means that the energy deviates toward the fibers. Over this range of fiber orientation angles, the energy of the quasi-longitudinal and pure mode transverse waves deviates toward the fibers, while that of the quasi-transverse mode deviates away from the fibers.

  8. GrACE-PPM: A distributed dynamic adaptive mesh CFD Environment for accelerated inhomogeneous compressible flows

    NASA Astrophysics Data System (ADS)

    Zhang, Shuang; Parashar, Manish; Zabusky, Norman

    2001-11-01

    We merge the PPM compressible algorithm (VH-1 (M. Parashar, Grid Adaptive Computational Engine. 2001. http://www.caip.rutgers.edu/ parashar/TASSL/Projects/GrACE/Gmain.html)) with the new Grid Adaptive Computation Engine (GrACE ( J. M. Blondin and J. Hawley, Virginia Hydrodynamics Code. http://wonka.physics.ncsu.edu/pub/VH-1/index.html)). The latter environment uses the Berger-Oliger AMR algorithm and has many high-performance computation features such as data parallelism, data and computation locality, etc. We discuss the performance (scaling) resulting from examining the space of four parameters: top coarse level resolution; number of refinement levels; number of processors; duration of calculation. We validate the new code by applying it to the 2D shock-curtain interaction problem (N. J. Zabusky and S. Zhang. "Shock - planar curtain interactions in 2D: Emergence of vortex double layers, vortex projectiles and decaying stratified turbulence." Revised submitted Physics of Fluids, July, 2001.). We discuss the visualization and quantification of AMR data sets.

  9. Friction Stir Welding of GR-Cop 84 for Combustion Chamber Liners

    NASA Technical Reports Server (NTRS)

    Russell, Carolyn K.; Carter, Robert; Ellis, David L.; Goudy, Richard

    2004-01-01

    GRCop-84 is a copper-chromium-niobium alloy developed by the Glenn Research Center for liquid rocket engine combustion chamber liners. GRCop-84 exhibits superior properties over conventional copper-base alloys in a liquid hydrogen-oxygen operating environment. The Next Generation Launch Technology program has funded a program to demonstrate scale-up production capabilities of GR-Cop 84 to levels suitable for main combustion chamber production for the prototype rocket engine. This paper describes a novel method of manufacturing the main combustion chamber liner. The process consists of several steps: extrude the GR-Cop 84 powder into billets, roll the billets into plates, bump form the plates into cylinder halves and friction stir weld the halves into a cylinder. The cylinder is then metal spun formed to near net liner dimensions followed by finish machining to the final configuration. This paper describes the friction stir weld process development including tooling and non-destructive inspection techniques, culminating in the successful production of a liner preform completed through spin forming.

  10. [Mexican medicinal plants and Grüninger's diet. Documentation No.25].

    PubMed

    Deplazes, G; Hauser, S P

    1990-05-29

    A decoction is prepared from 14 Mexican medicinal plants. This phytotherapy is supplemented by a special diet ('food with a high nutritional value') and nutritional supplements such as lactoferment, enzyme preparations (e.g. Wobenzym), co-enzymes (e.g. Becozym forte) Ossopulvit, vitamin C, iron preparations and raw melasses. The following indications are mentioned: all stages of cancer, following surgery, during radiotherapy or chemotherapy in order to alleviate side effects and stimulate the immune system and hematopoiesis, detoxification in all other diseases. The initial fasting period is followed by a diet, phytotherapy and the ingestion of nutritional supplements. The only side effects are caused by tumour degradation products as a result of excessively rapid tumour degradation. The documentation brochure costs Fr. 30.-. The patient pays what he likes for the tea bag of a cure. F.A. Grüninger is a chemist living in the Bernese Oberland (Switzerland). He spends most of his time in Mexico, where he himself collects the individual plants. According to Grüninger, cancer is an intoxication of the entire body as a result of an inappropriate diet (demineralized, poor in cellulose, high in hormone levels). The intoxication in counteracted by fasting, phytotherapy and dietary measures. Only subjective statements are available about the Mexican medicinal plants. Toxicity studies in rats revealed no signs of toxicity. There are no preclinical or clinical data in man. PMID:2349430

  11. [Mexican medicinal plants and Grüninger's diet. Documentation No.25].

    PubMed

    Deplazes, G; Hauser, S P

    1990-05-29

    A decoction is prepared from 14 Mexican medicinal plants. This phytotherapy is supplemented by a special diet ('food with a high nutritional value') and nutritional supplements such as lactoferment, enzyme preparations (e.g. Wobenzym), co-enzymes (e.g. Becozym forte) Ossopulvit, vitamin C, iron preparations and raw melasses. The following indications are mentioned: all stages of cancer, following surgery, during radiotherapy or chemotherapy in order to alleviate side effects and stimulate the immune system and hematopoiesis, detoxification in all other diseases. The initial fasting period is followed by a diet, phytotherapy and the ingestion of nutritional supplements. The only side effects are caused by tumour degradation products as a result of excessively rapid tumour degradation. The documentation brochure costs Fr. 30.-. The patient pays what he likes for the tea bag of a cure. F.A. Grüninger is a chemist living in the Bernese Oberland (Switzerland). He spends most of his time in Mexico, where he himself collects the individual plants. According to Grüninger, cancer is an intoxication of the entire body as a result of an inappropriate diet (demineralized, poor in cellulose, high in hormone levels). The intoxication in counteracted by fasting, phytotherapy and dietary measures. Only subjective statements are available about the Mexican medicinal plants. Toxicity studies in rats revealed no signs of toxicity. There are no preclinical or clinical data in man.

  12. Contribution of recovery mechanisms of microstructure during long-term creep of Gr.91 steels

    NASA Astrophysics Data System (ADS)

    Ghassemi-Armaki, H.; Chen, R. P.; Maruyama, K.; Igarashi, M.

    2013-02-01

    Creep rupture life and microstructural degradation have been studied in two heats of Gr.91 steels. The coarsening of subgrains and precipitates, mainly M23C6 and MX, has been evaluated during static aging and creep. Hardness of head (static aging) and gauge (creep) portions of crept samples were measured to know their relation with microstructural degradation during long-term exposure. The correlation between subgrain size and spacing of precipitates and hardness has been equated. As an example, there is a close correlation between hardness value and inverse subgrains size in Gr.91 steels, regardless of aging or creep conditions. The appearance of three recovery mechanisms was found during long-term creep, namely: strain-induced recovery, pure static recovery and strain-assisted static recovery. By equated correlations between subgrain size, precipitates and hardness, the contribution of three recovery mechanisms to subgrain coarsening and hardness drop were calculated for two creep conditions at 700 °C in long-term creep region, where breakdown of creep strength has happen. The calculated data accord well with experimental data obtained from aged and crept samples. The contribution of static recovery to the subgrain coarsening and consequent hardness drop during long-term creep increases with increasing creep time. The significant contribution of both static recovery mechanisms can result in the breakdown of creep strength in long-term creep region.

  13. GR718- Radiation-Tolerant 18x SpaceWire Router

    NASA Astrophysics Data System (ADS)

    Ekergaren, Jonas; Habinc, Sandi; Johansson, Fredrik; Sturesson, Fredrik; Simlastik, Martin; Hernandez, Francisco; Redant, Steven; Stinkens, Kurt; Thys, Geert; Das Arul Mahesh, Jagadeesa; Suess, Martin

    2015-09-01

    GR718 is a radiation tolerant 18 port standalone SpaceWire router component that has been developed by Cobham Gaisler together with IMEC (BE), in an activity initiated by the European Space Agency under ESTEC contract 4000105402/12/NL/Cbi. Out of the 18 SpaceWire ports, 16 use on-chip LVDS transceivers, and two use LVTTL signaling. Included also is the mandatory configuration port, as well as an internal port for system level testing. All ports are capable of operating in 200 Mbit/s. UART and JTAG interfaces, that gives access to the on-chip AMBA AHB bus, are provided for configuration and debugging. SPI and GPIO interfaces are accessible through the configuration port, which allows SPI devices to be accessed and general purpose signaling to be performed through RMAP commands. In addition to the mandatory features in the current ECSS SpaceWire standard, GR718 supports group adaptive routing for path addresses, and packet distribution. It also includes support for the incoming SpaceWire standard revision 1 (ECSS-E-ST-50-12C Rev.1), the SpaceWire-D protocol, and the SpaceWire Plug-and-Play protocol currently being developed for ECSS. The technology used is UMC 180 nm, using the DARE library from IMEC, and the package is a 256 pin CQFP. A development board for evaluation and software development has been manufactured as well.

  14. Purification and characterization of thermostable alpha-galactosidase from Aspergillus terreus (GR).

    PubMed

    Shankar, S K; Dhananjay, S K; Mulimani, V H

    2009-02-01

    An extracellular thermostable alpha-galactosidase producing Aspergillus terreus (GR) strain was isolated from soil sample using guar gum as sole source of carbon. It was purified to apparent homogeneity by acetone precipitation, gel filtration followed by DEAE-Sephacel chromatographic step. The purified enzyme showed a single band after sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weight of the purified enzyme after SDS-PAGE was 108 kDa. The enzyme showed optimum pH and temperature of 5.0 and 65 degrees C, respectively, for artificial substrate pNPalphaGal. alpha-Galactosidase from A. terreus (GR) is found to be thermostable, as it was not inactivated after heating at 65 degrees C for 40 min. The K (m) for pNPalphaGal, oNPalphaGal, raffinose, and stachyose are 0.1, 0.28, 0.42, and 0.33 mM, respectively. Inhibitors such as 1,10-phenanthroline, phenylmethylsulfonyl fluoride, ethylenediaminetetraacetic acid, mercaptoethanol, and urea have no effect, whereas N-bromosuccinamide inhibited enzyme activity by 100%. Among metal ions tested, Mg(2+), Ni(2+), Ca(2+), Co(2+), and Mn(2+) had no effect on enzyme activity, but Ag(+), Hg(2+), and Cu(2+) have inhibited complete activity.

  15. Novel insights into the neuroendocrine control of inflammation: the role of GR and PARP1

    PubMed Central

    Aprile-Garcia, Fernando; Antunica-Noguerol, María; Budziñski, Maia Ludmila; Liberman, Ana C; Arzt, Eduardo

    2013-01-01

    Inflammatory responses are elicited after injury, involving release of inflammatory mediators that ultimately lead, at the molecular level, to the activation of specific transcription factors (TFs; mainly activator protein 1 and nuclear factor-κB). These TFs propagate inflammation by inducing the expression of cytokines and chemokines. The neuroendocrine system has a determinant role in the maintenance of homeostasis, to avoid exacerbated inflammatory responses. Glucocorticoids (GCs) are the key neuroendocrine regulators of the inflammatory response. In this study, we describe the molecular mechanisms involved in the interplay between inflammatory cytokines, the neuroendocrine axis and GCs necessary for the control of inflammation. Targeting and modulation of the glucocorticoid receptor (GR) and its activity is a common therapeutic strategy to reduce pathological signaling. Poly (ADP-ribose) polymerase 1 (PARP1) is an enzyme that catalyzes the addition of PAR on target proteins, a post-translational modification termed PARylation. PARP1 has a central role in transcriptional regulation of inflammatory mediators, both in neuroendocrine tumors and in CNS cells. It is also involved in modulation of several nuclear receptors. Therefore, PARP1 and GR share common inflammatory pathways with antagonic roles in the control of inflammatory processes, which are crucial for the effective maintenance of homeostasis. PMID:24243533

  16. Triboelectric charging of volcanic ash from Grímsvötn

    NASA Astrophysics Data System (ADS)

    Houghton, Isobel; Aplin, Karen; Nicoll, Keri

    2013-04-01

    Volcanic ash is known to charge electrically, producing some of the most spectacular displays of lightning in nature. Triboelectric charging is one mechanism associated with volcanic plume electrification. Previous theoretical work on triboelectric charging of single-material particle systems has shown that the charging is likely to be determined by the number size distribution (Lacks and Levandovsky, 2007). Here we investigate triboelectric charging of a sample of ash from the Grímsvötn eruption in 2011 using a specially designed apparatus. Ash is released to fall under gravity through a screened metal cylinder and into an isolated Faraday cup. A sensitive electrometer is used to measure the voltage change associated with the charge on the ash. The release mechanism has been designed to facilitate only self-charging of the ash, as is expected in the atmospheric plume. Using geological sieves to separate the sample into different size fractions, we were able to create artificial size distributions to investigate the effects of changing the number size distribution. We find that for a sample with a narrow range of particle sizes, the Faraday cup voltage change is much smaller than for a sample with a wide range of particle sizes, in agreement with theory. These results demonstrate that self-charging of ash through triboelectrification is likely, supporting both a frictional origin for the sustained lightning observed during the Grímsvötn eruption, and other observations of self-charging in a plume distant from the source.

  17. airGR: a suite of lumped hydrological models in an R-package

    NASA Astrophysics Data System (ADS)

    Coron, Laurent; Perrin, Charles; Delaigue, Olivier; Andréassian, Vazken; Thirel, Guillaume

    2016-04-01

    Lumped hydrological models are useful and convenient tools for research, engineering and educational purposes. They propose catchment-scale representations of the precipitation-discharge relationship. Thanks to their limited data requirements, they can be easily implemented and run. With such models, it is possible to simulate a number of hydrological key processes over the catchment with limited structural and parametric complexity, typically evapotranspiration, runoff, underground losses, etc. The Hydrology Group at Irstea (Antony) has been developing a suite of rainfall-runoff models over the past 30 years with the main objectives of designing models as efficient as possible in terms of streamflow simulation, applicable to a wide range of catchments and having low data requirements. This resulted in a suite of models running at different time steps (from hourly to annual) applicable for various issues including water balance estimation, forecasting, simulation of impacts and scenario testing. Recently, Irstea has developed an easy-to-use R-package (R Core Team, 2015), called airGR, to make these models widely available. It includes: - the water balance annual GR1A (Mouehli et al., 2006), - the monthly GR2M (Mouehli, 2003) models, - three versions of the daily model, namely GR4J (Perrin et al., 2003), GR5J (Le Moine, 2008) and GR6J (Pushpalatha et al., 2011), - the hourly GR4H model (Mathevet, 2005), - a degree-day snow module CemaNeige (Valéry et al., 2014). The airGR package has been designed to facilitate the use by non-expert users and allow the addition of evaluation criteria, models or calibration algorithms selected by the end-user. Each model core is coded in FORTRAN to ensure low computational time. The other package functions (i.e. mainly the calibration algorithm and the efficiency criteria) are coded in R. The package is already used for educational purposes. The presentation will detail the main functionalities of the package and present a case

  18. The first quaternary lanthanide(III) nitride iodides: Na M4N 2I 7 ( M=La-Nd)

    NASA Astrophysics Data System (ADS)

    Schurz, Christian M.; Schleid, Thomas

    2010-10-01

    In attempts to synthesize lanthanide(III) nitride iodides with the formula M2NI 3 ( M=La-Nd), moisture-sensitive single crystals of the first quaternary sodium lanthanide(III) nitride iodides Na M4N 2I 7 (orthorhombic, Pna2 1; Z=4; a=1391-1401, b=1086-1094, c=1186-1211 pm) could be obtained. The dominating structural features are {[}∞1 chains of trans-edge linked [N M4] 9+ tetrahedra, which run parallel to the polar 2 1-axis [001]. Between the chains, direct bonding via special iodide anions generates cages, in which isolated [NaI 6] 5- octahedra are embedded. The IR spectrum of NaLa 4N 2I 7 recorded from 100 to 1000 cm -1 shows main bands at υ=337, 373 and 489 cm -1. With decreasing radii of the lanthanide trications these bands, which can be assigned as an influence of the vibrations of the condensed [N M4] 9+ tetrahedra, are shifted toward higher frequencies for the Na M4N 2I 7 series ( M=La-Nd), following the lanthanide contraction.

  19. Characterization of an H4N2 Influenza Virus from Quails with a Multibasic Motif in the Hemagglutinin Cleavage Site

    PubMed Central

    Wong, Sook-San; Yoon, Sun-Woo; Zanin, Mark; Song, Min-Suk; Oshansky, Christine; Zaraket, Hassan; Sonnberg, Stephanie; Rubrum, Adam; Seiler, Patrick; Ferguson, Angela; Krauss, Scott; Cardona, Carol; Webby, Richard J.; Crossley, Beate

    2014-01-01

    The cleavage motif in the hemagglutinin (HA) protein of highly pathogenic H5 and H7 subtypes of avian influenza viruses is characterized by a peptide insertion or a multibasic cleavage site (MBCS). Here, we isolated an H4N2 virus from quails (Quail/CA12) with two additional arginines in the HA cleavage site, PEKRRTR/G, forming an MBCS-like motif. Quail/CA12 is a reassortant virus with the HA and neuraminidase (NA) gene most similar to a duck-isolated H4N2 virus, PD/CA06 with a monobasic HA cleavage site. Quail/CA12 required exogenous trypsin for efficient growth in culture and caused no clinical illness in infected chickens. Quail/CA12 had high binding preference for α2,6-linked sialic acids and showed higher replication and transmission ability in chickens and quails than PD/CA06. Although the H4N2 virus remained low pathogenic, these data suggests that the acquisition of MBCS in the field is not restricted to H5 or H7 subtypes. PMID:25151061

  20. Efficient hypoxic activation of the anticancer agent AQ4N by CYP2S1 and CYP2W1.

    PubMed

    Nishida, Clinton R; Lee, Melody; de Montellano, Paul R Ortiz

    2010-09-01

    AQ4N [1,4-bis{[2-(dimethylamino-N-oxide)ethyl]amino}-5,8-dihydroxyanthracene-9,10-dione], a prodrug with two dimethylamino N-oxide groups, is converted to the topoisomerase II inhibitor AQ4 [1,4-bis{[2-(dimethylamino)ethyl]amino}-5,8-dihydroxy-anthracene-9,10-dione] by reduction of the N-oxides to dimethylamino substituents. Earlier studies showed that several drug-metabolizing cytochrome P450 (P450) enzymes can catalyze this reductive reaction under hypoxic conditions comparable with those in solid tumors. CYP2S1 and CYP2W1, two extrahepatic P450 enzymes identified from the human genome whose functions are unknown, are expressed in hypoxic tumor cells at much higher levels than in normal tissue. Here, we demonstrate that CYP2S1, contrary to a published report (Mol Pharmacol 76:1031-1043, 2009), is efficiently reduced by NADPH-P450 reductase. Most importantly, both CYP2S1 and CYP2W1 are better catalysts for the reductive activation of AQ4N to AQ4 than all previously examined P450 enzymes. The overexpression of CYP2S1 and CYP2W1 in tumor tissues, together with their high catalytic activities for AQ4N activation, suggests that they may be exploited for the localized activation of anticancer prodrugs.

  1. Enhanced decolorization and biodegradation of textile azo dye Scarlet R by using developed microbial consortium-GR.

    PubMed

    Saratale, R G; Saratale, G D; Kalyani, D C; Chang, J S; Govindwar, S P

    2009-05-01

    A developed consortium-GR, consisting of Proteus vulgaris NCIM-2027 (PV) and Micrococcus glutamicus NCIM-2168 (MG), completely decolorized an azo dye Scarlet R under static anoxic condition with an average decolorization rate of 16,666 microg h(-1); which is much faster than that of the pure cultures (PV, 3571 microg h(-1); MG, 2500 microg h(-1)). Consortium-GR gave best decolorization performance with nearly complete mineralization of Scarlet R (over 90% TOC and COD reduction) within 3h, much shorter relative to the individual strains. Induction in the riboflavin reductase and NADH-DCIP reductase was observed in the consortium, suggesting the involvement of these enzymes during the fast decolorization process. The FTIR and GC-MS analysis showed that 1,4-benzenediamine was formed during decolorization/degradation of Scarlet R by consortium-GR. Phytotoxicity studies revealed no toxicity of the biodegraded products of Scarlet R by consortium-GR. In addition, consortium-GR applied for mixture of industrial dyes showed 88% decolorization under static condition with significant reduction in TOC (62%) and COD (68%) within 72 h, suggesting potential application of this microbial consortium in bioremediation of dye-containing wastewater.

  2. Generation and characterization of iUBC-KikGR photoconvertible transgenic mice for live time lapse imaging during development

    PubMed Central

    Griswold, Shannon L.; Sajja, Krishna C.; Jang, Chuan-Wei

    2012-01-01

    Summary A transgenic mouse line named iUBC-KikGR was generated which expresses the photoconvertible fluorescent protein Kikume Green-Red (KikGR) under the control of the human Ubiquitin C promoter. KikGR is natively a green fluorophore which can be converted into a red fluorophore upon exposure to UV light. KikGR is expressed broadly throughout transgenic embryos from the 2-cell stage onward, and in the adult. Specificity of photoconversion can range from the entire embryo, to a region of an organ, to a few individual cells, depending on the needs of the experimenter. Cell movements, tissue reorganization, and migration can then be observed in real time by culturing the tissue of interest as an explant on the microscope stage. The iUBC-KikGR transgenic line represents a singular genetic reagent which can be used for fate mapping, lineage tracing, and live visualization of cell behaviors and tissue movements in multiple organs at multiple time points. PMID:21309067

  3. Comparison of in vitro activity of GR 20263, a novel cephalosporin derivative, with activities of other beta-lactam compounds.

    PubMed Central

    Wise, R; Andrews, J M; Bedford, K A

    1980-01-01

    The in vitro activity of GR 20263, a new cephalosporin, was compared primarily with the activities of moxalactam (LY 127935), cefotaxime, cefoxitin, cefuroxime, and cefazolin against 293 clinical isolates of a variety of gram-positive and -negative bacteria. The minimal inhibitory concentrations of GR 20263 for 90% of group isolates were between 0.06 and 0.5 microgram/ml for the Enterobacteriaceae, Haemophilus influenzae, Neisseria gonorrhoeae, and Lancefield group A beta-hemolytic streptococci; 2 micrograms/ml for Pseudomonas aeruginosa; 16 micrograms/ml for Staphylococcus aureus; and in excess of 128 micrograms/ml for Bacteroides fragilis and Lancefield group D streptococci. In comparison with the other agents, GR 20263 was markedly more active against the Enterobacteriaceae than cefuroxime, cefoxitin, and cefazolin, but marginally less active than moxalactam or cofotaxime. Aganist S. aureus, cefazolin was 16-fold and cefotaxime was 4-fold more active than GR 20263 and moxalactam. GR 20263 was eight-fold more active than cefotaxime and moxalactam against P. aeruginosa. PMID:6772097

  4. Activation protein 1-dependent transcriptional activation of interleukin 2 gene by Ca2+/calmodulin kinase type IV/Gr

    PubMed Central

    1996-01-01

    The Ca2+/calmodulin-dependent protein kinase (CaMK) type IV/Gr is selectively expressed in T lymphocytes and is activated after signaling via the T cell antigen receptor (TCR), indicating that it mediates some of the Ca(2+)-dependent transcriptional events that follow TCR engagement. Here we show that CaMKIV/Gr induces the transcription factor activation protein 1 (AP-1) alone or in synergy with T cell mitogens and with the p21ras oncoprotein. CaMKIV/ Gr signaling is associated with transcriptional activation of c-fos but is independent of p21ras or calcineurin. AP-1 is an integral component of the nuclear factor of activated T cells (NFAT) transcriptional complex, which is required for interleukin 2 gene expression in T cells. We demonstrate that CaMKIV/Gr reconstitutes the capacity of the cytosolic component of NFAT to direct transcription from NFAT sites in non-T cells. These results reveal a central role for CaMKIV/Gr as a Ca(2+)-regulated activator of gene transcription in T lymphocytes. PMID:8691123

  5. IUGR increases chromatin-remodeling factor Brg1 expression and binding to GR exon 1.7 promoter in newborn male rat hippocampus.

    PubMed

    Ke, Xingrao; McKnight, Robert A; Gracey Maniar, Lia E; Sun, Ying; Callaway, Christopher W; Majnik, Amber; Lane, Robert H; Cohen, Susan S

    2015-07-15

    Intrauterine growth restriction (IUGR) increases the risk for neurodevelopment delay and neuroendocrine reprogramming in both humans and rats. Neuroendocrine reprogramming involves the glucocorticoid receptor (GR) gene that is epigenetically regulated in the hippocampus. Using a well-characterized rodent model, we have previously shown that IUGR increases GR exon 1.7 mRNA variant and total GR expressions in male rat pup hippocampus. Epigenetic regulation of GR transcription may involve chromatin remodeling of the GR gene. A key chromatin remodeler is Brahma-related gene-1(Brg1), a member of the ATP-dependent SWItch/Sucrose NonFermentable (SWI/SNF) chromatin remodeling complex. Brg1 regulates gene expression by affecting nucleosome repositioning and recruiting transcriptional components to target promoters. We hypothesized that IUGR would increase hippocampal Brg1 expression and binding to GR exon 1.7 promoter, as well as alter nucleosome positioning over GR promoters in newborn male pups. Further, we hypothesized that IUGR would lead to accumulation of specificity protein 1 (Sp1) and RNA pol II at GR exon 1.7 promoter. Indeed, we found that IUGR increased Brg1 expression and binding to GR exon 1.7 promoter. We also found that increased Brg1 binding to GR exon 1.7 promoter was associated with accumulation of Sp1 and RNA pol II carboxy terminal domain pSer-5 (a marker of active transcription). Furthermore, the transcription start site of GR exon 1.7 was located within a nucleosome-depleted region. We speculate that changes in hippocampal Brg1 expression mediate GR expression and subsequently trigger neuroendocrine reprogramming in male IUGR rats. PMID:25972460

  6. BCNU-induced gR2 defect mediates S-glutathionylation of Complex I and respiratory uncoupling in myocardium.

    PubMed

    Kang, Patrick T; Chen, Chwen-Lih; Ren, Pei; Guarini, Giacinta; Chen, Yeong-Renn

    2014-06-15

    A deficiency of mitochondrial glutathione reductase (or GR2) is capable of adversely affecting the reduction of GSSG and increasing mitochondrial oxidative stress. BCNU [1,3-bis (2-chloroethyl)-1-nitrosourea] is an anticancer agent and known inhibitor of cytosolic GR ex vivo and in vivo. Here we tested the hypothesis that a BCNU-induced GR2 defect contributes to mitochondrial dysfunction and subsequent impairment of heart function. Intraperitoneal administration of BCNU (40 mg/kg) specifically inhibited GR2 activity by 79.8 ± 2.7% in the mitochondria of rat heart. However, BCNU treatment modestly enhanced the activities of mitochondrial Complex I and other ETC components. The cardiac function of BCNU-treated rats was analyzed by echocardiography, revealing a systolic dysfunction associated with decreased ejection fraction, decreased cardiac output, and an increase in left ventricular internal dimension and left ventricular volume in systole. The respiratory control index of isolated mitochondria from the myocardium was moderately decreased after BCNU treatment, whereas NADH-linked uncoupling of oxygen consumption was significantly enhanced. Extracellular flux analysis to measure the fatty acid oxidation of myocytes indicated a 20% enhancement after BCNU treatment. When the mitochondria were immunoblotted with antibodies against GSH and UCP3, both protein S-glutathionylation of Complex I and expression of UCP3 were significantly up-regulated. Overexpression of SOD2 in the myocardium significantly reversed BCNU-induced GR2 inhibition and mitochondrial impairment. In conclusion, BCNU-mediated cardiotoxicity is characterized by the GR2 deficiency that negatively regulates heart function by impairing mitochondrial integrity, increasing oxidative stress with Complex I S-glutathionylation, and enhancing uncoupling of mitochondrial respiration.

  7. BCNU-INDUCED GR2 DEFECT MEDIATES S-GLUTATHIONYLATION OF COMPLEX I AND RESPIRATORY UNCOUPLING IN MYOCARDIUM†

    PubMed Central

    Kang, Patrick T.; Chen, Chwen-Lih; Zen, Pei; Guarini, Giacinta; Chen, Yeong-Renn

    2014-01-01

    A deficiency of mitochondrial glutathione reductase (or GR2) is capable of adversely affecting the reduction of GSSG and increasing mitochondrial oxidative stress. BCNU [1, 3-bis (2-chloroethyl)-1-nitrosourea] is an anticancer agent and known inhibitor of cytosolic GR ex vivo and in vivo. Here we tested the hypothesis that a BCNU-induced GR2 defect contributes to mitochondrial dysfunction and subsequent impairment of heart function. Intraperitoneal administration of BCNU (40 mg/kg) specifically inhibited GR2 activity by 79.8±2.7% in the mitochondria of rat heart. However, BCNU treatment modestly enhanced the activities of mitochondrial Complex I and other ETC components. The cardiac function of BCNU-treated rats was analyzed by echocardiography, revealing a systolic dysfunction associated with decreased ejection fraction, decreased cardiac output, and an increase in left ventricular internal dimension and left ventricular volume in systole. The respiratory control index of isolated mitochondria from the myocardium was moderately decreased after BCNU treatment, whereas NADH-linked uncoupling of oxygen consumption was significantly enhanced. Extracellular flux analysis to measure the fatty acid oxidation of myocytes indicated a 20% enhancement after BCNU treatment. When the mitochondria were immunoblotted with antibodies against GSH and UCP3, both protein S-glutathionylation of Complex I and expression of UCP3 were significantly up-regulated. Overexpression of SOD2 in the myocardium significantly reversed BCNU-induced GR2 inhibition and mitochondrial impairment. In conclusion, BCNU-mediated cardiotoxicity is characterized by the GR2 deficiency that negatively regulates heart function by impairing mitochondrial integrity, increasing oxidative stress with Complex I S-glutathionylation, and enhancing uncoupling of mitochondrial respiration. PMID:24704251

  8. Structure of the Grímsvötn central volcano under the Vatnajökull icecap, Iceland

    NASA Astrophysics Data System (ADS)

    Alfaro, Raimon; Brandsdóttir, Bryndís; Rowlands, Daniel P.; White, Robert S.; Gudmundsson, Magnús T.

    2007-02-01

    The subglacial Grímsvötn central volcano, lying within a volcanic zone directly above the core of the Iceland mantle plume, is one of the most active in Iceland. Local, regional and teleseismic earthquake data recorded on a temporary seismometer array across western Vatnajökull icecap during the summer of 1998 have provided a three-dimensional image of the shallow crustal structure of the volcano. Microearthquake activity at depths of 1-4 km along the Grímsvötn caldera rim coincided with inflation of a shallow magma chamber beneath the caldera, which culminated in a 0.1 km3 eruption in December 1998. Tomographic inversion of these earthquakes define the extent of a low-velocity body beneath Grímsvötn with a volume of ~20 km3 extending to ~3 km below the surface. This low-velocity body is flanked by high velocities under the caldera rim. Delays in the P-wave arrival times through the Grímsvötn caldera from regional and teleseismic earthquakes and from two detonations ~150 km east of Grímsvötn are 0.10-0.15 s greater than the delays through the uppermost 3-4 km of crust shown by local earthquake arrivals. This suggests the presence of a further low-velocity body at depths greater than 3-4 km beneath Grímsvötn, presumed to be due to the presence of melt. Using the distribution of local seismicity and shear wave attenuation we estimate the maximum lateral extent of the region containing partial melt to be 7-8 km E-W and 4-5 km N-S. P-wave delays require a thickness of less than 1 km of pure/high percentage partial melt, assuming a sill-like magma chamber.

  9. Bacillus amyloliquefaciens subsp. plantarum GR53, a potent biocontrol agent resists Rhizoctonia disease on Chinese cabbage through hormonal and antioxidants regulation.

    PubMed

    Kang, Sang-Mo; Radhakrishnan, Ramalingam; Lee, In-Jung

    2015-10-01

    The fungus Rhizoctonia solani is one of the causal agents of numerous diseases that affect crop growth and yield. The aim of this present investigation was to identify a biocontrol agent that acts against R. solani and to determine the agent's protective effect through phytohormones and antioxidant regulation in experimentally infected Chinese cabbage plants. Four rhizospheric soil bacterial isolates GR53, GR169, GR786, and GR320 were tested for their antagonistic activity against R. solani. Among these isolates, GR53 significantly suppressed fungal growth. GR53 was identified as Bacillus amyloliquefaciens subsp. plantarum by phylogenetic analysis of the 16S rDNA sequence. The biocontrol activity of B. amyloliquefaciens subsp. plantarum GR53 was tested in Chinese cabbage plants under controlled conditions. Results showed that R. solani inhibited plant growth (length, width, fresh and dry weight of leaves) by reducing chlorophyll and total phenolic content, as well as by increasing the levels of salicylic acid, jasmonic acid, abscisic acid, and DPPH scavenging activity. By regulating the levels of these compounds, the co-inoculation of B. amyloliquefaciens subsp. plantarum GR53 heightened induced systemic resistance in infected Chinese cabbage, effectively mitigating R. solani-induced damaging effects and improving plant growth. The results obtained from this study suggest that B. amyloliquefaciens subsp. plantarum GR53 is an effective biocontrol agent to prevent the damage caused by R. solani in Chinese cabbage plants.

  10. Reduced expression of 15-hydroxy prostaglandin dehydrogenase in chorion during labor is associated with decreased PRB and increased PRA and GR expression.

    PubMed

    Li, Yuan; He, Ping; Sun, Qianqian; Liu, Jie; Gao, Lu; You, Xingji; Gu, Hang; Ni, Xin

    2013-05-01

    The chorion laeve controls the levels of active prostaglandins within the uterus by NAD-dependent 15-hydroxy prostaglandin dehydrogenase (PGDH). The expression of PGDH in chorion is modulated by glucocorticoids and progesterone. In this study, we investigated glucocorticoid receptor (GR) and progesterone receptor A and B (PRA and PRB) in the regulation of PGDH expression in chorion, and we determined whether reduced PGDH expression in chorion during labor is associated with the changes in GR and PR expression by real-time RT-PCR and Western blot analysis. Dexamethasone (DEX) inhibited PGDH expression whereas progesterone stimulated PGDH expression in chorionic trophoblasts. DEX suppressed PGDH expression in GR overexpression and PR knockdown cells. The inhibitory effect of DEX did not occur in GR knockdown cells. Progesterone inhibited PGDH in GR overexpression and PR knockdown cells and it stimulated PGDH in PRB overexpression cells whereas it suppressed PGDH in PRA overexpression cells. Knockdown of c-Jun resulted in a loss of progesterone- and DEX-induced effects. PGDH was down-regulated in chorion tissues during labor. PRB was decreased whereas PRA and GR were increased in chorion during labor. Glucocorticoids inhibit PGDH expression via GR in chorionic trophoblasts. Progesterone enhances PGDH expression through PRB, whereas it inhibits PGDH expression via GR and PRA. Decreased PGDH expression is associated with increased GR and PRA, although decreased PRB, in chorion during labor.

  11. Expression of a sugar clade gustatory receptor, BmGr6, in the oral sensory organs, midgut, and central nervous system of larvae of the silkworm Bombyx mori.

    PubMed

    Mang, Dingze; Shu, Min; Endo, Haruka; Yoshizawa, Yasutaka; Nagata, Shinji; Kikuta, Shingo; Sato, Ryoichi

    2016-03-01

    Insects taste nonvolatile chemicals through gustatory receptors (Grs) and make choices for feeding, mating, and oviposition. To date, genome projects have identified 69 Gr genes in the silkworm, Bombyx mori; however, the expression sites of these Grs remain to be explored. In this study, we used reverse transcription (RT)-PCR to investigate expression of the B. mori Gr-6 (BmGr6) gene, a member of the putative sugar clade gene family in various tissues. BmGr6 is expressed in the midgut, central nervous system (CNS), and oral sensory organs. Moreover, immunohistochemistry using an anti-BmGr6 antiserum demonstrated that BmGr6 is expressed in cells by oral sensory organs, midgut and nervous system. Furthermore, double-immunohistochemistry indicated that BmGr6 is expressed in midgut enteroendocrine cells, also in CNS neurosecretory cells. In particular, a portion of BmGr6-expressing cells, in both midgut and CNS, secretes FMRFamide-related peptides (FaRPs). These results suggest that BmGr6 functions not only as a taste receptor, but also as a chemical sensor such as for the regulation of gut movement, physiological conditions, and feeding behavior of larvae. PMID:26721200

  12. Bacillus amyloliquefaciens subsp. plantarum GR53, a potent biocontrol agent resists Rhizoctonia disease on Chinese cabbage through hormonal and antioxidants regulation.

    PubMed

    Kang, Sang-Mo; Radhakrishnan, Ramalingam; Lee, In-Jung

    2015-10-01

    The fungus Rhizoctonia solani is one of the causal agents of numerous diseases that affect crop growth and yield. The aim of this present investigation was to identify a biocontrol agent that acts against R. solani and to determine the agent's protective effect through phytohormones and antioxidant regulation in experimentally infected Chinese cabbage plants. Four rhizospheric soil bacterial isolates GR53, GR169, GR786, and GR320 were tested for their antagonistic activity against R. solani. Among these isolates, GR53 significantly suppressed fungal growth. GR53 was identified as Bacillus amyloliquefaciens subsp. plantarum by phylogenetic analysis of the 16S rDNA sequence. The biocontrol activity of B. amyloliquefaciens subsp. plantarum GR53 was tested in Chinese cabbage plants under controlled conditions. Results showed that R. solani inhibited plant growth (length, width, fresh and dry weight of leaves) by reducing chlorophyll and total phenolic content, as well as by increasing the levels of salicylic acid, jasmonic acid, abscisic acid, and DPPH scavenging activity. By regulating the levels of these compounds, the co-inoculation of B. amyloliquefaciens subsp. plantarum GR53 heightened induced systemic resistance in infected Chinese cabbage, effectively mitigating R. solani-induced damaging effects and improving plant growth. The results obtained from this study suggest that B. amyloliquefaciens subsp. plantarum GR53 is an effective biocontrol agent to prevent the damage caused by R. solani in Chinese cabbage plants. PMID:26160009

  13. Islet adaptation to obesity and insulin resistance in WNIN/GR-Ob rats

    PubMed Central

    Singh, Himadri; Ganneru, Sireesha; Malakapalli, Venkata; Chalasani, Maniprabha; Nappanveettil, Giridharan; Bhonde, Ramesh R; Venkatesan, Vijayalakshmi

    2014-01-01

    WNIN/GR-Ob mutant rat is a novel animal model to study metabolic syndrome (obesity, insulin resistance, hyperinsulinemia, impaired glucose tolerance and cardiovascular diseases). We have investigated the islet characteristics of obese mutants at different age groups (1, 6 and 12 months) to assess the islet changes in response to early and chronic metabolic stress. Our data demonstrates altered islet cell morphology and function (hypertrophy, fibrotic lesions, vacuolation, decreased stimulation index, increased TNFα, ROS and TBARS levels) in mutants as compared to controls. Furthermore, network analysis (gene-gene interaction) studied in pancreas demonstrated increased inflammation as a key factor underlying obesity/metabolic syndrome in mutants. These observations pave way to explore this model to understand islet adaptation in response to metabolic syndrome. PMID:25833252

  14. Thermal equation of state and thermodynamic Grüneisen parameter of beryllium metal

    SciTech Connect

    Zhang, Jianzhong Zhu, Jinlong; Velisavljevic, Nenad; Wang, Liping; Zhao, Yusheng

    2013-11-07

    We conducted in-situ high-pressure synchrotron x-ray experiments on beryllium metal at pressures up to 7.9 GPa and temperatures up to 1373 K. A complete pressure (P)–volume (V)–temperature (T) equation of state (EOS) is determined based on the experiment, which includes temperature derivatives of elastic bulk modulus (at both constant pressure and constant volume) and pressure dependence of thermal expansivity. From this EOS, we calculate thermal pressure, heat capacity at constant volume, and thermodynamic Grüneisen parameter as a function of temperature. Above ∼600 K, our results show notable deviation from theoretical predictions using the quasiharmonic and local-density approximations, indicating that the free energy calculations need to be further improved within the current scheme of approximations.

  15. Islet adaptation to obesity and insulin resistance in WNIN/GR-Ob rats.

    PubMed

    Singh, Himadri; Ganneru, Sireesha; Malakapalli, Venkata; Chalasani, Maniprabha; Nappanveettil, Giridharan; Bhonde, Ramesh R; Venkatesan, Vijayalakshmi

    2014-01-01

    WNIN/GR-Ob mutant rat is a novel animal model to study metabolic syndrome (obesity, insulin resistance, hyperinsulinemia, impaired glucose tolerance and cardiovascular diseases). We have investigated the islet characteristics of obese mutants at different age groups (1, 6 and 12 months) to assess the islet changes in response to early and chronic metabolic stress. Our data demonstrates altered islet cell morphology and function (hypertrophy, fibrotic lesions, vacuolation, decreased stimulation index, increased TNFα, ROS and TBARS levels) in mutants as compared to controls. Furthermore, network analysis (gene-gene interaction) studied in pancreas demonstrated increased inflammation as a key factor underlying obesity/metabolic syndrome in mutants. These observations pave way to explore this model to understand islet adaptation in response to metabolic syndrome.

  16. Modelling of activation processes for GR-280 graphite at Ignalina NPP.

    PubMed

    Smaizys, Arturas; Narkunas, Ernestas; Poskas, Povilas

    2005-01-01

    Ignalina Nuclear Power Plant (INPP) operates two RBMK-1500 water-cooled graphite-moderated channel-type power reactors. The total mass of graphite in the cores of both units at INPP is about 3600 tons. Modelling of activation processes in the reactor's structural materials is necessary for decommissioning planning, because large amounts of activated structural materials (graphite, stainless steel, concrete, etc.) should be managed as radioactive waste. Knowledge of radiological characteristics and a radioactive inventory of irradiated materials are essential in planning of the decommissioning processes. The purpose of this work was to perform conservative neutron activation analysis for decommissioning purposes of INPP. ORIGEN computer code was used for the calculations. Activity levels were calculated for different nuclides present in the graphite and estimates were made how these activity levels depend on irradiation time, neutron flux value and other parameters. Obtained results were compared with the data available from other investigations for GR-280 graphite.

  17. Modelling of activation processes for GR-280 graphite at Ignalina NPP.

    PubMed

    Smaizys, Arturas; Narkunas, Ernestas; Poskas, Povilas

    2005-01-01

    Ignalina Nuclear Power Plant (INPP) operates two RBMK-1500 water-cooled graphite-moderated channel-type power reactors. The total mass of graphite in the cores of both units at INPP is about 3600 tons. Modelling of activation processes in the reactor's structural materials is necessary for decommissioning planning, because large amounts of activated structural materials (graphite, stainless steel, concrete, etc.) should be managed as radioactive waste. Knowledge of radiological characteristics and a radioactive inventory of irradiated materials are essential in planning of the decommissioning processes. The purpose of this work was to perform conservative neutron activation analysis for decommissioning purposes of INPP. ORIGEN computer code was used for the calculations. Activity levels were calculated for different nuclides present in the graphite and estimates were made how these activity levels depend on irradiation time, neutron flux value and other parameters. Obtained results were compared with the data available from other investigations for GR-280 graphite. PMID:16604642

  18. Geodetic constraints on volcanic plume height at Grímsvötn volcano, Iceland

    NASA Astrophysics Data System (ADS)

    Hreinsdóttir, Sigrún; Sigmundsson, Freysteinn; Roberts, Matthew; Björnsson, Halldór; Grapenthin, Ronni; Arason, Pórdur; Árnadóttir, Thóra; Hólmjárn, Jósef; Geirsson, Halldór; Bennett, Richard; Gudmundsson, Magnús; Oddsson, Björn; Ófeigsson, Benedikt; Villemin, Thierry; Jónsson, Torsteinn; Sturkell, Erik; Höskuldsson, Ármann; Larsen, Gudrún; Thordarson, Thor; Óladóttir, Bergrún

    2014-05-01

    In 2011 a VEI 4 explosive eruption took place at Grímsvötn volcano, Iceland. Grímsvötn is a subglacial basaltic volcano beneath the Vatnajökull ice cap. It is Iceland's most frequently erupting volcano, with recent eruptions in 1983, 1998, 2004, and 2011. The volcano has a low seismic velocity anomaly down to about 3 km depth, interpreted as a magma chamber. A continuous GPS station and a tiltmeter are located on a nunatak, Mount Grímsfjall, which protrudes from the ice at the southern rim of the caldera. The 21-28 May 2011 eruption was Grímsvötn's largest since 1873, resulting in airspace closure in northern Europe and the cancellation of about 900 passenger flights. The eruption was preceded by gradual inflation following the 2004 eruption and progressive increase in seismicity. Kinematic 1 Hz solutions were derived for the position of the GPS station in the hours immediately before and during the 2011 eruption. The onset of deformation preceded the eruption by one hour and reached maximum of 0.57 m within 48 hours. Throughout the eruption the GPS station moved consistently in direction N38.4+/-0.5W, opposite to the direction of movements during the 2004-2011 inter eruptive phase. The deformation characteristics suggest that the signal was mostly due to pressure change in a source at 1.7 +/- 0.2 km depth. We use the geodetic measurements to infer co-eruptive pressure change in the magma chamber using the Mogi model. The rate of pressure drop is then used to estimate the magma flow rate from the chamber. Numerous studies have shown that plume height in explosive eruptions can be related to magma discharge. Using an empirical relationship between the volcanic plume height and magma flow rate (Mastin et al., 2009) we estimate the evolution of the plume height from the geodetic data. Two weather radars monitored the height of the volcanic plume during the eruption. A strong initial plume with peaks at 20-25 km was followed by a declining, pulsating activity

  19. Goneis.gr: Training Greek Parents on ICT and Safer Internet

    NASA Astrophysics Data System (ADS)

    Manouselis, Nikos; Riviou, Katerina; Palavitsinis, Nikos; Giannikopoulou, Vasiliki; Tsanakas, Panayotis

    Children's use of the Internet has significantly risen in the last decade. Nevertheless, children spend a lot of time online which makes them susceptible to various threats (such as inappropriate material, offensive language, etc). Parents are the last frontier to this menace but they also need to be educated and trained in order to protect their children. Goneis.gr is an initiative launched by the Greek government that aims to educate parents on safer Internet and the use of parental control software. Parents are also entitled to distance learning courses covering basic computer skills. This paper presents the results of two separate surveys that took place in the last few months (December 2008-January 2009). The first survey targeted the parents that have completed the programme and the second one the educational providers that participate in the programme and offer the training to the beneficiaries.

  20. The May 2011 eruption of Grímsvötn

    NASA Astrophysics Data System (ADS)

    Gudmundsson, M. T.; Höskuldsson, Á.; Larsen, G.; Thordarson, T.; Oladottir, B. A.; Oddsson, B.; Gudnason, J.; Högnadottir, T.; Stevenson, J. A.; Houghton, B. F.; McGarvie, D.; Sigurdardottir, G. M.

    2012-04-01

    Grímsvötn is the most active volcano in Iceland with >60 known eruptions in the last 800 years. Grímsvötn is located in the centre of the 8100 km2 Vatnajökull glacier and typically produces basalts in phreatomagmatic eruptions. Magma-water interaction occurs as the eruptions quickly melt their way through 50-200 m thick ice covering a subglacial caldera lake. Most of these eruptions have been relatively modest in size (0.01-0.1 km3 DRE) causing relatively minor fallout of tephra outside Vatnajökull. After a relative quiet second half of the 20th century, a period of increased volcanic activity in Grímsvötn started in the 1990s, with basaltic phreatomagmatic eruptions occurring within the caldera in 1998 and 2004. The 2011 eruption was therefore expected. It began at 19 UTC on 21 May. The plume quickly rose to 15-20 km, forming a 50-100 km wide umbrella cloud that was maintained until late on 22 May. Heavy fallout occurred in the districts 70-100 km south of the volcano, where periods of total darkness with drifting ash closed roads and caused distress to the local population. Wind directions and plume transport varied somewhat during the eruption. After 23 May, the eruption was relatively minor, with fallout mostly confined to the Vatnajökull glacier. The eruption ended on May 28. Most of the magma was erupted in the first two days. During this period strong northerly winds were dominant at low altitude, carrying the tephra towards south as a 2-4 km high cloud, while the top part of the plume first drifted eastwards and later northwards. Most of the fallout after the first few hours came from the low southwards drifting cloud while the high plume was white in colour and with apparently low concentration of ash leading to only minor fallout. This eruption falls into a class of events that seem to happen once every 100-200 years, with previous large historical eruptions including 1619 and 1873. Preliminary estimates indicate that the eruption produced 0

  1. Temperature and pressure dependence of the mode Grüneisen parameters close to the melting point in hexagonal ice

    NASA Astrophysics Data System (ADS)

    Karacali, H.; Yurtseven, H.

    2007-02-01

    We reexamine the Pippard relations in this study by relating the specific heat CP to the Raman frequency shifts 1/ν∂ and the thermal expansivity αp to the 1/ν∂, when the mode Grüneisen parameter depends on the temperature and pressure close to the melting point in hexagonal ice. From linear relations between them, the values of the slope {dP}/{dT} are deduced in this crystal. Our slope values calculated here do not change significantly compared to those obtained when the mode Grüneisen parameter is taken as a constant close to the melting point in hexagonal ice.

  2. [Healing current through a goiter. The life, work and after effects of the magic healer Bruno Gröning].

    PubMed

    Mildenberger, Florian

    2008-01-01

    During the years between 1949 and 1959 the wonder healer Bruno Gröning (1906-1959) gripped the public and medical interest in Germany. He explained to be a descent of Jesus Christ, sending "healing waves" to end diseases and made a lot of money. Finally he was found guilty in letting a persuaded fan dying and was convicted. But before the end of the process he died of carcinoma, which had been operated in a regular clinic. Despite this obvious problem that Gröning demanded from his admirers refusing medical help but preferred it for his own health today his successors are still promoting his legacy.

  3. Electron attachment and detachment, and the electron affinities of C5F5N and C5HF4N.

    PubMed

    Van Doren, Jane M; Kerr, Donna M; Miller, Thomas M; Viggiano, A A

    2005-09-15

    Rate constants have been measured for electron attachment to C5F5N (297-433 K) and to 2, 3, 5, 6-C5HF4N (303 K) using a flowing-afterglow Langmuir-probe apparatus (at a He gas pressure of 133 Pa). In both cases only the parent anion was formed in the attachment process. The attachment rate constants measured at room temperature are 1.8 +/- 0.5 X 10(-7) and 7 +/- 3 X 10(-10) cm(-3) s(-1), respectively. Rate constants were also measured for thermal electron detachment from the parent anions of these molecules. For C5F5N- detachment is negligible at room temperature, but increases to 2530 +/- 890 s(-1) at 433 K. For 2, 3, 5, 6-C5HF4N-, the detachment rate at 303 K was 520 +/- 180 s(-1). The attachment/detachment equilibrium yielded experimental electron affinities EA(C5F5N)=0.70 +/- 0.05 eV and EA(2, 3, 5, 6-C5HF4N)=0.40 +/- 0.08 eV. Electronic structure calculations were carried out for these molecules and related C5HxF5-xN using density-functional theory and the G3(MP2)//B3LYP compound method. The EAs are found to decrease by 0.25 eV, on average, with each F substitution by H. The calculated EAs are in good agreement with the present experimental results.

  4. Gravitational energy for GR and Poincaré gauge theories: A covariant Hamiltonian approach

    NASA Astrophysics Data System (ADS)

    Chen, Chiang-Mei; Nester, James M.; Tung, Roh-Suan

    2015-08-01

    Our topic concerns a long standing puzzle: The energy of gravitating systems. More precisely we want to consider, for gravitating systems, how to best describe energy-momentum and angular momentum/center-of-mass momentum (CoMM). It is known that these quantities cannot be given by a local density. The modern understanding is that (i) they are quasi-local (associated with a closed 2-surface), (ii) they have no unique formula, (iii) they have no reference frame independent description. In the first part of this work, we review some early history, much of it not so well known, on the subject of gravitational energy in Einstein's general relativity (GR), noting especially Noether's contribution. In the second part, we review (including some new results) much of our covariant Hamiltonian formalism and apply it to Poincaré gauge theories of gravity (PG), with GR as a special case. The key point is that the Hamiltonian boundary term has two roles, it determines the quasi-local quantities, and furthermore, it determines the boundary conditions for the dynamical variables. Energy-momentum and angular momentum/CoMM are associated with the geometric symmetries under Poincaré transformations. They are best described in a local Poincaré gauge theory. The type of spacetime that naturally has this symmetry is Riemann-Cartan spacetime, with a metric compatible connection having, in general, both curvature and torsion. Thus our expression for the energy-momentum of physical systems is obtained via our covariant Hamiltonian formulation applied to the PG.

  5. Variations in geothermal heat flux at Grímsvötn, Iceland

    NASA Astrophysics Data System (ADS)

    Iona Reynolds, Hannah; Tumi Gudmundsson, Magnús

    2014-05-01

    Thermal signals from sub-surface magmatic sources are difficult to quantify, as the measurement of fluxes from the ground to the atmosphere is subject to large uncertainties. Ice cauldrons are depressions which form on the surface of glaciers due to basal melting as a result of geothermal flux from the bedrock beneath, often generated by volcanic sources. The monitoring of ice cauldrons provides a unique opportunity to quantify heat flux to a much improved accuracy, as the melting ice acts as a calorimeter. Time series data of ice surface elevation at cauldrons above Grímsvötn volcano are presented over a 14 year period, with estimates of the melt volume and surface heat flux required for this melting to have occurred. Three volcanic eruptions took place at Grímsvötn during the study period, the effects of which are visible in ice surface elevation data. However, separate thermal anomalies are observed in areas unaffected by erupted products. A peak in surface heat flux is observed following the 1998 eruption, several kilometres east of the vent, with a maximum rise of ~200 W·m-2. The anomalous signal lasts for approximately three years. Possible explanations include the intrusion of a dyke beneath this area during the eruption, or increased permeability from greater dilatational strain due to regional stress, both of which would significantly increase heat flux. We investigate possible scenarios which could produce such a thermal anomaly, using finite element modelling. The effects of cooling magmatic intrusions and changes to the parameter space for country rock conductivity and permeability are considered, in relation to heat flux and the timescales and spatial extent of associated surface anomalies. Our results advance the understanding and interpretation of thermal signals observed at ice-covered volcanoes.

  6. Electronic structure and pair potential energy analysis of 4-n-methoxy-4'-cyanobiphenyl: A nematic liquid crystal

    NASA Astrophysics Data System (ADS)

    Sharma, Dipendra; Dwivedi, M. K.; Tiwari, S. N.

    2016-05-01

    Electronic structure properties of 4-n-methoxy-4'-cyanobiphenyl, a pure nematic liquid crystal have been examined using an ab‒initio, HF/6‒31G(d,p) technique with GAMESS program. Conformational and charge distribution analysis have been carried out. MEP, HOMO and LUMO surfaces have been scanned. Ionization potential, electron affinity, electronegativity, global hardness and softness of the liquid crystal molecule have been calculated. Further, stacking, side by side and end to end interactions between a molecular pair have been evaluated. Results have been used to elucidate the physico-chemical and liquid crystalline properties of the system.

  7. Molecular characterization of an influenza A virus (H4N2) isolated from waterfowl habitats in the State of Mexico.

    PubMed

    Ornelas-Eusebio, Erika; Obregón-Ascencio, Alejandro; Chávez-Maya, Fernando; García-Espinosa, Gary

    2015-03-01

    Wild waterfowl and their habitats are the main reservoirs of influenza A virus (IAV) mainly during the breeding season and prior to migration. This study describes the molecular characterization of an IAV isolated from 240 water samples of a small wetland during non-breeding season of migratory wild ducks in the State of Mexico, Mexico. The results showed that the virus belongs to the H4N2 subtype and each of its eight segments of the viral genome has similarity to IAV isolated from ducks in North America. This study suggests that IAV can be isolated from small wetland during non-breeding season of migrating waterfowl. PMID:25482497

  8. Molecular characterization of an influenza A virus (H4N2) isolated from waterfowl habitats in the State of Mexico.

    PubMed

    Ornelas-Eusebio, Erika; Obregón-Ascencio, Alejandro; Chávez-Maya, Fernando; García-Espinosa, Gary

    2015-03-01

    Wild waterfowl and their habitats are the main reservoirs of influenza A virus (IAV) mainly during the breeding season and prior to migration. This study describes the molecular characterization of an IAV isolated from 240 water samples of a small wetland during non-breeding season of migratory wild ducks in the State of Mexico, Mexico. The results showed that the virus belongs to the H4N2 subtype and each of its eight segments of the viral genome has similarity to IAV isolated from ducks in North America. This study suggests that IAV can be isolated from small wetland during non-breeding season of migrating waterfowl.

  9. Molecular characterization of an influenza A virus (H4N2) isolated from waterfowl habitats in the State of Mexico

    PubMed Central

    ORNELAS-EUSEBIO, Erika; OBREGÓN-ASCENCIO, Alejandro; CHÁVEZ-MAYA, Fernando; GARCÍA-ESPINOSA, Gary

    2014-01-01

    Wild waterfowl and their habitats are the main reservoirs of influenza A virus (IAV) mainly during the breeding season and prior to migration. This study describes the molecular characterization of an IAV isolated from 240 water samples of a small wetland during non-breeding season of migratory wild ducks in the State of Mexico, Mexico. The results showed that the virus belongs to the H4N2 subtype and each of its eight segments of the viral genome has similarity to IAV isolated from ducks in North America. This study suggests that IAV can be isolated from small wetland during non-breeding season of migrating waterfowl. PMID:25482497

  10. catena-Poly[[aqua-{4-[N'-(2,4-dioxo-3-pentyl-idene)-hydrazino]-benzoato}-copper(II)]-μ-acetato].

    PubMed

    Hao, Lujiang; Mu, Chunhua; Wang, Ridong

    2008-01-01

    In the title compound, [Cu(CH(3)CO(2))(C(12)H(11)N(2)O(4))(H(2)O)](n), the Cu(II) cation is tetra-coordinated by three carboxyl-ate O atoms from one 4-[N'-(2,4-dioxo-3-pentyl-idene)-hydrazino]-benzoate ligand and two acetate bridges, and by one water mol-ecule. The acetate bridges link adjacent Cu(II) cations, forming a chain. The crystal structure involves O-H⋯O hydrogen bonds. PMID:21202784

  11. The mitigating effect of calcification-dependent of utilization of inorganic carbon of Chara vulgaris Linn on NH4-N toxicity.

    PubMed

    Wang, Heyun; Ni, Leyi; Xie, Ping

    2013-09-01

    Increased ammonium (NH4-N) concentrations in water bodies have been reported to adversely affect the dominant species of submersed vegetation in meso-eutrophic waters worldwide. However calcareous plants were lowly sensitive to NH4-N toxicity. In order to make clear the function of calcification in the tolerance of calcareous plants to NH4-N stress, we studied the effects of increased HCO3(-) and additional NH4-N on calcification and utilization of dissolve inorganic carbon (DIC) in Chara vulgaris Linn in a 7-d sub-acute experiment (light:dark 12:12h) carried out in an open experimental system in lab. Results revealed that calcification was dependent of utilization of dissolve inorganic carbon. Additional HCO3(-) significantly decreased the increase of pH while additional NH4-N did not. And additional HCO3(-) significantly improved calcification while NH4-N did in versus in relation to the variation of DIC concentration. However, addition of both HCO3(-) and NH4-N increased utilization of DIC. This resulted in calcification to utilization of DIC ratio decreased under additional NH4-N condition while increased under additional HCO3(-) conditions in response to the variation of solution pH. In the present study, external HCO3(-) decreased the increase of solution pH by increasing calcification, which correspondingly mitigated the toxic effect of high NH4-N. And we argue that the mitigating effect of increased HCO3(-) on NH4-N toxicity is dependent of plant calcification, and it is a positive feedback mechanism, potentially leading to the dominance of calcareous plants in meso-eutrophic water bodies.

  12. The mitigating effect of calcification-dependent of utilization of inorganic carbon of Chara vulgaris Linn on NH4-N toxicity.

    PubMed

    Wang, Heyun; Ni, Leyi; Xie, Ping

    2013-09-01

    Increased ammonium (NH4-N) concentrations in water bodies have been reported to adversely affect the dominant species of submersed vegetation in meso-eutrophic waters worldwide. However calcareous plants were lowly sensitive to NH4-N toxicity. In order to make clear the function of calcification in the tolerance of calcareous plants to NH4-N stress, we studied the effects of increased HCO3(-) and additional NH4-N on calcification and utilization of dissolve inorganic carbon (DIC) in Chara vulgaris Linn in a 7-d sub-acute experiment (light:dark 12:12h) carried out in an open experimental system in lab. Results revealed that calcification was dependent of utilization of dissolve inorganic carbon. Additional HCO3(-) significantly decreased the increase of pH while additional NH4-N did not. And additional HCO3(-) significantly improved calcification while NH4-N did in versus in relation to the variation of DIC concentration. However, addition of both HCO3(-) and NH4-N increased utilization of DIC. This resulted in calcification to utilization of DIC ratio decreased under additional NH4-N condition while increased under additional HCO3(-) conditions in response to the variation of solution pH. In the present study, external HCO3(-) decreased the increase of solution pH by increasing calcification, which correspondingly mitigated the toxic effect of high NH4-N. And we argue that the mitigating effect of increased HCO3(-) on NH4-N toxicity is dependent of plant calcification, and it is a positive feedback mechanism, potentially leading to the dominance of calcareous plants in meso-eutrophic water bodies. PMID:23755986

  13. Determining a Structural Distortion and Anion Ordering in La2Si4N6C via Computation and Experiment.

    PubMed

    Hermus, Martin; Mansouri Tehrani, Aria; Brgoch, Jakoah

    2016-09-19

    A structural instability in the orthorhombic carbonitridosilicate La2Si4N6C arises when calculating the ab initio phonon dispersion curves. The presence of imaginary modes indicates the compound reported in space group Pnma is dynamically unstable with the eigenvectors showing a monoclinic distortion pathway leading to space group P21/c. Synthesizing La2Si4N6C using a high-temperature route and conducting a co-refinement with high-resolution synchrotron X-ray and neutron powder diffraction shows the predicted peak splitting confirming the predicted lower symmetry crystal structure. Further, the combination of ab initio computation, neutron diffraction, and a total scattering analysis based on a neutron pair distribution function analysis supports that the anions are fully ordered and that carbon is only found on the central position of a star-shaped C(SiN3)4 unit. These results illustrate the power of combining computation and experiment to unequivocally solve crystal structures from polycrystalline powders.

  14. Determination of 2-ethylhexyl 4-(N-methyl-N-nitrosamino) benzoate in commercial sunscreens and cosmetic products.

    PubMed

    Chou, H J; Yates, R L; Havery, D C; Wenninger, J A

    1995-01-01

    An analytical method has been developed for determination of 2-ethylhexyl 4-(N-methyl-N-nitrosamino) benzoate (NMPABAO), a nitrosamine contaminant in sunscreen products containing 2-ethylhexyl 4-(N,N-dimethylamino) benzoate (Padimate O). The method involves extraction of NMPABAO by column chromatography followed by liquid chromatographic separation and analysis wit a nitric oxide detector. To confirm the presence of NMPABAO in sunscreen products, the N-nitrosamine was synthesized and its structure was determined by infrared spectrophotometry, nuclear magnetic resonance spectrometry, and mass spectrometry (MS). For method validation, recovery studies were performed on a commercial suntan lotion, cream, and gel. Recoveries of NMPABAO added to representative test samples averaged 83%. The method has an estimated detection limit of 30 ppb. The method was used to analyze 25 commercial cosmetic and sunscreen products containing Padimate O. Eleven products contained NMPABAO at levels ranging from 160 to 21000 ppb. NMPABAO presence in 4 products was confirmed by MS at levels > or = 4000 ppb. The highest levels of NMPABAO were associated with products that contained the nitrite-releasing preservative 2-bromo-2-nitro-1,3-propanediol.

  15. DNA replication checkpoint signaling depends on a Rad53-Dbf4 N-terminal interaction in Saccharomyces cerevisiae.

    PubMed

    Chen, Ying-Chou; Kenworthy, Jessica; Gabrielse, Carrie; Hänni, Christine; Zegerman, Philip; Weinreich, Michael

    2013-06-01

    Dbf4-dependent kinase (DDK) and cyclin-dependent kinase (CDK) are essential to initiate DNA replication at individual origins. During replication stress, the S-phase checkpoint inhibits the DDK- and CDK-dependent activation of late replication origins. Rad53 kinase is a central effector of the replication checkpoint and both binds to and phosphorylates Dbf4 to prevent late-origin firing. The molecular basis for the Rad53-Dbf4 physical interaction is not clear but occurs through the Dbf4 N terminus. Here we found that both Rad53 FHA1 and FHA2 domains, which specifically recognize phospho-threonine (pT), interacted with Dbf4 through an N-terminal sequence and an adjacent BRCT domain. Purified Rad53 FHA1 domain (but not FHA2) bound to a pT Dbf4 peptide in vitro, suggesting a possible phospho-threonine-dependent interaction between FHA1 and Dbf4. The Dbf4-Rad53 interaction is governed by multiple contacts that are separable from the Cdc5- and Msa1-binding sites in the Dbf4 N terminus. Importantly, abrogation of the Rad53-Dbf4 physical interaction blocked Dbf4 phosphorylation and allowed late-origin firing during replication checkpoint activation. This indicated that Rad53 must stably bind to Dbf4 to regulate its activity.

  16. Decrease of NH4+-N by bacterioplankton accelerated the removal of cyanobacterial blooms in aerated aquatic ecosystem.

    PubMed

    Yang, Xi; Xie, Ping; Ma, Zhimei; Wang, Qing; Fan, Huihui; Shen, Hong

    2013-11-01

    We used aerated systems to assess the influence of the bacterioplankton community on cyanobacterial blooms in algae/post-bloom of Lake Taihu, China. Bacterioplankton community diversity was evaluated by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprinting. Chemical analysis and nitrogen dynamic changes illustrated that NH4+-N was nitrified to NO2--N and NO3--N by bacterioplankton. Finally, NH4+-N was exhausted and NO3--N was denitrified to NO2--N, while the accumulation of NO2--N indicated that bacterioplankton with completely aerobic denitrification ability were lacking in the water samples collected from Lake Taihu. We suggested that adding completely aerobic denitrification bacteria (to denitrify NO2--N to N2) would improve the water quality. PCR-DGGE and sequencing results showed that more than1/3 of the bacterial species were associated with the removal of nitrogen, and Acidovorax temperans was the dominant one. PCR-DGGE, variation of nitrogen, removal efficiencies of chlorophyll-a and canonical correspondence analysis indicated that the bacterioplanktonsignificantly influenced the physiological and biochemical changes of cyanobacteria. Additionally, the unweighted pair-group method with arithmetic means revealed there was no obvious harm to the microecosystem from aeration. The present study demonstrated that bacterioplankton can play crucial roles in aerated ecosystems, which could control the impact of cyanobacterial blooms in eutrophicated fresh water systems.

  17. Determining a Structural Distortion and Anion Ordering in La2Si4N6C via Computation and Experiment.

    PubMed

    Hermus, Martin; Mansouri Tehrani, Aria; Brgoch, Jakoah

    2016-09-19

    A structural instability in the orthorhombic carbonitridosilicate La2Si4N6C arises when calculating the ab initio phonon dispersion curves. The presence of imaginary modes indicates the compound reported in space group Pnma is dynamically unstable with the eigenvectors showing a monoclinic distortion pathway leading to space group P21/c. Synthesizing La2Si4N6C using a high-temperature route and conducting a co-refinement with high-resolution synchrotron X-ray and neutron powder diffraction shows the predicted peak splitting confirming the predicted lower symmetry crystal structure. Further, the combination of ab initio computation, neutron diffraction, and a total scattering analysis based on a neutron pair distribution function analysis supports that the anions are fully ordered and that carbon is only found on the central position of a star-shaped C(SiN3)4 unit. These results illustrate the power of combining computation and experiment to unequivocally solve crystal structures from polycrystalline powders. PMID:27598316

  18. Transparent half metallic g-C4N3 nanotubes: potential multifunctional applications for spintronics and optical devices.

    PubMed

    Hu, Tao; Hashmi, Arqum; Hong, Jisang

    2014-08-14

    Multifunctional material brings many interesting issues because of various potential device applications. Using first principles calculations, we predict that the graphitic carbon nitride (g-C4N3) nanotubes can display multifunctional properties for both spintronics and optical device applications. Very interestingly, armchair tubes (n, n) with n = 2, 3, 4, 5, 6 and (5, 0) zigzag tubes are found to be half metallic, while zigzag tubes (n, 0) with n = 4, 6 show an antiferromagnetic ground state with band gaps. However, larger zigzag tubes of (7, 0), (8, 0), and (10, 0) are turned out to be half metallic. Along with the half metallic behavior of the tubes, those tubes seem to be optically transparent in the visible range. Due to these magnetic and optical properties, we suggest that the g-C4N3 nanotubes (CNNTs) can be used for both ideal spintronics and transparent electrode materials. We also explored the stability of magnetic state and nanotube structure using ab initio molecular dynamics. The CNNTs were found to be thermally stable and the magnetic moment was robust against the structural deformation at 300 K. Overall, our theoretical prediction in one dimensional CNNTs may provide a new physics in spintronics and also in other device applications because of potential multifunctional properties.

  19. Bottom-up substitution assembly of AuF4-n0,-+nPO3 (n = 1-4): a theoretical study of novel oxyfluoride hyperhalogen molecules and anions AuF4-n(PO3)n0,-

    NASA Astrophysics Data System (ADS)

    Yang, Yi-fan; Cui, Zhong-hua; Ding, Yi-hong

    2014-06-01

    Compounds with high electron affinity, i.e. superhalogens, have continued to attract chemists' attention, due to their potential importance in fundamental chemistry and materials science. It has now proven very effective to build up novel superhalogens with multi-positively charged centres, which are usually called 'hyperhalogens'. Herein, using AuF4- and PO3 as the model building blocks, we made the first attempt to design the Au,P-based hyperhalogen anions AuF4-n(PO3)n- (n = 1-4) at the B3LYP/6-311+G(d)&SDD and CCSD(T)/6-311+G(d)&SDD (single-point) levels (6-311+G(d) for O, F, P and SDD for Au). Notably, for all the considered Au,P systems, the ground state bears a dioxo-bonded structure with n ≤ 3, which is significantly more stable than the usually presumed mono-oxo-bonded one. Moreover, the clustering of the -PO3 moieties becomes energetically favoured for n ≥ 3. The ground states of AuP4O120,- are the first reported cage-like oxide hyperhalogens. Thus, the -PO3 moiety cannot be retained during the 'bottom-up' assembly. The vertical detachment energy (VDE) value of the most stable AuF4-n(PO3)n- (n = 1-4) ranges from 7.16 to 8.20 eV, higher than the VDE values of the corresponding building blocks AuF4- (7.08 eV) and PO3- (4.69 eV). The adiabatic detachment energy values of these four hyperhalogens exceed 6.00 eV. Possible generation routes for AuF4-n(PO3)n- (n = 1-4) were discussed. The presently designed oxyfluorides not only enriches the family of hyperhalogens, but also demonstrates the great importance of considering the structural transformation during the superhalogen → hyperhalogen design such as for the present Au-P based systems.

  20. Bone marrow-derived Gr1+ cells can generate a metastasis-resistant microenvironment via induced secretion of thrombospondin-1

    PubMed Central

    Catena, Raúl; Bhattacharya, Nandita; Rayes, Tina El; Wang, Suming; Choi, Hyejin; Gao, Dingcheng; Ryu, Seongho; Joshi, Natasha; Bielenberg, Diane; Lee, Sharrell B.; Haukaas, Svein A.; Gravdal, Karsten; Halvorsen, Ole J.; Akslen, Lars A.; Watnick, Randolph S.; Mittal, Vivek

    2013-01-01

    Metastatic tumors have been shown to establish permissive microenvironments for metastases via recruitment of bone marrow (BM)- derived cells. Here, we show that metastasis-incompetent tumors are also capable of generating such microenvironments. However, in these situations the otherwise pro-metastatic Gr1+ myeloid cells create a metastasis-refractory microenvironment via the induction of thrombospondin-1 (Tsp-1) by tumor-secreted prosaposin. (BM)-specific genetic deletion of Tsp-1 abolished the inhibition of metastasis, which was restored by BM transplant from Tsp-1+ donors. We also developed a 5-amino acid peptide from prosaposin as a pharmacological inducer of Tsp-1 in Gr1+ BM cells, which dramatically suppresses metastasis. These results provide mechanistic insights into why certain tumors are deficient in metastatic potential and implicate recruited Gr1+ myeloid cells as the main source of Tsp-1. The results underscore the plasticity of Gr1+ cells, which, depending on the context, promote or inhibit metastasis, and suggest that the peptide could be a potential therapeutic agent against metastatic cancer. PMID:23633432

  1. Inhibitory effect of high NH4(+)-N concentration on anaerobic biotreatment of fresh leachate from a municipal solid waste incineration plant.

    PubMed

    Liu, Zhao; Dang, Yan; Li, Caihua; Sun, Dezhi

    2015-09-01

    Fresh leachate from municipal solid waste (MSW) incineration plants generally contains extremely high NH4(+)-N concentration which could inhibit the bioactivity of microorganisms. The inhibitory effect of high NH4(+)-N concentration on anaerobic biotreatment of fresh leachate from a MSW incineration plant in China has been investigated in this study. The inhibition processes was studied by both static tests and a laboratory-scale expanded granular sludge bed (EGSB) reactor. The specific methanogenic activity (SMA) of the microorganisms in anaerobic granular sludge was inhibited with the NH4(+)-N concentration increasing to 1000mg/L in static tests. As well the chemical oxygen demand (COD) removal efficiency and the methane yield decreased in the EGSB reactor, while the volatile fatty acids (VFAs) accumulated and extracellular polymeric substances (EPS) of the anaerobic granular sludge increased with NH4(+)-N concentration rising to 1000mg/L, without any rebounding during 30days of operation. Decreasing NH4(+)-N concentration to 500mg/L in influent, the COD removal efficiency recovered to about 85% after 26days. 1000mg/L of NH4(+)-N in leachate was suggested to be the inhibition threshold in EGSB reactor. High-throughput sequencing results showed little changes in microbial communities of the sludge for a high NH4(+)-N concentration, indicating that the survival of most microorganisms was not affected under such a condition. It inhibited the bioactivity of the microorganisms, resulting in decrease of the COD removal efficiency.

  2. Plinian vs. phreatomagmatic eruptions at Grímsvötn volcano, Iceland

    NASA Astrophysics Data System (ADS)

    Haddadi, Baptiste; Sigmarsson, Olgeir; Larsen, Guðrún

    2016-04-01

    Grímsvötn is a subglacial central volcano located under the Vatnajökull ice cap, above the assumed centre of the Iceland mantle plume. Historical explosive eruptions are mostly of phreatomagmatic character whereas pure magmatic behaviour may characterize the largest eruptions. What causes this different eruption behaviour is uncertain. Here, we report petrological estimates of crystallization depth and volatile degassing as recorded by sulfur concentrations in melt inclusions (MI) hosted by ferromagnesian minerals and the groundmass glass. Tephra from four eruptions, AD 1823, 1873, 2004 and 2011, were selected. The 2011 and 1873 are the largest known historical eruptions, whereas the 2004 eruption is probably amongst the smallest. The repose time preceding those eruptions is surprisingly similar, or 6 to 7 years, and the major-element compositions are uniform. Plagioclase, clinopyroxene (cpx) and olivine are the three coexisting phases at the liquidus in the quartz-tholeiites of Grímsvötn. The cpx-melt geothermobarometer (Putirka 2008) applied to the 2011 tephra reveals that cpx crystallized over a large range of P from 60 to 640 MPa (depth range: 1.7-18km) and T between 1060 and 1175°C before the Plinian eruption, therefore mobilizing the entire crustal magma system. In contrast, the phreatomagmatic tephra do not record the shallowest crystallization but interestingly all four tephra have identical median entrapment pressure of approximately 400 MPa. Therefore, the depth from which the magma bodies are derived, does not explain the difference in explosivity between those eruptions nor the variable magma volume (V) produced. Sulfur concentrations in MI are only slightly higher in the Plinian products, the difference (10%) being insufficient to explain the different eruption regimes. The ΔS, the difference between the maximum S concentrations in MI and the mean of the groundmass glass for a given eruption, is higher in the Plinian tephra. Based on literature

  3. Electrical Properties Of Volcanic Ash Samples From Grímsvötn

    NASA Astrophysics Data System (ADS)

    Houghton, I. M.; Aplin, K. L.; Nicoll, K. A.; Green, O.; Mather, T. A.

    2012-12-01

    Recent Icelandic eruptions in 2012 and 2011 were associated with sustained charging of the ash plume (Harrison et al., 2010) and significant volcanic lightning (Bennett et al., 2010; Arason et al., 2012). The sustained charging suggests that some charging of the plume is independent of the eruption process, in addition to other electrification mechanisms such as triboelectric or fractoemission processes at the vent, the 'dirty thunderstorm' mechanism if ice forms in the plume, and the internal radioactivity of the plume (Mather and Harrison, 2006; James et al., 2008). We investigate the triboelectric charging of volcanic material using a charged particle apparatus, which allows the charged particles to fall under gravity in a screened metallic cylinder. This apparatus comprises two induction rings connected to sensitive electrometers, which detect charge induced by the falling ash, and a Faraday cup to measure the total ash charge. The release mechanism has been designed to facilitate only self charging of the ash, as is expected in the atmospheric plume. Previous work on triboelectric charging of single-material particle systems has shown that the charging is likely to be determined by the number size distribution (Lacks and Levandovsky, 2007). We present a mass distribution measurement for a sample of volcanic ash provided by the Icelandic Meteorological Office collected 70 km from the crater of the 2011 Grímsvötn eruption. This shows a high proportion of fine particles compared with the volumetric size distribution reported in Piper et al. (2012). Optical microscopy of the different size fractions of the Grímsvötn sample indicates that the composition varies with size. In addition to charge transfer as a function of size, the different substances will triboelectrically interact with each other, which complicates the nature of the charge interactions. To separate the dependence of particle charging on size from composition, particle charging experiments were

  4. Volume dependence of the Grüneisen parameter and maximum compression limit for iron

    NASA Astrophysics Data System (ADS)

    Shanker, J.; Singh, B. P.; Baghel, H. K.

    2007-01-01

    Relationships for the volume dependence of the Grüneisen parameter γ have been used to discuss the behaviour of solids in the limit of infinite pressure ( P→∞). The model recently developed by Burakovsky and Preston (J. Phys. Chem. Solids 65 (2004) 1581) yields γ∞, q∞ and λ∞, the values of Grüneisen parameter γ and its logarithmic volume derivatives q and λ at P→∞, which are found to have fixed values, same for all the solids studied. On the other hand, the thermodynamics of solids at P→∞ formulated by Stacey (Geophys. J. Int. 143 (2000) 621) reveals that γ∞ and pressure derivative of bulk modulus are different for different materials. The empirical formulation for the volume dependence of γ used by Stacey and Davis (Phys. Earth Planet. Intr. 142 (2004) 137) has been shown to be approximately equivalent to the relationship proposed earlier by Al’tshuler et al. (J. Appl. Mech. Tech. Phys. 28 (1987) 129). The shock-pressure data for iron have been used to discuss the maximum compression limit for iron and to emphasize the invalidity of our recent criterion based on the lattice potential energy (Physica B 364 (2005) 186). The Burakovsky-Preston model based on the Thomas-Fermi approximation ( γ∞=1/2 and =5/3) has been found to be more consistent with the shock-compression data. The constraints γ∞>2/3 and >5/3 developed by Stacey are not in agreement with the strong shock compression limit reported for several materials. It is shown here that the Slater formula for γ which was found by Stacey to assume the status of an identity at P→∞ and used by him to derive the constraints for γ∞ and , is invalid when =5/3 It is also pointed out that γ∞=1/2 is to be preferred over γ∞=2/3 because of the thermodynamic constraint >1+ γ∞ developed by Stacey.

  5. Feature Scale Simulation of PECVD of SiO2 in SiH4/N2O Mixture

    NASA Astrophysics Data System (ADS)

    Liu, Xuan; Ge, Jie; Yang, Yi; Song, Yixu; Ren, Tianling

    2014-04-01

    In this paper, to simulate the process of PECVD (plasma enhanced chemical vapor deposition) of SiO2, the plasma chemistry and plasma density of SiH4/N2O mixture have been studied with an inductive coupled plasma model, and the level set methodology has been used to obtain the feature scale variation during the process. In this simulation, the goal is to fill a trench. We studied how ion sputtering and chamber pressure affect the feature scale model. After the simulation, we found that the trench will close up at the top after a few steps, and if we add the ion sputtering into the surface reactions, the trench top will close up a little later. When the chamber pressure is improved, the plasma density will increase, so the trench top will close up earlier. In semiconductor device manufacture, people can control the trench's feature scale through adjusting these two parameters.

  6. Synthesis and aromatase inhibitory evaluation of 4-N-nitrophenyl substituted amino-4H-1,2,4-triazole derivatives.

    PubMed

    Song, Zhidan; Liu, Yanchun; Dai, Zhoutong; Liu, Wei; Zhao, Kai; Zhang, Tongcun; Hu, Yanying; Zhang, Xiuli; Dai, Yujie

    2016-10-01

    In this paper, 13 4-N-nitrophenyl substituted amino-4H-1,2,4-triazole derivatives were synthesized and their aromatase inhibitory activities were measured. The results show that the substitution of the groups on benzyl group can further improve their bioactivity and the compound with Cl on the para position of benzyl has the highest bioactivity (IC50=9.02nM). A QSAR model was constructed from the 13 compounds with genetic function approximation using DS 2.1 package. This model can explain 90.09% of the variance (R(2)Adj), while it can predict 84.95% of the variance (R(2)cv) with the confidence interval of 95%. PMID:27567077

  7. Cross section limits for the Cm248(Mg25,4n-5n)Hs268,269 reactions

    NASA Astrophysics Data System (ADS)

    Dvorak, J.; Brüchle, W.; Düllmann, Ch. E.; Dvorakova, Z.; Eberhardt, K.; Eichler, R.; Jäger, E.; Nagame, Y.; Qin, Z.; Schädel, M.; Schausten, B.; Schimpf, E.; Schuber, R.; Semchenkov, A.; Thörle, P.; Türler, A.; Wegrzecki, M.; Yakushev, A.

    2009-03-01

    We report on an attempt to produce and detect Hs268 and Hs269 in the nuclear fusion reaction Mg25+Cm248 using the gas phase chemistry apparatus COMPACT. No decay chains attributable to the decay of hassium isotopes were observed during the course of this experiment. From the nonobservation of Hs269 we derive a cross section limit of 0.4 pb (63% confidence limit) for the reaction Cm248(Mg25,4n)Hs269 at a center-of-target beam energy of 140 MeV. The evaluated cross section limit for the Cm248(Mg25,5n)Hs268 reaction depends on the assumed half-life of unknown Hs268. Current systematics of the half-lives for even-even Hs isotopes suggests a value of 0.5 s, resulting in a cross section limit of 1.3 pb.

  8. Electronic structure and magnetism in g-C{sub 4}N{sub 3} controlled by strain engineering

    SciTech Connect

    Liu, L. Z.; Liu, X. X.; Wu, X. L. E-mail: paul.chu@cityu.edu.hk; Chu, Paul K. E-mail: paul.chu@cityu.edu.hk

    2015-03-30

    Regulation of magnetism and half-metallicity has attracted much attention because of its potential in spintronics. The magnetic properties and electronic structure of graphitic carbon nitride (g-C{sub 4}N{sub 3}) with external strain are determined theoretically based on the density function theory and many-body perturbation theory (G{sub 0}W{sub 0}). Asymmetric deformation induced by uniaxial strain not only regulates the magnetic characteristics but also leads to a transformation from half-metallicity to metallicity. However, this transition cannot occur in the structure with symmetric deformation induced by biaxial strain. Our results suggest the use of strain engineering in metal-free spintronics applications.

  9. Crystal growth, spectral, structural and optical studies of π-conjugated stilbazolium crystal: 4-bromobenzaldehyde-4'-N'-methylstilbazolium tosylate.

    PubMed

    Krishna Kumar, M; Sudhahar, S; Bhagavannarayana, G; Mohan Kumar, R

    2014-05-01

    Nonlinear optical (NLO) organic compound, 4-bromobenzaldehyde-4'-N'-methylstilbazolium tosylate was synthesized by reflux method. The formation of molecular complex was confirmed from (1)H NMR, FT-IR and FT-Raman spectral analyses. The single crystals were grown by slow evaporation solution growth method and the crystal structure and atomic packing of grown crystal was identified. The morphology and growth axis of grown crystal were determined. The crystal perfection was analyzed using high resolution X-ray diffraction study on (001) plane. Thermal stability, decomposition stages and melting point of the grown crystal were analyzed. The optical absorption coefficient (α) and energy band gap (E(g)) of the crystal were determined using UV-visible absorption studies. Second harmonic generation efficiency of the grown crystal was examined by Kurtz powder method with different particle size using 1064 nm laser. Laser induced damage threshold study was carried out for the grown crystal using Nd:YAG laser. PMID:24531108

  10. Measurements of the dielectric and viscoelastic constants in mixtures of 4,4'-n-octyl-cyanobiphenyl and biphenyl.

    PubMed

    Oswald, Patrick; Scalliet, Camille

    2014-03-01

    We performed measurements of the dielectric constants, splay elastic constant, and rotational viscosity of the nematic phase of mixtures of 4,4'-n-octyl-cyanobiphenyl (8CB) and biphenyl (BP). In contrast with previous results of DasGupta et al. [Phys. Rev. E 63, 041703 (2001); Phys. Lett. A 288, 323 (2001)], we do not find any anomaly of these constants when the smectic-A phase is approached at all concentrations of BP. These results are compatible with recent calorimetric measurements of Denolf et al. [Phys. Rev. Lett. 97, 107801 (2006); Phys. Rev. E 76, 051702 (2007)] and the absence of a tricritical point in the phase diagram. The origin of the anomalies observed by DasGupta et al. at large concentration of BP is also briefly discussed and a likely explanation in terms of biphenyl evaporation is proposed.

  11. A Termolecular Reaction Mechanism for Nitrogen Incorporation in Aerosol Produced by Far UV Irradiation of CH4-N2 Atmospheres

    NASA Astrophysics Data System (ADS)

    Hicks, R. K.; Trainer, M. G.; Jimenez, J. L.; Yung, Y. L.; Toon, O. B.; Tolbert, M. A.

    2012-12-01

    Results from the Aerosol Collector and Pyrolyser located onboard the Huygens lander reveal the presence of carbon and nitrogen in Titan's aerosols. Nitrogen incorporation is thought to be initiated by energy sources strong enough to break the N-N triple bond of molecular nitrogen (9.8eV). Such energy sources include extreme UV photons (λ <120 nm) and electrons from Saturn's magnetosphere. Less energetic photons in the far UV (120-200 nm) penetrate to the stratosphere of Titan and are only expected to affect hydrocarbon photochemistry there. However, recent results from our laboratory indicate a surprising amount of nitrogen incorporation- up to 16% by mass- in Titan aerosol analog produced by photochemistry initiated by far UV irradiation of CH4/N2 mixtures. The termolecular reaction CH + N2 + M --> HCN2 has been proposed to account for this observation. Here, we test this hypothesis by using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) to measure the mass loading and chemical composition of aerosol produced at a range of pressures from roughly 0.1 to 1 atm. Even though these gas mixtures spanned an order of magnitude in pressure, they experienced the same residence time in the photochemical chamber and had the same methane optical depth. We report a 150% increase in aerosol mass loading across the range of pressures studied, indicating that the mechanism controlling the total mass produced depends on pressure. We also report an overall increase with pressure in the ratio of nitrogen-bearing organic species to hydrocarbon-only species. These observations support the hypothesis that the termolecular reaction above is responsible for the incorporation of nitrogen into Titan aerosol analog produced from CH4/N2 gas mixtures irradiated in the far UV. These findings have implications for our understanding of the evolution of Titan's atmosphere, and the atmospheric synthesis of biologically relevant N-containing molecules.

  12. Improvement of RNA-SIP by pyrosequencing to identify putative 4-n-nonylphenol degraders in activated sludge.

    PubMed

    Zemb, O; Lee, M; Gutierrez-Zamora, M L; Hamelin, J; Coupland, K; Hazrin-Chong, N H; Taleb, I; Manefield, M

    2012-03-01

    Nonylphenols (NP) have estrogenic potential because of their phenolic ring, but the organisms involved in the degradation of this alkylated phenol remain unidentified. Using 16S ribosomal RNA (rRNA)-based stable isotope probing (SIP) and a new method based on pyrosequencing, we identified the bacteria involved in the degradation of the aromatic ring of [U-ring-(13)C] 4-n-NP in aerobic sludge. The first order degradation rate of 4-n-NP was 5.5d(-1). Single strand conformation polymorphism of density-separated labeled and unlabeled 16S rRNA showed significant differences and enabled selection of four representative fractions for pyrosequencing. Nineteen phylotypes showed a significant enrichment in the heavy fraction in the labeled pulse. The relative abundances of these phylotypes were combined with the RNA concentration of each fraction to yield a simple model of the distribution of each phylotype across the gradient. This model was used to estimate the percentage of labeling for each phylotype. The sequences showing the highest labeling (11%) were closely related to Afipia sp. but represented only 2 % of the RNA in the heavy fraction of the labeled pulse. The sequences representing the largest proportion of the RNA in the heavy fraction were related to Propionibacterium acnes and Frateuria aurantia, which are known to possess enzymes for phenol degradation. The model shows that despite Afipia having the highest (13)C enrichment, other species encoding phenol degradation pathways are responsible for more (13)C incorporation. Last, we showed that some species represent 12% of the total RNA but contain only 1% (13)C above natural abundance.

  13. Scaling of the magnetic Grüneisen ratio near quantum critical point

    NASA Astrophysics Data System (ADS)

    Tokiwa, Yoshi

    2014-03-01

    The magnetic Grüneisen ratio ΓH = (1/T)dT/dH is the most sensitive probe of quantum criticality. Its divergence signals the underlying instability. We have studied quantum criticality in the frustrated Kondo lattice system YbAgGe and the heavy fermion superconductor CeCoIn5 by high-precision magnetocaloric effect measurements. In the former, NFL behavior appears around a metamagnetic spin-flop transition between two symmetry broken phases. Previously, it was unclear how the two ordered phases are related to the NFL state. Here, we propose a novel quantum bicritical point (QBCP) scenario, which is distinct from either quantum critical end point or ordinary QCPs with single symmetry broken phase. The observed scaling behavior of ΓH and its characteristic asymmetry across the critical field are consistent with a QBCP scenario. We also report a possible violation of Wiedemann-Franz law at the QBCP in YbAgGe. In CeCoIn5 indications of a quantum critical field hidden inside the superconducting (SC) phase have been extensively debated. We show ΓH data and scaling analysis in the normal state, which surprisingly suggests a zero-field QCP. Anomalous behaviors of ΓH and specific heat within the SC state further support this conclusion.

  14. Heat treatment temperature influence on ASTM A890 GR 6A super duplex stainless steel microstructure

    SciTech Connect

    Martins, Marcelo; E-mail: marcelo.martins@sulzer.com; Casteletti, Luiz Carlos

    2005-09-15

    Duplex and super duplex stainless steels are ferrous alloys with up to 26% chromium, 8% nickel, 5% molybdenum and 0.3% nitrogen, which are largely used in applications in media containing ions from the halogen family, mainly the chloride ion (Cl{sup -}). The emergence of this material aimed at substituting Copper-Nickel alloys (Cupro-Nickel) that despite presenting good corrosion resistance, has mechanical properties quite inferior to steel properties. The metallurgy of duplex and super duplex stainless steel is complex due to high sensitiveness to sigma phase precipitation that becomes apparent, due to the temperatures they are exposed on cooling from solidification as well as from heat treatment processes. The objective of this study was to verify the influence of heat treating temperatures on the microstructure and hardness of ASTM A890/A890M Gr 6A super duplex stainless steel type. Microstructure control is of extreme importance for castings, as the chemical composition and cooling during solidification inevitably provide conditions for precipitation of sigma phase. Higher hardness in these materials is directly associated to high sigma phase concentration in the microstructure, precipitated in the ferrite/austenite interface. While heat treatment temperature during solution treatment increases, the sigma phase content in the microstructure decreases and consequently, the material hardness diminishes. When the sigma phase was completely dissolved by the heat treatment, the material hardness was influenced only due to ferrite and austenite contents in the microstructure.

  15. Leak before break evaluation for main steam piping system made of SA106 Gr.C

    SciTech Connect

    Yang, Kyoung Mo; Jee, Kye Kwang; Pyo, Chang Ryul; Ra, In Sik

    1997-04-01

    The basis of the leak before break (LBB) concept is to demonstrate that piping will leak significantly before a double ended guillotine break (DEGB) occurs. This is demonstrated by quantifying and evaluating the leak process and prescribing safe shutdown of the plant on the basis of the monitored leak rate. The application of LBB for power plant design has reduced plant cost while improving plant integrity. Several evaluations employing LBB analysis on system piping based on DEGB design have been completed. However, the application of LBB on main steam (MS) piping, which is LBB applicable piping, has not been performed due to several uncertainties associated with occurrence of steam hammer and dynamic strain aging (DSA). The objective of this paper is to demonstrate the applicability of the LBB design concept to main steam lines manufactured with SA106 Gr.C carbon steel. Based on the material properties, including fracture toughness and tensile properties obtained from the comprehensive material tests for base and weld metals, a parametric study was performed as described in this paper. The PICEP code was used to determine leak size crack (LSC) and the FLET code was used to perform the stability assessment of MS piping. The effects of material properties obtained from tests were evaluated to determine the LBB applicability for the MS piping. It can be shown from this parametric study that the MS piping has a high possibility of design using LBB analysis.

  16. Evaluating climate change effects on runoff by statistical downscaling and hydrological model GR2M

    NASA Astrophysics Data System (ADS)

    Okkan, Umut; Fistikoglu, Okan

    2014-07-01

    The main purpose of this study is to evaluate the impacts of climate change on Izmir-Tahtali freshwater basin, which is located in the Aegean Region of Turkey. For this purpose, a developed strategy involving statistical downscaling and hydrological modeling is illustrated through its application to the basin. Prior to statistical downscaling of precipitation and temperature, the explanatory variables are obtained from National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis data set. All possible regression approach is used to establish the most parsimonious relationship between precipitation, temperature, and climatic variables. Selected predictors have been used in training of artificial neural networks-based downscaling models and the trained models with the obtained relationships have been operated to produce scenario precipitation and temperature from the simulations of third Generation Coupled Climate Model. Biases from downscaled outputs have been reduced after downscaling process. Finally, the corrected downscaled outputs have been transformed to runoff by means of a monthly parametric hydrological model GR2M to assess the probable impacts of temperature and precipitation changes on runoff. According to the A1B climate scenario results, statistically significant trends are foreseen for precipitation, temperature, and runoff in the study basin.

  17. Triboelectric Charging of Volcanic Ash from the 2011 Grímsvötn Eruption

    NASA Astrophysics Data System (ADS)

    Houghton, Isobel M. P.; Aplin, Karen L.; Nicoll, Keri A.

    2013-09-01

    The plume from the 2011 eruption of Grímsvötn was highly electrically charged, as shown by the considerable lightning activity measured by the United Kingdom Met Office’s low-frequency lightning detection network. Previous measurements of volcanic plumes have shown that ash particles are electrically charged up to hundreds of kilometers away from the vent, which indicates that the ash continues to charge in the plume [R. G. Harrison, K. A. Nicoll, Z. Ulanowski, and T. A. Mather, Environ. Res. Lett. 5, 024004 (2010)1748-932610.1088/1748-9326/5/2/024004; H. Hatakeyama J. Meteorol. Soc. Jpn. 27, 372 (1949)JMSJAU0026-1165]. In this Letter, we study triboelectric charging of different size fractions of a sample of volcanic ash experimentally. Consistently with previous work, we find that the particle size distribution is a determining factor in the charging. Specifically, our laboratory experiments demonstrate that the normalized span of the particle size distribution plays an important role in the magnitude of charging generated. The influence of the normalized span on plume charging suggests that all ash plumes are likely to be charged, with implications for remote sensing and plume lifetime through scavenging effects.

  18. Triboelectric charging of volcanic ash from the 2011 Grímsvötn eruption.

    PubMed

    Houghton, Isobel M P; Aplin, Karen L; Nicoll, Keri A

    2013-09-13

    The plume from the 2011 eruption of Grímsvötn was highly electrically charged, as shown by the considerable lightning activity measured by the United Kingdom Met Office's low-frequency lightning detection network. Previous measurements of volcanic plumes have shown that ash particles are electrically charged up to hundreds of kilometers away from the vent, which indicates that the ash continues to charge in the plume [R. G. Harrison, K. A. Nicoll, Z. Ulanowski, and T. A. Mather, Environ. Res. Lett. 5, 024004 (2010); H. Hatakeyama J. Meteorol. Soc. Jpn. 27, 372 (1949)]. In this Letter, we study triboelectric charging of different size fractions of a sample of volcanic ash experimentally. Consistently with previous work, we find that the particle size distribution is a determining factor in the charging. Specifically, our laboratory experiments demonstrate that the normalized span of the particle size distribution plays an important role in the magnitude of charging generated. The influence of the normalized span on plume charging suggests that all ash plumes are likely to be charged, with implications for remote sensing and plume lifetime through scavenging effects. PMID:24074123

  19. Grünwald-Letnikov operators for fractional relaxation in Havriliak-Negami models

    NASA Astrophysics Data System (ADS)

    Garrappa, Roberto

    2016-09-01

    Several classes of differential and integral operators of non integer order have been proposed in the past to model systems exhibiting anomalous and hereditary properties. A wide range of complex and heterogeneous systems are described in terms of laws of Havriliak-Negami type involving a special fractional relaxation whose behavior in the time-domain can not be represented by any of the existing operators. In this work we introduce new integral and differential operators for the description of Havriliak-Negami models in the time-domain. In particular we propose a formulation of Grünwald-Letnikov type which turns out to be effective not only to provide a theoretical characterization of the operators associated to Havriliak-Negami systems but also for computational purposes. We study some properties of the new operators and, by means of some numerical experiments, we present their use in practical computation and we show the superiority with respect to the few other approaches previously proposed in literature.

  20. Adsorption of 4-n-Nonylphenol and Bisphenol-A on Magnetic Reduced Graphene Oxides: A Combined Experimental and Theoretical Studies.

    PubMed

    Jin, Zhongxiu; Wang, Xiangxue; Sun, Yubing; Ai, Yuejie; Wang, Xiangke

    2015-08-01

    Adsorption of 4-n-nonylphenol (4-n-NP) and bisphenol A (BPA) on magnetic reduced graphene oxides (rGOs) as a function of contact time, pH, ionic strength and humic acid were investigated by batch techniques. Adsorption of 4-n-NP and BPA were independent of pH at 3.0- 8.0, whereas the slightly decreased adsorption was observed at pH 8.0-11.0. Adsorption kinetics and isotherms of 4-n-NP and BPA on magnetic rGOs can be satisfactorily fitted by pseudo-second-order kinetic and Freundlich model, respectively. The maximum adsorption capacities of magnetic rGOs at pH 6.5 and 293 K were 63.96 and 48.74 mg/g for 4-n-NP and BPA, respectively, which were significantly higher than that of activated carbon. Based on theoretical calculations, the higher adsorption energy of rGOs + 4-n-NP was mainly due to π-π stacking and flexible long alkyl chain of 4-n-NP, whereas adsorption of BPA on rGOs was energetically favored by a lying-down configuration due to π-π stacking and dispersion forces, which was further demonstrated by FTIR analysis. These findings indicate that magnetic rGOs is a promising adsorbent for the efficient elimination of 4-n-NP/BPA from aqueous solutions due to its excellent adsorption performance and simple magnetic separation, which are of great significance for the remediation of endocrine-disrupting chemicals in environmental cleanup. PMID:26161689

  1. A novel yellow-emitting SrAlSi4N7:Ce3+ phosphor for solid state lighting: Synthesis, electronic structure and photoluminescence properties

    NASA Astrophysics Data System (ADS)

    Ruan, Jian; Xie, Rong-Jun; Funahashi, Shiro; Tanaka, Yoshinori; Takeda, Takashi; Suehiro, Takayuki; Hirosaki, Naoto; Li, Yuan-Qiang

    2013-12-01

    Ce3+-doped and Ce3+/Li+-codoped SrAlSi4N7 phosphors were synthesized by gas pressure sintering of powder mixtures of Sr3N2, AlN, α-Si3N4, CeN and Li3N. The phase purity, electronic crystal structure, photoluminescence properties of SrAlSi4N7:Ce3+(Ce3+/Li+) were investigated in this work. The band structure calculated by the DMol3 code shows that SrAlSi4N7 has a direct band gap of 3.87 eV. The single crystal analysis of Ce3+-doped SrAlSi4N7 indicates a disordered Si/Al distribution and nitrogen vacnacy defects. SrAlSi4N7 was identified as a major phase of the fired powders, and Sr5Al5Si21N35O2 and AlN as minor phases. Both Ce3+ and Ce3+/Li+ doped SrAlSi4N7 phosphors can be efficiently excited by near-UV or blue light and show a broadband yellow emission peaking around 565 nm. A highest external quantum efficiency of 38.3% under the 450 nm excitation was observed for the Ce3+/Li+-doped SrAlSi4N7 (5 mol%). A white light LED lamp with color temperature of 6300 K and color rendering index of Ra=78 was achieved by combining Sr0.97Al1.03Si3.997N\\94\\maccounttest14=t0005_18193 7:Ce3+0.03 with a commercial blue InGaN chip. It indicates that SrAlSi4N7:Ce3+ is a promising yellow emitting down-conversion phosphor for white LEDs.

  2. Balloon Angioplasty – The Legacy of Andreas Grüntzig, M.D. (1939–1985)

    PubMed Central

    Barton, Matthias; Grüntzig, Johannes; Husmann, Marc; Rösch, Josef

    2014-01-01

    In 1974, at the Medical Policlinic of the University of Zürich, German-born physician-scientist Andreas Grüntzig (1939–1985) for the first time applied a balloon-tipped catheter to re-open a severely stenosed femoral artery, a procedure, which he initially called “percutaneous transluminal dilatation”. Balloon angioplasty as a therapy of atherosclerotic vascular disease, for which Grüntzig and Charles T. Dotter (1920–1985) received a nomination for the Nobel Prize in Physiology or Medicine in 1978, became one of the most successful examples of translational medicine in the twentieth century. Known today as percutaneous transluminal angioplasty (PTA) in peripheral arteries or percutaneous transluminal coronary angioplasty (PTCA) or percutaneous coronary intervention (PCI) in coronary arteries, balloon angioplasty has become the method of choice to treat patients with acute myocardial infarction or occluded leg arteries. On the occasion of the 40th anniversary of balloon angioplasty, we summarize Grüntzig’s life and career in Germany, Switzerland, and the United States and also review the developments in vascular medicine from the 1890s to the 1980s, including Dotter’s first accidental angioplasty in 1963. The work of pioneers of catheterization, including Pedro L. Fariñas in Cuba, André F. Cournand in France, Werner Forssmann, Werner Porstmann and Eberhard Zeitler in Germany, António Egas Moniz and Reynaldo dos Santos in Portugal, Sven-Ivar Seldinger in Sweden, and Barney Brooks, Thomas J. Fogarty, Melvin P. Judkins, Richard K. Myler, Dickinson W. Richards, and F. Mason Sones in the United States, is discussed. We also present quotes by Grüntzig and excerpts from his unfinished autobiography, statements of Grüntzig’s former colleagues and contemporary witnesses, and have included hitherto unpublished historic photographs and links to archive recordings and historic materials. This year, on June 25, 2014, Andreas Grüntzig would have celebrated

  3. Hepatic fungal infection in a young beagle with unrecognised hereditary cobalamin deficiency (Imerslund-Gräsbeck syndrome).

    PubMed

    Kook, P H; Drögemüller, M; Leeb, T; Hinden, S; Ruetten, M; Howard, J

    2015-02-01

    A 12-month-old beagle presented for anorexia, pyrexia and vomiting. The dog had been treated intermittently with antibiotics and corticosteroids for inappetence and lethargy since five months of age. Previous laboratory abnormalities included macrocytosis and neutropenia. At presentation, the dog was lethargic, febrile and thin. Laboratory examination findings included anaemia, a left shift, thrombocytopenia, hypoglycaemia and hyperbilirubinaemia. Multiple, small, hypoechoic, round hepatic lesions were observed on abdominal ultrasound. Cytological examination of hepatic fine needle aspirates revealed a fungal infection and associated pyogranulomatous inflammation. The dog's general condition deteriorated despite supportive measures and treatment with fluconazole, and owners opted for euthanasia before hypocobalaminaemia was identified. Subsequent genomic analysis revealed a CUBN:c.786delC mutation in a homozygous state, confirming hereditary cobalamin malabsorption (Imerslund-Gräsbeck syndrome). Similar to human infants, dogs with Imerslund-Gräsbeck syndrome may rarely be presented for infectious diseases, distracting focus from the underlying primary disorder. PMID:25131805

  4. Gabapentin Extended-Release - Depomed: Gabapentin ER, Gabapentin Gastric Retention, Gabapentin GR.

    PubMed

    2007-01-01

    Depomed is developing an extended-release (ER) oral formulation of gabapentin, a GABA receptor agonist commonly used for the treatment of epilepsy and seizures, neuropathic pain and hot flushes. Gabapentin ER is based on the company's proprietary AcuForm drug delivery technology, which is part of the Gastric Retention (GR) family of technologies; this offers improved drug absorption and bioavailability compared with the existing immediate-release formulation of gabapentin (Neurontin), making gabapentin ER suitable for twice-daily dosing. The product is in clinical development for the treatment of postherpetic neuralgia and diabetic neuropathies in the US. Additionally, Depomed has commenced a phase II trial of gabapentin ER in postmenopausal patients with hot flushes. Depomed's AcuForm platform is based on polymer technology that provides targeted drug delivery for a variety of compounds. Following ingestion, AcuForm tablets swell and are retained for 6-8 hours in the stomach, enabling controlled and prolonged release of gabapentin to the upper intestinal tract; this extends the time of drug delivery to the small intestine for complete and safe elimination via the lower intestinal track. Gabapentin ER is available for licensing. Depomed acquired exclusive development and commercialisation rights to gabapentin ER in September 2003 via its subsidiary, Depomed Development Ltd (DDL). Depomed is not required to pay upfront license fees, but will make royalty and milestone payments to DDL upon successful commercialisation of gabapentin ER. Gabapentin ER was originally developed by DDL, a joint venture between Depomed and Elan established in January 2000 to design products using the GR family of technologies. However, in efforts to restructure joint venture relationships, Elan withdrew from operational involvement of DDL in September 2003, and Depomed has gained full ownership of DDL. Depomed sublicensed exclusive rights to a US patent (held by the University of Rochester

  5. The antihypertensive profile of the angiotensin AT1 receptor antagonist, GR138950, and the influence of potential homeostatic compensatory mechanisms in renal hypertensive rats

    PubMed Central

    Anderson, Ian K; Drew, Geoffrey M

    1998-01-01

    The cardiovascular profile of the angiotensin AT1 receptor antagonist, GR138950, and the influence of potential compensatory homeostatic mechanisms on this profile, were investigated in renal artery ligated hypertensive (RALH) rats.GR138950 caused a marked reduction in blood pressure associated with immediate tachycardia in conscious RALH rats. The antihypertensive action of GR138950 appeared biphasic; an immediate fall in blood pressure, which plateaued within 1 h, and which was followed by a further slow decline that reached maximum between 5–7 h after administration.The tachycardia caused by GR138950 was attenuated by atenolol and was abolished by combined pretreatment with atenolol and atropine methyl nitrate. However, the antihypertensive profile of GR138950 was unchanged by these pretreatments.The resting blood pressure and the antihypertensive effect of GR138950, in RALH rats, were unaffected by the vasopressin V1 receptor antagonist, [β-mercapto-β,β-cyclopentamethylene propionyl1-O-Me-Tyr2,Arg8]-vasopressin. Thus, vasopressinergic mechanisms are not involved in either maintaining blood pressure in RALH rats, or in compensating for the fall in blood pressure caused by GR138950.In anaesthetized RALH rats, GR138950 caused a marked fall in blood pressure that was accompanied by an increase in heart rate along with sustained increases in renal and splanchnic sympathetic nerve activity.In summary, the biphasic fall in blood pressure evoked by GR138950 in RALH rats can not be explained on the basis of changes in autonomic control of the heart, alteration of vasopressin-mediated vasoconstrictor mechanisms or overall suppression of central sympathetic outflow. Rather, increased vasoconstrictor tone might serve to oppose the initial fall in blood pressure. PMID:9863652

  6. Implications for future activity of Grímsvötn volcano, Iceland, from compositional time series of historical tephra

    NASA Astrophysics Data System (ADS)

    Carpentier, Marion; Sigmarsson, Olgeir; Larsen, Gudrun

    2014-05-01

    The nature of future eruptions of active volcanoes is hard to predict. Improved understanding of the past volcanic activity is probably the best way to infer future eruptive scenarios. The most active volcano in Iceland, Grímsvötn, last erupted in 2011 with consequences for habitants living close to the volcano and aviation in the North-Atlantic. In an effort to better understand the magmatic system of the volcano, we have investigated the compositions of 23 selected tephra layers representing the last 8 centuries of volcanic activity at Grímsvötn. The tephra was collected in the ablation area of outlet glaciers from Vatnajökull ice cap. The ice-conserved tephra are less prone to alteration than those exposed in soil sections. Major element analyses are indistinguishable and of quartz-normative tholeiite composition, and Sr and Nd isotope ratios are constant. In contrast, both trace element concentrations (Th range from 0.875 ppm to 1.37 ppm and Ni from 28.5 ppm to 56.6 ppm) in the basalts and Pb isotopes show small but significant variations. The high-precision analyses of Pb isotope ratios allow the identification of tephra samples (3 in total) with more radiogenic ratios than the bulk of the samples. The tephra of constant isotope ratios show linear increase in incompatible element concentrations with time. The rate of increasing concentrations permits exploring possible future scenarios assuming that the magmatic system beneath the volcano follows the established historical evolution. Assuming similar future behaviour of the magma system beneath Grímsvötn volcano, the linear increase in e.g. Th concentration suggests that the volcano is likely to principally produce basalts for the next 500-1000 years. Evolution of water concentration will most likely follow those of incompatible elements with consequent increases in explosiveness of future Grímsvötn eruptions.

  7. Induction of PGF2α Synthesis by Cortisol Through GR Dependent Induction of CBR1 in Human Amnion Fibroblasts

    PubMed Central

    Guo, Chunming; Wang, Wangsheng; Liu, Chao

    2014-01-01

    Abundant evidence indicates a pivotal role of prostaglandin F2α (PGF2α) in human parturition. Both the fetal and maternal sides of the fetal membranes synthesize PGF2α. In addition to the synthesis of PGF2α from PGH2 by PGF synthase (PGFS), PGF2α can also be converted from PGE2 by carbonyl reductase 1 (CBR1). Here, we showed that there was concurrent increased production of cortisol and PGF2α in association with the elevation of CBR1 in human amnion obtained at term with labor versus term without labor. In cultured primary human amnion fibroblasts, cortisol (0.01–1μM) increased PGF2α production in a concentration-dependent manner, in parallel with elevation of CBR1 levels. Either siRNA-mediated knockdown of glucocorticoid receptor (GR) expression or GR antagonist RU486 attenuated the induction of CBR1 by cortisol. Chromatin immunoprecipitation (ChIP) showed an increased enrichment of both GR and RNA polymerase II to CBR1 promoter. Knockdown of CBR1 expression with siRNA or inhibition of CBR1 activity with rutin decreased both basal and cortisol-stimulated PGF2α production in human amnion fibroblasts. In conclusion, CBR1 may play a critical role in PGF2α synthesis in human amnion fibroblasts, and cortisol promotes the conversion of PGE2 into PGF2α via GR-mediated induction of CBR1 in human amnion fibroblasts. This stimulatory effect of cortisol on CBR1 expression may partly explain the concurrent increases of cortisol and PGF2α in human amnion tissue with labor, and these findings may account for the increased production of PGF2α in the fetal membranes prior to the onset of labor. PMID:24654784

  8. Resistance to intestinal Entamoeba histolytica infection is conferred by innate immunity and Gr-1+ cells.

    PubMed

    Asgharpour, Amon; Gilchrist, Carol; Baba, Duza; Hamano, Shinjiro; Houpt, Eric

    2005-08-01

    Establishment of intestinal infection with Entamoeba histolytica depends on the mouse strain; C57BL/6 mice are highly resistant, and C3H/HeJ mice are relatively susceptible. We found that resistance to intestinal infection was independent of lymphocyte activity or H-2 haplotype and occurred in the first hours to days postchallenge according to in vivo imaging. At 18 h postchallenge, the ceca of resistant C57BL/6 mice were histologically unremarkable, in contrast to the severe inflammation observed in susceptible C3H/HeJ mice. Comparison of cecal gene expression in C3H/HeJ and C57BL/6 mice demonstrated that there was parasite-induced upregulation of proinflammatory and neutrophil chemotaxis transcripts and there was downregulation of transforming growth factor beta signaling molecules. Pretreatment with dexamethasone abrogated the partial resistance of C3H/HeJ or CBA mice through an innate, lymphocyte-independent mechanism, but it had no effect on the high-level resistance of C57BL/6 mice. Similarly, administration of a neutrophil-depleting anti-Gr-1 monoclonal antibody (RB6-8C5) decreased the partial resistance of CBA mice and led to severe pathology compared to control antibody-treated mice, but it had no effect on C57BL/6 resistance. These data indicate that there are discrete mechanisms of innate resistance to E. histolytica depending on the host background and, in contrast to other reports, imply that neutrophils are protective and not damaging in intestinal amebiasis.

  9. Imerslund-Gräsbeck syndrome (selective vitamin B12 malabsorption with proteinuria)

    PubMed Central

    Gräsbeck, Ralph

    2006-01-01

    Imerslund-Gräsbeck syndrome (IGS) or selective vitamin B12 (cobalamin) malabsorption with proteinuria is a rare autosomal recessive disorder characterized by vitamin B12 deficiency commonly resulting in megaloblastic anemia, which is responsive to parenteral vitamin B12 therapy and appears in childhood. Other manifestations include failure to thrive and grow, infections and neurological damage. Mild proteinuria (with no signs of kidney disease) is present in about half of the patients. Anatomical anomalies in the urinary tract were observed in some Norwegian patients. Vitamin B12 absorption tests show low absorption, not corrected by administration of intrinsic factor. The symptoms appear from 4 months (not immediately after birth as in transcobalamin deficiency) up to several years after birth. The syndrome was first described in Finland and Norway where the prevalence is about 1:200,000. The cause is a defect in the receptor of the vitamin B12-intrinsic factor complex of the ileal enterocyte. In most cases, the molecular basis of the selective malabsorption and proteinuria involves a mutation in one of two genes, cubilin (CUBN) on chromosome 10 or amnionless (AMN) on chromosome 14. Both proteins are components of the intestinal receptor for the vitamin B12-intrinsic factor complex and the receptor mediating the tubular reabsorption of protein from the primary urine. Management includes life-long vitamin B12 injections, and with this regimen, the patients stay healthy for decades. However, the proteinuria persists. In diagnosing this disease, it is important to be aware that cobalamin deficiency affects enterocyte function; therefore, all tests suggesting general and cobalamin malabsorption should be repeated after abolishment of the deficiency. PMID:16722557

  10. The 2007 Nobel Prize in Physics: Albert Fert and Peter Grünberg

    NASA Astrophysics Data System (ADS)

    Cros, Vincent; Fert, Albert; Sénéor, Pierre; Petroff, Frédéric

    GMR and spintronics take their roots in the pioneering work of Albert Fert around 1970 on the influence of the spin on the mobility of electrons in ferromagnetic materials [1]. After having experimentally demonstrated that, in a ferromagnetic metal, the electrons of opposite spin directions (spin up and spin down along the magnetization axis) carry different currents (as originally suggested by Mott), Fert worked out the well known two current model of the electrical conduction in ferromagnetic metals. He also showed that very large spin asymmetries of the conduction can be obtained by doping the ferromagnetic metal with impurities selected to scatter very differently the spin up and spin down electrons (iron or cobalt impurities in nickel, for example, scatter the spin down electrons 20 times more strongly than the spin up electrons). Moreover, some experiments of Fert on ternary alloys were already introducing the idea that he will exploit later to produce the GMR effects. He showed that the resistivity of a ternary alloy, for example N 1-x (A x-y ,B y ), is strongly enhanced if the scattering by the impurities A and B have inverse spin asymmetries. Replacing the impurities A and B by magnetic layers A and B, one equally expects a large enhancement of the resistivity when their magnetizations are in opposite directions, which the basic concept of the GMR. However, this concept can work only if the thickness of the layers is in the nanometer range. The fabrication of multilayers with thicknesses in this range became technologically possible in the mid-eighties and, in particular, the growth of magnetic multilayers by Molecular Beam Epitaxy (MBE) was developed in the groups of Albert Fert and Peter Grünberg.

  11. Computational investigation on thermal conductivity behavior of Al 6061-SiC-Gr hybrid metal matrix composites

    NASA Astrophysics Data System (ADS)

    Krishna, S. A. Mohan; Shridhar, T. N.; Krishnamurthy, L.

    2015-10-01

    Metal matrix composites (MMCs) are regarded to be one of the most principal classifications in composite materials. The thermal characterization of hybrid MMCs has become increasingly important in a wide range of applications. Thermal conductivity is one of the most important properties of MMCs. Since nearly all MMCs are used in various temperature ranges, measurement of thermal conductivity as a function of temperature is necessary in order to know the behavior of the material. In the present research, evaluation of thermal conductivity has been accomplished for aluminum alloy (Al) 6061, silicon carbide (SiC) and graphite (Gr) hybrid MMCs from room temperature to 300∘C. Al-based composites reinforced with SiC and Gr particles have been prepared by stir casting technique. The thermal conductivity behavior of hybrid composites with different percentage compositions of reinforcements has been investigated using laser flash technique. The results have indicated that the thermal conductivity of the different compositions of hybrid MMCs decreases by the addition of Gr with SiC and Al 6061. Few empirical models have been validated concerning with the evaluation of thermal conductivity of composites. Using the experimental values namely density, thermal conductivity, specific heat capacity and enthalpy at varying temperature ranges, computational investigation has been carried out to evaluate the thermal gradient and thermal flux.

  12. Computational investigation on thermal expansivity behavior of Al 6061-SiC-Gr hybrid metal matrix composites

    NASA Astrophysics Data System (ADS)

    Mohan Krishna, S. A.; Shridhar, T. N.; Krishnamurthy, L.

    2015-08-01

    Metal matrix composites (MMCs) have been regarded as one of the most principal classifications in composite materials. The thermal characterization of hybrid MMCs has been increasingly important in a wide range of applications. The coefficient of thermal expansion is one of the most important properties of MMCs. Since nearly all MMCs are used in various temperature ranges, measurement of coefficient of thermal expansion (CTE) as a function of temperature is necessary in order to know the behavior of the material. In this research paper, the evaluation of thermal expansivity has been accomplished for Al 6061, silicon carbide (SiC) and Graphite (Gr) hybrid MMCs from room temperature to 300°C. Aluminum (Al)-based composites reinforced with SiC and Gr particles have been prepared by stir casting technique. The thermal expansivity behavior of hybrid composites with different percentage compositions of reinforcements has been investigated. The results have indicated that the thermal expansivity of the different compositions of hybrid MMCs decreases by the addition of Gr with SiC and Al 6061. Few empirical models have been validated for the evaluation of thermal expansivity of composites. Using the experimental values namely modulus of elasticity, Poisson's ratio and thermal expansivity, computational investigation has been carried out to evaluate the thermal parameters namely thermal displacement, thermal strain and thermal stress.

  13. Purification of a dimeric arginine deiminase from Enterococcus faecium GR7 and study of its anti-cancerous activity.

    PubMed

    Kaur, Baljinder; Kaur, Rajinder

    2016-09-01

    The arginine deiminase (ADI, E.C 3.5.3.6) - a key enzyme of ADI pathway of Enterococcus faecium GR7 was purified to homogeneity. A sequential purification strategy involving ammonium sulfate fractionation, molecular sieve followed by Sephadex G-100 gel filtration was applied to the crude culture filtrate to obtain a pure enzyme preparation. The enzyme was purified with a fold of 16.92 and showed a final specific activity of 76.65IU/mg with a 49.17% yield. The dimeric ADI has a molecular mass of about 94,364.929Da, and comprises of hetrodimers of 49.1kDa and 46.5kDa as determined by MALDI-TOF and PAGE analysis. To assess anti-cancerous activity of ADI by MTT assay was carried out against cancer cell lines (MCF-7, Sp2/0-Ag14 and Hep-G2). Purified ADI exhibited the most profound antiproliferative activity against Hep-G2 cells; with half-maximal inhibitory concentration (IC50) of 1.95μg/ml. Purified ADI from E. faecium GR7 was observed to induce apoptosis in the Hep-G2 cells by DNA fragmentation assay. Our findings suggest the possibility of a future use of ADI from E. faecium GR7 as a potential anticancer drug.

  14. Comparative study on the inclusion behavior between meso-tetrakis(4- N-ethylpyridiniurmyl)porphyrin and β-cyclodextrin derivatives

    NASA Astrophysics Data System (ADS)

    Xiliang, Guo; Shaomin, Shuang; Chuan, Dong; Feng, Feng; Wong, M. S.

    2005-01-01

    5,10,15,20-Tetrakis(4- N-ethylpyridiniurmyl)porphyrin (TEPyP) formed 1:1 stoichiometry inclusion complexes with β-cyclodextrin (β-CD) and its derivatives including hydroxypropyl-β-cyclodextrin (HP-β-CD), sulfobutylether-β-cyclodextrin (SBE-β-CD) in basic aqueous solution. The supramolecular system was investigated by the methods of fluorescence, UV-vis absorption spectroscopy, nuclear magnetic resonance (NMR) technique. The inclusion ability of cyclodextrins exhibited remarkable difference for β-CD, HP-β-CD and SBE-β-CD. Association constants as high as K=1.1×10 4 M -1 in the case of HP-β-CD/TEPyP and 2.0×10 5 M -1 in the case of SBE-β-CD/TEPyP complexes were determined, whereas a lower value ( K=550 M -1) was given in the case of β-CD/TEPyP. The results showed that hydrogen bonding and charge attraction play important roles in the processes of host-guest interaction. The interaction mechanism of inclusion processes could be explained by the analysis of NMR spectroscopy. The supramolecular assembly was formed. β-CD and HP-β-CD approached from the primary face of cavities of CDs.

  15. Comparative study on the inclusion behavior between meso-tetrakis(4-N-ethylpyridiniurmyl)porphyrin and beta-cyclodextrin derivatives.

    PubMed

    Xiliang, Guo; Shaomin, Shuang; Chuan, Dong; Feng, Feng; Wong, M S

    2005-01-14

    5,10,15,20-Tetrakis(4-N-ethylpyridiniurmyl)porphyrin (TEPyP) formed 1:1 stoichiometry inclusion complexes with beta-cyclodextrin (beta-CD) and its derivatives including hydroxypropyl-beta-cyclodextrin (HP-beta-CD), sulfobutylether-beta-cyclodextrin (SBE-beta-CD) in basic aqueous solution. The supramolecular system was investigated by the methods of fluorescence, UV-vis absorption spectroscopy, nuclear magnetic resonance (NMR) technique. The inclusion ability of cyclodextrins exhibited remarkable difference for beta-CD, HP-beta-CD and SBE-beta-CD. Association constants as high as K=1.1 x 10(4) M(-1) in the case of HP-beta-CD/TEPyP and 2.0 x 10(5) M(-1) in the case of SBE-beta-CD/TEPyP complexes were determined, whereas a lower value (K=550 M(-1)) was given in the case of beta-CD/TEPyP. The results showed that hydrogen bonding and charge attraction play important roles in the processes of host-guest interaction. The interaction mechanism of inclusion processes could be explained by the analysis of NMR spectroscopy. The supramolecular assembly was formed. beta-CD and HP-beta-CD approached from the primary face of cavities of CDs.

  16. A "high 4He/3He" mantle material detected under the East Pacific Rise (15°4'N)

    NASA Astrophysics Data System (ADS)

    Mougel, Berengere; Moreira, Manuel; Agranier, Arnaud

    2015-03-01

    We investigate in details helium isotope data reported in Mougel et al. (2014) for 14 basaltic samples collected on the East Pacific Rise by submersible (15°4'N) where the ridge interacts with the Mathematician seamounts. Samples locations are separated by only few hundred meters across a 15 km along-axis profile. The data reveal a strong geochemical variability that has never been observed at such high spatial resolution for helium isotope compositions. Moreover, they reveal an unusually high 4He/3He mantle component also characterized by unradiogenic lead, atypical in oceanic basalts. He-Pb systematics suggests a mixture between a nonradiogenic lead and radiogenic helium pyroxenitic component, recycled from the deep continental lithosphere and the ambient peridotitic mantle. The He isotope difference between these two end-members can be interpreted as a time evolution of two distinct mantle sources after a slight (U + Th)/3He fractionation, likely due to some ancient degassing during the formation of deep continental pyroxenites.

  17. Photodynamic Therapy of the Murine LM3 Tumor Using Meso-Tetra (4-N,N,N-Trimethylanilinium) Porphine

    PubMed Central

    Colombo, L. L.; Juarranz, A.; Cañete, M.; Villanueva, A.; Stockert, J. C.

    2007-01-01

    Photodynamic therapy (PDT) of cancer is based on the cytotoxicity induced by a photosensitizer in the presence of oxygen and visible light, resulting in cell death and tumor regression. This work describes the response of the murine LM3 tumor to PDT using meso-tetra (4-N,N,N-trimethylanilinium) porphine (TMAP). BALB/c mice with intradermal LM3 tumors were subjected to intravenous injection of TMAP (4 mg/kg) followed 24 h later by blue-red light irradiation (λmax: 419, 457, 650 nm) for 60 min (total dose: 290 J/cm2) on depilated and glycerol-covered skin over the tumor of anesthetized animals. Control (drug alone, light alone) and PDT treatments (drug + light) were performed once and repeated 48 h later. No significant differences were found between untreated tumors and tumors only treated with TMAP or light. PDT-treated tumors showed almost total but transitory tumor regression (from 3 mm to less than 1 mm) in 8/9 animals, whereas no regression was found in 1/9. PDT response was heterogeneous and each tumor showed different regression and growth delay. The survival of PDT-treated animals was significantly higher than that of TMAP and light controls, showing a lower number of lung metastasis but increased tumor-draining lymph node metastasis. Repeated treatment and reduction of tissue light scattering by glycerol could be useful approaches in studies on PDT of cancer. PMID:23675051

  18. Competitive sorption between 17alpha-ethinyl estradiol and bisphenol A/4-n-nonylphenol by soils.

    PubMed

    Li, Jianzhong; Jiang, Lu; Xiang, Xi; Xu, Shuang; Wen, Rou; Liu, Xiang

    2013-06-01

    The sorption of 17alpha-ethinyl estradiol (EE2), bisphenol A (BPA), and 4-n-nonylphenol (NP) in single systems and the sorption of EE2 with different initial aqueous concentrations of BPA or NP were examined using three soils. Results showed that all sorption isotherms were nonlinear and fit the Freundlich model. The degree of nonlinearity was in the order BPA (0.537-0.686) > EE2 (0.705-0.858) > NP (0.875-0.0.951) in single systems. The isotherm linearity index of EE2 sorption calculated by the Freundlich model for Loam, Silt Loam and Silt increased from 0.758, 0.705 and 0.858, to 0.889, 0.910 and 0.969, respectively, when BPA concentration increased from 0 to 1000 microg/L, but the effect of NP was comparably minimal. Additionally, EE2 significantly suppressed the sorption of BPA, but insignificantly suppressed that of NP. These findings can be attributed to the difference of sorption affinity of EE2, NP and BPA on the hard carbon (e.g., black carbon) of soil organic matter that dominated the sorption in the low equilibrium aqueous concentration range of endocrine-disrupting chemicals (EDCs). Competitive sorption among EDCs presents new challenges for predicting the transport and fate of EDCs under the influence of co-solutes.

  19. Transition metal complexes of Vanillin- 4N-(2-pyridyl) thiosemicarbazone (H 2VPT); thermal, structural and spectroscopic studies

    NASA Astrophysics Data System (ADS)

    El-Reash, Gaber Abu; El-Ayaan, Usama; Gabr, I. M.; El-Rachawy, El-Bastawesy

    2010-04-01

    The present work carried out a study on the ligational behavior of the new ligand, Vanillin- 4N-(2-pyridyl) thiosemicarbazone (H 2VPT) 1 towards some transition metal ions namely, Mn 2+, Co 2+, Ni 2+, Cu 2+, Zn 2+,Cd 2+, Hg 2+ and U 6+. These complexes namely [Mn(HVPT)Cl] 2, [Co(VPT)(H 2O)] 2H 2O 3, [Ni(HVPT)Cl(H 2O)] 4, [Cu(HVPT)Cl(H 2O)] 5, [Zn(VPT)(H 2O)]H 2O 6, [Cd(HVPT)Cl(H 2O)] 7, [Hg(VPT)(H 2O)]H 2O 8 and [UO 2(H 2VPT)(OAc) 2]H 2O 9, were characterized by elemental analysis, spectral (IR, 1H NMR and UV-vis) and magnetic moment measurements. The suggested structures were confirmed by applying geometry optimization and conformational analysis. Thermal properties and decomposition kinetics of all compounds are investigated. The interpretation, mathematical analysis and evaluation of kinetic parameters ( E, A, Δ H, Δ S and Δ G) of all thermal decomposition stages have been evaluated using Coats-Redfern equation. ESR spectra of [Cu(HVPT)Cl]H 2O at room temperature show broad signal, indicating spin-exchange interactions between copper(II) ions.

  20. Nuclear Magnetic Resonance Measurements and Electronic Structure of Pu(IV) in [(Me)4N]2PuCl6.

    PubMed

    Mounce, Andrew M; Yasuoka, Hiroshi; Koutroulakis, Georgios; Lee, Jeongseop A; Cho, Herman; Gendron, Frédéric; Zurek, Eva; Scott, Brian L; Trujillo, Julie A; Slemmons, Alice K; Cross, Justin N; Thompson, Joe D; Kozimor, Stosh A; Bauer, Eric D; Autschbach, Jochen; Clark, David L

    2016-09-01

    The synthesis, electronic structure, and characterization via single-crystal X-ray diffraction, nuclear magnetic resonance (NMR) spectroscopy, and magnetic susceptibility of (Me4N)2PuCl6 are reported. NMR measurements were performed to both search for the direct (239)Pu resonance and to obtain local magnetic and electronic information at the Cl site through (35)Cl and (37)Cl spectra. No signature of (239)Pu NMR was observed. The temperature dependence of the Cl spectra was simulated by diagonalizing the Zeeman and quadrupolar Hamiltonians for (35)Cl, (37)Cl, and (14)N isotopes. Electronic structure calculations predict a magnetic Γ5 triplet ground state of Pu(IV) in the crystalline electric field of the undistorted PuCl6 octahedron. A tetragonal distortion would result in a very small splitting (∼20 cm(-1)) of the triplet ground state into a nonmagnetic singlet and a doublet state. The Cl shifts have an inflection point at T ≈ 15 K, differing from the bulk susceptibility, indicating a nonmagnetic crystal field ground state. The Cl spin-lattice relaxation time is constant to T = 15 K, below which it rapidly increases, also supporting the nonmagnetic crystal field ground state.

  1. General transformation of α cluster model wave function to jj-coupling shell model in various 4N nuclei

    NASA Astrophysics Data System (ADS)

    Itagaki, N.; Matsuno, H.; Suhara, T.

    2016-09-01

    The antisymmetrized quasi-cluster model (AQCM) is a method to describe transitions from the α cluster wave functions to jj-coupling shell model wave functions. In this model, the cluster-shell transition is characterized by only two parameters: R representing the distance between α clusters and Λ describing the breaking of α clusters. The contribution of the spin-orbit interaction, very important in the jj-coupling shell model, can be taken into account starting with the α cluster model wave function. In this article we show the generality of AQCM by extending the application to heavier regions: various 4N nuclei from 4He to 100Sn. The characteristic magic numbers of the jj-coupling shell model, 28 and 50, are described starting with the α cluster model. The competition of two different configurations is discussed in 20Ne (16O + one quasi-cluster and 12C + two quasi-clusters) and 28Si (pentagon shape of five quasi-clusters and 12C + 16O). Also, we compare the energy curves for the α + 40Ca cluster configuration calculated with and without the α breaking effect in 44Ti.

  2. Distortion-sensitive insight into the pretransitional behavior of 4-n-octyloxy-4‧-cyanobiphenyl (8OCB)

    NASA Astrophysics Data System (ADS)

    Rzoska, Sylwester J.; Drozd-Rzoska, Aleksandra; Mukherjee, Prabir K.; Lopez, David O.; Martinez-Garcia, Julio C.

    2013-06-01

    Results of studies of the static and dynamic dielectric properties in rod-like 4-n-octyloxy-4‧-cyanobiphenyl (8OCB) with isotropic (I)-nematic (N)-smectic A (SmA)-crystal (Cr) mesomorphism, combined with measurements of the low-frequency nonlinear dielectric effect and heat capacity are presented. The analysis is supported by the derivative-based and distortion-sensitive transformation of experimental data. Evidence for the I-N and N-SmA pretransitional anomalies, indicating the influence of tricritical behavior, is shown. It has also been found that neither the N phase nor the SmA phase are uniform and hallmarks of fluid-fluid crossovers can be detected. The dynamics, tested via the evolution of the primary relaxation time, is clearly non-Arrhenius and described via τ(T) = τc(T-TC)-ϕ. In the immediate vicinity of the I-N transition a novel anomaly has been found: Δτ ∝ 1/(T - T*), where T* is the temperature of the virtual continuous transition and Δτ is the excess over the ‘background behavior’. Experimental results are confronted with the comprehensive Landau-de Gennes theory based modeling.

  3. OPTICAL SPECTROPHOTOMETRIC MONITORING OF THE EXTREME LUMINOUS BLUE VARIABLE STAR GR 290 (ROMANO's STAR) IN M 33

    SciTech Connect

    Polcaro, V. F.; Viotti, R. F.; Rossi, C.; Galleti, S.; Gualandi, R.; Norci, L.

    2011-01-15

    We study the long-term, S Dor-type variability and the present hot phase of the luminous blue variable (LBV) star GR 290 (Romano's Star) in M 33 in order to investigate possible links between the LBV and the late, nitrogen sequence Wolf-Rayet Stars (WNL) stages of very massive stars. We use intermediate-resolution spectra, obtained with the William Herschel Telescope (WHT) in 2008 December, when GR 290 was at minimum (V = {approx}18.6), as well as new low-resolution spectra and BVRI photometry obtained with the Loiano and Cima Ekar telescopes during 2007-2010. We identify more than 80 emission lines in the 3100-10000 A range covered by the WHT spectra, belonging to different species: the hydrogen Balmer and Paschen series, neutral and ionized helium, C III, N II-III, S IV, Si III-IV, and many forbidden lines of [N II], [O III], [S III], [A III], [Ne III], and [Fe III]. Many lines, especially the He I triplets, show a P Cygni profile with an a-e radial velocity difference of -300 to -500 km s{sup -1}. The shape of the 4630-4713 A emission blend and of other emission lines resembles that of WN9 stars; the blend deconvolution shows that the He II 4686 A has a strong broad component with FWHM {approx_equal} 1700 km s{sup -1}. During 2003-2010 the star underwent large spectral variations, best seen in the 4630-4686 A emission feature. Using the late-WN spectral types of Crowther and Smith, GR 290 apparently varied between the WN11 and WN8-9 spectral types; the hotter the star was the fainter its visual magnitude was. This spectrum-visual luminosity anticorrelation of GR 290 is reminiscent of the behavior of the best-studied LBVs, such as S Dor and AG Car. During the 2008 minimum, we found a significant decrease in bolometric luminosity, which could be attributed to absorption by newly formed circumstellar matter. We suggest that the broad 4686 A line and the optical continuum formed in a central Wolf-Rayet region, while the narrow emission line spectrum originated in an

  4. Responses of biofilm characteristics to variations in temperature and NH4(+)-N loading in a moving-bed biofilm reactor treating micro-polluted raw water.

    PubMed

    Zhang, Shuangfu; Wang, Yayi; He, Weitao; Wu, Min; Xing, Meiyan; Yang, Jian; Gao, Naiyun; Yin, Daqiang

    2013-03-01

    A pilot-scale moving-bed biofilm reactor (MBBR) for biological treatment of micro-polluted raw water was operated over 400days to investigate the responses of biofilm characteristics and nitrification performance to variations in temperature and NH4(+)-N loading. The mean removal efficiency of NH4(+)-N in the MBBR reached 71.4±26.9%, and batch experiments were performed to study nitrification kinetics for better process understanding. Seven physical-chemical parameters, including volatile solids (VS), polysaccharides (PS) and phospholipids (PL) increased firstly, and then rapidly decreased with increasing temperature and NH4(+)-N loading, and properly characterized the attached biomass during biofilm development and detachment in the MBBR. The biofilm compositions were described by six ratios, e.g., PS/VS and PL/VS ratios showed different variation trends, indicating different responses of PS and PL to the changes in temperature and NH4(+)-N loading. Furthermore, fluorescent in situ hybridization (FISH) analysis revealed that increased NH4(+)-N loadings caused an enrichment of the nitrifying biofilm.

  5. Teleseismic P-wave polarization analysis at the Gräfenberg array

    NASA Astrophysics Data System (ADS)

    Cristiano, L.; Meier, T.; Krüger, F.; Keers, H.; Weidle, C.

    2016-09-01

    P-wave polarization at the Gräfenberg array (GRF) in southern Germany is analyzed in terms of azimuthal deviations and deviations in the vertical polarization using 20 years of broad band recordings. An automated procedure for estimating P-wave polarization parameters is suggested, based on the definition of a characteristic function, which evaluates the polarization angles and their time variability as well as the amplitude, linearity and the signal-to-noise ratio of the P-wave. P-wave polarization at the GRF array is shown to depend mainly on frequency and backazimuth and only slightly on epicentral distance indicating depth dependent local anisotropy and lateral heterogeneity. A harmonic analysis is applied to the azimuthal anomalies to analyze their periodicity as a function of backazimuth. The dominant periods are 180° and 360°. At low frequencies, between 0.03-0.1 Hz, the observed fast directions of azimuthal anisotropy inferred from the 180° periodicity are similar across the array. The average fast direction of azimuthal anisotropy at these frequencies is N20°E with an uncertainty of about 8° and is consistent with fast directions of Pn-wave propagation. Lateral velocity gradients determined for the low frequency band are compatible with the Moho topography of the area. A more complex pattern in the horizontal fast axis orientation beneath the GRF array is observed in the high frequency band between 0.1-0.5 Hz, and is attributed to anisotropy in the upper crust. A remarkable rotation of the horizontal fast axis orientation across the suture between the geological units Moldanubicum and Saxothuringicum is observed. In contrast, the 360° periodicity at high frequencies is rather consistent across the array and may either point to lower velocities in the upper crust towards the Bohemian Massif and/or to anisotropy dipping predominantly in the NE-SW direction. Altogether, P-wave polarization analysis indicates the presence of layered lithospheric

  6. The Richardson constant and barrier inhomogeneity at Au/Si3N4/n-Si (MIS) Schottky diodes

    NASA Astrophysics Data System (ADS)

    Tataroğlu, A.; Pür, F. Z.

    2013-07-01

    Si3N4 films were deposited on n-type silicon substrate by the radio frequency magnetron sputtering technique. The current-voltage (I-V) characteristics of Au/Si3N4/n-Si (metal-insulator-semiconductor) Schottky diodes were investigated in the temperature range of 160-400 K. Experimental results show an abnormal increase in the zero-bias barrier height (BH) (ΦBo) and a decrease in the ideality factor (n) with increasing temperature. This behavior is attributed to barrier inhomogeneities by assuming a Gaussian distribution (GD) of BHs. The conventional Richardson plot (ln(Io/T2) versus 1000/T) exhibits a linearity above about 300 K. The values of activation energy (Ea) and Richardson constant (A*) were found to be 0.350 eV and 1.242 × 10-3 A cm-2 K-2 from the slope and the intercept at the ordinate of the linear region of this plot, respectively. Also, we attempted to draw a ΦBo versus q/2kT plot to determine evidence of the GD of BHs, and the values of \\bar \\Phi _{{\\rm{Bo}}} = 0.999\\,{\\rm{eV}} and σs = 0.137 eV for the mean BH and zero-bias standard deviation, respectively, were obtained from this plot; then, a modified ln(Io/T2) - q2σs2/2k2T2 versus q/kT plot gives \\bar \\Phi _{{\\rm{Bo}}} and A* as 0.992 eV and 108.228 A cm-2 K-2, respectively. This value of A* is very close to the theoretical value of 112 A cm-2 K-2 for n-type Si.

  7. Capacitance and conductance characterization of nano-ZnGa{sub 2}Te{sub 4}/n-Si diode

    SciTech Connect

    Fouad, S.S.; Sakr, G.B.; Yahia, I.S.; Abdel-Basset, D.M.; Yakuphanoglu, F.

    2014-01-01

    Graphical abstract: - Highlights: • XRD and DTA micrographs were used to study the structure of ZnGa{sub 2}Te{sub 4}. • C–V, G–V and R{sub s}–V of the diode characteristics have been analyzed for the first time. • Dielectric constant, dielectric loss, loss tangent and ac conductivity were determined. • The interfaces states were determined using conductance–voltage technique. • ZnGa{sub 2}Te{sub 4} is a good candidate for electronic device applications. - Abstract: Capacitance–voltage (C–V) and conductance–voltage (G–V) characteristics of p-ZnGa{sub 2}Te{sub 4}/n-Si HJD were studied over a wide frequency and temperature. Both the interface states density N{sub ss} and series resistance R{sub s} were strongly frequency and temperature dependent. The interface states density N{sub ss} is decreased with increasing frequency and increase with increasing temperature. The values of the built-in potential (V{sub bi}) were calculated and found to increase with increasing temperature and frequency. The values of capacitance C, conductance G, series resistance R{sub s}, corrected capacitance C{sub ADJ}, corrected conductance G{sub ADJ}, dielectric constant (ε′), dielectric loss (ε″), loss tangent (tan δ) and the AC conductivity (σ{sub ac}) are strongly dependent on the applied frequency, voltage and temperature. The obtained results show that the locations of N{sub ss} and R{sub s} have a significant effect on the electrical characteristics of the studied diode.

  8. Solvent sensitive intramolecular charge transfer dynamics in the excited states of 4-N,N-dimethylamino-4'-nitrobiphenyl.

    PubMed

    Ghosh, Rajib; Nandi, Amitabha; Palit, Dipak K

    2016-03-21

    Organic molecules substituted with the nitro group show efficient nonlinear optical (NLO) properties, which are a consequence of the strong intramolecular charge transfer (ICT) character of the molecules because of the strong electron withdrawing nature of the nitro group and rapid responsiveness because of highly movable π-electrons. Dynamics of the ICT process in the excited states of a push-pull biphenyl derivative, namely, 4-N,N-dimethylamino-4'-nitrobiphenyl (DNBP), an efficient NLO material, has been investigated using ultrafast transient absorption spectroscopy. The experimental results have been corroborated with DFT and TDDFT calculations. In solvents of large polarity, e.g. acetonitrile, the ultrafast ICT process of DNBP is associated with the barrierless twisting of the N,N-dimethylaniline (DMA) group with respect to the nitrobenzene moiety to populate the twisted ICT (or TICT) state, and the rate of this process is solely governed by the viscosity of the medium. In solvents of moderate polarity, e.g. ethyl acetate, the rate of the twisting process is significantly slowed down and the LE and TICT states remain in equilibrium because of a low energy barrier for interconversion between these two states. By further lowering the polarity of the solvent, e.g. in dioxane, the twisting process is completely retarded. In nonpolar solvents, e.g. cyclohexane, a reverse twisting motion towards the planar geometry (i.e. the PICT process) has been evident in the excited state dynamics. In this solvent, the S1 state undergoes an ultrafast intersystem crossing to the triplet state because of its close proximity with the T2 state. PMID:26907751

  9. Magnetic properties of nanocrystalline ε-Fe{sub 3}N and Co{sub 4}N phases synthesized by newer precursor route

    SciTech Connect

    Theerthagiri, J.; Dalavi, Shankar B.; Manivel Raja, M.; Panda, R.N.

    2013-11-15

    Graphical abstract: Nanocrystalline ε-Fe{sub 3}N and Co{sub 4}N nitride phases are synthesized first time by newer chemical routes. The ε-Fe{sub 3}N phase crystallizes in hexagonal structure with unit cell parameters, a = 4.76 Å and c = 4.41 Å. The Co{sub 4}N phase crystallizes in face centred cubic (fcc) structure with unit cell parameters, a = 3.55 Å. The estimated crystallite size for ε-Fe{sub 3}N and Co{sub 4}N phases are 29 nm and 22 nm, respectively. The values of saturation magnetization for ε-Fe{sub 3}N and Co{sub 4}N phases are found to be 28.1 emu/g and 123.6 emu/g respectively. The reduction of magnetic moments in ultrafine materials compared to bulk materials has been explained by fine particle size and surface effects. We have synthesized the high moment ε-Fe{sub 3}N and Co{sub 4}N nitride with reduced coercivity which may find applications as soft magnetic materials. - Highlights: • Nanocrystalline ε-Fe{sub 3}N and Co{sub 4}N nitride phases are synthesized. • The ε-Fe{sub 3}N and Co{sub 4}N crystallizes in hexagonal and fcc structure respectively. • The observed magnetic parameters indicate soft magnetic properties. • The magnetic properties have been explained on the basis of fine particle magnetism. - Abstract: Nanocrystalline ε-Fe{sub 3}N and Co{sub 4}N nitride phases are synthesized first time by using tris(1,2-diaminoethane)iron(II) chloride and tris(1,2-diaminoethane)cobalt(III) chloride precursors, respectively. To prepare ε-Fe{sub 3}N and Co{sub 4}N nitride phases, the synthesized precursors were mixed with urea in 1:12 ratio and heat treated at various temperatures in the range of 450–900 °C under the ultrapure nitrogen gas atmosphere. The precursors are confirmed by FT-IR study. The ε-Fe{sub 3}N phase crystallizes in hexagonal structure with unit cell parameters, a = 4.76 Å and c = 4.41 Å. The Co{sub 4}N phase crystallizes in face centred cubic (fcc) structure with unit cell parameters, a = 3.55 Å. The

  10. Enhanced inverse spin-Hall voltage in (001) oriented Fe4N/Pt polycrystalline films without contribution of planar-Hall effect

    NASA Astrophysics Data System (ADS)

    Isogami, Shinji; Tsunoda, Masakiyo

    2016-04-01

    In this study, the output DC electric voltage (V out) generated by a Pt-capped Fe4N bilayer film (Fe4N/Pt) under ferromagnetic resonance conditions at room temperature was assessed. The contributions from the inverse spin-Hall effect (ISHE), the planar-Hall effect (PHE) and the anomalous-Hall effect (AHE) were separated from the output voltage by analysis of V out values determined at varying external field polar angles. The results showed that the polarity of the ISHE (V ISHE) component of V out was opposite to that of the PHE (V PHE). As a result, the magnitude of the intrinsic V ISHE was beyond V out by as much as the magnitude of V PHE. The X-ray diffraction structural analysis revealed the polycrystal of the Fe4N/Pt with (001) orientation, which might be one of the possible mechanisms for enhanced intrinsic V ISHE.

  11. Breed-Dependent Transcriptional Regulation of 5′-Untranslated GR (NR3C1) Exon 1 mRNA Variants in the Liver of Newborn Piglets

    PubMed Central

    Yang, Xiaojing; Ni, Yingdong; Cong, Rihua; Soloway, Paul D.; Zhao, Ruqian

    2012-01-01

    Glucocorticoids are vital for life and regulate an array of physiological functions by binding to the ubiquitously expressed glucocorticoid receptor (GR, also known as NR3C1). Previous studies demonstrate striking breed differences in plasma cortisol levels in pigs. However, investigation into the breed-dependent GR transcriptional regulation is hampered by lacking porcine GR promoter information. In this study, we sequenced 5.3 kb upstream of the translation start codon of the porcine GR gene, and identified seven alternative 5′-untranslated exons 1–4, 1–5, 1–6, 1–7, 1–8, 1–9,10 and 1–11. Among all these mRNA variants, exons 1–4 and 1–5, as well as the total GR were expressed significantly (P<0.05) higher in the liver of newborn piglets of Large White (LW) compared with Erhualian, a Chinese indigenous breed. Overall level of CpG methylation in the region flanking exons 1–4 and 1–5 did not show breed difference. However, nuclear content of Sp1, p-CREB and GR in the liver was significantly (P<0.05) higher in LW piglets, associated with enhanced binding of p-CREB, and higher level of histone H3 acetylation in 1–4 and 1–5 promoters. In contrast, GR binding to promoters of exons 1–4 and 1–5 was significantly diminished in LW piglets, implicating the presence of negative GREs. These results indicate that the difference in the hepatic expression of GR transcript variants between two breeds of pigs is determined, at least partly, by the disparity in the binding of transcription factors and the enrichment of histone H3 acetylation to the promoters. PMID:22792317

  12. Breed-dependent transcriptional regulation of 5'-untranslated GR (NR3C1) exon 1 mRNA variants in the liver of newborn piglets.

    PubMed

    Zou, Huafeng; Li, Runsheng; Jia, Yimin; Yang, Xiaojing; Ni, Yingdong; Cong, Rihua; Soloway, Paul D; Zhao, Ruqian

    2012-01-01

    Glucocorticoids are vital for life and regulate an array of physiological functions by binding to the ubiquitously expressed glucocorticoid receptor (GR, also known as NR3C1). Previous studies demonstrate striking breed differences in plasma cortisol levels in pigs. However, investigation into the breed-dependent GR transcriptional regulation is hampered by lacking porcine GR promoter information. In this study, we sequenced 5.3 kb upstream of the translation start codon of the porcine GR gene, and identified seven alternative 5'-untranslated exons 1-4, 1-5, 1-6, 1-7, 1-8, 1-9,10 and 1-11. Among all these mRNA variants, exons 1-4 and 1-5, as well as the total GR were expressed significantly (P<0.05) higher in the liver of newborn piglets of Large White (LW) compared with Erhualian, a Chinese indigenous breed. Overall level of CpG methylation in the region flanking exons 1-4 and 1-5 did not show breed difference. However, nuclear content of Sp1, p-CREB and GR in the liver was significantly (P<0.05) higher in LW piglets, associated with enhanced binding of p-CREB, and higher level of histone H3 acetylation in 1-4 and 1-5 promoters. In contrast, GR binding to promoters of exons 1-4 and 1-5 was significantly diminished in LW piglets, implicating the presence of negative GREs. These results indicate that the difference in the hepatic expression of GR transcript variants between two breeds of pigs is determined, at least partly, by the disparity in the binding of transcription factors and the enrichment of histone H3 acetylation to the promoters.

  13. The broad-spectrum anti-emetic activity of the novel non-peptide tachykinin NK1 receptor antagonist GR203040.

    PubMed Central

    Gardner, C. J.; Twissell, D. J.; Dale, T. J.; Gale, J. D.; Jordan, C. C.; Kilpatrick, G. J.; Bountra, C.; Ward, P.

    1995-01-01

    1. Following our earlier observations that the tachykinin NK1 receptor antagonist CP-99,994 is an effective anti-emetic in ferrets, we have examined the anti-emetic effects of a more potent and novel NK1 receptor antagonist, GR203040, against various emetic stimuli in the ferret, dog and house musk shrew (Suncus murinus). 2. In ferrets, GR203040 (0.1 mg kg-1 s.c. or i.v.) is effective against emesis induced by radiation, cisplatin, cyclophosphamide, copper sulphate, ipecacuanha or morphine. 3. In animals in which emesis had been established with cisplatin, GR203040 (1 mg kg-1 s.c.) was fully effective as an interventional treatment. No further emesis was seen in animals treated with GR203040 whilst saline-treated animals continued to vomit. 4. GR203040 (0.1 mg kg-1 s.c.) retains anti-emetic efficacy in the ferret, even when given as a 6 h pretreatment, indicating that this compound has a long duration of action. The compound is also effective orally at the same dose, when given as a 90 min pretreatment. 5. GR203040 (0.1 mg kg-1 i.v.) is fully effective against ipecacuanha-induced emesis in the dog. 6. GR203040 is effective against motion- and cisplatin-induced emesis in Suncus murinus. These effects were seen at doses an order of magnitude greater than those shown to be effective against cisplatin in the ferret. 7. In conclusion, GR203040 is a novel anti-emetic agent, and the broad spectrum of anti-emetic activity, together with activity observed in three species, suggests that this compound is worthy of clinical investigation. Images Figure 2 Figure 4 PMID:8719790

  14. Structural characterisation of human galectin-4 N-terminal carbohydrate recognition domain in complex with glycerol, lactose, 3′-sulfo-lactose, and 2′-fucosyllactose

    PubMed Central

    Bum-Erdene, Khuchtumur; Leffler, Hakon; Nilsson, Ulf J.; Blanchard, Helen

    2016-01-01

    Galectin-4 is a tandem-repeat galectin with two distinct carbohydrate recognition domains (CRD). Galectin-4 is expressed mainly in the alimentary tract and is proposed to function as a lipid raft and adherens junction stabilizer by its glycan cross-linking capacity. Galectin-4 plays divergent roles in cancer and inflammatory conditions, either promoting or inhibiting each disease progression, depending on the specific pathological condition. The study of galectin-4’s ligand-binding profile may help decipher its roles under specific conditions. Here we present the X-ray structures of human galectin-4 N-terminal CRD (galectin-4N) bound to different saccharide ligands. Galectin-4’s overall fold and its core interactions to lactose are similar to other galectin CRDs. Galectin-4N recognises the sulfate cap of 3′-sulfated glycans by a weak interaction through Arg45 and two water-mediated hydrogen bonds via Trp84 and Asn49. When galectin-4N interacts with the H-antigen mimic, 2′-fucosyllactose, an interaction is formed between the ring oxygen of fucose and Arg45. The extended binding site of galectin-4N may not be well suited to the A/B-antigen determinants, α-GalNAc/α-Gal, specifically due to clashes with residue Phe47. Overall, galectin-4N favours sulfated glycans whilst galectin-4C prefers blood group determinants. However, the two CRDs of galectin-4 can, to a less extent, recognise each other’s ligands. PMID:26828567

  15. GR3027 antagonizes GABAA receptor-potentiating neurosteroids and restores spatial learning and motor coordination in rats with chronic hyperammonemia and hepatic encephalopathy.

    PubMed

    Johansson, Maja; Agusti, Ana; Llansola, Marta; Montoliu, Carmina; Strömberg, Jessica; Malinina, Evgenya; Ragagnin, Gianna; Doverskog, Magnus; Bäckström, Torbjörn; Felipo, Vicente

    2015-09-01

    Hepatic encephalopathy (HE) is one of the primary complications of liver cirrhosis. Current treatments for HE, mainly directed to reduction of ammonia levels, are not effective enough because they cannot completely eliminate hyperammonemia and inflammation, which induce the neurological alterations. Studies in animal models show that overactivation of GABAA receptors is involved in cognitive and motor impairment in HE and that reducing this activation restores these functions. We have developed a new compound, GR3027, that selectively antagonizes the enhanced activation of GABAA receptors by neurosteroids such as allopregnanolone and 3α,21-dihydroxy-5α-pregnan-20-one (THDOC). This work aimed to assess whether GR3027 improves motor incoordination, spatial learning, and circadian rhythms of activity in rats with HE. GR3027 was administered subcutaneously to two main models of HE: rats with chronic hyperammonemia due to ammonia feeding and rats with portacaval shunts (PCS). Motor coordination was assessed in beam walking and spatial learning and memory in the Morris water maze and the radial maze. Circadian rhythms of ambulatory and vertical activity were also assessed. In both hyperammonemic and PCS rats, GR3027 restores motor coordination, spatial memory in the Morris water maze, and spatial learning in the radial maze. GR3027 also partially restores circadian rhythms of ambulatory and vertical activity in PCS rats. GR3027 is a novel approach to treatment of HE that would normalize neurological functions altered because of enhanced GABAergic tone, affording more complete normalization of cognitive and motor function than current treatments for HE.

  16. GR3027 antagonizes GABAA receptor-potentiating neurosteroids and restores spatial learning and motor coordination in rats with chronic hyperammonemia and hepatic encephalopathy

    PubMed Central

    Johansson, Maja; Agusti, Ana; Llansola, Marta; Montoliu, Carmina; Strömberg, Jessica; Malinina, Evgenya; Ragagnin, Gianna; Doverskog, Magnus; Bäckström, Torbjörn

    2015-01-01

    Hepatic encephalopathy (HE) is one of the primary complications of liver cirrhosis. Current treatments for HE, mainly directed to reduction of ammonia levels, are not effective enough because they cannot completely eliminate hyperammonemia and inflammation, which induce the neurological alterations. Studies in animal models show that overactivation of GABAA receptors is involved in cognitive and motor impairment in HE and that reducing this activation restores these functions. We have developed a new compound, GR3027, that selectively antagonizes the enhanced activation of GABAA receptors by neurosteroids such as allopregnanolone and 3α,21-dihydroxy-5α-pregnan-20-one (THDOC). This work aimed to assess whether GR3027 improves motor incoordination, spatial learning, and circadian rhythms of activity in rats with HE. GR3027 was administered subcutaneously to two main models of HE: rats with chronic hyperammonemia due to ammonia feeding and rats with portacaval shunts (PCS). Motor coordination was assessed in beam walking and spatial learning and memory in the Morris water maze and the radial maze. Circadian rhythms of ambulatory and vertical activity were also assessed. In both hyperammonemic and PCS rats, GR3027 restores motor coordination, spatial memory in the Morris water maze, and spatial learning in the radial maze. GR3027 also partially restores circadian rhythms of ambulatory and vertical activity in PCS rats. GR3027 is a novel approach to treatment of HE that would normalize neurological functions altered because of enhanced GABAergic tone, affording more complete normalization of cognitive and motor function than current treatments for HE. PMID:26138462

  17. GR3027 antagonizes GABAA receptor-potentiating neurosteroids and restores spatial learning and motor coordination in rats with chronic hyperammonemia and hepatic encephalopathy.

    PubMed

    Johansson, Maja; Agusti, Ana; Llansola, Marta; Montoliu, Carmina; Strömberg, Jessica; Malinina, Evgenya; Ragagnin, Gianna; Doverskog, Magnus; Bäckström, Torbjörn; Felipo, Vicente

    2015-09-01

    Hepatic encephalopathy (HE) is one of the primary complications of liver cirrhosis. Current treatments for HE, mainly directed to reduction of ammonia levels, are not effective enough because they cannot completely eliminate hyperammonemia and inflammation, which induce the neurological alterations. Studies in animal models show that overactivation of GABAA receptors is involved in cognitive and motor impairment in HE and that reducing this activation restores these functions. We have developed a new compound, GR3027, that selectively antagonizes the enhanced activation of GABAA receptors by neurosteroids such as allopregnanolone and 3α,21-dihydroxy-5α-pregnan-20-one (THDOC). This work aimed to assess whether GR3027 improves motor incoordination, spatial learning, and circadian rhythms of activity in rats with HE. GR3027 was administered subcutaneously to two main models of HE: rats with chronic hyperammonemia due to ammonia feeding and rats with portacaval shunts (PCS). Motor coordination was assessed in beam walking and spatial learning and memory in the Morris water maze and the radial maze. Circadian rhythms of ambulatory and vertical activity were also assessed. In both hyperammonemic and PCS rats, GR3027 restores motor coordination, spatial memory in the Morris water maze, and spatial learning in the radial maze. GR3027 also partially restores circadian rhythms of ambulatory and vertical activity in PCS rats. GR3027 is a novel approach to treatment of HE that would normalize neurological functions altered because of enhanced GABAergic tone, affording more complete normalization of cognitive and motor function than current treatments for HE. PMID:26138462

  18. On the mechanism of photochromism of 4'-N,N-dimethylamino-7-hydroxyflavylium in pluronic F127.

    PubMed

    Gomes, Raquel; Laia, César A T; Pina, Fernando

    2009-08-13

    The photochromism of the compound 4'-N,N-dimethylamino-7-hydroxyflavylium incorporated in Pluronic F127 micelles and gels was studied in great detail. The red flavylium ion (AH(+)) or the quinoidal base (A), depending on pH, are the irradiation products of the colorless trans-chalcone (Ct). Absorption and fluorescence (steady-state, time-resolved, and anisotropy), pH jumps, and flash photolysis were used to characterize the system. At moderately acidic to neutral pH values, the Ct species is distributed between the core and corona of the Pluronic micelle, as well as in the aqueous phase. At acidic pH values, AH(+) remains most probably in the water phase. The Ct maximum absorption wavelength constitutes a good sensor for the critical micelle concentration (CMC) or critical micelle temperature (CMT). The apparent acidity constant pK'(a) was found to be a relatively good sensor for CMC and also for detection of the sol-gel critical temperature. The Ct photochromic mechanism was analyzed by comparing the photophysics in pure solvents and the pluronic media. Solvatochromic effects show a lack of solvent polarity dependence of the Stokes shift, indicating a low dipolar moment change between the ground and the locally excited state. An internal charge transfer nonradiative process (ICT) competes with Ct photoisomerization and is the dominant process in highly polar solvents, preventing the appearance of photochromism, in contrast with lower polar environments, such as micelles and ethanol. In high viscous environments as those found in the core of the Pluronic F127 micelles or glycerol, both ICT and photoisomerization are reduced, enhancing the Ct fluorescence quantum yield. According to the data from fluorescence measurements and pH jumps, evidence for the Ct distribution among different sites within the pluronic aggregate was found, (i) a hydrophilic/fluid region where Ct has poor fluorescence and isomerization yields, bulk region; (ii) the corona of the micelle where

  19. Magma fluxes and storage beneath Grímsvötn volcano, Iceland, estimated from ice-kept historical tephra

    NASA Astrophysics Data System (ADS)

    Sigmarsson, Olgeir; Carpentier, Marion; Larsen, Guðrún; Guðmundsson, Magnús

    2016-04-01

    Compositional time-series can unravel the dynamics of magma systems beneath active volcanoes. In ideal cases, parameters such as magma flux, reservoir geometry, its lifetime and the transfer time of magma can be inferred from the compositional variations. Quantification of these parameters will improve the understanding of volcano behaviour and, thus, the predictions of their future activity. From the Grímsvötn volcano, Iceland, ice-kept historical tephra has been precisely analysed for trace element concentrations and Sr-, Nd- and Pb isotope ratios. Most of the tephra have uniform isotope ratios suggesting co-genetic magma evolution. Temporal variations of the tephra compositions over the last eight centuries reveal linear decrease and increase in compatible and incompatible trace element concentrations, respectively, caused by eruptions of increasingly differentiated basaltic magma with time. The trace element systematic is readily explained by polybaric fractional crystallization suggesting a magma system composed of multiple storage zones beneath Grímsvötn volcano. The simple mechanism of magma differentiation and the temporal variations allow estimation of diminishing melt fraction (F) in the magma system as a function of time. Increasing concentrations of incompatible elements in the basalts suggest that F decreased by 35% over the last 800 years. This corresponds to a slow magma differentiation rate, or ˜4 x10-4 yr-1. Magma production rate for the 20th century suggests that approximately 8 km3 of basalts have erupted since AD 1200, whereas the volume of the magma system has decreased from approximately 100 km3 to 70±20 km3. Assuming a similar future behaviour, Grímsvötn volcano will produce for the next 500-1000 yrs basalts of increasingly evolved composition with higher volatile contents. Consequently, Plinian basaltic eruptions such as that of 2011 are likely to become more frequent.

  20. Cannabinoids and traumatic stress modulation of contextual fear extinction and GR expression in the amygdala-hippocampal-prefrontal circuit.

    PubMed

    Ganon-Elazar, Eti; Akirav, Irit

    2013-09-01

    Considerable evidence suggests that cannabinoids modulate the behavioral and physiological response to stressful events. We have recently shown that activating the cannabinoid system using the CB1/CB2 receptor agonist WIN55,212-2 (WIN) in proximity to exposure to single-prolonged stress (SPS), a rat model of emotional trauma, prevented the stress-induced enhancement of acoustic startle response, the impairment in avoidance extinction and the enhanced negative feedback on the hypothalamic-pituitary-adrenal (HPA) axis (Ganon-Elazar and Akirav, 2012). Some of the effects were found to be mediated by CB1 receptors in the basolateral amygdala (BLA). Here we examined whether cannabinoid receptor activation in a putative brain circuit that includes the BLA, hippocampus and prefrontal cortex (PFC), could prevent the effects of traumatic stress on contextual fear extinction and alterations in glucocorticoid receptor (GR) protein levels. We found that: (i) SPS impaired contextual fear extinction tested one week after trauma exposure and that WIN prevented the stress-induced impairment of extinction when microinjected immediately after trauma exposure into the BLA or hippocampus (5 μg), but not when microinjected into the PFC, (ii) the ameliorating effects of WIN on contextual extinction were prevented by blocking GRs in the BLA and hippocampus, and (iii) SPS up regulated GRs in the BLA, PFC and hippocampus and systemic WIN administration (0.5 mg/kg) after trauma exposure normalized GR levels in the BLA and hippocampus, but not in the PFC. Cannabinoid receptor activation in the aftermath of trauma exposure may regulate the emotional response to the trauma and prevent stress-induced impairment of extinction and GR up regulation through the mediation of CB1 receptors in the BLA and hippocampus. Taken together, the findings suggest that the interaction between the cannabinoid and glucocorticoid systems is crucial in the modulation of emotional trauma.

  1. Effect of Load Range on Probabilistic Fatigue Crack Growth Resistance in Flux Cored Arc Welded Api 2w GR. Steel

    NASA Astrophysics Data System (ADS)

    Kim, Seon-Jin; Sohn, Sang-Hoon; Sohn, Hye-Jeong

    The aim of this paper is to investigate the effects of the load range on the spatial variation of fatigue crack growth resistance in three different zones, WM, HAZ and BM for flux cored arc welded API 2W Gr. 50 steel using the stochastic model based on reliability theory. Experimental fatigue crack growth tests were performed on ASTM standard CT specimens. The results indicates that the load range has strong dependency on probabilistic fatigue crack growth for the three different zones WM, HAZ and BM, and also the spatial variation of fatigue crack growth resistance.

  2. Study of the Phototransference in GR-200 Dosimetric Material and its Convenience for Dose Re-estimation

    SciTech Connect

    Baly, L.; Otazo, M. R.; Molina, D.; Pernas, R.

    2006-09-08

    A study of the phototransference of charges from deep to dosimetric traps in GR-200 material is presented and its convenience for dose re-estimation in the dose range between 2 and 100mSv is also analyzed. The recovering coefficient (RC) defined as the ratio between the phototransferred thermoluminescence (PTTL) and the original thermoluminescence (TL) of the dosimetric trap was used to evaluate the ratio of phototransferred charges from deep traps and the original charges in the dosimetric traps. The results show the convenience of this method for dose re-estimation for this material in the selected range of doses.

  3. Phenylthiolate as a sigma- and pi- donor ligand: synthesis of a 3-D organometallic coordination polymer [K2Fe(SPh)4]n.

    PubMed

    Yu, Xiao-Yan; Jin, Guo-Xin; Weng, Lin-Hong

    2004-07-01

    The synthesis and crystal structure of the first mixed-metal organometallic polymer network containing phenylthiolato ligands, [K2Fe(SPh)4]n, are investigated. The simple phenylthiolate acts as a sigma- and pi-donor ligand to give a 3-D potassium iron coordination polymer with both metal-carbon and metal-sulfur coordination interactions.

  4. Inversion of exchange bias and complex magnetization reversal in full-nitride epitaxial γ‧-Fe4N/CoN bilayers

    NASA Astrophysics Data System (ADS)

    Li, Z. R.; Mi, W. B.; Wang, X. C.; Bai, H. L.

    2015-04-01

    Exchange bias has been observed in the full-nitride epitaxial γ‧-Fe4N/CoN bilayers. With the increase of temperature, the sign of exchange bias (EB) is inverse, which is independent on the cooling field and training effect. This novel behavior appears in the bilayers with different CoN and γ‧-Fe4N thicknesses. The inversion of EB sign not only occurs at low temperatures, but also takes place even at 200 K for the 10 and 12 nm thick CoN layer. With the decreased γ‧-Fe4N layer thickness, the inversion temperature of EB sign shows a roughly increased tendency. For the bilayer with a 4 nm-thick γ‧-Fe4N, the interfacial magnetization reversal presents a complex trend, which is considered as the combined actions of the disordered ferromagnetic spins and various competed magnetic structures. This new manifestation of EB has been discussed in terms of the complicated interfacial spin structures and frustration effects due to the competition between the ferromagnetic and antiferromagnetic exchange interactions at the interface.

  5. Development of ferret as a human lung cancer model by injecting4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development of new animal lung cancer models that are relevant to human lung carcinogenesis is important for lung cancer research. Previously we have shown the induction of lung tumor in ferrets (Mustela putorius furo) exposed to both tobacco smoke and a tobacco carcinogen (4-(N-methyl-N-nitrosamino...

  6. Revealing the local properties of β-HP4N7, a promising candidate for high pressure synthesis of new materials

    NASA Astrophysics Data System (ADS)

    Morales-García, A.; del Corro, E.

    2015-04-01

    A computational investigation of β-HP4N7 system is accurately performed using the density functional theory formalism coupled with quantum theory of atoms in molecules. The aim of this work is to understand the behavior of β-HP4N7 under compression. At ambient conditions, the N atoms occupy around 81% of the unit cell volume; for this reason the N atoms are the ones contributing significantly to the bulk properties. The particular tetrahedron (PN4) connection promotes high flexibility to this structure. The atoms composing the solid show significant differences in their compressibilities. The high compressibility (or low resistence to pressure) of the N atoms indicates that the reorganization of these atoms is the key in the densification process that takes place when pressure is increased. When compresing the β-HP4N7 from 0 to 130 GPa the formation of PN6 units is observed, leading to a phase transition. The analysis of the elastic constants reveals the stability of this new phase at 110 GPa. This study shows that β-HP4N7 could be a potential candidate for high pressure synthesis of new phases where P atoms would be 6-fold coordinated.

  7. Plasticity and ab initio characterizations on Fe 4N produced on the surface of nanocrystallized 18Ni-maraging steel plasma nitrided at lower temperature

    NASA Astrophysics Data System (ADS)

    Yan, M. F.; Wu, Y. Q.; Liu, R. L.

    2009-08-01

    18Ni-maraging steel has been entirely nanocrystallized by a series of processes including solution treatment, hot-rolling deformation, cold-drawn deformation and direct electric heating. The plasma nitriding of nanocrystallized 18Ni-maraging steel was carried out at 410 °C for 3 h and 6 h in a mixture gas of 20% N 2 + 80% H 2 with a pressure of 400 Pa. The surface phase constructions and nitrogen concentration profile in surface layer were analyzed using an X-ray diffractometer (XRD) and the glow discharge spectrometry (GDS), respectively. The results show that an about 2 μm thick compound layer (mono-phase γ'-Fe 4N) can be produced on the top of the surface layer of nanocrystallized 18Ni-maraging steel plasma nitrided at 410 °C for 6 h. The measured hardness value of the nitrided surface is 11.6 GPa. More importantly, the γ'-Fe 4N phase has better plasticity, i.e., its plastic deformation energy calculated from the load-displacement curve obtained by nano-indentation tester is close to that of nanocrystallized 18Ni-maraging steel. Additionally, the mechanical properties of γ'-Fe 4N phase were also characterized by first-principles calculations. The calculated results indicate that the hardness value and the ratio of bulk to shear modulus ( B/ G) of the γ'-Fe 4N phase are 10.15 GPa and 3.12 (>1.75), respectively. This demonstrates that the γ'-Fe 4N phase has higher hardness and better ductility.

  8. αB-Crystallin regulates expansion of CD11b⁺Gr-1⁺ immature myeloid cells during tumor progression.

    PubMed

    Dieterich, Lothar C; Schiller, Petter; Huang, Hua; Wawrousek, Eric F; Loskog, Angelica; Wanders, Alkwin; Moons, Lieve; Dimberg, Anna

    2013-01-01

    The molecular chaperone αB-crystallin has emerged as a target for cancer therapy due to its expression in human tumors and its role in regulating tumor angiogenesis. αB-crystallin also reduces neuroinflammation, but its role in other inflammatory conditions has not been investigated. Here, we examined whether αB-crystallin regulates inflammation associated with tumors and ischemia. We found that CD45(+) leukocyte infiltration is 3-fold increased in tumors and ischemic myocardium in αB-crystallin-deficient mice. Notably, αB-crystallin is prominently expressed in CD11b(+) Gr-1(+) immature myeloid cells (IMCs), known as regulators of angiogenesis and immune responses, while lymphocytes and mature granulocytes show low αB-crystallin expression. αB-Crystallin deficiency results in a 3-fold higher accumulation of CD11b(+) Gr-1(+) IMCs in tumors and a significant rise in CD11b(+) Gr-1(+) IMCs in spleen and bone marrow. Similarly, we noted a 2-fold increase in CD11b(+) Gr-1(+) IMCs in chronically inflamed livers in αB-crystallin-deficient mice. The effect of αB-crystallin on IMC accumulation is limited to pathological conditions, as CD11b(+) Gr-1(+) IMCs are not elevated in naive mice. Through ex vivo differentiation of CD11b(+) Gr-1(+) cells, we provide evidence that αB-crystallin regulates systemic expansion of IMCs through a cell-intrinsic mechanism. Our study suggests a key role of αB-crystallin in limiting expansion of CD11b(+) Gr-1(+) IMCs in diverse pathological conditions.

  9. Theoretical prediction of Grüneisen parameter for SiO2.TiO2 bulk metallic glasses

    NASA Astrophysics Data System (ADS)

    Singh, Chandra K.; Pandey, Anjani K.; Pandey, Brijesh K.

    2016-05-01

    The Grüneisen parameter (γ) is very important to decide the limitations for the prediction of thermoelastic properties of bulk metallic glasses. It can be defined in terms of microscopic and macroscopic parameters of the material in which former is based on vibrational frequencies of atoms in the material while later is closely related to its thermodynamic properties. Different formulation and equation of states are used by the pioneer researchers of this field to predict the true sense of Gruneisen parameter for BMG but for SiO2.TiO2 very few and insufficient information is available till now. In the present work we have tested the validity of two different isothermal EOS viz. Poirrior-Tarantola EOS and Usual-Tait EOS to predict the true value of Gruneisen parameter for SiO2.TiO2 as a function of compression. Using different thermodynamic limitations related to the material constraints and analyzing obtained result it is concluded that the Poirrior-Tarantola EOS gives better numeric values of Grüneisen parameter (γ) for SiO2.TiO2 BMG.

  10. An exon 53 frameshift mutation in CUBN abrogates cubam function and causes Imerslund-Gräsbeck syndrome in dogs

    PubMed Central

    Fyfe, John C.; Hemker, Shelby L.; Venta, Patrick J.; Fitzgerald, Caitlin A.; Outerbridge, Catherine A.; Myers, Sherry L.; Giger, Urs

    2013-01-01

    Cobalamin malabsorption accompanied by selective proteinuria is an autosomal recessive disorder known as Imerslund-Gräsbeck syndrome in humans and was previously described in dogs due to amnionless (AMN) mutations. The resultant vitamin B12 deficiency causes dyshematopoiesis, lethargy, failure to thrive, and life-threatening metabolic disruption in the juvenile period. We studied 3 kindreds of border collies with cobalamin malabsorption and mapped the disease locus in affected dogs to a 2.9 Mb region of homozygosity on canine chromosome 2. The region included CUBN, the locus encoding cubilin, a peripheral membrane protein that in concert with AMN forms the functional intrinsic factor-cobalamin receptor expressed in ileum and a multi-ligand receptor in renal proximal tubules. Cobalamin malabsorption and proteinuria comprising CUBN ligands were demonstrated by radiolabeled cobalamin uptake studies and SDS-PAGE, respectively. CUBN mRNA and protein expression were reduced ~10 fold and ~20 fold, respectively, in both ileum and kidney of affected dogs. DNA sequencing demonstrated a single base deletion in exon 53 predicting a translational frameshift and early termination codon likely triggering nonsense mediated mRNA decay. The mutant allele segregated with disease in the border collie kindred. The border collie disorder indicates that a CUBN mutation far C-terminal from the intrinsic factor-cobalamin binding site can abrogate receptor expression and cause Imerslund-Gräsbeck syndrome. PMID:23746554

  11. Genetic map of the region around grizzled (gr) and mocha (mh) on mouse chromosome 10, homologous to human 19p13.3

    SciTech Connect

    Kapfhamer, D.; Burmeister, M.

    1994-10-01

    Grizzled (gr) is a recessive mouse mutation resulting in a gray coat color and reduced perinatal viability. Mocha (mh) is one of several recessive mouse mutants characterized by platelet storage pool disorder, pigment abnormalities, reduced fertility, kidney function deficiencies, and, in some mutants, inner ear and natural killer cell deficiencies. Murine platelet storage pool deficient mutants may be models for Chediak-Higashi and Hermansky-Pudlak syndromes in humans. The genes for gr and mh are very closely linked to each other (0 {+-} 1.2 cM). However, their relative position with respect to molecular markers was previously unknown. Thus, genetic mapping of the gr locus will also yield information about the mh location. To map these two genes genetically, we have performed an intersubspecific backcross of grizzled mice with Mus musculus castaneus. In 539 progeny tested, we found no recombination between the gr gene, the gene for anti-Muellerian hormone (Amh), and the microsatellite markers D10Mit7, D10Mit21, and D10Mit23. One recombination event for each of the flanking markers Basigin (Bsg) and D10Mit22 was identified. These closely linked markers should provide entry points for positional cloning of the gr and mh genes. The region linked to grizzled is homologous to a gene-rich region on human Chromosome 19p13.3.

  12. pOp6/LhGR: a stringently regulated and highly responsive dexamethasone-inducible gene expression system for tobacco.

    PubMed

    Samalova, Marketa; Brzobohaty, Bretislav; Moore, Ian

    2005-03-01

    We describe pOp/LhGR, a dexamethasone-inducible derivative of the pOp/LhG4 transcription activation system, and its use in tobacco to regulate expression of uidA (encoding beta-glucuronidase; GUS) and the cytokinin-biosnythetic gene ipt. The pOp/LhGR system exhibited stringent regulation and strong induced phenotypes in soil and tissue culture. In conjunction with an improved target promoter, pOp6, that carries six copies of an optimized lac operator sequence the pOp6/LhGR system directed induced GUS activities that exceeded those obtained with pOp/LhG4 or the CaMV 35S promoter but without increased uninduced activity. A single dose of dexamethasone was sufficient to direct cytotoxic levels of ipt expression in soil-grown plants although uninduced plants grew normally throughout a complete life cycle. In vitro, induced transcripts were detectable within an hour of dexamethasone application and 1 nM dexamethasone was sufficient for half maximal induction of GUS activity. Various methods of dexamethasone application were successfully applied under tissue culture and greenhouse conditions. We observed no inhibitory effects of dexamethasone or LhGR on plant development even with the highest concentrations of inducer, although tobacco seedlings were adversely affected by ethanol used as a solvent for dexamethasone stock solutions. The pOp/LhGR system provides a highly sensitive, efficient, and tightly regulated chemically inducible transgene expression system for tobacco plants. PMID:15743454

  13. Persistence of Lactobacillus fermentum RC-14 and Lactobacillus rhamnosus GR-1 but Not L. rhamnosus GG in the Human Vagina as Demonstrated by Randomly Amplified Polymorphic DNA

    PubMed Central

    Gardiner, Gillian E.; Heinemann, Christine; Bruce, Andrew W.; Beuerman, Dee; Reid, Gregor

    2002-01-01

    Lactobacillus rhamnosus GR-1 and L. fermentum RC-14 are well-characterized probiotic strains with efficacy in the prevention and treatment of urogenital infections in women. The aim of the present study was to apply a molecular biology-based methodology for the detection of these strains and L. rhamnosus GG (a commercially available intestinal probiotic) in the human vagina in order to assess probiotic persistence at this site. Ten healthy women inserted vaginally a capsule containing either a combination of strains GR-1 and RC-14 or the GG strain for 3 consecutive nights. Vaginal swabs taken before and at various time points after probiotic insertion were analyzed, and the Lactobacillus flora was assessed by randomly amplified polymorphic DNA (RAPD) analysis. This method generated discrete DNA fingerprints for GR-1, RC-14, and GG and enabled successful detection of these strains in the vagina. Strain GR-1 and/or strain RC-14 was found to persist in the vaginal tract for up to 19 days after vaginal instillation, while L. rhamnosus GG was detectable for up to 5 days postadministration. In conclusion, the fates of probiotic L. rhamnosus and L. fermentum strains were successfully monitored in the human vagina by RAPD analysis. This technique provides molecular biology-based evidence that RC-14 and GR-1, strains selected as urogenital probiotics, persist in the human vagina and may be more suited to vaginal colonization than L. rhamnosus GG. This highlights the importance of proper selection of strains for urogenital probiotic applications. PMID:11777835

  14. The HPV16 E7 Oncoprotein Disrupts Dendritic Cell Function and Induces the Systemic Expansion of CD11b+Gr1+ Cells in a Transgenic Mouse Model

    PubMed Central

    Damian-Morales, Gabriela; Serafín-Higuera, Nicolás; Moreno-Eutimio, Mario Adán; Cortés-Malagón, Enoc M.; Bonilla-Delgado, José; Rodríguez-Uribe, Genaro; Ocadiz-Delgado, Rodolfo; Lambert, Paul F.

    2016-01-01

    Objective. The aim of this study was to analyze the effects of the HPV16 E7 oncoprotein on dendritic cells (DCs) and CD11b+Gr1+ cells using the K14E7 transgenic mouse model. Materials and Methods. The morphology of DCs was analyzed in male mouse skin on epidermal sheets using immunofluorescence and confocal microscopy. Flow cytometry was used to determine the percentages of DCs and CD11b+Gr1+ cells in different tissues and to evaluate the migration of DCs. Results. In the K14E7 mouse model, the morphology of Langerhans cells and the migratory activity of dendritic cells were abnormal. An increase in CD11b+Gr1+ cells was observed in the blood and skin of K14E7 mice, and molecules related to CD11b+Gr1+ chemoattraction (MCP1 and S100A9) were upregulated. Conclusions. These data suggest that the HPV16 E7 oncoprotein impairs the function and morphology of DCs and induces the systemic accumulation of CD11b+Gr1+ cells. PMID:27478837

  15. The HPV16 E7 Oncoprotein Disrupts Dendritic Cell Function and Induces the Systemic Expansion of CD11b(+)Gr1(+) Cells in a Transgenic Mouse Model.

    PubMed

    Damian-Morales, Gabriela; Serafín-Higuera, Nicolás; Moreno-Eutimio, Mario Adán; Cortés-Malagón, Enoc M; Bonilla-Delgado, José; Rodríguez-Uribe, Genaro; Ocadiz-Delgado, Rodolfo; Lambert, Paul F; Gariglio, Patricio

    2016-01-01

    Objective. The aim of this study was to analyze the effects of the HPV16 E7 oncoprotein on dendritic cells (DCs) and CD11b(+)Gr1(+) cells using the K14E7 transgenic mouse model. Materials and Methods. The morphology of DCs was analyzed in male mouse skin on epidermal sheets using immunofluorescence and confocal microscopy. Flow cytometry was used to determine the percentages of DCs and CD11b(+)Gr1(+) cells in different tissues and to evaluate the migration of DCs. Results. In the K14E7 mouse model, the morphology of Langerhans cells and the migratory activity of dendritic cells were abnormal. An increase in CD11b(+)Gr1(+) cells was observed in the blood and skin of K14E7 mice, and molecules related to CD11b(+)Gr1(+) chemoattraction (MCP1 and S100A9) were upregulated. Conclusions. These data suggest that the HPV16 E7 oncoprotein impairs the function and morphology of DCs and induces the systemic accumulation of CD11b(+)Gr1(+) cells. PMID:27478837

  16. Gr-1dimCD11b+ Immature Myeloid-Derived Suppressor Cells, but not Neutrophils, are Markers of Lethal Tuberculosis Infection in Mice

    PubMed Central

    Tsiganov, Evgeny N.; Verbina, Elena M.; Radaeva, Tatyana V.; Sosunov, Vasily V.; Kosmiadi, George A.; Nikitina, Irina Yu.; Lyadova, Irina V.

    2014-01-01

    Tuberculosis disease (TB) may progress at different rates and have different outcomes. Neutrophils have been implicated in TB progression; however, data on their role during TB are controversial. Here we show that in mice, TB progression is associated with the accumulation of cells that express neutrophilic markers Gr-1 and Ly-6G, but do not belong to conventional neutrophils. The cells exhibit unsegmented nuclei, have Gr-1dimLy-6GdimCD11b+ phenotype and express F4/80, CD49d, Ly-6C, CD117, CD135 markers characteristic not of neutrophils, but of immature myeloid cells. The cells accumulate in the lungs, bone marrow, spleen and blood at the advanced (pre-lethal) stage of M. tuberculosis infection and represent a heterogeneous population of myeloid cells at different stages of their differentiation. The accumulation of Gr-1dimCD11b+ cells is accompanied by the disappearance of conventional neutrophils (Gr-1hiLy-6Ghi-expressing cells). The Gr-1dimCD11b+ cells suppress T cell proliferation and IFN-γ production in vitro via NO-dependent mechanisms, i.e. they exhibit characteristics of myeloid-derived suppressor cells (MDSCs). These results document the generation of MDSCs during TB, suggesting their role in TB pathogenesis, and arguing that neutrophils do not contribute to TB pathology at the advanced disease stage. PMID:24711621

  17. Assessment of efficacy, safety, and tolerability of 4-n-butylresorcinol 0.3% cream: an Indian multicentric study on melasma

    PubMed Central

    Madan Mohan, NT; Gowda, Adarsh; Jaiswal, Ashok Kumar; Sharath Kumar, BC; Shilpashree, P; Gangaboraiah, Bilugumba; Shamanna, Manjula

    2016-01-01

    Introduction Melasma is one of the commonly reported pigmentory disorders in the Indian population. Numerous therapeutic modalities are available. However, very few have produced complete satisfactory response. 4-n-Butylresorcinol 0.3% cream has recently been introduced in India as a new hypopigmenting agent. It is a resorcinol derivative and acts by inhibiting both tyrosinase and tyrosinase-related protein-1. Objective The available published literatures are with 4-n-butylresorcinol 0.1% cream, and there is paucity of clinical studies with 4-n-butylresorcinol 0.3% cream. Furthermore, considering the fact that Indian skin is more prone to irritation with hypopigmenting agents, our study explores the efficacy, safety, and tolerability of 4-n-butylresorcinol 0.3% cream in Indian subjects with melasma. Methods Fifty-two subjects with melasma participated in this open-label, single arm, observational study. All the patients were advised twice daily application of 4-n-butylresorcinol 0.3% cream for 8 weeks over the areas of melasma. Assessment parameters included modified Melasma Area Severity Index (mMASI) score. Digital photographs of all the patients at baseline, week 4, and week 8 were taken. During this 8-week study period, all the adverse events were observed and recorded. Results All the 52 subjects completed the study. Out of 52 subjects, 90.38% were females. The mean age of patients was 38.5±7.8 years. Mean ± standard error of MASI score measurements showed a significant decrease from baseline score of 14.73±0.59 to 11.09±0.53 after week 4 (P<0.001) and 6.48±0.43 at week 8 (P<0.001). The digital photographs of the study subjects taken at week 4 and week 8 also showed decrease in melasma pigmentation compared to baseline photograph and correlated with the changes in the mMASI score. The treatment was well tolerated by all the study subjects. No adverse reactions were reported throughout the study period. Conclusion Our data suggest that the 4-n

  18. Perpendicular magnetic anisotropy of Mn{sub 4}N films on MgO(001) and SrTiO{sub 3}(001) substrates

    SciTech Connect

    Yasutomi, Yoko; Ito, Keita; Sanai, Tatsunori; Toko, Kaoru; Suemasu, Takashi

    2014-05-07

    We grew Mn{sub 4}N epitaxial thin films capped with Au layers on MgO(001) and SrTiO{sub 3}(001) substrates by molecular beam epitaxy. Perpendicular magnetic anisotropy (PMA) was confirmed in all the samples at room temperature from the magnetization versus magnetic field curves using superconducting quantum interference device magnetometer. From the ω-2θ x-ray diffraction (XRD) and ϕ-2θ{sub χ} XRD patterns, the ratios of perpendicular lattice constant c to in-plane lattice constant a, c/a, were found to be about 0.99 for all the samples. These results imply that PMA is attributed to the in-plane tensile strain in the Mn{sub 4}N films.

  19. A novel point mutation in the ligand-binding domain (LBD) of the human glucocorticoid receptor (hGR) causing generalized glucocorticoid resistance: the importance of the C terminus of hGR LBD in conferring transactivational activity.

    PubMed

    Charmandari, Evangelia; Raji, Annaswamy; Kino, Tomoshige; Ichijo, Takamasa; Tiulpakov, Anatoly; Zachman, Keith; Chrousos, George P

    2005-06-01

    Glucocorticoid resistance is a rare, familial or sporadic condition characterized by partial end-organ insensitivity to glucocorticoids. The clinical spectrum of the condition is broad, ranging from completely asymptomatic to severe hyperandrogenism and/or mineralocorticoid excess. The molecular basis of glucocorticoid resistance has been ascribed to mutations in the human glucocorticoid receptor-alpha (hGRalpha) gene, which impair one or more of the molecular mechanisms of GR action, thus altering tissue sensitivity to glucocorticoids. We identified a new case of generalized glucocorticoid resistance in a young woman who presented with a long-standing history of fatigue, anxiety, hyperandrogenism, and hypertension. The disease was caused by a novel, heterozygous mutation (T-->C) at nucleotide position 2318 (exon 9) of the hGRalpha gene, which resulted in substitution of leucine by proline at amino acid position 773 in the ligand-binding domain of the receptor. We systematically investigated the molecular mechanisms through which the natural hGRalphaL773P mutant impaired glucocorticoid signal transduction. Compared with the wild-type hGRalpha, hGRalphaL773P demonstrated a 2-fold reduction in the ability to transactivate the glucocorticoid-inducible mouse mammary tumor virus promoter, exerted a dominant negative effect on the wild-type receptor, had a 2.6-fold reduction in the affinity for ligand, showed delayed nuclear translocation (30 vs. 12 min), and, although it preserved its ability to bind to DNA, displayed an abnormal interaction with the GR-interacting protein 1 coactivator in vitro. We conclude that the carboxyl terminus of the ligand-binding domain of hGRalpha is extremely important in conferring transactivational activity by altering multiple functions of this composite transcription factor. PMID:15769988

  20. RADIO AND X-RAY OBSERVATIONS OF THE TYPE Ic SN 2007gr REVEAL AN ORDINARY, NON-RELATIVISTIC EXPLOSION

    SciTech Connect

    Soderberg, A. M.; Brunthaler, A.; Nakar, E.; Chevalier, R. A.; Bietenholz, M. F.

    2010-12-10

    We present extensive radio and X-ray observations of the nearby Type Ic SN 2007gr in NGC 1058 obtained with the Very Large Array (VLA) and the Chandra X-ray Observatory and spanning 5 to 150 days after explosion. Through our detailed modeling of these data, we estimate the properties of the blast wave and the circumstellar environment. We find evidence for a freely expanding and non-relativistic explosion with an average blast wave velocity, v-bar {approx}0.2c, and a total internal energy for the radio emitting material of E {approx} 2 x 10{sup 46} erg assuming equipartition of energy between electrons and magnetic fields ({epsilon}{sub e} = {epsilon}{sub B} = 0.1). The temporal and spectral evolution of the radio emission points to a stellar wind-blown environment shaped by a steady progenitor mass loss rate of M-dot {approx}6x10{sup -7} M{sub sun} yr{sup -1} (wind velocity, v{sub w} = 10{sup 3} km s{sup -1}). These parameters are fully consistent with those inferred for other SNe Ibc and are in line with the expectations for an ordinary, homologous SN explosion. Our results are at odds with those of Paragi et al. who recently reported evidence for a relativistic blast wave in SN 2007gr based on their claim that the radio emission was resolved away in a low signal-to-noise Very Long Baseline Interferometry (VLBI) observation. Here we show that the exotic physical scenarios required to explain the claimed relativistic velocity-extreme departures from equipartition and/or a highly collimated outflow-are excluded by our detailed VLA radio observations. Moreover, we present an independent analysis of the VLBI data and propose that a modest loss of phase coherence provides a more natural explanation for the apparent flux density loss which is evident on both short and long baselines. We conclude that SN 2007gr is an ordinary Type Ibc supernova.

  1. The first quaternary lanthanide(III) nitride iodides: NaM{sub 4}N{sub 2}I{sub 7} (M=La-Nd)

    SciTech Connect

    Schurz, Christian M.; Schleid, Thomas

    2010-10-15

    In attempts to synthesize lanthanide(III) nitride iodides with the formula M{sub 2}NI{sub 3} (M=La-Nd), moisture-sensitive single crystals of the first quaternary sodium lanthanide(III) nitride iodides NaM{sub 4}N{sub 2}I{sub 7} (orthorhombic, Pna2{sub 1}; Z=4; a=1391-1401, b=1086-1094, c=1186-1211 pm) could be obtained. The dominating structural features are {sup 1}{sub {infinity}}{l_brace}[NM{sub 4/2}{sup e}]{sup 3+}{r_brace} chains of trans-edge linked [NM{sub 4}]{sup 9+} tetrahedra, which run parallel to the polar 2{sub 1}-axis [001]. Between the chains, direct bonding via special iodide anions generates cages, in which isolated [NaI{sub 6}]{sup 5-} octahedra are embedded. The IR spectrum of NaLa{sub 4}N{sub 2}I{sub 7} recorded from 100 to 1000 cm{sup -1} shows main bands at {upsilon}=337, 373 and 489 cm{sup -1}. With decreasing radii of the lanthanide trications these bands, which can be assigned as an influence of the vibrations of the condensed [NM{sub 4}]{sup 9+} tetrahedra, are shifted toward higher frequencies for the NaM{sub 4}N{sub 2}I{sub 7} series (M=La-Nd), following the lanthanide contraction. - Abstract: View at the main structural features of the NaM{sub 4}N{sub 2}I{sub 7} series (M=La-Nd): The {sup 1}{sub {infinity}}{l_brace}[NM{sub 4/2}{sup e}]{sup 3+}{r_brace} chains, consisting of trans-edge connected [NM{sub 4}]{sup 9+} tetrahedra, and the special kind of iodide anions, namely (I7){sup -}, form cages, in which isolated [NaI{sub 6}]{sup 5-} octahedra are embedded.

  2. [Seasonal variation patterns of NH4(+) -N/NO3(-) -N ratio and delta 15 NH4(+) value in rainwater in Yangtze River Delta].

    PubMed

    Xie, Ying-Xin; Zhang, Shu-Li; Zhao, Xu; Xiong, Zheng-Qin; Xing, Guang-Xi

    2008-09-01

    By using a customized manual rainwater sampler made of polyvinyl chloride plastic, the molar ratio of NH4(+) -N/NO3(-) -N and the natural 15N abundance of NH4(+) (delta 15 NH4(+) in rainwater was monitored all year round from June 2003 to July 2005 at three observation sites (Changshu, Nanjing, and Hangzhou) in the Yangtze River Delta. The results indicated that at the three sites, the NH4(+) -N/NO3(-) -N ratio and the delta 15 NH4(+) value in rainwater had the similar seasonal variation trend, being more obvious in Changshu (rural monitoring type) site than in Nanjing (urban monitoring type) and Hangzhou (urban-rural monitoring type) sites. The NH4(+) -N/NO3(-) -N ratio peaked from early June to early August, declined gradually afterwards, and reached the bottom in winter; while the delta 15 NH4(+) value was negative from late June to mid-August, turned positive from late August to mid or late November, became negative again when winter dominated from December to March, but turned positive again in next May and negative again in next July. These seasonal variation patterns of NH4(+) -N/NO3(-) -N ratio and delta 15 NH4(+) value were found in relation to the application of chemical nitrogen fertilizers during different crop growth periods, and also, the alternation of seasons and the NH3 volatilization from other NH3 emission sources (including excrements of human and animals, nitrogen- polluted water bodies, and organic nitrogen sources, etc.), which could be taken as an indicator of defining the sources and form composition of NH4(+) in atmospheric wet deposition and the intensity of various terrestrial NH3 emission sources.

  3. Synthesis and characterization of a cadmium bipyridinium compound (CdCl{sub 4})(N,N'-dimethyl-2,2'-bipyridinium)

    SciTech Connect

    Luo, Hui; Zhu, Li-Cheng; Wang, Qi

    2015-12-15

    A cadmium bipyridinium compound (CdCl{sub 4})(N,N'-dimethyl-2,2'-bipyridinium), in which the (N,N'-dimethyl-2,2'-bipyridinium){sup 2+} moieties were generated in situ, has been prepared via solvothermal reactions and structurally characterized with single crystal X-ray diffraction method. Fluorescence measurement revealed a broad and strong emission band in the blue region.

  4. Synthesis and evaluation of substituted 4-(N-benzylamino)cinnamate esters as potential anti-cancer agents and HIV-1 integrase inhibitors.

    PubMed

    Faridoon; Edkins, Adrienne L; Isaacs, Michelle; Mnkandhla, Dumisani; Hoppe, Heinrich C; Kaye, Perry T

    2016-08-01

    Encouraging selectivity and low micromolar activity against HeLa cervical carcinoma (IC50⩾3.0μM) and the aggressive MDA-MB-231 triple negative breast carcinoma (IC50⩾9.6μM) cell lines has been exhibited by a number of readily accessible 4-(N-benzylamino)cinnamate esters. The potential of the ligands as HIV-1 integrase inhibitors has also been examined. PMID:27317645

  5. Pharmacological stress is required for the anti-alcohol effect of the α3β4* nAChR partial agonist AT-1001.

    PubMed

    Cippitelli, Andrea; Brunori, Gloria; Gaiolini, Kelly A; Zaveri, Nurulain T; Toll, Lawrence

    2015-06-01

    Alcohol and nicotine are often taken together. The mechanisms underlying this frequent co-abuse are not well known. Genetic and pharmacological evidence suggests that the nicotinic acetylcholine receptors (nAChRs) containing the α3 and β4 subunits play a role in alcohol as well as nicotine addiction. AT-1001 is a high affinity α3β4 nAChR partial agonist recently found to block nicotine self-administration and relapse-like behavior in rats. Here, to study the involvement of α3β4 nAChRs in the mechanisms that regulate alcohol abuse we evaluated the effects of AT-1001 on alcohol taking and seeking in Sprague-Dawley rats. AT-1001 reduced operant alcohol self-administration at the highest dose examined (3.0 mg/kg), an effect also observed for food self-administration. A dose of 1.5 mg/kg AT-1001, which had no effect on alcohol or food self-administration, essentially eliminated reinstatement of alcohol seeking induced by yohimbine (0.625 mg/kg) whereas, reinstatement induced by alcohol-associated cues was not altered, nor did AT-1001 induce reinstatement of extinguished self-administration on its own. Finally, AT-1001 showed an anxiolytic activity when measured in the presence or absence of yohimbine stress in the elevated plus maze paradigm. Together, these observations do not support a specific involvement of the α3β4 nAChR in mediating alcohol reward or cue-induced relapse to alcohol seeking but rather indicate that the α3β4 nAChR partial agonism may constitute an attractive approach for treating alcohol use disorders exacerbated by elevated stress response.

  6. High capacity and superlong cycle life of Li3VO4/N-C hybrids as anode for high performance Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhang, Jicheng; Ni, Shibing; Ma, Jianjun; Yang, Xuelin; Zhang, Lulu

    2016-01-01

    High capacity and superlong cycle life of Li3VO4 have been actualized via carbon hybridization and N doping. The Li3VO4/N doped C (Li3VO4/N-C) that fabricated via an in situ carbonization method based on an intermedial solution phase delivers initial discharge and charge capacities of 686 and 540 mAh g-1 at a specific current of 0.15 A g-1, which maintain of 538 and 536 mAh g-1 after 800 cycles, showing excellent cycle stability. Meanwhile, the Li3VO4/N-C exhibits superior rate performance and long life performance. After 150 cycles at various specific currents from 0.1 to 2.0 A g-1, the discharge and charge capacities can restore 100% when reverting the specific current to 0.1 A g-1. After 1100 cycles at a specific current of 2.0 A g-1, the discharge and charge capacities can maintain of 340 and 337 mAh g-1, showing no capacity attenuation in cycling.

  7. Role of nitrogen in the formation of HC-N films by CH(4)/N(2) barrier discharge plasma: aliphatic tendency.

    PubMed

    Majumdar, Abhijit; Das, Gobind; Basvani, Kaleswara Rao; Heinicke, Joachim; Hippler, Rainer

    2009-12-01

    We have studied the influence of nitrogen on the chemical properties of the hydrogenated carbon nitride (a-CN(x):H) film deposited by CH(4)/N(2) dielectric barrier discharge (DBD) plasma. X-ray photoelectron spectroscopy (XPS) indicates that carbon and nitrogen form an unpolarized covalent bond in these C-N(x) materials, and the observed chemical shift in the C 1s and N 1s binding energy is explained with respect to N 1s incorporation. Furthermore, the average nitrogen content (N/C approximately 0.76) in the films was systematically varied by changing the nitrogen partial pressure (CH(4)/N(2) approximately from 5:1 to 1:7) which is well supported by the elemental analysis. Fourier transform infrared (FTIR) absorption spectra exhibit significant changes in different C-N, C identical withN, and NH/OH molecular bands at higher nitrogen concentration in the film. The isonitrile and nitrile groups (-NC and -CN) are increased with the increase of deposition time. In addition, the elemental analysis, proton NMR, and thermolysis mass spectrum show that the composition of the film with the ratio CH(4)/N(2) approximately 1:1 is C, 67.68; H, 9.88; N, 16.53 (in wt %) and that the film is composed of polymers, probably containing linear chains which are cleaved off on heating in vacuum. PMID:19894689

  8. Coexistence of Three Ferroic Orders in the Multiferroic Compound [(CH3 )4 N][Mn(N3 )3 ] with Perovskite-Like Structure.

    PubMed

    Gómez-Aguirre, L Claudia; Pato-Doldán, Breogán; Stroppa, Alessandro; Yang, Li-Ming; Frauenheim, Thomas; Mira, Jorge; Yáñez-Vilar, Susana; Artiaga, Ramón; Castro-García, Socorro; Sánchez-Andújar, Manuel; Señarís-Rodríguez, María Antonia

    2016-06-01

    The perovskite azido compound [(CH3 )4 N][Mn(N3 )3 ], which undergoes a first-order phase change at Tt =310 K with an associated magnetic bistability, was revisited in the search for additional ferroic orders. The driving force for such structural transition is multifold and involves a peculiar cooperative rotation of the [MnN6 ] octahedral as well as order/disorder and off-center shifts of the [(CH3 )4 N](+) cations and bridging azide ligands, which also bend and change their coordination mode. According to DFT calculations the latter two give rise to the appearance of electric dipoles in the low-temperature (LT) polymorph, the polarization of which nevertheless cancels out due to their antiparallel alignment in the crystal. The conversion of this antiferroelectric phase to the paraelectric phase could be responsible for the experimental dielectric anomaly detected at 310 K. Additionally, the structural change involves a ferroelastic phase transition, whereby the LT polymorph exhibits an unusual and anisotropic thermal behavior. Hence, [(CH3 )4 N][Mn(N3 )3 ] is a singular material in which three ferroic orders coexist even above room temperature. PMID:27072487

  9. Structural and magnetic properties of ferrimagnetic ε-phase Mn4N and antiferromagnetic ζ-phase Mn10N thin films on MgO(001)

    NASA Astrophysics Data System (ADS)

    Foley, Andrew; Corbett, Joseph; Richard, Andrea L.; Alam, Khan; Ingram, David C.; Smith, Arthur R.

    2016-07-01

    Single phase ε-Mn4N and ζ-Mn10N thin films are grown on MgO(001) using molecular beam epitaxy. The films are identified and characterized using reflection high-energy electron diffraction, x-ray diffraction, back scattered electron scanning electron microscopy, atomic/magnetic force microscopy and Rutherford backscattering spectrometry. These films are found to be highly smooth with root-mean-squared roughnesses 3.39 nm and below. The quality of ε-Mn4N grown is strongly dependent on substrate temperature during growth. Epitaxial growth of substantial grains composed of the antiferromagnetic η-phase Mn3N2 side by side with ferrimagnetic ε-phase grains is observed when growth temperature is below 480 °C. Ising domains isolated within areas roughly 0.5 μm across are observed in the ferrimagnetic ε-phase grains of samples consisting of a mix of η- and ε-phase grains. Magnetic domains following semi-continuous paths, which are 0.7-7.2 μm across, are observed in single phase ε-Mn4N. Measurements of the ζ-phase detail the structure and magnetism of the material as high Mn content γ-type ζ-phase with a regular surface corrugation along the [100]-direction and antiferromagnetic.

  10. Spectroscopic studies of non-volatile residue formed by photochemistry of solid C4N2: A model of condensed aerosol formation on Titan

    NASA Astrophysics Data System (ADS)

    Couturier-Tamburelli, Isabelle; Gudipati, Murthy S.; Lignell, Antti; Jacovi, Ronen; Piétri, Nathalie

    2014-05-01

    Following our recent communication (Gudipati, M.S. et al. [2013]. Nat. Commun. 4, 1648. http://dx.doi.org/10.1038/ncomms2649) on the discovery of condensed-phase non-volatile polymeric material with similar spectral features as tholins, we present here a comprehensive spectroscopic study of photochemical formation of polymeric material from condensed dicyanoacetylene (C4N2) ice films. C4N2 is chosen as starting material for the laboratory simulations because of the detection of this and similar molecules (nitriles and cyanoacetylenes) in Titan’s atmosphere. UV-Vis and infrared spectra obtained during long-wavelength (>300 nm) photon irradiation and subsequent warming of the ice films are used to analyze changes in C4N2 ice, evolution of tholins, and derive photopolymerization mechanisms. Our data analysis revealed that many processes occur during the photolysis of condensed Titan’s aerosol analogs, including isomerization and polymerization leading to the formation of long-chain as well as aromatic cyclic polymer molecules. In the light of tremendous new data from the Cassini mission on the seasonal variations in Titan’s atmosphere, our laboratory study and its results provide fresh insight into the formation and evolution of aerosols and haze in Titan’s atmosphere.

  11. Calculation of the thermal conductivity of low-density CH4-N2 gas mixtures using an improved kinetic theory approach.

    PubMed

    Hellmann, Robert; Bich, Eckard; Vesovic, Velisa

    2016-04-01

    The thermal conductivity of low-density CH4-N2 gas mixtures has been calculated by means of the classical trajectory method using state-of-the-art intermolecular potential energy surfaces for the CH4-CH4, N2-N2, and CH4-N2 interactions. Results are reported in the temperature range from 70 K to 1200 K. Since the thermal conductivity is influenced by the vibrational degrees of freedom of the molecules, which are not included in the rigid-rotor classical trajectory computations, a new correction scheme to account for vibrational degrees of freedom in a dilute gas mixture is presented. The calculations show that the vibrational contribution at the highest temperature studied amounts to 46% of the total thermal conductivity of an equimolar mixture compared to 13% for pure nitrogen and 58% for pure methane. The agreement with the available experimental thermal conductivity data at room temperature is good, within ±1.4%, whereas at higher temperatures, larger deviations up to 4.5% are observed, which can be tentatively attributed to deteriorating performance of the measuring technique employed. Results are also reported for the magnitude and temperature dependence of the rotational collision number, Z(rot), for CH4 relaxing in collisions with N2 and for N2 relaxing in collisions with CH4. Both collision numbers increase with temperature, with the former being consistently about twice the value of the latter. PMID:27059564

  12. Local electronic states of Fe{sub 4}N films revealed by x-ray absorption spectroscopy and x-ray magnetic circular dichroism

    SciTech Connect

    Ito, Keita; Toko, Kaoru; Suemasu, Takashi; Takeda, Yukiharu; Saitoh, Yuji; Oguchi, Tamio; Kimura, Akio

    2015-05-21

    We performed x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) measurements at Fe L{sub 2,3} and N K-edges for Fe{sub 4}N epitaxial films grown by molecular beam epitaxy. In order to clarify the element specific local electronic structure of Fe{sub 4}N, we compared experimentally obtained XAS and XMCD spectra with those simulated by a combination of a first-principles calculation and Fermi's golden rule. We revealed that the shoulders observed at Fe L{sub 2,3}-edges in the XAS and XMCD spectra were due to the electric dipole transition from the Fe 2p core-level to the hybridization state generated by σ* anti-bonding between the orbitals of N 2p at the body-centered site and Fe 3d on the face-centered (II) sites. Thus, the observed shoulders were attributed to the local electronic structure of Fe atoms at II sites. As to the N K-edge, the line shape of the obtained spectra was explained by the dipole transition from the N 1s core-level to the hybridization state formed by π* and σ* anti-bondings between the Fe 3d and N 2p orbitals. This hybridization plays an important role in featuring the electronic structures and physical properties of Fe{sub 4}N.

  13. Calculation of the thermal conductivity of low-density CH4-N2 gas mixtures using an improved kinetic theory approach.

    PubMed

    Hellmann, Robert; Bich, Eckard; Vesovic, Velisa

    2016-04-01

    The thermal conductivity of low-density CH4-N2 gas mixtures has been calculated by means of the classical trajectory method using state-of-the-art intermolecular potential energy surfaces for the CH4-CH4, N2-N2, and CH4-N2 interactions. Results are reported in the temperature range from 70 K to 1200 K. Since the thermal conductivity is influenced by the vibrational degrees of freedom of the molecules, which are not included in the rigid-rotor classical trajectory computations, a new correction scheme to account for vibrational degrees of freedom in a dilute gas mixture is presented. The calculations show that the vibrational contribution at the highest temperature studied amounts to 46% of the total thermal conductivity of an equimolar mixture compared to 13% for pure nitrogen and 58% for pure methane. The agreement with the available experimental thermal conductivity data at room temperature is good, within ±1.4%, whereas at higher temperatures, larger deviations up to 4.5% are observed, which can be tentatively attributed to deteriorating performance of the measuring technique employed. Results are also reported for the magnitude and temperature dependence of the rotational collision number, Z(rot), for CH4 relaxing in collisions with N2 and for N2 relaxing in collisions with CH4. Both collision numbers increase with temperature, with the former being consistently about twice the value of the latter.

  14. Calculation of the thermal conductivity of low-density CH4-N2 gas mixtures using an improved kinetic theory approach

    NASA Astrophysics Data System (ADS)

    Hellmann, Robert; Bich, Eckard; Vesovic, Velisa

    2016-04-01

    The thermal conductivity of low-density CH4-N2 gas mixtures has been calculated by means of the classical trajectory method using state-of-the-art intermolecular potential energy surfaces for the CH4-CH4, N2-N2, and CH4-N2 interactions. Results are reported in the temperature range from 70 K to 1200 K. Since the thermal conductivity is influenced by the vibrational degrees of freedom of the molecules, which are not included in the rigid-rotor classical trajectory computations, a new correction scheme to account for vibrational degrees of freedom in a dilute gas mixture is presented. The calculations show that the vibrational contribution at the highest temperature studied amounts to 46% of the total thermal conductivity of an equimolar mixture compared to 13% for pure nitrogen and 58% for pure methane. The agreement with the available experimental thermal conductivity data at room temperature is good, within ±1.4%, whereas at higher temperatures, larger deviations up to 4.5% are observed, which can be tentatively attributed to deteriorating performance of the measuring technique employed. Results are also reported for the magnitude and temperature dependence of the rotational collision number, Zrot, for CH4 relaxing in collisions with N2 and for N2 relaxing in collisions with CH4. Both collision numbers increase with temperature, with the former being consistently about twice the value of the latter.

  15. Synthetic precursors for TCNQF4(2-) compounds: synthesis, characterization, and electrochemical studies of (Pr4N)2TCNQF4 and Li2TCNQF4.

    PubMed

    Lu, Jinzhen; Le, Thanh Hai; Traore, Daouda A K; Wilce, Matthew; Bond, Alan M; Martin, Lisandra L

    2012-12-01

    Careful control of the reaction stoichiometry and conditions enables the synthesis of both LiTCNQF(4) and Li(2)TCNQF(4) to be achieved. Reaction of LiI with TCNQF(4), in a 4:1 molar ratio, in boiling acetonitrile yields Li(2)TCNQF(4). However, deviation from this ratio or the reaction temperature gives either LiTCNQF(4) or a mixture of Li(2)TCNQF(4) and LiTCNQF(4). This is the first report of the large-scale chemical synthesis of Li(2)TCNQF(4). Attempts to prepare a single crystal of Li(2)TCNQF(4) have been unsuccessful, although air-stable (Pr(4)N)(2)TCNQF(4) was obtained by mixing Pr(4)NBr with Li(2)TCNQF(4) in aqueous solution. Pr(4)NTCNQF(4) was also obtained by reaction of LiTCNQF(4) with Pr(4)NBr in water. Li(2)TCNQF(4), (Pr(4)N)(2)TCNQF(4), and Pr(4)NTCNQF(4) have been characterized by UV-vis, FT-IR, Raman, and NMR spectroscopy, high resolution electrospray ionization mass spectrometry, and electrochemistry. The structures of single crystals of (Pr(4)N)(2)TCNQF(4) and Pr(4)NTCNQF(4) have been determined by X-ray crystallography. These TCNQF(4)(2-) salts will provide useful precursors for the synthesis of derivatives of the dianions. PMID:23153174

  16. Enhanced expression of PD-L1 in oral squamous cell carcinoma-derived CD11b(+)Gr-1(+) cells and its contribution to immunosuppressive activity.

    PubMed

    Fuse, Hiroki; Tomihara, Kei; Heshiki, Wataru; Yamazaki, Manabu; Akyu-Takei, Rie; Tachinami, Hidetake; Furukawa, Ken-Ichiro; Sakurai, Kotaro; Rouwan, Moniruzzaman; Noguchi, Makoto

    2016-08-01

    Cancer is often associated with dysregulation of both the humoral and cellular immune response, which in some instances is believed to result from changes in immune cell populations. For example, immunosuppressive CD11b(+)Gr-1(+) myeloid-derived suppressor cells have been shown to proliferate in the tumor microenvironment and surrounding tissues, highlighting the relationship between tumor growth and impairment of the immune response. However, the role of myeloid-derived suppressor cells in cancer progression has not been fully characterized because these cells are heterogeneous with properties influenced by the type and location of the tumor. Here, we show that CD11b(+)Gr-1(+) cells are elevated in the peripheral blood, spleen, and tumor of mice with oral squamous cell carcinoma. The phenotype and function of these cells varied depending on the tissue of origin. In particular, CD11b(+)Gr-1(+) cells in tumors expressed PD-L1 more abundantly than those in other tissues. Accordingly, CD11b(+)Gr-1(+) cells from tumors, but not from the spleen, suppressed T cell proliferation in vitro. The results suggest that tumor-derived or immune factors result in the accumulation of phenotypically and functionally diverse populations of CD11b(+)Gr-1(+) cells in mice with oral squamous cell carcinoma. The data also indicate that PD-L1 expression in CD11b(+)Gr-1(+) cells contributes to immune suppression, implying that targeting both myeloid-derived suppressor cells and PD-L1 would be an effective immunotherapeutic strategy against oral cancer.

  17. Lactobacillus rhamnosus GR-1 Ameliorates Escherichia coli-Induced Inflammation and Cell Damage via Attenuation of ASC-Independent NLRP3 Inflammasome Activation.

    PubMed

    Wu, Qiong; Liu, Ming-Chao; Yang, Jun; Wang, Jiu-Feng; Zhu, Yao-Hong

    2016-02-01

    Escherichia coli is a major environmental pathogen causing bovine mastitis, which leads to mammary tissue damage and cell death. We explored the effects of the probiotic Lactobacillus rhamnosus GR-1 on ameliorating E. coli-induced inflammation and cell damage in primary bovine mammary epithelial cells (BMECs). Increased Toll-like receptor 4 (TLR4), NOD1, and NOD2 mRNA expression was observed following E. coli challenge, but this increase was attenuated by L. rhamnosus GR-1 pretreatment. Immunofluorescence and Western blot analyses revealed that L. rhamnosus GR-1 pretreatment decreased the E. coli-induced increases in the expression of the NOD-like receptor family member pyrin domain-containing protein 3 (NLRP3) and the serine protease caspase 1. However, expression of the adaptor protein apoptosis-associated speck-like protein (ASC, encoded by the Pycard gene) was decreased during E. coli infection, even with L. rhamnosus GR-1 pretreatment. Pretreatment with L. rhamnosus GR-1 counteracted the E. coli-induced increases in interleukin-1β (IL-1β), -6, -8, and -18 and tumor necrosis factor alpha mRNA expression but upregulated IL-10 mRNA expression. Our data indicate that L. rhamnosus GR-1 reduces the adhesion of E. coli to BMECs, subsequently ameliorating E. coli-induced disruption of cellular morphology and ultrastructure and limiting detrimental inflammatory responses, partly via promoting TLR2 and NOD1 synergism and attenuating ASC-independent NLRP3 inflammasome activation. Although the residual pathogenic activity of L. rhamnosus, the dosage regimen, and the means of probiotic supplementation in cattle remain undefined, our data enhance our understanding of the mechanism of action of this candidate probiotic, allowing for development of specific probiotic-based therapies and strategies for preventing pathogenic infection of the bovine mammary gland. PMID:26655757

  18. Lactobacillus rhamnosus GR-1 Ameliorates Escherichia coli-Induced Inflammation and Cell Damage via Attenuation of ASC-Independent NLRP3 Inflammasome Activation

    PubMed Central

    Wu, Qiong; Liu, Ming-Chao; Yang, Jun; Wang, Jiu-Feng

    2015-01-01

    Escherichia coli is a major environmental pathogen causing bovine mastitis, which leads to mammary tissue damage and cell death. We explored the effects of the probiotic Lactobacillus rhamnosus GR-1 on ameliorating E. coli-induced inflammation and cell damage in primary bovine mammary epithelial cells (BMECs). Increased Toll-like receptor 4 (TLR4), NOD1, and NOD2 mRNA expression was observed following E. coli challenge, but this increase was attenuated by L. rhamnosus GR-1 pretreatment. Immunofluorescence and Western blot analyses revealed that L. rhamnosus GR-1 pretreatment decreased the E. coli-induced increases in the expression of the NOD-like receptor family member pyrin domain-containing protein 3 (NLRP3) and the serine protease caspase 1. However, expression of the adaptor protein apoptosis-associated speck-like protein (ASC, encoded by the Pycard gene) was decreased during E. coli infection, even with L. rhamnosus GR-1 pretreatment. Pretreatment with L. rhamnosus GR-1 counteracted the E. coli-induced increases in interleukin-1β (IL-1β), -6, -8, and -18 and tumor necrosis factor alpha mRNA expression but upregulated IL-10 mRNA expression. Our data indicate that L. rhamnosus GR-1 reduces the adhesion of E. coli to BMECs, subsequently ameliorating E. coli-induced disruption of cellular morphology and ultrastructure and limiting detrimental inflammatory responses, partly via promoting TLR2 and NOD1 synergism and attenuating ASC-independent NLRP3 inflammasome activation. Although the residual pathogenic activity of L. rhamnosus, the dosage regimen, and the means of probiotic supplementation in cattle remain undefined, our data enhance our understanding of the mechanism of action of this candidate probiotic, allowing for development of specific probiotic-based therapies and strategies for preventing pathogenic infection of the bovine mammary gland. PMID:26655757

  19. Expression of the fructose receptor BmGr9 and its involvement in the promotion of feeding, suggested by its co-expression with neuropeptide F1 in Bombyx mori.

    PubMed

    Mang, Dingze; Shu, Min; Tanaka, Shiho; Nagata, Shinji; Takada, Tomoyuki; Endo, Haruka; Kikuta, Shingo; Tabunoki, Hiroko; Iwabuchi, Kikuo; Sato, Ryoichi

    2016-08-01

    Insect gustatory receptors (Grs) are members of a large family of proteins with seven transmembrane domains that provide insects with the ability to detect chemical signals critical for feeding, mating, and oviposition. To date, 69 Bombyx mori Grs (BmGrs) genes have been identified via genome studies. BmGr9 has been shown to respond specifically to fructose and to function as a ligand-gated ion channel selectively activated by fructose. However, the sites where this Gr are expressed remain unclear. We demonstrated using reverse transcription (RT)-PCR that BmGr9 is widely expressed in the central nervous system (CNS), as well as oral sensory organs. Additionally, immunohistochemistry was performed using anti-BmGr9 antiserum to show that BmGr9 is expressed in cells of the oral sensory organs, including the maxillary galea, maxillary palps, labrum, and labium, as well as in putative neurosecretory cells of the CNS. Furthermore, double immunohistochemical analysis showed that most BmGr9-expressing cells co-localized with putative neuropeptide F1-expressing cells in the brain, suggesting that BmGr9 is involved in the promotion of feeding behaviors. In addition, a portion of BmGr9-expressing cells in the brain co-localized with cells expressing BmGr6, a molecule of the sugar receptor clade, suggesting that sugars other than fructose are involved in the regulation of feeding behaviors in B. mori larvae. PMID:27288056

  20. Effect of gamma-irradiated sludge on the growth and yield of rice (Oryza sativa L. var. GR-3).

    PubMed

    Pandya, G A; Prakash, L; Devasia, P; Modi, V V

    1988-01-01

    The effects of gamma-irradiated sludge on the growth and yield of rice (Oryza sativa L. var. GR-3) in pot cultures have been studied. Compared to plants grown only in soil, shoot length, root length, fresh weight, dry weight, total proteins, total soluble sugars, starch and chlorophyll content of plants grown in soil supplemented with unirradiated or gamma-irradiated sludge were found to be significantly increased. Irradiation of sludge significantly stimulated the linear growth of shoot and root systems as well as fresh and dry weights of plants, compared to those grown in soil containing unirradiated sludge. There was also an improvement in the grain yield (weight of seed) when plants were grown in soil supplemented with irradiated sludge. The results obtained suggest that the gamma-irradiated sewage sludge can be beneficially recycled for agricultural uses.

  1. Mapping and classification of geoforms in the Serra de Grândola (Alentejo, South West, Portugal)

    NASA Astrophysics Data System (ADS)

    Neto Paixão, Helena M.; Granja Martins, Fernando M.; Zavala, Lorena M.; Jordán, Antonio; Pereira, Paulo

    2013-04-01

    The study of geomorphic processes is the starting point for development and sustainable land management. These processes may cause risks that represent threats to environment, population and human activities. So, studying its genesis is important to find tools that can mitigate threats. In the last few decades, geographic information systems (GIS) have become an essential tool for environmental management. The integration of digital terrain models in GIS has contributed to improve environmental studies and knowledge, as they are a support for modelling geoforms (terrain units resulting from climate and other natural processes and their interactions with the Earth's surface). In this research, geoforms from the Serra de Grândola area (Alentejo, South West, Portugal) are classified according to the most important physical and structural differences. The methodology is based on the Hammond's hierarchical criteria and in the geographical information related to soft-slopes, local relief and terrain profiles.

  2. Volvulus grêlique sur hydatidose péritonéale: une cause rare d'occlusion

    PubMed Central

    Bouassria, Abdesslam; Mazine, Khalid; Elbouhaddouti, Hicham; Mouaqit, Ouadii; Ousadden, Abdelmalek; Mazaz, Khalid; Benjelloun, Elbachir; Taleb, Khalid Ait

    2014-01-01

    L'hydatidose péritonéale peut être primitive, hématogène ou hétérotopique, comme elle peut être secondaire et résulte de la fissuration d'un kyste hydatique, le plus souvent hépatique. Cliniquement polymorphe, elle peut se révéler par des douleurs abdominales ou par la palpation d'une masse abdominale. Nous rapportons le cas d'une patiente chez qui l'hydatidose péritonéale était révélée par un accident occlusif: un volvulus grêlique dû à un volumineux kyste hydatique mésentérique. Le traitement de l'hydatidose péritonéale est chirurgical, couplé à un traitement médical à base d'albendazole. PMID:25400846

  3. About accuracy increase of fractional order derivative and integral computations by applying the Grünwald-Letnikov formula

    NASA Astrophysics Data System (ADS)

    Brzeziński, Dariusz W.; Ostalczyk, Piotr

    2016-11-01

    The aim of the paper is to gather and to survey various formulas for fractional order derivative and integral calculations according to their Grünwald-Letnikov definition. The paper presents evaluation results for some factors, which influence its accuracy and efficiency of computations: different formulas for the coefficients calculations, different forms of the formula and different schemas for the function discretization, including more points per step of summation. It also hints how to solve some of the serious programming issues when applying the formulas. The objective is to determine a recipe for the increase the default low computational accuracy and efficiency of this popular method of fractional order derivative and integral calculations.

  4. Rapid release of metal salts and nutrients from the 2011 Grímsvötn, Iceland volcanic ash

    NASA Astrophysics Data System (ADS)

    Olsson, J.; Stipp, S. L. S.; Dalby, K. N.; Gislason, S. R.

    2013-12-01

    On May 21st, 2011, one of Iceland’s most active volcano, Grímsvötn, started its strongest eruption in a century. Grímsvötn produced hundreds of megatonnes of fine basaltic ash, which spread over Iceland, the North Atlantic and Europe. Such fine grained ash can impact human activity and health both with fertilization and with toxicity potential for aquatic environments. The purpose of this study was: (1) to investigate the basic physical and chemical properties of the ash from the 2011 Grímsvötn eruption, (2) to identify surface salts deposited on the ash during the eruption, (3) to identify which elements are released during ash-water interactions and their release rates, (4) to characterize the secondary phases formed during water exposure, and (5) to assess impact of the ash on humans and the environment. During the eruption, we collected a unique set of pristine ash samples over a range of 50-115 km from the source and examined them with X-ray powder diffraction (XRPD), X-ray fluorescence (XRF), surface area analysis (BET), laser absorption, electron microprobe (EMPA), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The ash could be classified as glassy tholeiitic basalt with <10 mass% crystalline plagioclase (Al1.6Ca0.6Na0.4Si2.4O8) and pyroxene. The particles were small (<125 μm) and elongated with sharp edges. About 50% of the particle mass was fine ash (<63 μm), which could travel long distances, and ∼8% was very fine ash (<10 μm), which is harmful if inhaled. The specific surface area of the pristine ash ranged from 0.4 to 0.7 m2/g. Material taken up on particle surfaces contributed the equivalent of <0.5 nm thick layer, consisting of salts such as CaSO4, Na2SO4, NaCl, CaF2, CaCl2, MgSO4 and MgCl2. We exposed the pristine ash to ultrapure deionised (MilliQ) water in a single pass, plug, flow through reactor and the effluent was analyzed for 73 elements using inductively coupled plasma sector field mass

  5. On the volume-dependence of the Grüneisen parameter and the Lindemann law of melting

    NASA Astrophysics Data System (ADS)

    Kushwah, S. S.; Tomar, Y. S.; Upadhyay, A. K.

    2013-08-01

    It has been shown by Errandonea (Physica B 357 (2005) 356) that the Lindemann law cannot reproduce the high pressure melting curves of transition metals. Using an expression for the volume dependence of the Grüneisen parameter γ originally due to Burakovsky and Preston (J. Phys. Chem. Solids 65 (2004) 1581), Errandonea determined the constants appearing in the expression of gamma by making the Lindemann law to match the experimental melting data. The results for the volume dependence of gamma thus obtained by Errandonea are shown here to be much different from those determined using the Burakovsky-Preston approach. A direct comparison of the results based on the two approaches has been presented for the transition metal Mo. It is reinforced that the Lindemann law does not work satisfactorily for the transition metals with low slopes of melting curves.

  6. Experimental determination of Grüneisen gamma for polyether ether ketone (PEEK) using the shock-reverberation technique

    NASA Astrophysics Data System (ADS)

    Roberts, Andrew; Appleby-Thomas, Gareth James; Hazell, Paul

    2012-03-01

    Following multiple loading events the resultant shock state of a material will lie away from the principle Hugoniot. Prediction of such states requires knowledge of a materials equation-of-state. The material-specific variable Grüneisen gamma, γ(v), defines the shape of "off-Hugoniot" points in energy-volume-pressure space. Here, the shock response of the important temperature-resistant polymer polyether ether ketone (PEEK) was compared to ANSYS Autodyn® simulations in an attempt to estimate a value of γ1. However, inconsistencies between experimental and computational results were found, highlighting the importance of full knowledge of material properties for such analyses. In particular, this approach led to revision of the established equation-of-state for PEEK, with a new nonlinear form identified.

  7. Glucocorticoid-induced tethered transrepression requires SUMOylation of GR and formation of a SUMO-SMRT/NCoR1-HDAC3 repressing complex

    PubMed Central

    Hua, Guoqiang; Ganti, Krishna Priya; Chambon, Pierre

    2016-01-01

    Upon binding of a glucocorticoid (GC), the GC receptor (GR) can exert one of three transcriptional regulatory functions. We recently reported that SUMOylation of the GR at position K293 in humans (K310 in mice) within the N-terminal domain is indispensable for GC-induced evolutionary conserved inverted repeated negative GC response element (IR nGRE)-mediated direct transrepression. We now demonstrate that the integrity of this GR SUMOylation site is mandatory for the formation of a GR-small ubiquitin-related modifiers (SUMOs)-SMRT/NCoR1-HDAC3 repressing complex, which is indispensable for NF-κB/AP1-mediated GC-induced tethered indirect transrepression in vitro. Using GR K310R mutant mice or mice containing the N-terminal truncated GR isoform GRα-D3 lacking the K310 SUMOylation site, revealed a more severe skin inflammation than in WT mice. Importantly, cotreatment with dexamethasone (Dex) could not efficiently suppress a 12-O-tetradecanoylphorbol-13-acetate (TPA)–induced skin inflammation in these mutant mice, whereas it was clearly decreased in WT mice. In addition, in mice selectively ablated in skin keratinocytes for either nuclear receptor corepressor 1 (NCoR1)/silencing mediator for retinoid or thyroid-hormone receptors (SMRT) corepressors or histone deacetylase 3 (HDAC3), Dex-induced tethered transrepression and the formation of a repressing complex on DNA-bound NF-κB/AP1 were impaired. We previously suggested that GR ligands that would lack both (+)GRE-mediated transactivation and IR nGRE-mediated direct transrepression activities of GCs may preferentially exert the therapeutically beneficial GC antiinflammatory properties. Interestingly, we now identified a nonsteroidal antiinflammatory selective GR agonist (SEGRA) that selectively lacks both Dex-induced (+)GRE-mediated transactivation and IR nGRE-mediated direct transrepression functions, while still exerting a tethered indirect transrepression activity and could therefore be clinically lesser

  8. The 5-HT3 receptor antagonists ICS 205-930 and GR38032F, putative anxiolytic drugs, differ from diazepam in their pharmacological profile.

    PubMed

    Papp, M; Przegalinski, E

    1989-01-01

    The pharmacological profile of the two 5-HT(3) (5-hydroxytryptamine) receptor antagonists, the putative anxiolytics ICS 205-930 and GR38032F was compared with that of diazepam in four standard behavioural tests in rats. All the investigated drugs induced an anxiolytic effect in the passive avoidance test, having reduced the latency to re-enter the chamber previously associated with an inescapable footshock, and increased the time spent in that chamber. On the basis of the lowest effective dose, both ICS 205-930 and GR38032F were about 20 times more potent than diazepam, though the anxiolytic activity of either 5- HT(3) receptor antagonist was confined to a narrow dose range (ICS 205-930: 93.7-187.5 μg/ kg, GR38032F: 125-375 μg/kg), their higher doses having been ineffective. The anxiolytic effect of diazepam, but not of ICS 205-930, was abolished by flumazenil. In contrast to diazepam, neither ICS 205-930 nor GR38032F-both given in doses up to 20 mg/kg-showed any activity in the pentylenetetrazol-induced seizures, open field, and rota-rod tests. These results suggest that the 5-HT(3) receptor antagonists may represent a new class of anxiolytic drugs devoid of anticonvulsant, sedative or muscle-relaxant properties, and that their anxi olytic activity is not mediated by benzodiazepine receptors.

  9. Effects of artificial sweeteners on the AhR- and GR-dependent CYP1A1 expression in primary human hepatocytes and human cancer cells.

    PubMed

    Kamenickova, Alzbeta; Pecova, Michaela; Bachleda, Petr; Dvorak, Zdenek

    2013-12-01

    Food constituents may cause a phenomenon of food-drug interactions. In the current study, we examined the effects of artificial sweeteners (aspartame, acesulfame, cyclamate, saccharin) on the aryl hydrocarbon receptor (AhR) and glucocorticoid receptor (GR)-dependent expression of CYP1A1 in human hepatocytes, hepatic HepG2 and intestinal LS174T cancer cell lines. Sweeteners were tested in concentrations up to those occurring in non-alcoholic beverages. Basal and ligand-inducible AhR- and GR-dependent reporter gene activation in stably transfected HepG2 and HeLa cells, respectively, were not affected by either of the sweeteners tested after 24h of incubation. The expression of CYP1A1 mRNA and protein in primary cultures of human hepatocytes and in LS174T and HepG2 cells was not induced by any of the tested sweeteners. Overall, aspartame, acesulfame, saccharin and cyclamate had no effects on CYP1A1 expression and transcriptional activities of AhR and GR. These data imply the safety of artificial sweeteners in terms of interference with AhR, GR and CYP1A1.

  10. Ethanol fails to modify [3H]GR65630 binding to 5-HT3 receptors in NCB-20 cells and in rat cerebral membranes.

    PubMed

    Hellevuo, K; Hoffman, P L; Tabakoff, B

    1991-10-01

    Low concentrations of ethanol have been found to enhance the electrophysiologic effect of serotonin (5-HT) acting at 5-HT3 receptors on NCB-20 cells. To determine whether this action of ethanol reflects a change in the agonist-receptor interaction, the effect of ethanol (100 mM) on agonist and antagonist binding to 5-HT3 receptor was studied in vitro in membrane from NCB-20 cells and from cortex plus hippocampus of rat. The antagonist [3H]GR65630 was used to label 5-HT3 recognition sites. Ethanol did not change the characteristics of saturable [3H]GR65630 binding in either membrane preparation. In competition studies, the agonists 5-HT and 2-methyl-5-HT completely inhibited the binding of [3H]GR65630 to NCB-20 cell membranes, while in brain membranes the maximum displacement of specific [3H]GR65630 binding by 5-HT was approximately 30%. Ethanol decreased the affinity of the receptor for 2-methyl-5-HT, but not to 5-HT in NCB-20 cells, and had no effect on agonist binding in brain membranes. The results indicate that enhancement of 5-HT responses at 5-HT3 receptors by ethanol is not a result of changes in the equilibrium binding characteristics of the agonist.

  11. Elevated utero/placental GR/NR3C1 is not required for the induction of parturition in the dog.

    PubMed

    Gram, Aykut; Trachsel, Alexandra; Boos, Alois; Kowalewski, Mariusz P

    2016-10-01

    The endocrine mechanisms that lead to initiation of parturition in dogs are still not fully understood. The prepartum luteolysis is associated with increased prostaglandin (PG) F2α secretion; however, there is no pregnancy- or parturition-related increase in estrogens. Moreover, unlike in other mammalian species, in the dog, increased peripartum levels of cortisol measured sporadically in maternal peripheral blood are not mandatory for normal parturition. Nevertheless, auto/paracrine effects of cortisol at the placental feto-maternal level cannot be excluded. Therefore, the aim of this study was to investigate the expression and localization of glucocorticoid receptor (GR/NR3C1) in canine utero/placental (Ut/Pl) units and uterine interplacental sites at selected time points during pregnancy (pre-implantation, post-implantation and mid-gestation), and at normal and antigestagen-induced parturition. The Ut/Pl expression of GR/NR3C1 did not change significantly from pre-implantation until mid-gestation; however, it was strongly induced during the prepartum luteolysis. Within the interplacental samples, expression of GR/NR3C1-mRNA was greater post-implantation than pre-implantation and did not change afterward, i.e. toward mid-gestation. Compartmentalization studies within the Ut/Pl units, involving placenta, endometrium and myometrium separately, performed at the prepartum luteolysis revealed the highest GR/NR3C1-mRNA levels in placenta compared with endometrium and myometrium. Interestingly, in antigestagen-treated mid-pregnancy dogs, Ut/Pl and interplacental GR/NR3C1-mRNA expression remained unaffected. At the cellular level, placental GR/NR3C1 was clearly detectable in placenta fetalis, i.e. in trophoblast cells. In conclusion, increased expression of GR/NR3C1 during normal parturition, but not following antigestagen-treatment, suggest that it is not required for initiating the signaling cascade of PG synthesis leading to the induction of parturition in the dog

  12. Epitaxial V{sub 0.6}W{sub 0.4}N/MgO(001): Evidence for ordering on the cation sublattice

    SciTech Connect

    Kindlund, H.; Lu, J.; Jensen, J.; Hultman, L.; Petrov, I.; Greene, J. E.

    2013-07-15

    V{sub 0.6}W{sub 0.4}N alloys are grown on MgO(001) by ultrahigh vacuum reactive magnetron sputtering from V and W targets in 10 mTorr pure-N{sub 2} atmospheres at temperatures T{sub s} ranging from 600 to 900 Degree-Sign C. Based on x-ray diffraction and transmission electron microscopy results, all films have the B1-NaCl crystal structure and grow with a cube-on-cube epitaxial relationship to the substrate, (001){sub VWN} Double-Vertical-Line (001){sub MgO} and [100]{sub VWN} Double-Vertical-Line [100]{sub MgO}. Rutherford backscattering spectrometry analyses show that the N content in V{sub 0.6}W{sub 0.4}N{sub x} alloys decreases with increasing T{sub s} from overstoichiometric with x = 1.13 at 600 Degree-Sign C, to approximately stoichiometric with x = 1.08 at 700 Degree-Sign C, to understoichiometric at 800 Degree-Sign C (x = 0.80) and 900 Degree-Sign C (x = 0.75). High-resolution scanning transmission electron microscopy, Z-contrast, and selected-area electron diffraction investigations of V{sub 0.6}W{sub 0.4}N(001) alloys grown at 600 and 700 Degree-Sign C reveal the onset of W ordering on adjacent 111 planes of the metal sublattice; no ordering is observed for understoichiometric films grown at higher temperatures.

  13. An Altered Immune Response, but Not Individual Cationic Antimicrobial Peptides, Is Associated with the Oral Attenuation of Ara4N-Deficient Salmonella enterica Serovar Typhimurium in Mice

    PubMed Central

    Tamayo, Rita; Reeves, Linh T.; Gunn, John S.

    2012-01-01

    Salmonella enterica serovar Typhimurium (S. Typhimurium) uses two-component regulatory systems (TCRS) to respond to stimuli in the local microenvironment. Upon infection, the Salmonella TCRSs PhoP-PhoQ (PhoPQ) and PmrA-PmrB (PmrAB) are activated by environmental signals in the intestinal lumen and within host cells. TCRS-mediated gene expression results in lipopolysaccharide (LPS) modification and cationic antimicrobial peptide resistance. The PmrA-regulated pmrHFIJKLM operon mediates 4-amino-4-deoxy-L-arabinose (Ara4N) production and attachment to the lipid A of LPS. A ΔpmrF S. Typhimurium strain cannot produce Ara4N, exhibits increased sensitivity to cationic antimicrobial peptide (CAMP)-mediated killing, and attenuated virulence in mice upon oral infection. CAMPs are predicted to play a role in elimination of Salmonella, and may activate PhoPQ and PmrAB in vivo, which could increase bacterial resistance to host defenses. Competition experiments between wild type (WT) and ΔpmrF mutant strains of S. Typhimurium indicated that selection against this mutant first occurs within the intestinal lumen early during infection. However, CRAMP and active cryptdins alone are not responsible for elimination of Ara4N-deficient bacteria in vivo. Investigation into the early immune response to ΔpmrF showed that it differed slightly from the early immune response to WT S. Typhimurium. Further investigation into the early immune response to infection of Peyer’s patches suggests a role for IL-13 in the attenution of the ΔpmrF mutant strain. Thus, prominent CAMPs present in the mouse intestine are not responsible for the selection against the ΔpmrF strain in this location, but limited alterations in innate immune induction were observed that affect bacterial survival and virulence. PMID:23166721

  14. A comparative in vitro and in vivo pharmacological characterization of the novel dopamine D3 receptor antagonists (+)-S 14297, nafadotride, GR 103,691 and U 99194.

    PubMed

    Audinot, V; Newman-Tancredi, A; Gobert, A; Rivet, J M; Brocco, M; Lejeune, F; Gluck, L; Desposte, I; Bervoets, K; Dekeyne, A; Millan, M J

    1998-10-01

    The benzofurane (+)-S 14297, the benzamide nafadotride, the aminoindane U 99194 and the arylpiperazine GR 103,691 have been proposed as "selective" antagonists at dopamine D3 vs. D2 receptors. Herein, we compared their in vitro affinities and in vivo actions to those of the aminotetralin D3 antagonists (+)-AJ 76 and (+)-UH 232. Affinities at recombinant, human (h)D3 and/or hD2 sites were determined by employing the mixed D2/D3 antagonist [125I]-iodosulpride and the preferential D3 ligands [3H]-(+)-PD 128, 907 and [3H]-(+)-S 14297. [3H]-(+)-PD 128,907, [3H]-(+)-S 14297 and [125I]-iodosulpride yielded an essentially identical pattern of displacement at D3 sites, which suggests that they recognize the same population of receptors. The rank order of potency (Ki values in nM vs. [3H]-(+)-PD 128,907) was GR 103,691 (0.4) approximately nafadotride (0.5) > haloperidol (2) approximately (+)-UH 232 (3) approximately (+)-S 14297 (5) > (+)-AJ 76 (26) > U 99194 (160). The rank order of preference (Ki ratio, D2:D3) for D3 receptors (labeled by [3H]-PD 128,907) vs. D2 sites (labeled by [125I]-iodosulpride) was (+)-S 14297 (61) approximately GR 103,691 (60) > U 99194 (14) > nafadotride (9) approximately (+)-UH 232 (8) approximately (+)-AJ 76 (6) > haloperidol (0.2). (+)-S 14297 and GR 103,691 also showed greater than 100-fold selectivity at dopamine hD3 vs. hD4 and hD1 sites. However, GR 103,691 showed marked affinity for serotonin1A receptors (5.8 nM) and alpha-1 adrenoceptors (12.6 nM). In vivo, all antagonists except GR 103,691 prevented the induction of hypothermia by (+)-PD 128,907 (0.63 mg/kg s.c.) and a further preferential D3 agonist, (+)-7-OH-DPAT (0.16 mg/kg s.c.). On the other hand, haloperidol, (+)-AJ 76, (+)-UH 232 and nafadotride all induced catalepsy in rats, whereas (+)-S 14297, U 99194 and GR 103,691 were inactive. Haloperidol, (+)-AJ 76, (+)-UH 232, nafadotride and (weakly) U 99194 also enhanced prolactin secretion and striatal dopamine synthesis, whereas (+)-S

  15. Spectral detectability of CH4-N2 clathrates for in-situ and remote observation of Titan and other icy moons

    NASA Astrophysics Data System (ADS)

    Nna-Mvondo, D.; Tobie, G.; Le Menn, E.; Grasset, O.

    2015-10-01

    Multicomponent clathrates may be present at the surface of several icy moons, although they have not been detected yet, possibly due to the absence of reliable spectral data. In this work, w e present infrared (IR) and Raman spectral studies of CH4-N2 clathrates at low temperature and pressure, in order to identify discriminating criteria for their possible detection. These clathrates are particularly interesting for Titan and Pluto. Our experimental results indicate that identification of mixed clathrate from remote sensing is very challenging, and that only in- situ Raman spectroscopy may provide a clear identification of clathrate and co nstraints on their composition.

  16. Absorption intensities and complex refractive indices of crystalline HCN, HC3N, and C4N2 in the infrared region

    NASA Technical Reports Server (NTRS)

    Masterson, C. M.; Khanna, R. K.

    1990-01-01

    IR absorption intensities are presented for thin crystalline films of HCN, HC3N, and C4N2, together with n and k complex refractive indices determined on the basis of an iterative program for the Kramers-Konig integral via a least-squares, point-by-point fitting of the experimental transmission data. It is established that the transmission spectra generated by means of these n and k values can reproduce the experimental transmission observation values to within + or - 2 percent.

  17. Second hyperpolarizability of the calcium-doped lithium salt of pyridazine Li-H3C4N2 ⋯ Ca

    NASA Astrophysics Data System (ADS)

    Marques, Suélio; Castro, Marcos A.; Leão, Salviano A.; Fonseca, Tertius L.

    2016-08-01

    In this work we report results of coupled cluster calculations for the second hyperpolarizability of the calcium-doped lithium salt of pyridazine (Li-H3C4N2 ⋯ Ca) molecule. In the static limit an unusual value of 4.34 ×106 au was obtained at the CCSD level of calculation. Results obtained for the dc-Kerr effect through SCF, CCS and CCSD methods show that γ (- ω; ω, 0, 0) is strongly dependent of the electron correlation treatment. Dynamic results obtained at the CCSD level are also reported for the IDRI, dc-SHG and THG nonlinear optical processes.

  18. Synthesis, spectral characteristics, and the crystal and molecular structures of 2,3-dimethyl-1-phenyl-4-(N-phthalimido)pyrazolone-5

    SciTech Connect

    Sokol, V. I.; Strashnova, S. B. Kovalchukova, O. V.; Sergienko, V. S.; Davydov, V. V.; Zaitsev, B. E.; Evtushenko, Yu. M.

    2008-11-15

    2,3-Dimethyl-1-phenyl-4-(N-phthalimido)pyrazolone-5 (I) is synthesized and isolated in the form of single crystals. The crystal structure of compound I is determined using X-ray diffraction. The phthalimide and pyrazolone rings in the molecule are not coplanar: the angle between their median planes is 56.4{sup o}. The bond lengths in the rings level off, which indicates the delocalization of the electron density. The spectral characteristics (IR and electronic spectra) of molecule I are determined.

  19. meso-(4-(N,N-dialkylamino)phenyl)-substituted subporphyrins: remarkably perturbed absorption spectra and enhanced fluorescence by intramolecular charge transfer interactions.

    PubMed

    Inokuma, Yasuhide; Easwaramoorthi, Shanmugam; Yoon, Zin Seok; Kim, Dongho; Osuka, Atsuhiro

    2008-09-17

    A series of meso-(4-(N,N-dibenzylamino)phenyl)-substituted subporphyrins was synthesized by means of Buchwald-Hartwig amination protocol. Substitution of the amino group at the 4-position of the meso-phenyl substituent resulted in a remarkable red shift in the absorption spectra and drastic enhancement of fluorescence intensity probably as a consequence of intramolecular CT interaction. These characteristics have been utilized to construct a cation-sensing system by appending a 1-aza-15-crown-5 unit to subporphyrin that displays large spectral changes upon cation binding.

  20. Reflection seismic characterization of the Grängesberg iron deposit and its mining-induced structures, central Sweden

    NASA Astrophysics Data System (ADS)

    Place, Joachim; Malehmir, Alireza; Högdahl, Karin; Juhlin, Christopher; Persson Nilsson, Katarina

    2014-05-01

    Reflection seismic investigation has been conducted on the Grängesberg apatite iron deposit where over 150 Mt of iron ore were produced until the mine closed in 1989. The mine infrastructure with shafts and tunnels extend down to ca. 650 m below the surface. Both natural and mine induced fracture and fault systems are today water-filled (some of them extending to the surface). The disputed ore genesis of the apatite-iron ores and its exploration potential due to large remaining quantities once again attracts both scientific and commercial interests. A good understanding of the geometry of mineral deposits and their hostrock structures at depth is essential for optimizing their exploration and exploitation. In addition, deep understanding of the fracture system is vital if mining activity is resumed as these may impact the terrain stability and seismicity, which may put at risk new populated and industrial areas. To address some of these challenging issues related to the past mining and also to obtain information about the depth continuation of the existing deposit, two E-W oriented reflection lines with a total length of 3.5 km were acquired in May 2013 by Uppsala University. A weight drop mounted on an hydraulic bobcat truck (traditionally used for concrete breaking in demolition sector) was used to generate seismic signal. In order to increase the signal-to-noise ratio, several impacts were generated at each shot point and stacked together. The seismic lines intersect at high angle the Grängesberg ore body and open pit, as well as several mining-induced faults. A combination of cabled and wireless receivers placed at every 10 m was used for the data recording. Use of wireless receivers was necessary as deploying cabled sensors was not possible due to city infrastructures, roads and houses. A careful analysis of the data suggested that several field-related issues such as (1) the crooked geometry of the lines (due to the available path and road network), (2

  1. A study of planar Richtmyer-Meshkov instability in fluids with Mie-Grüneisen equations of state

    NASA Astrophysics Data System (ADS)

    Ward, G. M.; Pullin, D. I.

    2011-07-01

    We present a numerical comparison study of planar Richtmyer-Meshkov instability with the intention of exposing the role of the equation of state. Results for Richtmyer-Meshkov instability in fluids with Mie-Grüneisen equations of state derived from a linear shock-particle speed Hugoniot relationship (Jeanloz, J. Geophys. Res. 94, 5873, 1989; McQueen et al., High Velocity Impact Phenomena (1970), pp. 294-417; Menikoff and Plohr, Rev. Mod. Phys. 61(1), 75 1989) are compared to those from perfect gases under nondimensionally matched initial conditions at room temperature and pressure. The study was performed using Caltech's Adaptive Mesh Refinement, Object-oriented C++ (AMROC) (Deiterding, Adaptive Mesh Refinement: Theory and Applications (2005), Vol. 41, pp. 361-372; Deiterding, "Parallel adaptive simulation of multi-dimensional detonation structures," Ph.D. thesis (Brandenburgische Technische Universität Cottbus, September 2003)) framework with a low-dissipation, hybrid, center-difference, limiter patch solver (Ward and Pullin, J. Comput. Phys. 229, 2999 (2010)). Results for single and triple mode planar Richtmyer-Meshkov instability when a reflected shock wave occurs are first examined for mid-ocean ridge basalt (MORB) and molybdenum modeled by Mie-Grüneisen equations of state. The single mode case is examined for incident shock Mach numbers of 1.5 and 2.5. The planar triple mode case is studied using a single incident Mach number of 2.5 with initial corrugation wavenumbers related by k1=k2+k3. Comparison is then drawn to Richtmyer-Meshkov instability in perfect gases with matched nondimensional pressure jump across the incident shock, post-shock Atwood ratio, post-shock amplitude-to-wavelength ratio, and time nondimensionalized by Richtmyer's linear growth time constant prediction. Differences in start-up time and growth rate oscillations are observed across equations of state. Growth rate oscillation frequency is seen to correlate directly to the oscillation

  2. Sulphide globules and their impact on sulphur degassing budget: the case of Grímsvötn volcano, Iceland.

    NASA Astrophysics Data System (ADS)

    Haddadi, Baptiste; Carn, Simon; Sigmarsson, Olgeir

    2014-05-01

    Volcanic eruptions are known to contribute sulphur to the atmosphere. Two different methods allow estimation of sulphur mass loading: remote satellite measurements and the petrologic method. Sulphur emission at subduction-related volcanoes is often underestimated by the latter method relative to the former whereas a fair agreement is found for hot spot-related volcanoes. The Grímsvötn 2011 eruption allows further comparison between these two methods. Grímsvötn is a basaltic subglacial volcano located under the Vatnajökull ice cap, above the Iceland mantle plume and the Mid-Atlantic Ridge. The May 2011 eruption lasted one week and took place inside the composite caldera of the volcano. During the first 24 hours, the column reached a height of more than 20 km and bulk of the magma was emitted. The basaltic tephra has quartz-normative tholeiite composition with 1-5% plagioclase, clinopyroxene, olivine, FeTi-oxide crystals and, noteworthy, sulphide globules present in the groundmass glass. Sulphur concentrations of twenty eight melt inclusions (MIs) were measured in plagioclase, clinopyroxene and olivine crystals extracted from the tephra produced during the most explosive phase. The difference between the mean sulphur content of both MIs and groundmass glass multiplied by the magma mass erupted, yields 0.73 ± 0.18 Tg of liberated sulphur. This is four times the estimated sulphur degassing by satellite measurements (0.19 ± 0.06 Tg). The contributions of different sulphur sinks were quantified. The geothermal system harvests approximately 0.037 Tg (5%), which are liberated during jökulhlaups. Sulphur adhering to the volcanic ash is approximately 0.12 Tg (15%). Added to the satellite measurements of sulphur entering the stratosphere, half of the S estimated by the petrologic method is still missing. Sulphur immiscibility forming sulphur globules in the magma chambers appears the most probable explanation for the missing 50% of sulphur. Due to elevated density of

  3. Assessing the viability of extended nonmetal atom chains in M(n)F(4n+2) (M=S and Se).

    PubMed

    Popov, Ivan A; Averkiev, Boris B; Starikova, Alyona A; Boldyrev, Alexander I; Minyaev, Ruslan M; Minkin, Vladimir I

    2015-01-26

    Theoretical investigations to evaluate the viability of extended nonmetal atom chains on the basis of molecular models with the general formula Mn F4n+2 (M=S and Se) and corresponding solid-state systems exhibiting direct SS or SeSe bonding were performed. The proposed high-symmetry molecules were found to be minima on the potential energy surface for all Sn F4n+2 systems studied (n=2-9) and for selenium analogues up to n=6. Phonon calculations of periodic structures confirmed the dynamic stability of the -(SF4 -SF4 )∞ - chain, whereas the analogous -(SeF4 -SeF4 )∞ - chain was found to have a number of imaginary phonon frequencies. Chemical bonding analysis of the dynamically stable -(SF4 -SF4 )∞ - structure revealed a multicenter character of the SS and SF bonds. A novel definition and abbreviation (ENAC) are proposed by analogy with extended metal atom chain (EMAC) complexes.

  4. Removal of ZnO nanoparticles in simulated wastewater treatment processes and its effects on COD and NH(4)(+)-N reduction.

    PubMed

    Hou, Linlin; Xia, Jing; Li, Kaiyang; Chen, Jian; Wu, Xiaolei; Li, Xiqing

    2013-01-01

    For many engineered nanoparticles, the primary pathway of release into the environment is via sewage and industrial wastewater discharges. In this work, the removal of uncoated ZnO nanoparticles (ZnO NPs) during simulated wastewater treatment processes and its impact on treatment performance were examined. Simulated primary clarification removed the majority (about 70%) of the dosed ZnO NPs. During simulated sequencing batch reactor (SBR) processes, ZnO NPs were completely removed in each cycle throughout the 11-day experimental duration (two cycles per day). Continuous input of ZnO NPs into the wastewater (at concentrations up to 5 mg L(-1)) did not reduce chemical oxygen demand (COD) removal. NH(4)(+)-N removal was reduced at a dosing concentration of 5 mg L(-1) ZnO NPs per cycle. Inhibition of respiration of nitrifying microorganisms by ZnO NPs corroborated the reduction of NH(4)(+)-N removal. These results indicate that if the wastewater is treated, the release of ZnO NPs into receiving water bodies would be minimal and ZnO NPs would mainly accumulate in biosolids. Uncoated ZnO NPs in wastewater at very high concentrations may have some adverse effects on activated sludge process. PMID:23168621

  5. Magnetism by interfacial hybridization and p-type doping of MoS(2) in Fe(4)N/MoS(2) superlattices: a first-principles study.

    PubMed

    Feng, Nan; Mi, Wenbo; Cheng, Yingchun; Guo, Zaibing; Schwingenschlögl, Udo; Bai, Haili

    2014-03-26

    Magnetic and electronic properties of Fe4N(111)/MoS2(√3 × √3) superlattices are investigated by first-principles calculations, considering two models: (I) Fe(I)Fe(II)-S and (II) N-S interfaces, each with six stacking configurations. In model I, strong interfacial hybridization between Fe(I)/Fe(II) and S results in magnetism of monolayer MoS2, with a magnetic moment of 0.33 μB for Mo located on top of Fe(I). For model II, no magnetism is induced due to weak N-S interfacial bonding, and the semiconducting nature of monolayer MoS2 is preserved. Charge transfer between MoS2 and N results in p-type MoS2 with Schottky barrier heights of 0.5-0.6 eV. Our results demonstrate that the interfacial geometry and hybridization can be used to tune the magnetism and doping in Fe4N(111)/MoS2(√3 × √3) superlattices.

  6. Pressure-driven variations of hydrogen bonding energy in ammonium azide (NH4N3): IR absorption and Raman scattering studies.

    PubMed

    Wu, Xiaoxin; Ma, Fengxian; Ma, Chunli; Cui, Hang; Liu, Zhenxian; Zhu, Hongyang; Wang, Xiaoli; Cui, Qiliang

    2014-07-14

    In this study, high pressure infrared (IR) absorption and Raman scattering studies for ammonium azide (NH4N3) were carried out at room temperature up to 20 GPa and 22 GPa, respectively. For comparison and further assignment, the vibrational spectra at ambient conditions were calculated using CASTEP code, particularly for the far- and mid-IR modes. The recorded vibrational data consistently indicated a pressure-induced phase transition at 2.9 GPa. All observed vibrational modes maintained their identities at the high pressure phase, indicating that NH4N3 was still presented in the form of ammonium cations and azide anions linked by the hydrogen bond (N-H⋯N). Above 2.9 GPa, the relative magnitude of the torsional mode weakened and the N-H symmetric stretch displayed a redshift, indicating strengthened hydrogen bonding energy. The opposite effects were observed above 12 GPa, where the relative magnitude of the torsional mode strengthened and the N-H symmetric stretch reverted to a blueshift, indicating weakened hydrogen bonding energy. It can be concluded that the hydrogen bonding energy exhibited a weakening (0-2.9 GPa), strengthening (2.9-12 GPa), and then again weakening (12-22 GPa) phenomena with the increasing of compression. The hydrogen bonding energy changing with the increase of pressure can be ascribed to a phase transition at 2.9 GPa and a rotational or bending behavior of azide ions at 12 GPa.

  7. Influence of bulking agents on CH4, N2O, and NH3 emissions during rapid composting of pig manure from the Chinese Ganqinfen system*

    PubMed Central

    Sun, Xiang-ping; Lu, Peng; Jiang, Tao; Schuchardt, Frank; Li, Guo-xue

    2014-01-01

    Mismanagement of the composting process can result in emissions of CH4, N2O, and NH3, which have caused severe environmental problems. This study was aimed at determining whether CH4, N2O, and NH3 emissions from composting are affected by bulking agents during rapid composting of pig manure from the Chinese Ganqinfen system. Three bulking agents, corn stalks, spent mushroom compost, and sawdust, were used in composting with pig manure in 60 L reactors with forced aeration for more than a month. Gas emissions were measured continuously, and detailed gas emission patterns were obtained. Concentrations of NH3 and N2O from the composting pig manure mixed with corn stalks or sawdust were higher than those from the spent mushroom compost treatment, especially the sawdust treatment, which had the highest total nitrogen loss among the three runs. Most of the nitrogen was lost in the form of NH3, which accounts for 11.16% to 35.69% of the initial nitrogen. One-way analysis of variance for NH3 emission showed no significant differences between the corn stalk and sawdust treatments, but a significant difference was noted between the spent mushroom compost and sawdust treatments. The introduction of sawdust reduced CH4 emission more than the corn stalks and spent mushroom compost. However, there were no significant differences among the three runs for total carbon loss. All treatments were matured after 30 d. PMID:24711356

  8. Inter-atomic potential energy and Grüneisen parameter: A new method for equation of state of solids

    NASA Astrophysics Data System (ADS)

    Parish, Peter G.; Moore, John

    2015-05-01

    This paper presents a rational foundation for the computation of equation of state (EOS) data for solids at high pressure. We demonstrate a new method which makes use of an accurate relation expressing the Grüneisen parameter γ (as a function of the specific volume V of the material) in terms of the specific inter-atomic potential energy ϕ (V). Existing expressions for γ in the literature are usually approximations in terms of total pressure P. There is a variety of such " (γ, P)" formulas and one needs experience in deciding which to use in any particular application. The alternative " (γ, ϕ)" relationship presented here is both unique and exact within the Debye and harmonic approximations and allows the individual terms of the EOS to be determined separately. It is rigorously derived in this paper and solved numerically, using experimental input data for aluminium, copper, lead and gold, to predict ϕ, dϕ / dV, γ, dγ / dV and EOS data for the four metals. Comparison is made with existing computations in the literature showing good agreement. The method can be applied to any metal or non-metal using experimental input data from any suitable volume-dependent locus.

  9. Integrating sphere-based photoacoustic setup for simultaneous absorption coefficient and Grüneisen parameter measurements of biomedical liquids

    NASA Astrophysics Data System (ADS)

    Villanueva, Yolanda; Hondebrink, Erwin; Petersen, Wilma; Steenbergen, Wiendelt

    2015-03-01

    A method for simultaneously measuring the absorption coefficient μa and Grüneisen parameter Γ of biological absorbers in photoacoustics is designed and implemented using a coupled-integrating sphere system. A soft transparent tube with inner diameter of 0.58mm is used to mount the liquid absorbing sample horizontally through the cavity of two similar and adjacent integrating spheres. One sphere is used for measuring the sample's μa using a continuous halogen light source and a spectrometer fiber coupled to the input and output ports, respectively. The other sphere is used for simultaneous photoacoustic measurement of the sample's Γ using an incident pulsed light with wavelength of 750nm and a flat transducer with central frequency of 5MHz. Absolute optical energy and pressure measurements are not necessary. However, the derived equations for determining the sample's μa and Γ require calibration of the setup using aqueous ink dilutions. Initial measurements are done with biological samples relevant to biomedical imaging such as human whole blood, joint and cyst fluids. Absorption of joint and cyst fluids is enhanced using a contrast agent like aqueous indocyanine green dye solution. For blood sample, measured values of μa = 0.580 +/- 0.016 mm-1 and Γ = 0.166 +/- 0.006 are within the range of values reported in literature. Measurements with the absorbing joint and cyst fluid samples give Γ values close to 0.12, which is similar to that of water and plasma.

  10. A frameshift mutation in the cubilin gene (CUBN) in Beagles with Imerslund-Gräsbeck syndrome (selective cobalamin malabsorption).

    PubMed

    Drögemüller, Michaela; Jagannathan, Vidhya; Howard, Judith; Bruggmann, Rémy; Drögemüller, Cord; Ruetten, Maja; Leeb, Tosso; Kook, Peter H

    2014-02-01

    Mammals are unable to synthesize cobalamin or vitamin B12 and rely on the uptake of dietary cobalamin. The cubam receptor expressed on the intestinal endothelium is required for the uptake of cobalamin from the gut. Cubam is composed of two protein subunits, amnionless and cubilin, which are encoded by the AMN and CUBN genes respectively. Loss-of-function mutations in either the AMN or the CUBN gene lead to hereditary selective cobalamin malabsorption or Imerslund-Gräsbeck syndrome (IGS). We investigated Beagles with IGS and resequenced the whole genome of one affected Beagle at 15× coverage. The analysis of the AMN and CUBN candidate genes revealed a homozygous deletion of a single cytosine in exon 8 of the CUBN gene (c.786delC). This deletion leads to a frameshift and early premature stop codon (p.Asp262Glufs*47) and is, thus, predicted to represent a complete loss-of-function allele. We tested three IGS-affected and 89 control Beagles and found perfect association between the IGS phenotype and the CUBN:c.786delC variant. Given the known role of cubilin in cobalamin transport, which has been firmly established in humans and dogs, our data strongly suggest that the CUBN:c.786delC variant is causing IGS in the investigated Beagles.

  11. Kinetic and thermodynamic characterization of a halotolerant β-galactosidase produced by halotolerant Aspergillus tubingensis GR1.

    PubMed

    Raol, Gopalkumar G; Raol, B V; Prajapati, Vimal S; Patel, Kamlesh C

    2015-07-01

    β-Galactosidase from halotolerant Aspergillus tubingensis GR1 was purified by two-step purification process comprising ammonium sulfate precipitation followed by size exclusion chromatography (SEC). The recovery of β-galactosidase after SEC was found to be 1.40% with 58.55-fold increase in specific activity. The molecular weight of β-galactosidase protein was found to be 93 kDa by SDS-PAGE. Activation energy for O-nitrophenol β-D-galactopyranoside (ONPG) hydrolysis was 32.88 kJ mol(-1), while temperature quotient (Q(10)) was found to be 1.375. The enzyme was found to be stable over wide pH range and thermally stable at 60-65°C up to 60 min of incubation while exhibited maximum activity at 65°C with pH 3.0. V(max), K(m), and K(cat) for ONPG were found to be 2000 U ml(-1), 8.33 mM (ONPG), and 101454 s(-1), respectively. Activation energy for irreversible inactivation Ea(d) of β-galactosidase was 100.017 kJ mol(-1). Thermodynamic parameters of irreversible inactivation of β-galactosidase and ONPG hydrolysis were also determined. However, β-galactosidase enzyme activity was activated significantly in the presence of 15% NaCl and hence shows activity up to 30% NaCl concentration.

  12. Simulating atmospheric transport of the 2011 Grímsvötn ash cloud using a data insertion update scheme

    NASA Astrophysics Data System (ADS)

    Wilkins, K. L.; Western, L. M.; Watson, I. M.

    2016-09-01

    Effective modelling of atmospheric volcanic ash dispersion is important to ensure aircraft safety, and has been the subject of much study since the Eyjafjallajökull ash crisis in Europe in 2010. In this paper, a novel modelling method is presented, where the atmospheric transport of the 2011 Grímsvötn ash cloud is simulated using a data insertion update scheme. Output from the volcanic ash transport and dispersion model, NAME, is updated using satellite retrievals and the results of a probabilistic ash, cloud and clear sky classification algorithm. A range of configurations of the scheme are compared with each other, in addition to a simple data insertion method presented in a previous study. Results show that simulations in which ash layer heights and depths are updated using the model output generally perform worse in relation to satellite derived ash coverage and ash column loading than simulations that use satellite-retrieved heights and an assumed layer depth of 1.0 km. Simulated ash column loading and concentration tends to be under-predicted using this update scheme, but the timing of the arrival of the ash cloud at Stockholm is well captured, as shown by comparison with lidar-derived mass concentration profiles. Most of the updated simulations in this comparison make small gains in skill on the simple data insertion scheme.

  13. GR SUMOylation and formation of an SUMO-SMRT/NCoR1-HDAC3 repressing complex is mandatory for GC-induced IR nGRE-mediated transrepression

    PubMed Central

    Hua, Guoqiang; Paulen, Laetitia; Chambon, Pierre

    2016-01-01

    Unique among the nuclear receptor superfamily, the glucocorticoid (GC) receptor (GR) can exert three distinct transcriptional regulatory functions on binding of a single natural (cortisol in human and corticosterone in mice) and synthetic [e.g., dexamethasone (Dex)] hormone. The molecular mechanisms underlying GC-induced positive GC response element [(+)GRE]-mediated activation of transcription are partially understood. In contrast, these mechanisms remain elusive for GC-induced evolutionary conserved inverted repeated negative GC response element (IR nGRE)-mediated direct transrepression and for tethered indirect transrepression that is mediated by DNA-bound NF-κB/activator protein 1 (AP1)/STAT3 activators and instrumental in GC-induced anti-inflammatory activity. We demonstrate here that SUMOylation of lysine K293 (mouse K310) located within an evolutionary conserved sequence in the human GR N-terminal domain allows the formation of a GR-small ubiquitin-related modifiers (SUMOs)-NCoR1/SMRT-HDAC3 repressing complex mandatory for GC-induced IR nGRE-mediated direct repression in vitro, but does not affect transactivation. Importantly, these results were validated in vivo: in K310R mutant mice and in mice ablated selectively for nuclear receptor corepressor 1 (NCoR1)/silencing mediator for retinoid or thyroid-hormone receptors (SMRT) corepressors in skin keratinocytes, Dex-induced direct repression and the formation of repressing complexes on IR nGREs were impaired, whereas transactivation was unaffected. In mice selectively ablated for histone deacetylase 3 (HDAC3) in skin keratinocytes, GC-induced direct repression, but not bindings of GR and of corepressors NCoR1/SMRT, was abolished, indicating that HDAC3 is instrumental in IR nGRE-mediated repression. Moreover, we demonstrate that the binding of HDAC3 to IR nGREs in vivo is mediated through interaction with SMRT/NCoR1. We also show that the GR ligand binding domain (LBD) is not required for SMRT

  14. PrCYP707A1, an ABA catabolic gene, is a key component of Phelipanche ramosa seed germination in response to the strigolactone analogue GR24

    PubMed Central

    Delavault, Philippe

    2012-01-01

    After a conditioning period, seed dormancy in obligate root parasitic plants is released by a chemical stimulus secreted by the roots of host plants. Using Phelipanche ramosa as the model, experiments conducted in this study showed that seeds require a conditioning period of at least 4 d to be receptive to the synthetic germination stimulant GR24. A cDNA-AFLP procedure on seeds revealed 58 transcript-derived fragments (TDFs) whose expression pattern changed upon GR24 treatment. Among the isolated TDFs, two up-regulated sequences corresponded to an abscisic acid (ABA) catabolic gene, PrCYP707A1, encoding an ABA 8'-hydroxylase. Using the rapid amplification of cDNA ends method, two full-length cDNAs, PrCYP707A1 and PrCYP707A2, were isolated from seeds. Both genes were always expressed at low levels during conditioning during which an initial decline in ABA levels was recorded. GR24 application after conditioning triggered a strong up-regulation of PrCYP707A1 during the first 18h, followed by an 8-fold decrease in ABA levels detectable 3 d after treatment. In situ hybridization experiments on GR24-treated seeds revealed a specific PrCYP707A1 mRNA accumulation in the cells located between the embryo and the micropyle. Abz-E2B, a specific inhibitor of CYP707A enzymes, significantly impeded seed germination, proving to be a non-competitive antagonist of GR24 with reversible inhibitory activity. These results demonstrate that P. ramosa seed dormancy release relies on ABA catabolism mediated by the GR24-dependent activation of PrCYP707A1. In addition, in situ hybridization corroborates the putative location of cells receptive to the germination stimulants in seeds. Abbreviations:ABAabscisic acidAbzabscinazoleAECadenylate energy chargeAFLPamplified fragment length polymorphismRACErapid amplification of cDNA endsSLstrigolactoneTDFtranscript-derived fragment PMID:22859674

  15. The Grapevine Root-Specific Aquaporin VvPIP2;4N Controls Root Hydraulic Conductance and Leaf Gas Exchange under Well-Watered Conditions But Not under Water Stress1[W

    PubMed Central

    Perrone, Irene; Gambino, Giorgio; Chitarra, Walter; Vitali, Marco; Pagliarani, Chiara; Riccomagno, Nadia; Balestrini, Raffaella; Kaldenhoff, Ralf; Uehlein, Norbert; Gribaudo, Ivana; Schubert, Andrea; Lovisolo, Claudio

    2012-01-01

    We functionally characterized the grape (Vitis vinifera) VvPIP2;4N (for Plasma membrane Intrinsic Protein) aquaporin gene. Expression of VvPIP2;4N in Xenopus laevis oocytes increased their swelling rate 54-fold. Northern blot and quantitative reverse transcription-polymerase chain reaction analyses showed that VvPIP2;4N is the most expressed PIP2 gene in root. In situ hybridization confirmed root localization in the cortical parenchyma and close to the endodermis. We then constitutively overexpressed VvPIP2;4N in grape ‘Brachetto’, and in the resulting transgenic plants we analyzed (1) the expression of endogenous and transgenic VvPIP2;4N and of four other aquaporins, (2) whole-plant, root, and leaf ecophysiological parameters, and (3) leaf abscisic acid content. Expression of transgenic VvPIP2;4N inhibited neither the expression of the endogenous gene nor that of other PIP aquaporins in both root and leaf. Under well-watered conditions, transgenic plants showed higher stomatal conductance, gas exchange, and shoot growth. The expression level of VvPIP2;4N (endogenous + transgene) was inversely correlated to root hydraulic resistance. The leaf component of total plant hydraulic resistance was low and unaffected by overexpression of VvPIP2;4N. Upon water stress, the overexpression of VvPIP2;4N induced a surge in leaf abscisic acid content and a decrease in stomatal conductance and leaf gas exchange. Our results show that aquaporin-mediated modifications of root hydraulics play a substantial role in the regulation of water flow in well-watered grapevine plants, while they have a minor role upon drought, probably because other signals, such as abscisic acid, take over the control of water flow. PMID:22923680

  16. Synthesis and structure of the extended phosphazane ligand [(1,4-C6H4){N(μ-PN(t)Bu)2N(t)Bu}2](4).

    PubMed

    Sevilla, Raquel; Less, Robert J; García-Rodríguez, Raúl; Bond, Andrew D; Wright, Dominic S

    2016-02-01

    The reaction of the phenylene-bridged precursor (1,4-C6H4)[N(PCl2)2]2 with (t)BuNH2 in the presence of Et3N gives the new ligand precursor (1,4-C6H4)[N(μ-N(t)Bu)2(PNH(t)Bu)2]2, deprotonation of which with Bu2Mg gives the novel tetraanion [(1,4-C6H4){N(μ-N(t)Bu)2(PN(t)Bu)2}2](4-).

  17. Trapping of Li(+) Ions by [ThFn](4-n) Clusters Leading to Oscillating Maxwell-Stefan Diffusivity in the Molten Salt LiF-ThF4.

    PubMed

    Chakraborty, Brahmananda; Kidwai, Sharif; Ramaniah, Lavanya M

    2016-08-18

    A molten salt mixture of lithium fluoride and thorium fluoride (LiF-ThF4) serves as a fuel as well as a coolant in the most sophisticated molten salt reactor (MSR). Here, we report for the first time dynamic correlations, Onsager coefficients, Maxwell-Stefan (MS) diffusivities, and the concentration dependence of density and enthalpy of the molten salt mixture LiF-ThF4 at 1200 K in the composition range of 2-45% ThF4 and also at eutectic composition in the temperature range of 1123-1600 K using Green-Kubo formalism and equilibrium molecular dynamics simulations. We have observed an interesting oscillating pattern for the MS diffusivity for the cation-cation pair, in which ĐLi-Th oscillates between positive and negative values with the amplitude of the oscillation reducing as the system becomes rich in ThF4. Through the velocity autocorrelation function, vibrational density of states, radial distribution function analysis, and structural snapshots, we establish an interplay between the local structure and multicomponent dynamics and predict that formation of negatively charged [ThFn](4-n) clusters at a higher ThF4 mole % makes positively charged Li(+) ions oscillate between different clusters, with their range of motion reducing as the number of [ThFn](4-n) clusters increases, and finally Li(+) ions almost get trapped at a higher ThF4% when the electrostatic force on Li(+) exerted by various surrounding clusters gets balanced. Although reports on variations of density and enthalpy with temperature exist in the literature, for the first time we report variations of the density and enthalpy of LiF-ThF4 with the concentration of ThF4 (mole %) and fit them with the square root function of ThF4 concentration, which will be very useful for experimentalists to obtain data over a range of concentrations from fitting the formula for design purposes. The formation of [ThFn](4-n) clusters and the reduction in the diffusivity of the ions at a higher ThF4% may limit the

  18. Trapping of Li(+) Ions by [ThFn](4-n) Clusters Leading to Oscillating Maxwell-Stefan Diffusivity in the Molten Salt LiF-ThF4.

    PubMed

    Chakraborty, Brahmananda; Kidwai, Sharif; Ramaniah, Lavanya M

    2016-08-18

    A molten salt mixture of lithium fluoride and thorium fluoride (LiF-ThF4) serves as a fuel as well as a coolant in the most sophisticated molten salt reactor (MSR). Here, we report for the first time dynamic correlations, Onsager coefficients, Maxwell-Stefan (MS) diffusivities, and the concentration dependence of density and enthalpy of the molten salt mixture LiF-ThF4 at 1200 K in the composition range of 2-45% ThF4 and also at eutectic composition in the temperature range of 1123-1600 K using Green-Kubo formalism and equilibrium molecular dynamics simulations. We have observed an interesting oscillating pattern for the MS diffusivity for the cation-cation pair, in which ĐLi-Th oscillates between positive and negative values with the amplitude of the oscillation reducing as the system becomes rich in ThF4. Through the velocity autocorrelation function, vibrational density of states, radial distribution function analysis, and structural snapshots, we establish an interplay between the local structure and multicomponent dynamics and predict that formation of negatively charged [ThFn](4-n) clusters at a higher ThF4 mole % makes positively charged Li(+) ions oscillate between different clusters, with their range of motion reducing as the number of [ThFn](4-n) clusters increases, and finally Li(+) ions almost get trapped at a higher ThF4% when the electrostatic force on Li(+) exerted by various surrounding clusters gets balanced. Although reports on variations of density and enthalpy with temperature exist in the literature, for the first time we report variations of the density and enthalpy of LiF-ThF4 with the concentration of ThF4 (mole %) and fit them with the square root function of ThF4 concentration, which will be very useful for experimentalists to obtain data over a range of concentrations from fitting the formula for design purposes. The formation of [ThFn](4-n) clusters and the reduction in the diffusivity of the ions at a higher ThF4% may limit the

  19. Theoretical study for the excited states of MoO4 - nS2 - n (n=0 ~ 4) and MoSe2 - 4

    NASA Astrophysics Data System (ADS)

    Nakatsuji, Hiroshi; Saito, Shinji

    1990-08-01

    Ground and excited states of six molybdenum complexes, MoO4-nS2-n (n=0˜4) and MoSe2-4, are systematically studied by symmetry adapted cluster (SAC) and SAC-CI theories. In the ground states, the ionicity of MoO2-4 is much larger than those of MoS2-4 and MoSe2-4. The calculated electronic spectra compare well with the observed spectra. New systematic assignments of the spectra are given. Most of the peaks are assigned to the electron-transfer type transitions from ligands to the metal. Many assignments are different from the previous ones. The observed relationships in the electronic spectra of these complexes are examined and corrected. The solvation effect is argued briefly.

  20. Endo-N-acetyl-beta-D-glucosaminidase and peptide-N4-(N-acetyl-glucosaminyl) asparagine amidase activities during germination of Raphanus sativus.

    PubMed

    Berger, S; Menudier, A; Julien, R; Karamanos, Y

    1995-06-01

    Endo-N-acetyl-beta-D-glucosaminidase (ENGase, EC 3.2.1.96) and peptide-N4-(N-acetyl-beta-D-glucosaminyl) asparagine amidase (PNGase, EC 3.5.1.52) activities were monitored during germination and postgerminative development in Raphanus sativus. The PNGase activity was found in dry seeds and its level was constant during germination and postgermination. The ENGase activity was first detected about 18 hr after the start of imbibition (HAI) and displayed a maximum level at 36 HAI. After 36 HAI the production of both enzymes was constant until days 4-5. Both enzymes displayed substrate specificities corresponding to the potential glycoprotein substrates found in plants. They are in agreement (i) with the hypothesis that ENGase and PNGase are at the origin of the production of 'unconjugated N-glycans' and (ii) with the possibility that protein activity could be regulated by the removal of N-glycans.

  1. Dependency of temperature on polarization in CH{sub 4}/N{sub 2} dielectric barrier discharge plasma: A crude assumption

    SciTech Connect

    Majumdar, Abhijit; Hippler, Rainer; Ghosh, Basudev

    2010-11-15

    We have investigated the variations of polarization (P) and the temperature ({Delta}T) at the electrode surfaces during the deposition of C-N layer in CH{sub 4}/N{sub 2} (1:2) dielectric barrier discharge plasma. The reactive deposition process influences the surface temperature, polarization, and the value of the in situ dielectric constant. We have developed a crude model that correlates the surface temperature and surface polarization with thin film properties. We assume that during the thin film deposition process, the atomic mean kinetic energy is equal to the electrostatic energy stored in the electrode surface area. Theoretically estimated temperature is found to agree well with the experimental results. However, the linear model thus developed cannot be used to explain the phenomena in the interfacial polarization stage that requires a nonlinear theory.

  2. Using Raman spectroscopy to understand the origin of the phase transitions observed in [(C3H7)4N]2Zn2Cl6 compound

    NASA Astrophysics Data System (ADS)

    Ben Gzaiel, M.; Oueslati, A.; Chaabane, I.; Bulou, A.; Hlel, F.; Gargouri, M.

    2015-06-01

    Phase transitions of the centrosymmetric compound, [(C3H7)4N]2Zn2Cl6, were studied by differential scanning calorimetry (DSC), X-ray diffraction, Raman spectroscopy and dielectric measurements. Two reversible order-disorder and displacive phase transitions are observed at T1 = 327 K and T2 = 347 K with 3 K and 4 K hysteresis respectively, indicating a first order character. The evolution of Raman line shifts, "ν", and the half-width, "Δν", versus temperature show some singularities associated with the transitions, suggesting that they are governed by the reorientational and the displacement of the organic part. Besides the results of the dielectric permittivity study confirms the conclusion drawn from the calorimetric and Raman measurements that the phase transition located in the vicinity of the temperature of the dielectric proprieties is characterized by change of dynamical state of cation.

  3. EFFICIENT CONTROL OVER THE PORE STRUCTURE OF Fe3O4-nSiO2-mSiO2 CORE-SHELL NANOPARTICLES

    NASA Astrophysics Data System (ADS)

    Liu, Feng; Tian, Hua; He, Junhui; Liu, Hongying

    2012-01-01

    In this paper, magnetic mesoporous silica nanoparticles (Fe3O4-nSiO2-mSiO2) were synthesized using trimethylbenzene (TMB) as a swelling agent. These composite nanoparticles have a typical sandwich structure with a magnetic core, a nonporous silica middle layer and an ordered mesoporous silica outer shell. The experimental results indicate that the magnetic mesoporous silica nanoparticles have high specific surface area (510 m2/g), large pore size (3.8 nm) and pore volume (1.04 cm3/g). The thickness and pore structure of the out shell can also be easily tailored by adjusting the reaction conditions. The obtained nanomaterials were characterized by X-ray diffraction, transmission electron microscopy and nitrogen adsorption-desorption measurements.

  4. New yellow-emitting nitride phosphor SrAlSi4N7:Ce3+ and important role of excessive AlN in material synthesis.

    PubMed

    Zhang, Liangliang; Zhang, Jiahua; Zhang, Xia; Hao, Zhendong; Zhao, Haifeng; Luo, Yongshi

    2013-12-26

    Synthesis and luminescent properties of Ce(3+)-doped SrAlSi4N7 yellow-emitting phosphor are reported. In comparison with YAG: Ce(3+), the phosphor exhibits smaller thermal quenching and a broader emission band centering at 555 nm with a bandwidth as large as 115 nm, being suitable for fabricating high color rendering white LED. It is observed in material synthesis that intense luminescence can be achieved only in case of excessive AlN in the raw materials. The role of the excessive AlN is studied. The mechanism for existence of edge-sharing [AlN4] tetrahedral, which is unreasonable according to the aluminum avoidance principle, is discussed in detail.

  5. Quasi-one-dimensional quantum spin liquid in the Cu(C4H4N2)(NO3)2 insulator

    NASA Astrophysics Data System (ADS)

    Shaginyan, V. R.; Stephanovich, V. A.; Popov, K. G.; Kirichenko, E. V.

    2016-01-01

    We analyze measurements of the magnetization, differential susceptibility and specific heat of quasi-onedimensional insulator Cu(C4H4N2)(NO3)2 (CuPzN) subjected to magnetic fields. We show that the thermodynamic properties are defined by quantum spin liquid formed with spinons, with the magnetic field tuning the insulator CuPzN towards quantum critical point related to fermion condensation quantum phase transition (FCQPT) at which the spinon effective mass diverges kinematically. We show that the FCQPT concept permits to reveal and explain the scaling behavior of thermodynamic characteristics. For the first time, we construct the schematic T-H (temperature-magnetic field) phase diagram of CuPzN that contains Landau-Fermi-liquid, crossover and non-Fermi liquid parts, thus resembling that of heavy-fermion compounds.

  6. Sectoral CO 2, CH 4, N 2O and SO 2 emissions from fossil fuel consumption in Nagpur City of Central India

    NASA Astrophysics Data System (ADS)

    Majumdar, Deepanjan; Gajghate, D. G.

    2011-08-01

    Emission inventory of CO 2, CH 4, N 2O and SO 2 has been prepared for Nagpur city in Central India for the year 2004. Data on fossil fuel (coal, light diesel oil, high speed diesel, petrol/gasoline, low sulphur heavy stock, furnace oil and kerosene) consumption in thermal power, industrial, transport and domestic sectors were collected. Thermal power sector had the maximum coal consumption followed by the industrial and domestic sectors, whereas kerosene, liquefied petroleum gas (LPG), diesel and gasoline were used only in any single sector. Total annual CO 2, CH 4, N 2O and SO 2 emissions from these fuels in Nagpur city for the year 2004 was found to be 14792418 MT (14.8 Tg), 4649 (4.6 Tg), 1529 (1.5 Tg) and 69093 (6.9 Tg), respectively, in which thermal power and domestic sector had the maximum share. Coal was found to be the major contributor to Green House Gas (GHG) and SO 2 emissions in all the sectors barring transport and domestic sectors. Carbon dioxide was the predominant GHG emitted by the selected sectors in terms of absolute emissions and also global warming contribution (GWC), though the share in the latter was lesser in magnitude due to higher global warming potential (GWP) of CH 4 and N 2O than CO 2. Thermal power sector had a share of 51% in total CO 2 emissions from all the sectors, followed by domestic, industrial and transport sectors having 27, 12 and 10% contributions, respectively. Share of thermal power sector in total SO 2 emissions was 61%, followed by 24% from industrial, 10% from domestic and 5% from transport sector.

  7. Analysis of the Vibrational Spectra of P_3N_3(OCH_2CF_3)_6 and P_4N_4(OCH_2CF_3)_8

    NASA Astrophysics Data System (ADS)

    King, Adrian K.; Plant, David F.; Golding, Peter; Lawson, Michael A.; Davies, Paul B.

    2011-06-01

    The cyclic phosphazene trimer P_3N_3(OCH_2CF_3)_6 and the related cyclic tetramer P_4N_4(OCH_2CF_3)_8 have been proposed as the major low-to-medium temperature pyrolysis products of the parent polyphosphazene (PN(OCH_2CF_3)_2)_n. Recently, both molecules have been synthesized, isolated and their vapour-phase vibrational spectra recorded using a high-resolution FTIR instrument. The interpretation of these spectra is achieved primarily by comparison with the results of high-quality density functional calculations, which enable the principal absorption features to be assigned and conclusions to be drawn regarding the geometries and conformations adopted by both molecules. These in turn allow interesting comparisons to be made with analogous cyclic halo-phosphazenes such as P_3N_3Cl_6 and P_4N_4Cl_8. Work to record in situ the spectra of the vapour-phase pyrolysis products of (PN(OCH_2CF_3)_2)_n and to analyse these results in terms of the tetramer and trimer spectra will also be presented. S. V. Peddada and J. H. Magill Macromolecules 16 (1983) 1258-1264. H. R. Allcock, G. S. McDonnell, G. H. Riding, and I. Manners Chem. Mater. 2 (1990) 425-432. T. R. Manley and D. A. Williams Spectrochimica Acta 23A (1966) 149-165. V. Varma, J. R. Fernandez and C. N. R. Rao J. Mol. Struct. 198 (1989) 403-412.

  8. Structural, spectral, electrochemistry, thermal properties and theoretical studies on 4-[N, N-di(4-tolyl)amino] benzaldehyde-2-chloro benzoylhydrazone

    NASA Astrophysics Data System (ADS)

    Lizeng, Liu; Wei, Li; Xianfang, Meng; Dongzhi, Liu; Gongfeng, Xu; Zhengchen, Bai

    2014-11-01

    The title compound 4-[N, N-di(4-tolyl)amino] benzaldehyde-2-chloro benzoylhydrazone (C28H24ClN3O, Mr = 453.96) was synthesized by the reaction of 4-[N, N-di(4-tolyl)amino] benzaldehyde with 2-chlorobenzohydrazide, and its structure was characterized by IR, 1H NMR, 13H NMR, high-resolution mass spectrometry and single-crystal X-ray diffraction. The crystal belongs to Monoclinic, space group P2(1)/n with a = 12.626(3), b = 12.609(3), c = 15.837(3) Å, β = 90.00(3)°, Z = 5, V = 2512.5(9) Å3, Mr = 453.95, Dc = 1.280 g/cm3, μ = 0.183 mm-1, F(0 0 0) = 1024, R = 0.0432 and wR = 0.1087. X-ray analysis revealed that one of the benzene ring and acylhydrazone were essentially planar, the 2-chloro benzene ring and amide were non-planar, the torsion angles C(1)sbnd C(6)sbnd C(7)sbnd O(1) and C(5)sbnd C(6)sbnd C(7)sbnd O(1) are 61.4(5)° and -114.4(4)°. The thermal stability studies indicate that the title compound is stable up to 341.1 °C. The spectral, electrochemistry properties and theoretical studies show that the title compound is a good candidate for the charge-transporting materials.

  9. Influence of terminal substitution on structural, DNA, protein binding, anticancer and antibacterial activities of palladium(II) complexes containing 3-methoxy salicylaldehyde-4(N) substituted thiosemicarbazones.

    PubMed

    Kalaivani, P; Prabhakaran, R; Ramachandran, E; Dallemer, F; Paramaguru, G; Renganathan, R; Poornima, P; Vijaya Padma, V; Natarajan, K

    2012-02-28

    The variable chelating behavior of 3-methoxysalicylaldehyde-4(N)-substituted thiosemicarbazones was observed in equimolar reactions with [PdCl(2)(PPh(3))(2)]. The new complexes were characterized by various analytical, spectroscopic techniques (mass, (1)H-NMR, absorption, IR). All the new complexes were structurally characterized by single crystal X-ray diffraction. Crystallographic results showed that the ligands H(2)L(1) and H(2)L(4) are coordinated as binegative tridentate ONS donor ligands in the complexes 1 and 4 by forming six and five member rings. However, the ligands H(2)L(2) and H(2)L(3) bound to palladium in 2 and 3 as uninegative bidentate NS donors by forming a five member chelate ring. From this study, it was found that the substitution on terminal 4(N)-nitrogen may have an influence on the chelating ability of thiosemicarbazone. The presence of hydrogen bonding in 2 and 3 might be responsible for preventing the coordination of phenolic oxygen to the metal ion. The interaction of the complexes with calf-thymus DNA (CT-DNA) has been explored by absorption and emission titration methods. Based on the observations, an electrostatic binding mode of DNA has been proposed. The protein binding studies were monitored by quenching of tryptophan and tyrosine residues in the presence of complexes using Lysozyme as model protein. Antibacterial activity studies of the complexes have been screened against pathogenic bacteria such as Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa. MIC50 values of the complexes showed that they exhibited significant activity against the pathogens and among them, 3 exhibited higher activity. Further, anticancer activity of the complexes on the lung cancer cell line A549 has also been studied. PMID:22222360

  10. Intrathecal dihydroergotamine inhibits capsaicin-induced vasodilatation in the canine external carotid circulation via GR127935- and rauwolscine-sensitive receptors.

    PubMed

    Marichal-Cancino, Bruno A; González-Hernández, Abimael; Manrique-Maldonado, Guadalupe; Ruiz-Salinas, Inna I; Altamirano-Espinoza, Alain H; MaassenVanDenBrink, Antoinette; Villalón, Carlos M

    2012-10-01

    It has been suggested that during a migraine attack trigeminal nerves release calcitonin gene-related peptide (CGRP), producing central nociception and vasodilatation of cranial arteries, including the extracranial branches of the external carotid artery. Since trigeminal inhibition may prevent this vasodilatation, the present study has investigated the effects of intrathecal dihydroergotamine on the external carotid vasodilatation to capsaicin, α-CGRP and acetylcholine. Anaesthetized vagosympathectomized dogs were prepared to measure blood pressure, heart rate and external carotid conductance. A catheter was inserted into the right common carotid artery for the continuous infusion of phenylephrine (to restore the carotid vascular tone), whereas the corresponding thyroid artery was cannulated for one-min intracarotid infusions of capsaicin, α-CGRP and acetylcholine (which dose-dependently increased the external carotid conductance). Another cannula was inserted intrathecally (C(1)-C(3)) for the administration of dihydroergotamine, the α(2)-adrenoceptor antagonist rauwolscine or the serotonin 5-HT(1B/1D) receptor antagonist GR127935 (N-[4-methoxy-3-(4-methyl-1-piperazinyl) phenyl]-2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)[1,1-biphenyl]-4-carboxamide hydrochloride monohydrate). Intrathecal dihydroergotamine (10, 31 and 100μg) inhibited the vasodilatation to capsaicin, but not that to α-CGRP or acetylcholine. This inhibition was: (i) unaffected by 10μg GR127935 or 100μg rauwolscine, but abolished by 31μg GR127935 or 310μg rauwolscine at 10μg dihydroergotamine; and (ii) abolished by the combination 10μg GR127935+100μg rauwolscine at 100μg dihydroergotamine. Thus, intrathecal (C(1)-C(3)) dihydroergotamine seems to inhibit the external carotid vasodilatation to capsaicin by spinal activation of serotonin 5-HT(1B/1D) (probably 5-HT(1B)) receptors and α(2) (probably α(2A/2C))-adrenoceptors.

  11. Quantitative Rh typing of r-Gr-G with observations on the nature of G (Rh 12) and anti-G.

    PubMed

    Rosenfield, R E; Levine, P; Heller, C

    1975-01-01

    Quantitative blood typing data on Mr. R. B. (r-Gr-G), his wife (R1r), a daughter (R1r-G), and a niece (r-Gr) strongly suggest that these Rh phenotypes are directly indicative of actual Rh genotypes. If so, the antigenic products of r-G are weak Rh2(rh' or C), normal Rh5 (hr" or e), an expression of Rh12 (rh-G) equal to that produced by R-1,2,-3 (r' or dCe) and half of what is produced by R1 (R or D) genes in either homozygous or heterozygous expression, very weak expression of Rh19 (hr-S), absence of Rh31 (hr-B), and slightly weakened expression of Rh17 (Hr-o or 'not D'). The LW status of r-Gr-G cells was equivalent to that of other Rh:-1 erythrocytes. Thus r-G resembles mutant r' in which only Rh5 is expressed normally. The weak Rh2 produced by r-G reacted much better with one Rh2 antiserum than with another. Rh21 (C-G) had been used to denote such additional reactivity, but one reagent that acted as anti-Rh2 in manual tests behaved like anti-Rh21 in instrumented tests. Therefore, anti-Rh21 may only indicate a more efficiently agglutinating anti-Rh2. Mr. R. B. showed no evidence of congenital stomatocytic hemolytic anemia characteristic of Rh-null or Rh-mod. Finally, anti-Rh12 eluates, recovered either sequentially from r'r followed by R2r or singly from r-Gr-G, agglutinated chimpanzee red cells more efficiently than did either anti-Rh1 (D) or anti-Rh4 (c), a result consistent with expectation for serological crossreactivity between Rh1 and Rh21.

  12. Ghrelin accelerates wound healing through GHS-R1a-mediated MAPK-NF-κB/GR signaling pathways in combined radiation and burn injury in rats

    PubMed Central

    Liu, Cong; Huang, Jiawei; Li, Hong; Yang, Zhangyou; Zeng, Yiping; Liu, Jing; Hao, Yuhui; Li, Rong

    2016-01-01

    The therapeutic effect of ghrelin on wound healing was assessed using a rat model of combined radiation and burn injury (CRBI). Rat ghrelin, anti-rat tumor necrosis factor (TNF) α polyclonal antibody (PcAb), or selective antagonists of p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), and growth hormone secretagogue receptor (GHS-R) 1a (SB203580, SP600125, and [D-Lys3]-GHRP-6, respectively), were administered for seven consecutive days. Levels of various signaling molecules were assessed in isolated rat peritoneal macrophages. The results showed that serum ghrelin levels and levels of macrophage glucocorticoid receptor (GR) decreased, while phosphorylation of p38MAPK, JNK, and p65 nuclear factor (NF) κB increased. Ghrelin inhibited the serum induction of proinflammatory mediators, especially TNF-α, and promoted wound healing in a dose-dependent manner. Ghrelin treatment decreased phosphorylation of p38MAPK, JNK, and p65NF-κB, and increased GR levels in the presence of GHS-R1a. SB203580 or co-administration of SB203580 and SP600125 decreased TNF-α level, which may have contributed to the inactivation of p65NF-κB and increase in GR expression, as confirmed by western blotting. In conclusion, ghrelin enhances wound recovery in CRBI rats, possibly by decreasing the induction of TNF-α or other proinflammatory mediators that are involved in the regulation of GHS-R1a-mediated MAPK-NF-κB/GR signaling pathways. PMID:27271793

  13. Quantitative Rh typing of r-Gr-G with observations on the nature of G (Rh 12) and anti-G.

    PubMed

    Rosenfield, R E; Levine, P; Heller, C

    1975-01-01

    Quantitative blood typing data on Mr. R. B. (r-Gr-G), his wife (R1r), a daughter (R1r-G), and a niece (r-Gr) strongly suggest that these Rh phenotypes are directly indicative of actual Rh genotypes. If so, the antigenic products of r-G are weak Rh2(rh' or C), normal Rh5 (hr" or e), an expression of Rh12 (rh-G) equal to that produced by R-1,2,-3 (r' or dCe) and half of what is produced by R1 (R or D) genes in either homozygous or heterozygous expression, very weak expression of Rh19 (hr-S), absence of Rh31 (hr-B), and slightly weakened expression of Rh17 (Hr-o or 'not D'). The LW status of r-Gr-G cells was equivalent to that of other Rh:-1 erythrocytes. Thus r-G resembles mutant r' in which only Rh5 is expressed normally. The weak Rh2 produced by r-G reacted much better with one Rh2 antiserum than with another. Rh21 (C-G) had been used to denote such additional reactivity, but one reagent that acted as anti-Rh2 in manual tests behaved like anti-Rh21 in instrumented tests. Therefore, anti-Rh21 may only indicate a more efficiently agglutinating anti-Rh2. Mr. R. B. showed no evidence of congenital stomatocytic hemolytic anemia characteristic of Rh-null or Rh-mod. Finally, anti-Rh12 eluates, recovered either sequentially from r'r followed by R2r or singly from r-Gr-G, agglutinated chimpanzee red cells more efficiently than did either anti-Rh1 (D) or anti-Rh4 (c), a result consistent with expectation for serological crossreactivity between Rh1 and Rh21. PMID:804766

  14. Source parameters for the 2013-2015 earthquake sequence in Nógrád county, Hungary

    NASA Astrophysics Data System (ADS)

    Wéber, Zoltán

    2016-07-01

    Between 2013 June and 2015 January, 35 earthquakes with local magnitude M L ranging from 1.1 to 4.2 occurred in Nógrád county, Hungary. This earthquake sequence represents above average seismic activity in the region and is the first one that was recorded by a significant number of three-component digital seismographs in the county. Using a Bayesian multiple-event location algorithm, we have estimated the hypocenters of 30 earthquakes with M L ≥1.5. The events occurred in two small regions of a few squared kilometers: one to the east of Érsekvadkert and the other at Iliny. The uncertainty of the epicenters is about 1.5-1.7 km in the E-W direction and 1.8-2.1 km in the N-S direction at the 95 % confidence level. The estimated event depths are confined to the upper 3 km of the crust. We have successfully estimated the full moment tensors of 4 M w ≥3.6 earthquakes using a probabilistic waveform inversion procedure. The non-double-couple components of the retrieved moment tensor solutions are statistically insignificant. The negligible amount of the isotropic component implies the tectonic nature of the investigated events. All of the analyzed earthquakes have strike-slip mechanism with either right-lateral slip on an approximately N-S striking or left-lateral movement on a roughly E-W striking nodal plane. The orientations of the obtained focal mechanisms are in good agreement with the main stress pattern published for the epicentral region. Both the P and T principal axes are horizontal, and the P axis is oriented along a NE-SW direction.

  15. EPSAH, an exopolysaccharide from Aphanothece halophytica GR02, improves both cellular and humoral immunity as a novel polysaccharide adjuvant.

    PubMed

    Zhu, Lei; Zhang, Fan; Yang, Li-Jun; Ge, Yang; Wei, Qing-Fang; Ou, Yu

    2016-07-01

    EPSAH is an exopolysaccharide from Aphanothece halophytica GR02. The present study was designed to evaluate its toxicity and adjuvant potential in the specific cellular and humoral immune responses in ovalbumin (OVA) in mice. EPSAH did not cause any mortality and side effects when the mice were administered subcutaneously twice at the dose of 50 mg·kg(-1). Hemolytic activity in vitro indicated that EPSAH was non-hemolytic. Splenocyte proliferation in vitro was assayed with different concentrations of EPSAH. The mice were immunized subcutaneously with OVA 0.1 mg alone or with OVA 0.1 mg dissolved in saline containing Alum (0.2 mg) or EPSAH (0.2, 0.4, or 0.8 mg) on Day 1 and 15. Two weeks later, splenocyte proliferation, natural killer (NK) cell activity, production of cytokines IL-2 from splenocytes, and serum OVA-specific antibody titers were measured. Phagocytic activity, production of pro-inflammatory cytokines IL-1 and IL-12 in mice peritoneal macrophages were also determined. EPSAH showed a dose-dependent stimulating effect on mitogen-induced proliferation. The Con A-, LPS-, and OVA-induced splenocyte proliferation and the serum OVA-specific IgG, IgG1, and IgG2a antibody titers in the immunized mice were significantly enhanced. EPSAH also significantly promoted the production of Th1 cytokine IL-2. Besides, EPSAH remarkably increased the killing activities of NK cells from splenocytes in the immunized mice. In addition, EPSAH enhanced phagocytic activity and the generation of pro-inflammatory cytokines IL-1 and IL-12 in macrophages. These results indicated that EPSAH had a strong potential to increase both cellular and humoral immune responses, particularly promoting the development of Th1 polarization. PMID:27507205

  16. Source parameters for the 2013–2015 earthquake sequence in Nógrád county, Hungary

    NASA Astrophysics Data System (ADS)

    Wéber, Zoltán

    2016-07-01

    Between 2013 June and 2015 January, 35 earthquakes with local magnitude M L ranging from 1.1 to 4.2 occurred in Nógrád county, Hungary. This earthquake sequence represents above average seismic activity in the region and is the first one that was recorded by a significant number of three-component digital seismographs in the county. Using a Bayesian multiple-event location algorithm, we have estimated the hypocenters of 30 earthquakes with M L ≥1.5. The events occurred in two small regions of a few squared kilometers: one to the east of Érsekvadkert and the other at Iliny. The uncertainty of the epicenters is about 1.5-1.7 km in the E-W direction and 1.8-2.1 km in the N-S direction at the 95 % confidence level. The estimated event depths are confined to the upper 3 km of the crust. We have successfully estimated the full moment tensors of 4 M w ≥3.6 earthquakes using a probabilistic waveform inversion procedure. The non-double-couple components of the retrieved moment tensor solutions are statistically insignificant. The negligible amount of the isotropic component implies the tectonic nature of the investigated events. All of the analyzed earthquakes have strike-slip mechanism with either right-lateral slip on an approximately N-S striking or left-lateral movement on a roughly E-W striking nodal plane. The orientations of the obtained focal mechanisms are in good agreement with the main stress pattern published for the epicentral region. Both the P and T principal axes are horizontal, and the P axis is oriented along a NE-SW direction.

  17. Biomimetic Trehalose Biosensor Using Gustatory Receptor (Gr5a) Expressed in Drosophila Cells and Ion-Sensitive Field-Effect Transistor

    NASA Astrophysics Data System (ADS)

    Lau, Hui-Chong; Bae, Tae-Eon; Jang, Hyun-June; Kwon, Jae-Young; Cho, Won-Ju; Lim, Jeong-Ok

    2013-04-01

    The development of potential applications of biosensors using the sensory systems of vertebrates and invertebrates has progressed rapidly, especially in clinical diagnosis. The biosensor developed here involves the use of Drosophila cells expressing the gustatory receptor Gr5a and an ion-sensitive field-effect transistor (ISFET) sensor device. Gustatory receptor Gr5a is expressed abundantly in gustatory neurons and acts as a primary marker for tastants, especially sugar, in Drosophila. As a result, it could potentially serve as a good candidate for potential biomarkers of diseases in which the current knowledge of the cause and treatment is limited. The developed ISFET was based on the outstanding electrical characteristics of the metal-oxide-semiconductor field-effect transistor (MOSFET) with a subthreshold swing of 85 mV/dec, low leakage current of <10-12 and high on/off current ratio of 7.3×106. The SiO2 sensing membrane with a pH sensitivity of 34.9 mV/pH and drift rate 1.17 mV/h was sufficient for biosensing applications. In addition, the sensor device also showed significant compatibility with the Drosophila cells expressing Gr5a and their response to sugar, particularly trehalose. Moreover, the interactions between the transfected Drosophila cells and trehalose were consistent and reliable. This suggests that the developed ISFET sensor device could have potential use in the future as a screening device in diagnosis.

  18. Hydrogen Sulfide Attenuates the Recruitment of CD11b+Gr-1+ Myeloid Cells and Regulates Bax/Bcl-2 Signaling in Myocardial Ischemia Injury

    PubMed Central

    Zhang, Youen; Li, Hua; Zhao, Gang; Sun, Aijun; Zong, Nobel C.; Li, Zhaofeng; Zhu, Hongming; Zou, Yunzeng; Yang, Xiangdong; Ge, Junbo

    2014-01-01

    Hydrogen sulfide, an endogenous signaling molecule, plays an important role in the physiology and pathophysiology of the cardiovascular system. Using a mouse model of myocardial infarction, we investigated the anti-inflammatory and anti-apoptotic effects of the H2S donor sodium hydrosulfide (NaHS). The results demonstrated that the administration of NaHS improved survival, preserved left ventricular function, limited infarct size, and improved H2S levels in cardiac tissue to attenuate the recruitment of CD11b+Gr-1+ myeloid cells and to regulate the Bax/Bcl-2 pathway. Furthermore, the cardioprotective effects of NaHS were enhanced by inhibiting the migration of CD11b+Gr-1+ myeloid cells from the spleen into the blood and by attenuating post-infarction inflammation. These observations suggest that the novel mechanism underlying the cardioprotective function of H2S is secondary to a combination of attenuation the recruitment of CD11b+Gr-1+ myeloid cells and regulation of the Bax/Bcl-2 apoptotic signaling. PMID:24758901

  19. Newly recruited CD11b+, GR-1+, Ly6C(high) myeloid cells augment tumor-associated immunosuppression immediately following the therapeutic administration of oncolytic reovirus.

    PubMed

    Clements, Derek R; Sterea, Andra M; Kim, Youra; Helson, Erin; Dean, Cheryl A; Nunokawa, Anna; Coyle, Krysta Mila; Sharif, Tanveer; Marcato, Paola; Gujar, Shashi A; Lee, Patrick W K

    2015-05-01

    Tumor-associated immunosuppression aids cancer cells to escape immune-mediated attack and subsequent elimination. Recently, however, many oncolytic viruses, including reovirus, have been reported to overturn such immunosuppression and promote the development of a clinically desired antitumor immunity, which is known to promote favorable patient outcomes. Contrary to this existing paradigm, in this article we demonstrate that reovirus augments tumor-associated immunosuppression immediately following its therapeutic administration. Our data show that reovirus induces preferential differentiation of highly suppressive CD11b(+), Gr-1(+), Ly6C(high) myeloid cells from bone marrow hematopoietic progenitor cells. Furthermore, reovirus administration in tumor-bearing hosts drives time-dependent recruitment of CD11b(+), Gr-1(+), Ly6C(high) myeloid cells in the tumor milieu, which is further supported by virus-induced increased expression of numerous immune factors involved in myeloid-derived suppressor cell survival and trafficking. Most importantly, CD11b(+), Gr-1(+), Ly6C(high) myeloid cells specifically potentiate the suppression of T cell proliferation and are associated with the absence of IFN-γ response in the tumor microenvironment early during oncotherapy. Considering that the qualitative traits of a specific antitumor immunity are largely dictated by the immunological events that precede its development, our findings are of critical importance and must be considered while devising complementary interventions aimed at promoting the optimum efficacy of oncolytic virus-based anticancer immunotherapies. PMID:25825443

  20. Potential differentiation of tumor bearing mouse CD11b+Gr-1+ immature myeloid cells into both suppressor macrophages and immunostimulatory dendritic cells.

    PubMed

    Narita, Yoshinori; Wakita, Daiko; Ohkur, Takayuki; Chamoto, Kenji; Nishimura, Takashi

    2009-02-01

    Evaluation of immunosuppressive tumor-escape mechanisms in tumor-bearing hosts is of great importance for the development of an efficient tumor immunotherapy. We document here the functional characteristics of CD11b(+)Gr-1(+) immature myeloid cells (ImC), which increase abnormally in tumor-bearing mice. Although it has been reported that ImC exhibit a strong immunosuppressive activity against T cell responses, we demonstrate that ImC derived from tumor-bearing mouse spleens (TB-SPL) did not exhibit a strong inhibitory activity against CTL generation in MLR. However, ImC isolated from TB-SPL and induced to differentiate into CD11b(+)Gr-1(+)F4/80(+) suppressor macrophages (MPhi) under the influence of tumor-derived factors were immunosuppressive. Furthermore, we also demonstrate that ImC isolated from TB-SPL had a capability of differentiating into immunostimulatory dendritic cells (DC1) supportive of the generation of IFN-gamma producing CTL if the ImC were cultured with Th1 cytokines plus GM-CSF and IL-3. Thus, our findings indicate that tumor bearing mouse-derived CD11b(+)Gr-1(+) ImC are not committed to development into immunosuppressor cells but have dual differentiation ability into both immunosuppressive myeloid cells and immunostimulatory DC1.

  1. Determining the mass fraction of external water in the plume of the 2011 eruption of Grímsvötn, Iceland

    NASA Astrophysics Data System (ADS)

    Gudmundsson, Magnus T.; Pálsson, Finnur; Thordarson, Thor; Höskuldsson, Ármann; Larsen, Gudrún; Högnadóttir, Thórdís; Oddsson, Björn; Óladóttir, Bergrún; Gudnason, Jónas

    2013-04-01

    The VEI4 eruption of Grímsvötn in May 2011 produced an up to 20-km high eruption plume with on over 100 km wide umbrella cloud. The plume was sustained at or above 15 km height for the first 24 hours of this 7-day long eruption. It alternated between wet, phreatomagmatic phases and dry magmatic phases, with over half of the erupted material formed during dry conditions. The eruption fissure was about 1.5 km long, located in the southwest part Grímsvötn, outside the boundaries of the subglacial Grímsvötn lake but within the topographic boundaries of the Grímsvötn caldera. Before the eruption this locality was mostly covered by 50-150 m thick ice. During the eruption the ice was melted, and a 700 m wide and up to 150 m deep ice cauldron with meltwater was formed. This meltwater lake within the cauldron surrounded and saturated the craters during the later and less energetic part of the eruption. The melting of this ice did at first not affect the surrounding glacier and the water level in the cauldron near the end of and shortly after the eruption was lower than in the subglacial Grímsvötn lake, about 1 km further to the northeast in the central part of the caldera. Apparently, no hydrological connection existed between the main subglacial lake and the eruption site during the eruption and it seems that no meltwater from the eruption was lost subglacially from the eruption site to the subglacial lake. The ice cauldron was therefore a system with only one open pathway for loss of meltwater - as steam added to the volcanic plume. Thus, the mass of ice melted, heated and evaporated could be determined. The eruption therefore provided a unique opportunity to quantify the mass of external water added to a volcanic plume. The results indicate that external water was 5-10% of the total mass of tephra erupted. Of the order of one fifth of the total thermal energy was used to generate the steam. This large external mass of steam modified the behaviour of the plume

  2. Design of a highly sensitive ethanol sensor using a nano-coaxial p-Co3O4/n-TiO2 heterojunction synthesized at low temperature

    NASA Astrophysics Data System (ADS)

    Liang, Y. Q.; Cui, Z. D.; Zhu, S. L.; Li, Z. Y.; Yang, X. J.; Chen, Y. J.; Ma, J. M.

    2013-10-01

    In this paper, we describe the design, fabrication and gas-sensing tests of nano-coaxial p-Co3O4/n-TiO2 heterojunction. Specifically, uniform TiO2 nanotubular arrays have been assembled by anodization and used as templates for generation of the Co3O4 one-dimensional nanorods. The structure morphology and composition of as-prepared products have been characterized by SEM, XRD, TEM, and XPS. A possible growth mechanism governing the formation of such nano-coaxial heterojunctions is proposed. The TiO2 nanotube sensor shows a normal n-type response to reducing ethanol gas, whereas TiO2-Co3O4 exhibits p-type response with excellent sensing performances. This conversion of sensing behavior can be explained by the formation of p-n heterojunction structures. A possible sensing mechanism is also illustrated, which can provide theoretical guidance for the further development of advanced gas-sensitive materials with p-n heterojunction.In this paper, we describe the design, fabrication and gas-sensing tests of nano-coaxial p-Co3O4/n-TiO2 heterojunction. Specifically, uniform TiO2 nanotubular arrays have been assembled by anodization and used as templates for generation of the Co3O4 one-dimensional nanorods. The structure morphology and composition of as-prepared products have been characterized by SEM, XRD, TEM, and XPS. A possible growth mechanism governing the formation of such nano-coaxial heterojunctions is proposed. The TiO2 nanotube sensor shows a normal n-type response to reducing ethanol gas, whereas TiO2-Co3O4 exhibits p-type response with excellent sensing performances. This conversion of sensing behavior can be explained by the formation of p-n heterojunction structures. A possible sensing mechanism is also illustrated, which can provide theoretical guidance for the further development of advanced gas-sensitive materials with p-n heterojunction. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr03616b

  3. Equation of state and thermodynamic Grüneisen parameter of monoclinic 1,1-diamino-2,2-dinitroethylene

    NASA Astrophysics Data System (ADS)

    Zhang, Jianzhong; Velisavljevic, Nenad; Zhu, Jinlong; Wang, Liping

    2016-10-01

    In situ synchrotron x-ray diffraction experiments were conducted on 1,1-diamino-2,2-dinitroethylene (FOX-7) at pressures up to 6.8 GPa and temperatures up to 485 K. Within the resolution of the present diffraction data, our results do not reveal evidence for a pressure-induced structural phase transition near 2 GPa, previously observed in several vibrational spectroscopy experiments. Based on unit-cell volume measurements, the least-squares fit using the third-order Birch-Murnaghan equation of state (EOS) yields K 0  =  12.6  ±  1.4 GPa and K0\\prime   =  11.3  ±  2.1 for the α-phase of FOX-7, which are in good agreement with recently reported values for the deuterated sample, indicating that the effect of hydrogen-deuterium substitution on the compressibility of FOX-7 is negligibly small. A thermal EOS is also obtained for the α-phase of FOX-7, including pressure dependence of thermal expansivity, (∂α/∂P)T  =  -7.0  ±  2.0  ×  10-5 K-1 GPa-1, and temperature derivative of the bulk modulus, (∂K T/∂T)P  =  -1.1  ×  10-2 GPa K-1. From these EOS parameters, we calculate heat capacity at constant volume (C V) and thermodynamic Grüneisen parameter (γ TH) as a function of temperature. At ambient conditions, the calculated γ TH is 1.055, which is in good agreement with the value (1.09) previously obtained from density functional theory (DFT). The obtained C V, however, is 13% larger than that calculated from the first-principles calculations, indicating that the dispersion correction in the DFT calculations may need to be further improved for describing intermolecular interactions of molecular crystals.

  4. Equation of state and thermodynamic Grüneisen parameter of monoclinic 1,1-diamino-2,2-dinitroethylene.

    PubMed

    Zhang, Jianzhong; Velisavljevic, Nenad; Zhu, Jinlong; Wang, Liping

    2016-10-01

    In situ synchrotron x-ray diffraction experiments were conducted on 1,1-diamino-2,2-dinitroethylene (FOX-7) at pressures up to 6.8 GPa and temperatures up to 485 K. Within the resolution of the present diffraction data, our results do not reveal evidence for a pressure-induced structural phase transition near 2 GPa, previously observed in several vibrational spectroscopy experiments. Based on unit-cell volume measurements, the least-squares fit using the third-order Birch-Murnaghan equation of state (EOS) yields K 0  =  12.6  ±  1.4 GPa and [Formula: see text]  =  11.3  ±  2.1 for the α-phase of FOX-7, which are in good agreement with recently reported values for the deuterated sample, indicating that the effect of hydrogen-deuterium substitution on the compressibility of FOX-7 is negligibly small. A thermal EOS is also obtained for the α-phase of FOX-7, including pressure dependence of thermal expansivity, (∂α/∂P)T  =  -7.0  ±  2.0  ×  10(-5) K(-1) GPa(-1), and temperature derivative of the bulk modulus, (∂K T/∂T)P  =  -1.1  ×  10(-2) GPa K(-1). From these EOS parameters, we calculate heat capacity at constant volume (C V) and thermodynamic Grüneisen parameter (γ TH) as a function of temperature. At ambient conditions, the calculated γ TH is 1.055, which is in good agreement with the value (1.09) previously obtained from density functional theory (DFT). The obtained C V, however, is 13% larger than that calculated from the first-principles calculations, indicating that the dispersion correction in the DFT calculations may need to be further improved for describing intermolecular interactions of molecular crystals. PMID:27494384

  5. Structural and Biochemical Analysis of the Hordeum vulgare L. HvGR-RBP1 Protein, a Glycine-Rich RNA-Binding Protein Involved in the Regulation of Barley Plant Development and Stress Response

    PubMed Central

    2015-01-01

    The timing of whole-plant senescence influences important agricultural traits such as yield and grain protein content. Post-transcriptional regulation by plant RNA-binding proteins is essential for proper control of gene expression, development, and stress responses. Here, we report the three-dimensional solution NMR structure and nucleic acid-binding properties of the barley glycine-rich RNA-binding protein HvGR-RBP1, whose transcript has been identified as being >45-fold up-regulated in early—as compared to late—senescing near-isogenic barley germplasm. NMR analysis reveals that HvGR-RBP1 is a multidomain protein comprising a well-folded N-terminal RNA Recognition Motif (RRM) and a structurally disordered C-terminal glycine-rich domain. Chemical shift differences observed in 2D 1H–15N correlation (HSQC) NMR spectra of full-length HvGR-RBP1 and N-HvGR-RBP1 (RRM domain only) suggest that the two domains can interact both in-trans and intramolecularly, similar to what is observed in the tobacco NtGR-RBP1 protein. Further, we show that the RRM domain of HvGR-RBP1 binds single-stranded DNA nucleotide fragments containing the consensus nucleotide sequence 5′-TTCTGX-3′ with low micromolar affinity in vitro. We also demonstrate that the C-terminal glycine-rich (HvGR) domain of Hv-GR-RBP1 can interact nonspecifically with ssRNA in vitro. Structural similarities with other plant glycine-rich RNA-binding proteins suggest that HvGR-RBP1 may be multifunctional. Based on gene expression analysis following cold stress in barley and E. coli growth studies following cold shock treatment, we conclude that HvGR-RBP1 functions in a manner similar to cold-shock proteins and harbors RNA chaperone activity. HvGR-RBP1 is therefore not only involved in the regulation of barley development including senescence, but also functions in plant responses to environmental stress. PMID:25495582

  6. Structural and biochemical analysis of the Hordeum vulgare L. HvGR-RBP1 protein, a glycine-rich RNA-binding protein involved in the regulation of barley plant development and stress response.

    PubMed

    Tripet, Brian P; Mason, Katelyn E; Eilers, Brian J; Burns, Jennifer; Powell, Paul; Fischer, Andreas M; Copié, Valérie

    2014-12-23

    The timing of whole-plant senescence influences important agricultural traits such as yield and grain protein content. Post-transcriptional regulation by plant RNA-binding proteins is essential for proper control of gene expression, development, and stress responses. Here, we report the three-dimensional solution NMR structure and nucleic acid-binding properties of the barley glycine-rich RNA-binding protein HvGR-RBP1, whose transcript has been identified as being >45-fold up-regulated in early-as compared to late-senescing near-isogenic barley germplasm. NMR analysis reveals that HvGR-RBP1 is a multidomain protein comprising a well-folded N-terminal RNA Recognition Motif (RRM) and a structurally disordered C-terminal glycine-rich domain. Chemical shift differences observed in 2D (1)H-(15)N correlation (HSQC) NMR spectra of full-length HvGR-RBP1 and N-HvGR-RBP1 (RRM domain only) suggest that the two domains can interact both in-trans and intramolecularly, similar to what is observed in the tobacco NtGR-RBP1 protein. Further, we show that the RRM domain of HvGR-RBP1 binds single-stranded DNA nucleotide fragments containing the consensus nucleotide sequence 5'-TTCTGX-3' with low micromolar affinity in vitro. We also demonstrate that the C-terminal glycine-rich (HvGR) domain of Hv-GR-RBP1 can interact nonspecifically with ssRNA in vitro. Structural similarities with other plant glycine-rich RNA-binding proteins suggest that HvGR-RBP1 may be multifunctional. Based on gene expression analysis following cold stress in barley and E. coli growth studies following cold shock treatment, we conclude that HvGR-RBP1 functions in a manner similar to cold-shock proteins and harbors RNA chaperone activity. HvGR-RBP1 is therefore not only involved in the regulation of barley development including senescence, but also functions in plant responses to environmental stress.

  7. DC-8-based observations of aircraft CO, CH4, N2O, and H2O(g) emission indices during SUCCESS

    NASA Astrophysics Data System (ADS)

    Vay, S. A.; Anderson, B. E.; Sachse, G. W.; Collins, J. E., Jr.; Podolske, J. R.; Twohy, C. H.; Gandrud, B.; Chan, K. R.; Baughcum, S. L.; Wallio, H. A.

    We report the first measurements of CO, CH4, N2O, CO2, and H2O(g) in the exhaust trails of T-39, B-757, and DC-8 aircraft at cruise conditions. Emission indices (EI) derived from these in-situ measurements are presented. Results are in agreement with ground-based tests indicating aircraft act as a net sink for CH4 and recent airborne in-situ measurements that N2O is not an important exhaust constituent. Condensation of H2O(g) on exhaust particles resulted in EI(H2O(g)) values less than those expected from the combustion of fuel alone. Observed apparent negative EI(H2O(g)) values suggest that aircraft aerosol emissions, under unique atmospheric conditions, seed cloud formation and lead to dehydration of the exhaust-influenced air parcel. Such conditions may induce the formation of cirrus clouds from persistent contrails. Comparisons with the Boeing EMIT Code show measurement-derived CO emission index values consistent with model evaluations.

  8. Electrical properties and conduction mechanism of [N(C2H5)4][N(CH3)4]CuCl4 compound

    NASA Astrophysics Data System (ADS)

    Drissi, N.; Karoui, K.; Jomni, F.; Rhaiem, A. Ben

    2016-09-01

    The [N(CH3)4][N(C2H5)4]CuCl4 single crystal has been synthetized in order to determinate the temperatures transition and to study the electrical properties and the conduction mechanism. At room temperature, this compound crystallizes in the tetragonal system with P-421m space group. The calorimetric study shows three anomalies at 248, 284 and 326 K. Electrical conduction and dielectrical relaxation mechanisms at various frequencies and temperatures were analyzed by impedance spectroscopy and the equivalent circuit based on the Z-View-software was proposed. The variation of fp relaxation determinate by the modulus study and σdc specific to the AC conductivity as a function of temperature and confirm the all transitions for our sample. The values of the activation energy are determined and compared by those, which are found in the similar compound. Frequencies dependence of alternative current (AC) conductivity is interpreted in terms of Jonscher's law and the conduction mechanisms for each phase are determined with the Elliot's theory.

  9. Multisite constrained model of trans-4-(N,N-dimethylamino)-4'-nitrostilbene for structural elucidation of radiative and nonradiative excited states.

    PubMed

    Lin, Cheng-Kai; Wang, Yu-Fu; Cheng, Yuan-Chung; Yang, Jye-Shane

    2013-04-18

    A constrained model compound of trans-4-(N,N-dimethylamino)-4'-nitrostilbene (DNS), namely, compound DNS-B3 that is limited to torsions about the phenyl-nitro C-N bond and the central C═C bond, was prepared to investigate the structural nature of the radiative and nonradiative states of electronically excited DNS. The great similarities in solvent-dependent electronic spectra, fluorescence decay times, and quantum yields for fluorescence (Φf) and trans → cis photoisomerization (Φtc) between DNS and DNS-B3 indicate that the fluorescence is from a planar charge-transfer state and torsion of the nitro group is sufficient to account for the nonradiative decay of DNS. This conclusion is supported by TDDFT calculations on DNS-B3 in dichloromethane. The structure at the conical intersection for internal conversion is associated with not only a twisting but also a pyramidalization of the nitro group. The mechanism of the NO2 torsion is discussed in terms of the effects of solvent polarity, the substituents, and the volume demand. The differences and analogies of the NO2- vs amino-twisted intramolecular charge-transfer (TICT) state of trans-aminostilbenes are also discussed.

  10. Electrorheological characterization of dispersions in silicone oil of encapsulated liquid crystal 4-n-penthyl-4‧-cyanobiphenyl in polyvinyl alcohol and in silica

    NASA Astrophysics Data System (ADS)

    Brehm, T.; Pereira, G.; Leal, C. R.; Gonçalves, C.; Borges, J. P.; Cidade, M. T.

    2015-03-01

    The electrorheological (ER) effect is known as the change in the apparent viscosity upon the application of an external electric field perpendicular to the flow direction. In this work we present the electrorheological behaviour of suspensions in silicone oil of two different dispersed phases: foams of liquid crystal 4-n-penthyl-4‧-cyanobiphenyl (5CB) encapsulated in polyvinyl alcohol (PVA) and nano/microspheres of 5CB encapsulated in silica. We will present the viscosity curves under the application of an electric field ranging between 0 and 3 kV mm-1. The ER effect was observed for the suspensions of 5CB/PVA but not in the case of 5CB/silica. For the case of the suspensions of 5CB/PVA, the effect of the viscosity of the continuum phase and the concentration of the dispersed phase was analysed, showing that the enhancement of the viscosity of the suspension increases with the concentration, as expected, however the continuum phase viscosity has no significant effect, at least in the investigated viscosity range.

  11. A novel one-step strategy toward ZnMn2O4/N-doped graphene nanosheets with robust chemical interaction for superior lithium storage.

    PubMed

    Wang, Dong; Zhou, Weiwei; Zhang, Yong; Wang, Yali; Wu, Gangan; Yu, Kun; Wen, Guangwu

    2016-01-29

    Ingenious hybrid electrode design, especially realized with a facile strategy, is appealing yet challenging for electrochemical energy storage devices. Here, we report the synthesis of a novel ZnMn2O4/N-doped graphene (ZMO/NG) nanohybrid with sandwiched structure via a facile one-step approach, in which ultrafine ZMO nanoparticles with diameters of 10-12 nm are well dispersed on both surfaces of N-doped graphene (NG) nanosheets. Note that one-step synthetic strategies are rarely reported for ZMO-based nanostructures. Systematical control experiments reveal that the formation of well-dispersed ZMO nanoparticles is not solely ascribed to the restriction effect of the functional groups on graphene oxide (GO), but also to the presence of ammonia. Benefitting from the synergistic effects and robust chemical interaction between ZMO nanoparticles and N-doped graphene nanosheets, the ZMO/NG hybrids deliver a reversible capacity up to 747 mAh g(-1) after 200 cycles at a current density of 500 mA g(-1). Even at a high current density of 3200 mA g(-1), an unrivaled capacity of 500 mAh g(-1) can still be retained, corroborating the good rate capability.

  12. Synthesis, crystal structure, thermal analysis and dielectric properties of [(C4H9)4N]3Bi2Cl9 compound

    NASA Astrophysics Data System (ADS)

    Trigui, W.; Oueslati, A.; Chaabane, I.; Hlel, F.

    2015-07-01

    A new organic-inorganic tri-tetrabutylammonium nonachlorobibismuthate(III) compound was prepared. It was found to crystallize in the monoclinic system (P21/n space group) with the following lattice parameters: a=11.32(2) Å, b=22.30(3) Å, c=28.53(2) Å and β=96.52(0)°. The [Bi2Cl9]3- anions are surrounded by six [(C4H9)N]+ cations, forming an octahedral configuration. These octahedra are sharing corners in order to provide the tri-dimensional network cohesion. The differential scanning calorimetry reveals four order-disorder reversible phase transitions located at 214, 238, 434 and 477 K. The Raman and infrared spectra confirm the presence of both cationic [(C4H9)N]+ and anionic [Bi2Cl9]3- parts. The dielectric parameters, real and imaginary dielectric permittivity (ε‧ and ε″), and dielectric loss tangent (tg δ), were measured in the frequency range of 209 kHz-5 MHz at different temperatures. The variations of dielectric dispersion (ε') and dielectric absorption (ε″) with frequency show a distribution of relaxation times, which is probably related to the change in the dynamical state of the [(C4H9)4N]+ cations and the [Bi2Cl9]3- anions.

  13. Photodynamic Action Mechanism Mediated by Zinc(II) 2,9,16,23-Tetrakis[4-(N-methylpyridyloxy)]phthalocyanine in Candida albicans Cells.

    PubMed

    Di Palma, María Albana; Alvarez, María Gabriela; Durantini, Edgardo N

    2015-01-01

    The photoreaction type I/type II pathways mediated by zinc(II) 2,9,16,23-tetrakis[4-(N-methylpyridyloxy)]phthalocyanine (ZnPPc(4+) ) was studied in Candida albicans cells. This photosensitizer was strongly bound to C. albicans cells at short times. After 30 min irradiation, 5 μM ZnPPc(4+) produced ~5 log decrease in cell viability. Different probes were used to detect reactive oxygen species (ROS) in cell suspensions (~10(6) CFU mL(-1) ). Singlet molecular oxygen, O2 ((1) Δg ), was observed by the reaction with 9,10-dimethylanthracene (DMA) and tetrasodium 2,2-(anthracene-9,10-diyl)bis(methylmalonate) (ABMM), whereas the nitro blue tetrazolium (NBT) method was used to sense superoxide anion radical (O2·-). Moreover, the effects produced by an anoxic atmosphere and cell suspensions in D2 O, as well as the addition of sodium azide and mannitol as ROS trapping were evaluated in the PDI of C. albicans. These investigation indicates that O2 ((1) Δg ) is generated in the cells, although a minor extension other radical species can also be involved in the PDI of C. albicans mediated by ZnPPc(4+) . PMID:26108811

  14. Cross section limits for the {sup 248}Cm({sup 25}Mg,4n-5n){sup 268,269}Hs reactions

    SciTech Connect

    Dvorak, J.; Dvorakova, Z.; Schuber, R.; Tuerler, A.; Yakushev, A.; Bruechle, W.; Duellmann, Ch. E.; Jaeger, E.; Schaedel, M.; Schausten, B.; Schimpf, E.; Eberhardt, K.; Thoerle, P.; Eichler, R.; Nagame, Y.; Qin, Z.; Semchenkov, A.; Wegrzecki, M.

    2009-03-15

    We report on an attempt to produce and detect {sup 268}Hs and {sup 269}Hs in the nuclear fusion reaction {sup 25}Mg+{sup 248}Cm using the gas phase chemistry apparatus COMPACT. No decay chains attributable to the decay of hassium isotopes were observed during the course of this experiment. From the nonobservation of {sup 269}Hs we derive a cross section limit of 0.4 pb (63% confidence limit) for the reaction {sup 248}Cm({sup 25}Mg,4n){sup 269}Hs at a center-of-target beam energy of 140 MeV. The evaluated cross section limit for the {sup 248}Cm({sup 25}Mg,5n){sup 268}Hs reaction depends on the assumed half-life of unknown {sup 268}Hs. Current systematics of the half-lives for even-even Hs isotopes suggests a value of 0.5 s, resulting in a cross section limit of 1.3 pb.

  15. Methylated 4-N,N dimethyl aminobenzyl N,O carboxymethyl chitosan as a new chitosan derivative: Synthesis, characterization, cytotoxicity and antibacterial activity.

    PubMed

    Rahmani, Soheila; Mohammadi, Zohreh; Amini, Mohsen; Isaei, Elham; Taheritarigh, Sadegh; Rafiee Tehrani, Niyousha; Rafiee Tehrani, Morteza

    2016-09-20

    Chitosan, as a biocompatible polymer, is very attractive for biomedical applications. Continues studies are performing for improving its physicochemical features in order to make it more suitable for such approaches. In this study, methylated 4-N,N dimethyl aminobenzyl N,O carboxymethyl chitosan (MABCC) was synthesized,as a new chitosan derivative, in three steps. The investigations were carried out using FTIR, NMR, TGA and zeta potential measurement. Antibacterial and cell viability assessments were performed on four bacterial strains and two cell lines respectively. FTIR and NMR results showed that all substitution reactions were successfully carried out. Zeta potential of MABCC at various pH especially alkaline pH was greater than chitosan and it revealed increasing the solubility of the derivative. Antibacterial activity of MABCC was extremely greater than chitosan especially in Gram positive bacteria.Furthermore,it had no significant cytotoxicity against MCF-7 and Skov-3 cell lines in comparison to chitosan. These findings confirm that this new derivative can be introduced as a suitable compound for biomedical purposes.

  16. H-bond length dependence of the distortion in acid tetrahedron groups H nAsO 4 ( n=1-3)

    NASA Astrophysics Data System (ADS)

    Ichikawa, Mizuhiko

    1988-07-01

    The H-bond length O⋯O dependence of the distortions of the AsO 4 tetrahedra of acid arsenate groups H nAsO 4 ( n=1-3) have been studied by examining the correlations of the As sbnd O bond lengths, OAsO angles, O sbnd O lengths and Baur's distortion indices (DI) with O⋯O and comparing them with those of the corresponding H nPO 4 groups previously reported. The behavior of the O⋯O dependence of the AsO 4 distortion is analogous to that of PO 4 distortion as a whole, that is (a) all DI increase with increasing O⋯O, and correspondingly some of the individual or average As sbnd O lengths, OAsO angles and O sbnd O lengths correlate with O⋯O consistently; (b) the overall mean values of As sbnd O, OAsO and O sbnd O are reasonably constant in each H nAsO 4 type, most notably in the case of OAsO. The dependence of the PO 4 distortion on O⋯O can be described approximately by a model in which the P atom shifts away from the centroid of the regular tetrahedral framework, but the O⋯O dependence of the AsO 4 distortion is more complicated.

  17. Low Temperature Heat Capacities and Standard Molar Enthalpy of Formation of 2-Pyrazinecarboxylic Acid (C5H4N2O2)(s).

    PubMed

    Kong, Yu-Xia; Di, You-Ying; Yang, Wei-Wei; Gao, Sheng-Li; Tan, Zhi-Cheng

    2010-06-01

    Low-temperature heat capacities of 2-pyrazinecarboxylic acid (C5H4N2O2)(s) were measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial equation of heat capacities as a function of temperature was fitted by least squares method. Based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15 K were calculated and tabulated at 10 K intervals. The constant-volume energy of combustion of the compound at T = 298.15 K was measured by a precision rotating-bomb combustion calorimeter to be ΔcU = -(17839.40 ± 7.40) J g-1. The standard molar enthalpy of combustion of the compound was determined to be ΔcH0m = -(2211.39 ± 0.92) KJ mol-1, according to the definition of combustion enthalpy. Finally, the standard molar enthalpy of formation of the compound was calculated to be ΔfH0m = -(327.82 ± 1.13) kJ mol-1 in accordance with Hess law. PMID:24061733

  18. beta1,4-N-Acetylglucosaminyltransferase III potentiates beta1 integrin-mediated neuritogenesis induced by serum deprivation in Neuro2a cells.

    PubMed

    Shigeta, Masaki; Shibukawa, Yukinao; Ihara, Hideyuki; Miyoshi, Eiji; Taniguchi, Naoyuki; Gu, Jianguo

    2006-06-01

    Aspects of the biological significance of the bisecting N-acetylglucosamine (GlcNAc) structure on N-glycans introduced by beta1,4-N-acetylglucosaminyltransferase III (GnT-III) in Neuro2a cell differentiation are demonstrated. The overexpression of GnT-III in the cells led to the induction of axon-like processes with numerous neurites and swellings, in which beta1 integrin was localized, under conditions of serum starvation. This enhancement in neuritogenesis was suppressed by either the addition of a bisecting GlcNAc-containing N-glycan or erythroagglutinating phytohemagglutinin (E(4)-PHA), which preferentially recognizes the bisecting GlcNAc. GnT-III-promoted neuritogenesis was also significantly perturbed by treatment with a functional blocking anti-beta1 integrin antibody. In fact, beta1 integrin was found to be one of the target proteins of GnT-III, as confirmed by a pull-down assay with E(4)-PHA. These data suggest that N-glycans with a bisecting GlcNAc on target molecules, such as beta1 integrin, play important roles in the regulation of neuritogenesis. PMID:16531477

  19. Thiol-reactive Derivatives of the Solvatochromic 4-N,N-Dimethylamino-1,8-naphthalimide Fluorophore: A Highly Sensitive Toolset for the Detection of Biomolecular Interactions

    PubMed Central

    Loving, Galen; Imperiali, Barbara

    2009-01-01

    The solvatochromic fluorophore 4-N,N-dimethylamino-1,8-naphthalimide (4-DMN) possesses extremely sensitive emission properties due largely to the low intrinsic fluorescence it exhibits in polar protic solvents like water. This makes it well suited as a probe for the detection of a wide range of biomolecular interactions. Herein we report the development and evaluation of a new series of thiol-reactive agents derived from this fluorophore. The members of this series vary according to linker type and the electrophilic group required for the labeling of proteins and other biologically relevant molecules. Using the calcium-binding protein calmodulin as a model system, we compare the performance of the 4-DMN derivatives to that of several commercially available solvatochromic fluorophores identifying many key factors import to the successful application of such tools. This study also demonstrates the power of this new series of labeling agents by yielding a fluorescent calmodulin construct capable of producing a greater than 100-fold increase in emission intensity upon binding to calcium. PMID:19821578

  20. Methylated 4-N,N dimethyl aminobenzyl N,O carboxymethyl chitosan as a new chitosan derivative: Synthesis, characterization, cytotoxicity and antibacterial activity.

    PubMed

    Rahmani, Soheila; Mohammadi, Zohreh; Amini, Mohsen; Isaei, Elham; Taheritarigh, Sadegh; Rafiee Tehrani, Niyousha; Rafiee Tehrani, Morteza

    2016-09-20

    Chitosan, as a biocompatible polymer, is very attractive for biomedical applications. Continues studies are performing for improving its physicochemical features in order to make it more suitable for such approaches. In this study, methylated 4-N,N dimethyl aminobenzyl N,O carboxymethyl chitosan (MABCC) was synthesized,as a new chitosan derivative, in three steps. The investigations were carried out using FTIR, NMR, TGA and zeta potential measurement. Antibacterial and cell viability assessments were performed on four bacterial strains and two cell lines respectively. FTIR and NMR results showed that all substitution reactions were successfully carried out. Zeta potential of MABCC at various pH especially alkaline pH was greater than chitosan and it revealed increasing the solubility of the derivative. Antibacterial activity of MABCC was extremely greater than chitosan especially in Gram positive bacteria.Furthermore,it had no significant cytotoxicity against MCF-7 and Skov-3 cell lines in comparison to chitosan. These findings confirm that this new derivative can be introduced as a suitable compound for biomedical purposes. PMID:27261738

  1. A simple and sensitive method for the determination of 4-n-octylphenol based on multi-walled carbon nanotubes modified glassy carbon electrode.

    PubMed

    Zheng, Qiaoli; Yang, Ping; Xu, He; Liu, Jianshe; Jin, Litong

    2012-01-01

    A simple and sensitive electroanalytical method was presented for the determination of 4-n-octylphenol (OP) based on multi-walled carbon nanotubes (MWCNTs) modified glassy carbon electrode (GCE). OP was directly oxidized on the MWCNTs/GCE, and the electrochemical oxidation mechanism was demonstrated by a one-electron and one-proton process in the reaction. The oxidation peak current of OP was significantly enhanced by the use of MWCNTs/GCE compared with those of bare glassy carbon electrode, suggesting that the modified electrode can remarkably improve the performance for OP determination. Factors influencing the detection processes were optimized. Under these optimal conditions, a linear relationship between concentration of OP and current response was obtained in the range of 5 x 10(-8) to 1 x 10(-5) mol/L with a detection limit of 1.5 x 10(-8) mol/L and correlation coefficient 0.9986. The modified electrode showed good selectivity, sensitivity, reproducibility and high stability.

  2. Synthesis, crystal structure, NMR study and AC conductivity of [(C3H7)4N]2Cd2ClF5 compound

    NASA Astrophysics Data System (ADS)

    Hajji, Rachid; Oueslati, Abderrazak; Body, Monique; Hlel, Faouzi

    2015-08-01

    The [(C3H7)4N]2Cd2ClF5 compound was crystallized in the triclinic system with space group P1. The crystal structure consists of organic-inorganic layers, stacked along direction. The organic part consists of two cations types. The inorganic layer is made up of Cd2ClF5 dimmers composed of two in-equivalent irregular tetrahedra sharing one edge (Cl-F). The MAS NMR spectra showed two, three and five isotropic resonances relative to 111Cd, 13C and 19F nuclei, respectively. DSC measurement disclosed a phase transition at around 380 K. The impedance spectroscopy and AC electrical conductivity measurements of our compound were taken from 209 Hz to 5 MHz over the temperature range of 350-381 K. Nyquist plots ( Z″ vs Z') show semicircle arcs at different temperatures, and an electrical equivalent circuit has been proposed to explain the impedance results. The circuits consist of the parallel combination of bulk resistance ( R), capacitance ( C) and fractal capacitance (CPE). The conductivity σ p follows the Arrhenius relation. The near value of activation energies obtained from the conductivity data and circuit equivalent confirms that the transport is through hopping mechanism. The analysis of the experimental data shows that the reorientation motion of [N(C3H7)4]+ cations and/or [Cd2ClF5]2- anions is probably responsible for the observed conductivity.

  3. Raman study of order-disorder phase transition in [(C3H7)4N]3Bi3Cl12 compound

    NASA Astrophysics Data System (ADS)

    Trigui, W.; Oueslati, A.; Hlel, F.; Bulou, A.

    2016-02-01

    The [(C3H7)4N]3Bi3Cl12 compound that crystallizes at room temperature in a centrosymmetric triclinic system (P1bar space group) is studied on heating up to its melting temperature. Differential scanning calorimetry investigations disclosed an irreversible phase transition at T = 414 K. Raman scattering studies (140-3500 cm-1) were investigated in the temperature range 398-438 K. A detailed analysis of the frequency, half-width and reduced intensity of the bands associated to υ(Bi-Cl) (at 254 cm-1), υ(Bi-Cl) (at 287 cm-1) and υs(N-C-C)+δs(C-N-C) (at 1034 cm-1) is quantitatively described in term of an order-disorder phase transitions. The temperature dependence of the correlation lengths of these three bands is consistent with a disordered state at high temperature. This behavior is presumably governed by the reorientational motion of the alkylammonium chains of the cations between two sites coupled with changes of interactions with the anionic groups.

  4. Influence of aeration on CH4, N2O and NH3 emissions during aerobic composting of a chicken manure and high C/N waste mixture.

    PubMed

    Shen, Yujun; Ren, Limei; Li, Guoxue; Chen, Tongbin; Guo, Rui

    2011-01-01

    Co-composting of chicken manure, straw and dry grasses was investigated in a forced aeration system to estimate the effect of aeration rates on NH(3), CH(4) and N(2)O emissions and compost quality. Continuous measurements of gas emissions were carried out and detailed gas emission patterns were obtained using an intermittent-aeration of 30 min on/30 min off at rates of 0.01 (A1), 0.1 (A2) and 0.2 (A3) m(3)min(-1)m(-3). Concentrations of CH(4) and N(2)O at the low aeration rate (A1) were significantly greater than those at the other two rates, but there was no significant difference between the A2 and A3 treatments. CH(4) and N(2)O emissions for this mixture could be controlled when the composting process was aerobic and ammonia emissions were reduced at a lower aeration rate. Comparison of CH(4), N(2)O, NH(3) emissions and compost quality showed that the aeration rate of the A2 treatment was superior to the other two aeration rates. PMID:20888749

  5. Conversion of 4-N,N-dimethylamino-4’-N’-methyl-stilbazolium tosylate (DAST) from a Simple Optical Material to a Versatile Optoelectronic Material

    PubMed Central

    Xu, Xiangdong; Sun, Ziqiang; Fan, Kai; Jiang, Yadong; Huang, Rui; Wen, Yuejiang; He, Qiong; Ao, Tianhong

    2015-01-01

    4-N,N-dimethylamino-4’-N’-methyl-stilbazolium tosylate (DAST) is an important optical material, but its poor conductivity limits applications in devices. To tackle this problem, we designed, prepared, and systematically investigated novel binary composite films that are composed of two-dimensional (2D) DAST and 2D graphene. Results indicate that both electrical and optical properties of DAST can be significantly improved by graphene addition. The negative steric effects of big DAST molecules that greatly trouble ex-situ synthesis can be efficiently overcome by in-situ synthesis, thus leading to better film quality and higher physical properties. Consequently, the in-situ composite film exhibits a low sheet resistance of 7.5 × 106 ohm and high temperature coefficient of resistance of −2.79% K−1, close to the levels of the most important bolometric materials for uncooled infrared detectors. Particularly, a new low temperature reduction of graphene oxide induced by DAST, which is further enhanced by in-situ process, was discovered. This work presents valuable information about the DAST–graphene composite films, their chemical structures, mechanisms, physical properties, and comparison on in-situ and ex-situ syntheses of graphene–based composites, all of which will be helpful for not only theoretically studying the DAST and graphene materials and expanding their applications, but also for seeking new optoelectronic sensitive materials. PMID:26192068

  6. Crystal structure of the human CD4 N-terminal two-domain fragment complexed to a class II MHC molecule.

    SciTech Connect

    Wang, J.-H.; Meijers, R.; Xiong, Y.; Liu, J.-H.; Sakihama, T.; Zhang, R.-G.; Joachimiak, A.; Reinherz, E. L.; Biosciences Division; Dana-Farber Cancer Inst.; Harvard Medical School

    2001-09-11

    The structural basis of the interaction between the CD4 coreceptor and a class II major histocompatibility complex (MHC) is described. The crystal structure of a complex containing the human CD4 N-terminal two-domain fragment and the murine I-A{sup k }class II MHC molecule with associated peptide (pMHCII) shows that only the 'top corner' of the CD4 molecule directly contacts pMHCII. The CD4 Phe-43 side chain extends into a hydrophobic concavity formed by MHC residues from both {alpha}2 and {beta}2 domains. A ternary model of the CD4-pMHCII-T-cell receptor (TCR) reveals that the complex appears V-shaped with the membrane-proximal pMHCII at the apex. This configuration excludes a direct TCR-CD4 interaction and suggests how TCR and CD4 signaling is coordinated around the antigenic pMHCII complex. Human CD4 binds to HIV gp120 in a manner strikingly similar to the way in which CD4 interacts with pMHCII. Additional contacts between gp120 and CD4 give the CD4-gp120 complex a greater affinity. Thus, ligation of the viral envelope glycoprotein to CD4 occludes the pMHCII-binding site on CD4, contributing to immunodeficiency.

  7. Measurements of CH4, N2O, CO, H2O and O3 in the middle atmosphere by the ATMOS experiment on Spacelab 3

    NASA Technical Reports Server (NTRS)

    Gunson, M. R.; Farmer, C. B.; Norton, R. H.; Zander, R.; Rinsland, C. P.; Shaw, J. H.; Gao, Bo-Cai

    1989-01-01

    The volume mixing ratios of five minor gases (CH4, N2O, CO, H2O, and O3) were retrieved through the middle atmosphere from the analysis of 0.01/cm resolution infrared solar occultation spectra recorded near 28 N and 48 S latitudes with the ATMOS (Atmospheric Trace Molecule Spectroscopy) instrument, flown on board Spacelab 3. The results, which constitute the first simultaneous observations of continuous profiles through the middle atmosphere for these gases, are in general agreement with reported measurements from ground, balloon and satellite-based instruments for the same seasons. In detail, the vertical profiles of these gases show the effects of the upper and middle atmospheric transport patterns dominant during the season of these observations. The profiles inferred at different longitudes around 28 N suggest a near-uniform zonal distribution of these gases. Although based on fewer observations, the sunrise occultation measurements point to a larger variability in the vertical distribution of these gases at 48 S.

  8. Seasonal changes of CO2, CH4, N2O, and SF6 in the upper troposphere/lower stratosphere over the Eurasian continent observed by commercial airliner

    NASA Astrophysics Data System (ADS)

    Sawa, Yousuke; Machida, Toshinobu; Matsueda, Hidekazu; Niwa, Yosuke; Tsuboi, Kazuhiro; Murayama, Shohei; Morimoto, Shinji; Aoki, Shuji

    2015-03-01

    The seasonal variations of greenhouse gases at about 11 km altitude were analyzed from monthly air samples collected aboard a commercial airliner flying between Europe and Japan from April 2012 to March 2014. Compared to lower latitudes, the upper troposphere between 50 and 70°N showed higher CH4 and SF6 and an earlier seasonal phase of CO2. However, N2O values were similar to those in the subtropics. CH4, N2O, and SF6 in the lower stratosphere with potential temperature of up to 50 K above the tropopause showed seasonal variations with maxima in November/December and minima in April/May. At potential temperatures of 37.5-50 K above the tropopause, SF6 age was estimated to be about 22 months in May and 9 months in November. This strong seasonal variation is explained by the subsidence of high-stratospheric air in spring and the effective flushing of the lowermost stratospheric air with tropospheric air in autumn.

  9. Macrocyclic Se4N2[7,7]ferrocenophane and Se2N[10]ferrocenophane containing benzyl unit: synthesis, complexation, crystal structures, electrochemical and optical properties.

    PubMed

    Qu, Jian; Song, Yinglin; Ji, Wei; Jing, Su; Zhu, Dunru; Huang, Wei; Zheng, Mengxi; Li, Yanle; Ma, Jing

    2016-02-28

    Two novel macrocyclic polyselena[n]ferrocenophanes containing a pendent benzyl unit, 20-membered Se4N2[7,7]ferrocenophane (L1) and 10-membered Se2N[10]ferrocenophane (L2), were designed and synthesized. The reaction of L1 with two molar amounts of metal salts (M = Cu(+), Cu(2+), Pd(2+) and Hg(2+)) led to six dimetallic complexes 1-6. A crystallographic study revealed that each metal center in 1-5 was tetracoordinated to two selenium atoms from different ferrocene units, one aliphatic nitrogen atom and one co-ligand. The structures of the complexes contain a two-fold axis perpendicular to the molecular plane with two pendant benzyl moieties in an anti-conformation. Macrocycle L1 gives significant electrochemical, linear and third-order nonlinear optical responses to Cu(2+) and Hg(2+). The DFT/B3LYP calculations of 4 demonstrated a small HOMO-LUMO energy gap and delocalization of the π-electron cloud in the frontier molecular orbitals, which led to the enhancement of molecular NLO properties after complexation. The results show that the oxidation state of the ferrocene unit is accompanied by significant differences in the corresponding absorption spectra and third-order NLO properties. PMID:26790582

  10. External Electric Field Effects on Excited-State Intramolecular Proton Transfer in 4'-N,N-Dimethylamino-3-hydroxyflavone in Poly(methyl methacrylate) Films.

    PubMed

    Furukawa, Kazuki; Hino, Kazuyuki; Yamamoto, Norifumi; Awasthi, Kamlesh; Nakabayashi, Takakazu; Ohta, Nobuhiro; Sekiya, Hiroshi

    2015-09-17

    The external electric field effects on the steady-state electronic spectra and excited-state dynamics were investigated for 4'-N,N-(dimethylamino)-3-hydroxyflavone (DMHF) in a poly(methyl methacrylate) (PMMA) film. In the steady-state spectrum, dual emission was observed from the excited states of the normal (N*) and tautomer (T*) forms. Application of an external electric field of 1.0 MV·cm(-1) enhanced the N* emission and reduced the T* emission, indicating that the external electric field suppressed the excited-state intramolecular proton transfer (ESIPT). The fluorescence decay profiles were measured for the N* and T* forms. The change in the emission intensity ratio N*/T* induced by the external electric field is dominated by ESIPT from the Franck-Condon excited state of the N* form and vibrational cooling in potential wells of the N* and T* forms occurring within tens of picoseconds. Three manifolds of fluorescent states were identified for both the N* and T* forms. The excited-state dynamics of DMHF in PMMA films has been found to be very different from that in solution due to intermolecular interactions in a rigid environment.

  11. A novel one-step strategy toward ZnMn2O4/N-doped graphene nanosheets with robust chemical interaction for superior lithium storage

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Zhou, Weiwei; Zhang, Yong; Wang, Yali; Wu, Gangan; Yu, Kun; Wen, Guangwu

    2016-01-01

    Ingenious hybrid electrode design, especially realized with a facile strategy, is appealing yet challenging for electrochemical energy storage devices. Here, we report the synthesis of a novel ZnMn2O4/N-doped graphene (ZMO/NG) nanohybrid with sandwiched structure via a facile one-step approach, in which ultrafine ZMO nanoparticles with diameters of 10-12 nm are well dispersed on both surfaces of N-doped graphene (NG) nanosheets. Note that one-step synthetic strategies are rarely reported for ZMO-based nanostructures. Systematical control experiments reveal that the formation of well-dispersed ZMO nanoparticles is not solely ascribed to the restriction effect of the functional groups on graphene oxide (GO), but also to the presence of ammonia. Benefitting from the synergistic effects and robust chemical interaction between ZMO nanoparticles and N-doped graphene nanosheets, the ZMO/NG hybrids deliver a reversible capacity up to 747 mAh g-1 after 200 cycles at a current density of 500 mA g-1. Even at a high current density of 3200 mA g-1, an unrivaled capacity of 500 mAh g-1 can still be retained, corroborating the good rate capability.

  12. Prognostic Value of Microvascular Density in Dukes A and B (T1–T4, N0, M0) Colorectal Carcinomas

    PubMed Central

    Uribarrena A, Rafael; Ortego, Javier; Fuentes, Javier; Raventós, Nuria; Parra, Pilar; Uribarrena E, Rafael

    2009-01-01

    Background. Aproximatelly 30% of patients operated on for colorectal cancer (CRC), with an expectedly favourable prognosis (Dukes A-B/T1–T4, N0, M0) suffer recurrence and/or die. Method. In order to determine if tumor microvascular density (MVD) is a prognostic factor in CRC, samples from tumors of 104 Dukes A-B CRC patients were retrospectively studied. Immunohistochemistry was performed for anti-CD34 antibody to visualize tumor vascularisation. MVD was expressed as the total number of vessels and as the percentage of microvascular area. We calculated MVD with a morphometry program and performed descriptive, bivariate, and survival statistics. Results. The mean number of vessels was 37.37/200x field, and the mean vascular area was the 3.972%. 30% of the patients with < 37 vessels/field, and 21% of the patients with > 37 vessels/field, experienced recurrence/death. The 35% of patients with < 4% of vascular area died following recurrence, compared with 14% of patients with ≥4% of vascular area. These differences in % of vascular area were statistically significant. Conclusion. MVD expressed as the total number of vessels had no a statistically significant influence on the evolution of CRC. However, neoplasias with a greater % of vascular were associated to a better outcome. PMID:19902004

  13. Relationship between molecular stacking and optical properties of 9,10-bis((4-N,N-dialkylamino)styryl) anthracene crystals: the cooperation of excitonic and dipolar coupling.

    PubMed

    Li, Feng; Gao, Na; Xu, Hai; Liu, Wei; Shang, Hui; Yang, Wenjun; Zhang, Ming

    2014-08-01

    Five 9,10-bis((4-N,N-dialkylamino)styryl) anthracene derivatives (DSA-C1-DSA-C7) with different length alkyl chains were synthesized. They showed the same color in dilute solutions but different colors in crystals. The absorption, photoluminescence, and fluorescence decay indicate that there exist both excitonic and dipolar coupling in crystals of DSA-C1-DSA-C7. X-ray crystallographic analysis revealed that all the crystals belong to the triclinic space group P1 with one molecule per unit cell and that the molecules in every crystal have the identical orientation. This offers ideal samples to investigate the impact of the molecular stacking on the optical properties of the crystals. For the first time, the cooperation of excitonic and dipolar coupling has been comprehensively studied, and the contribution to the spectral shift from the excitonic and dipolar couplings quantitatively obtained. The experiments of amplified spontaneous emission (ASE) together with measurements of the quantum efficiency further confirmed this interpretation. The results suggest that the excitonic and dipolar couplings between the adjacent molecules are both important and jointly induce the spectral shifts of the crystals.

  14. Comparative study of the electrical properties of Au/n-Si (MS) and Au/Si3N4/n-Si (MIS) Schottky diodes

    NASA Astrophysics Data System (ADS)

    Adem, Tataroğlu

    2013-06-01

    In this paper, the electrical parameters of Au/n-Si (MS) and Au/Si3N4/n-Si (MIS) Schottky diodes are obtained from the forward bias current—voltage (I—V) and capacitance—voltage (C—V) measurements at room temperature. Experimental results show that the rectifying ratios of the MS and MIS diodes at ± 5 V are found to be 1.25 × 103 and 1.27 × 104, respectively. The main electrical parameters of the MS and MIS diodes, such as the zero-bias barrier height (ΦBo) and ideality factor (n), are calculated to be 0.51 eV (I—V), 0.53 eV (C—V), and 4.43, and 0.65 eV (I—V), 0.70 eV (C—V), and 3.44, respectively. In addition, the energy density distribution profile of the interface states (Nss) is obtained from the forward bias I—V, and the series resistance (Rs) values for the two diodes are calculated from Cheung's method and Ohm's law.

  15. Lessons from the gonadotropin-regulated long chain acyl-CoA synthetase (GR-LACS) null mouse model: a role in steroidogenesis, but not result in X-ALD phenotype.

    PubMed

    Sheng, Yi; Tsai-Morris, Chon-Hwa; Li, Jie; Dufau, Maria L

    2009-03-01

    Gonadotropin-regulated long chain fatty acid Acyl-CoA synthetase (GR-LACS), is a member of the LACS family that is regulated by gonadotropin in the rat Leydig cell (LC). Its mouse/human homologs, lipidosin/bubblegum, have been suggested to participate in X-linked adrenoleukodystrophy (X-ALD), an adreno/neurodegenerative disorder with accumulation of very long chain fatty acids (VLCFA) in tissues and plasma. To further gain insights into its regulatory function, a GR-LACS/lipidosin null mouse was generated. No apparent phenotypic abnormalities were observed in the X-ALD target tissues (brain, testis, adrenal). Nuclear inclusions seen in mice >15 month-old, were present in LC of 9 month-old GR-LACS(-/-) mice. LC of the null mice showed refractoriness to the gonadotropin-induced desensitization of testosterone production that is observed in adult animals. LCFAs were moderately increased in the testis, ovary and brain, but not in the adrenal gland of GR-LACS(-/-) mice, with no major changes in VLCFA. No change in LACS activity was observed in these tissues, suggesting a compensatory mechanism exhibited by other LACS members. The GR-LACS(-/-) model did not support its association with X-ALD. These studies revealed a role of GR-LACS in reducing the aging process of the LC, and its participation in gonadotropin-induced testicular desensitization of testosterone production.

  16. Ring-strain release in neutral and dicationic 7,8,17,18-tetra-bromo-5,10,15,20-tetra-phenyl-porphyrin: crystal structures of C44H26Br4N4 and C44H28Br4N4 (2+)·2ClO4 (-)·3CH2Cl2.

    PubMed

    Scheidt, W Robert; Duval, Hugues F; Oliver, Allen G

    2016-06-01

    Two porphyrin complexes were studied to determine the effects of protonation on ring deformation within the porphyrin. The porphyrin 7,8,17,18-tetra-bromo-5,10,15,20-tetra-phenyl-porphyrin, C44H26Br4N4, was selected because the neutral species is readily doubly protonated to yield a dication, which was crystallized here with perchlorate counter-ions as a di-chloro-methane tris-olvate, C44H28Br4N4 (2+)·2ClO4 (-)·3CH2Cl2. The centrosymmetric neutral species is observed to have a mild 'ruffling' of the pyrrole rings and is essentially planar throughout; intra-molecular N-H⋯N hydrogen bonds occur. In contrast, the dication exhibits considerable deformation, with the pyrrole rings oriented well out of the plane of the porphyrin, resulting in a 'saddle' conformation of the ring. The charged species forms N-H⋯O hydrogen bonds to the perchlorate anions, which lie above and below the plane of the porphyrin ring. Distortions to the planarity of the pyrrole rings in both cases are very minor. The characterization of the neutral species represents a low-temperature redetermination of the previous room-temperature analyses [Zou et al. (1995 ▸). Acta Cryst. C51, 760-761; Rayati et al. (2008 ▸). Polyhedron, pp. 2285-2290], which showed disorder and physically unrealistic displacement parameters. PMID:27308051

  17. Determining intensive parameters through clinopyroxene-liquid equilibrium in Grímsvötn 2011 and Bárðarbunga 2014 basalts.

    NASA Astrophysics Data System (ADS)

    Haddadi, Baptiste; Sigmarsson, Olgeir; Devidal, Jean-Luc

    2015-04-01

    Pressure (P) and temperature (T) at which magma is stored before eruption are parameters needed for better understanding of pre-eruptive signals. Putirka (2008) reviewed various igneous geothermobarometers based on crystal-liquid equilibrium. These allow evaluating early melt inclusion (MI) entrapment conditions and final crystal-matrix glass P-T equilibrium conditions. In this study, the former is based on clinopyroxene (cpx)-hosted MI and cpx-host measurements, whereas the latter is estimated from analyses of crystal rims and adjacent matrix glass. Olivine (ol)-liquid equilibrium is rapidly attained and records the last thermal equilibrium before basalt eruptions. In contrast, more sluggish reaction between cpx and liquid makes MI in cpx cores the choice for estimating the deepest (and hottest) crystal-liquid equilibrium. Equilibrium criteria were evaluated from the apparent Fe-Mg exchange and textural relationships. Tephra erupted at Grímsvötn central volcano 2011 is of quartz tholeiite composition whereas the 2014 tephra from Bárðarbunga volcanic system is a more primitive olivine tholeiite. These two basalt types are the most common in Iceland and form a crust with estimated density of 2800 kg/m3. Both basalts contain approximately 1-5% phenocrysts of plagioclases, cpx and ol with sparse sulphides and, in the Grímsvötn case, ubiquitous FeTi-oxides. The geothermobarometers suggest that cpx crystallized at P from 60 to 620 MPa (depth range: 1.7-17 km) and T between 1030 and 1135 °C before the Grímsvötn 2011 eruption. In marked contrast, the Bárðarbunga ol-tholeiite crystallized at higher P from 410 to 660 MPa (depth range: 11-18 km) at restricted T of 1176 to 1182 °C. The shallowest recorded crystallization depth at Grímsvötn coincides with geophysical depth estimates of its high-level magma chamber (1.8 km; Hreinsdóttir et al., 2014), whereas the deepest crystallization is within error of the estimated mantle-crust boundary, as also observed for

  18. Probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 exhibit strong antifungal effects against vulvovaginal candidiasis-causing Candida glabrata isolates

    PubMed Central

    Chew, SY; Cheah, YK; Seow, HF; Sandai, D; Than, LTL

    2015-01-01

    Aims This study investigates the antagonistic effects of the probiotic strains Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 against vulvovaginal candidiasis (VVC)-causing Candida glabrata. Methods and Results Growth inhibitory activities of Lact. rhamnosus GR-1 and Lact. reuteri RC-14 strains against C. glabrata were demonstrated using a spot overlay assay and a plate-based microtitre assay. In addition, these probiotic lactobacilli strains also exhibited potent candidacidal activity against C. glabrata, as demonstrated by a LIVE/DEAD yeast viability assay performed using confocal laser scanning microscopy. The metabolic activities of all C. glabrata strains were completely shut down in response to the challenges by the probiotic lactobacilli strains. In addition, both probiotic lactobacilli strains exhibited strong autoaggregation and coaggregation phenotypes in the presence of C. glabrata, which indicate that these lactobacilli strains may exert their probiotic effects through the formation of aggregates and, thus the consequent prevention of colonization by C. glabrata. Conclusions Probiotic Lact. rhamnosus GR-1 and Lact. reuteri RC-14 strains exhibited potent antagonistic activities against all of the tested C. glabrata strains. These lactobacilli exhibited antifungal effects, including those attributed to their aggregation abilities, and their presence caused the cessation of growth and eventual cell death of C. glabrata. Significance and Impact of the Study This is the first study to report on the antagonistic effects of these probiotic lactobacilli strains against the non-Candida albicans Candida (NCAC) species C. glabrata. PMID:25688886

  19. α-Lipoic acid attenuates LPS-induced liver injury by improving mitochondrial function in association with GR mitochondrial DNA occupancy.

    PubMed

    Liu, Zhiqing; Guo, Jun; Sun, Hailin; Huang, Yanping; Zhao, Ruqian; Yang, Xiaojing

    2015-09-01

    α-Lipoic acid (LA) has been demonstrated to be a key regulator of energy metabolism. However, whether LA can protect the liver from inflammation, as well as the underlying mechanism involved, are still largely unclear. In the present study, mice treated with lipopolysaccharide (LPS) and injected with LA were used as a model. Liver injury, energy metabolism and mitochondrial regulation were investigated to assess the protective effect of LA on the liver and explore the possible mechanisms involved. Our results showed that LA attenuated liver injury, as evidenced by the decreased plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels after LA treatment compared with the LPS-treated group. The hepatic ATP and NADH levels, expression levels of most mitochondrial DNA (mtDNA)-encoded genes as well as mitochondrial complex I, IV and V activities were all significantly increased in the LA-treated group compared with the LPS-treated group. Levels of Sirt3 protein, which is essential for the regulation of mitochondrial metabolism, were also increased in the LA-treated group. Regarding the regulation of mtDNA-encoded genes expression, we observed no obvious change in the methylation status of the mtDNA D-loop region. However, compared to the LPS-treated group, LA treatment increased glucocorticoid receptor (GR) protein expression in the liver, as well as the level of GR occupancy on the mtDNA D-loop region. Our study demonstrates that LA exerts a liver-protective effect in an inflammation state by improving mitochondrial function. Furthermore, to the best of our knowledge, we demonstrate for the first time that GR may be involved in this effect via an enhanced binding to the mtDNA transcriptional control region, thereby regulating the expression of mtDNA-encoded genes. PMID:26133658

  20. Deformation of Grímsvötn volcano, Iceland, 1992-2014: Constraints on magma flow in relation to eruptions in 1998, 2004 and 2011

    NASA Astrophysics Data System (ADS)

    Sigmundsson, Freysteinn; Hreinsdottir, Sigrun; Sturkell, Erik; Ofeigsson, Benedikt; Einarsson, Pall; Roberts, Matthew; Grapenthin, Ronni; Villemin, Thierry; Arnadottir, Thora; Geirsson, Halldor

    2014-05-01

    A time series of ground deformation at Grímsvötn volcano, Iceland from 1992 to 2014 reveals deformation due to plate movements, glacial-isostatic uplift in response to the melting of the Vatnajökull ice cap, annual changes due to snow loading and magma movements. GPS measurements have been made at one nunatak, conducted intermittently since 1992 and continuously since 2004. During this period eruptions have occurred at Grímsvötn in 1998, 2004 and 2011. The component of displacement related to magma movements is obtained after the time series are corrected for signals due to other processes. Uplift and displacement away from the caldera occurs between eruptions at a rate of few cm/yr, interrupted by sudden co-eruptive subsidence and displacement towards the caldera (up to half a meter). This inflation/deflation pattern suggests deformation driven by pressure change in an upper crustal magma chamber, similar to other highly active calderas in Iceland such as Askja and Krafla. A simple model of pressure change variation in a magma chamber at shallow depth, with variable inflow between eruptions and outflow during eruptions can explain the observed deformation pattern. The erupted volume of magma in the 2011 eruption is about 10 times larger than the inferred co-eruptive volume change, attributed to compressibility of magma in the chamber. The magma compressibility is inferred to have remained constant during the 2011 eruption, as about constant scale factor is found during that eruption between eruption rate and displacement rate. This scale factor is, however, about five times lower for the 2004 eruption. This difference implies higher compressibility of magma in the shallow Grímsvötn magma chamber during the 2011 eruption compared to 2004, assuming the active part of the Grimsvötn magma plumbing system remained the same in both eruptions.

  1. [Technical recommendations and best practice guidelines for May-Grünwald-Giemsa staining: literature review and insights from the quality assurance].

    PubMed

    Piaton, Eric; Fabre, Monique; Goubin-Versini, Isabelle; Bretz-Grenier, Marie-Françoise; Courtade-Saïdi, Monique; Vincent, Serge; Belleannée, Geneviève; Thivolet, Françoise; Boutonnat, Jean; Debaque, Hervé; Fleury-Feith, Jocelyne; Vielh, Philippe; Cochand-Priollet, Béatrix; Egelé, Caroline; Bellocq, Jean-Pierre; Michiels, Jean-François

    2015-08-01

    May-Grünwald-Giemsa (MGG) stain is a Romanowsky-type, polychromatic stain as those of Giemsa, Leishman and Wright. Apart being the reference method of haematology, it has become a routine stain of diagnostic cytopathology for the study of air-dried preparations (lymph node imprints, centrifuged body fluids and fine needle aspirations). In the context of their actions of promoting the principles of quality assurance in cytopathology, the French Association for Quality Assurance in Anatomic and Cytologic Pathology (AFAQAP) and the French Society of Clinical Cytology (SFCC) conducted a proficiency test on MGG stain in 2013. Results from the test, together with the review of literature data allow pre-analytical and analytical steps of MGG stain to be updated. Recommendations include rapid air-drying of cell preparations/imprints, fixation using either methanol or May-Grünwald alone for 3-10minutes, two-step staining: 50% May-Grünwald in buffer pH 6.8 v/v for 3-5minutes, followed by 10% buffered Giemsa solution for 10-30minutes, and running water for 1-3minutes. Quality evaluation must be performed on red blood cells (RBCs) and leukocytes, not on tumour cells. Under correct pH conditions, RBCs must appear pink-orange (acidophilic) or buff-coloured, neither green nor blue. Leukocyte cytoplasm must be almost transparent, with clearly delineated granules. However, staining may vary somewhat and testing is recommended for automated methods (slide stainers) which remain the standard for reproducibility. Though MGG stain remains the reference stain, Diff-Quik(®) stain can be used for the rapid evaluation of cell samples. PMID:26188673

  2. Volcanic ash leaching as a means of tracing the environmental impact of the 2011 Grímsvötn eruption, Iceland.

    PubMed

    Cabré, J; Aulinas, M; Rejas, M; Fernandez-Turiel, J L

    2016-07-01

    The Grímsvötn volcanic eruption, from 21 to 28 May, 2011, was the largest eruption of the Grímsvötn Volcanic System since 1873, with a Volcanic Explosivity Index (VEI) of magnitude 4. The main geochemical features of the potential environmental impact of the volcanic ash-water interaction were determined using two different leaching methods as proxies (batch and vertical flow-through column experiments). Ash consists of glass with minor amounts of plagioclase, clinopyroxene, diopside, olivine and iron sulphide; this latter mineral phase is very rare in juvenile ash. Ash grain morphology and size reflect the intense interaction of magma and water during eruption. Batch and column leaching tests in deionised water indicate that Na, K, Ca, Mg, Si, Cl, S and F had the highest potential geochemical fluxes to the environment. Release of various elements from volcanic ash took place immediately through dissolution of soluble salts from the ash surface. Element solubilities of Grímsvötn ash regarding bulk ash composition were <1 %. Combining the element solubilities and the total estimated mass of tephra (7.29 × 10(14) g), the total inputs of environmentally important elements were estimated to be 8.91 × 10(9) g Ca, 7.02 × 10(9) g S, 1.10 × 10(9) g Cl, 9.91 × 10(8) g Mg, 9.91 × 10(8) g Fe and 1.45 × 10(8) g P The potential environmental problems were mainly associated with the release of F (5.19 × 10(9) g).

  3. [Technical recommendations and best practice guidelines for May-Grünwald-Giemsa staining: literature review and insights from the quality assurance].

    PubMed

    Piaton, Eric; Fabre, Monique; Goubin-Versini, Isabelle; Bretz-Grenier, Marie-Françoise; Courtade-Saïdi, Monique; Vincent, Serge; Belleannée, Geneviève; Thivolet, Françoise; Boutonnat, Jean; Debaque, Hervé; Fleury-Feith, Jocelyne; Vielh, Philippe; Cochand-Priollet, Béatrix; Egelé, Caroline; Bellocq, Jean-Pierre; Michiels, Jean-François

    2015-08-01

    May-Grünwald-Giemsa (MGG) stain is a Romanowsky-type, polychromatic stain as those of Giemsa, Leishman and Wright. Apart being the reference method of haematology, it has become a routine stain of diagnostic cytopathology for the study of air-dried preparations (lymph node imprints, centrifuged body fluids and fine needle aspirations). In the context of their actions of promoting the principles of quality assurance in cytopathology, the French Association for Quality Assurance in Anatomic and Cytologic Pathology (AFAQAP) and the French Society of Clinical Cytology (SFCC) conducted a proficiency test on MGG stain in 2013. Results from the test, together with the review of literature data allow pre-analytical and analytical steps of MGG stain to be updated. Recommendations include rapid air-drying of cell preparations/imprints, fixation using either methanol or May-Grünwald alone for 3-10minutes, two-step staining: 50% May-Grünwald in buffer pH 6.8 v/v for 3-5minutes, followed by 10% buffered Giemsa solution for 10-30minutes, and running water for 1-3minutes. Quality evaluation must be performed on red blood cells (RBCs) and leukocytes, not on tumour cells. Under correct pH conditions, RBCs must appear pink-orange (acidophilic) or buff-coloured, neither green nor blue. Leukocyte cytoplasm must be almost transparent, with clearly delineated granules. However, staining may vary somewhat and testing is recommended for automated methods (slide stainers) which remain the standard for reproducibility. Though MGG stain remains the reference stain, Diff-Quik(®) stain can be used for the rapid evaluation of cell samples.

  4. GR 127935 reduces basal locomotor activity and prevents RU 24969-, but not D-amphetamine-induced hyperlocomotion, in the Wistar-Kyoto hyperactive (WKHA) rat.

    PubMed

    Chaouloff, F; Courvoisier, H; Moisan, M P; Mormède, P

    1999-01-01

    The hyperlocomotor effect of the serotonin (5-HT)1A,B receptor agonist 5-methoxy-3-(1,2,3,6-tetrahydro-4-pyridinyl)-1H-indole (RU 24969) has been repeatedly reported. However, 5-HT1A receptors, 5-HT1B receptors (or both) have been claimed to mediate this effect of RU 24969. These contradictory data possibly arise from protocol differences, especially those related to animal species, drugs, and activity assessment. Herein, the influence of a pretreatment with the selective 5-HT1B,D receptor antagonist N-[4-methoxy3-(4-methyl-1-piperazinyl)phenyl]-2'-methyl-4'-(5me thyl-1,2,4-oxadiozol-3-yl)-biphenyl-4-carboxamide (GR 127935; 1, 3.3 and 10 mg/kg IP) on the hyperlocomotor effect of a 5 mg/kg (IP) dose of RU 24969 was studied in Wistar-Kyoto Hyperactive (WKHA) rats. In a first series of experiments, it was confirmed that RU 24969 (2.5 and 5 mg/kg), administered 10 min after the onset of activity recordings, increases locomotion dose-dependently (cage crossings). In a second series of experiments, administration of GR 127935 10 min after the onset of activity recordings promoted a dose-dependent decrease in basal activity (and rearings) and prevented (3.3 and 10 mg/kg) RU 24969-elicited locomotor activity. On the other hand, GR 127935 was ineffective against RU 24969-induced inhibition of rearings. Lastly, it was observed that 3.3 mg/kg GR 127935 did not affect the number of cage crossings and rearings displayed by rats administered 1.5 mg/kg D-amphetamine. This study shows that 5-HT1B receptors play a major role in the hyperlocomotor effect of RU 24969, at least under our experimental setting. Whether these receptors also play a tonic role in the high locomotor activity displayed by WKHA rats remains to be determined.

  5. Detection and Location of Transverse Matrix Cracks in Cross-Ply Gr/Ep Composites Using Acoustic Emission

    NASA Technical Reports Server (NTRS)

    Prosser, W. H.; Jackson, K. E.; Kellas, S.; Smith, B. T.; McKeon, J.; Friedman, A.

    1995-01-01

    Transverse matrix cracking in cross-ply gr/ep laminates was studied with advanced acoustic emission (AE) techniques. The primary goal of this research was to measure the load required to initiate the first transverse matrix crack in cross-ply laminates of different thicknesses. Other methods had been previously used for these measurements including penetrant enhanced radiography, optical microscopy, and audible acoustic microphone measurements. The former methods required that the mechanical test be paused for measurements at load intervals. This slowed the test procedure and did not provide the required resolution in load. With acoustic microphones, acoustic signals from cracks could not be clearly differentiated from other noise sources such as grip damage, specimen slippage, or test machine noise. A second goal for this work was to use the high resolution source location accuracy of the advanced acoustic emission techniques to determine whether the crack initiation site was at the specimen edge or in the interior of the specimen.In this research, advanced AE techniques using broad band sensors, high capture rate digital waveform acquisition, and plate wave propagation based analysis were applied to cross-ply composite coupons with different numbers of 0 and 90 degree plies. Noise signals, believed to be caused by grip damage or specimen slipping, were eliminated based on their plate wave characteristics. Such signals were always located outside the sensor gage length in the gripped region of the specimen. Cracks were confirmed post-test by microscopic analysis of a polished specimen edge, backscatter ultrasonic scans, and in limited cases, by penetrant enhanced radiography. For specimens with three or more 90 degree plies together, there was an exact 1-1 correlation between AE crack signals and observed cracks. The ultrasonic scans and some destructive sectioning analysis showed that the cracks extended across the full width of the specimen. Furthermore, the

  6. Radical Prostatectomy versus External Beam Radiotherapy for cT1-4N0M0 Prostate Cancer: Comparison of Patient Outcomes Including Mortality

    PubMed Central

    Taguchi, Satoru; Fukuhara, Hiroshi; Shiraishi, Kenshiro; Nakagawa, Keiichi; Morikawa, Teppei; Kakutani, Shigenori; Takeshima, Yuta; Miyazaki, Hideyo; Fujimura, Tetsuya; Nakagawa, Tohru; Kume, Haruki; Homma, Yukio

    2015-01-01

    Background Although radical prostatectomy (RP) and external beam radiotherapy (EBRT) have been considered as comparable treatments for localized prostate cancer (PC), it is controversial which treatment is better. The present study aimed to compare outcomes, including mortality, of RP and EBRT for localized PC. Methods We retrospectively analyzed 891 patients with cT1-4N0M0 PC who underwent either RP (n = 569) or EBRT (n = 322) with curative intent at our single institution between 2005 and 2012. Of the EBRT patients, 302 (93.8%) underwent intensity-modulated radiotherapy. Primary endpoints were overall survival (OS) and cancer-specific survival (CSS). Related to these, other-cause mortality (OCM) was also calculated. Biochemical recurrence-free survival was assessed as a secondary endpoint. Cox proportional hazards model was used for multivariate analysis. Results Median follow-up durations were 53 and 45 months, and median ages were 66 and 70 years (P <0.0001), in the RP and EBRT groups, respectively. As a whole, significantly better prognoses of the RP group than the EBRT group were observed for both OS and CSS, although OCM was significantly higher in the EBRT group. There was no death from PC in men with low and intermediate D’Amico risks, except one with intermediate-risk in the EBRT group. In high-risk patients, significantly more patients died from PC in the EBRT group than the RP group. Multivariate analysis demonstrated the RP group to be an independent prognostic factor for better CSS. On the other hand, the EBRT group had a significantly longer biochemical recurrence-free survival than the RP group. Conclusions Mortality outcomes of both RP and EBRT were generally favorable in low and intermediate risk patients. Improvement of CSS in high risk patients was seen in patients receiving RP over those receiving EBRT. PMID:26506569

  7. Nano-crystalline p-ZnGa{sub 2}Te{sub 4}/n-Si as a new heterojunction diode

    SciTech Connect

    Sakr, G.B.; Fouad, S.S.; Yahia, I.S.; Abdel Basset, D.M.; Yakuphanoglu, F.

    2013-02-15

    Graphical abstract: Display Omitted Highlights: ► ZnGa{sub 2}Te{sub 4}/Si thin film was prepared by thermal evaporation technique. ► XRD and AFM graphs support the nano-crystalline of the studied device. ► Dark current–voltage characteristics of the heterojunction diode were investigated. ► Electrical parameters and conduction mechanism were determined. ► Conduction mechanisms were controlled by TE, SCLC and TCLC. -- Abstract: In this communication, ZnGa{sub 2}Te{sub 4} thin film was prepared by thermal evaporation technique on n-Si substrate. P-ZnGa{sub 2}Te{sub 4}/n-Si heterojunction diode was fabricated. The structure of ZnGa{sub 2}Te{sub 4} thin film was checked by XRD pattern and confirmed by AFM micrographs. The dark current–voltage characteristics of the heterojunction diode were investigated to determine the electrical parameters and conduction mechanism as a function of forward and reverse biasing conditions in the range (−10 V to 10 V) at temperature interval (303–423 K). The conduction mechanism was controlled by thermionic emission, space charge limited (SCLC) and trap-charge limited current (TCLC) mechanisms. The basic parameters such as the series resistance R{sub s}, the shunt resistance R{sub sh}, the ideality factor n and the barrier height φ{sub b} of the diode, the total density of trap states N{sub 0} and the exponential trapping distribution P{sub o} were determined. The obtained results showed that ZnGa{sub 2}Te{sub 4} is a good candidate for the applications of electronic devices.

  8. Ring-strain release in neutral and dicationic 7,8,17,18-tetra­bromo-5,10,15,20-tetra­phenyl­porphyrin: crystal structures of C44H26Br4N4 and C44H28Br4N4 2+·2ClO4 −·3CH2Cl2

    PubMed Central

    Scheidt, W. Robert; Duval, Hugues F.; Oliver, Allen G.

    2016-01-01

    Two porphyrin complexes were studied to determine the effects of protonation on ring deformation within the porphyrin. The porphyrin 7,8,17,18-tetra­bromo-5,10,15,20-tetra­phenyl­porphyrin, C44H26Br4N4, was selected because the neutral species is readily doubly protonated to yield a dication, which was crystallized here with perchlorate counter-ions as a di­chloro­methane tris­olvate, C44H28Br4N4 2+·2ClO4 −·3CH2Cl2. The centrosymmetric neutral species is observed to have a mild ‘ruffling’ of the pyrrole rings and is essentially planar throughout; intra­molecular N—H⋯N hydrogen bonds occur. In contrast, the dication exhibits considerable deformation, with the pyrrole rings oriented well out of the plane of the porphyrin, resulting in a ‘saddle’ conformation of the ring. The charged species forms N—H⋯O hydrogen bonds to the perchlorate anions, which lie above and below the plane of the porphyrin ring. Distortions to the planarity of the pyrrole rings in both cases are very minor. The characterization of the neutral species represents a low-temperature redetermination of the previous room-temperature analyses [Zou et al. (1995 ▸). Acta Cryst. C51, 760–761; Rayati et al. (2008 ▸). Polyhedron, pp. 2285–2290], which showed disorder and physically unrealistic displacement parameters. PMID:27308051

  9. Sensitive voltammetric sensor based on isopropanol-Nafion-PSS-GR nanocomposite modified glassy carbon electrode for determination of clenbuterol in pork.

    PubMed

    Wang, Ling; Yang, Ran; Chen, Jing; Li, Jianjun; Qu, Lingbo; de B Harrington, Peter

    2014-12-01

    In the present study, poly(sodium 4-styrenesulfonate) (PSS) functionalized graphene (GR) was synthesised via a simple one-step chemical reduction of exfoliated graphite oxides in the presence of PSS. Characterisation of as-made nanocomposite using Fourier transform infrared spectroscopy (FT-IR) and ultraviolet and visible spectroscopy (UV-vis) clearly demonstrate the successful attachment of PSS to graphene sheets. A novel clenbuterol (CLB) electrochemical sensor was fabricated based on isopropanol-Nafion-PSS-GR composite film modified glassy carbon electrode. In the Britton-Robinson buffer (pH 1.2), the sensor exhibited superior electrocatalytic activity towards the oxidation of CLB. Applying linear sweep voltammetry, a good linear relationship of the oxidation peak current with respect to concentrations of CLB cross the range of 7.5 × 10(-8)-2.5 × 10(-5)mol L(-1) and a detection limit of 2.2 × 10(-8) mol L(-1) were achieved. The proposed method was successfully applied for the determination of CLB in pork.

  10. Low temperature growth, freezing survival, and production of antifreeze protein by the plant growth promoting rhizobacterium Pseudomonas putida GR12-2.

    PubMed

    Sun, X; Griffith, M; Pasternak, J J; Glick, B R

    1995-09-01

    The plant growth promoting rhizobacterium Pseudomonas putida GR12-2 was originally isolated from the rhizosphere of plants growing in the Canadian High Arctic. Here we report that this bacterium was able to grow and promote root elongation of both spring and winter canola at 5 degrees C, a temperature at which only a relatively small number of bacteria are able to proliferate and function. In addition, the bacterium survived exposure to freezing temperatures, i.e., -20 and -50 degrees C. In an effort to determine the mechanistic basis for this behaviour, it was discovered that following growth at 5 degrees C, P. putida GR12-2 synthesized and secreted to the growth medium a protein with antifreeze activity. Analysis of the spent growth medium, following concentration by ultrafiltration, by SDS-polyacrylamide gel electrophoresis revealed the presence of one major protein with a molecular mass of approximately 32-34 kDa and a number of minor proteins. However, at this point it is not known which of these proteins contains the antifreeze activity. PMID:7585354

  11. Ginsenoside Rg1 promotes osteogenic differentiation of rBMSCs and healing of rat tibial fractures through regulation of GR-dependent BMP-2/SMAD signaling

    PubMed Central

    Gu, Yanqing; Zhou, Jinchun; Wang, Qin; Fan, Weimin; Yin, Guoyong

    2016-01-01

    Fracture healing is closely related to the number and activity of bone marrow mesenchymal stem cells (BMSCs) near the fracture site. The present study was to investigate the effect of Rg1 on osteogenic differentiation of cultured BMSCs and related mechanisms and on the fracture healing in a fracture model. In vitro experiments showed that Rg1 promoted the proliferation and osteogenic differentiation of BMSCs. Western blot analyses demonstrated that Rg1 promoted osteogenic differentiation of BMSCs through the glucocorticoid receptor (GR)-dependent BMP-2/Smad signaling pathway. In vivo, X-ray examination showed that callus growth in rats treated with Rg1 was substantially faster than that in control rats after fracture. The results of H&E and Safranin-O/Fast Green staining revealed that, compared with controls, rats in the Rg1 treatment group had a significantly higher proportion of trabecular bone but a much lower proportion of fibers and cartilage components inside the callus. Micro-CT suggested that bone mineral density (BMD), percent bone volume (BV/TV), trabecular number (Tb.N), and trabecular thickness (Tb.Th) were significantly increased in the treatment group, whereas trabecular separation (Tb.Sp) was significantly reduced. Thus, Rg1 promotes osteogenic differentiation by activating the GR/BMP-2 signaling pathway, enhances bone calcification, and ultimately accelerates the fracture healing in rats. PMID:27141994

  12. Granulocyte colony-stimulating factor promotes tumor angiogenesis via increasing circulating endothelial progenitor cells and Gr1+CD11b+ cells in cancer animal models.

    PubMed

    Okazaki, Tatsuma; Ebihara, Satoru; Asada, Masanori; Kanda, Akio; Sasaki, Hidetada; Yamaya, Mutsuo

    2006-01-01

    Recombinant granulocyte colony-stimulating factor (G-CSF) is used for cancer patients with myelosuppression induced by chemotherapy. G-CSF has been reported to progress tumor growth and angiogenesis, but the precise mechanism of tumor angiogenesis activated by G-CSF has not been fully clarified. N-terminal-mutated recombinant human G-CSF administration increased WBCs and neutrophils in peripheral blood and reduced bone marrow stromal cell-derived factor-1 in mice, indicating its biological relevance. Mice were inoculated with Lewis lung carcinoma cells (LLCs) or KLN205 cells and treated with G-CSF. G-CSF accelerated tumor growth and intratumoral vessel density, while it did not accelerate proliferation of LLCs, KLN205 cells or human umbilical vein endothelial cells in vitro. In the absence of tumors, G-CSF did not increase circulating cells that displayed phenotypic characteristics of endothelial progenitor cells (EPCs). In the presence of tumors, G-CSF increased circulating EPCs. In addition, G-CSF treatment increased immune suppressor and endothelial cell-differentiating Gr1+CD11b+ cells in tumor-bearing mice. We conclude that G-CSF promotes tumor growth by activating tumor angiogenesis via increasing circulating EPCs and Gr1+CD11b+ cells in cancer animal models.

  13. An analysis of the origin of an early medieval group of individuals from Gródek based on the analysis of stable oxygen isotopes.

    PubMed

    Lisowska-Gaczorek, A; Kozieł, S; Cienkosz-Stepańczak, B; Mądrzyk, K; Pawlyta, J; Gronkiewicz, S; Wołoszyn, M; Szostek, K

    2016-08-01

    In the early Middle Ages, the region of the Cherven Towns, which is now located on both sides of the Polish-Ukrainian border, was fiercely contested by Slavs in the process of forming their early states. The main objective of the present study was to investigate the homogeneity of an early medieval population uncovered in that region, in the town of Gródek on the Bug River, by screening for non-local individuals. The origin of the studied skeletons was ascertained using analysis of oxygen isotopes in the phosphates isolated from bone tissue. In this paper, the isotope ratios obtained for samples collected from 62 human skeletons were compared to the background δ(18)O (in precipitation water) from the regions of Kraków (south-eastern Poland), Lviv (western Ukraine), Brest (western Belarus), and Gródek, as well as to the ratios determined for the animals coexisting with the studied population. Proportions of oxygen isotopes obtained for all the studied individuals were found to be similar to those for the precipitation water and animals, which indicates the absence of bone fragments of individuals originating in other regions. PMID:27255160

  14. An analysis of the origin of an early medieval group of individuals from Gródek based on the analysis of stable oxygen isotopes.

    PubMed

    Lisowska-Gaczorek, A; Kozieł, S; Cienkosz-Stepańczak, B; Mądrzyk, K; Pawlyta, J; Gronkiewicz, S; Wołoszyn, M; Szostek, K

    2016-08-01

    In the early Middle Ages, the region of the Cherven Towns, which is now located on both sides of the Polish-Ukrainian border, was fiercely contested by Slavs in the process of forming their early states. The main objective of the present study was to investigate the homogeneity of an early medieval population uncovered in that region, in the town of Gródek on the Bug River, by screening for non-local individuals. The origin of the studied skeletons was ascertained using analysis of oxygen isotopes in the phosphates isolated from bone tissue. In this paper, the isotope ratios obtained for samples collected from 62 human skeletons were compared to the background δ(18)O (in precipitation water) from the regions of Kraków (south-eastern Poland), Lviv (western Ukraine), Brest (western Belarus), and Gródek, as well as to the ratios determined for the animals coexisting with the studied population. Proportions of oxygen isotopes obtained for all the studied individuals were found to be similar to those for the precipitation water and animals, which indicates the absence of bone fragments of individuals originating in other regions.

  15. Energy response of GR-200A thermoluminescence dosemeters to 60Co and to monoenergetic synchrotron radiation in the energy range 28-40 keV.

    PubMed

    Emiro, F; Di Lillo, F; Mettivier, G; Fedon, C; Longo, R; Tromba, G; Russo, P

    2016-01-01

    The response of LiF:Mg,Cu,P thermoluminescence dosemeters (type GR-200A) to monoenergetic radiation of energy 28, 35, 38 and 40 keV was evaluated with respect to irradiation with a calibrated (60)Co gamma-ray source. High-precision measurements of the relative air kerma response performed at the SYRMEP beamline of the ELETTRA synchrotron radiation facility (Trieste, Italy) showed a significant deviation of the average response to low-energy X-rays from that to (60)Co, with an over-response from 6 % (at 28 keV) to 22 % (at 40 keV). These data are not consistent with literature data for these dosemeters, where model predictions gave deviation from unity of the relative air kerma response of about 10 %. The authors conclude for the need of additional determinations of the low-energy relative response of GR-200A dosemeters, covering a wider range of monoenergetic energies sampled at a fine energy step, as planned in future experiments by their group at the ELETTRA facility.

  16. Investigation of Seasonal Cycles of CO, CH4, N2O, and O3 in the High Arctic at Eureka, Canada and Barrow, Alaska using Infrared Emission Spectroscopy

    NASA Astrophysics Data System (ADS)

    Tran, S.; Mariani, Z.; Conway, S. A.; Lutsch, E.; Rowe, P. M.; Kasai, Y.; Strong, K.

    2015-12-01

    The High Arctic experiences prolonged periods of total darkness in the winter and continuous daylight in the summer, influencing the atmosphere and its composition in ways that are still not fully understood. Making atmospheric measurements in this remote region is challenging, particularly during polar night when solar-viewing instruments are not operational. By using infrared emission spectroscopy, which is independent of sunlight, we are able to document year-round the total column abundances of carbon monoxide (CO), methane (CH4), nitrous oxide (N2O), and ozone (O3). Measurements made at two Arctic sites are presented in this study: the Polar Environment Atmospheric Research Laboratory (PEARL, Eureka, Nunavut, Canada, 80.05°N, 86.42°W) and the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) facility on the North Slope of Alaska (NSA, Barrow, Alaska, 71.19°N, 156.36°W). At both sites, Extended-range Atmospheric Emitted Radiance Interferometers (E-AERIs), are used to measure the absolute downwelling infrared emission from the atmosphere between 400 and 3000 cm-1. The E-AERI has a moderate resolution of 1 cm-1 and provides information about trace gases columns with high sensitivity to the lower troposphere. At PEARL, the instrument was installed in October 2008. In addition, a similar instrument, the University of Idaho's Polar AERI (P-AERI) was installed at PEARL from March 2006 to June 2009. At NSA, the E-AERI has been operating since February 1998. Total columns of CO, CH4, N2O and O3 have been retrieved from 2006 to 2015 at PEARL and from 1998 to 2014 at NSA using the SFIT4 algorithm. These two datasets will be compared along with measurements made by high-resolution solar-viewing infrared spectrometers located at PEARL and at Poker Flat, Alaska (65.12°N, 147.47°W) to validate our results. These measurements will be used to present the annual, seasonal and diurnal variabilities of trace gases in the high Arctic at two different

  17. Relativistic effects on nuclear magnetic shieldings of CHnX4-n and CHXYZ (X, Y, Z = H, F, Cl, Br, I)

    NASA Astrophysics Data System (ADS)

    Melo, Juan I.; Maldonado, Alejandro F.; Aucar, Gustavo A.

    2012-12-01

    Nuclear magnetic shieldings of both carbon and hydrogen atoms of haluro methyl molecules are highly influenced by the substitution of one or more hydrogen by halogen heavy atoms. We applied the linear response elimination of small components, LRESC, formalism to calculate such shieldings and learn whether including only few terms is enough for getting quantitative reproduction of the total shieldings or not. First, we discuss the contribution of all leading relativistic corrections to σ(C), in CHX2I molecular models with X = H, F, and Cl, and show that spin-orbit (SO) effects are the main ones. After adding the SO effects to the non-relativistic (NR) results, we obtain ˜ 97% (93%) of the total LRESC values for σ(C) (σ(H)). The magnitude of SO terms increases when the halogen atom becomes heavier. In this case, such contributions to σ(C) can be extrapolated as a function of Z, the halogen atomic number. Furthermore, when paramagnetic spin-orbit (PSO) contributions are also considered, we obtain results that are within 1% of the total LRESC value. Then we study in detail the main electronic mechanisms involved to contribute C and H shieldings on CHnX4 - n (n = 1, 3), and CHXYZ (X, Y, Z = F, Cl, Br, I) model compounds. The pattern of σ(C) for all series of compounds follows a normal halogen dependence (NHD), though with different rate of increase. A special family of compounds is that of CHF2X for which σnr(C) follows an inverse halogen dependence though the total shielding have a NHD due to the SO contributions. For the series CH3X (X = F, Cl, Br and I), we found that σSO ˜ Z_X^{2.53}. Another important finding of this work is the logarithmic dependence of σSO(C) with the substituent atomic number: ln σSO(C) = A_X + a_X Z_Y for both family of compounds CH2XY and CHX2Y. We also performed four-component calculations using the spin-free Hamiltonian to obtain SO contributions within a four-component framework.

  18. Drivers of small scale variability in soil-atmosphere fluxes of CH4, N2O and CO2 in a forest soil

    NASA Astrophysics Data System (ADS)

    Maier, Martin; Nicolai, Clara; Wheeler, Denis; Lang, Friedeike; Paulus, Sinikka

    2016-04-01

    Soil-atmosphere fluxes of CH4, N2O and CO2 can vary on different spatial scales, on large scales between ecosystems but also within apparently homogenous sites. While CO2 and CH4 consumption is rather evenly distibuted in well aerated soils, the production of N2O and CH4 seems to occur at hot spots that can be associated with anoxic or suboxic conditions. Small-scale variability in soil properties is well-known from field soil assesment, affecting also soil aeration and thus theoretically, greenhouse gas fluxes. In many cases different plant species are associated with different soil conditions and vegetation mapping should therefor combined with soil mapping. Our research objective was explaining the small scale variability of greenhouse gas fluxes in an apparently homogeneous 50 years old Scots Pine stand in a former riparian flood plain.We combined greenhouse gas measurements and soil physical lab measurments with field soil assessment and vegetation mapping. Measurements were conducted with at 60 points at a plot of 30 X 30 m at the Hartheim monitoring site (SW Germany). For greenhouse gas measurements a non-steady state chamber system and laser analyser, and a photoacoustic analyser were used. Our study shows that the well aerated site was a substantial sink for atmospheric CH4 (-2.4 nmol/m² s) and also a for N2O (-0.4 nmol/m² s), but less pronounced, whereas CO2 production was a magnitude larger (2.6 μmol/m² s). The spatial variability of the CH4 consumption of the soils could be explained by the variability of the soil gas diffusivity (measured in situ + using soil cores). Deviations of this clear trend were only observed at points where decomposing woody debris was directly under the litter layer. Soil texture ranged from gravel, coarse sand, fine sand to pure silt, with coarser texture having higher soil gas diffusivity. Changes in texture were rather abrupt at some positions or gradual at other positions, and were well reflected in the vegetation

  19. Relativistic effects on nuclear magnetic shieldings of CH(n)X(4-n) and CHXYZ (X, Y, Z = H, F, Cl, Br, I).

    PubMed

    Melo, Juan I; Maldonado, Alejandro F; Aucar, Gustavo A

    2012-12-01

    Nuclear magnetic shieldings of both carbon and hydrogen atoms of haluro methyl molecules are highly influenced by the substitution of one or more hydrogen by halogen heavy atoms. We applied the linear response elimination of small components, LRESC, formalism to calculate such shieldings and learn whether including only few terms is enough for getting quantitative reproduction of the total shieldings or not. First, we discuss the contribution of all leading relativistic corrections to σ(C), in CHX(2)I molecular models with X = H, F, and Cl, and show that spin-orbit (SO) effects are the main ones. After adding the SO effects to the non-relativistic (NR) results, we obtain ~ 97% (93%) of the total LRESC values for σ(C) (σ(H)). The magnitude of SO terms increases when the halogen atom becomes heavier. In this case, such contributions to σ(C) can be extrapolated as a function of Z, the halogen atomic number. Furthermore, when paramagnetic spin-orbit (PSO) contributions are also considered, we obtain results that are within 1% of the total LRESC value. Then we study in detail the main electronic mechanisms involved to contribute C and H shieldings on CH(n)X(4 - n) (n = 1, 3), and CHXYZ (X, Y, Z = F, Cl, Br, I) model compounds. The pattern of σ(C) for all series of compounds follows a normal halogen dependence (NHD), though with different rate of increase. A special family of compounds is that of CHF(2)X for which σ(nr)(C) follows an inverse halogen dependence though the total shielding have a NHD due to the SO contributions. For the series CH(3)X (X = F, Cl, Br and I), we found that σ(SO) ~ Z(X) (2.53). Another important finding of this work is the logarithmic dependence of σ(SO)(C) with the substituent atomic number: ln σ(SO)(C) = A(X) + a(X) Z(Y) for both family of compounds CH(2)XY and CHX(2)Y. We also performed four-component calculations using the spin-free Hamiltonian to obtain SO contributions within a four-component framework.

  20. Cellular and humoral mediated immunity and distribution of viral antigen in chickens after infection with a low pathogenic avian influenza virus (H4N6) isolated from wild ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four-week-old commercial chickens were intranasally inoculated with an H4N6 low pathogenicity avian influenza virus (LPAIV) isolated from a duck in Ukraine. Cecum, spleen, lung, and trachea samples were collected from birds from 1 to 21 days post inoculation (dpi) and examined by immunohistochemica...

  1. Fabrication of MgAl{sub 2}O{sub 4} tunnel barrier by radio frequency-sputtering method and magnetoresistance effect through it with Fe or Fe{sub 4}N ferromagnetic electrode

    SciTech Connect

    Tsunoda, Masakiyo; Chiba, Ryoichi; Kabara, Kazuki

    2015-05-07

    Spinel MgAl{sub 2}O{sub 4} thin films were deposited on MgO single-crystal substrates and epitaxial Fe (or Fe{sub 4}N) thin films by RF-sputtering from a ceramic target. Epitaxial relationship was confirmed by X-ray diffraction analysis between the crystalline spinel MgAl{sub 2}O{sub 4} films and the respective substrate and underlayers, while no diffraction peak was observed from the films deposited on amorphous substrates. Spin-valve type magnetic tunnel junctions (MTJs) with a stacking structure of Fe [Fe{sub 4}N]/MgAl{sub 2}O{sub 4}/CoFeB/Ru/Fe/MnIr exhibited normal [inverse] tunnel magnetoresistance (TMR) effect, reflecting the sign of spin polarization of Fe [Fe{sub 4}N]. The maximum magnitude of the TMR ratio obtained for the Fe-based and Fe{sub 4}N-based MTJs was 67% and 18%, respectively. The resistance area product values of the MTJs were significantly larger than the reported values for the MTJs with a post-oxidized spinel MgAl{sub 2}O{sub 4} barrier.

  2. Fabrication of MgAl2O4 tunnel barrier by radio frequency-sputtering method and magnetoresistance effect through it with Fe or Fe4N ferromagnetic electrode

    NASA Astrophysics Data System (ADS)

    Tsunoda, Masakiyo; Chiba, Ryoichi; Kabara, Kazuki

    2015-05-01

    Spinel MgAl2O4 thin films were deposited on MgO single-crystal substrates and epitaxial Fe (or Fe4N) thin films by RF-sputtering from a ceramic target. Epitaxial relationship was confirmed by X-ray diffraction analysis between the crystalline spinel MgAl2O4 films and the respective substrate and underlayers, while no diffraction peak was observed from the films deposited on amorphous substrates. Spin-valve type magnetic tunnel junctions (MTJs) with a stacking structure of Fe [Fe4N]/MgAl2O4/CoFeB/Ru/Fe/MnIr exhibited normal [inverse] tunnel magnetoresistance (TMR) effect, reflecting the sign of spin polarization of Fe [Fe4N]. The maximum magnitude of the TMR ratio obtained for the Fe-based and Fe4N-based MTJs was 67% and 18%, respectively. The resistance area product values of the MTJs were significantly larger than the reported values for the MTJs with a post-oxidized spinel MgAl2O4 barrier.

  3. A novel yellow-emitting SrAlSi{sub 4}N{sub 7}:Ce{sup 3+} phosphor for solid state lighting: Synthesis, electronic structure and photoluminescence properties

    SciTech Connect

    Ruan, Jian; Xie, Rong-Jun; Funahashi, Shiro; Tanaka, Yoshinori; Takeda, Takashi; Suehiro, Takayuki; Hirosaki, Naoto; Li, Yuan-Qiang

    2013-12-15

    Ce{sup 3+}-doped and Ce{sup 3+}/Li{sup +}-codoped SrAlSi{sub 4}N{sub 7} phosphors were synthesized by gas pressure sintering of powder mixtures of Sr{sub 3}N{sub 2}, AlN, α-Si{sub 3}N{sub 4}, CeN and Li{sub 3}N. The phase purity, electronic crystal structure, photoluminescence properties of SrAlSi{sub 4}N{sub 7}:Ce{sup 3+}(Ce{sup 3+}/Li{sup +}) were investigated in this work. The band structure calculated by the DMol{sup 3} code shows that SrAlSi{sub 4}N{sub 7} has a direct band gap of 3.87 eV. The single crystal analysis of Ce{sup 3+}-doped SrAlSi{sub 4}N{sub 7} indicates a disordered Si/Al distribution and nitrogen vacnacy defects. SrAlSi{sub 4}N{sub 7} was identified as a major phase of the fired powders, and Sr{sub 5}Al{sub 5}Si{sub 21}N{sub 35}O{sub 2} and AlN as minor phases. Both Ce{sup 3+} and Ce{sup 3+}/Li{sup +} doped SrAlSi{sub 4}N{sub 7} phosphors can be efficiently excited by near-UV or blue light and show a broadband yellow emission peaking around 565 nm. A highest external quantum efficiency of 38.3% under the 450 nm excitation was observed for the Ce{sup 3+}/Li{sup +}-doped SrAlSi{sub 4}N{sub 7} (5 mol%). A white light LED lamp with color temperature of 6300 K and color rendering index of Ra=78 was achieved by combining Sr{sub 0.97}Al{sub 1.03}Si{sub 3.997}N/94/maccounttest14=t0005{sub 1}8193 {sub 7}:Ce{sup 3+}{sub 0.03} with a commercial blue InGaN chip. It indicates that SrAlSi{sub 4}N{sub 7}:Ce{sup 3+} is a promising yellow emitting down-conversion phosphor for white LEDs. - Graphical abstract: One-phosphor converted white light-emitting diode (LED) was fabricated by combining a blue LED chip and a yellow-emitting SrAlSi4N7:Ce{sup 3+} phosphor (see inset), which has the color rendering index of 78 and color temperature of 6300 K. - Highlights: • We reported a new yellow nitride phosphor suitable for solid state lighting. • We solved the crystal structure and evidenced a disordered Si/Al distribution. • We fabricated a high color rendering

  4. Radiative effects of CH4, N2O, halocarbons and the foreign-broadened H2O continuum: A GCM experiment

    NASA Astrophysics Data System (ADS)

    Schwarzkopf, M. Daniel; Ramaswamy, V.

    1999-04-01

    The simplified exchange approximation (SEA) method for calculation of infrared radiative transfer, used for general circulation model (GCM) climate simulations at the Geophysical Fluid Dynamics Laboratory (GFDL) and other institutions, has been updated to permit inclusion of the effects of methane (CH4), nitrous oxide (N2O), halocarbons, and water-vapor-air molecular broadening (foreign broadening). The effects of CH4 and N2O are incorporated by interpolation of line-by-line (LBL) transmissivity calculations evaluated at standard species concentrations; halocarbon effects are calculated from transmissivities computed using recently measured frequency-dependent absorption coefficients. The effects of foreign broadening are included by adoption of the "CKD" formalism for the water vapor continuum [Clough et al., 1989]. For a standard midlatitude summer profile, the change in the net infrared flux at the model tropopause due to the inclusion of present-day concentrations of CH4 and N2O is evaluated to within ˜5% of corresponding LBL results; the change in net flux at the tropopause upon inclusion of 1 ppbv of CFC-11, CFC-12, CFC-113, and HCFC-22 is within ˜10% of the LBL results. Tropospheric heating rate changes resulting from the introduction of trace species (CH4, N2O, and halocarbons) are calculated to within ˜0.03 K/d of the LBL results. Introduction of the CKD water vapor continuum causes LBL-computed heating rates to decrease by up to ˜0.4 K/d in the upper troposphere and to increase by up to ˜0.25 K/d in the midtroposphere; the SEA method gives changes within ˜0.05 K/d of the LBL values. The revised SEA formulation has been incorporated into the GFDL "SKYHI" GCM. Two simulations (using fixed sea surface temperatures and prescribed clouds) have been performed to determine the changes to the model climate from that of a control calculation upon inclusion of (1) the trace species and (2) the foreign-broadened water vapor continuum. When the trace species

  5. Performance analysis of the GR712RC dual-core LEON3FT SPARC V8 processor in an asymmetric multi-processing environment

    NASA Astrophysics Data System (ADS)

    Giusi, Giovanni; Liu, Scige J.; Galli, Emanuele; Di Giorgio, Anna M.; Farina, Maria; Vertolli, Nello; Di Lellis, Andrea M.

    2016-07-01

    In this paper we present the results of a series of performance tests carried out on a prototype board mounting the Cobham Gaisler GR712RC Dual Core LEON3FT processor. The aim was the characterization of the performances of the dual core processor when used for executing a highly demanding lossless compression task, acting on data segments continuously copied from the static memory to the processor RAM. The selection of the compression activity to evaluate the performances was driven by the possibility of a comparison with previously executed tests on the Cobham/Aeroflex Gaisler UT699 LEON3FT SPARC™ V8. The results of the test activity have shown a factor 1.6 of improvement with respect to the previous tests, which can easily be improved by adopting a faster onboard board clock, and provided indications on the best size of the data chunks to be used in the compression activity.

  6. Imerslund-Gräsbeck syndrome in a 25-month-old Italian girl caused by a homozygous mutation in AMN.

    PubMed

    De Filippo, Gianpaolo; Rendina, Domenico; Rocco, Vincenzo; Esposito, Teresa; Gianfrancesco, Fernando; Strazzullo, Pasquale

    2013-01-01

    Imerslund-Gräsbeck syndrome is a rare autosomal recessive disorder, characterized by vitamin B12 deficiency due to selective malabsorption of the vitamin and usually results in megaloblastic anemia appearing in childhood. It is responsive to parenteral vitamin B12 therapy.The estimated prevalence (calculated based on Scandinavian data) is less than 6:1,000,000. However, many cases may be misdiagnosed.When there is reasonable evidence to suspect that a patient suffers from IGS, a new and straightforward approach to diagnosis is mutational analysis of the appropriate genes. We report for the first time the case of a girl of Italian ancestry with IGS genetically confirmed by the detection of a homozygous missense mutation in the AMN gene (c.208-2 A > G). PMID:24044590

  7. Scaling Theory of the Mott Transition and Breakdown of the Gr"uneisen Scaling Near a Finite-Temperature Critical End Point

    NASA Astrophysics Data System (ADS)

    Bartosch, Lorenz

    2012-02-01

    We discuss a scaling theory of the lattice response in the vicinity of a finite-temperature critical end point. The thermal expansivity is shown to be more singular than the specific heat such that the Gr"uneisen ratio diverges as the critical point is approached, except for its immediate vicinity. More generally, we express the thermal expansivity in terms of a scaling function which we explicitly evaluate for the two-dimensional Ising universality class. Recent thermal expansivity measurements on the layered organic conductor κ-(BEDT-TTF)2X close to the Mott transition are well described by our theory.[2mm] [1] Lorenz Bartosch, Mariano de Souza, and Michael Lang, Physical Review Letters 104, 245701 (2010).

  8. Invagination intestinale aiguë consécutive à un lipome grèlique: à propos d'un cas et revue de la littérature

    PubMed Central

    Bentama, Kamal; Chemlal, Iliass; Benabbou, Mohamed; El Abssi, Mohamed; El Ouananni, Meouhamed; Cherrab, Mouhamed; Faricha, Alami; Errougani, Abdelkader; Amraoui, Mohamed; Chekoff, Rachid

    2012-01-01

    L'invagination intestinale aiguë est une pathologie du nourrisson et du petit enfant. Sa survenue chez l'adulte est très inhabituelle. Elle est d’étiologie diverse. Dans l'immense majorité des cas, elle est secondaire à une tumeur qui peut être bénigne ou maligne. L'invagination intestinale sur lipome est exceptionnelle. Nous rapportons un cas d'invagination intestinale grêlo-grêlique sur lipome. PMID:23133698

  9. Feasibility and benefits of group-based exercise in residential aged care adults: a pilot study for the GrACE programme

    PubMed Central

    Henwood, Timothy; Climstein, Mike; Keogh, Justin William Leslie

    2016-01-01

    The objective of the study was to examine the feasibility and benefits of a group resistance training exercise programme for improving muscle function in institutionalised older adults. A feasibility and acceptability study was designed for a residential aged care (RAC) facility, based on the Gold Coast, Australia. Thirty-seven adults, mean age 86.8 ± 6.1 years (30 females) living in a RAC facility. Participants were allocated into an exercise (n = 20) or control (n = 17) group. The exercise group, the Group Aged Care Exercise (GrACE) programme, performed 12 weeks of twice weekly resistance exercises. Feasibility was measured via recruitment rate, measurement (physiological and surveys) completion rate, loss-to-follow-up, exercise session adherence, adverse events, and ratings of burden and acceptability. Muscle function was assessed using gait speed, sit-to-stand and handgrip strength assessments. All intervention participants completed pre- and post-assessments, and the exercise intervention, with 85% (n = 17) of the group attending ≥ 18 of the 24 sessions and 15% (n = 3) attending all sessions. Acceptability was 100% with exercise participants, and staff who had been involved with the programme strongly agreed that the participants “Benefited from the programme.” There were no adverse events reported by any participants during the exercise sessions. When compared to the control group, the exercise group experienced significant improvements in gait speed (F(4.078) = 8.265, p = 0.007), sit to stand performance (F(3.24) = 11.033, p = 0.002) and handgrip strength (F(3.697) = 26.359, p < 0.001). Resistance training via the GrACE programme is feasible, safe and significantly improves gait speed, sit-to-stand performance and handgrip strength in RAC adults. PMID:27231652

  10. Feasibility and benefits of group-based exercise in residential aged care adults: a pilot study for the GrACE programme.

    PubMed

    Fien, Samantha; Henwood, Timothy; Climstein, Mike; Keogh, Justin William Leslie

    2016-01-01

    The objective of the study was to examine the feasibility and benefits of a group resistance training exercise programme for improving muscle function in institutionalised older adults. A feasibility and acceptability study was designed for a residential aged care (RAC) facility, based on the Gold Coast, Australia. Thirty-seven adults, mean age 86.8 ± 6.1 years (30 females) living in a RAC facility. Participants were allocated into an exercise (n = 20) or control (n = 17) group. The exercise group, the Group Aged Care Exercise (GrACE) programme, performed 12 weeks of twice weekly resistance exercises. Feasibility was measured via recruitment rate, measurement (physiological and surveys) completion rate, loss-to-follow-up, exercise session adherence, adverse events, and ratings of burden and acceptability. Muscle function was assessed using gait speed, sit-to-stand and handgrip strength assessments. All intervention participants completed pre- and post-assessments, and the exercise intervention, with 85% (n = 17) of the group attending ≥ 18 of the 24 sessions and 15% (n = 3) attending all sessions. Acceptability was 100% with exercise participants, and staff who had been involved with the programme strongly agreed that the participants "Benefited from the programme." There were no adverse events reported by any participants during the exercise sessions. When compared to the control group, the exercise group experienced significant improvements in gait speed (F(4.078) = 8.265, p = 0.007), sit to stand performance (F(3.24) = 11.033, p = 0.002) and handgrip strength (F(3.697) = 26.359, p < 0.001). Resistance training via the GrACE programme is feasible, safe and significantly improves gait speed, sit-to-stand performance and handgrip strength in RAC adults. PMID:27231652

  11. Properties of ash-infused hail during the Grímsvötn 2011 eruption and implications for radar detection of volcanic columns

    NASA Astrophysics Data System (ADS)

    Arason, Þórður; Þorláksdóttir, Svava B.; Sigurðsson, Geirfinnur S.; Yeo, Richard F.; Thorsteinsson, Thorsteinn

    2013-04-01

    The latest Grímsvötn volcanic eruption in Iceland lasted for a week, 21-28 May 2011, while most of the tephra was erupted in the first 24 hours. During the early hours the volcanic column rose to about 20-25 km altitude. The Grímsvötn caldera is within the Vatnajökull glacier and most of the tephra was deposited on the glacier. Fortunately, for our study of ash-infused hail deposited from the column, the surface air temperatures on the glacier were below freezing level during the first few weeks after the eruption. In early June 2011 the ash deposits around the eruption site were studied, with special focus on thick distinct intermittent layers of ash-infused hail. Close-up photographs of the in-situ hail layers were taken and hail samples collected, some were kept frozen while others were allowed to melt. Most of the hail had grain sizes between 1 and 2 mm with various visual grades of ash density, from almost clear hail to ice-glaced spherical balls of packed fine ash. Both the ash and hail grain size distributions of the samples were analyzed as well as their water content. The much larger grain size of the hail than of the ash has important implications for some effective physical properties and remote detection of ash in volcanic columns. These changes in effective grain size lead to increased precipitation of ash, and affect radar reflectivity. The influence of hail formation in volcanic columns on mass flux estimates based on radar measurements will be discussed.

  12. MODIS-derived albedo changes of Vatnajökull (Iceland) due to tephra deposition from the 2004 Grímsvötn eruption

    NASA Astrophysics Data System (ADS)

    Möller, Rebecca; Möller, Marco; Björnsson, Helgi; Guðmundsson, Sverrir; Pálsson, Finnur; Oddsson, Björn; Kukla, Peter A.; Schneider, Christoph

    2014-02-01

    Occasionally, the surface albedo of glaciers may be abruptly altered by deposition of light-absorbing aerosols, which consequently has a sustained impact on their energy- and mass balance. Volcanic eruptions may spread tephra deposits over regional-scale glacierized areas. In November 2004, an explosive, phreatomagmatic eruption of the subglacial Grímsvötn volcano, located in the centre of the Icelandic ice cap Vatnajökull, produced ash fall covering an area of ∼1280 km2 in the northwestern part of the ice cap. This event affected the surface albedo of the glacier over several years after the eruption. We use MODIS surface-albedo data and an ash-dispersal dataset obtained from in situ measurements on the ice cap to develop a novel, empirically based modelling approach to describe the albedo decrease across the glacier surface caused by the deposited tephra. We present analyses of the temporal and spatial variability of the albedo pattern over the post-eruption period from November 2004 to December 2008. The tephra-induced albedo changes were largest and most widely distributed over the glacier surface during the summer season 2005. The observed albedo decrease reached 0.35 when compared to modelled, undisturbed conditions. In the low-lying ablation area, where strong surface melting takes place, the tephra influence on albedo diminished with time and completely faded out within four years after the eruption. In contrast, at the rim of the Grímsvötn caldera surrounding the eruption site the tephra influences on albedo considerably increased with time. Throughout the rest of the high-lying accumulation area, the influences were scattered in both space and time.

  13. Impact of Ashfalls from Eyjafjallajökull and Grímsvötn Volcanoes on Glacier Ablation on Iceland - a Field Experiment

    NASA Astrophysics Data System (ADS)

    Möller, R.; Möller, M.; Kukla, P. A.; Schneider, C.

    2015-12-01

    The albedo of glaciers may be altered by deposition of light-absorbing aerosols, which consequently has an impact on their energy- and mass balance. Icelandic volcanoes have produced frequent eruptions within the recent past that spread tephra over extensive areas. The glaciers of Iceland are thus an ideal location for studies related to the influence of supraglacial tephra layers on ablation. The two latest subglacial eruptions that induced considerable amounts of ashfall over major Icelandic ice caps were the one of Eyjafjallajökull in April and May 2010 and the one of Grímsvötn in May 2011. The different chemical compositions of the ashes produced by those two eruptions are also noticeable in their distinct thermal properties. In summer 2015, a field experiment was conducted on western Vatnajökull ice cap. In this experiment, the influence of volcanic tephra from both eruptions on surface ablation is monitored by automated measurements. Artificial plots with varying types and thicknesses of tephra were installed on the glacier. Two types of pristine tephra were compared. One was sampled from inside the caldera of Eyjafjallajökull volcano and one from rocky outcrops at the southern caldera rim of Grímsvötn volcano. Tephra thickness across the different artificial plots ranged from 0.5 to 200 mm. The surface ablation on the plots was continuously monitored by automated measurements. For selected plots, additionally changes of the albedo and the temperature profile through the tephra layer were measured. An automatic weather station was set up for continuous meteorological monitoring. We here present first results from this field experiment. Analyses of the overall variability of surface ablation with tephra thickness are shown alongside with indications of dependencies on meteorological conditions, mainly solar radiation and rainfall. Special emphasis is placed on highlighting differences between the effects of the two different types of tephra.

  14. Irradiation embrittlement of reactor pressure vessel steel outside the astm specification A508 CL2

    NASA Astrophysics Data System (ADS)

    Pachur, D.; Krawczynski, S. J.; Derz, H.; Pott, G.

    1990-04-01

    Radiation embrittlement of reactor pressure vessel steels is of considerable significance for safety engineering. Steel manufacturers must therefore comply with specifications defined by national design codes. The extent to which a steel deviating from the specification is influenced by irradiation is being examined under the German Research Programme on the Integrity of Reactor Components. Charpy-V specimens were taken from a forged steel block longitudinally and vertically to the direction of main deformation and irradiated in the FRJ-1 research reactor at a temperature of 288 °C corresponding to the operating temperature of power reactors. The neutron fluences obtained ranged between 0.8 × 10 19 and 8 × 10 19n/ cm2. Instrumented pendulum impact tests have been evaluated and the load signals measured were analysed, fitting and calculating transition temperature curves and trend curves.

  15. Dielectric barrier discharge plasma treatment on E. coli: Influence of CH{sub 4}/N{sub 2}, O{sub 2}, N{sub 2}/O{sub 2}, N{sub 2}, and Ar gases

    SciTech Connect

    Majumdar, Abhijit; Hippler, Rainer; Singh, Rajesh Kumar; Palm, Gottfried J.

    2009-10-15

    Atmospheric pressure dielectric barrier discharge (DBD) plasma has been employed on Gram-negative bacteria, Escherichia coli BL21. Treatment was carried out using plasma generated with different compositions of gases: CH{sub 4}/N{sub 2} (1:2), O{sub 2}, N{sub 2}/O{sub 2} (1:1), N{sub 2}, and Ar, and by varying plasma power and treatment time. E. coli cells were exposed under the DBD plasma in triplicates, and their surviving numbers were observed in terms of colony forming units. It has been observed that the CH{sub 4}/N{sub 2} plasma exhibits relatively higher sterilization property toward E. coli compared to plasma generated by using O{sub 2}, N{sub 2}/O{sub 2}, N{sub 2}, and Ar gas mixtures. The time to kill up to 90% of the initial population of the E. coli cells was found to be about 2-3 min for CH{sub 4}/N{sub 2} and O{sub 2} gas mixture DBD plasma. A prolongation of treatment time and an increase in the dissipated power significantly improved the E. coli killing efficiency of the atmospheric pressure DBD plasma.

  16. Extension of the T{sub z} = {minus}3/2, A = 4n + 1 series of beta-delayed proton emitters to {sup 65}Se and {sup 73}Sr, and low energy beta-delayed proton emission from the T{sub z} = {minus}3/2, A = 4n + 3 nucleus {sup 23}Al

    SciTech Connect

    Batchelder, J.C.

    1993-12-01

    The series of known Tz = {minus}3/2, A = 4n + 1 nuclei has been extended to include the previously undiscovered isotopes {sup 65}Se and {sup 73}Sr, through the observation of beta-delayed proton emission via the isobaric analog state (IAS) of the beta-daughter (emitter). Due to the relatively large proton energies involved, these experiments were conducted using standard Si-Si {Delta}E-E telescopes. Beta-delayed protons arising from {sup 65}Se have been observed at an energy (laboratory) of 3.55 {plus_minus} 0.03 MeV, corresponding to the decay of the T = 3/2 isobaric analog state in {sup 65}As to the ground state of {sup 64}Ge. Similarly, beta-delayed protons from {sup 73}Sr at an energy of 3.75 {plus_minus} 0.04 MeV have been observed, corresponding to decay of the T = 3/2 isobaric analog state in {sup 73}Rb to the ground state of {sup 72}Kr. From the energies of these proton transitions, an improved prediction of the mass excesses of the two parent nuclei ({sup 65}Se and {sup 73}Sr) is made through the use of a Coulomb displacement formula. These predictions are {minus}33.41 {plus_minus} 0.26 and {minus}31.87 {plus_minus} 0.24 MeV for {sup 65}Se and {sup 73}Sr, respectively. Studies of low energy (down to {approximately}200 keV) beta-delayed protons from {sup 23}Al necessitated that a particle identification telescope with a low energy threshold for observation and identification of protons be developed. {sup 23}Al is of interest because of its role in the breakout of the hot CNO cycle leading to the astrophysical rp process.

  17. Crime detection of R. F. Navarro building using terrestrial/close-range photogrammetry as used in a Supreme Court case GR-102313

    NASA Astrophysics Data System (ADS)

    Navarro, Angel A.; Navarro, Marcela Z.

    1993-10-01

    Our space organization expertise has already been in full-blown space high-technological operations for pedagogical uses. Our space sciences are integrated into a cycle on terrestrial/close-range photogrammetry and remote sensing laboratory set-up. We have used terrestrial/close-range photogrammetry for crime detection on the R. F. Navarro Building as used for support in Supreme Court Case No. 102313 because of the principal need for accurate scale references. But if the photogrammetric work must be tied to an object coordinate system, this can usually be done later by rigid transformations to a few (even partially) known points on the object and as our organization is now specializing with the crime detection of a certain prewar R. F. Navarro Building with Cadastral Record Survey No. 189 (MNL-Manila, Philippines) using terrestrial/close-range photogrammetry to detect the criminal culprits in using preponderance-of-evidence for legal and scientific uses in Supreme Court Case G.R. No. 102313. So far, the results of our legal and scientific uses in Supreme Court case research are outlined and the outcome of this position paper.

  18. Dynamics, stratigraphy and proximal dispersal of supraglacial tephra during the ice-confined 2004 eruption at Grímsvötn Volcano, Iceland

    NASA Astrophysics Data System (ADS)

    Jude-Eton, T. C.; Thordarson, T.; Gudmundsson, M. T.; Oddsson, B.

    2012-07-01

    The basaltic, phreatomagmatic eruption of Grímsvötn volcano, Iceland, in November 2004 (G2004) lasted for 5 days, during which time two separate vents were active. Significant deposition of tephra occurred in the first 45 h only. We have subdivided the deposit into seven units (A-G) on the basis of differences in texture, grain size and componentry, and the presence of sharp contacts between the layers. The distribution of tephra lobes was used to infer the vent of origin for each unit. The G2004 deposit is poorly sorted overall and consists of non-vesicular to highly vesicular juvenile components. Units A and B comprise almost exclusively non- to poorly vesicular glass fragments, whereas units C-G contain at least 30 vol.% highly vesicular pumice. The proportion of non-juvenile fragments increases significantly in the final unit (unit F) of the main phase; non-juvenile fragments are restricted to the coarse (>0 Φ) fraction of the deposit. Main phase units C and E account for 80% of the total deposit volume, including the entire distal portion, and are interpreted to represent a mixture of (1) a widely dispersed component that fell from the upper margins of a strongly inclined (˜45°), 6-10 km high plume and (2) a locally dispersed (<3 km from source) component originating from pyroclastic density currents and minor tephra jets.

  19. Effect of Cutting Parameters on Thrust Force and Surface Roughness in Drilling of Al-2219/B4C/Gr Metal Matrix Composites

    NASA Astrophysics Data System (ADS)

    Ravindranath, V. M.; Basavarajappa, G. S. Shiva Shankar S.; Suresh, R.

    2016-09-01

    In aluminium matrix composites, reinforcement of hard ceramic particle present inside the matrix which causes tool wear, high cutting forces and poor surface finish during machining. This paper focuses on effect of cutting parameters on thrust force, surface roughness and burr height during drilling of MMCs. In the present work, discuss the influence of spindle speed and feed rate on drilling the pure base alloy (Al-2219), mono composite (Al- 2219+8% B4C) and hybrid composite (Al-2219+8%B4C+3%Gr). The composites were fabricated using liquid metallurgy route. The drilling experiments were conducted by CNC machine with TiN coated HSS tool, M42 (Cobalt grade) and carbide tools at various spindle speeds and feed rates. The thrust force, surface roughness and burr height of the drilled hole were investigated in mono composite and hybrid composite containing graphite particles, the experimental results show that the feed rate has more influence on thrust force and surface roughness. Lesser thrust force and discontinuous chips were produced during machining of hybrid composites when compared with mono and base alloy during drilling process. It is due to solid lubricant property of graphite which reduces the lesser thrust force, burr height and lower surface roughness. When machining with Carbide tool at low feed and high speeds good surface finish was obtained compared to other two types of cutting tool materials.

  20. Influence of xc functional on thermal-elastic properties of Ceria: A DFT-based Debye-Grüneisen model approach

    NASA Astrophysics Data System (ADS)

    Lee, Ji-Hwan; Tak, Youngjoo; Lee, Taehun; Soon, Aloysius

    Ceria (CeO2-x) is widely studied as a choice electrolyte material for intermediate-temperature (~ 800 K) solid oxide fuel cells. At this temperature, maintaining its chemical stability and thermal-mechanical integrity of this oxide are of utmost importance. To understand their thermal-elastic properties, we firstly test the influence of various approximations to the density-functional theory (DFT) xc functionals on specific thermal-elastic properties of both CeO2 and Ce2O3. Namely, we consider the local-density approximation (LDA), the generalized gradient approximation (GGA-PBE) with and without additional Hubbard U as applied to the 4 f electron of Ce, as well as the recently popularized hybrid functional due to Heyd-Scuseria-Ernzehof (HSE06). Next, we then couple this to a volume-dependent Debye-Grüneisen model to determine the thermodynamic quantities of ceria at arbitrary temperatures. We find an explicit description of the strong correlation (e.g. via the DFT + U and hybrid functional approach) is necessary to have a good agreement with experimental values, in contrast to the mean-field treatment in standard xc approximations (such as LDA or GGA-PBE). We acknowledge support from Samsung Research Funding Center of Samsung Electronics (SRFC-MA1501-03).

  1. Simulation of the effect of diabatic heating in a case of explosive cyclogenesis in the Eastern Mediterranean with the aid of the model COSMO-GR

    NASA Astrophysics Data System (ADS)

    Kouroutzoglou, John; Avgoustoglou, Evripides; Flocas, Helena A.; Hatzaki, Maria; Karvelis, Haralambos; Keay, Kevin

    2016-04-01

    The effect of low-level diabatic heating is considered as an important factor in the development and evolution of explosive cyclones in the Mediterranean that, however, presents significant differences among different sub-areas and cases. The objective of this study is to assess the ability of the parameterization scheme of the regional non-hydrostatic atmospheric model (COSMO-GR) to simulate the spatial and temporal variations of low-level diabatic heating in a case of explosive cyclogenesis that occurred in the Cyprus area. Model runs are performed for a series of different values of the model parameter "sea roughness" that has proved to significantly affect the simulation of the sea surface fluxes. Then, the derived sea pressure values for each run are compared with observations from surface meteorological stations and ECMWF analyses. It was found that smaller values of the sea roughness parameter compared to the default parameterization, lead to significant enhancement of the magnitude of the surface deepening rates during the explosive deepening period and, thus, to lower minimum pressures that are closer to the observed values. Moreover, the tests demonstrated that the inclusion of latent heat release in the middle troposphere is required to determine a more suitable parameterization of the model physics in order to avoid the underestimation of the thermodynamic mechanisms and, thus, the non-effective evolution of the surface cyclone.

  2. The roles of the shikimate pathway genes, aroA and aroB, in virulence, growth and UV tolerance of Burkholderia glumae strain 411gr-6.

    PubMed

    Karki, Hari Sharan; Ham, Jong Hyun

    2014-12-01

    Burkholderia glumae is the major causal agent of bacterial panicle blight of rice, which is a growing disease problem for rice growers worldwide. In our previous study, some B. glumae strains showed pigmentation phenotypes producing at least two (yellow-green and purple) pigment compounds in casein-peptone-glucose agar medium. The B. glumae strains LSUPB114 and LSUPB116 are pigment-deficient mutant derivatives of the virulent and pigment-proficient strain 411gr-6, having mini-Tn5gus insertions in aroA encoding 3-phosphoshikimate 1-carboxyvinyltransferase and aroB encoding 3-dehydroquinate synthase, respectively. Both enzymes are known to be involved in the shikimate pathway, which leads to the synthesis of aromatic amino acids. Here, we demonstrate that aroA and aroB are required for normal virulence in rice and onion, growth in M9 minimal medium and tolerance to UV light, but are dispensable for the production of the phytotoxin toxoflavin. These results suggest that the shikimate pathway is involved in bacterial pathogenesis by B. glumae without a significant role in the production of toxoflavin, a major virulence factor of this pathogen.

  3. Insertion mutation of the int-1 and int-2 loci by mouse mammary tumor virus in premalignant and malignant neoplasms from the GR mouse strain.

    PubMed Central

    Morris, D W; Barry, P A; Bradshaw, H D; Cardiff, R D

    1990-01-01

    Mouse mammary tumor virus (MMTV)-induced mammary adenocarcinomas can develop from several different premalignant precursors common in GR mice. Insertion mutagenesis of the mammary protooncogenes int-1 and int-2 was studied in this multistep system by analyzing samples from various stages of neoplastic development for novel int-1 and int-2 restriction fragments generated by MMTV provirus integration. int-1 and int-2 insertion mutations were observed in both premalignant lesions and malignant tumors. Some of the tumors with insertion mutations were experimentally derived from insertion mutation-free premalignant precursors. Each class of neoplasm examined had a characteristic frequency of int-1 and int-2 insertion mutations; however, no correspondence was observed between neoplasm morphology and mutation of either gene. These results indicate that insertion mutation of the int-1 and int-2 loci by MMTV provirus can be involved in the earliest identifiable stages of neoplastic development as well as during progression of premalignant lesions to tumors. Insertion mutation of int-1 and int-2 is therefore not stage specific in this system. Images PMID:2157060

  4. Increased neurokinin-1 receptor availability in the amygdala in social anxiety disorder: a positron emission tomography study with [11C]GR205171

    PubMed Central

    Frick, A; Ahs, F; Linnman, C; Jonasson, M; Appel, L; Lubberink, M; Långström, B; Fredrikson, M; Furmark, T

    2015-01-01

    The neurokinin-1 (NK1) receptor is abundantly expressed in the fear circuitry of the brain, including the amygdala, where it modulates stress and anxiety. Despite its proposed involvement in psychopathology, only a few studies of NK1 receptor availability in human subjects with anxiety disorders exist. Here, we compared NK1 receptor availability in patients with social anxiety disorder (SAD; n=17) and healthy controls (n=17) using positron emission tomography and the radiotracer [11C]GR205171. The Patlak Graphical plot using a cerebellar reference region was used to model the influx parameter, Ki measuring NK1 receptor availability. Voxel-wise statistical parametric mapping analyses revealed increased NK1 receptor availability specifically in the right amygdala in SAD patients relative to controls. Thus, we demonstrate that exaggerated social anxiety is related to enhanced NK1 receptor availability in the amygdala. This finding supports the contribution of NK1 receptors not only in animal models of stress and anxiety but also in humans with anxiety disorders. PMID:26151925

  5. In Situ Coupling of Strung Co4N and Intertwined N-C Fibers toward Free-Standing Bifunctional Cathode for Robust, Efficient, and Flexible Zn-Air Batteries.

    PubMed

    Meng, Fanlu; Zhong, Haixia; Bao, Di; Yan, Junmin; Zhang, Xinbo

    2016-08-17

    Flexible power sources with high energy density are crucial for the realization of next-generation flexible electronics. Theoretically, rechargeable flexible zinc-air (Zn-air) batteries could provide high specific energy, while their large-scale applications are still greatly hindered by high cost and resources scarcity of noble-metal-based oxygen evolution reaction (OER)/oxygen reduction reaction (ORR) electrocatalysts as well as inferior mechanical properties of the air cathode. Combining metallic Co4N with superior OER activity and Co-N-C with perfect ORR activity on a free-standing and flexible electrode could be a good step for flexible Zn-air batteries, while lots of difficulties need to be overcome. Herein, as a proof-of-concept experiment, we first propose a strategy for in situ coupling of strung Co4N and intertwined N-C fibers, by pyrolyzation of the novel pearl-like ZIF-67/polypyrrole nanofibers network rooted on carbon cloth. Originating from the synergistic effect of Co4N and Co-N-C and the stable 3D interconnected conductive network structure, the obtained free-standing and highly flexible bifunctional oxygen electrode exhibits excellent electrocatalytic activity and stability for both OER and ORR in terms of low overpotential (310 mV at 10 mA cm(-2)) for OER, a positive half-wave potential (0.8 V) for ORR, and a stable current density retention for at least 20 h, and especially, the obtained Zn-air batteries exhibit a low discharge-charge voltage gap (1.09 V at 50 mA cm(-2)) and long cycle life (up to 408 cycles). Furthermore, the perfect bendable and twistable and rechargeable properties of the flexible Zn-air battery particularly make it a potentially power portable and wearable electronic device.

  6. Sunscreens and T4N5 liposomes differ in their ability to protect against ultraviolet-induced sunburn cell formation, alterations of dendritic epidermal cells, and local suppression of contact hypersensitivity.

    PubMed

    Wolf, P; Cox, P; Yarosh, D B; Kripke, M L

    1995-02-01

    Exposure of skin to ultraviolet (UV) radiation can lead to diverse biologic effects, including inflammation, sunburn cell formation, alterations of cutaneous immune cells, and impaired induction of contact hypersensitivity responses. The molecular mechanisms of these UV-induced effects are not completely understood. We investigated the ability of sunscreens and liposomes containing the DNA excision repair enzyme T4 endonuclease V to prevent these effects of UV radiation. The use of T4N5 liposomes, which increase the repair of cyclobutyl pyrimidine dimers, provides an approach for assessing the role of DNA damage in the effects of UV radiation on the skin. Exposing C3H mice to 500 mJ/cm2 UVB radiation from FS40 sunlamps resulted in skin edema, sunburn cell formation, and morphologic alterations and decreased numbers of Langerhans cells and Thy-1+ dendritic epidermal T cells. In addition, the induction of contact hypersensitivity after application of 2,4-dinitrofluorobenzene on UV-irradiated skin was diminished by 80%. Applying sunscreens containing octyl-N-dimethyl-p-aminobenzoate, 2-ethylhexyl-p-methoxycinnamate, or benzophenone-3 before this dose of UV irradiation gave nearly complete protection against all of these effects of UV irradiation. In contrast, topical application of T4N5 liposomes after UV irradiation had no effect on UV-induced skin edema and only partially protected against sunburn cell formation and local suppression of contact hypersensitivity, although its ability to protect against alterations in dendritic immune cells was comparable to that of the sunscreens. These results suggest that DNA damage is involved in only some of the local effects of UV radiation on the skin. In addition, T4N5 liposomes may be a useful adjunct to sunscreens because they can reduce some of the deleterious effects of UV radiation on skin even after a sunburn has been initiated. PMID:7829886

  7. Synthesis and Mechanical Wear Studies of Ultra Smooth Nanostructured Diamond (USND) Coatings Deposited by Microwave Plasma Chemical Vapor Deposition with He/H2/CH4/N2 Mixtures

    PubMed Central

    Chowdhury, S.; Borham, J.; Catledge, S. A.; Eberhardt, A. W.; Johnson, P. S.; Vohra, Y. K.

    2008-01-01

    Ultra smooth nanostructured diamond (USND) coatings were deposited by microwave plasma chemical vapor deposition (MPCVD) technique using He/H2/CH4/N2 gas mixture. The RMS surface roughness as low as 4 nm (2 micron square area) and grain size of 5–6 nm diamond coatings were achieved on medical grade titanium alloy. Previously it was demonstrated that the C2 species in the plasma is responsible for the production of nanocrystalline diamond coatings in the Ar/H2/CH4 gas mixture. In this work we have found that CN species is responsible for the production of USND coatings in He/H2/CH4/N2 plasma. It was found that diamond coatings deposited with higher CN species concentration (normalized by Balmer Hα line) in the plasma produced smoother and highly nanostructured diamond coatings. The correlation between CN/Hα ratios with the coating roughness and grain size were also confirmed with different set of gas flows/plasma parameters. It is suggested that the presence of CN species could be responsible for producing nanocrystallinity in the growth of USND coatings using He/H2/CH4/N2 gas mixture. The RMS roughness of 4 nm and grain size of 5–6 nm were calculated from the deposited diamond coatings using the gas mixture which produced the highest CN/Hα species in the plasma. Wear tests were performed on the OrthoPOD®, a six station pin-on-disk apparatus with ultra-high molecular weight polyethylene (UHMWPE) pins articulating on USND disks and CoCrMo alloy disk. Wear of the UHMWPE was found to be lower for the polyethylene on USND than that of polyethylene on CoCrMo alloy. PMID:19112519

  8. In Situ Coupling of Strung Co4N and Intertwined N-C Fibers toward Free-Standing Bifunctional Cathode for Robust, Efficient, and Flexible Zn-Air Batteries.

    PubMed

    Meng, Fanlu; Zhong, Haixia; Bao, Di; Yan, Junmin; Zhang, Xinbo

    2016-08-17

    Flexible power sources with high energy density are crucial for the realization of next-generation flexible electronics. Theoretically, rechargeable flexible zinc-air (Zn-air) batteries could provide high specific energy, while their large-scale applications are still greatly hindered by high cost and resources scarcity of noble-metal-based oxygen evolution reaction (OER)/oxygen reduction reaction (ORR) electrocatalysts as well as inferior mechanical properties of the air cathode. Combining metallic Co4N with superior OER activity and Co-N-C with perfect ORR activity on a free-standing and flexible electrode could be a good step for flexible Zn-air batteries, while lots of difficulties need to be overcome. Herein, as a proof-of-concept experiment, we first propose a strategy for in situ coupling of strung Co4N and intertwined N-C fibers, by pyrolyzation of the novel pearl-like ZIF-67/polypyrrole nanofibers network rooted on carbon cloth. Originating from the synergistic effect of Co4N and Co-N-C and the stable 3D interconnected conductive network structure, the obtained free-standing and highly flexible bifunctional oxygen electrode exhibits excellent electrocatalytic activity and stability for both OER and ORR in terms of low overpotential (310 mV at 10 mA cm(-2)) for OER, a positive half-wave potential (0.8 V) for ORR, and a stable current density retention for at least 20 h, and especially, the obtained Zn-air batteries exhibit a low discharge-charge voltage gap (1.09 V at 50 mA cm(-2)) and long cycle life (up to 408 cycles). Furthermore, the perfect bendable and twistable and rechargeable properties of the flexible Zn-air battery particularly make it a potentially power portable and wearable electronic device. PMID:27463122

  9. Assembly of polymeric silver(I) complexes of isomeric phenylenediethynides with the supramolecular synthons Agn subset C2-R-C2 superset Agn (R = p-, m-, o-C6H4; n = 4, 5).

    PubMed

    Zhao, Liang; Mak, Thomas C W

    2005-11-01

    New Agn subset C2-R-C2 supersetAgn (R = p-, m-, o-C6H4; n = 4, 5) supramolecular synthons have been explored in the coordination network assembly of silver(I) complexes of the isomeric phenylenediethynides. An