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Sample records for 12x fiv pr

  1. Crystal Structure of An FIV/HIV Chimeric Protease Complexed With the Broad-Based Inhibitor, TL-3

    SciTech Connect

    Heaslet, H.; Lin, Y.-C.; Tam, K.; Torbett, B.E.; Elder, J.E.; Stout, C.D.; /Pfizer Global Res. Devel. /Scripps Res. Inst.

    2007-07-09

    We have obtained the 1.7 angstrom crystal structure of FIV protease (PR) in which 12 critical residues around the active site have been substituted with the structurally equivalent residues of HIV PR (12X FIV PR). The chimeric PR was crystallized in complex with the broad-based inhibitor TL-3, which inhibits wild type FIV and HIV PRs, as well as 12X FIV PR and several drug-resistant HIV mutants [1-4]. Biochemical analyses have demonstrated that TL-3 inhibits these PRs in the order HIV PR > 12X FIV PR > FIV PR, with Ki values of 1.5 nM, 10 nM, and 41 nM, respectively [2-4]. Comparison of the crystal structures of the TL-3 complexes of 12X FIV and wild-typeFIV PR revealed the formation of additional van der Waals interactions between the enzyme inhibitor in the mutant PR. The 12X FIV PR retained the hydrogen bonding interactions between residues in the flap regions and active site involving the enzyme and the TL-3 inhibitor in comparison to both FIV PR and HIV PR. However, the flap regions of the 12X FIV PR more closely resemble those of HIV PR, having gained several stabilizing intra-flap interactions not present in wild type FIV PR. These findings offer a structural explanation for the observed inhibitor/substrate binding properties of the chimeric PR.

  2. Diagnosing feline immunodeficiency virus (FIV) infection in FIV-vaccinated and FIV-unvaccinated cats using saliva.

    PubMed

    Westman, Mark E; Malik, Richard; Hall, Evelyn; Norris, Jacqueline M

    2016-06-01

    We recently showed that two immunochromatography point-of-care FIV antibody test kits (Witness FeLV/FIV and Anigen Rapid FIV/FeLV) were able to correctly assign FIV infection status, irrespective of FIV vaccination history, using whole blood as the diagnostic specimen. A third FIV antibody test kit, SNAP FIV/FeLV Combo (an enzyme-linked immunosorbent assay [ELISA]), was unable to differentiate antibodies produced in response to FIV vaccination from those incited by FIV infection. The aim of this study was to determine if saliva is a suitable diagnostic specimen using the same well characterized feline cohort. FIV infection status of these cats had been determined previously using a combination of serology, polymerase chain reaction (PCR) testing and virus isolation. This final assignment was then compared to results obtained using saliva as the diagnostic specimen utilizing the same three point-of-care FIV antibody test kits and commercially available PCR assay (FIV RealPCR). In a population of cats where one third (117/356; 33%) were FIV-vaccinated, both immunochromatography test kits accurately diagnosed FIV infection using saliva via a centrifugation method, irrespective of FIV vaccination history. For FIV diagnosis using saliva, the specificity of Anigen Rapid FIV/FeLV and Witness FeLV/FIV was 100%, while the sensitivity of these kits was 96% and 92% respectively. SNAP FIV/FeLV Combo respectively. SNAP FIV/FeLV Combo had a specificity of 98% and sensitivity of 44%, while FIV RealPCR testing had a specificity of 100% and sensitivity of 72% using saliva. A revised direct method of saliva testing was trialed on a subset of FIV-infected cats (n=14), resulting in 14, 7 and 0 FIV positive results using Anigen Rapid FIV/FeLV, Witness FeLV/FIV and SNAP FIV/FeLV Combo, respectively. These results demonstrate that saliva can be used to diagnose FIV infection, irrespective of FIV vaccination history, using either a centrifugation method (Anigen Rapid FIV/FeLV and Witness

  3. Effect of pr and ca Doping on the Superconducting Properties of Dy1-2xPrxCaxBa2Cu3O7-δ HTSCs

    NASA Astrophysics Data System (ADS)

    Charoenthai, N.; Udomkan, N.

    The structure changes and the suppression of superconductivity in the Dy-123 high-temperature superconductors (HTSCs) due to equal substitution of Pr and Ca are studied. The onset temperatures (Tc's) of the co-doped Dy1-2xPrxCaxBa2Cu3O7-δ HTSC's are measured by AC susceptibility measurements. The Tc's and rates of decrease of dTc/dx due to Pr substitution for both series exhibit rare earth size effects. It is found that the lattice distortion defined by D = (b-a)/(b+a), where a and b are the lattice parameters in the basal plane, decreases systematically as the doping is increased. A hole-filling and pair-breaking model is used to explain the behaviors of both the Tc's and the rates of decrease of dTc/dx as Pr4+ ions are doped into two "123" HTSCs.

  4. Structural basis for drug and substrate specificity exhibited by FIV encoding a chimeric FIV/HIV protease

    SciTech Connect

    Lin, Ying-Chuan; Perryman, Alexander L.; Olson, Arthur J.; Torbett, Bruce E.; Elder, John H.; Stout, C. David

    2011-06-01

    Crystal structures of the 6s-98S FIV protease chimera with darunavir and lopinavir bound have been determined at 1.7 and 1.8 Å resolution, respectively. A chimeric feline immunodeficiency virus (FIV) protease (PR) has been engineered that supports infectivity but confers sensitivity to the human immunodeficiency virus (HIV) PR inhibitors darunavir (DRV) and lopinavir (LPV). The 6s-98S PR has five replacements mimicking homologous residues in HIV PR and a sixth which mutated from Pro to Ser during selection. Crystal structures of the 6s-98S FIV PR chimera with DRV and LPV bound have been determined at 1.7 and 1.8 Å resolution, respectively. The structures reveal the role of a flexible 90s loop and residue 98 in supporting Gag processing and infectivity and the roles of residue 37 in the active site and residues 55, 57 and 59 in the flap in conferring the ability to specifically recognize HIV PR drugs. Specifically, Ile37Val preserves tertiary structure but prevents steric clashes with DRV and LPV. Asn55Met and Val59Ile induce a distinct kink in the flap and a new hydrogen bond to DRV. Ile98Pro→Ser and Pro100Asn increase 90s loop flexibility, Gln99Val contributes hydrophobic contacts to DRV and LPV, and Pro100Asn forms compensatory hydrogen bonds. The chimeric PR exhibits a comparable number of hydrogen bonds, electrostatic interactions and hydrophobic contacts with DRV and LPV as in the corresponding HIV PR complexes, consistent with IC{sub 50} values in the nanomolar range.

  5. Detection of feline immunodeficiency virus (FIV) nucleic acids in FIV-seronegative cats.

    PubMed Central

    Dandekar, S; Beebe, A M; Barlough, J; Phillips, T; Elder, J; Torten, M; Pedersen, N

    1992-01-01

    A study was undertaken to determine the rate of viral transmission among naive specific-pathogen-free (SPF) cats living in close contact with feline immunodeficiency virus (FIV)-infected cats. Twenty SPF cats were housed in the same rooms with experimentally FIV-infected seropositive and virus culture-positive cats for 2 to 4 years and were monitored for the presence of FIV nucleic acids and antibodies. Only 1 of the 20 cats became seropositive and virus culture positive and developed signs of disease. Genomic DNA from bone marrow and peripheral blood mononuclear cells (PBMC) of 10 of 19 healthy-appearing seronegative cats became positive for FIV DNA by the polymerase chain reaction. Twenty-eight SPF cats housed as groups in separate quarters and never exposed to FIV-infected cats were uniformly negative for FIV DNA. FIV RNA transcripts were detected in concanavalin A-stimulated PBMC cultures from 4 of 10 FIV DNA-positive, seronegative cats by in situ hybridization. PBMC from three of four naive SPF cats acquired FIV nucleic acids after the cats were transfused with blood and bone marrow from FIV genome-positive, seronegative donors. Three of five FIV-seronegative cats housed for years with naturally FIV-infected cats in a private household were also found to harbor FIV DNA, indicating that the same phenomenon occurred in the field. These findings demonstrate that cats living in close contact with FIV-infected seropositive cats can acquire FIV nucleic acids without developing detectable levels of serum antibodies or disease. Images PMID:1318395

  6. Determining the feline immunodeficiency virus (FIV) status of FIV-vaccinated cats using point-of-care antibody kits.

    PubMed

    Westman, Mark E; Malik, Richard; Hall, Evelyn; Sheehy, Paul A; Norris, Jacqueline M

    2015-10-01

    This study challenges the commonly held view that the feline immunodeficiency virus (FIV) infection status of FIV-vaccinated cats cannot be determined using point-of-care antibody test kits due to indistinguishable antibody production in FIV-vaccinated and naturally FIV-infected cats. The performance of three commercially available point-of-care antibody test kits was compared in a mixed population of FIV-vaccinated (n=119) and FIV-unvaccinated (n=239) cats in Australia. FIV infection status was assigned by considering the results of all antibody kits in concert with results from a commercially available PCR assay (FIV RealPCR™). Two lateral flow immunochromatography test kits (Witness FeLV/FIV; Anigen Rapid FIV/FeLV) had excellent overall sensitivity (100%; 100%) and specificity (98%; 100%) and could discern the true FIV infection status of cats, irrespective of FIV vaccination history. The lateral flow ELISA test kit (SNAP FIV/FeLV Combo) could not determine if antibodies detected were due to previous FIV vaccination, natural FIV infection, or both. The sensitivity and specificity of FIV RealPCR™ for detection of viral and proviral nucleic acid was 92% and 99%, respectively. These results will potentially change the way veterinary practitioners screen for FIV in jurisdictions where FIV vaccination is practiced, especially in shelter scenarios where the feasibility of mass screening is impacted by the cost of testing. PMID:26459979

  7. The normal state Hall effect in Nd 1-2 xCa xM xBa 2Cu 3O 7- δ (M = Pr, Th): Evidence for hole localization by disorder

    NASA Astrophysics Data System (ADS)

    Ghorbani, S. R.; Andersson, M.; Rapp, Ö.

    2005-08-01

    The transport properties of sintered samples of Nd1-2xCaxMxBa2Cu3O7-δ (M = Pr, Th) with 0 ⩽ x ⩽ 0.10 have been studied in the normal state by Hall effect measurements. The Hall coefficient at high temperature was almost constant for Ca-Pr while it increased with increasing Ca-Th doping concentration. The results for the Hall coefficient as a function of temperature and doping concentration were analyzed within two different models. A good agreement between models and data was obtained. On the basis of these models, it was inferred that Ca-Pr and Ca-Th doping introduce electronic disorder in the CuO2 planes. The localization tendency is driven by electronic disorder. This is the main reason for strong depression of the superconducting critical temperature in both alloys. It was found that the Hall angle is proportional to T2 in the whole measured temperature range in Ca-Pr doped samples while there are deviations at high temperature in the Ca-Th doped series. In a phenomenological narrow band model, the conduction band was asymmetric for the pure sample and this asymmetry decreased with increasing Ca-Th doping while it was almost constant for Ca-Pr doped samples.

  8. FIV vaccine development and its importance to veterinary and human medicine: a review FIV vaccine 2002 update and review.

    PubMed

    Uhl, E W; Heaton-Jones, T G; Pu, R; Yamamoto, J K

    2002-12-01

    Feline immunodeficiency virus (FIV) is a natural infection of domestic cats that results in acquired immunodeficiency syndrome resembling human immunodeficiency virus (HIV) infection in humans. The worldwide prevalence of FIV infection in domestic cats has been reported to range from 1 to 28%. Hence, an effective FIV vaccine will have an important impact on veterinary medicine in addition to being used as a small animal AIDS model for humans. Since the discovery of FIV reported in 1987, FIV vaccine research has pursued both molecular and conventional vaccine approaches toward the development of a commercial product. Published FIV vaccine trial results from 1998 to the present have been compiled to update the veterinary clinical and research communities on the immunologic and experimental efficacy status of these vaccines. A brief report is included on the outcome of the 10 years of collaborative work between industry and academia which led to recent USDA approval of the first animal lentivirus vaccine, the dual-subtype FIV vaccine. The immunogenicity and efficacy of the experimental prototype, dual-subtype FIV vaccine and the efficacy of the currently approved commercial, dual-subtype FIV vaccine (Fel-O-Vax FIV) are discussed. Potential cross-reactivity complications between commercial FIV diagnostic tests, Idexx Snap Combo Test and Western blot assays, and sera from previously vaccinated cats are also discussed. Finally, recommendations are made for unbiased critical testing of new FIV vaccines, the currently USDA approved vaccine, and future vaccines in development. PMID:12459160

  9. Simple in vitro methods for titrating feline immunodeficiency virus (FIV) and FIV neutralizing antibodies.

    PubMed

    Tozzini, F; Matteucci, D; Bandecchi, P; Baldinotti, F; Poli, A; Pistello, M; Siebelink, K H; Ceccherini-Nelli, L; Bendinelli, M

    1992-06-01

    The feline immunodeficiency virus (FIV) readily produced syncytia in Crandell feline kidney (CrFK) cells adapted to a medium containing 0.5% fetal calf serum, a variety of growth factors and other supplements. This finding has been exploited to develop simple and sensitive virus titration and neutralization assays. High titre neutralizing antibodies were detected in cats infected naturally and experimentally with FIV, but not in uninfected animals.

  10. Characterization of regionally associated feline immunodeficiency virus (FIV) in bobcats (Lynx rufus).

    PubMed

    Lagana, Danielle M; Lee, Justin S; Lewis, Jesse S; Bevins, Sarah N; Carver, Scott; Sweanor, Linda L; McBride, Roy; McBride, Caleb; Crooks, Kevin R; VandeWoude, Sue

    2013-07-01

    Feline immunodeficiency virus (FIV) classically infects felid species with highly divergent species-specific FIVs. However, recent studies have detected an FIV strain infecting both bobcats (Lynx rufus) and pumas (Puma concolor) in California and Florida. To further investigate this observation, we evaluated FIV from bobcats in Florida (n=25) and Colorado (n=80) between 2008 and 2011. Partial viral sequences from five Florida bobcats cluster with previously published sequences from Florida panthers. We did not detect FIV in Colorado bobcats.

  11. A Detailed Phylogenetic Analysis of FIV in the United States

    PubMed Central

    Weaver, Eric A.

    2010-01-01

    Background Feline immunodeficiency virus (FIV) is a lentivirus associated with AIDS-like illnesses in cats and has been used as a model for the study of human immunodeficiency virus (HIV). A feature of HIV and FIV infection is the continually increasing divergence among viral isolates between different individuals, as well as within the same individuals. Methodology/Principal Findings The goal of this study was to determine the phylogenetic patterns of viral isolates obtained within the United States (U.S.) by focusing on the variable, V3-V4, region of the FIV envelope gene. Conclusions/Significance Data indicate that FIV, from within the U.S., localize to four viral clades, A, B, C, and F. Also shown is the geographic isolation of strains where clade A and clade B are found predominately on the west coast; however, clade B is also found throughout the U.S. and represents the predominant clade. This study presents a complete and conclusive analysis of FIV isolates from within the U.S. and may be used as the essential basis for the development of an effective multi-clade vaccine. PMID:20711253

  12. Immunomodulator expression in trophoblasts from the feline immunodeficiency virus FIV infected cat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    FIV infection frequently compromises pregnancy under experimental conditions and is accompanied by aberrant expression of some placental cytokines. Trophoblasts produce numerous immunomodulators that play a role in placental development and pregnancy maintenance. We hypothesized that FIV infection m...

  13. Cortical neuronal cytoskeletal changes associated with FIV infection

    NASA Technical Reports Server (NTRS)

    Jacobson, S.; Henriksen, S. J.; Prospero-Garcia, O.; Phillips, T. R.; Elder, J. H.; Young, W. G.; Bloom, F. E.; Fox, H. S.

    1997-01-01

    HIV-1 infection is often complicated by central nervous system (CNS) dysfunction. Degenerative neuronal changes as well as neuronal loss have been documented in individuals with AIDS. Feline immunodeficiency virus (FIV) infection of cats provides a model for both the immune and the central nervous system manifestations of HIV infection of humans. In this study we have examined neurons in the frontal cortex of feline immunodeficiency virus-infected cats and controls for immunoreactivity with SMI 32, an antibody recognizing a non-phosphorylated epitope on neurofilaments. We noted a significant increase in the number of immunoreactive pyramidal cells in infected animals compared to controls. The changes seen in the neuronal cytoskeleton as a consequence of the inoculation with FIV were similar to those seen in humans undergoing the normal aging process as well as those suffering from neurological diseases, including Alzheimer's and dementia pugilistica. The changes we noted in the feline brain were also similar to that reported in animals with traumatic injuries or with spontaneously occurring or induced motor neuron diseases, suggesting that the increase in reactivity represents a deleterious effect of FIV on the central nervous system.

  14. Identification of three feline immunodeficiency virus (FIV) env gene subtypes and comparison of the FIV and human immunodeficiency virus type 1 evolutionary patterns.

    PubMed Central

    Sodora, D L; Shpaer, E G; Kitchell, B E; Dow, S W; Hoover, E A; Mullins, J I

    1994-01-01

    Feline immunodeficiency virus (FIV) is a lentivirus associated with AIDS-like illnesses in cats. As such, FIV appears to be a feline analog of human immunodeficiency virus (HIV). A hallmark of HIV infection is the large degree of viral genetic diversity that can develop within an infected individual and the even greater and continually increasing level of diversity among virus isolates from different individuals. Our goal in this study was to determine patterns of FIV genetic diversity by focusing on a 684-nucleotide region encompassing variable regions V3, V4, and V5 of the FIV env gene in order to establish parallels and distinctions between FIV and HIV type 1 (HIV-1). Our data demonstrate that, like HIV-1, FIV can be separated into distinct envelope sequence subtypes (three are described here). Similar to that found for HIV-1, the pairwise sequence divergence within an FIV subtype ranged from 2.5 to 15.0%, whereas that between subtypes ranged from 17.8 to 26.2%. However, the high number of synonymous nucleotide changes among FIV V3 to V5 env sequences may also include a significant number of back mutations and suggests that the evolutionary distances among FIV subtypes are underestimated. Although only a few subtype B viruses were available for examination, the pattern of diversity between the FIV A and B subtypes was found to be significantly distinct; subtype B sequences had proportionally fewer mutations that changed amino acids, compared with silent changes, suggesting a more advanced state of adaptation to the host. No similar distinction was evident for HIV-1 subtypes. The diversity of FIV genomes within individual infected cats was found to be as high as 3.7% yet twofold lower than that within HIV-1-infected people over a comparable region of the env gene. Despite these differences, significant parallels between patterns of FIV evolution and HIV-1 evolution exist, indicating that a wide array of potentially divergent virus challenges need to be considered

  15. Neutralising antibody response in domestic cats immunised with a commercial feline immunodeficiency virus (FIV) vaccine

    PubMed Central

    Bęczkowski, Paweł M.; Harris, Matthew; Techakriengkrai, Navapon; Beatty, Julia A.; Willett, Brian J.; Hosie, Margaret J.

    2015-01-01

    Across human and veterinary medicine, vaccines against only two retroviral infections have been brought to market successfully, the vaccines against feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV). FeLV vaccines have been a global success story, reducing virus prevalence in countries where uptake is high. In contrast, the more recent FIV vaccine was introduced in 2002 and the degree of protection afforded in the field remains to be established. However, given the similarities between FIV and HIV, field studies of FIV vaccine efficacy are likely to advise and inform the development of future approaches to HIV vaccination. Here we assessed the neutralising antibody response induced by FIV vaccination against a panel of FIV isolates, by testing blood samples collected from client-owned vaccinated Australian cats. We examined the molecular and phenotypic properties of 24 envs isolated from one vaccinated cat that we speculated might have become infected following natural exposure to FIV. Cats vaccinated against FIV did not display broadly neutralising antibodies, suggesting that protection may not extend to some virulent recombinant strains of FIV circulating in Australia. PMID:25613718

  16. Neutralising antibody response in domestic cats immunised with a commercial feline immunodeficiency virus (FIV) vaccine.

    PubMed

    Bęczkowski, Paweł M; Harris, Matthew; Techakriengkrai, Navapon; Beatty, Julia A; Willett, Brian J; Hosie, Margaret J

    2015-02-18

    Across human and veterinary medicine, vaccines against only two retroviral infections have been brought to market successfully, the vaccines against feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV). FeLV vaccines have been a global success story, reducing virus prevalence in countries where uptake is high. In contrast, the more recent FIV vaccine was introduced in 2002 and the degree of protection afforded in the field remains to be established. However, given the similarities between FIV and HIV, field studies of FIV vaccine efficacy are likely to advise and inform the development of future approaches to HIV vaccination. Here we assessed the neutralising antibody response induced by FIV vaccination against a panel of FIV isolates, by testing blood samples collected from client-owned vaccinated Australian cats. We examined the molecular and phenotypic properties of 24 envs isolated from one vaccinated cat that we speculated might have become infected following natural exposure to FIV. Cats vaccinated against FIV did not display broadly neutralising antibodies, suggesting that protection may not extend to some virulent recombinant strains of FIV circulating in Australia.

  17. Disseminated Mycobacterium genavense infection in a FIV-positive cat.

    PubMed

    Hughes, M S; Ball, N W; Love, D N; Canfield, P J; Wigney, D I; Dawson, D; Davis, P E; Malik, R

    1999-03-01

    An 8-year-old FIV-positive Australian cat was presented with coughing, periocular alopecia, pyrexia and inappetence. Skin scrapings demonstrated Demodex cati mites. Antibiotics were administered and it was treated successfully for periocular demodectic mange, but the cat continued to exhibit respiratory signs and lose weight. Further investigation revealed an ascarid infection and active chronic inflammation of undetected cause affecting the lower airways. Repetitive treatment with pyrantel failed to eradicate the ascarid infection. The cat became cachectic and developed moist ulcerative dermatitis of the neck, severe non-regenerative anaemia, leucopenia and thrombocytopenia. Necropsy and histopathology revealed mycobacteriosis affecting skin, lungs, spleen, lymph nodes, liver and kidney. Attempted culture of frozen tissues at a mycobacteria reference laboratory was unsuccessful. Paraffin-embedded, formalin-fixed tissue was retrieved and examined using PCR to amplify part of the 16S rRNA gene. A diagnosis of disseminated Mycobacterium genavense infection was made based on the presence of acid fast bacteria in many tissues and partial sequence of the 16S rRNA gene. Although M genavense has been identified previously as a cause of disseminated disease in AIDS patients, this is the first report of infection in a cat. It was suspected that the demodecosis, recurrent ascarid infections and disseminated M genavense infection resulted from an immune deficiency syndrome consequent to longstanding FIV infection.

  18. Effect of chronic FIV infection, and efficacy of marbofloxacin treatment, on Mycoplasma haemofelis infection.

    PubMed

    Tasker, Séverine; Caney, Sarah M A; Day, Michael J; Dean, Rachel S; Helps, Chris R; Knowles, Toby G; Lait, Philippa J P; Pinches, Mark D G; Gruffydd-Jones, Timothy J

    2006-10-31

    The purpose of this study was to investigate the effect of chronic feline immunodeficiency virus (FIV) infection, and efficacy of marbofloxacin treatment, on Mycoplasma haemofelis infection. Six cats chronically infected with FIV-Glasgow8 (Group X) and six FIV-free cats (Group Y) were infected with M. haemofelis on Day 0 by intravenous blood inoculation. From Day 0 until Day 86 post-infection (pi), blood samples were collected for M. haemofelis and FIV provirus quantitative real-time PCR and haematology. Three of the six cats in each of Groups X and Y were randomly selected to receive marbofloxacin treatment (2 mg/kg PO q24 h) from Day 16 to 43 pi, with the remaining cats being untreated controls with no antibiotic treatment. The M. haemofelis copy numbers and haematological data were compared between Groups X and Y, and between marbofloxacin-treated and control cats using a Mann-Whitney U-test. M. haemofelis infection was associated with development of macrocytic hypochromic anaemia. In some cats, marked variation in M. haemofelis copy number over time (>100,000-fold difference within 48 h in some cats) and/or cycling of copy number was seen. No correlation was found between FIV provirus copy number and M. haemofelis copy number or haematological variables. No significant effect of chronic FIV infection on M. haemofelis copy number kinetics or haematological changes due to M. haemofelis infection was found, other than MCHC (P=0.03). Marbofloxacin treatment was associated with a significant decrease in M. haemofelis copy number (P=0.002), although consistent clearance of infection was not demonstrated. This study reveals the presence of marked fluctuations in M. haemofelis copy number kinetics in vivo and a significant response to marbofloxacin antibiotic treatment.

  19. HIV- and FIV-derived gp120 alter spatial memory, LTP, and sleep in rats.

    PubMed

    Sánchez-Alavez, M; Criado, J; Gómez-Chavarín, M; Jiménez-Anguiano, A; Navarro, L; Díaz-Ruiz, O; Galicia, O; Sánchez-Narváez, F; Murillo-Rodríguez, E; Henriksen, S J; Elder, J H; Prospéro-García, O

    2000-08-01

    Human immunodeficiency virus (HIV)-associated dementia (HAD) has been detected in 20-30% of patients suffering AIDS. The envelope glycoprotein 120 (gp120) derived from HIV seems to play a critical role in the pathophysiology of this dementia. Likewise, the feline immunodeficiency virus (FIV)-derived gp120 causes neurological and electrophysiological abnormalitites in cats. We have studied the effects of gp120 derived from HIV or FIV on learning and memory processing, hippocampal long-term potentiation (LTP), hippocampal neuronal cAMP production, the sleep-waking cycle, and locomotor activity and equilibrium in rats. Results showed that while both HIV- and FIV-gp120 impaired the rat's performance in the Barnes maze task, only HIVgp120 impaired the induction and maintenance of LTP. However, both glycoproteins induced a significant decrease in the posttetanic potentiation. HIVgp120 also caused a significant reduction in cAMP production in the hippocampus. Regarding the sleep-waking cycle, HIV- and FIV-gp120 increased the waking state and slow-wave sleep 1 (SWS1), while decreasing both SWS2 and REM sleep. Locomotor activity and equilibrium were significantly altered by these glycoproteins. These results suggest that HIVgp120 causes neurophysiological abnormalities and therefore may facilitate HAD development in AIDS patients.

  20. PATHOLOGICAL MANIFESTATIONS OF FELINE IMMUNODEFICIENCY VIRUS (FIV) INFECTION IN WILD AFRICAN LIONS

    PubMed Central

    Roelke, Melody E.; Brown, Meredith A.; Troyer, Jennifer L.; Winterbach, Hanlie; Winterbach, Christiaan; Hemson, Graham; Smith, Dahlem; Johnson, Randall C.; Pecon-Slattery, Jill; Roca, Alfred L.; Alexander, Katherine; Klein, Lin; Martinelli, Paulo; Krishnasamu, Karthiuani; O'Brien, Stephen J.

    2009-01-01

    Feline immunodeficiency virus (FIV) causes AIDS in the domestic cat (Felis catus) but has not been explicitly associated with AIDS pathology in any of the eight free-ranging species of Felidae that are endemic with circulating FIV strains. African lion (Panthera leo) populations are infected with lion-specific FIV strains (FIVple), yet there remains uncertainty about the degree to which FIV infection impacts their health. Reported CD4+ T-lymphocyte depletion in FIVple infected lions and anecdotal reports of lion morbidity associated with FIV sero-prevalence emphasize the concern as to whether FIVple is innocuous or pathogenic. Here we monitored clinical, biochemical, histological and serological parameters among FIVple-positive (N=47) as compared to FIVple negative (N=17) lions anesthetized and sampled on multiple occasions between 1999 and 2006 in Botswana. Relative to uninfected lions, FIVple infected lions displayed a significant elevation in the prevalence of AIDS defining conditions: lymphandenopathy, gingivitis, tongue papillomas, dehydration, and poor coat condition, as well as displaying abnormal red blood cell parameters and elevated liver enzymes and serum proteins. Spleen and lymph node laparoscopic biopsies from free-ranging FIVple infected lions (N=8) revealed evidence of lymphoid depletion, the hallmark pathology documented in immunodefieciency virus infections of humans (HIV-1), macaques, and domestic cats. We conclude that over time FIVple infections in free-ranging lions can lead to adverse clinical, immunological, and pathological outcomes in some individuals that parallel sequelae caused by lentivirus infection in humans (HIV), Asian macaques (SIV) and domestic cats (FIVfca). PMID:19464039

  1. 7. CLOSEUP VIEW OF WASHED UP 12' x 12' DAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. CLOSE-UP VIEW OF WASHED UP 12' x 12' DAM SUPPORT TIMBERS, THREE BEARS LAKE, LOOKING NORTHEAST FROM SOUTH SIDE OF LAKE - Three Bears Lake & Dams, North of Marias Pass, East Glacier Park, Glacier County, MT

  2. Renal alterations in feline immunodeficiency virus (FIV)-infected cats: a natural model of lentivirus-induced renal disease changes.

    PubMed

    Poli, Alessandro; Tozon, Natasa; Guidi, Grazia; Pistello, Mauro

    2012-09-01

    Human immunodeficiency virus (HIV) is associated with several renal syndromes including acute and chronic renal failures, but the underlying pathogenic mechanisms are unclear. HIV and feline immunodeficiency virus (FIV) share numerous biological and pathological features, including renal alterations. We investigated and compared the morphological changes of renal tissue of 51 experimentally and 21 naturally infected cats. Compared to the latter, the experimentally infected cats exhibited some mesangial widening and glomerulonephritis, milder proteinuria, and lower tubular and interstitial alterations. The numbers of giant protein tubular casts and tubular microcysts were also lower. In contrast, diffuse interstitial infiltrates and glomerular and interstitial amyloidosis were detected only in naturally infected cats. Similar alterations are found in HIV infected patients, thus supporting the idea of a causative role of FIV infection in renal disease, and underlining the relevance of the FIV and its natural host as an animal model for investigating lentivirus-associated nephropathy. PMID:23170163

  3. Renal Alterations in Feline Immunodeficiency Virus (FIV)-Infected Cats: A Natural Model of Lentivirus-Induced Renal Disease Changes

    PubMed Central

    Poli, Alessandro; Tozon, Natasa; Guidi, Grazia; Pistello, Mauro

    2012-01-01

    Human immunodeficiency virus (HIV) is associated with several renal syndromes including acute and chronic renal failures, but the underlying pathogenic mechanisms are unclear. HIV and feline immunodeficiency virus (FIV) share numerous biological and pathological features, including renal alterations. We investigated and compared the morphological changes of renal tissue of 51 experimentally and 21 naturally infected cats. Compared to the latter, the experimentally infected cats exhibited some mesangial widening and glomerulonephritis, milder proteinuria, and lower tubular and interstitial alterations. The numbers of giant protein tubular casts and tubular microcysts were also lower. In contrast, diffuse interstitial infiltrates and glomerular and interstitial amyloidosis were detected only in naturally infected cats. Similar alterations are found in HIV infected patients, thus supporting the idea of a causative role of FIV infection in renal disease, and underlining the relevance of the FIV and its natural host as an animal model for investigating lentivirus-associated nephropathy. PMID:23170163

  4. Design, fabrication, and characterization of polymeric bioMEMS for the detection of feline immunodeficiency virus (FIV)

    NASA Astrophysics Data System (ADS)

    Cohen, Brian; Gadre, Anand; Kaloyeros, Alain E.

    2007-02-01

    This project comprises the development of a novel polymeric BioMEMS device capable of rapidly detecting FIV in a minimally invasive manner. FIV severely inhibits the infected feline from mounting an immune response, and causes susceptibility to other types of diseases. Vaccines against FIV do exist, but have some strong limitations to their effectiveness; so early detection is the best method to combat the spread of the disease. Current testing methods look for antibodies to the FIV protein p24 in feline blood using established Enzyme Linked ImmunoSorbent Assay (ELISA) protocols. The focus of this research is to design and construct a device that can detect antibodies to p24 in a salivary sample by non-intrusive electrochemical means. The device is constructed upon a silicon substrate with gold microelectrodes coated with polypyrrole (PPy), an electrically conducting and biocompatible polymer. In the current phase of the research, the PPy deposition process has been optimized with regards to film thickness, uniformity and conductivity. Microfluidic channels have been fabricated using SU-8, an epoxy based polymer that enables the test sample and other solutions to pass freely through the device. The PPy will be coated with anti-FIV p24 antibodies that can capture FIV p24 antigens present in a salivary sample. Future research will involve the analysis of PPy/antibody interaction and its effect on functionality. The capture of such antigens will interfere with a reduction-oxidation (redox) reaction in a subsequently added ionic solution. This interference will change the characteristic resistance of the solution yielding a qualitative test for the presence of the viral antigens in the sample and hence determining the occurrence of infection.

  5. Pulmonary cryptococcosis and Capillaria aerophila infection in an FIV-positive cat.

    PubMed

    Barrs, V R; Martin, P; Nicoll, R G; Beatty, J A; Malik, R

    2000-03-01

    A 12-year-old, FIV-positive, domestic longhair cat was presented with a history of sneezing and coughing during the previous seven months. On thoracic radiographs, a prominent bronchial pattern and three focal, opacified nodules were seen. Cytology of bronchoalveolar lavage fluid demonstrated spherical, capsulate, narrow-necked, budding yeasts within macrophages. Culture of the fluid yielded a heavy growth of Cryptococcus neoformans var neoformans. The serum latex cryptococcal antigen agglutination test titre was 158. The cat was treated with itraconazole and the cough resolved over a 5-month period but then recurred. Repeat thoracic radiographs showed resolution of the pulmonary nodules but a persistent bronchial pattern. Adult nematodes and ova with morphology characteristic of Capillaria aerophila were seen in bronchoalveolar lavage fluid and no yeasts were cultured from the fluid. The cryptococcal titre was zero. The lungworm infection was treated successfully with abamectin and the cough resolved. Immunosuppression related to FIV infection may have predisposed this cat to sequential respiratory tract infections. PMID:10860150

  6. An initial examination of the potential role of T-cell immunity in protection against feline immunodeficiency virus (FIV) infection.

    PubMed

    Aranyos, Alek M; Roff, Shannon R; Pu, Ruiyu; Owen, Jennifer L; Coleman, James K; Yamamoto, Janet K

    2016-03-14

    The importance of vaccine-induced T-cell immunity in conferring protection with prototype and commercial FIV vaccines is still unclear. Current studies performed adoptive transfer of T cells from prototype FIV-vaccinated cats to partial-to-complete feline leukocyte antigen (FLA)-matched cats a day before either homologous FIVPet or heterologous-subtype pathogenic FIVFC1 challenge. Adoptive-transfer (A-T) conferred a protection rate of 87% (13 of 15, p < 0.001) against FIVPet using the FLA-matched T cells, whereas all 12 control cats were unprotected. Furthermore, A-T conferred protection rate of 50% (6 of 12, p<0.023) against FIVFC1 using FLA-matched T cells, whereas all 8 control cats were unprotected. Transfer of FLA-matched T and B cells demonstrated that T cells are needed to confer A-T protection. In addition, complete FLA-matching and addition of T-cell numbers > 13 × 10(6) cells were required for A-T protection against FIVFC1 strain, reported to be a highly pathogenic virus resistant to vaccine-induced neutralizing-antibodies. The addition of FLA-matched B cells alone was not protective. The poor quality of the anti-FIV T-cell immunity induced by the vaccine likely contributed to the lack of protection in an FLA-matched recipient against FIVFC1. The quality of the immune response was determined by the presence of high mRNA levels of cytolysin (perforin) and cytotoxins (granzymes A, B, and H) and T helper-1 cytokines (interferon-γ [IFNγ] and IL2). Increased cytokine, cytolysin and cytotoxin production was detected in the donors which conferred protection in A-T studies. In addition, the CD4(+) and CD8(+) T-cell proliferation and/or IFNγ responses to FIV p24 and reverse transcriptase increased with each year in cats receiving 1X-3X vaccine boosts over 4 years. These studies demonstrate that anti-FIV T-cell immunity induced by vaccination with a dual-subtype FIV vaccine is essential for prophylactic protection against AIDS lentiviruses such as FIV and

  7. Optimal Packaging of FIV Genomic RNA Depends upon a Conserved Long-range Interaction and a Palindromic Sequence within gag

    PubMed Central

    Rizvi, Tahir A.; Kenyon, Julia C.; Ali, Jahabar; Aktar, Suriya J.; Phillip, Pretty S.; Ghazawi, Akela; Mustafa, Farah; Lever, Andrew M.L.

    2010-01-01

    The feline immunodeficiency virus (FIV) is a lentivirus that is related to human immunodeficiency virus (HIV), causing a similar pathology in cats. It is a potential small animal model for AIDS and the FIV-based vectors are also being pursued for human gene therapy. Previous studies have mapped the FIV packaging signal (ψ) to two or more discontinuous regions within the 5′ 511 nt of the genomic RNA and structural analyses have determined its secondary structure. The 5′ and 3′ sequences within ψ region interact through extensive long-range interactions (LRIs), including a conserved heptanucleotide interaction between R/U5 and gag. Other secondary structural elements identified include a conserved 150 nt stem–loop (SL2) and a small palindromic stem–loop within gag open reading frame that might act as a viral dimerization initiation site. We have performed extensive mutational analysis of these sequences and structures and ascertained their importance in FIV packaging using a trans-complementation assay. Disrupting the conserved heptanucleotide LRI to prevent base pairing between R/U5 and gag reduced packaging by 2.8–5.5 fold. Restoration of pairing using an alternative, non-wild type (wt) LRI sequence restored RNA packaging and propagation to wt levels, suggesting that it is the structure of the LRI, rather than its sequence, that is important for FIV packaging. Disrupting the palindrome within gag reduced packaging by 1.5–3-fold, but substitution with a different palindromic sequence did not restore packaging completely, suggesting that the sequence of this region as well as its palindromic nature is important. Mutation of individual regions of SL2 did not have a pronounced effect on FIV packaging, suggesting that either it is the structure of SL2 as a whole that is necessary for optimal packaging, or that there is redundancy within this structure. The mutational analysis presented here has further validated the previously predicted RNA secondary

  8. Spontaneous programmed cell death (PCD) process of lymphocytes of FIV-infected cats: pharmacological modulation in vitro.

    PubMed

    Guiot, A L; Rigal, D; Chappuis, G

    1997-03-01

    We previously reported that unstimulated lymphocytes in culture from FIV-infected cats undergo spontaneous apoptosis in vitro as indicated by internucleosomal DNA fragmentation and hypodiploid DNA content of nuclei. Unlike what is reported in HIV-infected individuals, we observed that cell death of cat lymphocytes was inhibited by activation. Spontaneous apoptosis was reduced by the addition of cat serum, interleukins [interleukin (IL)1, Il2, IL6 and interferon-gamma (IFN gamma)] and after activation by phorbol ester [phorbol myristyl acetate (PMA)], superantigens [staphylococcal enterotoxin B (SEB), staphylococcal enterotoxin A (SEA)], and to a lesser extent by mitogens such as Concanavalin A and pokeweed mitogen, IN contrast, apoptosis of lymphocytes from FIV-infected, but not from control cats was increased in the presence of calcium ionophore (ionomycin). In this study, we studied the spontaneous programmed cell death (PCD)-inducing pathways, and the mechanisms of action of PMA, SEB and SEA. Spontaneous lymphocyte apoptosis of FIV-infected cats was inhibited by cycloheximide, ZnSO4 and N-acetyl-cystein. The preventive effect of SEB and SEA was inhibited by actinomycin, but not by inhibitors of kinases. Calyculin, an inhibitor of phosphatase, had no effect either on spontaneous apoptosis, or on the action of PMA, SEB and SEA. Ionomycin-induced apoptosis was found sensitive to PMA and cytokines. In FIV-infected cats, these data suggest that the mature lymphocytes appear programmed to die by apoptosis, unless rescued by specific agents, such as protein kinase C activators or growth factors, and that spontaneous PCD seems to be dependent of de nove protein synthesis (see effect of cycloheximide). The effects of PMA, SEB and SEA are probably mediated by de novo proteins which for PMA, undergo a phosphorylation involving serine-threonine and/or tyrosine groups. Our data suggest a clear difference between lymphocytes from FIV-infected cats and lymphocytes from HIV

  9. Deformation mechanisms in Be{sub 12}X compounds

    SciTech Connect

    Bruemmer, S.M.; Brimhall, J.L.; Charlot, L.A.; Sondhi, S.; Hoagland, R.G.; Hirth, J.P.

    1992-12-01

    Dislocation structures have been examined, and active slip systems identified, in Be{sub l2}Nb after compressive deformation at 20, 800, 900 1000 and 1200C. A large number of slip systems are active at 1200C, but these decrease significantly at temperatures below 1000C. Dislocation structures at low temperatures are limited to 1/2<101(101) partial dislocations either paired or creating isolated planar faults. Significant ductility is not observed until 1200C when a second type of partial dislocation, 1/2<100(011) is present. Dislocations observed in the body-centered tetragonal Be{sup 12}X compounds (where X can be Nb, Ta, Mo, V, Fe etc.) have been modelled atomistically using molecular dynamics. Simulations corroborate the stability of these dislocation systems and indicate that the stacking faults associated with these partial dislocations have very low fault energy.

  10. Serological survey of Toxoplasma gondii, Dirofilaria immitis, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) infections in pet cats in Bangkok and vicinities, Thailand.

    PubMed

    Sukhumavasi, Woraporn; Bellosa, Mary L; Lucio-Forster, Araceli; Liotta, Janice L; Lee, Alice C Y; Pornmingmas, Pitcha; Chungpivat, Sudchit; Mohammed, Hussni O; Lorentzen, Leif; Dubey, J P; Bowman, Dwight D

    2012-08-13

    The seroprevalence of Toxoplasma gondii, Dirofilaria immitis (heartworm), feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) infections was examined using serum or plasma samples from 746 pet cats collected between May and July 2009 from clinics and hospitals located in and around Bangkok, Thailand. The samples were tested for heartworm, FIV, and FeLV using a commercial ELISA. Of the 746 samples, 4.6% (34/746) were positive for heartworm antigen, 24.5% (183/746) had circulating FeLV antigen, and 20.1% (150/746) had antibodies against FIV. In addition, the first 348 submitted samples were tested for T. gondii antibodies using a modified agglutination test (MAT, cut off 1:25); 10.1% (35/348) were seropositive. Of the 348 cats sampled for all four pathogens, 11, 10, and 1 were positive for T. gondii antibodies and FIV antibodies, FeLV antigen, or D. immitis antigen, respectively. Of the 35 T. gondii-seropositive cats, 42.9% (15/35) were co-infected with at least one of the other three pathogens. The presence of antibodies to FIV was significantly associated with both age and gender, while FeLV antigen presence was only associated with age. In the case of FIV, males were twice as likely to be infected as females, and cats over 10 years of age were 13.5 times more likely to be infected than cats less than 1 year of age. FeLV antigen was more common in younger cats, with cats over 10 years of age being 10 times less likely to be FeLV positive than cats under 1 year of age. This is the first survey for these four pathogens affecting feline health in Thailand. PMID:22497870

  11. μSR study of charge neutrally doped RE1-2xCaxPrxBa2Cu3O7-δ (RE=Y,Nd)

    NASA Astrophysics Data System (ADS)

    Lundqvist, P.; Hartmann, O.; Karlsson, E.; Wäppling, R.; Hegedüs, Z.; Rapp, Ö.

    1996-02-01

    Pr substitution in the 123 superconductors lowers the critical temperature, Tc, drastically. Equal amounts of Ca and Pr were doped into the RE1-2xCaxPrxBa2Cu3O7-δ superconductors (RE=Y, x≤0.2 and Nd, x≤0.1) to isolate the linear term in this depression, often assigned to magnetic pair breaking. Uemura et al found a universal linear relation between Tc and the muon spin relaxation rate δ in high Tc cuprate superconductors with a saturation close to the maximum Tc. Our results indicate a faster decrease of Tc with decreasing δ in the saturaton regime than for Pr doping only and this rate is in turn faster than in oxygen doped 123, indicating multiple effects in the depression of Tc with Pr doping only.

  12. Serological survey of Toxoplasma gondii, Dirofilaria immitis, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) infections in pet cats in Bangkok and vicinities, Thailand

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The seroprevalence of Toxoplasma gondii, Dirofilaria immitis (heartworm), feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) infections was examined using serum or plasma samples from 746 pet cats collected between May and July 2009 from clinics and hospitals located in and around ...

  13. Improved health and survival of FIV-infected cats is associated with the presence of autoantibodies to the primary receptor, CD134

    PubMed Central

    Grant, Chris K.; Fink, Elizabeth A.; Sundstrom, Magnus; Torbett, Bruce E.; Elder, John H.

    2009-01-01

    We analyzed antibody responses in sera from feline immunodeficiency virus (FIV)-infected and uninfected cats. A strong antiviral response to the viral surface glycoprotein (SU) was noted in both natural and experimental infections. In addition, 143 of 226 FIV-infected animals (63%) also expressed antibodies to the primary binding receptor, CD134, whereas cats infected with other feline RNA viruses, including calicivirus, coronavirus, herpesvirus, and feline leukemia virus, did not. Both affinity-purified anti-CD134 and anti-SU antibodies blocked FIV infection ex vivo. FACS analyses revealed that the anti-CD134 antibodies bound to a cryptic epitope on the receptor that was only exposed when SU bound to CD134. Anti-CD134 binding caused displacement of SU from the surface of the cell and inhibition of infection. The presence of antibodies to CD134 correlated with lower virus loads and a better overall health status in FIV+ cats, whereas anti-SU antibodies were present independent of health status. The findings are consistent with a role for antireceptor antibodies in protection from virus spread and disease progression. PMID:19901342

  14. Viral Reservoirs in Lymph Nodes of FIV-Infected Progressor and Long-Term Non-Progressor Cats during the Asymptomatic Phase

    PubMed Central

    Eckstrand, C. D.; Hillman, C.; Smith, A. L.; Sparger, E. E.; Murphy, B. G.

    2016-01-01

    Background Examination of a cohort of cats experimentally infected with feline immunodeficiency virus (FIV) for 5.75 years revealed detectable proviral DNA in peripheral blood mononuclear cells (PBMCs) harvested during the asymptomatic phase, undetectable plasma viral RNA (FIV gag), and rarely detectable cell-associated viral RNA. Despite apparent viral latency in peripheral CD4+ T cells, circulating CD4+ T cell numbers progressively declined in progressor animals. The aim of this study was to explore this dichotomy of peripheral blood viral latency in the face of progressive immunopathology. The viral replication status, cellular immunophenotypes, and histopathologic features were compared between popliteal lymph nodes (PLNs) and peripheral blood. Also, we identified and further characterized one of the FIV-infected cats identified as a long-term non-progressor (LTNP). Results PLN-derived leukocytes from FIV-infected cats during the chronic asymptomatic phase demonstrated active viral gag transcription and FIV protein translation as determined by real-time RT-PCR, Western blot and in situ immunohistochemistry, whereas viral RNA in blood leukocytes was either undetectable or intermittently detectable and viral protein was not detected. Active transcription of viral RNA was detectable in PLN-derived CD4+ and CD21+ leukocytes. Replication competent provirus was reactivated ex vivo from PLN-derived leukocytes from three of four FIV-infected cats. Progressor cats showed a persistent and dramatically decreased proportion and absolute count of CD4+ T cells in blood, and a decreased proportion of CD4+ T cells in PLNs. A single long-term non-progressor (LTNP) cat persistently demonstrated an absolute peripheral blood CD4+ T cell count indistinguishable from uninfected animals, a lower proviral load in unfractionated blood and PLN leukocytes, and very low amounts of viral RNA in the PLN. Conclusion Collectively our data indicates that PLNs harbor important reservoirs of

  15. Seroprevalence of feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) in shelter cats on the island of Newfoundland, Canada.

    PubMed

    Munro, Hannah J; Berghuis, Lesley; Lang, Andrew S; Rogers, Laura; Whitney, Hugh

    2014-04-01

    Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses found within domestic and wild cat populations. These viruses cause severe illnesses that eventually lead to death. Housing cats communally for long periods of time makes shelters at high risk for virus transmission among cats. We tested 548 cats from 5 different sites across the island of Newfoundland for FIV and FeLV. The overall seroprevalence was 2.2% and 6.2% for FIV and FeLV, respectively. Two sites had significantly higher seroprevalence of FeLV infection than the other 3 sites. Analysis of sequences from the FeLV env gene (envelope gene) from 6 positive cats showed that 4 fell within the FeLV subtype-A, while 2 sequences were most closely related to FeLV subtype-B and endogenous feline leukemia virus (en FeLV). Varying seroprevalence and the variation in sequences at different sites demonstrate that some shelters are at greater risk of FeLV infections and recombination can occur at sites of high seroprevalence.

  16. Structure of FIV capsid C-terminal domain demonstrates lentiviral evasion of genetic fragility by coevolved substitutions.

    PubMed

    Khwaja, Aya; Galilee, Meytal; Marx, Ailie; Alian, Akram

    2016-01-01

    Viruses use a strategy of high mutational rates to adapt to environmental and therapeutic pressures, circumventing the deleterious effects of random single-point mutations by coevolved compensatory mutations, which restore protein fold, function or interactions damaged by initial ones. This mechanism has been identified as contributing to drug resistance in the HIV-1 Gag polyprotein and especially its capsid proteolytic product, which forms the viral capsid core and plays multifaceted roles in the viral life cycle. Here, we determined the X-ray crystal structure of C-terminal domain of the feline immunodeficiency virus (FIV) capsid and through interspecies analysis elucidate the structural basis of co-evolutionarily and spatially correlated substitutions in capsid sequences, which when otherwise uncoupled and individually substituted into HIV-1 capsid impair virion assembly and infectivity. The ability to circumvent the deleterious effects of single amino acid substitutions by cooperative secondary substitutions allows mutational flexibility that may afford viruses an important survival advantage. The potential of such interspecies structural analysis for preempting viral resistance by identifying such alternative but functionally equivalent patterns is discussed. PMID:27102180

  17. Structure of FIV capsid C-terminal domain demonstrates lentiviral evasion of genetic fragility by coevolved substitutions

    PubMed Central

    Khwaja, Aya; Galilee, Meytal; Marx, Ailie; Alian, Akram

    2016-01-01

    Viruses use a strategy of high mutational rates to adapt to environmental and therapeutic pressures, circumventing the deleterious effects of random single-point mutations by coevolved compensatory mutations, which restore protein fold, function or interactions damaged by initial ones. This mechanism has been identified as contributing to drug resistance in the HIV-1 Gag polyprotein and especially its capsid proteolytic product, which forms the viral capsid core and plays multifaceted roles in the viral life cycle. Here, we determined the X-ray crystal structure of C-terminal domain of the feline immunodeficiency virus (FIV) capsid and through interspecies analysis elucidate the structural basis of co-evolutionarily and spatially correlated substitutions in capsid sequences, which when otherwise uncoupled and individually substituted into HIV-1 capsid impair virion assembly and infectivity. The ability to circumvent the deleterious effects of single amino acid substitutions by cooperative secondary substitutions allows mutational flexibility that may afford viruses an important survival advantage. The potential of such interspecies structural analysis for preempting viral resistance by identifying such alternative but functionally equivalent patterns is discussed. PMID:27102180

  18. Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections in stray and pet cats (Felis catus) in northwest China: co-infections and risk factors.

    PubMed

    Cong, Wei; Meng, Qing-Feng; Blaga, Radu; Villena, Isabelle; Zhu, Xing-Quan; Qian, Ai-Dong

    2016-01-01

    This study was conducted to estimate the prevalence of Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections among stray and pet cats in Lanzhou, northwest China, and to identify the influence of age, gender, and regions on seropositivity. T. gondii antibodies were examined in cat sera by the modified agglutination test (MAT). The circulating antigens of D. immitis and FeLV and specific antibodies to FIV were examined using kits commercially available. The overall prevalence of T. gondii, FIV, FeLV, and D. immitis was 19.34, 9.12, 11.33, and 3.04 %, respectively. For the genetic characterization of T. gondii genotypes in cats, genomic DNA was extracted from the seropositive cats and the T. gondii B1 gene was amplified using a semi-nested PCR. DNA samples giving positive B1 amplification were then genotyped using multilocus PCR-RFLP. Two T. gondii genotypes (ToxoDB#9 and ToxoDB#1) were identified. Results of the multivariate logistic regression analysis showed that older cats are more likely to be seropositive than juveniles for T. gondii, FIV, FeLV, and D. immitis. This is the first report of T. gondii genotypes in cats in northwest China. Moreover, the present study is the first study of retrovirus and D. immitis seroprevalence in cats in China. The results revealed that T. gondii, FIV, and FeLV infections are common in stray and pet cats in northwest China.

  19. Could FIV zoonosis responsible of the breakdown of the pathocenosis which has reduced the European CCR5-Delta32 allele frequencies?

    PubMed Central

    Faure, Eric

    2008-01-01

    Background In Europe, the north-south downhill cline frequency of the chemokine receptor CCR5 allele with a 32-bp deletion (CCR5-Δ32) raises interesting questions for evolutionary biologists. We had suggested first that, in the past, the European colonizers, principally Romans, might have been instrumental of a progressively decrease of the frequencies southwards. Indeed, statistical analyses suggested strong negative correlations between the allele frequency and historical parameters including the colonization dates by Mediterranean civilisations. The gene flows from colonizers to native populations were extremely low but colonizers are responsible of the spread of several diseases suggesting that the dissemination of parasites in naive populations could have induced a breakdown rupture of the fragile pathocenosis changing the balance among diseases. The new equilibrium state has been reached through a negative selection of the null allele. Results Most of the human diseases are zoonoses and cat might have been instrumental in the decrease of the allele frequency, because its diffusion through Europe was a gradual process, due principally to Romans; and that several cat zoonoses could be transmitted to man. The possible implication of a feline lentivirus (FIV) which does not use CCR5 as co-receptor is discussed. This virus can infect primate cells in vitro and induces clinical signs in macaque. Moreover, most of the historical regions with null or low frequency of CCR5-Δ32 allele coincide with historical range of the wild felid species which harbor species-specific FIVs. Conclusion We proposed the hypothesis that the actual European CCR5 allelic frequencies are the result of a negative selection due to a disease spreading. A cat zoonosis, could be the most plausible hypothesis. Future studies could provide if CCR5 can play an antimicrobial role in FIV pathogenesis. Moreover, studies of ancient DNA could provide more evidences regarding the implications of

  20. Structural changes and superconducting properties of Gd1-2xPrxCaxBa2Cu3O7-δ HTSCs

    NASA Astrophysics Data System (ADS)

    Udomkan, N.; Winotai, P.; Suryanarayanan, R.; Charoenthai, N.

    2005-10-01

    We report on structural changes and the properties of Gd1-2xPrxCaxBa2Cu3O7-δ (0<=x<=0.3) high temperature superconductors which were prepared and characterized. The transition temperature (Tc) was found to decrease roughly linearly with respect to the Pr and Ca concentration x. 65Cu2+(3d9) and 63Cu2+(3d9) ions from impurity phase BaCuO2 give rise to X-band electron spin resonant (ESR) two-quartet absorption peaks centred at ~310 mT (g~2.020) which are superposed by the broad ESR peak of Gd3+(4f7) at g~2.000 in the undoped Gd123. Both sets of ESR peaks shift towards low fields as the temperature is lowered, which is due to the change in crystal field experienced by the ions. It should be noted here that even at 77 K there still is no magnetic ordering from Gd3+ ions. However, at x = 0.025 doping, a new six-peak hyperfine multiplet ESR signal arising from 141Pr4+ (4f1,S = 1/2,I = 5/2) appears at ~323 mT (g~2.029). Typical simulated ESR parameters of Gd3+ in Gd1-2xPrxCaxBa2Cu3O7-δ at x = 0.025, are gx = 2.4879, gy = 2.3921 and gz = 2.2590, Axx = 12.50, Ayy = 23.50, Azz = 32.00 G and the zero-field splitting parameter (D) of 66.0 G, respectively. This signal arises from some Pr ions entering the Gd site with a valence of four, thus lending support to the hole-filling and pair-breaking models.

  1. 27. A black & white photograph, 7 1/2" x 10" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. A black & white photograph, 7 1/2" x 10" on glossy paper. An aerial oblique of central Terre Haute. This view, taken looking north, shows the gas company building on the bottom margin, slightly right of center. On reverse, in black pencil, "Summer, 1965 Arnold-Damon Studio" and in blue ink cursive script, "Aerial Views 1974". Source: Indiana State University Archives. - John T. Beasley Building, 632 Cherry Street (between Sixth & Seventh Streets), Terre Haute, Vigo County, IN

  2. Adsorption of carbon dioxide on Al12X clusters studied by density functional theory: effect of charge and doping.

    PubMed

    Zhao, Jian-Ying; Zhang, Yu; Zhao, Feng-Qi; Ju, Xue-Hai

    2013-11-27

    The adsorption of a CO2 molecule on neutral and charged X-centered icosahedron Al12X(±z) clusters (X = Al, Be, Zn, Ni, Cu, B, P; z = 0, 1) was investigated by the density functional PW91 and PWC methods. Optimized configurations corresponding to physisorption and chemisorption of CO2 were identified. The adsorption energies, activation barriers, and binding energies involving both the physisorption (Al12X(±z)·CO2-I) and chemisorption (Al12X(±z)·CO2-II) for CO2 were determined. The chemisorption of a CO2 molecule on the Al12X clusters (X is a metallic doping element) requires relatively low activation barriers. The lowest barrier was found to be with the Al12Be cluster. For the Al12X(-) clusters, the barriers are all higher than those of the neutral analogues. For the Al12X(+) clusters, two corresponding configurations are linked by a low-energy barrier, and CO2 molecule chemisorption on the Al12Be(+) cluster has the lowest barrier. The adsorption energies are larger than the energy barriers, which facilitates the chemisorption. The results show that carbon dioxide adsorbed on the Al12X(±z) clusters can be tuned by controllable X doping and the total number of valence electrons and suggest the potential application of Al12X(±z) nanostructures for carbon dioxide capture and activation.

  3. The secondary structure of the 5' end of the FIV genome reveals a long-range interaction between R/U5 and gag sequences, and a large, stable stem-loop.

    PubMed

    Kenyon, Julia C; Ghazawi, Akela; Cheung, Winsome K S; Phillip, Pretty S; Rizvi, Tahir A; Lever, Andrew M L

    2008-12-01

    Feline immunodeficiency virus (FIV) is a lentivirus that infects cats and is related to human immunodeficiency virus (HIV). Although it is a common worldwide infection, and has potential uses as a human gene therapy vector and as a nonprimate model for HIV infection, little detail is known of the viral life cycle. Previous experiments have shown that its packaging signal includes two or more regions within the first 511 nucleotides of the genomic RNA. We have undertaken a secondary structural analysis of this RNA by minimal free-energy structural prediction, biochemical mapping, and phylogenetic analysis, and show that it contains five conserved stem-loops and a conserved long-range interaction between heptanucleotide sequences 5'-CCCUGUC-3' in R/U5 and 5'-GACAGGG-3' in gag. This long-range interaction is similar to that seen in primate lentiviruses where it is thought to be functionally important. Along with strains that infect domestic cats, this heptanucleotide interaction can also occur in species-specific FIV strains that infect pumas, lions, and Pallas' cats where the heptanucleotide sequences involved vary. We have analyzed spliced and genomic FIV RNAs and see little structural change or sequence conservation within single-stranded regions of the 5' UTR that are important for viral packaging, suggesting that FIV may employ a cotranslational packaging mechanism. PMID:18974279

  4. Rigidity Transitions in Ternary As_xGe_xSe_1-2x and As_xGe_xS_1-2x Glasses

    NASA Astrophysics Data System (ADS)

    Qu, Tao; Boolchand, Punit; Micoulaut, Matthieu

    2003-03-01

    These ternary glasses are of interest for elastic threshold studies because they do not display nanoscale phase separation^1 effects. MDSC measurements on As_xGe_xSe_1-2x glasses have shown^2 T_g(x) to increase monotonically with x, and the non-reversing heat flow, ΔHnr(x), to display a global minimum ˜ 0 in 0.09 < x < 0.14 range, or 2.27 < < 2.42. The thermally reversing window width in this ternary is large and resides below the Phillips-Thorpe value of rc = 2.4, features that were addressed in ref.1.We have now performed FT-Raman scattering as a function of x, and established compositional trend of corner-sharing mode frequency, ν_cs(x), of Ge(Se_1/2)4 tetrahedra. The results show evidence of a second order elastic threshold near r_c(1) = 2.27(1) and a first order one near r_c(2) = 2.42(1). At the latter, a jump in ν_cs of 0.5(1)cm-1 is observed. The elastic power-law in the intermediate phase yield a value p =0.90(5). Preliminary results on corresponding sulfide glasses have also been obtained. Supported by NSF grant DMR ^_01^_01808 1 P.Boolchand et al. Comptes Rendus ( in press). 2 Y.Wang et al. Europhysics Lett. 52,633(2000).

  5. Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections in stray and pet cats (Felis catus) in northwest China: co-infections and risk factors.

    PubMed

    Cong, Wei; Meng, Qing-Feng; Blaga, Radu; Villena, Isabelle; Zhu, Xing-Quan; Qian, Ai-Dong

    2016-01-01

    This study was conducted to estimate the prevalence of Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections among stray and pet cats in Lanzhou, northwest China, and to identify the influence of age, gender, and regions on seropositivity. T. gondii antibodies were examined in cat sera by the modified agglutination test (MAT). The circulating antigens of D. immitis and FeLV and specific antibodies to FIV were examined using kits commercially available. The overall prevalence of T. gondii, FIV, FeLV, and D. immitis was 19.34, 9.12, 11.33, and 3.04 %, respectively. For the genetic characterization of T. gondii genotypes in cats, genomic DNA was extracted from the seropositive cats and the T. gondii B1 gene was amplified using a semi-nested PCR. DNA samples giving positive B1 amplification were then genotyped using multilocus PCR-RFLP. Two T. gondii genotypes (ToxoDB#9 and ToxoDB#1) were identified. Results of the multivariate logistic regression analysis showed that older cats are more likely to be seropositive than juveniles for T. gondii, FIV, FeLV, and D. immitis. This is the first report of T. gondii genotypes in cats in northwest China. Moreover, the present study is the first study of retrovirus and D. immitis seroprevalence in cats in China. The results revealed that T. gondii, FIV, and FeLV infections are common in stray and pet cats in northwest China. PMID:26362646

  6. Magnetic hardening of CeFe12-xMox and the effect of nitrogenation

    SciTech Connect

    Zhou, C; Pinkerton, FE

    2014-01-15

    We report the magnetic hardening of CeFe12-xMox by melt spinning at surface wheel speeds between 10 m/s and 30 m/s. The synthesis range of CeFe12-xMox has been extended to CeFe11Mo, which uses the least amount of Mo substitution to stabilize the ThMn12-type structure. X-ray diffraction indicates that as-spun samples are multi-phased, typically consisting of a primary ThMn12-type phase with impurity phases of Fe-Mo alloy, Ce2Fe17 and CeFe2. However, nearly pure ThMn12-type phase can be obtained either by directly melt spinning at specific wheel speeds or by annealing the over-quenched ribbons at an optimum temperature. The magnetic moment of CeFe12-xMox is found to be affected not only by the number of Fe atoms but also by weakening of the Fe moment from Mo substitution. Nitriding is effective in enhancing the Curie temperature T-c and saturation magnetization 4 pi M-s. Tc was enhanced by at least 151 degrees C after nitrogenation for all compositions. The newly identified CeFe11Mo compound exhibits the best magnetic properties in the alloy series, having T-c = 370 degrees C and 4 pi M-s > 13.0 kG after nitriding and (BH)(max) = 0.3 MGOe after annealing. (C) 2013 Published by Elsevier B.V.

  7. Neutron-diffraction studies and bond valence sums of charge neutrally doped Nd1-2xCaxThxBa2Cu3O7-δ

    NASA Astrophysics Data System (ADS)

    Lundqvist, P.; Rapp, Ö.; Tellgren, R.; Bryntse, I.

    1997-08-01

    Equal amounts of Ca and Th have been doped into the Nd1-2xCaxThxBa2Cu3O7-δ superconductor with x=0, 0.015, 0.03, 0.05, and 0.10. This causes a fast and linear decrease of the superconducting transition temperature, Tc. A single orthorhombic phase was observed with x-ray diffraction except for weak additional lines for the x=0.10 sample, suggesting a solubility limit below x=0.10. Neutron-diffraction measurements were performed and bond valence sums (BVS's) were calculated. The results showed a small increase in the Cu2-O4 distance and a nearly constant Cu2 valence. The total hole density in the plane, V- as defined by Tallon, remains almost constant with doping in contrast to the decrease observed for Ca-Pr doping. Other results from the BVS calculations also indicate differences between Ca-Th and Ca-Pr doping in the NdBa2Cu3O7-δ compound.

  8. Implicit Large Eddy Simulation of a wingtip vortex at Rec =1.2x106

    NASA Astrophysics Data System (ADS)

    Lombard, Jean-Eloi; Moxey, Dave; Sherwin, Spencer; SherwinLab Team

    2015-11-01

    We present recent developments in numerical methods for performing a Large Eddy Simulation (LES) of the formation and evolution of a wingtip vortex. The development of these vortices in the near wake, in combination with the large Reynolds numbers present in these cases, make these types of test cases particularly challenging to investigate numerically. To demonstrate the method's viability, we present results from numerical simulations of flow over a NACA 0012 profile wingtip at Rec = 1.2 x106 and compare them against experimental data, which is to date the highest Reynolds number achieved for a LES that has been correlated with experiments for this test case. Our model correlates favorably with experiment, both for the characteristic jetting in the primary vortex and pressure distribution on the wing surface. The proposed method is of general interest for the modeling of transitioning vortex dominated flows over complex geometries. McLaren Racing/Royal Academy of Engineering Research Chair.

  9. Deformation mechanisms in Be[sub 12]X compounds. [X = Nb

    SciTech Connect

    Bruemmer, S.M.; Brimhall, J.L.; Charlot, L.A. ); Sondhi, S.; Hoagland, R.G.; Hirth, J.P. . Dept. of Mechanical and Materials Engineering)

    1992-12-01

    Dislocation structures have been examined, and active slip systems identified, in Be[sub l2]Nb after compressive deformation at 20, 800, 900 1000 and 1200C. A large number of slip systems are active at 1200C, but these decrease significantly at temperatures below 1000C. Dislocation structures at low temperatures are limited to 1/2<101(101) partial dislocations either paired or creating isolated planar faults. Significant ductility is not observed until 1200C when a second type of partial dislocation, 1/2<100(011) is present. Dislocations observed in the body-centered tetragonal Be[sup 12]X compounds (where X can be Nb, Ta, Mo, V, Fe etc.) have been modelled atomistically using molecular dynamics. Simulations corroborate the stability of these dislocation systems and indicate that the stacking faults associated with these partial dislocations have very low fault energy.

  10. Molecular Structure of Ge_xP_xS_1-2x Bulk Alloy Glasses

    NASA Astrophysics Data System (ADS)

    Vempati, U.; Boolchand, P.

    2004-03-01

    Rather complete Raman and MDSC results on the reversibility window and aging effects are now available on ternary Ge_xP_xSe_1-2x glasses. It is therefore of interest to understand in what manner replacing Se by S alters the reversibility window. We have synthesized titled glasses over the 0 < x < 0.24 range, and have examined them in Raman scattering and MDSC measurements. Unlike the case of Selenide glasses, in S-rich glasses S8 crowns segregate from the backbone altering the constraint counting. But as in the Se-deficient (x > 2/11) glasses, the S-deficient glasses are also found to partially nanoscale phase separate into P_4(S or Se)3 monomers. The reversibility window in the two chalcogenides will be compared and contrasted. *Supported by NSF grant DMR 01-01808

  11. Analysis of 12 X-chromosomal markers in the population of central Croatia.

    PubMed

    Crnjac, Josip; Ozretić, Petar; Merkaš, Siniša; Ratko, Martina; Lozančić, Mateja; Rožić, Sara; Špoljarić, Daniel; Korolija, Marina; Popović, Maja; Mršić, Gordan

    2016-07-01

    Investigator® Argus X-12 Kit is a commercially available set that allows simultaneous PCR amplification of 12 X-STR markers belonging to four linkage groups (LG). To assess the forensic efficiency of these markers for the population of central Croatia and consequent applicability in routine forensic casework, DNA from 200 blood samples of unrelated donors (100 female and 100 male) was amplified by Investigator® Argus X-12 Kit and analyzed by capillary electrophoresis. Statistical computations based on allele and haplotype frequencies for LG1 - LG4 were performed using Arlequin 3.5 software and on-line tool available at ChrX-STR.org. In female samples, all X-STR markers were in Hardy-Weinberg equilibrium (HWE). The most informative marker for central Croatia population was DXS10135 with polymorphism information content (PIC) 0.9296. The least polymorphic locus was DXS8378 (PIC=0.6363). Power of discrimination (PD) varied from 0.6968 to 0.9336 in male and from 0.8476 to 0.9916 in female samples. Combined PD exceeded 0.999999999 in both men and women. In male samples, linkage disequilibrium (LD) test revealed significant association (P=0.0000) of one marker pair in LG4 and two marker pairs in LG3. Portion of observed haplotypes in the number of possible haplotypes varied from 2.86% to 7.47% across all LGs. LG1 was the most informative with haplotype diversity (H) 0.9972. High PD of all analyzed markers exhibited for central Croatia population confirms suitability of Investigator® Argus X-12 for forensic pertinence. Moreover, results of this study will be included in establishing a national reference X-STR database based on 12 X-STR loci, which is necessary for the correct interpretation of the forensic casework results.

  12. Analysis of 12 X-chromosomal markers in the population of central Croatia.

    PubMed

    Crnjac, Josip; Ozretić, Petar; Merkaš, Siniša; Ratko, Martina; Lozančić, Mateja; Rožić, Sara; Špoljarić, Daniel; Korolija, Marina; Popović, Maja; Mršić, Gordan

    2016-07-01

    Investigator® Argus X-12 Kit is a commercially available set that allows simultaneous PCR amplification of 12 X-STR markers belonging to four linkage groups (LG). To assess the forensic efficiency of these markers for the population of central Croatia and consequent applicability in routine forensic casework, DNA from 200 blood samples of unrelated donors (100 female and 100 male) was amplified by Investigator® Argus X-12 Kit and analyzed by capillary electrophoresis. Statistical computations based on allele and haplotype frequencies for LG1 - LG4 were performed using Arlequin 3.5 software and on-line tool available at ChrX-STR.org. In female samples, all X-STR markers were in Hardy-Weinberg equilibrium (HWE). The most informative marker for central Croatia population was DXS10135 with polymorphism information content (PIC) 0.9296. The least polymorphic locus was DXS8378 (PIC=0.6363). Power of discrimination (PD) varied from 0.6968 to 0.9336 in male and from 0.8476 to 0.9916 in female samples. Combined PD exceeded 0.999999999 in both men and women. In male samples, linkage disequilibrium (LD) test revealed significant association (P=0.0000) of one marker pair in LG4 and two marker pairs in LG3. Portion of observed haplotypes in the number of possible haplotypes varied from 2.86% to 7.47% across all LGs. LG1 was the most informative with haplotype diversity (H) 0.9972. High PD of all analyzed markers exhibited for central Croatia population confirms suitability of Investigator® Argus X-12 for forensic pertinence. Moreover, results of this study will be included in establishing a national reference X-STR database based on 12 X-STR loci, which is necessary for the correct interpretation of the forensic casework results. PMID:27497338

  13. Rietveld refinement of the crystal structures of Rb2 XSi5O12 (X = Ni, Mn)

    PubMed Central

    Bell, Anthony M. T.; Henderson, C. Michael B.

    2016-01-01

    The synthetic leucite silicate framework mineral analogues Rb2 XSi5O12 {X = Ni [dirubidium nickel(II) penta­silicate] and Mn [dirubidium manganese(II) penta­silicate]} have been prepared by high-temperature solid-state synthesis. The results of Rietveld refinements, using X-ray powder diffraction data collected using Cu Kα X-rays, show that the title compounds crystallize in the space group Pbca and adopt the cation-ordered structure of Cs2CdSi5O12 and other leucites. The structures consist of tetra­hedral SiO4 and XO4 units sharing corners to form a partially substituted silicate framework. Extraframework Rb+ cations sit in channels in the framework. All atoms occupy the 8c general position for this space group. In these refined structures, silicon and X atoms are ordered onto separate tetra­hedrally coordinated sites (T-sites). However, the Ni displacement parameter and the Ni—O bond lengths suggest that for the X = Ni sample, there may actually be some T-site cation disorder. PMID:26958399

  14. The 12x32 Pop-Up Bolometer Array for the SHARC II Camera

    NASA Technical Reports Server (NTRS)

    Dowell, C. Darren; Groseth, Jeffrey E.; Phillips, Thomas G.; Allen, Christine A.; Babu, Sachidananda R.; Jhabvala, Murzy D.; Moseley, S. Harvey, Jr.; Voellmer, George M.

    2002-01-01

    SHARC II is a 350 micron facility camera for the Caltech Submillimeter Observatory (CSO) expected to come on-line in 2002. The key component of SHARC II is a 12x32 array of doped silicon 'pop-up' bolometers developed at NASA/Goddard and delivered to Caltech in March 2002. Each pixel is 1 mm x 1 mm, coated with a 400 Omega/square bismuth film, and located lambda/4 above a reflective backshort to maximize radiation absorption. The pixels cover the focal plane with greater than 95% filling factor. Each doped thermistor occupies nearly the full area of the pixel to minimize 1/f noise. We report some results from the first cold measurements of this array. The bolometers were located inside a dark cover, and 4x32 pixels were read simultaneously. In the best 25% of winter nights on Mauna Kea, SHARC II is expected to have an NEFD at 350 microns of 1 Jy s(sup 1/2) or better.

  15. A study of the properties of SrFe12-xCoxO19 nanoparticles

    NASA Astrophysics Data System (ADS)

    Mousavi Ghahfarokhi, S. E.; Ranjbar, F.; Zargar Shoushtari, M.

    2014-01-01

    In this paper, the nanoparticles of SrFe12-xCoxO19 (x=0-2) were synthesized via the sol-gel technique. The XRD results showed that all samples with x≤0.5 are single-phase. It seems that the Fe3+ ions are substituted by Co2+ ions in the crystallography sites of the SrFe12O19 structure, but for the x>0.5 cases, the phase of CoFe2O4 is materialized in the samples. The DC electrical resistivity decreases with the increase of cobalt content up to level of x=0.5, but it increases on further addition of cobalt. We found that the dielectric constant and the dielectric loss for samples with x=1 and 1.2 into the pure sample (SrFe12O19), decrease as the Co2+ content increases. The variation of AC conductivity (σac) with frequency ranging from 500 Hz to 200 KHz shows that electrical conductivity in these ferrites is mainly due to the electron hopping mechanism.

  16. Rietveld refinement of the crystal structures of Rb2 XSi5O12 (X = Ni, Mn).

    PubMed

    Bell, Anthony M T; Henderson, C Michael B

    2016-02-01

    The synthetic leucite silicate framework mineral analogues Rb2 XSi5O12 {X = Ni [dirubidium nickel(II) penta-silicate] and Mn [dirubidium manganese(II) penta-silicate]} have been prepared by high-temperature solid-state synthesis. The results of Rietveld refinements, using X-ray powder diffraction data collected using Cu Kα X-rays, show that the title compounds crystallize in the space group Pbca and adopt the cation-ordered structure of Cs2CdSi5O12 and other leucites. The structures consist of tetra-hedral SiO4 and XO4 units sharing corners to form a partially substituted silicate framework. Extraframework Rb(+) cations sit in channels in the framework. All atoms occupy the 8c general position for this space group. In these refined structures, silicon and X atoms are ordered onto separate tetra-hedrally coordinated sites (T-sites). However, the Ni displacement parameter and the Ni-O bond lengths suggest that for the X = Ni sample, there may actually be some T-site cation disorder. PMID:26958399

  17. The thermally reversing window in ternary GexPxS1-2x glasses

    NASA Astrophysics Data System (ADS)

    Vempati, U.; Boolchand, P.

    2004-11-01

    GexPxS1-2x glasses in the compositional range 0.05 \\le x \\le 0.19 have been synthesized and examined in temperature modulated differential scanning calorimetry (MDSC) and Raman scattering experiments. Trends in the non-reversing enthalpy ΔHnr(x) near Tg show the term to almost vanish in the 0.090(5)0.135. In analogy to previous results on chalcogenide glasses, we identify compositions at x<0.09 to be elastically floppy, those in the 0.0900.135 to be stressed rigid. MDSC results also show that the ΔHnr term ages in the stressed-rigid and floppy phases but not in the intermediate phase. The intermediate phase is viewed to be a self-organized phase of a disordered network. It consists of at least four isostatically rigid local structures: corner-sharing GeS4, edge-sharing GeS2, pyramidal P(S1/2)3 and quasi-tetrahedral S = P(S1/2)3 units for which evidence comes from Raman scattering. The latter method also shows the existence of P4S7 and P4S10 molecules in the glasses segregated from the backbone. These aspects of structure contribute to an intermediate phase that is significantly narrower in width than in the corresponding selenide glasses.

  18. RHIC 12x150A current lead temperature controller: design and implementation

    SciTech Connect

    Mi, C.; Seberg, S.; Ganetis, Hamdi, K.; Louie, W.; Heppner, G.; Jamilkowski, J.; Bruno, D.; DiLieto, A.; Sirio, C.; Tuozzolo, J.; Sandberg, J.; Unger, K.

    2011-03-28

    There are 60 12 x 150A current leads distributed in six RHIC service buildings; each lead delivers power supply current from room temperature to cryogenic temperature in RHIC. Due to the humid environment, condensation occurs frequently and ice forms quickly during operation, especially during an extensive storage period. These conditions generate warnings and alarms to which personnel must respond and establish temporary solutions to keep the machine operating. In here, we designed a temperature control system to avoid such situations. This paper discusses its design, implementation, and some results. There are six service buildings in the RHIC complex; each building has two valve boxes that transfer room-temperature current cables from the power supplies into superconducting leads, and then transport them into the RHIC tunnel. In there, the transition between the room-temperature lead into superconducting lead is critical and essential; smooth running during the physics store is crucial for the machine's continuing operation. One of the problems that often occurred previously was the icing of these current leads that could result in a potential leakage current onto ground, thereby preventing a continuous supply of physics store. Fig. 1 illustrates a typical example on a power lead. Among the modifications of the design of the valve box, we list below the new requirements for designing the temperature controller to prevent icing occurring: (1) Remotely control, monitor, and record each current lead's temperature in real time. Prevent icing or overheating of a power lead. (2) Include a temperature alarm for the high/low level threshold. In this paper we discuss the design, implementation, upgrades to, and operation of this new system.

  19. Synthesis and electrochemical characterization of pillared layered Li1-2xCaxCoO2

    NASA Astrophysics Data System (ADS)

    Yang, W. S.; Li, X. M.; Yang, L.; Evans, D. G.; Duan, X.

    2006-05-01

    The pillared layered Li1-2xCaxCoO2 has been obtained for the first time by a molten salt ion exchange reaction. The X-ray diffraction data of the materials show that they are single phase and retain the layered α-NaFeO2 type structure. The electrochemical testing of Li1-2xCaxCoO2 cells with an upper cutoff potential of 4.5 and 4.7 V (vs. Li+/Li) show that the specific capacity of the oxides have been increased, respectively, to 175 and 211 mAh g-1, and retain better charge discharge cycling performance. The XRD data shows these improvements are attributed to the pillaring role of Ca2+ which helps to suppress unwanted phase transition.

  20. Nanostructured H(3+x)PW(12-x)NbxO40 (x = 0-3) Keggin heteropolyacid catalysts.

    PubMed

    Choi, Jung Ho; Park, Dong Ryul; Park, Sunyoung; Song, In Kyu

    2011-09-01

    Nanostructured H(3+x)PW(12-x)NbxO40 (x = 0, 1, 2, 3) Keggin heteropolyacid (HPA) catalysts were investigated by scanning tunneling microscopy (STM) and tunneling spectroscopy to probe their redox property and oxidation catalysis. STM image showed that the HPAs formed two-dimensional well-ordered monolayer arrays on graphite surface. In tunneling spectra of the HPAs deposited on graphite, they exhibited a distinctive current-voltage behavior referred to as negative differential resistance (NDR). NDR peak voltage measured atop HPA molecule was then correlated with reduction potential and absorption edge energy determined by electrochemical method and UV-visible spectroscopy, respectively. It was revealed that NDR peak voltage of the HPAs appeared at less negative voltage with increasing reduction potential and with decreasing absorption edge energy. In order to correlate NDR peak voltage of H(3+x)PW(12-x)NbxO40 Keggin HPAs with oxidation catalysis, oxidative dehydrogenation of isobutyraldehyde to methacrolein was carried out as a model reaction. NDR peak voltage of the HPAs appeared at less negative voltage with increasing yield for methacrolein. PMID:22097499

  1. Structure and optical properties of [In1-2xSnxZnx]GaO3(ZnO)m

    NASA Astrophysics Data System (ADS)

    Eichhorn, Simon; Mader, Werner

    2016-01-01

    Compounds of [In1-2xSnxZnx]GaO3(ZnO)1 (x≤0.22) and [In1-2xSnxZnx]GaO3(ZnO)2 (x≤0.42) were prepared by solid state processing proving a substantial solid solution of Sn in the layered compounds InGaO3(ZnO)m (m=1, 2). Single crystal X-ray diffraction of the compounds reveals two In3+ ions to be substituted by one Sn4+ and one Zn2+ at the octahedral layer preserving the average charge of +3 at these sites. The substitution does not lead to an ordering of the ions but proves for the first time that the octahedral site can be occupied by different ions while all characteristics of the layered structures remain unchanged. Consequences of indium substitution are (i) decrease of the a axis compared to InGaO3(ZnO)m according to smaller ionic radii of Sn4+ and Zn2+ compared to In3+ and (ii) shift of the optical band gap to higher energies shown by UV-vis measurements.

  2. Energy transfer processes in Ca3Tb2-xEuxSi3O12 (x = 0-2)

    NASA Astrophysics Data System (ADS)

    Carrasco, I.; Bartosiewicz, K.; Nikl, M.; Piccinelli, F.; Bettinelli, M.

    2015-10-01

    The luminescent properties of Tb3+ and Eu3+ have been studied in several silicates having a silico-carnotite-type structure. Fast energy migration among Tb3+ ions has been found in Ca3Tb2Si3O12 and Ca3Tb2-xEuxSi3O12 (x = 0-0.1). In the case of Ca3Tb2-xEuxSi3O12, Tb3+-Eu3+ energy transfer is observed upon excitation in the UV bands of Tb3+. The transfer gives rise to strong emission from Eu3+ in the red spectral region at 612 nm. The efficiency of the transfer at room temperature in Ca3Tb1.9Eu0.1Si3O12 has been evaluated. The temperature evolution of the luminescent properties of Ca3Tb2Si3O12 and Ca3Tb1.9Eu0.1Si3O12 has been studied at temperatures ranging from 8 to 330 K.

  3. Structural and magnetic properties of Vanadium Doped M- Type Barium Hexaferrite (BaFe12-xVxO19)

    NASA Astrophysics Data System (ADS)

    Awadallah, Ahmad; Mahmood, Sami H.; Maswadeh, Yazan; Bsoul, Ibrahim; Aloqaily, Aynour

    2015-10-01

    Precursor powders of barium hexaferrite doped with vanadium, BaFe12-xVxO19 with (x = 0.1, 0.2, 0.3, 0.4, 0.5), were prepared using the ball milling technique and then sintered at different temperatures for 2 h. The structural properties of the prepared samples were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), while the magnetic properties were examined by the vibrating sample magnetometry (VSM). XRD and SEM studies of the samples sintered at 1100° C indicated the presence of Ba3V2O8 and α-Fe2O3 non-magnetic oxide phases in addition to BaM hexaferrite phase. The fractions of the nonmagnetic oxide phases were found to increase with increasing x, and sintering the samples at temperatures higher than 1100° C was found to reduce the amounts of these non-magnetic phases only slightly. However, the addition of barium in excess of the stoichiometric ratio was found to remove the α-Fe2O3 oxide, and improve the saturation magnetization of the samples significantly. In addition, washing these samples with HCl was found to improve the saturation magnetization further. The effect of sintering the samples at higher temperatures was also found to reduce the coercivity due to growth of the particle size. However, the coercivity of all samples remained high enough for potential permanent magnet and magnetic recording applications.

  4. Low energy structures of lithium-ion battery materials Li(MnxNixCo1-2x)O2 revealed by first-principles calculations

    NASA Astrophysics Data System (ADS)

    Shang, ShunLi; Wang, Yi; Wang, William Y.; Fang, Huazhi; Liu, Zi-Kui

    2013-07-01

    A long-standing issue regarding the low energy structures for the partially disordered cathode materials Li(MnxNixCo1-2x)O2 has been probed by first-principles calculations. It is found that the transitional metals Mn, Ni, and Co in Li(MnxNixCo1-2x)O2 follow the maximum entropy probability distribution (MEPD), instead of the random distribution, according to the distributions of the minimal partial radial distribution functions and the correlation functions. Here, the MEPD is proposed to understand the low energy structures of the partially disordered lithium-ion battery materials.

  5. PR-PR: cross-platform laboratory automation system.

    PubMed

    Linshiz, Gregory; Stawski, Nina; Goyal, Garima; Bi, Changhao; Poust, Sean; Sharma, Monica; Mutalik, Vivek; Keasling, Jay D; Hillson, Nathan J

    2014-08-15

    To enable protocol standardization, sharing, and efficient implementation across laboratory automation platforms, we have further developed the PR-PR open-source high-level biology-friendly robot programming language as a cross-platform laboratory automation system. Beyond liquid-handling robotics, PR-PR now supports microfluidic and microscopy platforms, as well as protocol translation into human languages, such as English. While the same set of basic PR-PR commands and features are available for each supported platform, the underlying optimization and translation modules vary from platform to platform. Here, we describe these further developments to PR-PR, and demonstrate the experimental implementation and validation of PR-PR protocols for combinatorial modified Golden Gate DNA assembly across liquid-handling robotic, microfluidic, and manual platforms. To further test PR-PR cross-platform performance, we then implement and assess PR-PR protocols for Kunkel DNA mutagenesis and hierarchical Gibson DNA assembly for microfluidic and manual platforms. PMID:25126893

  6. PR-PR: Cross-Platform Laboratory Automation System

    SciTech Connect

    Linshiz, G; Stawski, N; Goyal, G; Bi, CH; Poust, S; Sharma, M; Mutalik, V; Keasling, JD; Hillson, NJ

    2014-08-01

    To enable protocol standardization, sharing, and efficient implementation across laboratory automation platforms, we have further developed the PR-PR open-source high-level biology-friendly robot programming language as a cross-platform laboratory automation system. Beyond liquid-handling robotics, PR-PR now supports microfluidic and microscopy platforms, as well as protocol translation into human languages, such as English. While the same set of basic PR-PR commands and features are available for each supported platform, the underlying optimization and translation modules vary from platform to platform. Here, we describe these further developments to PR-PR, and demonstrate the experimental implementation and validation of PR-PR protocols for combinatorial modified Golden Gate DNA assembly across liquid-handling robotic, microfluidic, and manual platforms. To further test PR-PR cross-platform performance, we then implement and assess PR-PR protocols for Kunkel DNA mutagenesis and hierarchical Gibson DNA assembly for microfluidic and manual platforms.

  7. PR-PR: cross-platform laboratory automation system.

    PubMed

    Linshiz, Gregory; Stawski, Nina; Goyal, Garima; Bi, Changhao; Poust, Sean; Sharma, Monica; Mutalik, Vivek; Keasling, Jay D; Hillson, Nathan J

    2014-08-15

    To enable protocol standardization, sharing, and efficient implementation across laboratory automation platforms, we have further developed the PR-PR open-source high-level biology-friendly robot programming language as a cross-platform laboratory automation system. Beyond liquid-handling robotics, PR-PR now supports microfluidic and microscopy platforms, as well as protocol translation into human languages, such as English. While the same set of basic PR-PR commands and features are available for each supported platform, the underlying optimization and translation modules vary from platform to platform. Here, we describe these further developments to PR-PR, and demonstrate the experimental implementation and validation of PR-PR protocols for combinatorial modified Golden Gate DNA assembly across liquid-handling robotic, microfluidic, and manual platforms. To further test PR-PR cross-platform performance, we then implement and assess PR-PR protocols for Kunkel DNA mutagenesis and hierarchical Gibson DNA assembly for microfluidic and manual platforms.

  8. On the oxidation of the three-dimensional aromatics [B(12)X(12)](2-) (X=F, Cl, Br, I).

    PubMed

    Boeré, René T; Derendorf, Janis; Jenne, Carsten; Kacprzak, Sylwia; Kessler, Mathias; Riebau, Rainer; Riedel, Sebastian; Roemmele, Tracey L; Rühle, Monika; Scherer, Harald; Vent-Schmidt, Thomas; Warneke, Jonas; Weber, Stefan

    2014-04-01

    The perhalogenated closo-dodecaborate dianions [B12 X12 ](2-) (X=H, F, Cl, Br, I) are three-dimensional counterparts to the two-dimensional aromatics C6 X6 (X=H, F, Cl, Br, I). Whereas oxidation of the parent compounds [B12 H12 ](2-) and benzene does not lead to isolable radicals, the perhalogenated analogues can be oxidized by chemical or electrochemical methods to give stable radicals. The chemical oxidation of the closo-dodecaborate dianions [B12 X12 ](2-) with the strong oxidizer AsF5 in liquid sulfur dioxide (lSO2 ) yielded the corresponding radical anions [B12 X12 ](⋅-) (X=F, Cl, Br). The presence of radical ions was proven by EPR and UV/Vis spectroscopy and supported by quantum chemical calculations. Use of an excess amount of the oxidizing agent allowed the synthesis of the neutral perhalogenated hypercloso-boranes B12 X12 (X=Cl, Br). These compounds were characterized by single-crystal X-ray diffraction of dark blue B12 Cl12 and [Na(SO2 )6 ][B12 Br12 ]⋅B12 Br12 . Sublimation of the crude reaction products that contained B12 X12 (X=Cl, Br) resulted in pure dark blue B12 Cl12 or decomposition to red B9 Br9 , respectively. The energetics of the oxidation processes in the gas phase were calculated by DFT methods at the PBE0/def2-TZVPP level of theory. They revealed the trend of increasing ionization potentials of the [B12 X12 ](2-) dianions by going from fluorine to bromine as halogen substituent. The oxidation of all [B12 X12 ](2-) dianions was also studied in the gas phase by mass spectrometry in an ion trap. The electrochemical oxidation of the closo-dodecaborate dianions [B12 X12 ](2-) (X=F, Cl, Br, I) by cyclic and Osteryoung square-wave voltammetry in liquid sulfur dioxide or acetonitrile showed very good agreement with quantum chemical calculations in the gas phase. For [B12 X12 ](2-) (X=F, Cl, Br) the first and second oxidation processes are detected. Whereas the first process is quasi-reversible (with oxidation potentials in the range between +1

  9. Fabrication and magnetic property of BaSm(x)Fe(12-x)O19 (x < or = 0.4) nanofibers.

    PubMed

    Xian-Feng, Meng; Li-Ju, Guo

    2012-03-01

    BaSm(x)Fe(12-x)O19 (x < or = 0.4) ferrite nanofibers were prepared by sol-gel method from starting reagents of metal salts and citric acid. These nanofibers were characterized by TG-DTA, FTIR, SEM, XRD and VSM. These results show that the BaSm(x)Fe(12-x)O19 (x < or = 0.4) ferrite nanofibers were obtained subsequently from calcination at 750 degrees C for 1 h. The BaSm(x)Fe(12-x)O19 (x < or = 0.4) microstructure and magnetic property are mainly influenced by chemical composition and heat-treatment temperature. The grain sizes of BaSm0.3Fe11.7O19 ferrite nanofibers are in a nanoscale from 40 nm to 62 nm corresponding to the calcination temperature from 750 degrees C to 1050 derees C. The saturation magnetization of BaSm(x)Fe(12-x)O19 ferrite nanofiber calcined at 950 degrees C for 1 h initially decreases with the Sm content from 0 to 0.3 and then increases with a further Sm content, while the coercivity exhibits a continuous increase from 348 kA x m(-1) (x = 0) to 427 kA x m(-1) (x = 0.4). The differences of magnetic properties are attributed to lattice distortion and enhancement for the anisotropy energy. PMID:22755131

  10. Photoluminescence of Vanadate Garnet Ca2NaMg(2-x)V3O12:xEu3+ Phosphors Synthesized by Solution Combustion Method.

    PubMed

    Kim, H; Kim, J; Lim, S; Park, K

    2016-02-01

    In this study, a series of nano-sized Ca2NaMg(2-x)V3O12:xEu3+ (0.06 < or = x < or = 0.18) red phosphors is synthesized by solution combustion method. The microstructure and photoluminescence properties of the Ca2NaMg(2-x)V3O12:xEu3+ phosphors are studied in accordance with the Eu3+ content. Annealed Ca2NaMg(2-x)V3O12:xEu3+ phosphors form a single phase with the cubic garnet structure and Ia3d space group. The emission from (VO4)3- in the Ca2NaMg(2-x)V3O12:xEu3+ phosphors is almost completely quenched due to the efficient energy transfer from the (VO4)3- to the Eu3+ ions. The emission intensity increases sharply with the increased Eu3+ content, reaching a maximum value at x = 0.15, and then decreases with further Eu3+ content. Ca2NaMg1.85V3O12:0.15Eu3+ shows great potential as a red phosphor for white light-emitting diodes. PMID:27433680

  11. Development of two multiplex PCR systems for the analysis of 12 X-chromosomal STR loci in a northwestern Italian population sample.

    PubMed

    Robino, C; Giolitti, A; Gino, S; Torre, C

    2006-09-01

    Two multiplex polymerase chain reaction systems for the automated profiling of 12 X-chromosomal short tandem repeat (STR) markers were developed. Multiplex A consisted of DXS6789, DXS6809, GATA172D05, DXS101, DXS8378, and DXS8377. Multiplex B consisted of DXS7132, DXS6800, DXS6801, DXS7424, HPRTB, and DXS10011. The set of amplified X-STRs was designed to include groups of closely linked markers (DXS101-DXS7424 and DXS6789-DXS6801-DXS6809) to generate highly informative haplotypes for kinship testing. A population genetics study of the 12 X-STRs was conducted in a northwestern Italian population sample (n=160, 80 women and 80 men). A diallelic pattern at locus DXS6789 was observed in one man. PMID:16862443

  12. Development of two multiplex PCR systems for the analysis of 12 X-chromosomal STR loci in a northwestern Italian population sample.

    PubMed

    Robino, C; Giolitti, A; Gino, S; Torre, C

    2006-09-01

    Two multiplex polymerase chain reaction systems for the automated profiling of 12 X-chromosomal short tandem repeat (STR) markers were developed. Multiplex A consisted of DXS6789, DXS6809, GATA172D05, DXS101, DXS8378, and DXS8377. Multiplex B consisted of DXS7132, DXS6800, DXS6801, DXS7424, HPRTB, and DXS10011. The set of amplified X-STRs was designed to include groups of closely linked markers (DXS101-DXS7424 and DXS6789-DXS6801-DXS6809) to generate highly informative haplotypes for kinship testing. A population genetics study of the 12 X-STRs was conducted in a northwestern Italian population sample (n=160, 80 women and 80 men). A diallelic pattern at locus DXS6789 was observed in one man.

  13. Structure and dielectric properties of solid solutions Bi7Ti4 + x W x Ta1-2 x O21 ( x = 0-0.5)

    NASA Astrophysics Data System (ADS)

    Zubkov, S. V.; Vlasenko, V. G.; Shuvaeva, V. A.; Shevtsova, S. I.

    2016-01-01

    A number of solid solutions Bi7Ti4 + x W x Ta1-2 x O21 ( x = 0-0.5) have been synthesized from oxides by solid-phase reaction. The crystal structure, the electrophysical characteristics, and the microstructure of the prepared ceramic samples have been studied. According to X-ray powder diffraction, all the compounds are single-phase with the structure of mixed-layer Aurivillius phases ( m = 2.5) with the orthorhombic crystal lattice (space group I2 cm, Z = 2). Temperature dependences of the relative permittivity ɛ( T) of the compound have been measured, from which it has been found that the Curie temperature T C of perovskite-like oxides Bi7Ti4 + x W x Ta1-2 x O21 ( x = 0-0.5) decreases linearly as substitution parameter x decreases. The activation energies of charge carriers have been found in different temperature ranges.

  14. Crystal structure and magnetic properties of the BaFe12-xInxO19 (x=0.1-1.2) solid solutions

    NASA Astrophysics Data System (ADS)

    Trukhanov, S. V.; Trukhanov, A. V.; Turchenko, V. A.; Kostishin, V. G.; Panina, L. V.; Kazakevich, I. S.; Balagurov, A. M.

    2016-11-01

    The investigations of the crystal and magnetic structure by powder neutron diffractometry as well as the magnetic properties by vibration sample magnetometry for the BaFe12-xInxO19 (x=0.1-1.2) solid solutions have been performed at different temperatures and magnetic fields. The atomic coordinates and lattice parameters have been Rietveld refined. The Invar effect has been observed in low temperature range (from 150 K to 10 K). It was explained by the thermal oscillation anharmonicity of atoms. The increase of microstress value with decreasing temperature has been defined from Rietveld refinement. The Curie temperature and change of total magnetic moment per formula unit have been defined for all the compositions of the barium hexaferrites BaFe12-xInxO19 (x=0.1-1.2) solid solutions. The magnetic structure model is proposed. The most likely reasons and the mechanism of magnetic structure formation are discussed.

  15. The first-principles study of Al12X (X = Sc-Zn) clusters and their adsorption of H, O and N

    NASA Astrophysics Data System (ADS)

    Zhang, Jingjing; Sun, Jun; Liu, Yanqi; Li, Jiao; Liang, Xiaogang; Duan, Haiming

    2016-07-01

    Started from the four types 13-atom high-symmetric (Ih, Oh, D5h, D3h) close-packed structures and by replacing a 3d transition metal atom in the nonequivalent position, the geometrical and electronic properties of the doped Al12X (X = Sc-Zn) clusters are systematically studied by using the density-functional theory. Close-packed (icosahedral-like) structures are found to be favorable for the ground state geometries and the degenerate isomers of Al12X (X = Sc, Ti, V, Ni, Cu) clusters. The magnetic moments of the doped Al12X (X = Cr, Mn and Fe) are substantially increased as compared with that of the pure Al13, which are mainly derived from the strong spin splitting of the d electrons of the doped atoms. For the absorption of H, O and N on the close-packed Al12X clusters, it is found that H atom tend to occupy the top or bridge site instead of the hollow site, but the adsorption sites of O and N atom are more complex. O and N are always adsorbed around the doped atom of the doped cluster with the doped atom on the surface and the adsorption energies of O and N on the doped clusters are all enhanced as compared with that on pure Al13, but it is quite different for the adsorption of H, which implies that the influences of the d electrons of the doped atoms on O and N are stronger than that on H. All doped clusters exhibit the same selective sequence of adsorption: O > N > H.

  16. Préface

    NASA Astrophysics Data System (ADS)

    Chardonnet, Christian; Millot, Guy

    2006-10-01

    COLOQ, réunion nationale biennale initiée en 1988 par la communauté française des lasers, de l'optique non linéaire et de l'optique quantique atteint sa neuvième édition. Depuis sa création, les objectifs poursuivis sont les suivants : - réunir la communauté française des lasers, de l'optique non linéaire et de l'optique quantique, en dépassant les clivages fondamental/appliqué, recherche publique/industrielle, - faire le point sur les avancées récentes, - permettre aux jeunes chercheurs de se rencontrer, de s'exprimer et de s'aguerrir au plan national. Le but est que tout thésard du domaine de l'optique puisse participer à COLOQ une fois durant sa thèse, présenter son travail et de se confronter à la communauté de l'optique. COLOQ9 s'est tenu, pour sa 9e édition, sur le campus universitaire de Dijon, du 7 au 9 septembre 2005. Il a été une grande réussite : nombre de participants (255) et de présentations scientifiques record (148 affiches), forte représentation des industriels (15) et participation d'environ 200 lycéens aux conférences grand public. Le nombre plus élevé que prévu d'affiches a rendu un peu serrée leur présentation : une attention particulière sera portée à cet aspect lors des prochaines éditions. Ces journées ont été consacrées à des conférences invitées données par des scientifiques de haut niveau et à des présentations sous forme d'affiches. Une plage de temps importante a été réservée pour des discussions autour des affiches. À proximité immédiate de la salle de conférence, l'exposition de matériels spécialisés pour les lasers, l'optique et l'optoélectronique a été une occasion pour les jeunes participants de découvrir et contacter les industriels et les autres grands acteurs de l'optique. L'année 2005 ayant été l'année mondiale de la physique, COLOQ9 a retenu comme thème central ”1905-2005 : à propos d'Einstein". Plusieurs grandes conférences ont été dédiées à ce th

  17. Pseudotetragonal structure of Li(2+x)Ce(x)(3+)Ce(12-x)(4+)F(50): the first mixed valence cerium fluoride.

    PubMed

    Renaudin, Guillaume; Dieudonné, Belto; Avignant, Daniel; Mapemba, Elise; El-Ghozzi, Malika; Fleutot, Solène; Martinez, Hervé; Cerný, Radovan; Dubois, Marc

    2010-01-18

    The crystal structure of the new Li(5.5)Ce(12)F(50) compound has been fully characterized by single-crystal and synchrotron powder X-ray diffraction. An accurate pseudotetragonal structure was described in the monoclinic P2(1) space group with 68 independent crystallographic sites. The Li(5.5)Ce(12)F(50) composition belongs to the Li(2+x)Ce(x)(3+)Ce(12-x)(4+)F(50) solid solution. Its structure consists of an opened fluorine framework where a channel network allows the intercalation of relatively mobile lithium cations, inducing the formation of the mixed-valence cerium (the intercalation of Li(+) leads to the reduction of a part of Ce(4+) to Ce(3+)). One part of the lithium ions, necessary for the electroneutrality of the tetravalent equivalent cerium fluoride (Li(2)Ce(12)F(50) composition), is in a locked fluorine polyhedron. Only the supplementary x amount of lithium is able to be exchanged in Li(2+x)Ce(x)(3+)Ce(12-x)(4+)F(50). The structure of Li(2+x)Ce(x)(3+)Ce(12-x)(4+)F(50) is a rearrangement, due to lithium intercalation, of the base CeF(4) structure. Bond valence calculation on Ce sites, Ce coordination polyhedra volumes, and a calculated Ce cationic radius give the indication of a partial long-range ordering of trivalent and tetravalent cerium cations in specific slabs of the structure. (7)Li NMR spectroscopy and XPS analyses have confirmed all of the structure details.

  18. Mesoporous Li4Ti5O(12-x)/C submicrospheres with comprehensively improved electrochemical performances for high-power lithium-ion batteries.

    PubMed

    Lin, Chunfu; Lai, Man On; Zhou, Henghui; Lu, Li

    2014-12-01

    To comprehensively improve the performance of Li4Ti5O12 (LTO), a synergistic method combining compositing, crystal structure modification and hierarchical particle structuring is employed in this work. Monodispersed/multidispersed mesoporous Li4Ti5O12-x/C submicrospheres were fabricated using monodispersed/multidispersed TiO2 submicrospheres, lithium hydroxide and sucrose as precursors. The Li4Ti5O12-x/C submicrospheres have a well-crystallized spinel structure, no blockages of Li(+) ion transport pathways, 2.69-3.03% O(2-) vacancy contents (vs. all 32e sites in the spinel structure), and 12.9-14.6% Ti(3+) ion contents (vs. all titanium ions). Thus, the electronic conductivity and Li(+) ion diffusion coefficient of particles can be significantly improved, and the working potential is 4.4-4.7 mV lower than that of LTO. Furthermore, these submicrospheres contain 1.06-1.44 wt% carbon as carbon coatings (2-3 nm in thickness) and carbon nanoparticles (∼20 nm in size), resulting in smaller primary particle sizes (<100 nm), large specific surface areas (12-15 m(2) g(-1)), proper pore sizes (∼4 nm) and enhanced electrical conduction between particles. In addition, the submicrospherical morphology allows large tap densities (1.41-1.71 g cm(-3)). As a result of this desirable structure, these mesoporous Li4Ti5O12-x/C submicrospheres exhibit comprehensively improved electrochemical performances. The optimized sample, with an ideally graded sphere-size distribution ranging from 100 nm to 600 nm, shows the largest tap density of 1.71 g cm(-3), high first cycle Coulombic efficiency of 95.0% and 4.5 mV lower working potential. At 10 C, its capacity is as high as 119 mA h g(-1) with capacity retention of 95.9% over 100 cycles. PMID:25322079

  19. Dielectric, Electromechanical and Ferroelectric Properties of (Na0.5Bi0.5)(NdxTi1-2xNbx)O3 Relaxor Ceramics

    NASA Astrophysics Data System (ADS)

    Mahboob, S.; Prasad, G.; Kumar, G. S.

    Polycrystalline (Na0.5Bi0.5)(NdxTi1-2xNbx)O3 ceramics with perovskite structure were prepared through the solid state sintering route. The prepared samples were studied for their dielectric, electromechanical and ferroelectric properties. Dielectric measurements showed relaxor behavior. From electromechanical studies, a relatively high electro-mechanical coupling factor, kt (in the range 0.69-0.73) depending upon composition was observed. Among the samples studied, x = 0.0125 exhibited a higher value of remanant polarization (~ 0.50 μC/cm2 at coercive field (Ec = 6.30 kV/cm)).

  20. Magnetic Properties of Zn1-xMnxO and Zn1-2xMnxLixO Nano Materials

    NASA Astrophysics Data System (ADS)

    Zou, You-ming; Tong, Wei; Qu, Zhe

    2011-06-01

    Zn1-xMnxO nanorods and Zn1-2xMnxLixO nano-particles were synthesized by solvothermal method at 160 °C. X-ray diffraction and Raman results showed that Mn ions were well incorporated into the ZnO matrix. No magnetic hysteresis were found in the magnetization curves. The hyperfine structures were observed in electron spin resonance spectra, indicating no ferromagnetic interaction between substituted Mn ions. The co-doping of Li can only change the morphology not the magnetic properties.

  1. Characterization and optimized electrochemical performances of LiFe(1-2x)ZrxPO4/C nanocomposites as cathode materials for lithium-ion batteries.

    PubMed

    Fan, Qi; Tai, Wei; Liu, Xue Wen; Tang, Yue Feng; Chen, Yan Feng

    2012-05-01

    A series of nanocomposite LiFe(1-2x)ZrxPO4/C (x = 0.01,0.02, 0.03, 0.04, 0.06) were prepared by carbon thermal reduction method. With this strategy, the Li3PO4 impurity phase can be obviously reduced in the Zr-doped samples and the electrochemical performance is obviously improved by Zr doping compared with the undoped one. The best electrochemical performances were observed in LiFe(0.92)Zr(0.04)PO4/C as well as good cycle stability.

  2. Préface

    NASA Astrophysics Data System (ADS)

    Mazière, D.

    2002-04-01

    Faisant suite aux deux précédents colloques "Matériaux pour les machines thermiques" et "Matériaux pour le nucléaire" , le colloque 2001 de l'INSTN intitulé "Matériaux pour les énergies propres" s'est focalisé sur les problèmes de matériaux encore à résoudre dans ce secteur industriel. Le colloque de métallurgie est traditionnellement organisé par des ense ignants du DEA Métallurgie et Matériaux et un comité scientifique choisi chaq ue année en liaison avec le thème traité. Les étudiants de ce DEA, qui est hab ilité entre Paris XI, Paris VI, l'Ecole des Mines de Paris, l'Ecole Centrale de Pari s et l'INSTN, sont invités à participer à ce colloque et aux débats scientifiques qui s'y déroulent. Des conférences invitées à caractère péda gogique permettent d'introduire les différents thèmes abordés qui sont ensuite développés dans des présentations plus novatrices. Cette manifestation a pour ambition de favoriser la rencontre de scientifiques d'horizons divers venant de milieux académiques ou industriels entre eux et avec les étudiants et thésards. Cette 44e édition, dont les comptes rendus sont publiés ici, a fait le point sur les problèmes de matériaux rencontrés lors de la production, du stockage et de la conversion des énergies dites propres en englobant lesprogrès constants des industriels de l'automobile. Ce colloque a réuni, du 26 au 28 juin 2001, 63 participants provenant d'universités ou grandes écoles (18), du CEA (17), du CNRS (10) et de l'industrie ou de centres de recherche associés. L'ensemble des problèmes de matériaux de ce secteur ont été examinés au cours des six sessions ci-dessous : dépollution des gaz d'échappement ; combustion catalytique en production thermique ; nouvelles batteries ; piles à combustibles ; production et stockage d'hydrogène ; production et stockage d'énergie solaire. Vingt huit communications dont vingt deux orales ont illustré les dével oppements en cours. Dix

  3. Préface

    NASA Astrophysics Data System (ADS)

    Aspect, Alain

    2004-11-01

    COLOQ est une conférence regroupant, tous les deux ans, la communauté scientifique et industrielle nationale travaillant dans les domaines des lasers, de l'optique non-linéaire et de l'optique quantique. Elle s'est tenue pour sa huitième édition à Toulouse, du 3 au 5 septembre 2004, sur le campus de I'INSA. Comme il est de tradition tous les quatre ans, COLOQ était couplé avec Horizons de l'optique, avec en particulier une journée commune dont le programme avait été préparé en concertation par les deux comités scientifiques. Depuis sa création, COLOQ a pour but de favoriser les rencontres entre les chercheurs des différents laboratoires nationaux publics ou privés travaillant sur les lasers et l'optique quantique au sens large. C'est un moyen privilégié de resserrer les liens de cette communauté et d'y intégrer les jeunes chercheurs. Ces derniers y trouvent l'occasion de se connaître, de se faire connaître, de découvrir la communauté à laquelle ils appartiennent et d'élargir leurs connaissances des thèmes qui la structurent. La participation de 230 chercheurs et d'une vingtaine d'exposants de matériels spécialisés dans les lasers et l'optoélectronique témoigne de la vitalité de COLOQ et de son audience dans les laboratoires et chez les industriels de l'optique. Le programme de COLOQ 8 comportait d'une vingtaine de conférences générales données par des chercheurs de renom international, et des séances de communications par affiches, occasions privilégiées de rencontres et d'échanges. Les exposés ont porté sur des sujets particulièrement actifs au niveau national et international, avec un accent sur des thèmes importants pour la région toulousaine : contrôle cohérent, optique et nanosciences, optique et astronomie, sans oublier la traditionnelle rubrique phénomènes fondamentaux, éclectique pour ne pas dire hétéroclite, mais si représentative d'une des ambitions de COLOQ qui est d'offrir à ses participants une

  4. Spin-glass like behavior in a new ternary uranium cobalt aluminide, U 3Co 4+ xAl 12- x with x=0.55(2)

    NASA Astrophysics Data System (ADS)

    Tougait, O.; Noël, H.; Troc, R.

    2004-06-01

    The new compound U 3Co 4+ xAl 12- x, where x=0.55(2), was prepared by arc-melting of the elemental components, followed by a prolonged annealing at elevated temperature. Scanning electron microscopy-energy-dispersive spectroscopy and powder X-ray diffraction were used to determine the deviation from the ideal stoichiometry. A small homogeneity range, that extends around the composition U 3Co 4+ xAl 12- x with 0.4(1) ⩽ x⩽0.7(1), could be detected. Single-crystal diffraction experiments revealed that U 3Co 4.55Al 11.45 crystallizes with the Gd 3Ru 4Al 12 type-structure, (space group P6 3/ mmc, Z=2) in a cell of dimensions at room temperature, a=8.6518(2) Å, c=9.2620(2) Å. The crystal structure can be viewed as an intergrowth of two distinct layers of Co and Al atoms, and U, Al and mixed Al/Co atoms that pile up along the hexagonal axis. The results of the DC magnetization suggest the occurrence of a spin glass state at low temperature ( Tf=8 K). The origin of freezing of the magnetic moments may arise from a topological frustration due to the location of the U atoms on the apexes of a distorted Kagomé lattice.

  5. Fabrication of SrFe12- x Ni x O19 nanoparticles and investigation on their structural, magnetic and dielectric properties

    NASA Astrophysics Data System (ADS)

    Mousavi Ghahfarokhi, S. E.; Hosseini, S.; Zargar Shoushtari, M.

    2015-08-01

    SrFe12- x Ni x O19 nanoparticles ( x = 0-1) were synthesized by a combustion sol-gel method. Their structure, dielectric and magnetic properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), an LCR metry, and vibrating sample magnetometry (VSM).The results reveal that all samples of Ni doped compounds (SrFe12- x Ni x O19) with x < 0.2 are single phase. It appears that the Fe3+ ions are substituted by Ni2+ ions on the crystallographic sites of the SrFe12O19 structure; however, for x ≥ 0.2, the secondary Ni phase ferrite (NiFe2O3) appears, which reduces the saturation magnetization and coercivity. In addition, Ni doping reduces the dielectric constant, dielectric loss, and alternating current (ac) electrical conductivity of the samples. The variation in ac conductivity ( σ ac) with frequency shows that the electrical conductivity in these ferrites is mainly attributed to the electron hopping mechanism.Therefore; all the single-phase Ni doped samples are suitable for use in magnetic recording media and microwave devices.

  6. Ba(Zn(1-2x)MnxCux)2As2: A Bulk Form Diluted Ferromagnetic Semiconductor with Mn and Cu Codoping at Zn Sites.

    PubMed

    Man, Huiyuan; Guo, Shengli; Sui, Yu; Guo, Yang; Chen, Bin; Wang, Hangdong; Ding, Cui; Ning, F L

    2015-10-23

    We report the synthesis and characterization of a bulk form diluted magnetic semiconductor Ba(Zn(1-2x)MnxCux)2As2 (0.025 ≤ x ≤ 0.2) with the crystal structure identical to that of "122" family iron based superconductors and the antiferromagnet BaMn2As2. No ferromagnetic order occurs with (Zn, Mn) or (Zn, Cu) substitution in the parent compound BaZn2As2. Only when Zn is substituted by both Mn and Cu simultaneously, can the system undergo a ferromagnetic transition below TC ~ 70 K, followed by a magnetic glassy transition at Tf  ~ 35 K. AC susceptibility measurements for Ba(Zn0.75Mn0.125Cu0.125)2As2 reveal that Tf strongly depends on the applied frequency with [formula in text] and a DC magnetic field dependence of [formula in text], demonstrating that a spin glass transition takes place at Tf. As large as -53% negative magnetoresistance has been observed in Ba(Zn(1-2x)MnxCux)2As2, enabling its possible application in memory devices.

  7. Magnetism in Zn1-2xMnxCoxO (x = 0.00, 0.01, 0.02, and 0.03) Nanostructures

    NASA Astrophysics Data System (ADS)

    Rajkumar, N.; Ramachandran, K.

    2011-07-01

    In this work, we report the structural, optical, and magnetic properties of Zn1-2xMnxCoxO (x = 0.00, 0.01, 0.02, and 0.03) nanostructures which were synthesized by seed based chemical method under ambient conditions. The X-Ray diffraction analysis reveals the wurtzite structure of ZnO nanostructures with no secondary crystalline phase due to doping. The morphologies of samples were examined using scanning electron microscopy and transmission electron microscopy, which indicate the formation of ZnO nanorods (diameter˜150 nm and length˜10 μm) for undoped sample and the growth of nanorods were affected with the increase of dopant concentration. The elemental compositions were analyzed by energy dispersive spectroscopy and X-Ray photoelectron spectroscopy (XPS), which infers the presence of oxygen deficiency due to rapid growth of nanostructures. From XPS analysis, the presence of Co and Mn in divalent form was confirmed and no metallic clusters in the semiconducting matrix. The absorption measurement shows that the optical band gaps of doped samples were slightly shifted towards higher energy side from undoped one due to the morphological change. The magnetic studies by vibrating sample magnetometer shows the absence of ferromagnetism down to 2 K for Zn1-2xMnxCoxO (x = 0.00, 0.01, 0.02, and 0.03) nanostructures.

  8. Ba(Zn1-2xMnxCux)2As2: A Bulk Form Diluted Ferromagnetic Semiconductor with Mn and Cu Codoping at Zn Sites

    NASA Astrophysics Data System (ADS)

    Man, Huiyuan; Guo, Shengli; Sui, Yu; Guo, Yang; Chen, Bin; Wang, Hangdong; Ding, Cui; Ning, F. L.

    2015-10-01

    We report the synthesis and characterization of a bulk form diluted magnetic semiconductor Ba(Zn1-2xMnxCux)2As2 with the crystal structure identical to that of “122” family iron based superconductors and the antiferromagnet BaMn2As2. No ferromagnetic order occurs with (Zn, Mn) or (Zn, Cu) substitution in the parent compound BaZn2As2. Only when Zn is substituted by both Mn and Cu simultaneously, can the system undergo a ferromagnetic transition below TC ~ 70 K, followed by a magnetic glassy transition at Tf  ~ 35 K. AC susceptibility measurements for Ba(Zn0.75Mn0.125Cu0.125)2As2 reveal that Tf strongly depends on the applied frequency with and a DC magnetic field dependence of , demonstrating that a spin glass transition takes place at Tf. As large as -53% negative magnetoresistance has been observed in Ba(Zn1-2xMnxCux)2As2, enabling its possible application in memory devices.

  9. Préface

    NASA Astrophysics Data System (ADS)

    Ouerdane, Youcef; Laporte, Pierre

    2005-06-01

    L'objectif de la série de colloques UVX est de réunir, au rythme d'une fois tous les deux ans, les scientifiques et industriels travaillant dans le domaine du développement des sources de photon de grande énergie (UV, VUV, et X) et de leurs applications. En particulier cette manifestation est l'occasion de faire se rencontrer une communauté très pluridisciplinaire (physique, chimie, biologie, sciences de l'univers) liée à des domaines en forte évolution technologique (lasers et rayonnement synchrotron notamment). Le colloque UVX 2004 s'est tenu au Palais des Congrès de Saint-Étienne (42000) du 7 au 11 juin 2004. La période écoulée depuis l'édition précédente (Oléron 2002) a été particulièrement active dans tous les domaines concernés : grands projets de sources, méthodes de diagnostic au sens large. Une nouvelle fois on constate que le bref et l'ultra-bref ont une place privilégiée, qu'il s'agisse du travail sur les accélérateurs ou sur les lasers qui, bien sûr, dans la course aux temps courts remportent la palme avec la présence de spécialistes du domaine attoseconde. La communauté représentée a la chance d'être en prise directe avec de très grands projets en phase active de réalisation comme le Laser Megajoule (LMJ), la source SOLEIL, et un projet d'ampleur plus modeste mais remarquable dans son domaine : la source LASERIX d'Orsay/Palaiseau. On pourra citer aussi le projet Arc en Ciel qui, lui, est encore au stade de sa définition. - SOLEIL, source de nouvelle génération de rayonnement synchrotron (plateau de Saclay) est dans une phase active de réalisation : achèvement de l'infrastructure en 2005 et injection du 1o faisceau dans l'anneau de stockage prévu également en 2005. Cette source devrait être la meilleure au monde dans le domaine VUV/X mous, tout en restant très polyvalente (brillance, accordabilité, structure temporelle, polarisation) et complémentaire de l'ESRF. Au final on disposera de 21 lignes de lumi

  10. ESO PR Highlights in 2006

    NASA Astrophysics Data System (ADS)

    2007-01-01

    Last year proved to be another exceptional year for the European organisation for ground-based astronomy. ESO should begin the New Year with two new member states: Spain (PR 05/06) and the Czech Republic (PR 52/06). ESO PR Highlights 2006 2006 was a year of renovation and revolution in the world of planets. A new Earth-like exoplanet has been discovered (PR 03/06) using a network of telescopes from all over the world (including the Danish 1.54-m one at ESO La Silla). It is not the only child of this fruitful year: thanks to the combined use of ESO's Very Large Telescope (VLT) and La Silla instruments, a surprising system of twin giant exoplanets was found (PR 29/06), and a trio of Neptune-like planets hosted by a nearby star were identified (PR 18/06). These results open new perspectives on the search for habitable zones and on the understanding of the mechanism of planet formation. The VISIR instrument on the VLT has been providing unique information to answer this last question, by supplying a high resolution view of a planet-forming disc (PR 36/06). There are not only new members in the planets' register: during the General Assembly of the International Astronomical Union held in Prague (Czech Republic), it was decided that Pluto is not a planet anymore but a 'dwarf planet'. Whatever its status, Pluto still has a satellite, Charon, whose radius and density have been measured more accurately by observing a rare occultation from different sites, including Cerro Paranal (PR 02/06). The scientific community dedicated 2006 to the great physicist James Clerk Maxwell (it was the 175th anniversary of the birth): without his electromagnetic theory of light, none of the astonishing discoveries of modern physics could have been achieved. Nowadays we can look at distant galaxies in great detail: the GIRAFFE spectrograph on the VLT revealed that galaxies 6 billion years ago had the same amount of dark matter relative to stars than nowadays (PR 10/06), while SINFONI gave an

  11. Préface

    NASA Astrophysics Data System (ADS)

    Rozelot, J.-P.; Bijaoui, A.

    2002-03-01

    Ce livre reprend pour l'essentiel des cours qui ont été dispensées lors de deux Écoles thématiques réalisées avec le concours du CNRS. La première fait partie du cycle des Écoles d'Astrophysique Solaire d'Oléron (F), dont le succès est grandissant dans la communauté concernée. La seconde s'est tenue spécifiquement à La Grande Motte près de Montpellier (F). L'objectif de ces Écoles, qui se sont tenues à une année d'intervalle, était de donner aux chercheurs concernés, qu'ils soient du secteur des Sciences de l'Univers ou de celui des Sciences pour l'Ingénieur, une formation aux nouvelles méthodes d'analyses de données, afin de leur faire bien comprendre l'intérêt de ces nouveaux outils pour la résolution de leurs problèmes scientifiques. En effet, les chercheurs disposent d'une quantité de plus en plus grande d'informations obtenues grâce aux très nombreux observatoires spatiaux et au sol. Pour l'analyse de ces données, des logiciels complexes ont été mis au point et distribués dans les laboratoires. Grâce au réseau, chacun peut extraire d'une banque de données les signaux ou les images observées, les réduire avec des programmes disposant d'une documentation élaborée et obtenir des résultats scientifiques pertinents. Mais les chercheurs sont souvent limités dans leurs connaissances pour aborder les problèmes d'analyse des données, et ils sont perplexes devant le choix de l'algorithme a utiliser. L'analyse des données est une discipline vaste, ayant justement pour tâche de permettre l'extraction des informations pertinentes des observations. La formation à ces méthodes contemporaines, formation qui a été proposée et est relatée dans ce livre, permet à chacun de mieux concevoir sa stratégie d'analyse pour pouvoir ainsi choisir les programmes de manière judicieuse. Cet ouvrage, novateur, se veut d'offrir de nouvelles idées et d'ouvrir de nouvelles voies. Il est divisé en trois grandes parties qui permettent au

  12. Préface

    NASA Astrophysics Data System (ADS)

    Jörgen Stevefelt, Henri Bachau Et

    2003-06-01

    UVX 2002, sixième édition du “Colloque sur les Sources Cohérentes et Incohérentes UV, VUV, et X : Applications et Développements Récents" s'est tenu du 11 au 14 juin 2002 au Centre CAES du CNRS “La Vieille, Perrotine", à Saint-Pierre d'Oléron. Le colloque a réunni une centaine de chercheurs et d'industriels et a permis de faire le point sur la production, la caractérisation et l'utilisation de rayonnement dans un domaine spectral s'étendant de l'ultraviolet aux rayons X. Les participants ont pu assister a trente conférences et une table ronde autour des problèmes locaux de pollution, une cinquantaine d'affiches ont été présentées au travers de deux sessions. Une douzaine d'industriels ont exposé leurs produits durant les séances d'affiches.Conformément aux éditions précédentes, les domaines couverts par le colloque UVX 2002 sont très variés et il est impossible de les résumer en quelques lignes. Parmi les activités en développement rapide on notera les lasers femtosecondes dont les applications se multiplient dans les laboratoires (propriétés des molécules, agrégats et solides), dans l'industrie (usinage, ablation...) et en médecine. L'absence de thermalisation ou de diffusion thermique ouvre aussi des perspectives pour la réalisation de films minces par ablation laser, un domaine où les lasers excimères sont traditionnellement utilisés, avec des applications importantes dans le secteur des télécommunications. Dans le domaine de l'extrème UV, des progrès significatifs ont été réalisés par plusieurs groupes dans la gamme de longueur d'onde de 5 à 20 nm, ouvrant ainsi la voie au développement industriel de la lithographie EUV. On note les progrès dans la réalisation des sources UV et X (laser X, génération d'harmoniques, laser a électrons libres) et la nécessité de développer des optiques adaptées. Une perspective intéressante, ouverte par la génération d'harmoniques, est la production d

  13. Préface

    NASA Astrophysics Data System (ADS)

    Paulus, Werner; Meinnel, Jean

    2003-02-01

    de vue européen, si les sources de l'ILL et d'ISIS peuvent encore être considérées comme des leaders au point de vue mondial, il est évidemment souhaitable que la nouvelle source neutronique à spallation (European Spallation Source : ESS) soit rapidement réalisée. Aujourd'hui ce projet est bien avancé, cette source devrait dépasser le flux des sources actuelles par près de deux ordres de grandeur et ainsi de maintenir au meilleur niveau les compétences Européennes. Il est évident qu'une utilisation efficace et intelligente des sources existantes, mais aussi de celles de la nouvelle génération, implique une certaine infrastructure nationale tant au niveau de la conception, de la réalisation que du fonctionnement des différents spectromètres. Ceci implique un très fort engagement des universités dans les différents projets de recherche. Le devoir des universités qui en résulte est donc d'intégrer l'utilisation des “grands instruments" dans leur programme d'enseignement. Dans ce sens, nous souhaitons que ce cours, entièrement rédigé en français, contribue à la fois à aider les chercheurs “non spécialistes” à accéder plus facilement au domaine neutronique, mais aussi à servir de base aux enseignants pour l'organisation et la préparation de leurs cours.Nous tenons à remercier tous les collègues qui ont accepté de rédiger de façon détaillée les cours qu'ils avaient présentés oralement dans la grande salle du VVF de Trégastel, ainsi que toutes les personnes qui ont contribué à la réussite du séjour ou à la réalisation de ce fascicule. Nous gardons un excellent souvenir de l'atmosphère de l'École qui a eu lieu à Trégastel, en plein centre de la côte de granite rose en Bretagne, en mai 2001 et était jumelée avec les Journées de la diffusion neutronique, elles aussi organisées sous l'égide de la SFN.Nous souhaitons que la lecture de cet ouvrage soit utile à un maximum de chercheurs.

  14. Glycerol electrocatalytic oxidation on Pt(1-2x)RuxSnxOy/Ti electrodes prepared by the polymeric precursor method

    NASA Astrophysics Data System (ADS)

    do Valle, Wanderson Ferraz; Junco, Gustavo Garcia; Profeti, Demetrius; Olivi, Paulo; Profeti, Luciene P. R.

    2015-11-01

    This work investigated the behavior of glycerol oxidation on Pt(1-2x)RuxSnxOy/Ti electrodes. Thermal decomposition of polymeric precursors furnished the catalysts at different compositions. Energy dispersive X-ray, scanning electronic microscopy, and cyclic voltammetry aided catalysts characterization. The electrodes presented high surface area and compositions similar to the nominal ones. Cyclic voltammetry and chronoamperometry showed that the glycerol oxidation current densities of mixed electrodes were higher than that of platinum alone at low potential values. The onset potential of glycerol oxidation shifted toward less positive values, showing that these materials facilitated oxidation as compared with platinum. The Pt0.8Ru0.1Sn0.10Oy/Ti electrode presented the highest electroactivity.

  15. Excess conductivity in Y 1-2xCa xTb xBa 2Cu 3O 7-δ

    NASA Astrophysics Data System (ADS)

    Han, Shun-Hui; Lundqvist, P.; Rapp, Ö.

    1997-08-01

    Superconducting fluctuations have been studied in zero magnetic field in sintered samples of Y 1-2xCa xTb xBa 2Cu 3O 7-δ by electrical resistivity measurements for x=0, 0.025, and 0.05. The excess conductivity Δσ was analysed as a function of reduced temperature ɛ=ln(T/T c) in the range -5 < ln ɛ < -1.5. With decreasing temperature, characteristic cross-overs were found in all samples from 2D to 3D behavior, and at a lower temperature to a critical regime, with characteristic exponents in Δσ∝ ɛα of α1=-1, α2=-0.5 and α3 ≈ -0.4 respectively.

  16. A Structural Study of the Perovskite Series CaTi 1-2 xFe xNb xO 3

    NASA Astrophysics Data System (ADS)

    Chakhmouradian, Anton R.; Mitchell, Roger H.

    1998-07-01

    An X-ray powder diffraction study of the series CaTi1-2xFexNbxO3is presented. The series comprises orthorhombic perovskites (Pbnm,a≈b≈√2ap,c≈2ap,Z=4) in the range 0≤x≤0.3, and monoclinic perovskites (P21/n,a≈b≈√2ap,c≈2ap,β≠90°,Z=4) in the range 0.4≤x≤0.5. The structure of the orthorhombic members is derived from the cubic aristotype by octahedral rotationa-a-c+. The structural distortion in the monoclinic members involves octahedral rotation and short-range cation ordering at theB-site (4cand 4d). In the series CaTi1-2xFexNbxO3, the unit-cell parameters and degree of octahedral rotation increase withx. The [111]ptilt angle increases from 16.1° in CaTiO3to 17.6-18.9° in CaFe1/2Nb1/2O3(for the NbO6and FeO6octahedra, respectively). In contrast to previous studies, here the diffraction pattern of the end-member CaFe1/2Nb1/2O3is interpreted to exhibit splitting of thehklandh0llines indicative of a monoclinic derivative of the CaTiO3-type structure.

  17. High ZT in p-type (PbTe)1-2x(PbSe)x(PbS)x thermoelectric materials.

    PubMed

    Korkosz, Rachel J; Chasapis, Thomas C; Lo, Shih-han; Doak, Jeff W; Kim, Yoon Jun; Wu, Chun-I; Hatzikraniotis, Euripidis; Hogan, Timothy P; Seidman, David N; Wolverton, Chris; Dravid, Vinayak P; Kanatzidis, Mercouri G

    2014-02-26

    Lead chalcogenide thermoelectric systems have been shown to reach record high figure of merit values via modification of the band structure to increase the power factor or via nanostructuring to reduce the thermal conductivity. Recently, (PbTe)1-x(PbSe)x was reported to reach high power factors via a delayed onset of interband crossing. Conversely, the (PbTe)1-x(PbS)x was reported to achieve low thermal conductivities arising from extensive nanostructuring. Here we report the thermoelectric properties of the pseudoternary 2% Na-doped (PbTe)1-2x(PbSe)x(PbS)x system. The (PbTe)1-2x(PbSe)x(PbS)x system is an excellent platform to study phase competition between entropically driven atomic mixing (solid solution behavior) and enthalpy-driven phase separation. We observe that the thermoelectric properties of the PbTe-PbSe-PbS 2% Na doped are superior to those of 2% Na-doped PbTe-PbSe and PbTe-PbS, respectively, achieving a ZT ≈2.0 at 800 K. The material exhibits an increased the power factor by virtue of valence band modification combined with a very reduced lattice thermal conductivity deriving from alloy scattering and point defects. The presence of sulfide ions in the rock-salt structure alters the band structure and creates a plateau in the electrical conductivity and thermopower from 600 to 800 K giving a power factor of 27 μW/cmK(2). The very low total thermal conductivity values of 1.1 W/m·K of the x = 0.07 composition is accounted for essentially by phonon scattering from solid solution defects rather than the assistance of endotaxial nanostructures.

  18. Préface

    NASA Astrophysics Data System (ADS)

    Moncorgé, R.

    2006-12-01

    Cette nouvelle édition du Colloque UVX avait pour objectifs de : - réunir les chercheurs et les industriels intéressés par les applications et les développements les plus récents obtenus sur les sources UV, VUV et X, cohérentes ou incohérentes, et les optiques et matériaux associés ; - dresser un bilan des sources de photons à haute énergie et de leurs applications courantes et futures ; - susciter de nouvelles collaborations ; - ouvrir de nouveaux champs disciplinaires. Elle a été organisée par le laboratoire CIRIL au VVF de Colleville-sur-Mer, dans le département du Calvados, du 6 au 9 juin 2006, la journée du 5 juin ayant été consacrée à une réunion de travail du GDR CNRS SAXO, ce GDR regroupant une majorité de scientifiques concernés par le Colloque UVX. La manifestation a réuni ainsi une centaine de participants dont une dizaine d'exposants industriels. Parmi ces participants, trente étaient invités à donner une conférence orale. Une sélection a été faite également parmi les meilleures communications soumises par affiches pour qu'elles soient présentées oralement. Une trentaine de ces communications ont été préparées sous la forme d'articles de 6 à 12 pages et font l'objet de cet ouvrage. De nombreux travaux récents ont été exposés tant au niveau des sources que des techniques de caractérisation et des applications, ceci dans des domaines très divers allant de la physique des lasers et de la mise en forme spatiale et temporelle des faisceaux au domaine de l'imagerie médicale et biologiques en passant par les techniques de fabrication des cristaux, fibres et films minces organiques et inorganiques. Plusieurs résultats marquants en sont ressortis. Dans le domaine des sources, la mise en forme spatiale du faisceau laser utilisé pour la production d'harmoniques d'ordre élevé dans les gaz, ceci à l'aide de lames de phase peu onéreuses et simples d'utilisation, semble être une bonne solution pour accroître les

  19. ESO PR Highlights in 2005

    NASA Astrophysics Data System (ADS)

    2006-01-01

    2005 was the year of Physics. It was thus also in part the year of astronomy and this is clearly illustrated by the numerous breakthroughs that were achieved, in particular using ESO's telescopes. One of the highlights was without any doubt the confirmation of the first image of an exoplanet , around the star 2M1207 (see ESO PR 12/05). ESO's telescopes also found a Neptune-mass exoplanet around a small star ( PR 30/05) - a discovery that proves crucial in the census of other planetary systems, and imaged a tiny companion in the close vicinity of the star GQ Lupi, a very young object still surrounded by a disc, with an age between 100,000 and 2 million years ( PR 09/05). Moreover, using a new high-contrast adaptive optics camera on the VLT, the NACO Simultaneous Differential Imager, or NACO SDI, astronomers were able for the first time to image a companion 120 times fainter than its star , very near the star AB Doradus A. This companion appears to be almost twice as heavy as theory predicts it to be ( PR 02/05). ESO's telescopes proved very useful in helping to solve a 30-year old puzzle . Astronomers have for the first time observed the visible light from a short gamma-ray burst (GRB). Using the 1.5m Danish telescope at La Silla (Chile), they showed that these short, intense bursts of gamma-ray emission most likely originate from the violent collision of two merging neutron stars ( PR 26/05). Additional evidence came from witnessing another event with the VLT ( PR 32/05). Also in this field, astronomers found the farthest known gamma-ray burst with ESO's VLT, observing an object with a redshift 6.3, i.e. that is seen when the Universe was less than 900 million years old ( PR 22/05). On July 4, NASA's Deep Impact spacecraft plunged onto Comet 9P/Tempel 1 with the aim to create a crater and expose pristine material from beneath the surface. For two days before and six days after, all major ESO telescopes have been observing the comet, in a coordinated fashion and in

  20. Directives préalables

    PubMed Central

    O’Sullivan, Rory; Mailo, Kevin; Angeles, Ricardo; Agarwal, Gina

    2015-01-01

    Résumé Objectif Établir la prévalence de patients dotés de directives préalables dans une pratique familiale et décrire les points de vue des patients quant au rôle du médecin de famille dans l’amorce de discussions à propos des directives préalables. Conception Un questionnaire auquel les patients ont répondu eux-mêmes. Contexte Une clinique d’enseignement en médecine familiale achalandée en milieu urbain, à Hamilton, en Ontario. Participants Un échantillon de commodité formé de patients adultes qui se sont présentés à la clinique durant une semaine de travail typique. Principaux paramètres à l’étude La prévalence des directives préalables dans une population de patients a été déterminée et les attentes à l’endroit du rôle de leur médecin de famille ont été sollicitées. Résultats Les répondants au sondage étaient au nombre de 800 (un taux de réponse de 72,5 %) et leurs groupes d’âges étaient bien répartis; 19,7 % d’entre eux avaient rédigé des directives préalables et 43,8 % avaient déjà discuté du sujet des directives préalables, mais seulement 4,3 % de ces discussions avaient eu lieu avec un médecin de famille. Dans 5,7 % des cas, un médecin de famille avait soulevé la question; 72,3 % des répondants croyaient que les patients devraient amorcer la discussion. Les patients qui considéraient les directives préalables d’une importance extrême étaient considérablement plus enclins à vouloir que leur médecin de famille commence la conversation (rapport de cotes de 3,98; p < ,05). Conclusion Les directives préalables n’étaient pas systématiquement abordées dans la pratique familiale. La plupart des patients préféraient amorcer la discussion des directives préalables. Toutefois, les patients qui considéraient le sujet d’une extrême importance voulaient que leur médecin de famille commence la discussion.

  1. Effect of Pr Valence State on Interfacial Structure and Electrical Properties of Pr Oxide/PrON/Ge Gate Stack Structure

    NASA Astrophysics Data System (ADS)

    Kato, Kimihiko; Sakashita, Mitsuo; Takeuchi, Wakana; Kondo, Hiroki; Nakatsuka, Osamu; Zaima, Shigeaki

    2011-04-01

    In this study, we investigated the valence state and chemical bonding state of Pr in a Pr oxide/PrON/Ge structure. We clarified the relationship between the valence state of Pr and the Pr oxide/Ge interfacial reaction using Pr oxide/Ge and Pr oxide/PrON/Ge samples. We found the formation of three Pr oxide phases in Pr oxide films; hexagonal Pr2O3 (h-Pr2O3) (Pr3+), cubic Pr2O3 (c-Pr2O3) (Pr3+), and c-PrO2 (Pr4+). We also investigated the effect of a nitride interlayer on the interfacial reaction in Pr oxide/Ge gate stacks. In a sample with a nitride interlayer (Pr oxide/PrON/Ge), metallic Pr-Pr bonds are also formed in the c-Pr2O3 film. After annealing in H2 ambient, the diffusion of Ge into Pr oxide is not observed in this sample. Pr-Pr bonds probably prevent the interfacial reaction and Ge oxide formation, considering that the oxygen chemical potential of this film is lower than that of a GeO2/Ge system. On the other hand, the rapid thermal oxidation (RTO) treatment terminates the O vacancies and defects in c-Pr2O3. As a result, c-PrO2 with tetravalent Pr is formed in the Pr oxide/PrON/Ge sample with RTO. In this sample, the leakage current density is effectively decreased in comparison with the sample without RTO. Hydrogen termination works effectively in Pr oxide/PrON/Ge samples with and without RTO, and we can achieve an interface state density of as low as 4 ×1011 eV-1·cm-2.

  2. Crystal structure, magnetic, and microwave properties of solid solutions BaFe12- x Ga x O19 (0.1 ≤ x ≤ 1.2)

    NASA Astrophysics Data System (ADS)

    Trukhanov, A. V.; Trukhanov, S. V.; Turchenko, V. A.; Oleinik, V. V.; Yakovenko, E. S.; Matsui, L. Yu.; Vovchenko, L. L.; Launets, V. L.; Kazakevich, I. S.; Dzhabarov, S. G.

    2016-09-01

    The crystal structure of solid solutions of an M-type hexagonal barium ferrite BaFe1- x Ga x O19 ( x = 0.1-1.2) with the isostructural diamagnetic substitution of Ga3+ ions has been studied by X-ray diffraction. The unit cell parameters have been calculated for all compositions. The field and temperature dependences of the specific magnetization of these solid solutions have been measured by vibrational magnetometry. The microwave properties of BaFe12- x Ga x O19 ( x = 0.1-1.2) have been studied in a bias field. It has been shown that the frequency of natural ferromagnetic resonance decreases as the Ga concentration increases from x = 0.1 to x = 0.6 and it increases once again as the Ga concentration increases to x = 1.2. As the Ga concentration increases, the natural ferromagnetic resonance lines broaden. This indicates an increase in the frequency range of strong absorption of electromagnetic radiation. In this case, the amplitude of the resonance curve peak changes insignificantly. The frequency shift of the natural ferromagnetic resonance in an external magnetic field increases as the gallium ion concentration in the sample decreases.

  3. Rietveld refinements of the solid solution Li{sub (1-2x)}Ni {sub x}TiO(PO{sub 4}) (0 {<=} x {<=} 0.50)

    SciTech Connect

    Manoun, B. . E-mail: manounb@fiu.edu; El Jazouli, A.; Gravereau, P.; Chaminade, J.P.

    2005-02-15

    Li{sub (1-2x)}Ni {sub x}TiO(PO{sub 4}) oxyphosphates with 0 {<=} x {<=} 0.10 crystallize in the orthorhombic system with the space group Pnma, those with 0.10 < x {<=} 0.25 crystallize in the monoclinic system with the space group P2{sub 1}/c and compositions with 0.25 < x < 0.50 present a mixture of the limit of the solid solution Li{sub 0.50}Ni{sub 0.25}TiO(PO{sub 4}) and Ni{sub 0.50}TiO(PO{sub 4}). The structure of the compositions 0 {<=} x {<=} 0.25 is based on a three-dimensional anionic framework constructed of chains of alternating TiO{sub 6} octahedra and PO{sub 4} tetrahedra, with the lithium and nickel atoms in the cavities in the framework. The dominant structural units in the compositions are chains of tilted corner-sharing TiO{sub 6} octahedra running parallel to one of the axis. The oxygen atoms of the shared corners, not implied in (PO{sub 4}) tetrahedra, justify the oxyphosphate designation. Titanium atoms are displaced from the geometrical center of the octahedra resulting in alternating long ({approx}2.25 A) and short ({approx}1.71 A) Ti-O(1) bonds. The four remaining Ti-O bond distances have intermediate values ranging from 1.91 to 2.06 A.

  4. Strongly-disordered hybridization and non-Fermi liquid behavior in CePt4Ge12-xSbx studied with thermoelectric power

    NASA Astrophysics Data System (ADS)

    White, Benjamin; Huang, Kevin; Maple, M. Brian

    2014-03-01

    Non-Fermi liquid (NFL) behavior is commonly associated with the presence of a nearby quantum critical point, but can also be observed in other scenarios. In a clean system, hybridization between localized and itinerant electron states can be characterized by a single Kondo temperature TK, but introducing chemical disorder can lead to a wide distribution of TK values. Given sufficient disorder, the resulting distribution will tend to include an appreciable number of localized electron states which are characterized by TK ~ 0 K, and NFL behavior emerges. A Kondo-disorder type of NFL behavior was recently reported in the filled skutterudite system CePt4Ge12-xSbx in the vicinity of x = 1 . We performed a study of the thermoelectric power S(T) for this system and observed an evolution of S(T) with x that is dramatic and broadly consistent with the boundaries of the proposed phase diagram. The effect of disordered hybridization is clearly observed in a low-temperature feature in S(T) in the range 0 . 5 <= x <= 1 . 5 and NFL behavior is also observed at x = 1. These results clearly demonstrate how sensitively S(T) is able to probe a Kondo disorder system. Research was performed with support from the US DOE grant DE-FG02-04-ER46105.

  5. DFT study of structural, electronic, and spectroscopic properties of D6d endohedral fullerenes: X@C24H12 (X=Li+, Na+, K+).

    PubMed

    Peng, Sheng; Li, Xiao Jun

    2009-07-01

    Based on the D6d-symmetrical C24H12, the equilibrium geometries, electronic structures, Infrared and Raman spectra, reaction energies, the energy gaps, and BSSE- and Zero-Point-corrected binding energies of endohedral fullerenes X@C24H12 (X=Li+, Na+, K+) have been calculated by first-principle density functional theory (DFT) at B3LYP/6-31G(d) level of theory. The results suggest that the average bond lengths of endohedral fullerenes are longer than those of the empty cage. And in the endohedral fullerenes, Li+@C24H12 is only favorable in energy, and can stably exist. The stable order of three endohedral fullerenes is Li+@C24H12>Na+@C24H12>K+@C24H12, this indicates that the reaction energies and binding energies are in excellent agreement with the energy gaps between the frontier orbitals in the aspect of stability. All may provide a theoretical reference for further applications in the fields of materials physics and chemistry.

  6. High magnetic ordering temperature in the perovskites Sr4-xLaxFe3ReO12 (x= 0.0, 1.0, 2.0)

    SciTech Connect

    Hodges, Jason P; Retuerto, Maria; Greenblatt, Martha; Li, Man-Rong; Croft, Mark; Ramanujachary, Kandalam V.; Go, Yong Bok; Nowik, Israel; Hadermann, Joke; Herber, R. H.; Ignatov, Alexander Y

    2012-01-01

    A series of perovskites Sr4-xLaxFe3ReO12 (x = 0.0, 1.0, 2.0) has been prepared by wet chemistry methods. The structure analyses by powder x-ray, neutron diffraction and electron microscopy show that these compounds adopt simple perovskite structures without cation ordering over the B sites: tetragonal (I4/mcm) for x = 0.0 and 1.0 and orthorhombic (Pbmn) for x = 2.0. The oxidation state of the cations in the compound with x = 0.0 appear to be Fe3+/4+ and Re7+ and decrease for both with La substitution as evidenced by x-ray absorption spectroscopy. All the compounds are antiferromagnetically ordered above room temperature, as demonstrated by M ssbauer spectroscopy and the magnetic structures, which were determined by powder neutron diffraction. The substitution of Sr by La strongly affects the magnetic properties with an increase of TN up to ~ 750 K.

  7. Giant magnetoresistance properties of the La1-2xRxAxMnO3 (R=Nd, A=Ca) perovskites

    NASA Astrophysics Data System (ADS)

    Kundaliya, Darshan C.; Tulapurkar, A. A.; Shinde, S. R.; Pinto, R.; Yelon, W. B.; Kulkarni, R. G.; Malik, S. K.

    2003-05-01

    The effect of simultaneous substitution of Nd and Ca in the antiferromagnetic insulator, LaMnO3, is studied by x-ray diffraction, magnetoresistance, and magnetization measurements. X-ray powder diffraction patterns of La1-2xNdxCaxMnO3 polycrystalline bulk samples for x=0.2, 0.33, and 0.4 confirm the single-phase formation of orthorhombic perovskite structure (space group Pbnm). The unit cell volume decreases with increasing Nd/Ca substitution. Changes in the temperature dependence of resistivity from semiconducting to metallic, and an increase of the ferromagnetic transition temperature, are observed in this series with increasing x. For x=0.2, 0.33, and 0.4, the metal-insulator transition temperature (Tp) is 72, 140, and 155 K, respectively, and the magnetoresistance (MR) observed in this system in 2 T applied magnetic field around Tp is 35%, 99% and 65%, respectively. The MR of 99% for the x=0.33 sample is promising for practical device applications where MR at low fields is of special interest. The magnetic moment values, obtained from the magnetization data in the magnetically ordered state, agree reasonably well with the free ion Mn moments for all the samples.

  8. Computational and Experimental Investigation of Ti Substitution in Li1(NixMnxCo1-2x-yTiy)O2 for Lithium Ion Batteries.

    PubMed

    Markus, Isaac M; Lin, Feng; Kam, Kinson C; Asta, Mark; Doeff, Marca M

    2014-11-01

    Aliovalent substitutions in layered transition-metal cathode materials has been demonstrated to improve the energy densities of lithium ion batteries, with the mechanisms underlying such effects incompletely understood. Performance enhancement associated with Ti substitution of Co in the cathode material Li1(NixMnxCo1-2x)O2 were investigated using density functional theory calculations, including Hubbard-U corrections. An examination of the structural and electronic modifications revealed that Ti substitution reduces the structural distortions occurring during delithiation due to the larger cation radius of Ti(4+) relative to Co(3+) and the presence of an electron polaron on Mn cations induced by aliovalent Ti substitution. The structural differences were found to correlate with a decrease in the lithium intercalation voltage at lower lithium concentrations, which is consistent with quasi-equilibrium voltages obtained by integrating data from stepped potential experiments. Further, Ti is found to suppress the formation of a secondary rock salt phase at high voltage. Our results provide insights into how selective substitutions can enhance the performance of cathodes, maximizing the energy density and lifetime of current Li ion batteries.

  9. Strong Infrared NLO Tellurides with Multifunction: CsX(II)4In5Te12 (X(II) = Mn, Zn, Cd).

    PubMed

    Lin, Hua; Liu, Yi; Zhou, Liu-Jiang; Zhao, Hua-Jun; Chen, Ling

    2016-05-01

    Chalcogenides are the most promising mid- and far-infrared materials for nonlinear optical (NLO) applications. Yet, most of them are sulfides and selenides, and tellurides are still rare. Herein, we report three new KCd4Ga5S12-structure type NLO-active tellurides, CsX(II)4In5Te12 (X(II) = Mn, Zn, Cd), synthesized by solid-state reactions. The structure features a 3D diamond-like framework constructed by vertex-sharing asymmetric MTe4 tetrahedra that are stacked along the c-axis. CsCd4In5Te12 exhibits the strongest powder second-harmonic generation (SHG) intensity at 2050 nm (0.61 eV) among tellurides to date, 9 × benchmark AgGaS2 in the range of 46-74 μm particle size. The primary studies reveal the 1.42 eV direct band gap and high absorption coefficient in the visible spectral region for CsCd4In5Te12, suggesting it is a new potential solar cell absorber material. In addition, CsMn4In5Te12 also displays a spin-canted antiferromagnetic property below 50 K.

  10. Strong Infrared NLO Tellurides with Multifunction: CsX(II)4In5Te12 (X(II) = Mn, Zn, Cd).

    PubMed

    Lin, Hua; Liu, Yi; Zhou, Liu-Jiang; Zhao, Hua-Jun; Chen, Ling

    2016-05-01

    Chalcogenides are the most promising mid- and far-infrared materials for nonlinear optical (NLO) applications. Yet, most of them are sulfides and selenides, and tellurides are still rare. Herein, we report three new KCd4Ga5S12-structure type NLO-active tellurides, CsX(II)4In5Te12 (X(II) = Mn, Zn, Cd), synthesized by solid-state reactions. The structure features a 3D diamond-like framework constructed by vertex-sharing asymmetric MTe4 tetrahedra that are stacked along the c-axis. CsCd4In5Te12 exhibits the strongest powder second-harmonic generation (SHG) intensity at 2050 nm (0.61 eV) among tellurides to date, 9 × benchmark AgGaS2 in the range of 46-74 μm particle size. The primary studies reveal the 1.42 eV direct band gap and high absorption coefficient in the visible spectral region for CsCd4In5Te12, suggesting it is a new potential solar cell absorber material. In addition, CsMn4In5Te12 also displays a spin-canted antiferromagnetic property below 50 K. PMID:27070041

  11. Void swelling at low displacement rates in annealed 12X18HgT stainless steel at 4-56 dpa and 280-332 °C

    NASA Astrophysics Data System (ADS)

    Porollo, S. I.; Konobeev, Yu. V.; Dvoriashin, A. M.; Vorobjev, A. N.; Krigan, V. M.; Garner, F. A.

    2002-12-01

    Water-cooled fusion devices most likely will have austenitic components that operate at temperatures below the inlet temperatures characteristic of high flux fast reactors used to generate majority of data on void swelling. Many of these components will experience displacement rates of 10 -7-10 -8 dpa/s that are lower than that of most in-core fast reactor experiments. One question of particular interest is how to define the lower limit of the temperature range over which void swelling can occur at such low dpa rates. This question was addressed using a flow restrictor component irradiated at 4-56 dpa and 280-332 °C in the low-flux breeder zone of the BN-350 fast reactor in Kazakhstan. This component was constructed of annealed 12X18HgT, an alloy similar to AISI 321. Extensive sectioning to produce 114 separate specimens, followed by examination of the radiation-induced microstructure showed that void swelling in the range of temperatures and dpa rates of interest occurs down to ˜300 °C.

  12. Transverse Wobbling in 135Pr

    NASA Astrophysics Data System (ADS)

    Matta, J. T.; Garg, U.; Li, W.; Frauendorf, S.; Ayangeakaa, A. D.; Patel, D.; Schlax, K. W.; Palit, R.; Saha, S.; Sethi, J.; Trivedi, T.; Ghugre, S. S.; Raut, R.; Sinha, A. K.; Janssens, R. V. F.; Zhu, S.; Carpenter, M. P.; Lauritsen, T.; Seweryniak, D.; Chiara, C. J.; Kondev, F. G.; Hartley, D. J.; Petrache, C. M.; Mukhopadhyay, S.; Lakshmi, D. Vijaya; Raju, M. Kumar; Madhusudhana Rao, P. V.; Tandel, S. K.; Ray, S.; Dönau, F.

    2015-02-01

    A pair of transverse wobbling bands is observed in the nucleus 135Pr . The wobbling is characterized by Δ I =1 , E 2 transitions between the bands, and a decrease in the wobbling energy confirms its transverse nature. Additionally, a transition from transverse wobbling to a three-quasiparticle band comprised of strong magnetic dipole transitions is observed. These observations conform well to results from calculations with the tilted axis cranking model and the quasiparticle rotor model.

  13. Experimental and DFT studies of structure, optical and magnetic properties of (Zn1-2xCexCox)O nanopowders

    NASA Astrophysics Data System (ADS)

    Arul Mary, J.; Judith Vijaya, J.; Dai, J. H.; Bououdina, M.; John Kennedy, L.; Song, Y.

    2015-03-01

    A simple one-step microwave-assisted combustion method using urea as a fuel, was applied to develop the nanophase powders of ((Zn1-2xCexCox) O (x = 0.00, 0.01, 0.02, 0.03, 0.04, and 0.05)). The results emphasize that by changing the codopant concentration it is feasible to fine-tune structural, morphological, optical and magnetic properties. The synthesized nanoparticles gave rise to new microstructures without changing the basic hexagonal wurtzite structure. The substitution of Ce and Co into ZnO lattice was confirmed from the shift in XRD peaks position, changes in peaks intensity, and cell parameters. Energy dispersive X-ray spectra confirmed the presence of Ce and Co within ZnO system; the weight percentage was close to their nominal stoichiometry. Ultraviolet-visible (UV-Vis) spectroscopy analysis indicated that the optical band gap decreased with the increase of Ce and Co codoping concentration. It is clear from SEM images that the average particles size decreased from 50 nm to 25 nm when codoping concentration was increased up to 0.05 M. Photoluminescence spectra exhibited the emission bands in ultra-violet and blue-green regions. Magnetization-Field (M-H) hysteresis loops revealed that the codoped nanopowders exhibited room temperature ferromagnetism (RTFM). Using first principles calculations, based on density functional theory, electronic and magnetic properties of codoped ZnO for different dopants concentration, were predicted. It is found that the observed RTFM is originated mainly from spin polarization of Co-d orbital, Ce-f orbital has partial contribution.

  14. Void Swelling at Low Displacement Rates in Annealed 12X18H9T Stainless Steel at 4 to 56 dpa and 280-332 degrees C

    SciTech Connect

    Porollo, S. I.; Konobeev, Yu V.; Dvoraishin, A. M.; Vorobjev, A. N.; Krigan, V M.; Garner, Francis A.

    2002-12-01

    Water-cooled fusion devices most likely will have austenitic components that operate at temperatures below the inlet temperatures characteristic of high flux fast reactors used to generate majority of data on void swelling. Many of these same locations will also experience displacement rates that are also lower than that of most in-core fast reactor experiments, 10-7 to 10-8 dpa/s. One question of particular interest is how to define the lower limit of the temperature range over which void swelling can occur, especially at such lower dpa rates. This question was addressed using a flow restrictor component from the low-flux breeder zone of the BN-350 fast reactor in Kazakhstan. This component was constructed of annealed 12X18H10T, an alloy similar to AISI 321. Extensive sectioning to produce 114 separate specimens, followed by examination of the radiation-induced microstructure showed that void swelling in the range of temperatures and dpa rates of interest occurs down to approximately 300 degrees C. At 330 degrees C the swelling reached approximately 1 percent at 20 dpa. Comparison of these data with other published data on this steel from Russian light water reactors at less than 10 dpa confirms that the lowest temperature that stainless steels can begin swelling also appears to be approximately 300 degrees C. Since fusion and LWR spectra generate similar levels of hydrogen and helium, it is expected that these conclusions are equally applicable to both types of reactors when operating at comparable dpa rates.

  15. μSR study of charge neutrally doped Y 1-2xCa xTh xBa 2Cu 3O 7- δ system covering the

    NASA Astrophysics Data System (ADS)

    Hartmann, O.; Karlsson, E.; Lidström, E.; Wäppling, R.; Lundqvist, P.; Hegedüs, Z.; Rapp, Ö.

    1994-12-01

    Muon spin relaxation measurements were performed on the Y 1-2xCa xTh xBa 2Cu 3O 7- δ solubility range for doping in the orthorhombic phase. The low temperature relaxation rate was found to decrease with CaTh concentration in the dilute range and to be constant for high doping levels.

  16. PrPs: Proteins with a purpose

    PubMed Central

    Sempou, Emily

    2009-01-01

    The best-known attribute of the prion protein (PrP) is its tendency to misfold into a rogue isoform. Much less understood is how this misfolded isoform causes deadly brain illnesses. Neurodegeneration in prion disease is often seen as a consequence of abnormal PrP function yet, amazingly little is known about the normal, physiological role of PrP. In particular, the absence of obvious phenotypes in PrP knockout mice has prevented scientists from answering this important question. Using knockdown approaches, we previously produced clear PrP loss-of-function phenotypes in zebrafish embryos. Analysis of these phenotypes revealed that PrP can modulate E-cadherin-based cell-cell adhesion, thereby controlling essential morphogenetic cell movements in the early gastrula. Our data also showed that PrP itself can elicit homophilic cell-cell adhesion and trigger intracellular signaling via Src-related kinases. Importantly, these molecular functions of PrP are conserved from fish to mammals. Here we discuss the use of the zebrafish in prion biology and how it may advance our understanding of the roles of PrP in health and disease. PMID:19786844

  17. Minority-spin t(2g) states and the degree of spin polarization in ferromagnetic metallic La(2-2x)Sr(1+2x)Mn(2)O(7) (x = 0.38).

    PubMed

    Sun, Z; Wang, Q; Douglas, J F; Lin, H; Sahrakorpi, S; Barbiellini, B; Markiewicz, R S; Bansil, A; Fedorov, A V; Rotenberg, E; Zheng, H; Mitchell, J F; Dessau, D S

    2013-11-07

    A half-metal is a material with conductive electrons of one spin orientation. This type of substance has been extensively searched for due to the fascinating physics as well as the potential applications for spintronics. Ferromagnetic manganites are considered to be good candidates, though there is no conclusive evidence for this notion. Here we show that the ferromagnet La2-2xSr1+2xMn2O7 (x = 0.38) possesses minority-spin states, challenging whether any of the manganites may be true half-metals. However, when electron transport properties are taken into account on the basis of the electronic band structure, we found that the La2-2xSr1+2xMn2O7 (x = 0.38) can essentially behave like a complete half metal.

  18. Minority-spin t2g states and the degree of spin polarization in ferromagnetic metallic La2−2xSr1+2xMn2O7 (x = 0.38)

    PubMed Central

    Sun, Z.; Wang, Q.; Douglas, J. F.; Lin, H.; Sahrakorpi, S.; Barbiellini, B.; Markiewicz, R. S.; Bansil, A.; Fedorov, A. V.; Rotenberg, E.; Zheng, H.; Mitchell, J. F.; Dessau, D. S.

    2013-01-01

    A half-metal is a material with conductive electrons of one spin orientation. This type of substance has been extensively searched for due to the fascinating physics as well as the potential applications for spintronics. Ferromagnetic manganites are considered to be good candidates, though there is no conclusive evidence for this notion. Here we show that the ferromagnet La2−2xSr1+2xMn2O7 (x = 0.38) possesses minority-spin states, challenging whether any of the manganites may be true half-metals. However, when electron transport properties are taken into account on the basis of the electronic band structure, we found that the La2−2xSr1+2xMn2O7 (x = 0.38) can essentially behave like a complete half metal. PMID:24196704

  19. ESO PR Highlights in 2003

    NASA Astrophysics Data System (ADS)

    2004-01-01

    Among the many astronomical highlights of 2003, the Transit of Mercury certainly attracted great attention as shown by the record number of hits the ESO web page received on that day. But this was a mere rehearsal of an even bigger event we will enjoy in 2004: the Venus Transit. ESO, in partnership with several institutions, is organising a major educational event in connection with it. During 2003, the ESO Educational Office was also involved in various other programmes. They included the web-based "Catch a Star!" and the "Physics and Life" projects, organised with EC sponsorship in connection with the 2003 European Science and Technology Week. The ALMA project, an European-North American collaboration to build an array of 64 12-m submillimetre antennas, moved forward with the signature of the agreement between ESO and the NSF and with the Ground-breaking at Chajnantor. Conceptual studies of a 100-m optical/infrared telescope (OWL) also proceeded well. Several new instruments were installed at ESO telescopes, e.g. HARPS . And the VLT Interferometer (VLTI) received a powerful Adaptive Optics System and made the first detection through infrared interferometry of an extragalactic object. A rapidly increasing number of new scientific results were obtained on the basis of data from ESO telescopes, some of which were highlighted in ESO Press Releases. A number of beautiful images were published. Many of these developments are described in ESO's Press Releases, most with Press Photos, cf. the 2003 PR Index. Some of last year's ESO PR highlights may be accessed directly via the clickable image above.

  20. Characterization of thin films of the solid electrolyte Li(x)Mg(1-2x)Al(2+x)O4 (x = 0, 0.05, 0.15, 0.25).

    PubMed

    Put, Brecht; Vereecken, Philippe M; Mees, Maarten J; Rosciano, Fabio; Radu, Iuliana P; Stesmans, Andre

    2015-11-21

    RF-sputtered thin films of spinel Li(x)Mg(1-2x)Al(2+x)O4 were investigated for use as solid electrolyte. The usage of this material can enable the fabrication of a lattice matched battery stack, which is predicted to lead to superior battery performance. Spinel Li(x)Mg(1-2x)Al(2+x)O4 thin films, with stoichiometry (x) ranging between 0 and 0.25, were formed after a crystallization anneal as shown by X-ray diffraction and transmission electron microscopy. The stoichiometry of the films was evaluated by elastic recoil detection and Rutherford backscattering and found to be slightly aluminum rich. The excellent electronic insulation properties were confirmed by both current-voltage measurements as well as by copper plating tests. The electrochemical stability window of the material was probed using cyclic voltammetry. Lithium plating and stripping was observed together with the formation of a Li-Pt alloy, indicating that Li-ions passed through the film. This observation contradicted with impedance measurements at open circuit potential, which showed no apparent Li-ion conductivity of the film. Impedance spectroscopy as a function of potential showed the occurrence of Li-ion intercalation into the Li(x)Mg(1-2x)Al(2+x)O4 layers. When incorporating Li-ions in the material the ionic conductivity can be increased by 3 orders of magnitude. Therefore it is anticipated that the response of Li(x)Mg(1-2x)Al(2+x)O4 is more adequate for a buffer layer than as the solid electrolyte.

  1. Structure and magnetic properties of Pr10(Fe,Co,Ni)84B6 nanocomposite alloys

    NASA Astrophysics Data System (ADS)

    Daniil, M.; Minter, L.; Willard, M. A.

    2012-04-01

    Nanocomposite ribbons with composition Pr10(Fe1-2xCoxNix)84B6 (x = 0.0, 0.05, 0.10, and 0.15) were prepared by melt-spinning. All melt-spun ribbons are composed of a fine mixture of 2:14:1 and bcc-(Fe,Co,Ni) phases with an additional soft phase (Pr2Fe23B3-based) for x = 0.10 and 0.15. The room temperature coercivity decreases from 7.4 to 2 kOe with Co and Ni substitutions likely due to the decrease of the magnetocrystalline anisotropy of the 2:14:1 phase and the increase of the amount of the soft phases. Saturation magnetization increases slightly while remanence and (BH)max show a slight decrease for x up to 0.10 and then they drop quickly. The intergranular exchange coupling is strong for x ≤ 0.10 but it is reduced significantly for x = 0.15 due to the substantial increase of the volume and size of the soft phases. Thermomagnetic measurements showed a significant increase of the Curie temperature of the 2:14:1 phase from 290 °C for x = 0 to 485 °C for x = 0.15. High temperature hysteresis loop measurements showed improved temperature dependence of remanence and coercivity for x = 0.05.

  2. Investigation of the superconducting and normal state properties of the filled-skutterudite system PrPt4Ge12 via chemical substitution

    NASA Astrophysics Data System (ADS)

    Jeon, Inho; Huang, Kevin; Yazici, Duygu; Kanchanavatee, Noravee; White, Benjamin D.; Jang, Sooyoung; Pouse, Naveen; Maple, M. Brian; Ho, Pei-Chun

    We report a systematic chemical substitution study on the unconventional superconductor system PrPt4Ge12, which Sb ions are substituted for Ge. Polycrystalline samples of PrPt4Ge12-x Sbx up to x = 5 were synthesized and investigated by means of x-ray diffraction, electrical resistivity, magnetic susceptibility, and specific heat measurements. We observed a suppression of superconductivity with increasing Sb substitutions and evidence for a weak ``rattling'' mode associated with the Pr ions, characterized by a value of ΘE ~ 60 K. As part of a systematic study of the effect of various elemental substitutions on the properties of PrPt4Ge12, measurements of the superconducting and normal state properties of the Pr1-xEuxPt4Ge12 system are currently being performed. This work was supported by the U. S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Grant No. DE-FG02-04-ER46105 (characterization and physical properties measurements), and the National Science Foundation under Grant No. DMR 1206553 (low-temperature measurements).

  3. Practical PR for School Media Centers.

    ERIC Educational Resources Information Center

    Beasley, Augie E.; Palmer, Carolyn G.

    This guide to public relations (PR) for school media specialists begins with a list of 10 "PR Commandments" and suggestions for ways to improve the media center's image, i.e., a media newsletter; renewal workshops; reference skills units; a student brochure; new faculty orientation; media messages; a happenings board; displays, centers, and…

  4. THERMOELECTRIC PROPERTIES OF p-TYPE SKUTTERUDITES (Pr0.25Nd0.75)xFe3CoSb12 BY LEVITATION MELTING AND SPARK PLASMA SINTERING

    NASA Astrophysics Data System (ADS)

    Xu, Jingshu; Fu, Chenguang; Xie, Jian; Zhao, Xinbing; Zhu, Tiejun

    2013-10-01

    The p-type skutterudite compounds of (Pr0.25Nd0.75)xFe3CoSb12 (x = 0.67-0.78) have been successfully synthesized by levitation melting followed by annealing and spark plasma sintering. The thermoelectric properties have been characterized by the measurements of Seebeck coefficient, electrical conductivity and thermal conductivity in the temperature range from 300 K to 850 K. The improvement in the thermoelectric properties was realized due to the reduction in the lattice thermal conductivity when the voids were partially filled by Pr0.25Nd0.75. The maximum ZT value of 0.83 for (Pr0.25Nd0.75)0.76Fe3CoSb12 was obtained at 700 K.

  5. [Functions of prion protein PrPc].

    PubMed

    Cazaubon, Sylvie; Viegas, Pedro; Couraud, Pierre-Olivier

    2007-01-01

    It is now well established that both normal and pathological (or scrapie) isoforms of prion protein, PrPc and PrPsc respectively, are involved in the development and progression of various forms of neurodegenerative diseases, including scrapie in sheep, bovine spongiform encephalopathy (or "mad cow disease") and Creutzfeldt-Jakob disease in human, collectively known as prion diseases. The protein PrPc is highly expressed in the central nervous system in neurons and glial cells, and also present in non-brain cells, such as immune cells or epithelial and endothelial cells. Identification of the physiological functions of PrPc in these different cell types thus appears crucial for understanding the progression of prion diseases. Recent studies highlighted several major roles for PrPc that may be considered in two major domains : (1) cell survival (protection against oxidative stress and apoptosis) and (2) cell adhesion. In association with cell adhesion, distinct functions of PrPc were observed, depending on cell types : neuronal differentiation, epithelial and endothelial barrier integrity, transendothelial migration of monocytes, T cell activation. These observations suggest that PrPc functions may be particularly relevant to cellular stress, as well as inflammatory or infectious situations. PMID:17875293

  6. Power-law index and penetration depth of (NdxSmxGd1-2x)Ba2Cu3O7-δ films studied by AC susceptibility

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Fen; He, Dong; Grivel, Jean-Claude

    2012-12-01

    Superconducting (NdxSmxGd1-2x)Ba2Cu3O7-δ films with x=0, 0.1, 0.25, 0.33 were grown by PLD on STO single crystal substrates. The power-law index n and penetration depth λ are studied by AC susceptibility. During cooling, n in films with x ≠ 0 increases much slower compared with the films with x = 0. The films with x ≠ 0 also tend to have a longer penetration depth. These properties might be related to the higher possibility for disorder in the mixed (Nd,Sm,Gd)BCO films.

  7. Surface- and bulk-sensitive x-ray absorption study of the valence states of Mn and Co ions in Zn1-2xMnxCoxO nanoparticles

    NASA Astrophysics Data System (ADS)

    Kataoka, T.; Yamazaki, Y.; Sakamoto, Y.; Fujimori, A.; Chang, F.-H.; Lin, H.-J.; Huang, D. J.; Chen, C. T.; Tanaka, A.; Mandal, S. K.; Nath, T. K.; Karmakar, D.; Dasgupta, I.

    2010-06-01

    We have performed x-ray absorption spectroscopy (XAS) measurements on Zn1-2xMnxCoxO nanoparticles. From the XAS results, it seems that the Mn and Co ions are in a mixed-valence (2+, 3+, and 4+) state and the relative concentrations of the high-valence (3+ and 4+) Mn and Co ions are higher in the surface region than in the deep core region. We suggest that this is a distinct trend of nanoparticle diluted magnetic semiconductor (DMS) unlike the case of DMS in film and bulk forms, where the transition-metal ions are expected to be 2+.

  8. Optimization of permanent magnetic properties in melt spun Co{sub 82−x}Hf{sub 12+x}B{sub 6} (x = 0–4) nanocomposites

    SciTech Connect

    Chang, H. W.; Liao, M. C.; Shih, C. W.; Chang, W. C.; Shaw, C. C.

    2015-05-07

    Magnetic properties of melt spun Co{sub 82−x}Hf{sub 12+x}B{sub 6} ribbons made with various wheel speeds have been studied. The ribbons with x = 0–1 are not easy to crystallize and thus display soft magnetic behavior even at wheel speed of 10 m/s. In contrast, the ribbons with x = 1.5–4 at optimized wheel speed exhibit good permanent magnetic properties of B{sub r} = 0.41–0.59 T, {sub i}H{sub c} = 120–400 kA/m, and (BH){sub max} = 10.6–48.1 kJ/m{sup 3}. The optimal magnetic properties of B{sub r} = 0.59 T, {sub i}H{sub c} = 384 kA/m, and (BH){sub max} = 48.1 kJ/m{sup 3} are achieved for Co{sub 80}Hf{sub 14}B{sub 6} ribbons at wheel speed of 30 m/s. X-ray diffraction, thermo-magnetic analysis, and transmission electron microscopy results show that good hard magnetic properties of Co{sub 82−x}Hf{sub 12+x}B{sub 6} ribbons (x = 2–4) are originated from the Co{sub 11}Hf{sub 2} phase well coupled with the Co phase. The change of magnetic properties for Co{sub 82−x}Hf{sub 12+x}B{sub 6} ribbons spun at various wheel speeds is correlated to microstructure and phase constitution. The strong exchange-coupling effect between magnetic grains for the ribbons with x = 2–3 at wheel speed = 30 m/s leads to remarkable permanent magnetic properties. The presented results suggest that the optimized Co{sub 82−x}Hf{sub 12+x}B{sub 6} (x = 2–3) ribbons are much suitable than others (x = 0–1.5 and 4) for making rare earth and Pt-free magnets.

  9. Photoheterotrophic growth of Agmenellum quadruplicatum PR-6

    SciTech Connect

    Lambert, D.H.; Stevens, S.E. Jr.

    1986-02-01

    The unicellular cyanobacterium Agmenellum quadruplicatum PR-6 grows in the presence of light on agar containing 10 ..mu..M 3-(3,4 dichlorophenyl)-1,1-dimethylurea and 1 to 30 mM glycerol. A derivative strain, PR-6G2, was tolerant of 100 mM glycerol. Photoheterotrophic growth conditions had little effect on transformation competence but did decrease the viability of single cells plated onto agar, particularly cells of the parent strain.

  10. PrEP: controversy, agency and ownership

    PubMed Central

    Cairns, Gus P; Race, Kane; Goicochea, Pedro

    2016-01-01

    Pre-exposure prophylaxis (PrEP) has been and continues to be an intervention that causes controversy and debate between stakeholders involved in providing or advocating for it, and within communities in need of it. These controversies extend beyond the intrinsically complex issues of making it available. In this commentary, some of the possible roots of the air of dissent and drama that accompanies PrEP are explored. The similarities between the controversies that dogged the earliest human trials of PrEP and the ones we see today in the era of licensing and implementation are explored. We outline five mediating principles or cultural norms that may influence arguments about PrEP differently. Three areas of specific concern are identified: medical risk versus benefit, distrust and fear of healthcare interventions, and fears for individual responsibility and community cohesion. The fear that PrEP may somehow represent a loss of control over one or more of these domains is suggested as an underlying factor. The development of countervailing measures, to institute greater community “ownership” of PrEP, and concomitant improvements in the sense of individual agency over sexual risk are outlined and recommended. PMID:27760689

  11. Superior Na-Storage Performance of Low-Temperature-Synthesized Na3(VO(1-x)PO4)2F(1+2x) (0≤x≤1) Nanoparticles for Na-Ion Batteries.

    PubMed

    Qi, Yuruo; Mu, Linqin; Zhao, Junmei; Hu, Yong-Sheng; Liu, Huizhou; Dai, Sheng

    2015-08-17

    Na-ion batteries are becoming comparable to Li-ion batteries because of their similar chemical characteristics and abundant sources of sodium. However, the materials production should be cost-effective in order to meet the demand for large-scale application. Here, a series of nanosized high-performance cathode materials, Na3(VO(1-x)PO4)2F(1+2x) (0≤x≤1), has been synthesized by a solvothermal low-temperature (60-120 °C) strategy without the use of organic ligands or surfactants. The as-synthesized Na3(VOPO4)2F nanoparticles show the best Na-storage performance reported so far in terms of both high rate capability (up to 10 C rate) and long cycle stability over 1200 cycles. To the best of our knowledge, the current developed synthetic strategy for Na3(VO(1-x)PO4)2F(1+2x) is by far one of the least expensive and energy-consuming methods, much superior to the conventional high-temperature solid-state method.

  12. Effect of La-CO substitution on the crystal structure and magnetic properties of low temperature sintered Sr1-xLaxFe12-xCoxO19 (x=0-0.5) ferrites

    NASA Astrophysics Data System (ADS)

    Peng, Long; Li, Lezhong; Wang, Rui; Hu, Yun; Tu, Xiaoqiang; Zhong, Xiaoxi

    2015-11-01

    The La-Co substituted Sr1-xLaxFe12-xCoxO19 (x=0-0.5) ferrites with appropriate Bi2O3 additive were prepared at a low sintering temperature of 890 °C compatible with LTCC (low temperature co-fired ceramics) systems, and the effect of La-Co substitution on their crystal structure and magnetic properties was investigated. The results show that the pure M-type phase is successfully obtained when the La-Co substitution amount x does not exceed 0.3. However, the single M-type phase structure transforms to multiphase structure with further increased x, where the α-Fe2O3 phase and La2O3 phase coexist with the M-type phase. Moreover, the saturation magnetization Ms, magnetic anisotropy field Ha, intrinsic coercivity Hci, and Curie temperature TC of the ferrites depend on the La-Co substitution amount strongly, which are suggested to be determined by the partially substitution of La3+-Co2+ ions for Sr2+-Fe3+ ions with x not higher than 0.3. It is found that the obtained Sr1-xLaxFe12-xCoxO19 (x=0.2 and 0.3) ferrites can provide improved magnetic properties (Ms>62 emu/g, Ha>1400 kA/m, and Hci>320 kA/m) as low temperature sintered M-type hexaferrites for microwave LTCC applications.

  13. ESO PR Highlights in 2007

    NASA Astrophysics Data System (ADS)

    2008-01-01

    Another great year went by for ESO, the European Organisation for Astronomical Research in the Southern Hemisphere. From 1 January 2007, with the official joining of the Czech Republic, ESO has 13 member states, and since September, ESO has a new Director General, Tim de Zeeuw (ESO 03/07 and 38/07). Many scientific discoveries were made possible with ESO's telescopes. Arguably, the most important is the discovery of the first Earth-like planet in the habitable zone of a low-mass red dwarf (ESO 22/07). If there is water on this planet, then it should be liquid! ESO PR Highlights 2007 This is a clickable map. These are only some of the press releases issued by ESO in 2007. For a full listing, please go to ESO 2007 page. In our own Solar System also, astronomers made stunning breakthroughs with ESO's telescopes, observing the effect of the light from the Sun on an asteroid's rotation (ESO 11/07), describing in unprecedented detail the double asteroid Antiope (ESO 18/07), peering at the rings of Uranus (ESO 37/07), discovering a warm south pole on Neptune (ESO 41/07), showing a widespread and persistent morning drizzle of methane over the western foothills of Titan's major continent (ESO 47/07), and studying in the greatest details the wonderful Comet McNaught (ESO 05/07 and 07/07). In the study of objects slightly more massive than planets, the VLT found that brown dwarfs form in a similar manner to normal stars (ESO 24/07). The VLT made it also possible to measure the age of a fossil star that was clearly born at the dawn of time (ESO 23/07). Other discoveries included reconstructing the site of a flare on a solar-like star (ESO 53/07), catching a star smoking (ESO 34/07), revealing a reservoir of dust around an elderly star (ESO 43/07), uncovering a flat, nearly edge-on disc of silicates in the heart of the magnificent Ant Nebula (ESO 42/07), finding material around a star before it exploded (ESO 31/07), fingerprinting the Milky Way (ESO 15/07), revealing a rich

  14. Correlation between Pr1 and Pr2 gene content and virulence in Metarhizium anisopliae strains.

    PubMed

    Rosas-García, Ninfa M; Avalos-de-León, Osvaldo; Villegas-Mendoza, Jesús M; Mireles-Martínez, Maribel; Barboza-Corona, J E; Castañeda-Ramírez, J C

    2014-11-28

    Metarhizium anisopliae is a widely studied model to understand the virulence factors that participate in pathogenicity. Proteases such as subtilisin-like enzymes (Pr1) and trypsin-like enzymes (Pr2) are considered important factors for insect cuticle degradation. In four M. anisopliae strains (798, 6342, 6345, and 6347), the presence of pr1 and pr2 genes, as well as the enzymatic activity of these genes, was correlated with their virulence against two different insect pests. The 11 pr1 genes (A, B, C, D, E, F, G, H, I, J, and K) and pr2 gene were found in all strains. The activity of individual Pr1 and Pr2 proteases exhibited variation in time (24, 48, 72, and 96 h) and in the presence or absence of chitin as the inductor. The highest Pr1 enzymatic activity was shown by strain 798 at 48 h with chitin. The highest Pr2 enzymatic activity was exhibited by the 6342 and 6347 strains, both grown with chitin at 24 and 48 h, respectively. Highest mortality on S. exigua was caused by strain 6342 at 48 h, and strains 6342, 6345, and 6347 caused the highest mortality 7 days later. Mortality on Prosapia reached 30% without variation. The presence of subtilisin and trypsin genes and the activity of these proteases in M. anisopliae strains cannot be associated with the virulence against the two insect pests. Probably, subtilisin and trypsin enzyme production is not a vital factor for pathogenicity, but its contribution is important to the pathogenicity process.

  15. Luminescence of Pr 3+ in minerals

    NASA Astrophysics Data System (ADS)

    Gaft, Michael; Reisfeld, Renata; Panczer, Gerard; Uspensky, Eugene; Varrel, Bernard; Boulon, Georges

    1999-10-01

    Time-resolved luminescence spectroscopy coupled with selective excitation allows one to identify and assign the emission transitions of Pr 3+ in natural apatite, scheelite and anhydrite. Under steady state conditions they are hidden by the stronger bands and lines of Eu 2+, (WO 4) 2-, (MoO 4) 2-, Sm 3+ and Dy 3+. Of special interest are the transitions from the 1S 0 level emitting in the UV part of the spectrum. These transitions make Pr 3+ doped oxyapatite and anhydrite potential materials for UV laser. The long-lived luminescence of Pr 3+ in the visible range in apatite in the presence of uranyl and in scheelite may be ascribed to the participation of the 1S 0 level which serves as a trap of the excitation.

  16. High magnetic ordering temperature in the perovskites Sr{sub 4-x}La{sub x}Fe{sub 3}ReO{sub 12} (x=0.0, 1.0, 2.0)

    SciTech Connect

    Retuerto, M.; Li, M.-R.; Go, Y.B.; Ignatov, A.; Croft, M.; Ramanujachary, K.V.; Herber, R.H.; Nowik, I.; Hodges, J.P.; Dachraoui, W.; Hadermann, J.; Greenblatt, M.

    2012-10-15

    A series of perovskites Sr{sub 4-x}La{sub x}Fe{sub 3}ReO{sub 12} (x=0.0, 1.0, 2.0) has been prepared by wet chemistry methods. The structure analyses by powder X-ray and neutron diffraction and electron microscopy show that these compounds adopt simple perovskite structures without cation ordering over the B sites: tetragonal (I4/mcm) for x=0.0 and 1.0 and orthorhombic (Pbmn) for x=2.0. The oxidation states of the cations in the compound with x=0.0 appear to be Fe{sup 3+/4+} and Re{sup 7+} and decrease for both with La substitution as evidenced by X-ray absorption spectroscopy. All the compounds are antiferromagnetically ordered above room temperature, as demonstrated by Moessbauer spectroscopy and the magnetic structures, which were determined by powder neutron diffraction. The substitution of Sr by La strongly affects the magnetic properties with an increase of T{sub N} up to {approx}750 K. - Graphical abstract: High resolution transmission electron microscopy image of Sr{sub 4-x}La{sub x}Fe{sub 3}ReO{sub 12} (x=2.0), showing twin domains. Fourier transforms are given of the areas indicated by the circles. Highlights: Black-Right-Pointing-Pointer Sr{sub 4-x}La{sub x}Fe{sub 3}ReO{sub 12} (x=0.0, 1.0, 2.0) perovskites prepared by wet chemistry. Black-Right-Pointing-Pointer PXD, PND, ED, indicate no cation ordering, I4/mcm) for x=0.0, 1.0, Pbmn for x=2. Black-Right-Pointing-Pointer XAS show oxidation states Fe{sup 3+/4+} and Re{sup 7+}; both decrease with increasing x. Black-Right-Pointing-Pointer All order antiferromagnetically above RT, with highest T{sub N} {approx}750 K.

  17. Investigation of the crystal and magnetic structures of BaFe{sub 12-x}Al{sub x}O{sub 19} solid solutions (x = 0.1‒1.2)

    SciTech Connect

    Turchenko, V. A.; Trukhanov, A. V.; Bobrikov, I. A.; Trukhanov, S. V.; Balagurov, A. M.

    2015-09-15

    The structure of barium ferrite BaFe{sub 12-x}Al{sub x}O{sub 19} solid solutions (x = 0.1‒1.2) with iron partially replaced with diamagnetic aluminum ions has been studied by neutron diffraction. Experimental data have been collected at room temperature on a high-resolution diffractometer, which yielded precise information about the changes in the crystal and magnetic structures and data on the behavior of the sample microstructure. Barium hexaferrite retains a magnetoplumbite structure in the entire range of aluminum concentrations under study, and its magnetic structure is described within the Gorter model, with moments orientated along the hexagonal axis. The total magnetic moment per formula unit decreases while diamagnetic aluminum ions substitute for iron ions. Microstrains in crystallites increase with an increase in the diamagnetic ion concentration, which is related to the difference in the ionic radii of iron and aluminum ions.

  18. Synthesis and luminescence properties of (Lu0.95‑xCe0.05)2Ca1+2xMg2Si3O12 silicate garnet phosphors and its applications

    NASA Astrophysics Data System (ADS)

    Xia, Wei; Zhang, Xiyan; Lu, Liping

    2016-06-01

    Silicate garnet phosphors (Lu0.95‑xCe0.05)2Ca1+2xMg2Si3O12 with x=0, 0.05, 0.1, and 0.15 were prepared by high-temperature solid-state reaction in a reducing atmosphere. The crystal structure, photoluminescence and luminescence of the phosphors were investigated. The optimum excitation peak wavelength of the phosphors ranged from 450nm to 490nm, matching the emission spectra of a blue light-emitting diode chip. The phosphors emit orange-red light after excitation that can be tuned from 589nm to 597nm by changing the concentration of calcium ions. In addition, their emission made them suitable for use in warm-white LEDs with a high-color rendering index.

  19. Observation of electronic inhomogeneity and charge density waves in a bilayer La(2-2x)Sr(1+2x)Mn2O7 single crystal.

    PubMed

    Kim, Jeehoon; Huang, Junwei; Zhou, J-S; Goodenough, J B; Zheng, H; Mitchell, J F; de Lozanne, Alex

    2013-05-24

    We employed a scanning tunneling microscope to image the (001) surface topography and local density of states (LDOS) in La(2-2x)Sr(1+2x)Mn(2)O(7) (x=0.32, LSMO) single crystals below the Curie temperature (T(C)≈120 K). The LDOS maps revealed a stripelike modulation propagating along the tetragonal a axis with a wavelength of about 16 Å, which is indicative of a charge density wave (CDW). The observed CDW in the x=0.32 sample is far from the Fermi surface nesting instability as compared with the data of angle resolved photoemission spectroscopy in an x=0.40 sample. The stripe model developed previously for cuprates can explain the observed CDW in our LSMO sample, indicating that competing interactions between localized and itinerant phases are the origin of the spatial modulations present intrinsically in cuprates and manganites.

  20. Two-fermion-four-boson description of {sup 198}Hg within the U{sub {nu}}(6/12) x U{sub {pi}}(6/4) extended nuclear structure supersymmetry

    SciTech Connect

    Bernards, C.; Heinze, S.; Jolie, J.; Fransen, C.; Linnemann, A.; Radeck, D.

    2009-05-15

    Using the U{sub {nu}}(6/12) x U{sub {pi}}(6/4) extended supersymmetry, we constructed the energy spectrum and electromagnetic transition properties of the supermultiplet member {sup 198}Hg with two proton fermions coupled to a neutron boson core. Consistency between the supersymmetric interacting boson fermion fermion approximation (IBFFA) description and the F-spin symmetric interacting boson approximation (IBA-2) description is shown for this two-fermion-N-boson multiplet member. The data of a {gamma}{gamma} angular correlation experiment using the HORUS cube {gamma}-ray spectrometer--determining new multipole mixing ratios, level spins, {gamma} transitions, and energy states--shows quite a good agreement, also for the low-energy part of the spectrum, when comparing theoretical predictions and experimental data. This is contrary to the usual assumption that a two-fermion-N-boson constellation should describe just the excited two-quasiparticle states.

  1. Magnetic domain tuning and the emergence of bubble domains in the bilayer manganite La2-2xSr1+2xMn2O7(x=0.32)

    DOE PAGES

    Jeong, Juyoung; Yang, Ilkyu; Yang, Jinho; Ayala-Valenzuela, Oscar E.; Wulferding, Dirk; Zhou, J. -S.; Goodenough, John B.; de Lozanne, Alex; Mitchell, J. F.; Leon, Neliza; et al

    2015-08-01

    Here, we report a magnetic force microscopy study of the magnetic domain evolution in the layered manganite La2–2xSr1+2xMn2O7 (with x = 0.32). This strongly correlated electron compound is known to exhibit a wide range of magnetic phases, including a recently uncovered biskyrmion phase. We observe a continuous transition from dendritic to stripelike domains, followed by the formation of magnetic bubbles due to a field- and temperature-dependent competition between in-plane and out-of-plane spin alignments. The magnetic bubble phase appears at comparable field and temperature ranges as the biskyrmion phase, suggesting a close relation between both phases. Based on our real-space imagesmore » we construct a temperature-field phase diagram for this composition.« less

  2. The enthalpies of formation of AsX(n) molecules, where X=H, F or Cl, and n=1, 2 or 3, by RCCSD(T) and UCCSD(T)-F12x calculations.

    PubMed

    Mok, Daniel K W; Lee, Edmond P F; Chau, Foo-Tim; Dyke, John M

    2011-05-28

    RCCSD(T) and UCCSD(T)-F12x calculations were performed on AsX(n) molecules, where X = H, F or Cl, and n = 1, 2 or 3, and related species, in order to evaluate their enthalpies of formation (ΔH(f)(Ø)). The recommended ΔH(f)(Ø) values obtained from the present investigation are AsH, 57.7(2); AsF, -7.9(3); AsCl, 27.2(4); AsH(2), 39.8(4); AsF(2), -96.6(9); AsCl(2), -17.8(10); AsH(3), 17.1(4); AsF(3)-196.0(5) and AsCl(3), -59.1(27) kcal mole(-1). These values are anchored only on one thermodynamic quantity, namely, ΔH(f)(Ø)(As) (= 70.3 kcal mole(-1)). In the calculations, the fully-relativistic small-core effective core potential (ECP10MDF) was used for As. Contributions from outer core correlation of As 3d(10) electrons were computed explicitly in both RCCSD(T) and UCCSD(T)-F12 calculations with additional tight basis functions designed for As 3d(10) electrons. Basis sets of up to augmented correlation-consistent polarized valence quintuple-zeta (aug-cc-pV5Z) quality were used in RCCSD(T) calculations and computed relative electronic energies were extrapolated to the complete basis set (CBS) limit. For the simplified, explicitly correlated UCCSD(T)-F12x calculations, basis sets of up to quadruple-zeta (QZ) quality were employed. Based on the RCCSD(T)/CBS benchmark values, the reliability of available theoretical and experimental values have been assessed.

  3. Correlations between lithium local structure and electrochemistry of layered LiCo(1-2x)Ni(x)Mn(x)O2 oxides: 7Li MAS NMR and EPR studies.

    PubMed

    Stoyanova, Radostina; Ivanova, Svetlana; Zhecheva, Ekaterina; Samoson, Ago; Simova, Svetlana; Tzvetkova, Pavleta; Barra, Anne-Laure

    2014-02-14

    Advanced (7)Li MAS NMR technologies and high frequency EPR are combined to identify structural motifs and their relation to electrochemical properties of layered lithium-cobalt-nickel-manganese oxides LiCo1-2xNixMnxO2 (0 < x ≤ 0.5) used as cathode materials in lithium ion batteries. Structural-chemical shift regularities were established by systematic variation of the ratio of diamagnetic Co(3+) to paramagnetic Ni/Mn ions with variable valences. While EPR allows identifying the oxidation state of transition metal ions inside the layers, (7)Li NMR probes the local structure of Li with respect to transition metal ions located in two adjacent layers. For assignment of the lithium chemical shifts, we examine first magnetically diluted LiCo1-2xNixMnxO2 with x = 0.02, where paramagnetic ions are stabilized only in Mn(4+) and Ni(3+) form. Then the studies are extended towards the intermediate compositions with x = 0.10 and 0.33, containing simultaneously paramagnetic Mn(4+), Ni(3+) and Ni(2+) ions and diamagnetic Co(3+) ions. The benefit of using NMR with ultrafast spinning rates is demonstrated for the end composition LiNi0.5Mn0.5O2 having only paramagnetic Ni(2+) and Mn(2+) ions. The local structure of Li is quantified in respect of the number of Ni(2+) and Mn(4+) neighbors. It has been demonstrated that Ni(2+) and Mn(4+) are non-randomly distributed around Li and their distribution depends on the method of synthesis. The extent of local cationic order and its effect on the electrochemical properties of LiNi0.5Mn0.5O2 are discussed.

  4. Using PR Tools to Boost Recruitment.

    ERIC Educational Resources Information Center

    Rabbino, Irma L.

    1979-01-01

    Public relations and admissions are shown to be related. It is not necessary to use exotic PR tools to recruit students. Some suggestions include: the magic of marketing; national, local and hometown media; publications; filmstrips or cassettes; fairs and festivals; public service; and logo buttons, decals, etc. (MLW)

  5. Experimental investigation of the Cd-Pr phase diagram.

    PubMed

    Reichmann, Thomas L; Effenberger, Herta S; Ipser, Herbert

    2014-01-01

    The complete Cd-Pr equilibrium phase diagram was investigated with a combination of powder-XRD, SEM and DTA. All intermetallic compounds within this system, already reported in literature, could be confirmed: CdPr, Cd2Pr, Cd3Pr, Cd45Pr11, Cd58Pr13, Cd6Pr and Cd11Pr. The corresponding phase boundaries were determined at distinct temperatures. The homogeneity range of the high-temperature allotropic modification of Pr could be determined precisely and a limited solubility of 22.1 at.% Cd was derived. Additionally, single-crystal X-ray diffraction was employed to investigate structural details of Cd2Pr; it is isotypic to the AlB2-type structure with a z value of the Cd site of 0.5. DTA results of alloys located in the adjacent two-phase fields of Cd2Pr suggested a phase transformation between 893 and 930°C. For the phase Cd3Pr it was found that the lattice parameter a changes linearly with increasing Cd content, following Vegard's rule. The corresponding defect mechanism could be evaluated from structural data collected with single-crystal XRD. Introduction of a significant amount of vacancies on the Pr site and the reduction in symmetry of one Cd position (8c to 32f) resulted in a noticeable decrease of all R-values.

  6. Experimental Investigation of the Cd-Pr Phase Diagram

    PubMed Central

    Reichmann, Thomas L.; Effenberger, Herta S.; Ipser, Herbert

    2014-01-01

    The complete Cd-Pr equilibrium phase diagram was investigated with a combination of powder-XRD, SEM and DTA. All intermetallic compounds within this system, already reported in literature, could be confirmed: CdPr, Cd2Pr, Cd3Pr, Cd45Pr11, Cd58Pr13, Cd6Pr and Cd11Pr. The corresponding phase boundaries were determined at distinct temperatures. The homogeneity range of the high-temperature allotropic modification of Pr could be determined precisely and a limited solubility of 22.1 at.% Cd was derived. Additionally, single-crystal X-ray diffraction was employed to investigate structural details of Cd2Pr; it is isotypic to the AlB2-type structure with a z value of the Cd site of 0.5. DTA results of alloys located in the adjacent two-phase fields of Cd2Pr suggested a phase transformation between 893 and 930°C. For the phase Cd3Pr it was found that the lattice parameter a changes linearly with increasing Cd content, following Vegard’s rule. The corresponding defect mechanism could be evaluated from structural data collected with single-crystal XRD. Introduction of a significant amount of vacancies on the Pr site and the reduction in symmetry of one Cd position (8c to 32f) resulted in a noticeable decrease of all R-values. PMID:24718502

  7. Experimental investigation of the Cd-Pr phase diagram.

    PubMed

    Reichmann, Thomas L; Effenberger, Herta S; Ipser, Herbert

    2014-01-01

    The complete Cd-Pr equilibrium phase diagram was investigated with a combination of powder-XRD, SEM and DTA. All intermetallic compounds within this system, already reported in literature, could be confirmed: CdPr, Cd2Pr, Cd3Pr, Cd45Pr11, Cd58Pr13, Cd6Pr and Cd11Pr. The corresponding phase boundaries were determined at distinct temperatures. The homogeneity range of the high-temperature allotropic modification of Pr could be determined precisely and a limited solubility of 22.1 at.% Cd was derived. Additionally, single-crystal X-ray diffraction was employed to investigate structural details of Cd2Pr; it is isotypic to the AlB2-type structure with a z value of the Cd site of 0.5. DTA results of alloys located in the adjacent two-phase fields of Cd2Pr suggested a phase transformation between 893 and 930°C. For the phase Cd3Pr it was found that the lattice parameter a changes linearly with increasing Cd content, following Vegard's rule. The corresponding defect mechanism could be evaluated from structural data collected with single-crystal XRD. Introduction of a significant amount of vacancies on the Pr site and the reduction in symmetry of one Cd position (8c to 32f) resulted in a noticeable decrease of all R-values. PMID:24718502

  8. Isolation and characterization of Pr@C{sup 82} and Pr{sup 2}@C{sup 80}

    SciTech Connect

    Ding, J.; Yang, S.

    1996-11-13

    Pr@C{sup 82} and Pr{sup 2}@C{sup 80} have been isolated with a purity of >99.0% by an efficient solvent extraction procedure, followed by HPLC separation. UV-VIS-NIR spectra of the metallofullerenes were measured in the wavelength range from 300 to 2100 nm. The X-ray photoelectron spectra of Pr@C{sup 82} and Pr{sup 2}@C{sup 80} suggest that the Pr atoms inside the carbon cages all exist in a cationic form represented by Pr{sup 3+}. 32 refs., 5 figs.

  9. Electron Paramagnetic Resonance Study of Pr

    SciTech Connect

    Tezuka, Keitaro; Hinatsu, Yukio

    2001-01-01

    Electron paramagnetic resonance (EPR) spectra of tetravalent praseodymium ions doped in the cubic perovskite compound BaHfO{sub 3} have been measured at 4.2 K. A very large hyperfine interaction with the {sup 141}Pr nucleus was observed in the spectrum of Pr{sup 4+}/ BaHfO{sub 3}. The results were analyzed based on the weak field approximation, and the g value (|g|=0.619) and a hyperfine coupling constant (A=0.0589 cm{sup {minus}1}) were obtained. The measured g value is much smaller than |-10/7|, which indicates that the crystal field effect on the behavior of a 4f electron is large. These g and A values were compared with the EPR results for other f{sup 1} ions in an octahedral crystal field.

  10. The structure, thermal expansion and phase transition properties of Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12} (x = 0, 1.0, 2.0) solid solutions

    SciTech Connect

    Liu, X.Z.; Hao, L.J.; Wu, M.M.; Ma, X.B.; Chen, D.F.; Liu, Y.T.

    2015-10-15

    Graphical abstract: A polymorph with Gd{sub 2}Mo{sub 3}O{sub 12}-type structure (space group: Pba2) for negative thermal expansion material Ho{sub 2}Mo{sub 3}O{sub 12} is observed above 700 °C, this polymorphism could be effectively supressed by W-substiution for Mo, the give the temperature dependence of Pba2 phase contents for Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12} (x = 0.0, 1.0, 2.0). - Highlights: • The solid solution Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12} was investigated by in situ X-ray diffraction. • It is found that the substitution slightly influence thermal expansion property. • A polymorph of Ho{sub 2}Mo{sub 3}O{sub 12} with Pba2 space group was observed above 700 °C. • The W-substitution for Mo effectively suppresses this transformation. - Abstract: Three solid solutions of Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12}(x = 0, 1.0, 2.0) were prepared by solid state reaction method, the temperature dependent in-situ X-ray diffraction and thermal analysis were performed to investigate their structure and thermal expansion. All samples have orthorhombic structure(space group Pbcn# 60) with negative thermal expansion at the room temperature. the substitution of W for Mo enlarges the lattice constant and slightly influences the negative thermal expansion. An irreversible phase transformation to the Pba2 phase(Tb{sub 2}Mo{sub 3}O{sub 12} structure) was observed at high temperature for Mo-rich samples. This ploymorphism could be effectively suppressed by the W-substitution for Mo, this phenomenon could be explained by the lower electronegativity of W{sup 6+} than Mo{sup 6+}.

  11. S1PR1 Tyr143 phosphorylation downregulates endothelial cell surface S1PR1 expression and responsiveness

    PubMed Central

    Chavez, Alejandra; Schmidt, Tracy Thennes; Yazbeck, Pascal; Rajput, Charu; Desai, Bhushan; Sukriti, Sukriti; Giantsos-Adams, Kristina; Knezevic, Nebojsa; Malik, Asrar B.; Mehta, Dolly

    2015-01-01

    ABSTRACT Activation of sphingosine-1-phosphate receptor 1 (S1PR1) plays a key role in repairing endothelial barrier function. We addressed the role of phosphorylation of the three intracellular tyrosine residues of S1PR1 in endothelial cells in regulating the receptor responsiveness and endothelial barrier function regulated by sphingosine 1-phosphate (S1P)-mediated activation of S1PR1. We demonstrated that phosphorylation of only Y143 site was required for S1PR1 internalization in response to S1P. Maximal S1PR1 internalization was seen in 20 min but S1PR1 returned to the cell surface within 1 h accompanied by Y143-dephosphorylation. Cell surface S1PR1 loss paralleled defective endothelial barrier enhancement induced by S1P. Expression of phospho-defective (Y143F) or phospho-mimicking (Y143D) mutants, respectively, failed to internalize or showed unusually high receptor internalization, consistent with the requirement of Y143 in regulating cell surface S1PR1 expression. Phosphorylation of the five S1PR1 C-terminal serine residues did not affect the role of Y143 phosphorylation in signaling S1PR1 internalization. Thus, rapid reduction of endothelial cell surface expression of S1PR1 subsequent to Y143 phosphorylation is a crucial mechanism of modulating S1PR1 signaling, and hence the endothelial barrier repair function of S1P. PMID:25588843

  12. Localization of electrons due to orbitally ordered bi-stripes in the bilayer manganite La(2-2x)Sr(1+2x)Mn2O7 (x ~ 0.59).

    PubMed

    Sun, Z; Wang, Q; Fedorov, A V; Zheng, H; Mitchell, J F; Dessau, D S

    2011-07-19

    Electronic phases with stripe patterns have been intensively investigated for their vital roles in unique properties of correlated electronic materials. How these real-space patterns affect the conductivity and other properties of materials (which are usually described in momentum space) is one of the major challenges of modern condensed matter physics. By studying the electronic structure of La(2-2x)Sr(1+2x)Mn(2)O(7) (x ∼ 0.59) and in combination with earlier scattering measurements, we demonstrate the variation of electronic properties accompanying the melting of so-called bi-stripes in this material. The static bi-stripes can strongly localize the electrons in the insulating phase above T(c) ∼ 160 K, while the fraction of mobile electrons grows, coexisting with a significant portion of localized electrons when the static bi-stripes melt below T(c). The presence of localized electrons below T(c) suggests that the melting bi-stripes exist as a disordered or fluctuating counterpart. From static to melting, the bi-stripes act as an atomic-scale electronic valve, leading to a "colossal" metal-insulator transition in this material.

  13. Crystal structure and physical properties of microwave sintered Sr1-xLaxFe12-xCuxO19 (x=0-0.5) ferrites for LTCC applications

    NASA Astrophysics Data System (ADS)

    Peng, Long; Li, Lezhong; Zhong, Xiaoxi; Wang, Rui; Tu, Xiaoqiang

    2016-08-01

    The Sr1-xLaxFe12-xCuxO19 (x=0-0.5) ferrites for use in low temperature co-fired ceramics (LTCC) technology were prepared by improved solid phase method. Dependence of their crystal structure, magnetic, electrical, and dielectric properties on La-Cu substitution amount were investigated. Pure M-type phase is obtained for the ferrites with La-Cu substitution amount x≤0.3. With x further increasing to 0.5, the multiphase structure is formed, where the M-type phase coexists with the LaFeO3 phase and Sr2FeO4-x phase. In single M-type phase region with x≤0.3, the varied magnetic properties can be well explained considering the occupancy effects of La3+ and Cu2+ ions in magnetoplumbite structure. Their electrical transport behavior is found to be correlated with La-Cu substitution amount. Single metal-semiconductor (M-S) transition is clearly observed in the ferrites with a high doping amount as x=0.3. The polarization behavior from 1 kHz to 10 MHz follows the charge polarization mechanism, and the temperature dependence of real permittivity (ε‧-T curves) and dielectric loss (tgδ-T curves) strongly suggests the complicated multiparticle polarization and relaxation.

  14. Site preference and vibrational properties of R{sub 3}T{sub 4+x}Al{sub 12-x} (R=Y, Ce, Gd, U, Th; T=Fe, Ru)

    SciTech Connect

    Chen Yi; Shen Jiang; Chen Nanxian

    2010-03-15

    The crystal structures and phase stability of the ternary alloys R{sub 3}T{sub 4+x}Al{sub 12-x} (R=Y, Ce, Gd, U, Th; T=Fe, Ru) have been investigated using the interatomic potentials obtained by the lattice inversion method. These compounds crystallize in the hexagonal Gd{sub 3}Ru{sub 4}Al{sub 12}-type structure and the calculated lattice constants correspond well with the experiments. Among the four different kinds of Al sites in the structure, the most preferential sites for Fe atoms or Ru atoms are 6h sites. The properties related to lattice vibration, such as the phonon density of states (DOS) and Debye temperature of R{sub 3}Fe{sub 4}Al{sub 12,} have been evaluated. A qualitative analysis is carried out with the relevant potentials for the vibrational modes, which makes it possible to predict some thermodynamic properties. - The crystal structure of R{sub 3}T{sub 4}Al{sub 12} could be considered as two kinds of layer stacking up along the hexagonal c axis. Fe and Ru atoms preferentially substitute for Al atoms at 6h site.

  15. Atomic scale studies of La/Sr ordering in colossal magnetoresistant La2-2xSr1+2xMn2O7 single crystals

    SciTech Connect

    Roldan, Manuel A.; Oxley, Mark P.; Li, Qing'an A.; Zheng, Hong; Gray, Kenneth E.; Mitchell, John F.; Pennycook, Stephen J.; Varela, Maria

    2014-09-29

    In this study, it is unclear whether chemical order (or disorder) is in any way connected to double exchange, electronic phase separation, or charge ordering (CO) in manganites. In this work, we carry out an atomic resolution study of the colossal magnetoresistant manganite La2–2xSr1+2xMn2O7 (LSMO). We combine aberration-corrected electron microscopy and spectroscopy with spectroscopic image simulations, to analyze cation ordering at the atomic scale in real space in a number of LSMO single crystals. We compare three different compositions within the phase diagram: a ferromagnetic metallic material (x=0.36), an insulating, antiferromagnetic charge ordered (AF-CO) compound (x=0.5), which also exhibits orbital ordering, and an additional AF sample (x=0.56). Detailed image simulations are essential to accurately quantify the degree of chemical ordering of these samples. We find a significant degree of long-range chemical ordering in all cases, which increases in the AF-CO range. However, the degree of ordering is never complete nor can it explain the strongly correlated underlying ordering phenomena. Our results show that chemical ordering over distinct crystallographic sites is not needed for electronic ordering phenomena to appear in manganites, and cannot by itself explain the complex electronic behavior of LSMO.

  16. Atomic scale studies of La/Sr ordering in colossal magnetoresistant La2-2xSr1+2xMn2O7 single crystals

    DOE PAGES

    Roldan, Manuel A.; Oxley, Mark P.; Li, Qing'an A.; Zheng, Hong; Gray, Kenneth E.; Mitchell, John F.; Pennycook, Stephen J.; Varela, Maria

    2014-09-29

    In this study, it is unclear whether chemical order (or disorder) is in any way connected to double exchange, electronic phase separation, or charge ordering (CO) in manganites. In this work, we carry out an atomic resolution study of the colossal magnetoresistant manganite La2–2xSr1+2xMn2O7 (LSMO). We combine aberration-corrected electron microscopy and spectroscopy with spectroscopic image simulations, to analyze cation ordering at the atomic scale in real space in a number of LSMO single crystals. We compare three different compositions within the phase diagram: a ferromagnetic metallic material (x=0.36), an insulating, antiferromagnetic charge ordered (AF-CO) compound (x=0.5), which also exhibits orbitalmore » ordering, and an additional AF sample (x=0.56). Detailed image simulations are essential to accurately quantify the degree of chemical ordering of these samples. We find a significant degree of long-range chemical ordering in all cases, which increases in the AF-CO range. However, the degree of ordering is never complete nor can it explain the strongly correlated underlying ordering phenomena. Our results show that chemical ordering over distinct crystallographic sites is not needed for electronic ordering phenomena to appear in manganites, and cannot by itself explain the complex electronic behavior of LSMO.« less

  17. Thermal and structural analysis of the LBL 10 x 40 cm long pulse accelerator and the 12 x 48 cm common long pulse accelerator for TFTR, doublet III-D, and MFTF-B

    SciTech Connect

    Wells, R.P.

    1985-11-01

    Stress and deflection of the grid rails of the existing, Lawrence Berkeley Laboratory (LBL) designed, 10 x 40 cm Long Pulse (neutral beam) Accelerator (40LPA) and the expanded 12 x 48 cm version, Common Long Pulse Source (CLPS), have been computed for a series of assumed heat load distributions. The combined stress from self-constraint of thermal expansion and rail holder reaction forces has been calculated. A simplification of the gradient grid rail holder was analyzed and was found to work as well or better than the original 40LPA design under the most probable operating conditions. Heat flux non-uniformity over the rail surface for both accelerator designs was estimated from 40LPA grid calorimetry data for arc and beam extraction operation. The extrapolated total heat load per rail for the CLPS was less than the 1.2 kW value used in this analysis. Under worst case assumptions, the maximum equivalent stress in any of the molybdenum grid rails was less than 20% of yield. For the anticipated heat load distribution on the gradient grid, the predicted deflection of the grid rail meets the 0.0457 mm position tolerance except under extremely non-uniform heat loads.

  18. Electrical and electrochemical properties of molten salt-synthesized Li4Ti5-xSnxO12 (x=0.0, 0.05 and 0.1) as anodes for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Sharmila, S.; Senthilkumar, B.; Nithya, V. D.; Vediappan, Kumaran; Lee, Chang Woo; Selvan, R. Kalai

    2013-11-01

    Submicron-sized polyhedral Li4Ti5-xSnxO12 (x=0.0, 0.05, and 0.1) materials were successfully prepared by a single-step molten salt method. The structural, morphological, transport and electrochemical properties of the Li4Ti5-xSnxO12 were studied. X-ray diffraction patterns showed the formation of a cubic structure with a lattice constant of 8.31 Å, and the addition of dopants follows Vegard's law. Furthermore, FT-IR spectra revealed symmetric stretching vibrations of octahedral groups of MO6 lattice in Li4Ti5O12. The formation of polyhedral submicron Li4Ti5-xSnxO12 particles was inferred from FE-SEM images, and a particle size reduction was observed for Sn-doped Li4Ti5O12. The chemical composition of Ti, O and Sn was verified by EDAX. The DC electrical conductivity was found to increase with increasing temperature, and a maximum conductivity of 8.96×10-6 S cm-1 was observed at 200 °C for Li4Ti5O12. The galvanostatic charge-discharge behavior indicates that the Sn-doped Li4Ti5O12 could be used as an anode for Li-ion batteries due to its enhanced electrochemical properties.

  19. Molten salt synthesis and characterization of Li4Ti5-xMnxO12 (x = 0.0, 0.05 and 0.1) as anodes for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Nithya, V. D.; Kalai Selvan, R.; Vediappan, Kumaran; Sharmila, S.; Lee, Chang Woo

    2012-11-01

    Sub-micrometer sized Li4Ti5-xMnxO12 (x = 0.0, 0.05 and 0.1) particles were synthesized by a single step molten salt method using LiCl-KCl as a flux. The synthesized material was structurally characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectra. The XRD analysis revealed the particles to be highly crystalline and have a face-centered cubic spinel structure. The presence of possible functional group was confirmed through FTIR analysis. The FE-SEM images showed the particles to be polyhedral in shape with uniform size distribution. It was also revealed that there was a particle size reduction with the effect of Mn4+ dopant ions. The electrochemical studies performed using cyclic voltammogram (CV), charge-discharge, and electrochemical impedance analysis (EIS) indicate that Li4Ti4.9Mn0.1O4 possesses a better discharge capacity (305 mAh/g), cycling stability, and charge carrier conductivity than both Li4Ti4.95Mn0.05O12 (265 mAh/g) and Li4Ti5O12 (240 mAh/g). The cycling stability reveals that the acceptable capacity fading was observed even after 20th cycle. The results of electrochemical studies infer that Li4Ti4.9Mn0.1O4 could be utilized as a suitable anode material for Li-ion batteries.

  20. Synthesis and proposed crystal structure of a disordered cadmium arsenate apatite Cd5(AsO4)3Cl(1-2x-y)O(x)[symbol: see text](x)OH(y).

    PubMed

    Johnson, Christopher D; Feldmann, Jorg; Macphee, Donald E; Worrall, Fred; Skakle, Janet M S

    2004-11-01

    During a study into the synthesis of minerals composed of mining wastes aimed at improving their immobilisation, a cadmium arsenate apatite has been prepared by hydrothermal methods. The structure of this apatite was analysed by single crystal X-ray diffraction, and was found to consist of a standard apatite framework based on Cd(5)(AsO(4))(3)X, where X represents an anion resident on the (0,0,0.25) site. The framework is hexagonal with the space group P6(3)/m(no 176), a= 9.9709(8), c= 6.4916(4)[Angstrom]. The X ion site is predominantly occupied by Cl(-) ions; however due to significant shortening of the c axis exhibited by all cadmium containing apatite phases, a pure chlorapatite is not possible without a significant cation deficiency. No evidence of the necessary deficiency was found in the crystal structure. For larger bromo- and iodo-apatites significant modulations along the c-axis are required to accommodate the halide. This paper examines a number of compensation mechanisms and proposes that a minor disorder of chloride, oxide and hydroxide located on the X ion site provides the required charge compensation mechanism. This is contrary to previous complex modulations proposed in the literature. The proposed chemical formula is Cd(5)(AsO(4))(3)Cl(1-2x-y)O(x)[symbol:see text](x)OH(y) where [symbol: see text] represents a vacancy.

  1. Relation between the Cu(1)-O(4) distance and Tc in Y1-2xCaxThxBa2Cu3O7-δ: Raman scattering and calculation of the electron-phonon interaction

    NASA Astrophysics Data System (ADS)

    Andersson, M.; Börjesson, L.; Jarlborg, T.; Phuong, H. V.; Rapp, Ö.

    1992-09-01

    The strong depression of Tc with Ca-Th substitution in Y1-2xCaxThxBa2Cu3O7-δ has been investigated in a model calculation of the electronic and phononic contributions from the apex oxygen, O(4), on the electron-phonon interaction, λ. The shift with Ca-Th substitution of the characteristic O(4) vibrational mode was measured by Raman scattering. The electronic part η of λ has been calculated at several distances between chain Cu(1) and O(4) in the region of the observed variation with x. η was found to depend strongly on this distance. The results show a small increase with x of the O(4) frequency and a strong decrease of η. Both these factors thus contribute to a decrease of λ. We therefore find evidence that a decreasing electron-phonon interaction is associated with the depression of Tc in Ca-Th substituted YBa2Cu3O7-δ.

  2. Atomic scale studies of La/Sr ordering in colossal magnetoresistant La(2-2x)Sr(1+2x)Mn2O7 single crystals.

    PubMed

    Roldan, Manuel A; Oxley, Mark P; Li, Qing'an; Zheng, Hong; Gray, K E; Mitchell, J F; Pennycook, Stephen J; Varela, María

    2014-12-01

    To date, it is unclear whether chemical order (or disorder) is in any way connected to double exchange, electronic phase separation, or charge ordering (CO) in manganites. In this work, we carry out an atomic resolution study of the colossal magnetoresistant manganite La(2-2x)Sr(1+2x)Mn2O7 (LSMO). We combine aberration-corrected electron microscopy and spectroscopy with spectroscopic image simulations, to analyze cation ordering at the atomic scale in real space in a number of LSMO single crystals. We compare three different compositions within the phase diagram: a ferromagnetic metallic material (x=0.36), an insulating, antiferromagnetic charge ordered (AF-CO) compound (x=0.5), which also exhibits orbital ordering, and an additional AF sample (x=0.56). Detailed image simulations are essential to accurately quantify the degree of chemical ordering of these samples. We find a significant degree of long-range chemical ordering in all cases, which increases in the AF-CO range. However, the degree of ordering is never complete nor can it explain the strongly correlated underlying ordering phenomena. Our results show that chemical ordering over distinct crystallographic sites is not needed for electronic ordering phenomena to appear in manganites, and cannot by itself explain the complex electronic behavior of LSMO.

  3. Charge/orbital ordered phases of La{sub 2-2x}Sr{sub 1+2x}Mn{sub 2}O{sub 7-{delta}}.

    SciTech Connect

    Zheng, H.; Li, Q.; Gray, K. E.; Mitchell, J. F.; Materials Science Division

    2008-01-01

    Our studies have significantly modified the conventionally held view of the phase diagram of La{sub 2-2x}Sr{sub 1+2x}Mn{sub 2}O{sub 7-{delta}} for two compositions exhibiting charge (and orbital) order (CO), i.e., at hole-doping levels, h = x-{delta}, of {approx}0.5 and {approx}0.6. These CO states are stable over very narrow doping ranges ({Delta}h {+-} 0.005) at the lowest temperatures, but those ranges increase at higher temperatures (to {Delta}h {+-} 0.02) in a manner consistent with simple entropy considerations. Such narrow ranges dictate the crucial need for crystal homogeneity. Attesting to such homogeneity is a conductivity ratio of >10{sup 10} upon crossing the first-order phase boundary from CO at h = 0.60 to A-type antiferromagnetic (AAFM) at h-0.59 or h-0.61 plus two findings that were missed in the existing literature: that these CO phases are the ground state at the lowest temperatures, and for h-0.5, that coexistence of the CO and AAFM phase is absent at any temperature.

  4. PrPC from stem cells to cancer

    PubMed Central

    Martin-Lannerée, Séverine; Hirsch, Théo Z.; Hernandez-Rapp, Julia; Halliez, Sophie; Vilotte, Jean-Luc; Launay, Jean-Marie; Mouillet-Richard, Sophie

    2014-01-01

    The cellular prion protein PrPC was initially discovered as the normal counterpart of the pathological scrapie prion protein PrPSc, the main component of the infectious agent of Transmissible Spongiform Encephalopathies. While clues as to the physiological function of this ubiquitous protein were greatly anticipated from the development of knockout animals, PrP-null mice turned out to be viable and to develop without major phenotypic abnormalities. Notwithstanding, the discovery that hematopoietic stem cells from PrP-null mice have impaired long-term repopulating potential has set the stage for investigating into the role of PrPC in stem cell biology. A wealth of data have now exemplified that PrPC is expressed in distinct types of stem cells and regulates their self-renewal as well as their differentiation potential. A role for PrPC in the fate restriction of embryonic stem cells has further been proposed. Paralleling these observations, an overexpression of PrPC has been documented in various types of tumors. In line with the contribution of PrPC to stemness and to the proliferation of cancer cells, PrPC was recently found to be enriched in subpopulations of tumor-initiating cells. In the present review, we summarize the current knowledge of the role played by PrPC in stem cell biology and discuss how the subversion of its function may contribute to cancer progression. PMID:25364760

  5. Modulation of Glycosaminoglycans Affects PrPSc Metabolism but Does Not Block PrPSc Uptake

    PubMed Central

    Wolf, Hanna; Graßmann, Andrea; Bester, Romina; Hossinger, André; Möhl, Christoph; Paulsen, Lydia; Groschup, Martin H.; Schätzl, Hermann

    2015-01-01

    ABSTRACT Mammalian prions are unconventional infectious agents composed primarily of the misfolded aggregated host prion protein PrP, termed PrPSc. Prions propagate by the recruitment and conformational conversion of cellular prion protein into abnormal prion aggregates on the cell surface or along the endocytic pathway. Cellular glycosaminoglycans have been implicated as the first attachment sites for prions and cofactors for cellular prion replication. Glycosaminoglycan mimetics and obstruction of glycosaminoglycan sulfation affect prion replication, but the inhibitory effects on different strains and different stages of the cell infection have not been thoroughly addressed. We examined the effects of a glycosaminoglycan mimetic and undersulfation on cellular prion protein metabolism, prion uptake, and the establishment of productive infections in L929 cells by two mouse-adapted prion strains. Surprisingly, both treatments reduced endogenous sulfated glycosaminoglycans but had divergent effects on cellular PrP levels. Chemical or genetic manipulation of glycosaminoglycans did not prevent PrPSc uptake, arguing against their roles as essential prion attachment sites. However, both treatments effectively antagonized de novo prion infection independently of the prion strain and reduced PrPSc formation in chronically infected cells. Our results demonstrate that sulfated glycosaminoglycans are dispensable for prion internalization but play a pivotal role in persistently maintained PrPSc formation independent of the prion strain. IMPORTANCE Recently, glycosaminoglycans (GAGs) became the focus of neurodegenerative disease research as general attachment sites for cell invasion by pathogenic protein aggregates. GAGs influence amyloid formation in vitro. GAGs are also found in intra- and extracellular amyloid deposits. In light of the essential role GAGs play in proteinopathies, understanding the effects of GAGs on protein aggregation and aggregate dissemination is crucial

  6. Photoelectron spectrum of PrO-

    NASA Astrophysics Data System (ADS)

    Kafader, Jared O.; Ray, Manisha; Jarrold, Caroline Chick

    2015-08-01

    The photoelectron (PE) spectrum of PrO- exhibits a short 835 ± 20 cm-1 vibrational progression of doublets (210 ± 30 cm-1 splitting) assigned to transitions from the 4f2 [3H4] σ6s2 Ω = 4 anion ground state to the 4f2 [3H4] σ6s Ω = 3.5 and 4.5 neutral states. This assignment is analogous to that of the recently reported PE spectrum of CeO-, though the 82 cm-1 splitting between the 4f [2F2.5] σ6s Ω = 2 and Ω = 3 CeO neutral states could not be resolved [Ray et al., J. Chem. Phys. 142, 064305 (2015)]. The origin of the transition to the Ω = 3.5 neutral ground state is 0.96 ± 0.01 eV, which is the adiabatic electron affinity of PrO. Density functional theory calculations on the anion and neutral molecules support the assignment. The appearance of multiple, irregularly spaced and low-intensity features observed ca. 1 eV above the ground state cannot be reconciled with low-lying electronic states of PrO that are accessible via one-electron detachment. However, neutral states correlated with the 4f2 [3H4] 5d superconfiguration are predicted to be approximately 1 eV above the 4f2 [3H4] σ6s Ω = 3.5 neutral ground state, leading to the assignment of these features to shake-up transitions to the excited neutral states. Based on tentative hot band transition assignments, the term energy of the previously unobserved 4f2 [3H4] σ6s Ω = 2.5 neutral state is determined to be 1840 ± 110 cm-1.

  7. Effect of low ionic strength on anti-Pr reactions.

    PubMed

    Leo, A; Kreft, H; Hack, H; Roelcke, D

    1996-01-01

    The effect of low ionic strength (LIS) on 28 anti-Pr, 20 anti-I and 20 anti-i cold agglutinins was investigated. The reaction of the anti-Pr CAs varies markedly. In most cases LIS has an enhancing effect. In some cases the thermal amplitude was widened so far that the reaction at 37 degrees C under LIS was stronger than at 0 degree C in PBS. With regard to the anti-Pr subspecificities anti Pr1, -Pr2 and -Pr3 or to the distinction of the immunodominant NeuNAc group (alpha a2,6- or alpha 2,3-bond) a correlation between these characteristics and the reaction in LIS could not be identified. The anti-I are not influenced by LISS, anti-i in a few cases. The reason for the variable reaction of the anti-Pr remains unclear. To further elucidate the LISS effect on anti-Pr, the contribution of the antibody structure should be regarded, but data for the use of H- and L-chain genes in anti-Pr are sparse. For compatibility testing in the routine laboratory, LISS-sensitive anti-Pr may play a role in disturbing the screening for RBC antibodies.

  8. The PR in PN for Education Associations. PR Bookshelf, No. 3.

    ERIC Educational Resources Information Center

    National Education Association, Washington, DC.

    This booklet presents suggestions and guidelines for the effective use of public relations (PR) techniques during professional negotiations (PN) among teachers, administrators, and boards of education. Introductory sections present the National Education Association (NEA) position regarding professional negotiation and grievance procedures and…

  9. Infrared spectroscopy of [XFeC24H12]+ (X = C5H5, C5(CH3)5) complexes in the gas phase: experimental and computational studies of astrophysical interest.

    PubMed

    Simon, Aude; Joblin, Christine; Polfer, Nick; Oomens, Jos

    2008-09-18

    We report the first experimental mid-infrared (700-1600 cm (-1)) multiple-photon dissociation (IRMPD) spectra of [XFeC 24H 12] (+) (X = C 5H 5 or Cp, C 5(CH 3) 5 or Cp*) complexes in the gas phase obtained using the free electron laser for infrared experiments. The experimental results are complemented with theoretical infrared (IR) absorption spectra calculated with methods based on density functional theory. The isomers in which the XFe unit is coordinated to an outer ring of C 24H 12 (+) (Out isomers) were calculated to be the most stable ones. From the comparison between the experimental and calculated spectra, we could derive that, (i) for [CpFeC 24H 12] (+) complexes, the (1)A Out isomer appears to be the best candidate to be formed in the experiment but the presence of the (1)A In higher energy isomer in minor abundance is also plausible; and (ii) for [Cp*FeC 24H 12] (+) complexes, the three calculated Out isomers of similar energy are likely to be present simultaneously, in qualitative agreement with the observed dissociation patterns. This study also emphasizes the threshold effect in the IRMPD spectrum below which IR bands cannot be observed and evidence strong mode coupling effects in the [XFeC 24H 12] (+) species. The effect of the coordination of Fe in weakening the bands of C 24H 12 (+) in the 1000-1600 cm (-1) region is confirmed, which is of interest to search for such complexes in interstellar environments.

  10. Synthesis, Average Structure, and Magnetic Properties of Oxygen Deficient Perovskites (Ba 2-3 xBi 3 x-1 )(Fe 2 xBi 1-2 x)O 2+3/2 x

    NASA Astrophysics Data System (ADS)

    Boullay, Ph.; Hervieu, M.; Nguyen, N.; Raveau, B.

    1999-10-01

    A new family of oxygen deficient perovskite [Ba2-3xBi3x-1] [Fe2xBi1-2x]O2+3x/2 has been synthesized for 1/3≤x≤1/2. The average structure of these phases is determined using a combination of X-ray, neutron powder diffraction, and electron diffraction. The compounds exhibit a cubic subcell (a=ap) for x≤0.43 and a tetragonal subcell (a≈c≈ap) for 0.43

  11. Effect of La-Co substitution on the crystal structure and magnetic properties of hot press sintered Sr1-xLaxFe12-xCoxO19 (x=0-0.5) ferrites for use in LTCC technology

    NASA Astrophysics Data System (ADS)

    Peng, Long; Li, Lezhong; Wang, Rui; Hu, Yun; Tu, Xiaoqiang

    2015-10-01

    The La3+ and Co2+ substituted Sr1-xLaxFe12-xCoxO19 (x=0-0.5) ferrites with Bi2O3 additive were prepared by hot press sintering method at a low sintering temperature of 870 °C compatible with LTCC (low temperature co-fired ceramics) systems, and their crystal structure and magnetic properties were mainly investigated. The results show that the pure M-type crystal phase is successfully obtained for the ferrites with La-Co substitution amount x not higher than 0.3. When the substitution amount further increases to 0.4 and 0.5, the α-Fe2O3 phase and La2O3 phase are found to coexist with the M-type phase, thus the multiphase structure is formed. Besides, the saturation magnetization Ms, intrinsic coercivity Hci, and Curie temperature TC of the ferrites are strongly correlated with the La-Co substitution amount. Enhanced Ms and Hci are obtained when the substitution amount varies from 0.2 to 0.4, which can exceed 3600 Gs and 4000 Oe, respectively. However, the TC decreases rapidly when the substitution amount exceeds 0.3, and a value under 410 °C is observed. It is suggested that the La3+-Co2+ ions can partially substitute the Sr2+-Fe3+ ions for the hot press sintered ferrites at low sintering temperatures, leading to improved Ms and Hci for use in microwave LTCC ferrite devices.

  12. Prion protein (PrP) gene-knockout cell lines: insight into functions of the PrP

    PubMed Central

    Sakudo, Akikazu; Onodera, Takashi

    2015-01-01

    Elucidation of prion protein (PrP) functions is crucial to fully understand prion diseases. A major approach to studying PrP functions is the use of PrP gene-knockout (Prnp−/−) mice. So far, six types of Prnp−/− mice have been generated, demonstrating the promiscuous functions of PrP. Recently, other PrP family members, such as Doppel and Shadoo, have been found. However, information obtained from comparative studies of structural and functional analyses of these PrP family proteins do not fully reveal PrP functions. Recently, varieties of Prnp−/− cell lines established from Prnp−/− mice have contributed to the analysis of PrP functions. In this mini-review, we focus on Prnp−/− cell lines and summarize currently available Prnp−/− cell lines and their characterizations. In addition, we introduce the recent advances in the methodology of cell line generation with knockout or knockdown of the PrP gene. We also discuss how these cell lines have provided valuable insights into PrP functions and show future perspectives. PMID:25642423

  13. Salvinorin A analogues PR-37 and PR-38 attenuate compound 48/80-induced itch responses in mice

    PubMed Central

    Salaga, M; Polepally, P R; Zielinska, M; Marynowski, M; Fabisiak, A; Murawska, N; Sobczak, K; Sacharczuk, M; Do Rego, J C; Roth, B L; Zjawiony, J K; Fichna, J

    2015-01-01

    Background and Purpose The opioid system plays a crucial role in several physiological processes in the CNS and in the periphery. It has also been shown that selective opioid receptor agonists exert potent inhibitory action on pruritus and pain. In this study we examined whether two analogues of Salvinorin A, PR-37 and PR-38, exhibit antipruritic properties in mice. Experimental Approach To examine the antiscratch effect of PR-37 and PR-38 we used a mouse model of compound 48/80-induced pruritus. In order to elucidate the mechanism of action of tested compounds, specific antagonists of opioid and cannabinoid receptors were used. The effect of PR-37 on the CNS was assessed by measuring motor parameters and exploratory behaviours in mice. Key Results PR-37 and PR-38, jnjected s.c., significantly reduced the number of compound 48/80-induced scratching behaviours in mice in a dose- and time-dependent manner. PR-38 was also active when orally administered. The antiscratch activity of PR-37 was blocked by the selective κ opioid receptor antagonist, nor-binaltorphimine, and that of PR-38 by the selective μ opioid receptor antagonist, β-funaltrexamine. Conclusion and Implications In conclusion, a novel framework for the development of new antipruritic drugs derived from salvinorin A has been validated. PMID:26040667

  14. Prion propagation in cells expressing PrP glycosylation mutants.

    PubMed

    Salamat, Muhammad K; Dron, Michel; Chapuis, Jérôme; Langevin, Christelle; Laude, Hubert

    2011-04-01

    Infection by prions involves conversion of a host-encoded cell surface protein (PrP(C)) to a disease-related isoform (PrP(Sc)). PrP(C) carries two glycosylation sites variably occupied by complex N-glycans, which have been suggested by previous studies to influence the susceptibility to these diseases and to determine characteristics of prion strains. We used the Rov cell system, which is susceptible to sheep prions, to generate a series of PrP(C) glycosylation mutants with mutations at one or both attachment sites. We examined their subcellular trafficking and ability to convert into PrP(Sc) and to sustain stable prion propagation in the absence of wild-type PrP. The susceptibility to infection of mutants monoglycosylated at either site differed dramatically depending on the amino acid substitution. Aglycosylated double mutants showed overaccumulation in the Golgi compartment and failed to be infected. Introduction of an ectopic glycosylation site near the N terminus fully restored cell surface expression of PrP but not convertibility into PrP(Sc), while PrP(C) with three glycosylation sites conferred cell permissiveness to infection similarly to the wild type. In contrast, predominantly aglycosylated molecules with nonmutated N-glycosylation sequons, produced in cells expressing glycosylphosphatidylinositol-anchorless PrP(C), were able to form infectious PrP(Sc). Together our findings suggest that glycosylation is important for efficient trafficking of anchored PrP to the cell surface and sustained prion propagation. However, properly trafficked glycosylation mutants were not necessarily prone to conversion, thus making it difficult in such studies to discern whether the amino acid changes or glycan chain removal most influences the permissiveness to prion infection. PMID:21248032

  15. High spin states in /sup 137/Pr

    SciTech Connect

    Xu, N.; Beausang, C.W.; Ma, R.; Paul, E.S.; Piel W.F. Jr.; Fossan, D.B.; Hildingsson, L.

    1989-05-01

    The level structure of the /sup 137/Pr nucleus has been investigated via in-beam ..gamma..-ray spectroscopy using an 81-MeV /sup 122/Sn(/sup 19/F, 4n) reaction. A strongly populated positive-parity band was observed based on a proton orbital with (..pi..,..cap alpha..) = (+, + 1/2); its first backbend, due to the alignment of a pair of h/sub 11/2/ protons, was seen at a rotational frequency (h/2..pi..)..omega.. = 0.34 MeV. Such a high crossing frequency is taken as evidence for a triaxial shape (..gamma../similar to/30/sup 0/) for the ground-state band of /sup 137/Pr. Above the crossing, both signatures (..pi..,..cap alpha..) = +, +- (1/2) were observed up to I/sup ..pi../ = 37/2/sup +/ and 43/2/sup +/ (for ..cap alpha.. = +1/2 and ..cap alpha.. = -1/2), respectively. A negative-parity band, based on an h/sub 11/2/ proton orbital, was also observed showing a blocked h/sub 11/2/ proton crossing frequency of h/2..pi omega.. = 0.44 MeV. In addition, a ..delta..I = 1 band with strong M1 transitions and a small signature splitting was observed, which is believed to be based on the ..pi..h/sub 11/2/x(..nu..h/sub 11/2/)/sup 2/ configuration. The alignment of the h/sub 11/2/ neutron pair drives the nuclear core towards ..gamma.. = -60/sup 0/, namely, the collective oblate shape, while the alignment of the h/sub 11/2/ proton pair drives the nuclear core towards ..gamma.. = 0/sup 0/, the collective prolate shape. These results are consistent with cranked shell model calculations.

  16. Self-reported Recent PrEP Dosing and Drug Detection in an Open Label PrEP Study.

    PubMed

    Amico, K Rivet; Mehrotra, Megha; Avelino-Silva, Vivian I; McMahan, Vanessa; Veloso, Valdilea G; Anderson, Peter; Guanira, Juan; Grant, Robert

    2016-07-01

    Monitoring adherence to pre-exposure prophylaxis (PrEP) is part of the recommended package for PrEP prescribing, yet ongoing concerns about how to do so confidently are exacerbated by gross discrepancies in reported and actual use in clinical trials. We evaluated concordance between reports of recent PrEP dosing collected via neutral interviewing and drug quantitation in the iPrEx open-label extension, where participants (n = 1172) had the choice to receive or not receive PrEP. Self-report of recent dosing (at least one PrEP dose in the past 3-day) was the most common report (84 % of participants), and among these 83 % did have quantifiable levels of drug. The vast majority of those reporting no doses in the past 3-day (16 % of the sample) did not have quantifiable levels of drug (82 %). Predictors of over-report of dosing included younger age and lower educational attainment. Monitoring recent PrEP use through neutral interviewing may be a productive approach for clinicians to consider in implementation of real-world PrEP. Strategies to capture longer term or prevention-effective PrEP use, particularly for younger cohorts, are needed.

  17. 78 FR 47051 - Proposed Collection; Comment Request for Forms 943, 943-PR, 943-A, and 943A-PR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-02

    ..., Employer's Annual Tax Return for Agricultural Employees, 943-PR, Planilla Para La Declarcion Anual De La... . SUPPLEMENTARY INFORMATION: Title: Employer's Annual Tax Return for Agricultural Employees (Form 943),...

  18. High-pressure synthesis and characterization of BiCu{sub 3}(Mn{sub 4−x}Fe{sub x})O{sub 12} (x=0, 1.0, 2.0) complex perovskites

    SciTech Connect

    Kayser, P.; Martínez-Lope, M.J.; Alonso, J.A.; Sánchez-Benítez, J.; Fernández, M.T.

    2013-08-15

    We have studied the series of nominal composition BiCu{sub 3}(Mn{sub 4−x}Fe{sub x})O{sub 12} (x=0, 1.0, 2.0) where Mn is replaced by Fe cations in the ferrimagnetic perovskite BiCu{sub 3}Mn{sub 4}O{sub 12}. These compounds have been prepared from citrate precursors under moderate pressure conditions (3.5 GPa) and 1000 °C in the presence of KClO{sub 4} as oxidizing agent. All the samples have been studied by x-ray and neutron powder diffraction (NPD) at room temperature and 4 K. The crystal structure has been defined in a cubic Im3{sup ¯} (No. 204) space group with a 2a{sub 0}×2a{sub 0}×2a{sub 0} unit-cell. The doubling of the unit-cell occurs due to the ordering of Bi{sup 3+} and Cu{sup 2+} cations over A sites of the AA′{sub 3}B{sub 4}O{sub 12} structure. The A-site accommodates 12-fold coordinated Bi{sup 3+} ions and, at the A′-site, Jahn–Teller Cu{sup 2+} ions form pseudo-square planar units aligned perpendicular to each other. Mn{sup 4+}/Fe{sup 3+} cations randomly occupy the centre of slightly distorted octahedra. These materials have also been characterized by magnetic and magnetotransport measurements. We found that all the samples are ferrimagnetic and show a progressive decrease of T{sub C} as the Fe content increases, since Fe ions disturb the ferromagnetic interactions within the B magnetic sublattice. In fact, the Curie temperature diminishes from T{sub C}=360 K (x=0) to T{sub C}=219 K (x=2). The magnetic structures, studied by low-temperature NPD data, correspond to an antiferromagnetic arrangement of spins at 8c and 6b sites; the ordered moments are in excellent agreement with those obtained from the saturation magnetization at 4 K. A significant magnetoresistant effect is determined for the x=1.0 oxide, with low-field values as high as 5% at 300 K and 1 T. Highlights: • BiCu{sub 3}(Mn{sub 4−x}Fe{sub x})O{sub 12} perovskites have been prepared under high pressure conditions. • They have been characterized by NPD, magnetic and

  19. Dielectric characteristics of fast Li ion conducting garnet-type Li5+2xLa3Nb2-xYxO12 (x = 0.25, 0.5 and 0.75).

    PubMed

    Narayanan, Sumaletha; Baral, Ashok Kumar; Thangadurai, Venkataraman

    2016-06-01

    Here, we report the dielectric characteristics of Li-stuffed garnet-type Li5+2xLa3Nb2-xYxO12 (x = 0.25, 0.5 and 0.75) in the temperature range about -53 to 50 °C using AC impedance spectroscopy. All the investigated Li-stuffed garnet compounds were prepared, under the same condition, using conventional solid-state reaction at elevated temperature in air. The Nyquist plots show mainly bulk contribution to the total Li(+) ion conductivity for Li5.5La3Nb1.75Y0.25O12 (Li5.5-Nb) and Li6La3Nb1.5Y0.5O12 (Li6-Nb), while both bulk and grain-boundary effects are visible in the case of Li6.5La3Nb1.25Y0.75O12 (Li6.5-Nb) phase at ∼-22 °C. Non-Debye relaxation process was observed in the modulus AC impedance plots. The dielectric loss tangent of Li5+2xLa3Nb2-xYxO12 are compared with that of the corresponding Ta analogue, Li5+2xLa3Ta2-xYxO12 and showed a decrease in peak intensity for the Nb-based garnet samples which may be attributed to a slight increase in their Li(+) ion conductivity. The relative dielectric constant values were also found to be higher for the Ta member (>60 for Li5+2xLa3Ta2-xYxO12) than that of the corresponding Nb analogue (∼50 for Li5+2xLa3Nb2-xYxO12) at below room temperature. A long-range order Li(+) ion migration pathway with relaxation time (τ0) 10(-18)-10(-15) s and an activation energy of 0.59-0.40 eV was observed for the investigated Li5+2xLa3Nb2-xYxO12 garnets and is comparable to that of the corresponding Ta-based Li5+2xLa3Ta2-xYxO12 garnets.

  20. Deformed rotational bands in the doubly odd nuclei [sup 134]Pr and [sup 132]Pr

    SciTech Connect

    Hauschild, K.; Wadsworth, R.; Clark, R.M.; Hibbert, I.M. ); Beausang, C.W.; Forbes, S.A.; Nolan, P.J.; Paul, E.S.; Semple, A.T.; Wilson, J.N. ); Gizon, A.; Gizon, J.; Santos, D. ); Simpson, J. )

    1994-08-01

    The nuclei [sup 132,134]Pr have been investigated using the [sup 100]Mo([sup 37]Cl,[ital xn]) reactions at a beam energy of 155 MeV. Gamma rays were detected with the Eurogam array. Analysis of the data has revealed the presence of two new weakly populated decoupled bands in [sup 134]Pr. One of these bands has been linked into the normal-deformed states and is thought to be built on a [pi]([ital h][sub 11/2])[sup 2][direct product][nu]([ital f][sub 7/2],[ital h][sub 9/2]) configuration. The second band has been interpreted as being based on a [pi]([ital h][sub 11/2])[sup 3][direct product][nu][ital i][sub 13/2] intruder configuration within the second [beta][sub 2][congruent]0.3 prolate minimum. The known decoupled band in [sup 132]Pr (5[ital n] reaction channel) and the highly deformed band in [sup 130]La A([alpha]3[ital n]) have also been extended. The structure of all of these bands is discussed together with similar bands in nieghboring odd-odd nuclei.

  1. PR: Essentially Essential...the MISD Communication Team Training Handbook.

    ERIC Educational Resources Information Center

    Moore, Edward H.; Banach, William J., Ed.

    The suggestions, discussions, examples, and tips presented in this handbook are intended to help educators improve their public relations (PR) and communications skills. The first of the book's six chapters introduces the need for a written communications policy, good PR, regular communications, and feedback from audiences. The chapter's…

  2. PrEP (Pre-Exposure Prophylaxis) 101

    MedlinePlus

    ... negative and have taken PrEP for up to 5 years, no significant health effects have been seen. Learn more about how to protect yourself and get information tailored to meet your needs from CDC’s HIV Risk Reduction Tool (BETA). Can you start PrEP after you have ...

  3. Case Studies in e-RPL and e-PR

    ERIC Educational Resources Information Center

    Cameron, Roslyn; Miller, Allison

    2014-01-01

    The use of ePortfolios for recognition of prior learning (e-RPL) and for professional recognition (e-PR) is slowly gaining in popularity in the VET sector however their use is sporadic across educational sectors, disciplines, educational institutions and professions. Added to this is an array of purposes and types of e-RPL and e-PR models and…

  4. 33 CFR 110.255 - Ponce Harbor, P.R.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Floats for marking anchors in place will be allowed; stakes or mooring piles are prohibited. 33 CFR Ch. I... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Ponce Harbor, P.R. 110.255... ANCHORAGE REGULATIONS Anchorage Grounds § 110.255 Ponce Harbor, P.R. (a) Small-craft anchorage. On...

  5. 33 CFR 110.255 - Ponce Harbor, P.R.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Floats for marking anchors in place will be allowed; stakes or mooring piles are prohibited. 33 CFR Ch. I... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Ponce Harbor, P.R. 110.255... ANCHORAGE REGULATIONS Anchorage Grounds § 110.255 Ponce Harbor, P.R. (a) Small-craft anchorage. On...

  6. 33 CFR 110.255 - Ponce Harbor, P.R.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Floats for marking anchors in place will be allowed; stakes or mooring piles are prohibited. 33 CFR Ch. I... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Ponce Harbor, P.R. 110.255... ANCHORAGE REGULATIONS Anchorage Grounds § 110.255 Ponce Harbor, P.R. (a) Small-craft anchorage. On...

  7. 33 CFR 110.255 - Ponce Harbor, P.R.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) Floats for marking anchors in place will be allowed; stakes or mooring piles are prohibited. 33 CFR Ch. I... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Ponce Harbor, P.R. 110.255... ANCHORAGE REGULATIONS Anchorage Grounds § 110.255 Ponce Harbor, P.R. (a) Small-craft anchorage. On...

  8. 33 CFR 110.255 - Ponce Harbor, P.R.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Floats for marking anchors in place will be allowed; stakes or mooring piles are prohibited. 33 CFR Ch. I... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Ponce Harbor, P.R. 110.255... ANCHORAGE REGULATIONS Anchorage Grounds § 110.255 Ponce Harbor, P.R. (a) Small-craft anchorage. On...

  9. Praseodymium(III) sulfate hydroxide, Pr(SO(4))(OH).

    PubMed

    Wang, Xiao-Juan; Cheng, Jian-Wen

    2011-01-15

    The title compound, Pr(SO(4))(OH), obtained under hydro-thermal conditions, consists of Pr(III) ions coordinated by nine O atoms from six sulfate groups and three hydroxide anions. The bridging mode of the O atoms results in the formation of a three-dimensional framework, stabilized by two O-H⋯O hydrogen-bonding inter-actions.

  10. Achieving optimum loop shapes in quaternary Pr-Co alloys

    NASA Astrophysics Data System (ADS)

    Branagan, D. J.; Kramer, M. J.; Tang, Yali; McCallum, R. W.

    2000-05-01

    The magnetic properties and microstructures of a quaternary Pr-Co-Ti-C alloy were investigated. After heat treating at 800 °C, the quaternary alloy developed high coercivity (16.7 kOe) and high energy product (8.6 MGOe). Hysteretic loop shapes exhibiting single-phase magnetic character were achieved which was a problem which previously plagued development of Pr-Co alloys. The optimum microstructure contained 75-100 nm Pr1Co5 hard magnetic grains, 75-100 nm Pr1Co2 second phases, and <10 nm TiC grain boundary precipitates. The important factors in achieving optimum loop shapes in Pr-Co alloys were examined in detail.

  11. PK-sensitive PrPSc is infectious and shares basic structural features with PK-resistant PrPSc

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the main characteristics of the transmissible isoform of the prion protein (PrPSc) is its partial resistance to proteinase K (PK) digestion. Diagnosis of prion disease typically relies upon immunodetection of PK-digested PrPSc following Western blot or ELISA. More recently, researchers determ...

  12. PrP N-terminal domain triggers PrP{sup Sc}-like aggregation of Dpl

    SciTech Connect

    Erlich, Paul; Cesbron, Jean-Yves; Lemaire-Vieille, Catherine; Curt, Aurelie; Andrieu, Jean-Pierre; Schoehn, Guy; Jamin, Marc; Gagnon, Jean

    2008-01-18

    Transmissible spongiform encephalopathies are fatal neurodegenerative disorders thought to be transmitted by self-perpetuating conformational conversion of a neuronal membrane glycoprotein (PrP{sup C}, for 'cellular prion protein') into an abnormal state (PrP{sup Sc}, for 'scrapie prion protein'). Doppel (Dpl) is a protein that shares significant biochemical and structural homology with PrP{sup C}. In contrast to its homologue PrP{sup C}, Dpl is unable to participate in prion disease progression or to achieve an abnormal PrP{sup Sc}-like state. We have constructed a chimeric mouse protein, composed of the N-terminal domain of PrP{sup C} (residues 23-125) and the C-terminal part of Dpl (residues 58-157). This chimeric protein displays PrP-like biochemical and structural features; when incubated in presence of NaCl, the {alpha}-helical monomer forms soluble {beta}-sheet-rich oligomers which acquire partial resistance to pepsin proteolysis in vitro, as do PrP oligomers. Moreover, the presence of aggregates akin to protofibrils is observed in soluble oligomeric species by electron microscopy.

  13. Enthalpies of formation of Cd–Pr intermetallic compounds and thermodynamic assessment of the Cd–Pr system

    PubMed Central

    Reichmann, Thomas L.; Richter, Klaus W.; Delsante, Simona; Borzone, Gabriella; Ipser, Herbert

    2014-01-01

    In the present study standard enthalpies of formation were measured by reaction and solution calorimetry at stoichiometric compositions of Cd2Pr, Cd3Pr, Cd58Pr13 and Cd6Pr. The corresponding values were determined to be −46.0, −38.8, −35.2 and −24.7 kJ/mol(at), respectively. These data together with thermodynamic data and phase diagram information from literature served as input data for a CALPHAD-type optimization of the Cd–Pr phase diagram. The complete composition range could be described precisely with the present models, both with respect to phase equilibria as well as to thermodynamic input data. The thermodynamic parameters of all intermetallic compounds were modelled following Neumann–Kopp rule. Temperature dependent contributions to the individual Gibbs energies were used for all compounds. Extended solid solubilities are well described for the low- and high-temperature modifications of Pr and also for the intermetallic compound CdPr. A quite good agreement with all viable data available from literature was found and is presented. PMID:25540475

  14. Infectivity-associated PrP(Sc) and disease duration-associated PrP(Sc) of mouse BSE prions.

    PubMed

    Miyazawa, Kohtaro; Okada, Hiroyuki; Masujin, Kentaro; Iwamaru, Yoshifumi; Yokoyama, Takashi

    2015-01-01

    Disease-related prion protein (PrP(Sc)), which is a structural isoform of the host-encoded cellular prion protein, is thought to be a causative agent of transmissible spongiform encephalopathies. However, the specific role of PrP(Sc) in prion pathogenesis and its relationship to infectivity remain controversial. A time-course study of prion-affected mice was conducted, which showed that the prion infectivity was not simply proportional to the amount of PrP(Sc) in the brain. Centrifugation (20,000 ×g) of the brain homogenate showed that most of the PrP(Sc) was precipitated into the pellet, and the supernatant contained only a slight amount of PrP(Sc). Interestingly, mice inoculated with the obtained supernatant showed incubation periods that were approximately 15 d longer than those of mice inoculated with the crude homogenate even though both inocula contained almost the same infectivity. Our results suggest that a small population of fine PrP(Sc) may be responsible for prion infectivity and that large, aggregated PrP(Sc) may contribute to determining prion disease duration.

  15. Clinician attitudes toward CDC interim pre-exposure prophylaxis (PrEP) guidance and operationalizing PrEP for adolescents.

    PubMed

    Mullins, Tanya L Kowalczyk; Lally, Michelle; Zimet, Gregory; Kahn, Jessica A

    2015-04-01

    Prior to issuing formal HIV pre-exposure prophylaxis (PrEP) clinical practice guidelines in 2014, the US Centers for Disease Control and Prevention (CDC) had released interim guidance for oral PrEP use among adults. Because oral PrEP may be used off-label for youth and may soon be indicated for minor adolescents, we examined the potential adoption of the interim guidance among clinicians who care for HIV-infected and at-risk youth. Individual, semi-structured interviews were conducted with 15 US clinicians who were recruited through an adolescent HIV research network. The theory-driven interview guide, consisting primarily of open-ended questions, assessed demographics, familiarity with the guidance, attitudes toward the guidance, and attitudes toward the use of the guidance for adult and adolescent patients. Transcripts were analyzed using framework analysis. Most clinicians (11/15) reported that the guidance was compatible with their practice, although several reported that some aspects, particularly frequency of follow-up visits, needed to be tailored to meet their patients' needs. We found variability in clinician reported characteristics of appropriate PrEP candidates (e.g., youth with substance use and mental health issues were noted to be both suitable and unsuitable PrEP candidates) and PrEP use in serodiscordant couples (e.g., whether PrEP would be recommended to a patient whose HIV-infected partner is virally suppressed). Clinician reported steps for initiation, monitoring, and discontinuing PrEP were largely consistent with the guidance. The observed variability in clinician practice with regard to oral PrEP may be reduced through interventions to educate clinicians about the content and rationale for guideline recommendations.

  16. IgA- and SIgA anti-PR3 antibodies in serum versus organ involvement and disease activity in PR3-ANCA-associated vasculitis.

    PubMed

    Sandin, C; Eriksson, P; Segelmark, M; Skogh, T; Kastbom, A

    2016-05-01

    Circulating immunoglobulin (Ig)A class anti-neutrophil cytoplasm antibodies (ANCA) directed against proteinase 3 (PR3) have been reported in ANCA-associated vasculitis (AAV) with mucosal involvement. However, secretory IgA (SIgA) PR3-ANCA has not been reported previously. In this study we compared serum levels of SIgA PR3-ANCA and IgA PR3-ANCA with IgG PR3-ANCA in relation to disease characteristics. Among 73 patients with AAV and PR3-ANCA at diagnosis, 84% tested positive for IgG PR3-ANCA, 47% for IgA-ANCA and 36% for SIgA PR3-ANCA at the time of sampling for the present study. IgA and IgG PR3-ANCA were represented similarly among patients with different organ manifestations, i.e. upper airway, lung or kidney at time of sampling. However, SIgA PR3-ANCA was significantly less represented among patients with upper airway involvement. During active disease, the proportions of IgA PR3-ANCA and SIgA PR3-ANCA-positive patients were significantly higher compared to inactive disease. Eight patients were sampled prospectively during 24 months from onset of active disease. In these patients, IgA PR3-ANCA and SIgA PR3-ANCA turned negative more often after remission induction compared to IgG PR3-ANCA. Our findings suggest that serum IgA PR3-ANCA and SIgA PR3-ANCA are related more closely to disease activity in AAV compared to IgG PR3-ANCA. Further studies are required to reveal if this has implications for disease activity monitoring. The mean number of PR3-ANCA isotypes increased along with disease activity, suggesting a global B cell activation during active disease.

  17. Thermodynamic assessment of the Pr-O system

    SciTech Connect

    McMurray, Jake W.

    2015-12-24

    We found that the Calphad method was used to perform a thermodynamic assessment of the Pr–O system. Compound energy formalism representations were developed for the fluorite α-PrO 2–x and bixbyite σ-Pr 3 O 5 ± x solid solutions while the two-sublattice liquid model was used to describe the binary melt. The series of phases between Pr 2 O 3 and PrO 2 were taken to be stoichiometric. Moreover, the equilibrium oxygen pressure, phase equilibria, and enthalpy data were used to optimize the adjustable parameters of the models for a self-consistent representation of the thermodynamic behavior of the Pr–O system from 298 K to melting.

  18. Thermodynamic assessment of the Pr-O system

    DOE PAGES

    McMurray, Jake W.

    2015-12-24

    We found that the Calphad method was used to perform a thermodynamic assessment of the Pr–O system. Compound energy formalism representations were developed for the fluorite α-PrO 2–x and bixbyite σ-Pr 3 O 5 ± x solid solutions while the two-sublattice liquid model was used to describe the binary melt. The series of phases between Pr 2 O 3 and PrO 2 were taken to be stoichiometric. Moreover, the equilibrium oxygen pressure, phase equilibria, and enthalpy data were used to optimize the adjustable parameters of the models for a self-consistent representation of the thermodynamic behavior of the Pr–O system frommore » 298 K to melting.« less

  19. PrEP implementation research in Africa: what is new?

    PubMed Central

    Cowan, Frances M; Delany-Moretlwe, Sinead; Sanders, Eduard J; Mugo, Nelly R; Guedou, Fernand A; Alary, Michel; Behanzin, Luc; Mugurungi, Owen; Bekker, Linda-Gail

    2016-01-01

    Introduction Of the two million new HIV infections in adults in 2014, 70% occurred in sub-Saharan Africa. Several African countries have already approved guidelines for pre-exposure prophylaxis (PrEP) for individuals at substantial risk of HIV as part of combination HIV prevention but key questions remain about how to identify and deliver PrEP to those at greatest need. Throughout the continent, individuals in sero-discordant relationships, and members of key populations (sex workers, men who have sex with men (MSM), transgender women and injection drug users) are likely to benefit from the availability of PrEP. In addition, adolescent girls and young women (AGYW) are at substantial risk in some parts of the continent. It has been estimated that at least three million individuals in Africa are likely to be eligible for PrEP according to WHO's criteria. Tens of demonstration projects are planned or underway across the continent among a range of countries, populations and delivery settings. Discussion In each of the target populations, there are overarching issues related to (i) creating demand for PrEP, (ii) addressing supply-side issues and (iii) providing appropriate and tailored adherence support. Critical for creating demand for PrEP is the normalization of HIV prevention. Community-level interventions which engage opinion leaders as well as empowerment interventions for those at highest risk will be key. Critical to supply of PrEP is that services are accessible for all, including for stigmatized populations. Establishing accessible integrated services provides the opportunity to address other public health priorities including the unmet need for HIV testing, contraception and sexually transmitted infections treatment. National policies need to include minimum standards for training and quality assurance for PrEP implementation and to address supply chain issues. Adherence support needs to recognize that social and structural factors are likely to have an

  20. Thermodynamic database for the Co-Pr system

    PubMed Central

    Zhou, S.H.; Kramer, M.J.; Meng, F.Q.; McCallum, R.W.; Ott, R.T.

    2016-01-01

    In this article, we describe data on (1) compositions for both as-cast and heat treated specimens were summarized in Table 1; (2) the determined enthalpy of mixing of liquid phase is listed in Table 2; (3) thermodynamic database of the Co-Pr system in TDB format for the research articled entitle Chemical partitioning for the Co-Pr system: First-principles, experiments and energetic calculations to investigate the hard magnetic phase W. PMID:26900594

  1. Thermodynamic database for the Co-Pr system.

    PubMed

    Zhou, S H; Kramer, M J; Meng, F Q; McCallum, R W; Ott, R T

    2016-03-01

    In this article, we describe data on (1) compositions for both as-cast and heat treated specimens were summarized in Table 1; (2) the determined enthalpy of mixing of liquid phase is listed in Table 2; (3) thermodynamic database of the Co-Pr system in TDB format for the research articled entitle Chemical partitioning for the Co-Pr system: First-principles, experiments and energetic calculations to investigate the hard magnetic phase W. PMID:26900594

  2. Membranotropic regions of the dengue virus prM protein.

    PubMed

    Nemésio, Henrique; Villalaín, José

    2014-08-19

    The Dengue virus (DENV) prM protein consists of two moieties, the pr and M domains. Apart from preventing the premature fusion activity of the DENV E protein, prM has several other unknown biological roles, displaying both protein-protein and membrane-protein interactions. Although the prM protein is an essential component of the DENV viral cycle, little is known about its biological functions and what regions of this protein are responsible for said functions. By performing an exhaustive study of membrane rupture induced by a prM peptide library on simple and complex model membranes as well as their ability to modulate the phospholipid phase transitions of 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine and 1,2-dimyristoyl-sn-glycero-3-[phospho-rac-glycerol], we identified six membranotropic regions on the prM protein. Apart from the previously identified two transmembrane segments of the protein, one of these regions probably interacts with the fusion E protein and another one, the stem segment, would interact with the membrane modulating its structure. These data will help us understand the molecular mechanism of viral entry and morphogenesis, allow the identification of new targets for the treatment of Dengue virus infection, and make possible the future development of DENV entry inhibitors. PMID:25076193

  3. 75 FR 44847 - Proposed Collection; Comment Request for Forms 943, 943-PR, 943-A, and 943A-PR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-29

    ..., Employer's Annual Tax Return for Agricultural Employees, 943-PR, Planilla Para La Declarcion Anual De La... Employees (Form 943), Planilla Para La Declarcion Anual De La Contribucion Federal Del Patrono De...

  4. Establishment of procedures for studying mPR-interacting agents and physiological roles of mPR.

    PubMed

    Tokumoto, Toshinobu; Hossain, Md Babul; Wang, Jun

    2016-07-01

    More than 10years have passed since the discovery of membrane progestin receptors (mPRs). Although the identification of mPR genes in various organisms and mPR expression patterns have been described since then, the precise physiological roles of mPRs are still unclear, except their function as a receptor for maturation-inducing steroid in fish. The wide distribution of mPRs suggests variable actions for progestins through mPRs in the tissues. Information about the physiological roles of mPRs, such as roles in the progression of breast cancer and T-cell proliferation, has gradually accumulated recently. These results suggest that mPRs are possible targets for new pharmaceuticals. We established a cell line that was transformed with cDNAs for mPRα and a recombinant luciferase gene named GloSensor. The cells can be used for monitoring the effects of ligands on mPRα based on intracellular cyclic adenosine monophosphate (cAMP) levels. Studies using these cell lines indicated that the cAMP concentration is decreased by ligands for mPRα. The results provide support for previous results suggesting that mPRα is coupled to inhibitory G protein (Gi). We also established screening methods that make it possible to screen ligands for mPR. Recently, we succeeded in expressing and purifying recombinant mPR protein in the yeast Pichia pastoris. Relatively large amounts of mPR protein with hormonal binding activity can be purified by our method. The recombinant protein will be applicable to establishing a molecular probe to detect mPR-interacting agents. To obtain decisive evidence for the roles of mPRs, we are establishing strains of medaka fish that are deficient in mPRs. In medaka, four subtypes of mPR genes (α, β, γ, and α2) have been identified. By reverse genetic screening, we have selected three to four strains in which a point mutation has been induced in the coding sequence of the mPR subtypes. However, homozygous mutants of each mPR gene showed no phenotype. The

  5. Optimizing Content for Pre-Exposure Prophylaxis (PrEP) Counseling for Men who have Sex with Men: Perspectives of PrEP Users and High-risk PrEP Naïve Men

    PubMed Central

    Taylor, S. Wade; Mayer, Kenneth H.; Elsesser, Steven M.; Mimiaga, Matthew J.; O’Cleirigh, Conall; Safren, Steven A.

    2014-01-01

    Existing trials of antiretroviral (ARV) medication as chemoprophylaxis against HIV reveal that the degree of protection is primarily dependent on product adherence. However, there is a lack of data on targets for behavioral interventions to improve adherence to ARV as prevention. Information from individuals who have used ARV as pre-exposure prophylaxis (PrEP) can inform behavioral intervention development. Thirty-nine HIV-uninfected MSM at high risk for HIV acquisition participated in one of four semi-structured focus groups. Two of the focus groups consisted of MSM who had been prescribed and used PrEP in the context of a clinical trial; the other two consisted of high-risk MSM who had not previously used PrEP. An in-depth, within-case/across-case content analysis resulted in six descriptive themes potentially salient for a PrEP adherence behavioral intervention: (1) motivations to use PrEP, (2) barriers to PrEP use, (3) facilitators to PrEP use, (4) sexual decision-making in the context of PrEP, (5) prospective PrEP education content, and, (6) perceived effective characteristics of PrEP delivery personnel. Addressing these themes in behavioral interventions in the context of prescribing PrEP may result in the optimal “packaging” public health programs that implement PrEP for high-risk MSM. PMID:24077928

  6. Seasonal PrEP for partners of migrant miners in southern Mozambique: a highly focused PrEP intervention

    PubMed Central

    Cremin, Ide; Morales, Fernando; Jewell, Britta L; O'Reilly, Kevin R; Hallett, Timothy B

    2015-01-01

    Introduction To be used most effectively, pre-exposure prophylaxis (PrEP) should be prioritized to those at high risk of acquisition and would ideally be aligned with time periods of increased exposure. Identifying such time periods is not always straightforward, however. Gaza Province in southern Mozambique is characterized by high levels of HIV transmission and circular labour migration to mines in South Africa. A strong seasonal pattern in births is observable, reflecting an increase in conception in December. Given the potential for increased HIV transmission between miners returning in December and their partners in Gaza Province, PrEP use by the latter would be a useful means of HIV prevention, especially for couples who wish to conceive. Methods A mathematical model was used to represent population-level adult heterosexual HIV transmission in Gaza Province. Increased HIV acquisition among partners of miners in December, coinciding with the miners’ return from South Africa, is represented. In addition to a PrEP intervention, the scale-up of treatment and recent scale-up of male circumcision that have occurred in Gaza are represented. Results Providing time-limited PrEP to the partners of migrant miners, as opposed to providing PrEP all year, would improve the cost per infection averted by 7.5-fold. For the cost per infection averted to be below US$3000, at least 85% of PrEP users would need to be good adherers and PrEP would need to be cheaper than US$115 per person per year. Uncertainty regarding incidence of HIV transmission among partners of miners each year in December has a strong influence on estimates of cost per infection averted. Conclusions Providing time-limited PrEP to partners of migrant miners in Gaza Province during periods of increased exposure would be a novel strategy for providing PrEP. This strategy would allow for a better prioritized intervention, with the potential to improve the efficiency of a PrEP intervention considerably, as well

  7. Novel receptor-like kinases in cacao contain PR-1 extracellular domains.

    PubMed

    Teixeira, Paulo José Pereira Lima; Costa, Gustavo Gilson Lacerda; Fiorin, Gabriel Lorencini; Pereira, Gonçalo Amarante Guimarães; Mondego, Jorge Maurício Costa

    2013-08-01

    Members of the pathogenesis-related protein 1 (PR-1) family are well-known markers of plant defence responses, forming part of the arsenal of the secreted proteins produced on pathogen recognition. Here, we report the identification of two cacao (Theobroma cacao L.) PR-1s that are fused to transmembrane regions and serine/threonine kinase domains, in a manner characteristic of receptor-like kinases (RLKs). These proteins (TcPR-1f and TcPR-1g) were named PR-1 receptor kinases (PR-1RKs). Phylogenetic analysis of RLKs and PR-1 proteins from cacao indicated that PR-1RKs originated from a fusion between sequences encoding PR-1 and the kinase domain of a LecRLK (Lectin Receptor-Like Kinase). Retrotransposition marks surround TcPR-1f, suggesting that retrotransposition was involved in the origin of PR-1RKs. Genes with a similar domain architecture to cacao PR-1RKs were found in rice (Oryza sativa), barrel medic (Medicago truncatula) and a nonphototrophic bacterium (Herpetosiphon aurantiacus). However, their kinase domains differed from those found in LecRLKs, indicating the occurrence of convergent evolution. TcPR-1g expression was up-regulated in the biotrophic stage of witches' broom disease, suggesting a role for PR-1RKs during cacao defence responses. We hypothesize that PR-1RKs transduce a defence signal by interacting with a PR-1 ligand.

  8. Valence of praseodymium in superconducting Pr(O,F)BiS2 single crystals

    NASA Astrophysics Data System (ADS)

    Ishii, Satoshi; Hongu, Yasuaki; Miura, Akira; Nagao, Masanori

    2016-06-01

    The praseodymium (Pr) valence in superconducting PrO1- x F x BiS2 (x = 0.13,0.23) single crystals was evaluated by X-ray photoelectron spectroscopy. The Pr 3d core level is split into 3d3/2 and 3d5/2 levels. Both PrO1- x F x BiS2 and Pr2S3, which contain only Pr3+, showed 3d spectra at a lower binding energy than Pr6O11, which contains both Pr3+ and Pr4+. Neither PrO1- x F x BiS2 nor Pr2S3 showed the characteristic satellites of Pr4+ in 3d5/2 spectra. The valence fluctuation between the Pr3+ and Pr4+ states was not confirmed, suggesting that Pr3+ is dominant in PrO1- x F x BiS2 (x = 0.13,0.23) single crystals.

  9. Understanding the Press Kit and Its Use by the Media: When PR Material Becomes News

    ERIC Educational Resources Information Center

    Weisgerber, Corinne

    2006-01-01

    This activity helps students understand the relationship between public relations (PR) writing and news writing by demonstrating how PR material gets used in the production of news stories. Considering that "more than 70 percent of daily newspaper copy emanates from PR-generated releases," it is important for students to learn how PR professionals…

  10. 75 FR 51531 - Proposed Collection; Comment Request for Forms 941, 941-PR, 941-SS, 941-X, 941-X(PR), Schedule B...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-20

    ... Internal Revenue Service Proposed Collection; Comment Request for Forms 941, 941-PR, 941- SS, 941-X, 941-X... Seguro Social Y Al Seguro Medicare), 941-SS (Employer's Quarterly Federal Tax Return-American Samoa, Guam... Number: 1545-0029. Form Numbers: 941, 941-PR, 941-SS, 941-X, 941-X(PR), Schedule R (Form 941), Schedule...

  11. 78 FR 47056 - Proposed Collection; Comment Request for Forms 941, 941-PR, 941-SS, 941-X, 941-X(PR), Schedule B...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-02

    ... Internal Revenue Service Proposed Collection; Comment Request for Forms 941, 941-PR, 941- SS, 941-X, 941-X... Federal Tax Return), 941-PR, 941-SS (Employer's Quarterly Federal Tax Return-American Samoa, Guam, the... Quarterly Federal Tax Return. OMB Number: 1545-0029. Form Numbers: 941, 941-PR, 941-SS, 941-X,...

  12. Probing structural differences between PrPC and PrPSc by surface nitration and acetylation: evidence of conformational change in the C-terminus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We used two chemical modifiers, tetranitromethane (TNM) and acetic anhydride, which specifically target accessible tyrosine and lysine residues, respectively, to modify Syrian hamster recombinant PrP(90-231) (rPrP) and PrP27-30, aiming at finding locations of conformational change. Modified proteins...

  13. Sialic Acid on the Glycosylphosphatidylinositol Anchor Regulates PrP-mediated Cell Signaling and Prion Formation.

    PubMed

    Bate, Clive; Nolan, William; Williams, Alun

    2016-01-01

    The prion diseases occur following the conversion of the cellular prion protein (PrP(C)) into disease-related isoforms (PrP(Sc)). In this study, the role of the glycosylphosphatidylinositol (GPI) anchor attached to PrP(C) in prion formation was examined using a cell painting technique. PrP(Sc) formation in two prion-infected neuronal cell lines (ScGT1 and ScN2a cells) and in scrapie-infected primary cortical neurons was increased following the introduction of PrP(C). In contrast, PrP(C) containing a GPI anchor from which the sialic acid had been removed (desialylated PrP(C)) was not converted to PrP(Sc). Furthermore, the presence of desialylated PrP(C) inhibited the production of PrP(Sc) within prion-infected cortical neurons and ScGT1 and ScN2a cells. The membrane rafts surrounding desialylated PrP(C) contained greater amounts of sialylated gangliosides and cholesterol than membrane rafts surrounding PrP(C). Desialylated PrP(C) was less sensitive to cholesterol depletion than PrP(C) and was not released from cells by treatment with glimepiride. The presence of desialylated PrP(C) in neurons caused the dissociation of cytoplasmic phospholipase A2 from PrP-containing membrane rafts and reduced the activation of cytoplasmic phospholipase A2. These findings show that the sialic acid moiety of the GPI attached to PrP(C) modifies local membrane microenvironments that are important in PrP-mediated cell signaling and PrP(Sc) formation. These results suggest that pharmacological modification of GPI glycosylation might constitute a novel therapeutic approach to prion diseases.

  14. Sialic Acid on the Glycosylphosphatidylinositol Anchor Regulates PrP-mediated Cell Signaling and Prion Formation.

    PubMed

    Bate, Clive; Nolan, William; Williams, Alun

    2016-01-01

    The prion diseases occur following the conversion of the cellular prion protein (PrP(C)) into disease-related isoforms (PrP(Sc)). In this study, the role of the glycosylphosphatidylinositol (GPI) anchor attached to PrP(C) in prion formation was examined using a cell painting technique. PrP(Sc) formation in two prion-infected neuronal cell lines (ScGT1 and ScN2a cells) and in scrapie-infected primary cortical neurons was increased following the introduction of PrP(C). In contrast, PrP(C) containing a GPI anchor from which the sialic acid had been removed (desialylated PrP(C)) was not converted to PrP(Sc). Furthermore, the presence of desialylated PrP(C) inhibited the production of PrP(Sc) within prion-infected cortical neurons and ScGT1 and ScN2a cells. The membrane rafts surrounding desialylated PrP(C) contained greater amounts of sialylated gangliosides and cholesterol than membrane rafts surrounding PrP(C). Desialylated PrP(C) was less sensitive to cholesterol depletion than PrP(C) and was not released from cells by treatment with glimepiride. The presence of desialylated PrP(C) in neurons caused the dissociation of cytoplasmic phospholipase A2 from PrP-containing membrane rafts and reduced the activation of cytoplasmic phospholipase A2. These findings show that the sialic acid moiety of the GPI attached to PrP(C) modifies local membrane microenvironments that are important in PrP-mediated cell signaling and PrP(Sc) formation. These results suggest that pharmacological modification of GPI glycosylation might constitute a novel therapeutic approach to prion diseases. PMID:26553874

  15. Synthesis of praseodymium hydroxide (Pr(OH)3) and praseodymium oxide (Pr6O11) nanorods via room temperature aging.

    PubMed

    Dodd, Aaron

    2013-02-15

    In this study, room-temperature aging has been investigated as an alternative to high-temperature hydrothermal processing for manufacturing Pr(OH)(3) nanorods. It was found that a simple process consisting of precipitation, washing, and room-temperature aging results in the formation of Pr(OH)(3) nanorods that are structurally different to those synthesized by hydrothermal processing. Rather than single crystals, the nanorods were found to consist of crystals viewed down the [12¯10] and [11¯00] axes sharing a common [0001] growth direction. Subsequent calcination yielded Pr(6)O(11) nanorods consisting of cubic crystals viewed down the [11¯0] and [11¯2¯] directions. The constituent crystals shared a common [110] direction parallel with the longitudinal rod axis.

  16. Anti-Prion Drug mPPIg5 Inhibits PrPC Conversion to PrPSc

    PubMed Central

    McCarthy, James M.; Franke, Markus; Resenberger, Ulrike K.; Waldron, Sibeal; Simpson, Jeremy C.; Tatzelt, Jörg; Appelhans, Dietmar; Rogers, Mark S.

    2013-01-01

    Prion diseases, also known as transmissible spongiform encephalopathies, are a group of fatal neurodegenerative diseases that include scrapie in sheep, bovine spongiform encephalopathy (BSE) in cattle and Creutzfeldt-Jakob disease (CJD) in humans. The ‘protein only hypothesis’ advocates that PrPSc, an abnormal isoform of the cellular protein PrPC, is the main and possibly sole component of prion infectious agents. Currently, no effective therapy exists for these diseases at the symptomatic phase for either humans or animals, though a number of compounds have demonstrated the ability to eliminate PrPSc in cell culture models. Of particular interest are synthetic polymers known as dendrimers which possess the unique ability to eliminate PrPSc in both an intracellular and in vitro setting. The efficacy and mode of action of the novel anti-prion dendrimer mPPIg5 was investigated through the creation of a number of innovative bio-assays based upon the scrapie cell assay. These assays were used to demonstrate that mPPIg5 is a highly effective anti-prion drug which acts, at least in part, through the inhibition of PrPC to PrPSc conversion. Understanding how a drug works is a vital component in maximising its performance. By establishing the efficacy and method of action of mPPIg5, this study will help determine which drugs are most likely to enhance this effect and also aid the design of dendrimers with anti-prion capabilities for the future. PMID:23383136

  17. Effect of Lu-to-Y ratio and Mo coactivation on scintillation properties of LuYAG:Pr and LuAG:Pr,Mo crystals

    NASA Astrophysics Data System (ADS)

    Drozdowski, W.; Brylew, K.; Witkowski, M. E.; Drewniak, A.; Masewicz, Z.; Wojtowicz, A. J.; Kisielewski, J.; Świrkowicz, M.

    2016-09-01

    In this paper the basic scintillation and thermoluminescence properties of LuYAG:Pr and LuAG:Pr,Mo crystals are reported. It is shown that, primarily, both materials display significantly higher scintillation yields than their prototype LuAG:Pr. The results of radioluminescence, low and high temperature thermoluminescence, and scintillation time profile measurements are analyzed quantitatively to allow us a better understanding of the scintillation process in LuYAG:Pr and LuAG:Pr,Mo, as well as to let us propose or verify possible explanations of the observed yield enhancement.

  18. In vitro neutralization of prions with PrPSc-specific antibodies

    PubMed Central

    Taschuk, Ryan; Van der Merwe, Jacques; Marciniuk, Kristen; Potter, Andrew; Cashman, Neil; Griebel, Philip; Napper, Scott

    2015-01-01

    Abstract Prion diseases reflect the misfolding of a self-protein (PrPC) into an infectious, pathological isomer (PrPSc). By targeting epitopes uniquely exposed by misfolding, our group developed PrPSc-specific vaccines to 3 disease specific epitopes (DSEs). Here, antibodies induced by individual DSE vaccines are evaluated for their capacity to neutralize prions in vitro. For both purified antibodies and immunoreactive sera, the PrPSc-specific antibodies were equally effective in neutralizing prions. Further, there was no significant increase in neutralizing activity when multiple DSEs were targeted within an assay. At a low antibody concentration, the PrPSc-specific antibodies matched the neutralization achieved by an antibody that may act via both PrPC and PrPSc. At higher doses, however, this pan-specific antibody was more effective, potentially due to a combined deactivation of PrPSc and depletion of PrPC. PMID:26284508

  19. In vitro neutralization of prions with PrP(Sc)-specific antibodies.

    PubMed

    Taschuk, Ryan; Van der Merwe, Jacques; Marciniuk, Kristen; Potter, Andrew; Cashman, Neil; Griebel, Philip; Napper, Scott

    2015-01-01

    Prion diseases reflect the misfolding of a self-protein (PrP(C)) into an infectious, pathological isomer (PrP(Sc)). By targeting epitopes uniquely exposed by misfolding, our group developed PrP(Sc)-specific vaccines to 3 disease specific epitopes (DSEs). Here, antibodies induced by individual DSE vaccines are evaluated for their capacity to neutralize prions in vitro. For both purified antibodies and immunoreactive sera, the PrP(Sc)-specific antibodies were equally effective in neutralizing prions. Further, there was no significant increase in neutralizing activity when multiple DSEs were targeted within an assay. At a low antibody concentration, the PrP(Sc)-specific antibodies matched the neutralization achieved by an antibody that may act via both PrP(C) and PrP(Sc). At higher doses, however, this pan-specific antibody was more effective, potentially due to a combined deactivation of PrP(Sc) and depletion of PrP(C).

  20. Convection-Enhanced Delivery of AAV2-PrPshRNA in Prion-Infected Mice

    PubMed Central

    Ahn, Misol; Bajsarowicz, Krystyna; Oehler, Abby; Lemus, Azucena; Bankiewicz, Krystof; DeArmond, Stephen J.

    2014-01-01

    Prion disease is caused by a single pathogenic protein (PrPSc), an abnormal conformer of the normal cellular prion protein PrPC. Depletion of PrPC in prion knockout mice makes them resistant to prion disease. Thus, gene silencing of the Prnp gene is a promising effective therapeutic approach. Here, we examined adeno-associated virus vector type 2 encoding a short hairpin RNA targeting Prnp mRNA (AAV2-PrP-shRNA) to suppress PrPC expression both in vitro and in vivo. AAV2-PrP-shRNA treatment suppressed PrP levels and prevented dendritic degeneration in RML-infected brain aggregate cultures. Infusion of AAV2-PrP-shRNA-eGFP into the thalamus of CD-1 mice showed that eGFP was transported to the cerebral cortex via anterograde transport and the overall PrPC levels were reduced by ∼70% within 4 weeks. For therapeutic purposes, we treated RML-infected CD-1 mice with AAV2-PrP-shRNA beginning at 50 days post inoculation. Although AAV2-PrP-shRNA focally suppressed PrPSc formation in the thalamic infusion site by ∼75%, it did not suppress PrPSc formation efficiently in other regions of the brain. Survival of mice was not extended compared to the untreated controls. Global suppression of PrPC in the brain is required for successful therapy of prion diseases. PMID:24866748

  1. Magnetic relaxation behaviour in Pr2NiSi3

    NASA Astrophysics Data System (ADS)

    Pakhira, Santanu; Mazumdar, Chandan; Ranganathan, R.

    2016-05-01

    Time dependent isothemal remanent magnetizatin (IRM) behaviour for polycrystalline compound Pr2NiSi3 have been studied below its characteristic temperature. The compound undergoes slow magnetic relaxation with time. Along with competing interaction, non-magnetic atom disorder plays an important role in formation of non-equilibrium glassy like ground state for this compound.

  2. Commentary: Communications Doesn't Define PR, It Diminishes It.

    ERIC Educational Resources Information Center

    Budd, John, Jr.

    1995-01-01

    Gives the dictionary definition of "communications," and then suggests that communications is the last act in the process of public relations. Presents hypothetical situations to show that PR is the final implementation step in a management process rather than just "communications." Argues that some companies, however, use communication as a…

  3. Marketing Your Library Program--More than a PR Campaign.

    ERIC Educational Resources Information Center

    Brown, Gerald R.

    In this workshop, the concept of marketing was applied to school library media programs by examining the relationship between library media programs, the marketing plan, public relations (PR), and promotion. Reachable goals, targeting the audience, advertising, and motivation and commitment of the staff were also considered, and successful…

  4. Involving ALL Your Publics. Basic School PR Guide.

    ERIC Educational Resources Information Center

    Ascough, Larry

    To help educators improve their school public relations (PR) programs, this handbook tells them how to identify and communicate with "special publics" and how to evaluate their communication efforts. An introductory overview points out that two-thirds to three-quarters of the adult population have no children in school and that schools need to…

  5. Selective recognition of Pr3+ based on fluorescence enhancement sensor.

    PubMed

    Ganjali, M R; Hosseini, M; Ghafarloo, A; Khoobi, M; Faridbod, F; Shafiee, A; Norouzi, P

    2013-10-01

    (E)-2-(1-(4-hydroxy-2-oxo-2H-chromen-3-yl)ethylidene)hydrazinecarbothioamide (L) has been used to detect trace amounts of praseodymium ion in acetonitrile-water solution (MeCN/H2O) by fluorescence spectroscopy. The fluorescent probe undergoes fluorescent emission intensity enhancement upon binding to Pr(3+) ions in MeCN/H2O (9/1:v/v) solution. The fluorescence enhancement of L is attributed to a 1:1 complex formation between L and Pr(3+), which has been utilized as the basis for selective detection of Pr(3+). The sensor can be applied to the quantification of praseodymium ion with a linear range of 1.6×10(-7) to 1.0×10(-5) M. The limit of detection was 8.3×10(-8) M. The sensor exhibits high selectivity toward praseodymium ions in comparison with common metal ions. The proposed fluorescent sensor was successfully used for determination of Pr(3+) in water samples.

  6. Blue Pr{sup 3+}-doped ZBLAN fiber upconversion laser

    SciTech Connect

    Baney, D.M.; Rankin, G.; Chang, K.

    1996-09-01

    We demonstrate blue laser emission from a direct semiconductor laser-diode-pumped Pr{sup 3+}-doped upconversion fiber laser. This laser produced more than 1 mW of power at a wavelength of 492 nm from pump lasers operating at 830 and 1020 nm. {copyright} {ital 1996 Optical Society of America.}

  7. Draft Genome Sequence of Streptococcus agalactiae PR06

    PubMed Central

    MZ, Irma Syakina; Teh, L. K.

    2013-01-01

    Streptococcus agalactiae (group B streptococcus [GBS]) is a Gram-positive bacterium that was first recognized as a causative agent of bovine mastitis. S. agalactiae has subsequently emerged as a significant cause of human diseases. Here, we report the draft genome sequence of S. agalactiae PR06, which was isolated from a septicemic patient in a local hospital in Malaysia. PMID:23766409

  8. 77 FR 68102 - Foreign-Trade Zone 163-Ponce, PR; Application for Subzone; Zimmer Manufacturing BV; Ponce, PR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 163--Ponce, PR; Application for Subzone; Zimmer Manufacturing... Manufacturing BV located in Ponce, Puerto Rico. The application was submitted pursuant to the provisions of...

  9. Effects of Zn impurities on the electronic properties of Pr doped CaTiO 3

    NASA Astrophysics Data System (ADS)

    Zhu, Ailing; Wang, Jianchuan; Du, Yong; Zhao, Dongdong; Gao, Qiannan

    2012-03-01

    Microcosmic investigations of weak red-emitting materials are crucial for their further development and application. In this work, we have focused on the band structures and electronic properties of Pr mono- and (Zn, Pr) co-doped CaTiO 3 using density functional theory. Zn substitution for Ca or Ti tends to form clusters energetically with Pr substituting for Ca in CaTiO 3. In Pr mono-doped CaTiO 3, the O 2p→Ti 3d transition in CaTiO 3 host corresponds to the centered 330 nm excitation spectra. The gap states above the valence band of ∼1.30 eV and ∼2.06 eV are hybridized by Pr 4f, O 2p and Ti 3d orbitals. They are mainly due to Pr 4f orbitals in CaTiO 3:Pr. The former gap level is related to red emission at 614 nm due to 1D 2→ 3H 4 transition of Pr 3+ activator. The latter is related to the excitation spectra centered at 380 nm due to the low-lying Pr-to-mental intervalence charge transfer transitions (Pr 3+-O 2--Ti 4+⇌Pr 4+-O 2--Ti 3+). The band structures of (Zn, Pr) co-doped CaTiO 3 keep the similar gap levels to those in Pr mono-doped CaTiO 3. The incorporation of Zn brings out the two stronger localized gap states, which are hybridized by Pr 4f, O 2p and Ti 3d orbitals, in comparison with those in Pr mono-doped CaTiO 3. Therefore, when Zn impurities are added into Pr doped CaTiO 3, the present calculations visualize the two enhanced levels and the distorted structures around Pr.

  10. The N-terminal, polybasic region of PrP(C) dictates the efficiency of prion propagation by binding to PrP(Sc).

    PubMed

    Turnbaugh, Jessie A; Unterberger, Ursula; Saá, Paula; Massignan, Tania; Fluharty, Brian R; Bowman, Frederick P; Miller, Michael B; Supattapone, Surachai; Biasini, Emiliano; Harris, David A

    2012-06-27

    Prion propagation involves a templating reaction in which the infectious form of the prion protein (PrP(Sc)) binds to the cellular form (PrP(C)), generating additional molecules of PrP(Sc). While several regions of the PrP(C) molecule have been suggested to play a role in PrP(Sc) formation based on in vitro studies, the contribution of these regions in vivo is unclear. Here, we report that mice expressing PrP deleted for a short, polybasic region at the N terminus (residues 23-31) display a dramatically reduced susceptibility to prion infection and accumulate greatly reduced levels of PrP(Sc). These results, in combination with biochemical data, demonstrate that residues 23-31 represent a critical site on PrP(C) that binds to PrP(Sc) and is essential for efficient prion propagation. It may be possible to specifically target this region for treatment of prion diseases as well as other neurodegenerative disorders due to β-sheet-rich oligomers that bind to PrP(C).

  11. When and why women might suspend PrEP use according to perceived seasons of risk: implications for PrEP-specific risk-reduction counselling.

    PubMed

    Namey, Emily; Agot, Kawango; Ahmed, Khatija; Odhiambo, Jacob; Skhosana, Joseph; Guest, Greg; Corneli, Amy

    2016-09-01

    Oral pre-exposure prophylaxis (PrEP) using the antiretroviral drug emtricitabine/tenofovir disoproxil fumarate (Truvada) has been shown to dramatically reduce the risk of HIV acquisition for women at higher risk of infection if taken daily. Understanding when and why women would intentionally stop using an efficacious oral PrEP drug within the context of their 'normal' daily lives is essential for delivering effective PrEP risk-reduction counselling. As part of a larger study, we conducted 60 qualitative interviews with women at higher risk of HIV in Bondo, Kenya, and Pretoria, South Africa. Participants charted their sexual contacts over the previous six months, indicated whether they would have taken PrEP if available and discussed whether and why they would have suspended PrEP use. Nearly all participants said they would have used PrEP in the previous six months; half indicated they would have suspended PrEP use at some point. Participants' reasons for an extended break from PrEP were related to partnership dynamics (e.g., perceived low risk of a stable partner) and phases of life (e.g., trying to conceive). Life events (e.g., holidays and travel) could prompt shorter breaks in PrEP use. These circumstances may or may not correspond to actual contexts of lower risk, highlighting the importance of tailored PrEP risk-reduction counselling.

  12. PrEP in Europe – expectations, opportunities and barriers

    PubMed Central

    McCormack, Sheena Mary; Noseda, Veronica; Molina, Jean-Michel

    2016-01-01

    Introduction In contrast to the global trend showing a decline in new HIV infections, the number reported in the World Health Organization (WHO) region of Europe is increasing. Health systems are disparate, but even countries with free access to screening and treatment observe continuing high rates of new infections in key populations, notably men who have sex with men (MSM). Pre-exposure prophylaxis (PrEP) is only available in France. This commentary describes the European epidemics and healthcare settings where PrEP could be delivered, how need might be estimated for MSM and the residual barriers to access. Discussion Health systems and government commitment to HIV prevention and care, both financial and political, differ considerably between the countries that make up Europe. A common feature is that funds for prevention are a small fraction of funds for care. Although care is generally good, access is limited in the middle-income countries of Eastern Europe and central Asia, and only 19% of people living with HIV received antiretroviral therapy in 2014. It is challenging to motivate governments or civil society to implement PrEP in the context of this unmet treatment need, which is driven by limited national health budgets and diminishing assistance from foreign aid. The high-income countries of Western Europe have hesitated to embrace PrEP for different reasons, initially due to key gaps in the evidence. Now that PrEP has been shown to be highly effective in European MSM in two randomized controlled trials, it is clear that the major barrier is the cost of the drug which is still on patent, although inadequate health systems and diminishing investment in civil society are also key challenges to overcome. Conclusions The momentum to implement PrEP in European countries is increasing and provides a welcome opportunity to expand and improve clinical services and civil society support focused on HIV and related infections including other sexually transmitted and

  13. Solid-state reaction synthesis and characterization of PrB6 nanocrystals

    NASA Astrophysics Data System (ADS)

    Wei, Wei; Lihong, Bao; Yingjie, Li; Luomeng, Chao; Tegus, O.

    2015-04-01

    Crystalline PrB6 nanoparticles with the sizes ranging from 100~300 nm were synthesized by a solid-state reaction of Pr6O11/PrCl3 and NaBH4 in the temperature range of 1100~1200 °C. The crystal structure, component and morphology of the PrB6 nanoparticles were characterized by using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results show that the particles crystallize in the CsCl structure type. The selected-area electron diffraction patterns reveal the particles have single-crystalline nature. XANES study shows that the Pr atoms in the PrB6 particles are in trivalent state even if the Pr atoms possess the mixed valence state in the raw material Pr6O11.

  14. AQUIFER PROTIST RESPONSE AND THE POTENTIAL FOR TCE BIOREMEDIATION WITH BURKHOLDERIA CEPACIA G4 PR1

    EPA Science Inventory

    The introduction of bacteria into the environment for bioremediation purposes (bioaugmentation) requires analysis and monitoring of the persistence and activity of microbial population for efficacy and risk assessment purposes. Burkholderia cepacia G4 PR123 and PR131 constitutive...

  15. Constitutive expression of pathogenesis-related proteins PR-1, GRP, and PR-S in tobacco has no effect on virus infection.

    PubMed

    Linthorst, H J; Meuwissen, R L; Kauffmann, S; Bol, J F

    1989-03-01

    Samsun NN tobacco cells were transformed with chimeric genes for pathogenesis-related (PR) proteins derived from genomic (PR-1a, GRP) or cDNA (PR-S) clones under the transcriptional control of the cauliflower mosaic virus 35S promoter. Regenerated plants were assayed by RNA and protein gel blotting, and plants showing high specific expression of the inserted genes were selected for self-pollination and seed formation. Inspection of second generation transformants showed that constitutive expression of PR-1a, GRP, and PR-S in tobacco in general does not have an effect on the phenotypic appearance of the plants or the expression of other endogenous PR genes. Furthermore, constitutive expression of the above genes does not affect the susceptibility of the plants to infection with tobacco mosaic virus or alfalfa mosaic virus.

  16. Near-yrast structure of {sup 149}Pr

    SciTech Connect

    Rzaca-Urban, T.; Urban, W.; Pinston, J. A.; Simpson, G. S.; Ahmad, I.

    2010-12-15

    The neutron-rich nucleus {sup 149}Pr has been studied by means of prompt and delayed {gamma}-ray spectroscopy using the EUROGAM2 and Gammasphere arrays of Ge detectors. New spins have been assigned to a previously reported band and it is interpreted as having a h{sub 11/2} proton structure, from a comparison with quasiparticle-rotor model calculations. The strength of octupole correlations in odd-Z nuclei of the region is discussed.

  17. Public Relations: Ketchum brands new product with innovative PR strategy.

    PubMed

    2006-01-01

    Novartis Pharmaceuticals tapped publis relations (PR) giant Ketchum earlier this year to spearhead a marketing campaign that would make its new U.S. Food and Drug Administration-approved prescription-based medication, Enablex, stand out among the crowd in over active bladder (OAB) treatment. OAB is a disorder that affects an estimated 33 million Americans making this treatment highly in demand with consumers and highly competitive with other pharmaceutical companies.

  18. Progress and limits of PrP gene selection policy.

    PubMed

    Dawson, Michael; Moore, Richard C; Bishop, Stephen C

    2008-01-01

    Classical scrapie has proved to be a notoriously difficult disease to control due to a poor understanding of its natural history. The recognition of disease risk linkage to PrP genotype has offered the prospect of a disease control strategy, viz. genotyping and selective breeding, novel to veterinary medicine when first considered in the 1990s. The UK Spongiform Encephalopathy Advisory Committee recommended the exploitation of this approach in a voluntary, national programme to control classical scrapie and protect the public against food-borne exposure to bovine spongiform encephalopathy, should the national flock have been exposed via contaminated feed. The National Scrapie Plan for Great Britain was launched in 2001 and uptake has been widespread throughout the purebreeding sector of the sheep industry, with membership peaking at over 12 000 flocks in 2006. A total of 700 000 rams from 90 breeds have been genotyped. A comparison of ram lambs born in 2002 with those in 2006 shows evident changes in PrP genotype frequencies which are predicted to be associated with a reduction in disease risk. Various concerns have been raised regarding possible unintended consequences of widespread selection on PrP genotype, including impacts on other performance traits and possible effects on inbreeding and genetic diversity. To date, these concerns appear to be unfounded, as no consistent associations have been found with performance traits, nor are there likely to be any detectable impacts on inbreeding in mainstream breeds. Currently, semen banks have been implemented in Great Britain to store samples from animals of all common PrP genotypes, should these genotypes be required in the future. Various strategies to minimise future disease risks are discussed in the paper.

  19. Transition Probabilities And Chiral Symmetry In 134Pr

    SciTech Connect

    Tonev, D.; De Angelis, G.; Gadea, A.; Axiotis, M.; Marginean, N.; Martines, T.; Napoli, D.R.; Prete, G.; Behera, B.R.; Rusu, C.; Petkov, P.; Dewald, A.; Pejovic, P.; Fitzler, A.; Moeller, O.; Zell, K.O.; Balabanski, D.; Bednarczyk, P.; Camera, F.; Paleni, A.

    2005-04-05

    Lifetime measurements in 134Pr were performed by means of the Recoil distance Doppler-shift and Doppler-shift attenuation methods using the multidetector array EUROBALL, in conjunction with the inner BGO ball. The derived B(E2) transition strengths within the two bands candidates for chiral partners behave differently with increasing spin while the corresponding B(M1) values have a similar behaviour within the experimental uncertainties.

  20. Public Relations: Ketchum brands new product with innovative PR strategy.

    PubMed

    2006-01-01

    Novartis Pharmaceuticals tapped publis relations (PR) giant Ketchum earlier this year to spearhead a marketing campaign that would make its new U.S. Food and Drug Administration-approved prescription-based medication, Enablex, stand out among the crowd in over active bladder (OAB) treatment. OAB is a disorder that affects an estimated 33 million Americans making this treatment highly in demand with consumers and highly competitive with other pharmaceutical companies. PMID:17048759

  1. Getting the Most PR for Your School. NHSC Occasional Paper Number 8.

    ERIC Educational Resources Information Center

    Welch, Sally R.

    All National Home Study Council (NHSC) schools need public relations (PR) programs that are focused on the success of the school's graduates and the educational rigor and quality of its instruction rather than on the school owner's personal success or the success/size of the school. PR can be handled by schools' marketing departments. PR programs…

  2. Dimerization and protease resistance: new insight into the function of PR-1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The group 1 pathogenesis-related (PR-1) proteins have long been considered hallmarks of hypersensitive response/defense pathways in plants, but their biochemical functions are still obscure despite resolution of the NMR/X-ray structures of several PR-1-like proteins, including P14a (the prototype PR...

  3. PrP(C) signalling in neurons: from basics to clinical challenges.

    PubMed

    Hirsch, Théo Z; Hernandez-Rapp, Julia; Martin-Lannerée, Séverine; Launay, Jean-Marie; Mouillet-Richard, Sophie

    2014-09-01

    The cellular prion protein PrP(C) was identified over twenty-five years ago as the normal counterpart of the scrapie prion protein PrP(Sc), itself the main if not the sole component of the infectious agent at the root of Transmissible Spongiform Encephalopathies (TSEs). PrP(C) is a ubiquitous cell surface protein, abundantly expressed in neurons, which constitute the targets of PrP(Sc)-mediated toxicity. Converging evidence have highlighted that neuronal, GPI-anchored PrP(C) is absolutely required for prion-induced neuropathogenesis, which warrants investigating into the normal function exerted by PrP(C) in a neuronal context. It is now well-established that PrP(C) can serve as a cell signalling molecule, able to mobilize transduction cascades in response to interactions with partners. This function endows PrP(C) with the capacity to participate in multiple neuronal processes, ranging from survival to synaptic plasticity. A diverse array of data have allowed to shed light on how this function is corrupted by PrP(Sc). Recently, amyloid Aβ oligomers, whose accumulation is associated with Alzheimer's disease (AD), were shown to similarly instigate toxic events by deviating PrP(C)-mediated signalling. Here, we provide an overview of the various signal transduction cascades ascribed to PrP(C) in neurons, summarize how their subversion by PrP(Sc) or Aβ oligomers contributes to TSE or AD neuropathogenesis and discuss the ensuing clinical implications.

  4. Effects of dynamic Jahn-Teller distortions by Raman spectroscopy in the layered CMR manganite La{sub 2{minus}2x}Sr{sub 1+2x}Mn{sub 2}O{sub 7}, x = 0.36

    SciTech Connect

    Bordallo, H.N.; Argyriou, D.N.; Mitchell, J.F.; Strouse, G.F.

    1998-12-01

    The close interplay among charge, spin, and lattice degrees of freedom in the colossal magnetoresistive (CMR) manganite oxides is believed to play an important role in the transport mechanism in these itinerant ferromagnets. While the work on CMR materials has concentrated on the 3D perovskite manganites, the discovery of the layered compounds La{sub 2{minus}2x}Sr{sub 1+2x}Mn{sub 2}O{sub 7} as another class of CMR oxides provides a rich opportunity to explore the relationship between structure and transport properties on varying length and time scales in reduced dimensions. The crystal structure of the layered CMR compounds La{sub 2{minus}2x}Sr{sub 1+2x}Mn{sub 2}O{sub 7} is comprised of perovskite bilayers of corner-linked MnO{sub 6} octahedra forming infinite sheets. Doping of divalent cations such as Sr{sup 2+} gives rise to a mixed valent system were Jahn-Teller (JT) active Mn{sup 3+} and JT-inactive Mn{sup 4+} co-exist on the lattice. Among the current theoretical models of transport in the three-dimensional perovskite materials is the role of JT. This transport mechanism plays a fundamental role above the Curie temperature (T{sub c}). Indeed, localized lattice distortions have been observed experimentally above T{sub c} in the (La,Ca)MnO{sub 3} perovskite system. In this communication, the authors report resonant Raman spectroscopic measurements on a micro-crystalline sample of La{sub 1.28}Sr{sub 1.72}Mn{sub 2}O{sub 7} (x = 0.36). The measurements suggest discrete phonon modes for the Mn{sup 3+} and Mn{sup 4+} lattice sites, which may arise from either dynamic or static localization and the presence of Mn{sup 2+} defects in the lattice.

  5. Generation IV PR and PP Methods and Applications

    SciTech Connect

    Bari,R.A.

    2008-10-13

    This paper presents an evaluation methodology for proliferation resistance and physical protection (PR&PP) of Generation IV nuclear energy systems (NESs). For a proposed NES design, the methodology defines a set of challenges, analyzes system response to these challenges, and assesses outcomes. The challenges to the NES are the threats posed by potential actors (proliferant States or sub-national adversaries). The characteristics of Generation IV systems, both technical and institutional, are used to evaluate the response of the system and determine its resistance against proliferation threats and robustness against sabotage and terrorism threats. The outcomes of the system response are expressed in terms of six measures for PR and three measures for PP, which are the high-level PR&PP characteristics of the NES. The methodology is organized to allow evaluations to be performed at the earliest stages of system design and to become more detailed and more representative as design progresses. Uncertainty of results are recognized and incorporated into the evaluation at all stages. The results are intended for three types of users: system designers, program policy makers, and external stakeholders. Particular current relevant activities will be discussed in this regard. The methodology has been illustrated in a series of demonstration and case studies and these will be summarized in the paper.

  6. ER and PR signaling nodes during mammary gland development

    PubMed Central

    2012-01-01

    The ovarian hormones estrogen and progesterone orchestrate postnatal mammary gland development and are implicated in breast cancer. Most of our understanding of the molecular mechanisms of estrogen receptor (ER) and progesterone receptor (PR) signaling stems from in vitro studies with hormone receptor-positive cell lines. They have shown that ER and PR regulate gene transcription either by binding to DNA response elements directly or via other transcription factors and recruiting co-regulators. In addition they cross-talk with other signaling pathways through nongenomic mechanisms. Mouse genetics combined with tissue recombination techniques have provided insights about the action of these two hormones in vivo. It has emerged that hormones act on a subset of mammary epithelial cells and relegate biological functions to paracrine factors. With regards to hormonal signaling in breast carcinomas, global gene expression analyses have led to the identification of gene expression signatures that are characteristic of ERα-positive tumors that have stipulated functional studies of hitherto poorly understood transcription factors. Here, we highlight what has been learned about ER and PR signaling nodes in these different systems and attempt to lay out in which way the insights may converge. PMID:22809143

  7. Molecular Cloning of HbPR-1 Gene from Rubber Tree, Expression of HbPR-1 Gene in Nicotiana benthamiana and Its Inhibition of Phytophthora palmivora.

    PubMed

    Khunjan, Uraiwan; Ekchaweng, Kitiya; Panrat, Tanate; Tian, Miaoying; Churngchow, Nunta

    2016-01-01

    This is the first report to present a full-length cDNA (designated HbPR-1) encoding a putative basic HbPR-1 protein from rubber tree (Hevea brasiliensis) treated with salicylic acid. It was characterized and also expressed in Nicotiana benthamiana using Agrobacterium-mediated transient gene expression system in order to investigate the role of HbPR-1 gene in rubber tree against its oomycete pathogen Phytopthora palmivora and to produce recombinant HbPR-1 protein for microbial inhibition test. The HbPR-1 cDNA was 647 bp long and contained an open reading frame of 492 nucleotides encoding 163 amino acid residues with a predicted molecular mass of 17,681 Da and an isoelectric point (pI) of 8.56, demonstrating that HbPR-1 protein belongs to the basic PR-1 type. The predicted 3D structure of HbPR-1 was composed of four α-helices, three β-sheets, seven strands, and one junction loop. Expression and purification of recombinant HbPR-1 protein were successful using Agrobacterium-mediated transient expression and one-step of affinity chromatography. Heterologous expression of HbPR-1 in N. benthamiana reduced necrosis areas which were inoculated with P. palmivora zoospores, indicating that the expressed HbPR-1 protein played an important role in plant resistance to pathogens. The purified recombinant HbPR-1 protein was found to inhibit 64% of P. palmivora zoospore germination on a water agar plate compared with control, suggesting that it was an antimicrobial protein against P. palmivora. PMID:27337148

  8. Molecular Cloning of HbPR-1 Gene from Rubber Tree, Expression of HbPR-1 Gene in Nicotiana benthamiana and Its Inhibition of Phytophthora palmivora

    PubMed Central

    Khunjan, Uraiwan; Ekchaweng, Kitiya; Panrat, Tanate; Tian, Miaoying; Churngchow, Nunta

    2016-01-01

    This is the first report to present a full-length cDNA (designated HbPR-1) encoding a putative basic HbPR-1 protein from rubber tree (Hevea brasiliensis) treated with salicylic acid. It was characterized and also expressed in Nicotiana benthamiana using Agrobacterium-mediated transient gene expression system in order to investigate the role of HbPR-1 gene in rubber tree against its oomycete pathogen Phytopthora palmivora and to produce recombinant HbPR-1 protein for microbial inhibition test. The HbPR-1 cDNA was 647 bp long and contained an open reading frame of 492 nucleotides encoding 163 amino acid residues with a predicted molecular mass of 17,681 Da and an isoelectric point (pI) of 8.56, demonstrating that HbPR-1 protein belongs to the basic PR-1 type. The predicted 3D structure of HbPR-1 was composed of four α-helices, three β-sheets, seven strands, and one junction loop. Expression and purification of recombinant HbPR-1 protein were successful using Agrobacterium-mediated transient expression and one-step of affinity chromatography. Heterologous expression of HbPR-1 in N. benthamiana reduced necrosis areas which were inoculated with P. palmivora zoospores, indicating that the expressed HbPR-1 protein played an important role in plant resistance to pathogens. The purified recombinant HbPR-1 protein was found to inhibit 64% of P. palmivora zoospore germination on a water agar plate compared with control, suggesting that it was an antimicrobial protein against P. palmivora. PMID:27337148

  9. Cytosolic PrP Can Participate in Prion-Mediated Toxicity

    PubMed Central

    Thackray, Alana M.; Zhang, Chang; Arndt, Tina

    2014-01-01

    ABSTRACT Prion diseases are characterized by a conformational change in the normal host protein PrPC. While the majority of mature PrPC is tethered to the plasma membrane by a glycosylphosphatidylinositol anchor, topological variants of this protein can arise during its biosynthesis. Here we have generated Drosophila transgenic for cytosolic ovine PrP in order to investigate its toxic potential in flies in the absence or presence of exogenous ovine prions. While cytosolic ovine PrP expressed in Drosophila was predominantly detergent insoluble and showed resistance to low concentrations of proteinase K, it was not overtly detrimental to the flies. However, Drosophila transgenic for cytosolic PrP expression exposed to classical or atypical scrapie prion inocula showed a faster decrease in locomotor activity than similar flies exposed to scrapie-free material. The susceptibility to classical scrapie inocula could be assessed in Drosophila transgenic for panneuronal expression of cytosolic PrP, whereas susceptibility to atypical scrapie required ubiquitous PrP expression. Significantly, the toxic phenotype induced by ovine scrapie in cytosolic PrP transgenic Drosophila was transmissible to recipient PrP transgenic flies. These data show that while cytosolic PrP expression does not adversely affect Drosophila, this topological PrP variant can participate in the generation of transmissible scrapie-induced toxicity. These observations also show that PrP transgenic Drosophila are susceptible to classical and atypical scrapie prion strains and highlight the utility of this invertebrate host as a model of mammalian prion disease. IMPORTANCE During prion diseases, the host protein PrPC converts into an abnormal conformer, PrPSc, a process coupled to the generation of transmissible prions and neurotoxicity. While PrPC is principally a glycosylphosphatidylinositol-anchored membrane protein, the role of topological variants, such as cytosolic PrP, in prion-mediated toxicity and

  10. A camelid anti-PrP antibody abrogates PrP replication in prion-permissive neuroblastoma cell lines.

    PubMed

    Jones, Daryl Rhys; Taylor, William Alexander; Bate, Clive; David, Monique; Tayebi, Mourad

    2010-01-01

    The development of antibodies effective in crossing the blood brain barrier (BBB), capable of accessing the cytosol of affected cells and with higher affinity for PrP(Sc) would be of paramount importance in arresting disease progression in its late stage and treating individuals with prion diseases. Antibody-based therapy appears to be the most promising approach following the exciting report from White and colleagues, establishing the "proof-of-principle" for prion-immunotherapy. After passive transfer, anti-prion antibodies were shown to be very effective in curing peripheral but not central rodent prion disease, due to the fact that these anti-prion antibodies are relatively large molecules and cannot therefore cross the BBB. Here, we show that an anti-prion antibody derived from camel immunised with murine scrapie material adsorbed to immunomagnetic beads is able to prevent infection of susceptible N2a cells and cure chronically scrapie-infected neuroblastoma cultures. This antibody was also shown to transmigrate across the BBB and cross the plasma membrane of neurons to target cytosolic PrP(C). In contrast, treatment with a conventional anti-prion antibody derived from mouse immunised with recombinant PrP protein was unable to prevent recurrence of PrP(Sc) replication. Furthermore, our camelid antibody did not display any neurotoxic effects following treatment of susceptible N2a cells as evidenced by TUNEL staining. These findings demonstrate the potential use of anti-prion camelid antibodies for the treatment of prion and other related diseases via non-invasive means.

  11. [Aspects of progesterone receptor (PR) activity regulation - impact on breast cancer progression].

    PubMed

    Piasecka, Dominika; Składanowski, Andrzej C; Kordek, Radzisław; Romańska, Hanna M; Sądej, Rafał

    2015-01-01

    Progesterone receptor (PR) and its specific ligand play a key role in development and physiology of mammary gland. The role of PR in initiation and progression of breast carcinoma (BCa) is unquestionable, although molecular mechanism of PR action is complex and not fully understood. It is known that increased risk of breast cancer is associated with progestin-based (synthetic ligands of progesterone) hormonal contraception or hormone replacement therapies. It is estimated that ER/PR-positive tumours represent approximately 50-70% of all BCa cases, and the loss of PR is associated with resistance to hormonal therapy and increased tumour invasiveness. In classical, genomic signalling pathway cytoplasmic PR, following ligand binding, translocates to the nucleus and regulates expression of genes with the PRE sequence. PR is also involved in a large number of alternative, non-genomic signalling cascades, e.g. PR is able to activate MAPK and PI3K/AKT pathways, which leads to regulation of gene expression. The cross-talk between PR and Growth Factors Receptors (GFR) results in progesterone-independent activation of PR as well as PR-regulated GFR expression and activation. Growth factors signalling promotes formation of a pool of hypersensitive PR responsive to even very low ligand concentration. Transcriptional activity of PR as well as its dynamic impact on processes such as cell migration and adhesion are crucial for BCa progression. Further studies of multifaceted mechanisms of PR action may contribute to new PR-targeting therapeutic strategies for breast cancer patients. PMID:26689013

  12. Knowledge is Power! Increased Provider Knowledge Scores Regarding Pre-exposure Prophylaxis (PrEP) are Associated with Higher Rates of PrEP Prescription and Future Intent to Prescribe PrEP.

    PubMed

    Blumenthal, Jill; Jain, Sonia; Krakower, Douglas; Sun, Xiaoying; Young, Jason; Mayer, Kenneth; Haubrich, Richard

    2015-05-01

    The FDA approval of emtricitabine/tenofovir disoproxil fumarate for pre-exposure prophylaxis (PrEP) in 2012 has raised questions about the delivery of PrEP in a real-world setting. iPad-based questionnaires were given to providers at conferences in California and New York to assess knowledge, experience and attitudes regarding PrEP in HIV and non-HIV providers. HIV provider status was defined either by self-identification or by having greater than 5 years of HIV care experience. Knowledge scores were the sum of correct answers from five PrEP knowledge questions. Univariate analyses used t-test to compare knowledge scores and Fisher's exact test for past or future PrEP prescription between HIV and non-HIV providers. Multivariable linear or logistic regression models were used to assess factors associated with the outcomes. Of 233 respondents, the mean age was 40 years, 59 % were White, 59 % were physicians and 52 % were HIV providers. In univariate analysis, mean PrEP knowledge scores (max 5) were significantly higher for HIV providers (2.8 versus 2.2; p < 0.001), age > 41 (mean 2.8 versus 2.3; p = 0.004), White race (2.7 versus 2.2; p = 0.026) and participants in the New York region (3.0 versus 2.3; p < 0.001). In a multivariable model of knowledge scores, all but age remained significant. Among 201 potential prescribers, the rate of prior PrEP prescription was higher among HIV providers than non-HIV providers (34 versus 9 %; p < 0.001) and by knowledge score, but the association with provider status was no longer significant in multivariable analysis that controlled for knowledge. Intent to prescribe PrEP in the future was high for all provider types (64 %) and was associated with knowledge scores in multivariable analysis. The most common concerns about PrEP (>40 % of providers) were drug toxicities, development of resistance and patient adherence to follow-up; 32 % identified risk compensation as a concern. HIV providers had significantly greater PrEP knowledge

  13. HIV-negative male couples' attitudes about pre-exposure prophylaxis (PrEP) and using PrEP with a sexual agreement.

    PubMed

    Mitchell, Jason W; Lee, Ji-Young; Woodyatt, Cory; Bauermeister, José; Sullivan, Patrick; Stephenson, Rob

    2016-08-01

    One efficacious strategy to help prevent HIV is oral pre-exposure prophylaxis (PrEP), a daily regimen of antiretroviral treatment taken by HIV-negative individuals. Two of the recommendations of Centers for Disease Control and Prevention (CDC) guidelines for PrEP pertain to being in a relationship (i.e., male couples). Despite the recognition of how primary partners in male couples' relationships shape HIV risk and CDC's PrEP guidelines, there is a paucity of data that examine HIV-negative male couples' attitudes toward PrEP use and using PrEP with a sexual agreement. A sexual agreement is an explicit agreement made between two individuals about what sex and other related behaviors may occur within and outside of their relationship. In this qualitative study, we examine HIV-negative male couples' attitudes toward PrEP use and whether they thought PrEP could be integrated into a sexual agreement. Data for this study are drawn from couple-level interviews conducted in 2014 with 29 HIV-negative male couples who had a sexual agreement and were from Atlanta or Detroit. Both passive (e.g., flyers) and active (e.g., targeted Facebook advertisements) recruitment methods were used; the sample was stratified by agreement type. Thematic analysis was applied to identify the following themes regarding HIV-negative male couples' attitudes toward PrEP use: (1) PrEP and condom use; (2) concerns about PrEP (e.g., effectiveness, side effects, and promoting sexually risky behavior); and (3) accessibility of PrEP. Some thought PrEP could be a part of couples' agreement because it could help reduce sexual anxiety and sexual risk, and would help keep the couple safe. Others described PrEP use with an agreement as something for "others". Some were also concerned that incorporating PrEP could usurp the need for a sexual agreement in a couples' relationship. These themes highlight the need to improve informational messaging and promotion efforts about PrEP among HIV-negative male couples

  14. HIV-negative male couples' attitudes about pre-exposure prophylaxis (PrEP) and using PrEP with a sexual agreement.

    PubMed

    Mitchell, Jason W; Lee, Ji-Young; Woodyatt, Cory; Bauermeister, José; Sullivan, Patrick; Stephenson, Rob

    2016-08-01

    One efficacious strategy to help prevent HIV is oral pre-exposure prophylaxis (PrEP), a daily regimen of antiretroviral treatment taken by HIV-negative individuals. Two of the recommendations of Centers for Disease Control and Prevention (CDC) guidelines for PrEP pertain to being in a relationship (i.e., male couples). Despite the recognition of how primary partners in male couples' relationships shape HIV risk and CDC's PrEP guidelines, there is a paucity of data that examine HIV-negative male couples' attitudes toward PrEP use and using PrEP with a sexual agreement. A sexual agreement is an explicit agreement made between two individuals about what sex and other related behaviors may occur within and outside of their relationship. In this qualitative study, we examine HIV-negative male couples' attitudes toward PrEP use and whether they thought PrEP could be integrated into a sexual agreement. Data for this study are drawn from couple-level interviews conducted in 2014 with 29 HIV-negative male couples who had a sexual agreement and were from Atlanta or Detroit. Both passive (e.g., flyers) and active (e.g., targeted Facebook advertisements) recruitment methods were used; the sample was stratified by agreement type. Thematic analysis was applied to identify the following themes regarding HIV-negative male couples' attitudes toward PrEP use: (1) PrEP and condom use; (2) concerns about PrEP (e.g., effectiveness, side effects, and promoting sexually risky behavior); and (3) accessibility of PrEP. Some thought PrEP could be a part of couples' agreement because it could help reduce sexual anxiety and sexual risk, and would help keep the couple safe. Others described PrEP use with an agreement as something for "others". Some were also concerned that incorporating PrEP could usurp the need for a sexual agreement in a couples' relationship. These themes highlight the need to improve informational messaging and promotion efforts about PrEP among HIV-negative male couples

  15. PrP{sup C} displays an essential protective role from oxidative stress in an astrocyte cell line derived from PrP{sup C} knockout mice

    SciTech Connect

    Bertuchi, Fernanda R.; Bourgeon, Dominique M.G.; Landemberger, Michele C.; Martins, Vilma R.; Cerchiaro, Giselle

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer PrP{sup C} in solution acts as a radical scavenger. Black-Right-Pointing-Pointer PrP{sup C} reduces hydrogen peroxide toxicity in astrocytes. Black-Right-Pointing-Pointer Increase in ROS disrupted the cell cycle in the PrP{sup C}-knockout astrocytes. Black-Right-Pointing-Pointer PrP{sup C} prevents the cell death independently of an SOD-like activity. -- Abstract: The PrP{sup C} protein, which is especially present in the cellular membrane of nervous system cells, has been extensively studied for its controversial antioxidant activity. In this study, we elucidated the free radical scavenger activity of purified murine PrP{sup C} in solution and its participation as a cell protector in astrocytes that were subjected to treatment with an oxidant. In vitro and using an EPR spin-trapping technique, we observed that PrP{sup C} decreased the oxidation of the DMPO trap in a Fenton reaction system (Cu{sup 2+}/ascorbate/H{sub 2}O{sub 2}), which was demonstrated by approximately 70% less DMPO/OH{sup {center_dot}}. In cultured PrP{sup C}-knockout astrocytes from mice, the absence of PrP{sup C} caused an increase in intracellular ROS (reactive oxygen species) generation during the first 3 h of H{sub 2}O{sub 2} treatment. This rapid increase in ROS disrupted the cell cycle in the PrP{sup C}-knockout astrocytes, which increased the population of cells in the sub-G1 phase when compared with cultured wild-type astrocytes. We conclude that PrP{sup C} in solution acts as a radical scavenger, and in astrocytes, it is essential for protection from oxidative stress caused by an external chemical agent, which is a likely condition in human neurodegenerative CNS disorders and pathological conditions such as ischemia.

  16. PrP mRNA and protein expression in brain and PrP(c) in CSF in Creutzfeldt-Jakob disease MM1 and VV2.

    PubMed

    Llorens, Franc; Ansoleaga, Belén; Garcia-Esparcia, Paula; Zafar, Saima; Grau-Rivera, Oriol; López-González, Irene; Blanco, Rosi; Carmona, Margarita; Yagüe, Jordi; Nos, Carlos; Del Río, José Antonio; Gelpí, Ellen; Zerr, Inga; Ferrer, Isidre

    2013-01-01

    Creutzfeldt-Jakob disease (CJD) is a heterogenic neurodegenerative disorder associated with abnormal post-translational processing of cellular prion protein (PrP(c)). CJD displays distinctive clinical and pathological features which correlate with the genotype at the codon 129 (methionine or valine: M or V respectively) in the prion protein gene and with size of the protease-resistant core of the abnormal prion protein PrP(sc) (type 1: 20/21 kDa and type 2: 19 kDa). MM1 and VV2 are the most common sporadic CJD (sCJD) subtypes. PrP mRNA expression levels in the frontal cortex and cerebellum are reduced in sCJD in a form subtype-dependent. Total PrP protein levels and PrP(sc) levels in the frontal cortex and cerebellum accumulate differentially in sCJD MM1 and sCJD VV2 with no relation between PrP(sc) deposition and spongiform degeneration and neuron loss, but with microgliosis, and IL6 and TNF-α response. In the CSF, reduced PrP(c), the only form present in this compartment, occurs in sCJD MM1 and VV2. PrP mRNA expression is also reduced in the frontal cortex in advanced stages of Alzheimer disease, Lewy body disease, progressive supranuclear palsy, and frontotemporal lobe degeneration, but PrP(c) levels in brain varies from one disease to another. Reduced PrP(c) levels in CSF correlate with PrP mRNA expression in brain, which in turn reflects severity of degeneration in sCJD.

  17. Suppression of superconductivity with Pr substitution in Nd 1- xPr xBaCaCu 3O 7 system

    NASA Astrophysics Data System (ADS)

    Awana, V. P. S.; Cardoso, Claudio A.; de Lima, O. F.; Singh, Rajvir; Narlikar, A. V.; Yelon, W. B.; Malik, S. K.

    1999-05-01

    The structural, superconducting and magnetic properties of Nd 1- xPr xBaCaCu 3O 7 system with x=0.0, 0.10, 0.25, 0.35, 0.50, 0.75 and 1.0 have been investigated. X-ray diffraction results reveal that Pr substitutes isostructurally in NdBaCaCu 3O 7 (Nd:1113) superconductor with complete solubility. The superconducting transition temperature ( Tc), measured by ac susceptibility technique, decreases with increasing x. However, suppression of Tc with increasing Pr substitution is less in Nd:1113 superconductor compared to that reported for Nd 1- xPr xBa 2Cu 3O 7 system. Interestingly, in the fully Pr substituted compounds of the above series, i.e., in PrBaCaCu 3O 7 and PrBa 2Cu 3O 7, the Pr moments order antiferromagnetically with TN of 10 and 17 K, respectively. The present results along those reported earlier [V.P.S. Awana, J. Horvat, S.X. Dou, A. Sedky, A.V. Narlikar, J. Magn. Magn. Mater., 182 (1998) L280; V.P.S. Awana, S.X. Dou, S.K. Malik, Rajvir Singh, A.V. Narlikar, D.A. Landinez Tellez, J.M. Ferreira, J. Albino Aguiar, S. Uma, E. Gmelin, W.B. Yelon, J. Magn. Magn. Mater., 187 (1998) 192], clearly suggest that there is a correlation between the Tc suppression due to Pr and the magnetic ordering temperature of the fully substituted Pr moments in these systems. The TN may be taken to be a measure of the strength of hybridization between the Pr-4f electrons with Cu-O conduction band, and hence a lower TN may imply a less deleterious effect on superconductivity.

  18. The thermodynamic characteristics of vaporization in the NaI-PrI3 system

    NASA Astrophysics Data System (ADS)

    Motalov, V. B.; Kudin, L. S.; Markus, T.

    2009-05-01

    The vaporization of the NaI-PrI3 quasi-binary system was studied by high-temperature mass spectrometry over the whole concentration range. At 623-994 K, saturated vapor contained not only (NaI) n and (PrI3) n molecules ( n = 1, 2) and Na+(NaI) n ( n = 0-4) and I-(PrI3) n ( n = 1-2) ions but also mixed molecular and ionic associates recorded for the first time (NaPrI4, Na2PrI5, NaPrI{3/+}, Na2PrI{4/+}, Na3PrI{5/+}, Na4PrI{6/+}, NaPrI{5/-}, and NaPr2I{8/-}). The partial vapor pressures of molecules were calculated, and the equilibrium constants of the dissociation of neutral and charged associates were measured. The enthalpies of molecular and ion-molecular reactions were determined, and the enthalpies of formation of gaseous molecules and ions were obtained.

  19. Ubiquitin ligase gp78 targets unglycosylated prion protein PrP for ubiquitylation and degradation.

    PubMed

    Shao, Jia; Choe, Vitnary; Cheng, Haili; Tsai, Yien Che; Weissman, Allan M; Luo, Shiwen; Rao, Hai

    2014-01-01

    Prion protein PrP is a central player in several devastating neurodegenerative disorders, including mad cow disease and Creutzfeltd-Jacob disease. Conformational alteration of PrP into an aggregation-prone infectious form PrPSc can trigger pathogenic events. How levels of PrP are regulated is poorly understood. Human PrP is known to be degraded by the proteasome, but the specific proteolytic pathway responsible for PrP destruction remains elusive. Here, we demonstrate that the ubiquitin ligase gp78, known for its role in protein quality control, is critical for unglycosylated PrP ubiquitylation and degradation. Furthermore, C-terminal sequences of PrP protein are crucial for its ubiquitylation and degradation. Our study reveals the first ubiquitin ligase specifically involved in prion protein PrP degradation and PrP sequences crucial for its turnover. Our data may lead to a new avenue to control PrP level and pathogenesis. PMID:24714645

  20. Control of interfacial properties of Pr-oxide/Ge gate stack structure by introduction of nitrogen

    NASA Astrophysics Data System (ADS)

    Kato, Kimihiko; Kondo, Hiroki; Sakashita, Mitsuo; Nakatsuka, Osamu; Zaima, Shigeaki

    2011-06-01

    We have demonstrated the control of interfacial properties of Pr-oxide/Ge gate stack structure by the introduction of nitrogen. From C- V characteristics of Al/Pr-oxide/Ge 3N 4/Ge MOS capacitors, the interface state density decreases without the change of the accumulation capacitance after annealing. The TEM and TED measurements reveal that the crystallization of Pr-oxide is enhanced with annealing and the columnar structure of cubic-Pr 2O 3 is formed after annealing. From the depth profiles measured using XPS with Ar sputtering for the Pr-oxide/Ge 3N 4/Ge stack structure, the increase in the Ge component is not observed in a Pr-oxide film and near the interface between a Pr-oxide film and a Ge substrate. In addition, the N component segregates near the interface region, amorphous Pr-oxynitride (PrON) is formed at the interface. As a result, Pr-oxide/PrON/Ge stacked structure without the Ge-oxynitride interlayer is formed.

  1. Purification and Fibrillation of Full-Length Recombinant PrP

    PubMed Central

    Makarava, Natallia; Baskakov, Ilia V.

    2013-01-01

    Misfolding and aggregation of prion protein (PrP) is related to several neurodegenerative diseases in humans such as Creutzfeldt–Jacob disease, fatal familial insomnia, and Gerstmann–Straussler–Sheinker disease. Certain applications in prion area require recombinant PrP of high purity and quality. Here, we report an experimental procedure for expression and purification of full-length mammalian PrP. This protocol has been proved to yield PrP of extremely high purity that lacks PrP adducts, which are normally generated as a result of spontaneous oxidation or degradation. We also describe methods for the preparation of amyloid fibrils from recombinant PrP in vitro. Recombinant PrP fibrils can be used as a noninfectious synthetic surrogate of Prpsc for development of prion diagnostics including the generation of PrpSc-specific antibody. PMID:22528082

  2. PrPC Undergoes Basal to Apical Transcytosis in Polarized Epithelial MDCK Cells.

    PubMed

    Arkhipenko, Alexander; Syan, Sylvie; Victoria, Guiliana Soraya; Lebreton, Stéphanie; Zurzolo, Chiara

    2016-01-01

    The Prion Protein (PrP) is an ubiquitously expressed glycosylated membrane protein attached to the external leaflet of the plasma membrane via a glycosylphosphatidylinositol anchor (GPI). While the misfolded PrPSc scrapie isoform is the infectious agent of prion disease, the cellular isoform (PrPC) is an enigmatic protein with unclear function. Of interest, PrP localization in polarized MDCK cells is controversial and its mechanism of trafficking is not clear. Here we investigated PrP traffic in MDCK cells polarized on filters and in three-dimensional MDCK cysts, a more physiological model of polarized epithelia. We found that, unlike other GPI-anchored proteins (GPI-APs), PrP undergoes basolateral-to-apical transcytosis in fully polarized MDCK cells. Following this event full-length PrP and its cleavage fragments are segregated in different domains of the plasma membrane in polarized cells in both 2D and 3D cultures. PMID:27389581

  3. PrPC Undergoes Basal to Apical Transcytosis in Polarized Epithelial MDCK Cells

    PubMed Central

    Arkhipenko, Alexander; Syan, Sylvie; Victoria, Guiliana Soraya

    2016-01-01

    The Prion Protein (PrP) is an ubiquitously expressed glycosylated membrane protein attached to the external leaflet of the plasma membrane via a glycosylphosphatidylinositol anchor (GPI). While the misfolded PrPSc scrapie isoform is the infectious agent of prion disease, the cellular isoform (PrPC) is an enigmatic protein with unclear function. Of interest, PrP localization in polarized MDCK cells is controversial and its mechanism of trafficking is not clear. Here we investigated PrP traffic in MDCK cells polarized on filters and in three-dimensional MDCK cysts, a more physiological model of polarized epithelia. We found that, unlike other GPI-anchored proteins (GPI-APs), PrP undergoes basolateral-to-apical transcytosis in fully polarized MDCK cells. Following this event full-length PrP and its cleavage fragments are segregated in different domains of the plasma membrane in polarized cells in both 2D and 3D cultures. PMID:27389581

  4. The ZIP5 Ectodomain Co-Localizes with PrP and May Acquire a PrP-Like Fold That Assembles into a Dimer

    PubMed Central

    Pocanschi, Cosmin L.; Ehsani, Sepehr; Mehrabian, Mohadeseh; Wille, Holger; Reginold, William; Trimble, William S.; Wang, Hansen; Yee, Adelinda; Arrowsmith, Cheryl H.; Bozóky, Zoltán; Kay, Lewis E.; Forman-Kay, Julie D.; Rini, James M.; Schmitt-Ulms, Gerold

    2013-01-01

    The cellular prion protein (PrPC) was recently observed to co-purify with members of the LIV-1 subfamily of ZIP zinc transporters (LZTs), precipitating the surprising discovery that the prion gene family descended from an ancestral LZT gene. Here, we compared the subcellular distribution and biophysical characteristics of LZTs and their PrP-like ectodomains. When expressed in neuroblastoma cells, the ZIP5 member of the LZT subfamily was observed to be largely directed to the same subcellular locations as PrPC and both proteins were seen to be endocytosed through vesicles decorated with the Rab5 marker protein. When recombinantly expressed, the PrP-like domain of ZIP5 could be obtained with yields and levels of purity sufficient for structural analyses but it tended to aggregate, thereby precluding attempts to study its structure. These obstacles were overcome by moving to a mammalian cell expression system. The subsequent biophysical characterization of a homogeneous preparation of the ZIP5 PrP-like ectodomain shows that this protein acquires a dimeric, largely globular fold with an α-helical content similar to that of mammalian PrPC. The use of a mammalian cell expression system also allowed for the expression and purification of stable preparations of Takifugu rubripes PrP-1, thereby overcoming a key hindrance to high-resolution work on a fish PrPC. PMID:24039764

  5. PrP0\\0 mice show behavioral abnormalities that suggest PrPC has a role in maintaining the cytoskeleton.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background/Introduction. PrPC is highly conserved among mammals, but its natural function is unclear. Prnp ablated mice (PrP0/0) appear to develop normally and are able to reproduce. These observations seem to indicate that the gene is not essential for viability, in spite of it being highly conse...

  6. Registration of PR0806-80 and PR0806-81 white bean germplasm lines with resistance to BGYMV, BCMV, BCMNV and rust

    Technology Transfer Automated Retrieval System (TEKTRAN)

    PR0806-80 (Reg. No. GP-___, PI ______) and PR0806-81 (Reg. No. GP-___, PI ______) are multiple disease resistant dry bean (Phaseolus vulgaris L.) germplasm lines, adapted to the humid tropics, that were developed and released cooperatively by the University of Puerto Rico Agricultural Experiment Sta...

  7. Acceptability of Pre-Exposure Prophylaxis (PrEP) as an HIV prevention strategy: Barriers and facilitators to PrEP uptake among at-risk Peruvian populations

    PubMed Central

    Galea, Jerome T.; Kinsler, Janni J.; Salazar, Ximena; Lee, Sung-Jae; Giron, Maziel; Sayles, Jennifer N.; Cáceres, Carlos; Cunningham, William E.

    2010-01-01

    This study examined Pre-Exposure Prophylaxis (PrEP) acceptability among female sex workers, male-to-female transgendered persons, and men who have sex with men in Lima, Peru. Focus groups explored social issues associated with PrEP acceptability and conjoint analysis assessed preferences among eight hypothetical PrEP scenarios with varying attribute profiles and their relative impact on acceptability. Conjoint analysis revealed that PrEP acceptability ranged from 19.8 to 82.5 out of a possible score of 100 across the eight hypothetical PrEP scenarios. Out-of-pocket cost had the greatest impact on PrEP acceptability (25.2, p <0.001), followed by efficacy (21.4, p <0.001) and potential side effects (14.7, p <0.001). Focus group data supported these findings, and also revealed that potential sexual risk disinhibition, stigma and discrimination associated with PrEP use, and mistrust of health care professionals were also concerns. These issues will require careful attention when planning for PrEP roll-out if proven efficacious in ongoing clinical trials. PMID:21571973

  8. PR-EDB: Power Reactor Embrittlement Database - Version 3

    SciTech Connect

    Wang, Jy-An John; Subramani, Ranjit

    2008-03-01

    The aging and degradation of light-water reactor pressure vessels is of particular concern because of their relevance to plant integrity and the magnitude of the expected irradiation embrittlement. The radiation embrittlement of reactor pressure vessel materials depends on many factors, such as neutron fluence, flux, and energy spectrum, irradiation temperature, and preirradiation material history and chemical compositions. These factors must be considered to reliably predict pressure vessel embrittlement and to ensure the safe operation of the reactor. Large amounts of data from surveillance capsules are needed to develop a generally applicable damage prediction model that can be used for industry standards and regulatory guides. Furthermore, the investigations of regulatory issues such as vessel integrity over plant life, vessel failure, and sufficiency of current codes, Standard Review Plans (SRPs), and Guides for license renewal can be greatly expedited by the use of a well-designed computerized database. The Power Reactor Embrittlement Database (PR-EDB) is such a comprehensive collection of data for U.S. designed commercial nuclear reactors. The current version of the PR-EDB lists the test results of 104 heat-affected-zone (HAZ) materials, 115 weld materials, and 141 base materials, including 103 plates, 35 forgings, and 3 correlation monitor materials that were irradiated in 321 capsules from 106 commercial power reactors. The data files are given in dBASE format and can be accessed with any personal computer using the Windows operating system. "User-friendly" utility programs have been written to investigate radiation embrittlement using this database. Utility programs allow the user to retrieve, select and manipulate specific data, display data to the screen or printer, and fit and plot Charpy impact data. The PR-EDB Version 3.0 upgrades Version 2.0. The package was developed based on the Microsoft .NET framework technology and uses Microsoft Access for

  9. Protease-resistant PrP and PrP oligomers in the brain in human prion diseases after intraventricular pentosan polysulfate infusion.

    PubMed

    Honda, Hiroyuki; Sasaki, Kensuke; Minaki, Haruhiko; Masui, Kenta; Suzuki, Satoshi O; Doh-Ura, Katsumi; Iwaki, Toru

    2012-04-01

    Intraventricular infusion of pentosan polysulfate (PPS) as a treatment for various human prion diseases has been applied in Japan. To evaluate the influence of PPS treatment we performed pathological examination and biochemical analyses of PrP molecules in autopsied brains treated with PPS (one case of sporadic Creutzfeldt-Jakob disease (sCJD, case 1), two cases of dura mater graft-associated CJD (dCJD, cases 2 and 4), and one case of Gerstmann-Sträussler-Scheinker disease (GSS, case 3). Six cases of sCJD without PPS treatment were examined for comparison. Protease-resistant PrP (PrP(res) ) in the frontal lobe was evaluated by Western blotting after proteinase K digestion. Further, the degree of polymerization of PrP molecules was examined by the size-exclusion gel chromatography assay. PPS infusions were started 3-10 months after disease onset, but the treatment did not achieve any clinical improvements. Postmortem examinations of the treated cases revealed symmetrical brain lesions, including neuronal loss, spongiform change and gliosis. Noteworthy was GFAP in the cortical astrocytes reduced in all treated cases despite astrogliosis. Immunohistochemistry for PrP revealed abnormal synaptic deposits in all treated cases and further plaque-type PrP deposition in case 3 of GSS and case 4 of dCJD. Western blotting showed relatively low ratios of PrP(res) in case 2 of dCJD and case 3 of GSS, while in the treated sCJD (case 1), the ratio of PrP(res) was comparable with untreated cases. The indices of oligomeric PrP were reduced in one sCJD (case 1) and one dCJD (case 2). Although intraventricular PPS infusion might modify the accumulation of PrP oligomers in the brains of patients with prion diseases, the therapeutic effects are still uncertain.

  10. Substitution of Y for Pr in PrMn2Ge2—The magnetism of Pr0.8Y0.2Mn2Ge2

    NASA Astrophysics Data System (ADS)

    Wang, J. L.; Campbell, S. J.; Hofmann, M.; Kennedy, S. J.; Avdeev, M.; Md Din, M. F.; Zeng, R.; Cheng, Z. X.; Dou, S. X.

    2013-05-01

    Pr0.8Y0.2Mn2Ge2 is found to exhibit four magnetic transitions on decreasing the temperature from the paramagnetic region: (i) paramagnetism to intralayer antiferromagnetism (AFl) at TNintra; (ii) AFl to canted ferromagnetism (Fmc) at TCinter; (iii) Fmc to conical magnetic ordering of the Mn sublattice (Fmi) at Tcc; and (iv) Fmi(Mn) to Fmi(Mn) + F(Pr) at TCPr. These changes in magnetic structure are discussed in terms of changes in the Mn-Mn separation distances caused by the unit cell contraction and by electronic effects due to replacement of 20% of Pr with Y.

  11. Using protein misfolding cyclic amplification generates a highly neurotoxic PrP dimer causing neurodegeneration.

    PubMed

    Yang, XiuJin; Yang, LiFeng; Zhou, XiangMei; Khan, Sher Hayat; Wang, HuiNuan; Yin, XiaoMin; Yuan, Zhen; Song, ZhiQi; Wu, WenYu; Zhao, DeMing

    2013-11-01

    Under the "protein-only" hypothesis, prion-based diseases are proposed to result from an infectious agent that is an abnormal isoform of the prion protein in the scrapie form, PrP(Sc). However, since PrP(Sc) is highly insoluble and easily aggregates in vivo, this view appears to be overly simplistic, implying that the presence of PrP(Sc) may indirectly cause neurodegeneration through its intermediate soluble form. We generated a neurotoxic PrP dimer with partial pathogenic characteristics of PrP(Sc) by protein misfolding cyclic amplification in the presence of 1-palmitoyl-2-oleoylphosphatidylglycerol consisting of recombinant hamster PrP (23-231). After intracerebral injection of the PrP dimer, wild-type hamsters developed signs of neurodegeneration. Clinical symptoms, necropsy findings, and histopathological changes were very similar to those of transmissible spongiform encephalopathies. Additional investigation showed that the toxicity is primarily related to cellular apoptosis. All results suggested that we generated a new neurotoxic form of PrP, PrP dimer, which can cause neurodegeneration. Thus, our study introduces a useful model for investigating PrP-linked neurodegenerative mechanisms.

  12. Paracrine inhibition of prion propagation by anti-PrP single-chain Fv miniantibodies.

    PubMed

    Donofrio, Gaetano; Heppner, Frank L; Polymenidou, Magdalini; Musahl, Christine; Aguzzi, Adriano

    2005-07-01

    Prion diseases are characterized by the deposition of PrP(Sc), an abnormal form of the cellular prion protein PrP(C). A growing body of evidence suggests that antibodies to PrP(C) can antagonize deposition of PrP(Sc). However, host tolerance hampers the induction of immune responses to PrP(C), and cross-linking of PrP(C) by bivalent anti-PrP antibodies is neurotoxic. In order to obviate these problems, we explored the antiprion potential of recombinant single-chain antibody (scFv) fragments. scFv fragments derived from monoclonal anti-PrP antibody 6H4, flagged with c-myc and His6 tags, were correctly processed and secreted by mammalian RD-4 rhabdomyosarcoma cells. When cocultured with cells secreting anti-PrP scFv, chronically prion-infected neuroblastoma cells ceased to produce PrP(Sc), even if antibody-producing cells were physically separated from target cells in transwell cultures. Expression of scFv with irrelevant specificity, or of similarly tagged molecules, was not curative. Therefore, eukaryotically expressed scFv exerts a paracrine antiprion activity. The effector functions encoded by immunoglobulin constant domains are unnecessary for this effect. Because of their small size and their monovalent binding, scFv fragments may represent candidates for gene transfer-based immunotherapy of prion diseases.

  13. PrP106-126 peptide disrupts lipid membranes: Influence of C-terminal amidation

    SciTech Connect

    Zheng Wenfu; Wang Lijun; Hong Yuankai; Sha Yinlin

    2009-02-06

    PrP106-126 is located within the important domain concerning membrane related conformational conversion of human Prion protein (from cellular isoform PrP{sup C} to scrapie isoform PrP{sup Sc}). Recent advances reveal that the pathological and physicochemical properties of PrP106-126 peptide are very sensitive to its N-terminal amidation, however, the detailed mechanism remains unclear. In this work, we studied the interactions of the PrP106-126 isoforms (PrP106-126{sub CONH2} and PrP106-126{sub COOH}) with the neutral lipid bilayers by atomic force microscopy, surface plasmon resonance and fluorescence spectroscopy. The membrane structures were disturbed by the two isoforms in a similarly stepwise process. The distinct morphological changes of the membrane were characterized by formation of semi-penetrated defects and sigmoidal growth of flat high-rise domains on the supported lipid bilayers. However, PrP106-126{sub COOH} displayed a higher peptide-lipid binding affinity than PrP106-126{sub CONH2} ({approx}2.9 times) and facilitated the peptide-lipid interactions by shortening the lag time. These results indicate that the C-terminal amidation may influence the pathological actions of PrP106-126 by lowering the interaction potentials with lipid membranes.

  14. Analysis of cleavage site mutations between the NC and PR Gag domains of Rous sarcoma virus.

    PubMed Central

    Schatz, G; Pichova, I; Vogt, V M

    1997-01-01

    In retroviruses, the viral protease (PR) is released as a mature protein by cleavage of Gag, Gag-Pro, or Gag-Pro-Pol precursor polypeptides. In avian sarcoma and leukemia viruses (ASLV), PR forms the C-terminal domain of Gag. Based on the properties of a mutation (cs22) in the cleavage site between the upstream NC domain and the PR domain, the proteolytic liberation of PR previously was inferred to be essential for processing of Gag and Pol proteins. To study this process in more detail, we have analyzed the effects that several mutations at the NC-PR cleavage site have on proteolytic processing in virus-like particles expressed in COS and quail cells. Mutant Gag proteins carrying the same mutations also were synthesized in vitro and tested for processing with purified PR. In both types of studies, N-terminal sequencing of the liberated PR domain was carried out to exactly identify the site of cleavage. Finally, synthetic peptides corresponding to the mutant proteins were assessed for the ability to act as substrates for PR. The results were all consistent and led to the following conclusions. (i) In vivo, if normal processing between NC and PR is prevented by mutations, limited cleavage occurs at a previously unrecognized alternative site three amino acids downstream, i.e., in PR. This N-terminally truncated PR is inactive as an enzyme, as inferred from the global processing defect in cs22 and a similar mutant. (ii) In Gag proteins translated in vitro, purified PR cleaves this alternative site as rapidly as it does the wild-type site. (iii) Contrary to previously accepted rules describing retroviral cleavage sites, an isoleucine residue placed at the P1 position of the NC-PR cleavage site does not hinder normal processing. (iv) A proline residue placed at the P2 position in this cleavage site blocks normal processing. PMID:8985369

  15. An orange emitting phosphor Lu{sub 2−x}CaMg{sub 2}Si{sub 2.9}Ti{sub 0.1}O{sub 12}:xCe with pure garnet phase for warm white LEDs

    SciTech Connect

    Chu, Yaoqing; Zhang, Qinghong; Xu, Jiayue; Li, Yaogang; Wang, Hongzhi

    2015-09-15

    A new silicate garnet phosphor, Lu{sub 2−x}CaMg{sub 2}Si{sub 2.9}Ti{sub 0.1}O{sub 12}:xCe was synthesized by a high temperature solid-state reaction under reductive atmosphere. X-ray diffraction (XRD) showed that the powder was pure garnet phase. The emission and excitation spectrum indicated that the Lu{sub 2−x}CaMg{sub 2}Si{sub 2.9}Ti{sub 0.1}O{sub 12}:xCe phosphors could absorb blue light in the spectral range of 400–550 nm efficiently and exhibit bright yellow–orange emission in the range of 520–750 nm. With the increase of Ce{sup 3+} concentration, the emission band of Ce{sup 3+} showed a red shift. Interestingly, the concentration quenching occurred when the Ce{sup 3+} concentration exceeded 4 mol%. The temperature-dependent luminescent properties of the phosphors were discussed and the Lu{sub 1.96}CaMg{sub 2}Si{sub 2.9}Ti{sub 0.1}O{sub 12}:0.04Ce phosphors showed good performances in color temperature (2430 K) and potential applications for warm white LEDs. - Graphical Abstract: This image shows that the phosphor of Lu{sub 1.96}CaMg{sub 2}Si{sub 2.9}Ti{sub 0.1}O{sub 12}:0.04Ce can generate a uniform yellow tint under natural light illumination and emit orange–red light when excited by blue light. With a fixed 467 nm emission light, warm white light can be produced by this phosphor, which indicates that the phosphor is potentially applicable in warm white light emitting diodes based on GaN chips. - Highlights: • A new silicate garnet phosphor was synthesized by solid-state method. • Secondary phases can be avoided when a small amount of Si{sup 4+} were replaced by Ti{sup 4+}. • A broad emission band of Ce{sup 3+} in the phosphors was described. • The phosphors are potentially applicable in warm white light emitting diodes.

  16. PrP charge structure encodes interdomain interactions

    PubMed Central

    Martínez, Javier; Sánchez, Rosa; Castellanos, Milagros; Makarava, Natallia; Aguzzi, Adriano; Baskakov, Ilia V.; Gasset, María

    2015-01-01

    Almost all proteins contain charged residues, and their chain distribution is tailored to fulfill essential ionic interactions for folding, binding and catalysis. Among proteins, the hinged two-domain chain of the cellular prion protein (PrPC) exhibits a peculiar charge structure with unclear consequences in its structural malleability. To decipher the charge design role, we generated charge-reverted mutants for each domain and analyzed their effect on conformational and metabolic features. We found that charges contain the information for interdomain interactions. Use of dynamic light scattering and thermal denaturation experiments delineates the compaction of the α-fold by an electrostatic compensation between the polybasic 23–30 region and the α3 electronegative surface. This interaction increases stability and disfavors fibrillation. Independently of this structural effect, the N-terminal electropositive clusters regulate the α-cleavage efficiency. In the fibrillar state, use of circular dichroism, atomic-force and fluorescence microscopies reveal that the N-terminal positive clusters and the α3 electronegative surface dictate the secondary structure, the assembly hierarchy and the growth length of the fibril state. These findings show that the PrP charge structure functions as a code set up to ensure function and reduce pathogenic routes. PMID:26323476

  17. PR-Box Correlations Have No Classical Limit

    NASA Astrophysics Data System (ADS)

    Rohrlich, Daniel

    One of Yakir Aharonov's endlessly captivating physics ideas is the conjecture that two axioms, namely relativistic causality ("no superluminal signalling") and nonlocality, so nearly contradict each other that a unique theory—quantum mechanics—reconciles them. But superquantum (or "PR-box") correlations imply that quantum mechanics is not the most nonlocal theory (in the sense of nonlocal correlations) consistent with relativistic causality. Let us consider supplementing these two axioms with a minimal third axiom: there exists a classical limit in which macroscopic observables commute. That is, just as quantum mechanics has a classical limit, so must any generalization of quantum mechanics. In this classical limit, PR-box correlations violate relativistic causality. Generalized to all stronger-than-quantum bipartite correlations, this result is a derivation of Tsirelson's bound without assuming quantum mechanics. [Editors note: for a video of the talk given by Dr. Rohrlich at the Aharonov-80 conference in 2012 at Chapman University, see http://quantum.chapman.edu/talk-10.

  18. PrP charge structure encodes interdomain interactions.

    PubMed

    Martínez, Javier; Sánchez, Rosa; Castellanos, Milagros; Makarava, Natallia; Aguzzi, Adriano; Baskakov, Ilia V; Gasset, María

    2015-01-01

    Almost all proteins contain charged residues, and their chain distribution is tailored to fulfill essential ionic interactions for folding, binding and catalysis. Among proteins, the hinged two-domain chain of the cellular prion protein (PrP(C)) exhibits a peculiar charge structure with unclear consequences in its structural malleability. To decipher the charge design role, we generated charge-reverted mutants for each domain and analyzed their effect on conformational and metabolic features. We found that charges contain the information for interdomain interactions. Use of dynamic light scattering and thermal denaturation experiments delineates the compaction of the α-fold by an electrostatic compensation between the polybasic 23-30 region and the α3 electronegative surface. This interaction increases stability and disfavors fibrillation. Independently of this structural effect, the N-terminal electropositive clusters regulate the α-cleavage efficiency. In the fibrillar state, use of circular dichroism, atomic-force and fluorescence microscopies reveal that the N-terminal positive clusters and the α3 electronegative surface dictate the secondary structure, the assembly hierarchy and the growth length of the fibril state. These findings show that the PrP charge structure functions as a code set up to ensure function and reduce pathogenic routes. PMID:26323476

  19. Na+/K+-ATPase Is Present in Scrapie-Associated Fibrils, Modulates PrP Misfolding In Vitro and Links PrP Function and Dysfunction

    PubMed Central

    Graham, James F.; Kurian, Dominic; Agarwal, Sonya; Toovey, Lorna; Hunt, Lawrence; Kirby, Louise; Pinheiro, Teresa J. T.; Banner, Steven J.; Gill, Andrew C.

    2011-01-01

    Transmissible spongiform encephalopathies are characterised by widespread deposition of fibrillar and/or plaque-like forms of the prion protein. These aggregated forms are produced by misfolding of the normal prion protein, PrPC, to the disease-associated form, PrPSc, through mechanisms that remain elusive but which require either direct or indirect interaction between PrPC and PrPSc isoforms. A wealth of evidence implicates other non-PrP molecules as active participants in the misfolding process, to catalyse and direct the conformational conversion of PrPC or to provide a scaffold ensuring correct alignment of PrPC and PrPSc during conversion. Such molecules may be specific to different scrapie strains to facilitate differential prion protein misfolding. Since molecular cofactors may become integrated into the growing protein fibril during prion conversion, we have investigated the proteins contained in prion disease-specific deposits by shotgun proteomics of scrapie-associated fibrils (SAF) from mice infected with 3 different strains of mouse-passaged scrapie. Concomitant use of negative control preparations allowed us to identify and discount proteins that are enriched non-specifically by the SAF isolation protocol. We found several proteins that co-purified specifically with SAF from infected brains but none of these were reproducibly and demonstrably specific for particular scrapie strains. The α-chain of Na+/K+-ATPase was common to SAF from all 3 strains and we tested the ability of this protein to modulate in vitro misfolding of recombinant PrP. Na+/K+-ATPase enhanced the efficiency of disease-specific conversion of recombinant PrP suggesting that it may act as a molecular cofactor. Consistent with previous results, the same protein inhibited fibrillisation kinetics of recombinant PrP. Since functional interactions between PrPC and Na+/K+-ATPase have previously been reported in astrocytes, our data highlight this molecule as a key link between PrP function

  20. PrEP implementation in the Asia-Pacific region: opportunities, implementation and barriers

    PubMed Central

    Zablotska, Iryna; Grulich, Andrew E; Phanuphak, Nittaya; Anand, Tarandeep; Janyam, Surang; Poonkasetwattana, Midnight; Baggaley, Rachel; van Griensven, Frits; Lo, Ying-Ru

    2016-01-01

    Introduction HIV epidemics in the Asia-Pacific region are concentrated among men who have sex with men (MSM) and other key populations. Pre-exposure prophylaxis (PrEP) is an effective HIV prevention intervention and could be a potential game changer in the region. We discuss the progress towards PrEP implementation in the Asia-Pacific region, including opportunities and barriers. Discussion Awareness about PrEP in the Asia-Pacific is still low and so are its levels of use. A high proportion of MSM who are aware of PrEP are willing to use it. Key PrEP implementation barriers include poor knowledge about PrEP, limited access to PrEP, weak or non-existent HIV prevention programmes for MSM and other key populations, high cost of PrEP, stigma and discrimination against key populations and restrictive laws in some countries. Only several clinical trials, demonstration projects and a few larger-scale implementation studies have been implemented so far in Thailand and Australia. However, novel approaches to PrEP implementation have emerged: researcher-, facility- and community-led models of care, with PrEP services for fee and for free. The WHO consolidated guidelines on HIV testing, treatment and prevention call for an expanded access to PrEP worldwide and have provided guidance on PrEP implementation in the region. Some countries like Australia have released national PrEP guidelines. There are growing community leadership and consultation processes to initiate PrEP implementation in Asia and the Pacific. Conclusions Countries of the Asia-Pacific region will benefit from adding PrEP to their HIV prevention packages, but for many this is a critical step that requires resourcing. Having an impact on the HIV epidemic requires investment. The next years should see the region transitioning from limited PrEP implementation projects to growing access to PrEP and expansion of HIV prevention programmes. PMID:27760688

  1. Green and red luminescence in co-precipitation synthesized Pr:LuAG nanophosphor

    NASA Astrophysics Data System (ADS)

    Kumar, S. Arun; Kumar, K. Ashok; Gunaseelan, M.; Asokan, K.; Senthilselvan, J.

    2016-05-01

    Pr:LuAG nanophosphor is an effective candidate in magnetic resonance imaging coupled positron emission tomography (MRI-PET) for medical imaging and scintillator applications. LuAG:Pr (0.05, 0.15 mol%) nanoscale ceramic powders were synthesized by co-precipitation method using urea as precipitant. Effect of antisite defect on structure and luminescence behavior was investigated. Pr:LuAG nanoceramic powders are found crystallized in cubic structure by high temperature calcination at 1400 °C and it shows antisite defect. HR-SEM analysis revealed spherically shaped Pr:LuAG nanoceramic particulate powders with ˜100 nm size. By the excitation at 450 nm, Pr:LuAG nanophosphor exhibit green to red luminescence in the wavelength range of 520 to 680 nm, which is originated from multiplet transition of Pr3+ ions.

  2. Dzyaloshinsky-Moriya interaction in the enhanced nuclear magnet PrCu6

    NASA Astrophysics Data System (ADS)

    Ishii, Hiroumi; Kinoshita, Yasushi

    2001-01-01

    Recently it has been shown experimentally that the enhanced nuclear magnet PrCu6 behaves antiferromagnetically along the b axis and ferrromagnetically along the c axis. The mechanism for this anomalous magnetism is proposed here. The key lies in the crystal structure of PrCu6 with space group P21/c. In the unit cell there are two kinds of sites for Pr atoms. The neighboring atoms of one Pr are located at mirror reflection of those for another Pr. It is shown that between nuclear spins of these two Pr atoms the Dzyaloshinsky-Moriya type interaction is induced in the Ruderman-Kittel-Kasuya-Yosida interaction through the Van Vleck susceptibility. The susceptibility is calculated in the mean-field approximation, which reproduces the features of experimental results qualitatively.

  3. The matlockite-type praseodymium(III) oxide bromide PrOBr.

    PubMed

    Talmon-Gros, Pia; Schurz, Christian M; Schleid, Thomas

    2011-12-01

    The crystal structure of the praseodymium(III) oxide bromide, PrOBr, can be best described with layers of agglomerated square anti-prisms [PrO(4)Br(4)](9-). These slabs are stacked along the c axis and linked via two different secondary contacts between Pr(3+) and Br(-). The Pr(3+) cations occupy the Wyckoff site 2c with 4mm symmetry and carry four O(2-) anions as well as four primary Br(-) anions, yielding a coordination number of 8. While the Br(-) anions exhibit the same site symmetry as the Pr(3+) cations, the oxide anions are located at the Wyckoff position 2a with site symmetry [Formula: see text]m2 and have four Pr(3+) cations as neighbours, defining a tetra-hedron.

  4. Structural and magnetic properties of Pr-alloyed MnBi nanostructures

    SciTech Connect

    Kharel, P; Shah, VR; Li, XZ; Zhang, WY; Skomski, R; Shield, JE; Sellmyer, DJ

    2013-02-05

    The structural and magnetic properties of Pr-alloyed MnBi (short MnBi-Pr) nanostructures with a range of Pr concentrations are investigated. The nanostructures include thin films having Pr concentrations 0, 2, 3, 5 and 9 at.% and melt-spun ribbons having Pr concentrations 0%, 2%, 4% and 6%, respectively. Addition of Pr into the MnBi lattice has produced a significant change in the magnetic properties of these nanostructures including an increase in coercivity and structural phase transition temperature, and a decrease in saturation magnetization and anisotropy energy. The highest value of coercivity measured in the films is 23 kOe and in the ribbons is 5.6 kOe. The observed magnetic properties are explained as the consequences of competing ferromagnetic and antiferromagnetic interactions.

  5. Virulence testing and extracellular subtilisin-like (Pr1) and trypsin-like (Pr2) activity during propagule production of Paecilomyces fumosoroseus isolates from whiteflies (Homoptera: Aleyrodidae).

    PubMed

    Castellanos-Moguel, Judith; González-Barajas, Margarita; Mier, Teresa; Reyes-Montes, María Del Rocío; Aranda, Eduardo; Toriello, Conchita

    2007-03-01

    To properly characterize several isolates of Paecilomyces fumosoroseus, a fungal entomopathogen of whiteflies (Homoptera: Aleyrodidae) and other insect pests for biocontrol purposes, virulence towards Trialeurodes vaporariorum, and subtilisin-like (Pr1) and trypsin-like (Pr2) protease activity during propagule production were investigated in monospore cultures (MCs). The virulence of three MCs towards second instar whiteflies was measured and expressed as lethal median concentration (LC50). Number and widthlength ratio of propagules (blastospores, hyphal bodies, short hyphae, submerged conidia) and extracellular proteolytic activity was determined simultaneously in liquid medium. Total protease activity was assayed with azocasein, Pr1 and Pr2 activity was determined with the substrates N-Succinyl-Ala-Ala-Pro-Phe-p-nitroanilide and N-Benzoyl-Phe-Val-Arg-pnitroanilide, respectively. Natural variability in virulence, propagule production and cuticle-degrading proteases among isolates was observed. Bioassays showed a LC50 of 1.1 x 1,000, 2.5 x 10,000 and 7.6 x 10,000 conidia/ml for MCs EH-506/3, EH-503/3 and EH-520/3, respectively, EH-506/3 being the most virulent isolate. Isolate EH-503/3 produced the highest yield of propagules (7.7 x 10000000 propagules/ml), followed by EH-520/3 with 6.4 x 10000000 and EH-506/3 with 1.0 x 10000000 propagules/ml. Subtilisin-like (Pr1) and trypsin-like (Pr2) activity was present in the three MCs. Subtilisin-like (Pr1) activity was highest (745.7 UPr1/ml at 120 h) in the most virulent isolate, EH-506/3, pointing at Pr1 as a phenotypic marker of virulence for P. fumosoroseus. EH-506/3 appears to be a good candidate for whitefly biocontrol due to its high virulence, Pr1 concentration and rapid transition to blastospores in submerged liquid medium.

  6. Neutron diffraction and thermoelectric properties of indium filled In x Co 4 Sb 12 ( x=0.05, 0.2) and indium cerium filled Ce 0.05 In 0.1 Co 4 Sb 12 skutterudites: Neutron diffraction and thermoelectric properties of In/Ce skutterudites

    DOE PAGES

    Sesselmann, Andreas; Klobes, Benedikt; Dasgupta, Titas; Gourdon, Olivier; Hermann, Raphael; Mueller, Eckhard

    2015-09-25

    The thermoelectric properties on polycrystalline single (In) and double filled (Ce, In) skutterudites are characterized between 300 and 700 K. Powder neutron diffraction measurements of the skutterudite compositions InxCo4Sb12 (x= 0.05, 0.2) and Ce0.05In0.1Co4Sb12 as a function of temperature (12- 300 K) were carried out, which gives more insight into the structural data of single and double-filled skutterudites. Our results show that due to the annealing treatment, a Sb deficiency is detectable and thus verifies defects at the Sb lattice site of the skutterudite. Furthermore, we show by electron microprobe analysis that a considerable amount of indium is lost duringmore » synthesis and post-processing for the single indium filled samples, but not for the double cerium and indium skutterudite sample. The double-filled skutterudite is superior to the single-filled skutterudite composition due to a higher charge carrier density, a comparable lattice thermal resistivity, and a higher density of states effective mass in our experiment. Finally, we obtained a significantly higher Einstein temperature for the double-filled skutterudite composition in comparison to the single-filled species, which reflects the high sensitivity due to filling of the void lattice position within the skutterudite crystal.« less

  7. Transmission of electronic effects through the {closo-1-CB9} and {closo-1-CB11} cages: apparent dissociation constants for series of [closo-1-CB9H8-1-COOH-10-X] and [closo-1-CB11H10-1-COOH-12-X] acids.

    PubMed

    Pecyna, Jacek G; Ringstrand, Bryan; Kaszyński, Piotr

    2012-05-01

    The apparent ionization constants pK(a)' for series of carboxylic acids [closo-1-CB(9)H(8)-1-COOH-10-X](-) (1) and [closo-1-CB(11)H(10)-1-COOH-12-X](-) (2), where X = H, I, n-C(6)H(13), (+)NMe(3), (+)N(2), (+)SMe(2), OC(5)H(11), were measured in EtOH/H(2)O (1/1, v/v) at 24 °C. Correlation analysis of the pK(a)' values using Hammett substituent constants σ(p)(X) gave the reaction constant ρ = 0.87 ± 0.04 for series 1 and ρ = 1.00 ± 0.09 for series 2. These values are higher than for derivatives of PhCH═CHCOOH (ρ = 0.70 ± 0.09 in 55% EtOH) and correspond to 56% and 65% efficiencies in transmission of electronic effects by [closo-1-CB(9)H(10)](-) (E) and [closo-1-CB(11)H(12)](-) (F), respectively, as compared to benzene (A). Experimental results were supported with DFT calculations of relative acidity for series of acids derived from A, E, and F in aqueous medium.

  8. Incommensurate Nuclear and Magnetic Structure of the Oxygen-Deficient Perovskites (Ba 2-3 xBi 3 x-1 )(Fe 2 xBi 1-2 x)O 2+3/2 x (0.43≤ x≤0.50)

    NASA Astrophysics Data System (ADS)

    Boullay, Ph.; Grebille, D.; Hervieu, M.; Raveau, B.; Suard, E.

    1999-11-01

    The actual nuclear and magnetic structures of the oxygen perovskites [Ba2-3xBi3x-1][Fe2xBi1-2x]O2+3x/2 (0.40

  9. Electronic structure of the metallic ground state of La{sub 2-2x}Sr{sub 1+2x}Mn{sub 2}O{sub 7} for x{approx} 0.59 and comparison with x=0.36, 0.38 compounds as revealed by angle-resolved photoemission.

    SciTech Connect

    Sun, Z.; Douglas, J. F.; Wang, Q.; Dessau, D. S.; Fedorov, A. V.; Lin, H.; Sahrakorpi, S.; Barbiellini, B.; Markiewicz, R. S.; Bansil, A.; Zheng, H.; Mitchell, J. F.; Materials Science Division; Univ. of Colorado; LBNL; Northeastern Univ.

    2008-01-01

    Using angle-resolved photoemission spectroscopy, we present the electronic structure of the metallic ground state of La{sub 2-2x}Sr{sub 1+2x}Mn{sub 2}O{sub 7} (x {approx} 0.59) and interpret the results in terms of first-principles band-structure computations, of which the generalized gradient approximation yields the best agreement with the experimental data. No bilayer-split bands are found in this compound, indicating the near degeneracy of electronic states in the neighboring MnO{sub 2} layers due to its A-type antiferromagnetic structure. The d{sub 3z{sup 2}-r{sup 2}} states near the zone center were not observed, which is also consistent with its A-type antiferromagnetic structure. Near the Fermi level, a kink in the dispersion reveals an important electron-phonon many-body interaction. The electron-phonon coupling is {approx}1 near the zone boundary and {approx}2 near the zone diagonal, showing strong k dependence.

  10. Excited states of154Nd studied through the decay of154Pr

    NASA Astrophysics Data System (ADS)

    Toh, Y.; Okano, K.; Taniguchi, A.; Yamada, S.; Kawase, Y.

    1996-12-01

    The neutron-rich isotope154Pr, the heaviest isotope of praseodymium, has been investigated by γ-ray multispectrum scaling and γ-γ-(t), X-γ-(t) coincidence experiments. The isotope154Pr was separated from235U fission products with the on-line isotope separator KUR-ISOL. The decay scheme of154Pr has been constructed consisting of 9 excited states and 12 transitions in154Nd, including 7 excited states newly found in the present experiment.

  11. Photoelectron spectrum of PrO{sup −}

    SciTech Connect

    Kafader, Jared O.; Ray, Manisha; Jarrold, Caroline Chick

    2015-08-14

    The photoelectron (PE) spectrum of PrO{sup −} exhibits a short 835 ± 20 cm{sup −1} vibrational progression of doublets (210 ± 30 cm{sup −1} splitting) assigned to transitions from the 4f{sup 2} [{sup 3}H{sub 4}] σ{sub 6s}{sup 2} Ω = 4 anion ground state to the 4f{sup 2} [{sup 3}H{sub 4}] σ{sub 6s} Ω = 3.5 and 4.5 neutral states. This assignment is analogous to that of the recently reported PE spectrum of CeO{sup −}, though the 82 cm{sup −1} splitting between the 4f [{sup 2}F{sub 2.5}] σ{sub 6s} Ω = 2 and Ω = 3 CeO neutral states could not be resolved [Ray et al., J. Chem. Phys. 142, 064305 (2015)]. The origin of the transition to the Ω = 3.5 neutral ground state is 0.96 ± 0.01 eV, which is the adiabatic electron affinity of PrO. Density functional theory calculations on the anion and neutral molecules support the assignment. The appearance of multiple, irregularly spaced and low-intensity features observed ca. 1 eV above the ground state cannot be reconciled with low-lying electronic states of PrO that are accessible via one-electron detachment. However, neutral states correlated with the 4f{sup 2} [{sup 3}H{sub 4}] 5d superconfiguration are predicted to be approximately 1 eV above the 4f{sup 2} [{sup 3}H{sub 4}] σ{sub 6s} Ω = 3.5 neutral ground state, leading to the assignment of these features to shake-up transitions to the excited neutral states. Based on tentative hot band transition assignments, the term energy of the previously unobserved 4f{sup 2} [{sup 3}H{sub 4}] σ{sub 6s} Ω = 2.5 neutral state is determined to be 1840 ± 110 cm{sup −1}.

  12. Electro-oxidation of ethanol on ternary non-alloyed Pt-Sn-Pr/C catalysts

    NASA Astrophysics Data System (ADS)

    Corradini, Patricia G.; Antolini, Ermete; Perez, Joelma

    2015-02-01

    Ternary Pt-Sn-Pr/C (70:10:20), (70:15:15) and (45:45:10) electro-catalysts were prepared by a modified formic acid method, and their activity for the ethanol oxidation reaction (EOR) was compared with that of Pt-Pr/C catalysts prepared by the same methods and that of commercial Pt-Sn/C (75:25) and Pt/C catalysts. Among all the catalysts, the Pt-Sn-Pr/C (45:45:10) catalyst presented both the highest mass activity and the highest specific activity. The steady state electrochemical stability of ternary Pt-Sn-Pr catalysts increased with the surface Sn/Pt atomic ratio. Following repetitive potential cycling (RPC), the activity for ethanol oxidation of Pt-Sn-Pr/C catalysts with high surface Sn/Pt atomic ratio was considerably higher than that of the corresponding as-prepared catalysts, and increased with increasing the Sn/Pt ratio. The increase of the EOR mass activity following RPC was ascribed to the increase of either the specific activity (for the Pt-Sn-Pr/C (70:15:15) catalyst) or the electrochemically active surface area (for the Pt-Sn-Pr/C (45:45:10) catalyst). Dissolution of Sn and Pr oxides from Pt-Sn-Pr/C catalyst surface was observed following RPC.

  13. Anomalous Schottky specific heat and structural distortion in ferromagnetic PrAl2.

    PubMed

    Pathak, Arjun K; Paudyal, D; Mudryk, Y; Gschneidner, K A; Pecharsky, V K

    2013-05-01

    Unique from other rare earth dialuminides, PrAl(2) undergoes a cubic to tetragonal distortion below T = 30 K in a zero magnetic field, but the system recovers its cubic symmetry upon the application of an external magnetic field of 10 kOe via a lifting of the 4f crystal field splitting. The nuclear Schottky specific heat in PrAl(2) is anomalously high compared to that of pure Pr metal. First principles calculations reveal that the 4f crystal field splitting in the tetragonally distorted phase of PrAl(2) underpins the observed unusual low temperature phenomena.

  14. Bayesian reconstruction of projection reconstruction NMR (PR-NMR).

    PubMed

    Yoon, Ji Won

    2014-11-01

    Projection reconstruction nuclear magnetic resonance (PR-NMR) is a technique for generating multidimensional NMR spectra. A small number of projections from lower-dimensional NMR spectra are used to reconstruct the multidimensional NMR spectra. In our previous work, it was shown that multidimensional NMR spectra are efficiently reconstructed using peak-by-peak based reversible jump Markov chain Monte Carlo (RJMCMC) algorithm. We propose an extended and generalized RJMCMC algorithm replacing a simple linear model with a linear mixed model to reconstruct close NMR spectra into true spectra. This statistical method generates samples in a Bayesian scheme. Our proposed algorithm is tested on a set of six projections derived from the three-dimensional 700 MHz HNCO spectrum of a protein HasA. PMID:25218584

  15. Magnetic excitations in single crystal PrNiSn

    NASA Astrophysics Data System (ADS)

    Beirne, E. D.; McEwen, K. A.; Habicht, K.; Fort, D.

    Inelastic neutron scattering results from a single crystal of the rare earth intermetallic PrNiSn are presented. Crystalline electric field excitations are found at 0.5, 2.4 and around 3.5 meV. The lower modes show little dispersion over q, but the 3.5 meV splits into two excitations, most clearly seen along the c* direction. Fitting the modes with gaussian functions allows us to show the pronounced dispersion to be of the form E(q)=E0+J1cos(qπ) for the upper mode, and E(q)=E0+J1cos(qπ)+J2cos(2qπ) for the lower mode. This suggests a longer range interaction for the lower mode. The lowest excitation at 0.5 meV confirms predictions made from previous measurements on polycrystalline samples that indicate a low lying CEF level.

  16. Beta Decay of 151Pr into Levels in 151Nd

    NASA Astrophysics Data System (ADS)

    Shibata, Michihiro; Ikuta, Tomohiko; Taniguchi, Akihiro; Osa, Akihiko; Tanaka, Akihiko; Yamamoto, Hiroshi; Kawade, Kiyoshi; Ruan, Jian-Zhi; Kawase, Yoichi; Okano, Kotoyuki

    1994-09-01

    The β-decay of 151 59Pr92 to the levels in 151 60Nd91 has been studied from the fission products of 235U using an on-line isotope separator (KUR-ISOL). Gamma-rays and conversion electrons have been measured. Conversion coefficients have been determined for the first time. The precise decay scheme is proposed up to 2430 keV. The newly observed 65 γ-rays and 16 levels are incorporated in it. The deduced level scheme of 151Nd was compared to the calculated level scheme on the basis of the rotation-vibration coupling model with a Nilsson potential. Low-lying levels were well reproduced by this model.

  17. Distribution of peripheral PrP(Sc) in sheep with naturally acquired scrapie.

    PubMed

    Garza, María Carmen; Monzón, Marta; Marín, Belén; Badiola, Juan José; Monleón, Eva

    2014-01-01

    Accumulation of prion protein (PrPSc) in the central nervous system is the hallmark of transmissible spongiform encephalopathies. However, in some of these diseases such as scrapie or chronic wasting disease, the PrPSc can also accumulate in other tissues, particularly in the lymphoreticular system. In recent years, PrPSc in organs other than nervous and lymphoid have been described, suggesting that distribution of this protein in affected individuals may be much larger than previously thought. In the present study, 11 non-nervous/non-lymphoid organs from 16 naturally scrapie infected sheep in advanced stages of the disease were examined for the presence of PrPSc. Fourteen infected sheep were of the ARQ/ARQ PRNP genotype and 2 of the VRQ/VRQ, where the letters A, R, Q, and V represent the codes for amino-acids alanine, arginine, glutamine and valine, respectively. Adrenal gland, pancreas, heart, skin, urinary bladder and mammary gland were positive for PrPSc by immunohistochemistry and IDEXX HerdChek scrapie/BSE Antigen EIA Test in at least one animal. Lung, liver, kidney and skeletal muscle exhibited PrPSc deposits by immunohistochemistry only. To our knowledge, this is the first report regarding the presence of PrPSc in the heart, pancreas and urinary bladder in naturally acquired scrapie infections. In some other organs examined, in which PrPSc had been previously detected, PrPSc immunolabeling was observed to be associated with new structures within those organs. The results of the present study illustrate a wide dissemination of PrPSc in both ARQ/ARQ and VRQ/VRQ infected sheep, even when the involvement of the lymphoreticular system is scarce or absent, thus highlighting the role of the peripheral nervous system in the spread of PrPSc.

  18. Distribution of Peripheral PrPSc in Sheep with Naturally Acquired Scrapie

    PubMed Central

    Garza, María Carmen; Monzón, Marta; Marín, Belén; Badiola, Juan José; Monleón, Eva

    2014-01-01

    Accumulation of prion protein (PrPSc) in the central nervous system is the hallmark of transmissible spongiform encephalopathies. However, in some of these diseases such as scrapie or chronic wasting disease, the PrPSc can also accumulate in other tissues, particularly in the lymphoreticular system. In recent years, PrPSc in organs other than nervous and lymphoid have been described, suggesting that distribution of this protein in affected individuals may be much larger than previously thought. In the present study, 11 non-nervous/non-lymphoid organs from 16 naturally scrapie infected sheep in advanced stages of the disease were examined for the presence of PrPSc. Fourteen infected sheep were of the ARQ/ARQ PRNP genotype and 2 of the VRQ/VRQ, where the letters A, R, Q, and V represent the codes for amino-acids alanine, arginine, glutamine and valine, respectively. Adrenal gland, pancreas, heart, skin, urinary bladder and mammary gland were positive for PrPSc by immunohistochemistry and IDEXX HerdChek scrapie/BSE Antigen EIA Test in at least one animal. Lung, liver, kidney and skeletal muscle exhibited PrPSc deposits by immunohistochemistry only. To our knowledge, this is the first report regarding the presence of PrPSc in the heart, pancreas and urinary bladder in naturally acquired scrapie infections. In some other organs examined, in which PrPSc had been previously detected, PrPSc immunolabeling was observed to be associated with new structures within those organs. The results of the present study illustrate a wide dissemination of PrPSc in both ARQ/ARQ and VRQ/VRQ infected sheep, even when the involvement of the lymphoreticular system is scarce or absent, thus highlighting the role of the peripheral nervous system in the spread of PrPSc. PMID:24828439

  19. Postdeposition annealing induced transition from hexagonal Pr{sub 2}O{sub 3} to cubic PrO{sub 2} films on Si(111)

    SciTech Connect

    Weisemoeller, T.; Bertram, F.; Gevers, S.; Greuling, A.; Deiter, C.; Tobergte, H.; Neumann, M.; Wollschlaeger, J.; Giussani, A.; Schroeder, T.

    2009-06-15

    Films of hexagonal praseodymium sesquioxide (h-Pr{sub 2}O{sub 3}) were deposited on Si(111) by molecular beam epitaxy and thereafter annealed in 1 atm oxygen at different temperatures, ranging from 100 to 700 deg. C. The films of the samples annealed at 300 deg. C or more were transformed to PrO{sub 2} with B-oriented Fm3m structure, while films annealed at lower temperatures kept the hexagonal structure. The films are composed of PrO{sub 2} and PrO{sub 2-d}elta species, which coexist laterally and are tetragonally distorted due to the interaction at the interface between oxide film and Si substrate. Compared to PrO{sub 2}, PrO{sub 2-d}elta has the same cubic structure but with oxygen vacancies. The oxygen vacancies are partly ordered and increase the vertical lattice constant of the film, whereas the lateral lattice constant is almost identical for both species and on all samples. The latter lattice constant matches the lattice constant of the originally crystallized hexagonal praseodymium sesquioxide. That means that no long range reordering of the praseodymium atoms takes place during the phase transformation.

  20. Salicylic acid induction-deficient mutants of Arabidopsis express PR-2 and PR-5 and accumulate high levels of camalexin after pathogen inoculation.

    PubMed Central

    Nawrath, C; Métraux, J P

    1999-01-01

    In Arabidopsis, systemic acquired resistance against pathogens has been associated with the accumulation of salicylic acid (SA) and the expression of the pathogenesis-related proteins PR-1, PR-2, and PR-5. We report here the isolation of two nonallelic mutants impaired in the pathway leading to SA biosynthesis. These SA induction-deficient (sid) mutants do not accumulate SA after pathogen inoculation and are more susceptible to both virulent and avirulent forms of Pseudomonas syringae and Peronospora parasitica. However, sid mutants are not as susceptible to these pathogens as are transgenic plants expressing the nahG gene encoding an SA hydroxylase that degrades SA to catechol. In contrast to NahG plants, only the expression of PR-1 is strongly reduced in sid mutants, whereas PR-2 and PR-5 are still expressed after pathogen attack. Furthermore, the accumulation of the phytoalexin camalexin is normal. These results indicate that SA-independent compensation pathways that do not operate in NahG plants are active in sid mutants. One of the mutants is allelic to eds5 (for enhanced disease susceptibility), whereas the other mutant has not been described previously. PMID:10449575

  1. Exotic (anti)ferrogmagnetism in Single Crystals of Pr6ni2Si3

    SciTech Connect

    Y. Janssen; K.W. Dennis; R. Prozorov; P.C. Canfield; R.W. McCallum

    2008-06-04

    The ternary intermetallic compound, Pr{sub 6}Ni{sub 2}Si{sub 3}, is a member of a structure series of compounds based on a triangular structure where the number of Pr atoms in the prism cross section can be systematically varied. Pr{sub 6}Ni{sub 2}Si{sub 3} contains two distinct Pr lattice sites which result in complex interactions between the magnetic ions. Extensive measurements of specific heat and magnetization on single-crystal samples indicate that Pr{sub 6}Ni{sub 2}Si{sub 3} orders with both a ferromagnet and an antiferromagnet component, with ordering temperatures of 39.6 and {approx}32 K, respectively. The ferromagnetic component c axis is accompanied by a large hysteresis, and the antiferromagnetic component c axis is accompanied by a spin-flop-type transition. More detailed measurements, of the vector magnetization, indicate that the ferromagnetic and the antiferromagnetic order appear independent of each other. These results not only clarify the behavior of Pr{sub 6}Ni{sub 2}Si{sub 3} itself but also of the other members of the structure series, Pr{sub 5}Ni{sub 2}Si{sub 3} and Pr{sub 15}Ni{sub 7}Si{sub 10}.

  2. 76 FR 17988 - Proposed Collection; Comment Request for Form SS-4 and SS-4PR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-31

    ... Internal Revenue Service Proposed Collection; Comment Request for Form SS-4 and SS-4PR AGENCY: Internal...(c)(2)(A)). Currently, the IRS is soliciting comments concerning Form SS-4, Application for Employer Identification Number, and Form SS- 4PR, Solicitud de Numero de Indentification Patronal (EIN). DATES:...

  3. 77 FR 43606 - Preliminary Damage Assessment for Individual Assistance Operations Manual (9327.2-PR)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-25

    ... Operations Manual (9327.2-PR) AGENCY: Federal Emergency Management Agency, DHS. ACTION: Notice of... Assessment for Individual Assistance Operations Manual (9327.2-PR). The Federal Emergency Management Agency..., 2011. DATES: This manual is effective July 18, 2012. ADDRESSES: This final manual is available...

  4. 76 FR 63628 - Preliminary Damage Assessment for Individual Assistance Operations Manual (9327.2-PR)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-13

    ... Operations Manual (9327.2-PR) AGENCY: Federal Emergency Management Agency, DHS. ACTION: Notice of... comments on the draft Preliminary Damage Assessment for Individual Assistance Operations Manual (9327.2-PR... proposed manual is not a rulemaking and the Federal Rulemaking Portal is being utilized only as a...

  5. 17 CFR Appendix C to Part 4 - Form CTA-PR

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 1 2014-04-01 2014-04-01 false Form CTA-PR C Appendix C to Part 4 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION COMMODITY POOL OPERATORS AND COMMODITY TRADING ADVISORS Pt. 4, App. C Appendix C to Part 4—Form CTA-PR ER24FE12.052...

  6. How to Make Big Improvements in the Small PR Shop. Revised.

    ERIC Educational Resources Information Center

    Moore, R. Keith, Comp.; Hunt, Susan, Ed.

    This guide for small public relations (PR) offices at colleges and universities includes sample job descriptions, information on PR duties and priorities, sample policy statements and operating guidelines, sample publicity materials, questionnaires, and internal forms for organization. Twenty-six tips on time management are provided in an article…

  7. Studies of two-center three-electron S...S bonds in [n-Pr{sub 2}S...Sn-Pr{sub 2}]{sup +} and [i-Pr{sub 2}S...Si-Pr{sub 2}]{sup +}: Thermochemistry of adduct formation and MS/MS metastable and collision-induced dissociation spectra of the adducts

    SciTech Connect

    James, M.A.; Illies, A.J.

    1996-09-26

    Gas-phase ion-molecule association reactions of n-propyl sulfide radical cation ([n-Pr{sub 2}S]{sup +}) with n-propyl sulfide (n-Pr{sub 2}S) were studied by equilibrium methods in CO{sub 2} bath gas to investigate the bond energy of the 2c-3e bond. The 2c-3e S...S bond enthalpy in [n-Pr{sub 2}S...Sn-Pr{sub 2}]{sup +} was determined to be 119 kJ/mol at 507 K. This results in a scaled S...S bond energy of 123 kJ/mol. The S...S bond enthalpy in the i-propyl sulfide dimer cation ([i-Pr{sub 2}S...Si-Pr{sub 2}]{sup +}) could not be determined due to a fragmentation reaction, the loss of an i-propyl group. MS/MS metastable and collision-induced dissociation experiments were carried out to determine metastable fragmentation pathways and to aid in structure analysis. The results are consistent with association products containing 2c-3e bonds; statistical unimolecular metastable fragmentation of the association adduct, [i-Pr{sub 2}S...Si-Pr{sub 2}]{sup +}, confirms the loss of the i-propyl group, which prevented the equilibrium experiments. 21 refs., 11 figs., 1 tab.

  8. PrE (Person-Relative-to-Event) Theory of Coping with Threat.

    ERIC Educational Resources Information Center

    Mulilis, John-Paul; Duval, T. Shelley

    The generalizability of Person-Relative-to-Event (PrE) theory, originally applied to disaster-related situations, is investigated in a non-disaster simulation. The PrE theory of coping with threat emphasizes the relationship between level of appraised threat relative to person resources and personal responsibility. This theory has previously been…

  9. Dynamic compressive behavior of Pr-Nd alloy at high strain rates and temperatures

    SciTech Connect

    Wang Huanran; Cai Canyuan; Chen Danian; Ma Dongfang

    2012-07-01

    Based on compressive tests, static on 810 material test system and dynamic on the first compressive loading in split Hopkinson pressure bar (SHPB) tests for Pr-Nd alloy cylinder specimens at high strain rates and temperatures, this study determined a J-C type [G. R. Johnson and W. H. Cook, in Proceedings of Seventh International Symposium on Ballistics (The Hague, The Netherlands, 1983), pp. 541-547] compressive constitutive equation of Pr-Nd alloy. It was recorded by a high speed camera that the Pr-Nd alloy cylinder specimens fractured during the first compressive loading in SHPB tests at high strain rates and temperatures. From high speed camera images, the critical strains of the dynamic shearing instability for Pr-Nd alloy in SHPB tests were determined, which were consistent with that estimated by using Batra and Wei's dynamic shearing instability criterion [R. C. Batra and Z. G. Wei, Int. J. Impact Eng. 34, 448 (2007)] and the determined compressive constitutive equation of Pr-Nd alloy. The transmitted and reflected pulses of SHPB tests for Pr-Nd alloy cylinder specimens computed with the determined compressive constitutive equation of Pr-Nd alloy and Batra and Wei's dynamic shearing instability criterion could be consistent with the experimental data. The fractured Pr-Nd alloy cylinder specimens of compressive tests were investigated by using 3D supper depth digital microscope and scanning electron microscope.

  10. 33 CFR 110.245 - Vieques Passage and Vieques Sound, near Vieques Island, P.R.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Vieques Passage and Vieques Sound, near Vieques Island, P.R. 110.245 Section 110.245 Navigation and Navigable Waters COAST GUARD... and Vieques Sound, near Vieques Island, P.R. (a) The anchorage grounds—(1) Vieques Passage...

  11. 33 CFR 110.245 - Vieques Passage and Vieques Sound, near Vieques Island, P.R.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Vieques Passage and Vieques Sound, near Vieques Island, P.R. 110.245 Section 110.245 Navigation and Navigable Waters COAST GUARD... and Vieques Sound, near Vieques Island, P.R. (a) The anchorage grounds—(1) Vieques Passage...

  12. 33 CFR 110.240 - San Juan Harbor, P.R.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false San Juan Harbor, P.R. 110.240 Section 110.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.240 San Juan Harbor, P.R. (a) The anchorage...

  13. 33 CFR 110.245 - Vieques Passage and Vieques Sound, near Vieques Island, P.R.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Vieques Passage and Vieques Sound, near Vieques Island, P.R. 110.245 Section 110.245 Navigation and Navigable Waters COAST GUARD... and Vieques Sound, near Vieques Island, P.R. (a) The anchorage grounds—(1) Vieques Passage...

  14. 33 CFR 110.240 - San Juan Harbor, P.R.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false San Juan Harbor, P.R. 110.240 Section 110.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.240 San Juan Harbor, P.R. (a) The anchorage...

  15. 33 CFR 110.240 - San Juan Harbor, P.R.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false San Juan Harbor, P.R. 110.240 Section 110.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.240 San Juan Harbor, P.R. (a) The anchorage...

  16. Identification of the Pr1 gene product completes the anthocyanin biosynthesis pathway of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In maize, mutations in the pr1 locus lead to the accumulation of pelargonidin (red) rather than cyanidin (purple) pigments in aleurone cells where the anthocyanin biosynthetic pathway is active. We characterized pr1 mutation and isolated a putative F3'H encoding gene (Zmf3'h1), and showed by segrega...

  17. PrBa{sub 2}Cu{sub 3}O{sub 7}: A new superconductor

    SciTech Connect

    Blackstead, H.A.; Dow, J.D.

    1995-10-01

    PrBa{sub 2}Cu{sub 3}O{sub 7} superconducts, provided Pr is kept off Ba-sites - experimentally confirming the prediction of the oxygen model and indicating that superconductivity originates in the chains, not in the planes.

  18. Proteinase K and the structure of PrPSc: The good, the bad and the ugly.

    PubMed

    Silva, Christopher J; Vázquez-Fernández, Ester; Onisko, Bruce; Requena, Jesús R

    2015-09-01

    Infectious proteins (prions) are, ironically, defined by their resistance to proteolytic digestion. A defining characteristic of the transmissible isoform of the prion protein (PrP(Sc)) is its partial resistance to proteinase K (PK) digestion. Diagnosis of prion disease typically relies upon immunodetection of PK-digested PrP(Sc) by Western blot, ELISA or immunohistochemical detection. PK digestion has also been used to detect differences in prion strains. Thus, PK has been a crucial tool to detect and, thereby, control the spread of prions. PK has also been used as a tool to probe the structure of PrP(Sc). Mass spectrometry and antibodies have been used to identify PK cleavage sites in PrP(Sc). These results have been used to identify the more accessible, flexible stretches connecting the β-strand components in PrP(Sc). These data, combined with physical constraints imposed by spectroscopic results, were used to propose a qualitative model for the structure of PrP(Sc). Assuming that PrP(Sc) is a four rung β-solenoid, we have threaded the PrP sequence to satisfy the PK proteolysis data and other experimental constraints.

  19. Stability of PrP**Sc from cattle inoculated with different BSE strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prion diseases are a class of transmissible neurodegenerative diseases, caused by an infectious protein, that afflict humans and other mammals. The infectious agent is a host encoded protein known as PrP that has adopted a misfolded conformation termed PrP**Sc. The diseases have been shown to manife...

  20. Synthetic scrapie infectivity: interaction between recombinant PrP and scrapie brain-derived RNA.

    PubMed

    Simoneau, Steve; Thomzig, Achim; Ruchoux, Marie-Madeleine; Vignier, Nicolas; Daus, Martin L; Poleggi, Anna; Lebon, Pierre; Freire, Sophie; Durand, Valerie; Graziano, Silvia; Galeno, Roberta; Cardone, Franco; Comoy, Emmanuel; Pocchiari, Maurizio; Beekes, Michael; Deslys, Jean-Philippe; Fournier, Jean-Guy

    2015-01-01

    The key molecular event in human cerebral proteinopathies, which include Alzheimer's, Parkinson's and Huntington's diseases, is the structural conversion of a specific host protein into a β-sheet-rich conformer. With regards to this common mechanism, it appears difficult to explain the outstanding infectious properties attributed to PrP(Sc), the hallmark of another intriguing family of cerebral proteinopathies known as transmissible spongiform encephalopathies (TSE) or prion diseases. The infectious PrP(Sc) or "prion" is thought to be composed solely of a misfolded form of the otherwise harmless cellular prion protein (PrP(c)). To gain insight into this unique situation, we used the 263K scrapie hamster model to search for a putative PrP(Sc)-associated factor that contributes to the infectivity of PrP(Sc) amyloid. In a rigorously controlled set of experiments that included several bioassays, we showed that originally innocuous recombinant prion protein (recPrP) equivalent to PrP(c) is capable of initiating prion disease in hamsters when it is converted to a prion-like conformation (β-sheet-rich) in the presence of RNA purified from scrapie-associated fibril (SAF) preparations. Analysis of the recPrP-RNA infectious mixture reveals the presence of 2 populations of small RNAs of approximately 27 and 55 nucleotides. These unprecedented findings are discussed in light of the distinct relationship that may exist between this RNA material and the 2 biological properties, infectivity and strain features, attributed to prion amyloid.

  1. Synthetic Scrapie Infectivity: Interaction between Recombinant PrP and Scrapie Brain-Derived RNA

    PubMed Central

    Simoneau, Steve; Thomzig, Achim; Ruchoux, Marie-Madeleine; Vignier, Nicolas; Daus, Martin L; Poleggi, Anna; Lebon, Pierre; Freire, Sophie; Durand, Valerie; Graziano, Silvia; Galeno, Roberta; Cardone, Franco; Comoy, Emmanuel; Pocchiari, Maurizio; Beekes, Michael; Deslys, Jean-Philippe; Fournier, Jean-Guy

    2015-01-01

    The key molecular event in human cerebral proteinopathies, which include Alzheimer's, Parkinson's and Huntington's diseases, is the structural conversion of a specific host protein into a β-sheet-rich conformer. With regards to this common mechanism, it appears difficult to explain the outstanding infectious properties attributed to PrPSc, the hallmark of another intriguing family of cerebral proteinopathies known as transmissible spongiform encephalopathies (TSE) or prion diseases. The infectious PrPSc or "prion" is thought to be composed solely of a misfolded form of the otherwise harmless cellular prion protein (PrPc). To gain insight into this unique situation, we used the 263K scrapie hamster model to search for a putative PrPSc-associated factor that contributes to the infectivity of PrPSc amyloid. In a rigorously controlled set of experiments that included several bioassays, we showed that originally innocuous recombinant prion protein (recPrP) equivalent to PrPc is capable of initiating prion disease in hamsters when it is converted to a prion-like conformation (β-sheet-rich) in the presence of RNA purified from scrapie-associated fibril (SAF) preparations. Analysis of the recPrP-RNA infectious mixture reveals the presence of 2 populations of small RNAs of approximately 27 and 55 nucleotides. These unprecedented findings are discussed in light of the distinct relationship that may exist between this RNA material and the 2 biological properties, infectivity and strain features, attributed to prion amyloid. PMID:25585171

  2. 33 CFR 110.240 - San Juan Harbor, P.R.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false San Juan Harbor, P.R. 110.240 Section 110.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.240 San Juan Harbor, P.R. (a) The anchorage...

  3. 33 CFR 110.240 - San Juan Harbor, P.R.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false San Juan Harbor, P.R. 110.240 Section 110.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.240 San Juan Harbor, P.R. (a) The anchorage...

  4. 33 CFR 110.74c - Bahia de San Juan, PR.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Bahia de San Juan, PR. 110.74c... ANCHORAGE REGULATIONS Special Anchorage Areas § 110.74c Bahia de San Juan, PR. The waters of San Antonio Channel, Bahia de San Juan, eastward of longitude 66°05′45″ W....

  5. 33 CFR 110.74c - Bahia de San Juan, PR.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bahia de San Juan, PR. 110.74c... ANCHORAGE REGULATIONS Special Anchorage Areas § 110.74c Bahia de San Juan, PR. The waters of San Antonio Channel, Bahia de San Juan, eastward of longitude 66°05′45″ W....

  6. Magnetic phase transitions in Pr(1-x)Lu(x)Mn(2)Ge(2) compounds.

    PubMed

    Wang, J L; Campbell, S J; Studer, A J; Avdeev, M; Zeng, R; Dou, S X

    2009-03-25

    The effects of replacing Pr by Lu on the magnetic behaviour and structures of Pr(1-x)Lu(x)Mn(2)Ge(2) (x = 0.2,x = 0.4) have been investigated using x-ray diffraction, Mössbauer spectroscopy, magnetization and neutron diffraction measurements. The substitution of Lu for Pr leads to a decrease in the lattice constants a, c and the unit cell volume V at room temperature with this contraction of the unit cell resulting in modifications of the Pr(1-x)Lu(x)Mn(2)Ge(2) magnetic structures. Four and five magnetic phase transitions-linked primarily with temperature driven changes in the intralayer Mn-Mn separation distances-have been detected within the temperature range 4.5-550 K for Pr(0.8)Lu(0.2)Mn(2)Ge(2) and Pr(0.6)Lu(0.4)Mn(2)Ge(2), respectively, with re-entrant ferromagnetism being detected around T(C)(Pr)∼31 K for Pr(0.6)Lu(0.4)Mn(2)Ge(2). It was found that T(C)(inter) and T(C)(Pr) increase with increasing applied field while T(N)(inter) decreases for Pr(0.6)Lu(0.4)Mn(2)Ge(2), indicating that the canted antiferromagnetic AFmc region contracts with increasing field. The Debye temperatures for Pr(1-x)Lu(x)Mn(2)Ge(2) with x = 0.2 and 0.4 were evaluated as θ(D) = 320 ± 40 K and θ(D) = 400 ± 20 K respectively from the temperature dependence of the average isomer shift. The magnetic structures of both compounds have been determined by means of neutron diffraction measurements over the temperature range 3-300 K with formation of the Fmi magnetic state below T(c/c) = 192 K for Pr(0.8)Lu(0.2)Mn(2)Ge(2) and the occurrence of re-entrant ferromagnetism below T(C)(Pr) = 31 K for Pr(0.6)Lu(0.4)Mn(2)Ge(2) being confirmed. PMID:21817459

  7. Inclusion of Trans Women in Pre-Exposure Phrophylaxis (PrEP): A Review

    PubMed Central

    Escudero, Daniel J; Kerr, Thomas; Operario, Don; Socías, Maria E; Sued, Omar; Marshall, Brandon DL

    2014-01-01

    Trans women are at high-risk of HIV infection. We conducted a review to determine the extent to which trans women were eligible for inclusion in and enrolled into pre-exposure prophylaxis (PrEP) efficacy trials. Out of seven trials analyzing PrEP efficacy, we found that trans women comprised only 1.2% of one trial, and 0.2% of total trial enrollments. Although an additional PrEP trial to determine efficacy among trans women may not be warranted, further research is needed to determine the effectiveness of PrEP in this marginalized population, through observational and feasibility studies. These studies should focus on unique barriers that trans women may experience while obtaining access to PrEP, such as gender discrimination, transphobia, and violence. PMID:25430940

  8. Effect of hydrogenation on magnetic and electronic behaviour of Pr-Ni

    SciTech Connect

    Rana, Pooja Singh, Sanjay K. Verma, U. P.

    2014-04-24

    Magnetic and electronic properties of PrNi and PrNi-H have been investigated by using first principles approach. The ground state of both the compounds is base-centered orthorhombic CrB structure. Calculations are performed using full potential linearized augmented plane wave plus local orbitals (FP-L/APW) method including spin-polarization within the frame work of density functional theory (DFT). The electronic exchange-correlation energy is described by generalized gradient approximation (GGA). The hydrogen stored in PrNi, i.e., PrNi-H has been studied to analyze the effective changes in magnetic moments and electronic structures in comparison to PrNi. A comparative study of the density of states in both the compounds has also been presented.

  9. Relative Yields of 149-153Pr in Spontaneous Fission of 252Cf

    NASA Astrophysics Data System (ADS)

    Eldridge, Jonathan; Wang, Enhong; Hwang, J. K.; Hamilton, Joe; Ramayya, A. V.; Luo, Y. X.; Rasmussen, J. O.; Zhu, S. J.; Liu, S. H.; Ter-Akopian, G. M.; Oganessian, Yu. Ts.

    2013-10-01

    The relative yields of the fission partners of 149-153Pr, resulting from the spontaneous fission of 252Cf, were studied. This study was done by means of γ - γ - γ , and γ - γ - γ - γ coincidence data taken in 2000 by the multi-HPGe, Compton-suppressed, gamma detector array, Gammasphere, at Lawrence Berkeley National Lab. The coincidence data were analyzed by double- and triple-gating on transitions in 149-153Pr and obtaining the intensities of the 93-101Y transitions. For 150 , 151 , 152 , 153Pr the 3n channel was found to be the strongest. The 149Pr, however, was found to peak at the 4n channel. These results were used to verify the assignments of the level schemes of 151 , 152 , 153Pr. The data are found to be in agreement with Wahl's independent yield tables.

  10. Amphoteric Doping of Praseodymium Pr3+ in SrTiO3 Grain Boundaries

    SciTech Connect

    Yang, Hao; Lee, H. S.; Kotula, Paul G.; Sato, Yukio; Ikuhara, Yuichi; Browning, Nigel D.

    2015-03-23

    Charge Compensation in rare-earth Praseodymium (Pr3+) doped SrTiO3 plays an important role in determining the overall photoluminescence properties of the system. Here, the Pr3+ doping behavior in SrTiO3 grain boundaries (GBs) is analyzed using aberration corrected scanning transmission electron microscopy (STEM). The presence of Pr3+ induces structure variations and changes the statistical prevalence of GB structures. In contrast to the assumption that Pr3+ substitutes for A site as expected in the bulk, Pr3+ is found to substitute both Sr and Ti sites inside GBs with the highest concentration in the Ti sites. This amphoteric doping behavior in the boundary plane is further confirmed by first principles theoretical calculations.

  11. Amphoteric doping of praseodymium Pr3+ in SrTiO3 grain boundaries

    DOE PAGES

    Yang, H.; Lee, H. S.; Kotula, P. G.; Sato, Y.; Ikuhara, Y.; Browning, N. D.

    2015-03-26

    Charge Compensation in rare-earth Praseodymium (Pr3+) doped SrTiO3 plays an important role in determining the overall photoluminescence properties of the system. Here, the Pr3+ doping behavior in SrTiO3 grain boundaries (GBs) is analyzed using aberration corrected scanning transmission electron microscopy (STEM). The presence of Pr3+ induces structure variations and changes the statistical prevalence of GB structures. In contrast to the assumption that Pr3+ substitutes for A site as expected in the bulk, Pr3+ is found to substitute both Sr and Ti sites inside GBs with the highest concentration in the Ti sites. As a result, this amphoteric doping behavior inmore » the boundary plane is further confirmed by first principles theoretical calculations.« less

  12. Inelastic neutron scttering study o fcrystal field levels in PrOs4As12

    SciTech Connect

    Chi, Songxue; Dai, Pengcheng; Barnes, Ted {F E }; Kang, H. J.; Lynn, J. W.; Ye, Feng; Maple, M. B.

    2008-01-01

    We use neutron scattering to study the Pr$^{3+}$ crystalline electric field (CEF) excitations in the filled skutterudite PrOs$_4$As$_{12}$. By comparing the observed levels and their strengths under neutron excitation with the theoretical spectrum and neutron excitation intensities, we identify the Pr$^{3+}$ CEF levels, and show that the ground state is a magnetic $\\Gamma_4^{(2)}$ triplet, and the excited states $\\Gamma_1$, $\\Gamma_4^{(1)}$ and $\\Gamma_{23}$ are at 0.4, 13 and 23~meV, respectively. A comparison of the observed CEF levels in PrOs$_4$As$_{12}$ with the heavy fermion superconductor PrOs$_4$Sb$_{12}$ reveals the microscopic origin of the differences in the ground states of these two filled skutterudites.

  13. TRMM/LIS and PR Observations and Thunderstorm Activity

    NASA Astrophysics Data System (ADS)

    Ohita, S.; Morimoto, T.; Kawasaki, Z. I.; Ushio, T.

    2005-12-01

    Thunderstorms observed by TRMM/PR and LIS have been investigating, and Lightning Research Group of Osaka University (LRG-OU) has unveiled several interesting features. Correlation between lightning activities and the snow depth of convective clouds may follow the power-five law. The power five law means that the flash density is a function of the snow-depth to power five. The definition of snow depth is the height of detectable cloud tops by TRMM/PR from the climatological freezing level, and it may be equivalent to the length of the portion where the solid phase precipitation particles exist. This is given by examining more than one million convective clouds, and we conclude that the power five law should be universal from the aspect of the statistic. Three thunderstorm active areas are well known as "Three World Chimneys", and those are the Central Africa, Amazon of the South America, and South East Asia. Thunderstorm activities in these areas are expected to contribute to the distribution of thermal energy around the equator to middle latitude regions. Moreover thunderstorm activity in the tropical region is believed to be related with the average temperature of our planet earth. That is why long term monitoring of lightning activity is required. After launching TRMM we have accumulated seven-year LIS observations, and statistics for three world chimneys are obtained. We have recognized the additional lightning active area, and that is around the Maracaibo lake in Venezuera. We conclude that this is because of geographical features of the Maracaibo lake and the continuous easterly trade wind. Lightning Activity during El Niño period is another interesting subject. LRGOU studies thunderstorm occurrences over west Indonesia and south China, and investigates the influence of El Nino on lightning . We compare the statistics between El Nino and non El Nino periods. We learn that the lightning activity during El Niño period is higher than non El Nino period instead

  14. Pr(III) luminescence enhancement by chelation in solution and in sol-gel glass

    NASA Astrophysics Data System (ADS)

    Zaitoun, M. A.; El-Qisairi, A. K.; Momani, K. A.; Qaseer, H. A.; Jaradat, Q. M.

    2015-02-01

    Due to the weak emission of lanthanide ions in solution, it is common practice to form complexes of the lanthanide ions with organic ligands that strongly absorbs light and transfers the energy to the lanthanide ion center via the antenna effect. The organic ligands 2-6-pyridinedicarboxylate (L1) and the polytonic diazine (N-N) ligand L2 (C22H16N12O2) were used to synthesize two Pr(III) complexes, namely: Pr-L1 (Na3[Pr(C7H3NO4)3]) and Pr-L2. The prepared complexes were further encapsulated in an optically transparent sol-gel glass. The synthesized ligands and complexes were characterized by FTIR and 1H NMR. Room temperature luminescence of Pr-L1 and Pr-L2 complexes in solution and in sol-gel glass were investigated using a spectrofluorometer. Excitation at the maximum absorption wavelength of the ligands (280 nm) resulted in the typical visible luminescence (centered at around 600 nm) resulting from the 1D2 → 3H4 transition of the Pr(III) ion, which contributes to the efficient energy transfer from the absorbing ligand L1 to the chelated Pr(III) ion (an antenna effect) while the Pr(III) luminescence is not efficiently sensitized by ligand L2. The obtained emission spectra indicated that the excitation energy level for the central Pr(III) is in a slightly lower location than ligand L1 excitation triplet (T1) level and can accept the energy transfer from T1 efficiently.

  15. Genetic and biochemical studies of the lipid-containing bacteriophage PR4

    SciTech Connect

    Vanden Boom, T.J.

    1989-01-01

    Bacteriophage PR4 is a lipid-containing bacterial virus able to infect Escherichia coli and Salmonella typhimurium. The icosahedral virion consists of an external protein capsid layer which surrounds a membrane vesicle enclosed ds DNA genome. The author has analyzed the time course of phage PR4 protein synthesis and have identified at least 34 proteins present in phage infected cells not detected in uninfected control cultures. In addition, he has isolated a more extensive set of conditional-lethal nonsense mutants of this virus. This collection of mutants permitted the identification of seven additional phage PR4 gene products, including the terminal genome protein and an accessory lytic factor. The present collection of phage PR4 mutants has been assigned to 19 distinct genetic groups on the basis of genetic complementation tests and sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of the proteins produced in mutant-infected UV-irradiated cells. A restriction endonuclease map of the phage PR4 genome was constructed which includes 59 sites for ten restriction endonucleases. In addition, he has constructed a collection of recombinant plasmids containing subgenomic DNA fragments of bacteriophage PR4. He has used this collection of plasmids to generate a physical-genetic map of the PR4 genome. The physical-genetic map localizes mutations in 13 phage PR4 genetic groups on the viral DNA molecule. To investigate the role of phosphatidylglycerol (PG) in phage assembly and infectivity, he propagated PR4 on an E. coli mutant defective in PG synthesis. The PG content of phage PR4 grown on the mutant host accounted for 0.4% of the total viral phospholipids, representing a 90-fold decrease in PG relative to the PG content of phage grown on a wild type host.

  16. A Truncated Progesterone Receptor (PR-M) Localizes to the Mitochondrion and Controls Cellular Respiration

    PubMed Central

    Dai, Qunsheng; Shah, Anish A.; Garde, Rachana V.; Yonish, Bryan A.; Zhang, Li; Medvitz, Neil A.; Miller, Sara E.; Hansen, Elizabeth L.; Dunn, Carrie N.

    2013-01-01

    The cDNA for a novel truncated progesterone receptor (PR-M) was previously cloned from human adipose and aortic cDNA libraries. The predicted protein sequence contains 16 unique N-terminal amino acids, encoded by a sequence in the distal third intron of the progesterone receptor PR gene, followed by the same amino acid sequence encoded by exons 4 through 8 of the nuclear PR. Thus, PR-M lacks the N terminus A/B domains and the C domain for DNA binding, whereas containing the hinge and hormone-binding domains. In this report, we have localized PR-M to mitochondria using immunofluorescent localization of a PR-M-green fluorescent protein (GFP) fusion protein and in Western blot analyses of purified human heart mitochondrial protein. Removal of the putative N-terminal mitochondrial localization signal obviated association of PR-M with mitochondria, whereas addition of the mitochondrial localization signal to green fluorescent protein resulted in mitochondrial localization. Immunoelectron microscopy and Western blot analysis after mitochondrial fractionation identified PR-M in the outer mitochondrial membrane. Antibody specificity was shown by mass spectrometry identification of a PR peptide in a mitochondrial membrane protein isolation. Cell models of overexpression and gene silencing of PR-M demonstrated a progestin-induced increase in mitochondrial membrane potential and an increase in oxygen consumption consistent with an increase in cellular respiration. This is the first example of a truncated steroid receptor, lacking a DNA-binding domain that localizes to the mitochondrion and initiates direct non-nuclear progesterone action. We hypothesize that progesterone may directly affect cellular energy production to meet the increased metabolic demands of pregnancy. PMID:23518922

  17. S1PR1-mediated IFNAR1 degradation modulates plasmacytoid dendritic cell interferon-α autoamplification

    PubMed Central

    Teijaro, John R.; Studer, Sean; Leaf, Nora; Kiosses, William B.; Nguyen, Nhan; Matsuki, Kosuke; Negishi, Hideo; Taniguchi, Tadatsugu; Oldstone, Michael B. A.; Rosen, Hugh

    2016-01-01

    Blunting immunopathology without abolishing host defense is the foundation for safe and effective modulation of infectious and autoimmune diseases. Sphingosine 1-phosphate receptor 1 (S1PR1) agonists are effective in treating infectious and multiple autoimmune pathologies; however, mechanisms underlying their clinical efficacy are yet to be fully elucidated. Here, we uncover an unexpected mechanism of convergence between S1PR1 and interferon alpha receptor 1 (IFNAR1) signaling pathways. Activation of S1PR1 signaling by pharmacological tools or endogenous ligand sphingosine-1 phosphate (S1P) inhibits type 1 IFN responses that exacerbate numerous pathogenic conditions. Mechanistically, S1PR1 selectively suppresses the type I IFN autoamplification loop in plasmacytoid dendritic cells (pDCs), a specialized DC subset, for robust type I IFN release. S1PR1 agonist suppression is pertussis toxin-resistant, but inhibited by an S1PR1 C-terminal–derived transactivating transcriptional activator (Tat)-fusion peptide that blocks receptor internalization. S1PR1 agonist treatment accelerates turnover of IFNAR1, suppresses signal transducer and activator of transcription 1 (STAT1) phosphorylation, and down-modulates total STAT1 levels, thereby inactivating the autoamplification loop. Inhibition of S1P-S1PR1 signaling in vivo using the selective antagonist Ex26 significantly elevates IFN-α production in response to CpG-A. Thus, multiple lines of evidence demonstrate that S1PR1 signaling sets the sensitivity of pDC amplification of IFN responses, thereby blunting pathogenic immune responses. These data illustrate a lipid G-protein coupled receptor (GPCR)-IFNAR1 regulatory loop that balances effective and detrimental immune responses and elevated endogenous S1PR1 signaling. This mechanism will likely be advantageous in individuals subject to a range of inflammatory conditions. PMID:26787880

  18. Pr(III) luminescence enhancement by chelation in solution and in sol-gel glass.

    PubMed

    Zaitoun, M A; El-Qisairi, A K; Momani, K A; Qaseer, H A; Jaradat, Q M

    2015-02-01

    Due to the weak emission of lanthanide ions in solution, it is common practice to form complexes of the lanthanide ions with organic ligands that strongly absorbs light and transfers the energy to the lanthanide ion center via the antenna effect. The organic ligands 2-6-pyridinedicarboxylate (L1) and the polytonic diazine (N-N) ligand L2 (C22H16N12O2) were used to synthesize two Pr(III) complexes, namely: Pr-L1 (Na3[Pr(C7H3NO4)3]) and Pr-L2. The prepared complexes were further encapsulated in an optically transparent sol-gel glass. The synthesized ligands and complexes were characterized by FTIR and (1)H NMR. Room temperature luminescence of Pr-L1 and Pr-L2 complexes in solution and in sol-gel glass were investigated using a spectrofluorometer. Excitation at the maximum absorption wavelength of the ligands (280nm) resulted in the typical visible luminescence (centered at around 600nm) resulting from the (1)D2→(3)H4 transition of the Pr(III) ion, which contributes to the efficient energy transfer from the absorbing ligand L1 to the chelated Pr(III) ion (an antenna effect) while the Pr(III) luminescence is not efficiently sensitized by ligand L2. The obtained emission spectra indicated that the excitation energy level for the central Pr(III) is in a slightly lower location than ligand L1 excitation triplet (T1) level and can accept the energy transfer from T1 efficiently. PMID:25467665

  19. Reactivity against Complementary Proteinase-3 Is Not Increased in Patients with PR3-ANCA-Associated Vasculitis

    PubMed Central

    Tadema, Henko; Kallenberg, Cees G. M.; Stegeman, Coen A.; Heeringa, Peter

    2011-01-01

    The etiology of anti-neutrophil cytoplasmic antibodies (ANCA) associated vasculitides (AAV) is unknown, but the association between infections and autoimmunity has been studied extensively. In 2004, a novel theory was proposed that could link infection and autoimmunity. This ‘theory of autoantigen complementarity’ was based on the serendipitous finding of antibodies against complementary-PR3 (cPR3) in patients with PR3-ANCA-associated vasculitis. cPR3 demonstrated homology to several bacterial proteins, and it was hypothesized that PR3-ANCA develop in response to anti-cPR3 antibodies, as a consequence of the anti-idiotypic network. These data have not been confirmed in other patient cohorts. We investigated the presence of anti-cPR3 antibodies in a Dutch cohort of PR3-ANCA-associated vasculitis patients. Anti-cPR3 reactivity was determined in serum using ELISA. Two separate batches of cPR3 were used to determine reactivity in two separate cohorts of PR3-ANCA-associated vasculitis patients. We found that anti-cPR3-reactivity was not increased in our PR3-ANCA-associated vasculitis patients, in comparison to control groups. Further research will be necessary to prove the concept of autoantigen complementarity in autoimmune diseases. PMID:21437233

  20. Temperature-dependent segregation of Pr{sup 3+} impurity ions in Y{sub 2}SiO{sub 5}:Pr{sup 3+} and YPO{sub 4}:Pr{sup 3+} nanocrystals

    SciTech Connect

    Znamenskii, N. V.; Maksimchuk, P. O.; Malyukin, Yu. V.; Masalov, A. A.; Semin'ko, V. V.; Shashkov, A. Yu.

    2013-04-15

    Stationary and time-resolved spectroscopic methods are used to show that the impurity ions in Y{sub 2}SiO{sub 5}:Pr{sup 3+} and YPO{sub 4}:Pr{sup 3+} nanocrystals are distributed nonuniformly. This nonuniform distribution is found to be caused by the temperature-dependent segregation of Pr{sup 3+} ions near the surface of a nanocrystal. The motion of the activator ions from the bulk of a nanocrystal to the near-surface layer is traced when the activator concentration and the heat-treatment parameters are varied over wide ranges, and the main parameters of this effect (impurity redistribution intensity and time, diffusion coefficient) are estimated.

  1. Type II Secretion-Dependent Degradative and Cytotoxic Activities Mediated by Stenotrophomonas maltophilia Serine Proteases StmPr1 and StmPr2

    PubMed Central

    DuMont, Ashley L.; Karaba, Sara M.

    2015-01-01

    Stenotrophomonas maltophilia is an emerging opportunistic pathogen that primarily causes pneumonia and bacteremia in immunocompromised individuals. We recently reported that S. maltophilia strain K279a encodes the Xps type II secretion system and that Xps promotes rounding, actin rearrangement, detachment, and death in the human lung epithelial cell line A549. Here, we show that Xps-dependent cell rounding and detachment occur with multiple human and murine cell lines and that serine protease inhibitors block Xps-mediated rounding and detachment of A549 cells. Using genetic analysis, we determined that the serine proteases StmPr1 and StmPr2, which were confirmed to be Xps substrates, are predominantly responsible for secreted proteolytic activities exhibited by strain K279a, as well as the morphological and cytotoxic effects on A549 cells. Supernatants from strain K279a also promoted the degradation of type I collagen, fibrinogen, and fibronectin in a predominantly Xps- and protease-dependent manner, although some Xps-independent degradation of fibrinogen was observed. Finally, Xps, and predominantly StmPr1, degraded interleukin 8 (IL-8) secreted by A549 cells during coculture with strain K279a. Our findings indicate that while StmPr1 and StmPr2 are predominantly responsible for A549 cell rounding, extracellular matrix protein degradation, and IL-8 degradation, additional Xps substrates also contribute to these activities. Altogether, our data provide new insight into the virulence potential of the S. maltophilia Xps type II secretion system and its StmPr1 and StmPr2 substrates. PMID:26169274

  2. Molecular Characteristics and Biochemical Functions of VpPR10s from Vitis pseudoreticulata Associated with Biotic and Abiotic Stresses

    PubMed Central

    Wang, Lan; Wei, Jinyu; Zou, Ying; Xu, Keyao; Wang, Yuejin; Cui, Lu; Xu, Yan

    2014-01-01

    Grapes are one of the world’s oldest and most important fruit crops. They are of high economic value in many countries, but the susceptibility of the dominant winegrape species Vitis vinifera to fungal disease is a significant problem. The Chinese wild grape species are a rich source of disease-resistance genes and these can be used to discover how disease resistance in V. vinifera grapevines might be enhanced. Pathogenesis-related (PR) 10 proteins are involved in the disease-response. Here, we use the genomic DNA of the Chinese wild species Vitis pseudoreticulata accession “Baihe-35-1” as the template to design specific primers based on VvPR10s sequences. We used overlap extension PCR to obtain the sequences: VpPR10.4, VpPR10.6, VpPR10.7 and VpPR10.9. The coding sequences of the VpPR10s were then cloned into the pGEX-4T-1 vector. The purified proteins VpPR10.4, VpPR10.6, VpPR10.7 and VpPR10.9 were used to analyse nuclease activity. Meanwhile, functional analysis of VpPR10s under different biotic and abiotic stresses was carried out to further clarify the disease-resistance mechanisms of the Chinese wild grapevine VpPR10 genes. The analysis of protein structure indicates that VpPR10.4 and VpPR10.7 had the P-loop domain and the Bet v 1 motif, which are a consistent feature of plant PR10. However, there was no P-loop domain or Bet v 1 motif in VpPR10.9 and we could not find the Bet v 1 motif in VpPR10.6. The results of the nuclease activity assay and of the functional analyses of VpPR10s under different biotic and abiotic stresses also confirm that VpPR10.4 and VpPR10.7 proteins have marked RNase, DNase, anti-fungal activities and respond to abiotic stresses. The VpPR10.6 and VpPR10.9 proteins do not have these activities and functions. PMID:25340981

  3. Magnetic and transport properties of PrRhSi3.

    PubMed

    Anand, V K; Adroja, D T; Hillier, A D

    2013-05-15

    We have investigated the magnetic and transport properties of a noncentrosymmetric compound PrRhSi3 by dc magnetic susceptibility χ(T), isothermal magnetization M(H), thermoremanent magnetization M(t), specific heat Cp(T), electrical resistivity ρ(T,H) and muon spin relaxation (μSR) measurements. At low fields χ(T) shows two anomalies near 15 and 7 K with an irreversibility between ZFC and FC data below 15 K. In contrast, no anomaly is observed in Cp(T) or ρ(T) data. M(H) data at 2 K exhibit very sharp increase below 0.5 T and a weak hysteresis. M(t) exhibits very slow relaxation, typical for a spin-glass system. Even though the absence of any anomaly in Cp(T) is consistent with the spin-glass type behavior, there is no obvious origin of spin-glass behavior in this structurally well ordered compound. The crystal electric field (CEF) analysis of Cp(T) data indicates a CEF-split singlet ground state lying below a doublet at 81(1) K and a quasi-triplet at 152(2) K. The ρ(T) data indicate a metallic behavior, and ρ(H) exhibits a very high positive magnetoresistance, as high as ~300% in 9 T at 2 K. No long range magnetic order or spin-glass behavior was detected in a μSR experiment down to 1.2 K.

  4. Dielectric relaxation of PrFeO3 nanoparticles

    NASA Astrophysics Data System (ADS)

    Saha, Sujoy; Chanda, Sadhan; Dutta, Alo; Sinha, T. P.

    2016-08-01

    PrFeO3 (PFO) nanoceramic is synthesized by a sol-gel reaction technique. Thermogravimetric study of the as prepared gel is performed to get the lowest possible calcination temperature of PFO nanoparticles. The Rietveld refinement of the powder X-ray diffraction (XRD) pattern shows that the sample crystallizes in the orthorhombic (Pnma) phase at room temperature. The particle size of the sample is determined by scanning electron microscopy. The vibrational properties of the samples are studied by Raman spectroscopy at an excitation wavelength of 488 nm to substantiate the XRD results. Group-theoretical study is performed to assign the different vibrational modes of the sample in accordance with structural symmetry. Dielectric spectroscopy is applied to investigate the ac electrical properties of PFO at various temperatures between 313 and 473 K and in a frequency range of 42 Hz-1.1 MHz. The modified Cole-Cole equation is used to describe the experimental dielectric spectra. The frequency-dependent conductivity spectra are found to follow the power law. The temperature dependent dc conductivity is found to obey the Arrhenius law with an activation energy of 0.280 eV. An analysis of the real and imaginary parts of impedance is performed, assuming a distribution of relaxation times as confirmed by Cole-Cole plot.

  5. Promiscuous 2-aminothiazoles (PrATs): a frequent hitting scaffold.

    PubMed

    Devine, Shane M; Mulcair, Mark D; Debono, Cael O; Leung, Eleanor W W; Nissink, J Willem M; Lim, San Sui; Chandrashekaran, Indu R; Vazirani, Mansha; Mohanty, Biswaranjan; Simpson, Jamie S; Baell, Jonathan B; Scammells, Peter J; Norton, Raymond S; Scanlon, Martin J

    2015-02-12

    We have identified a class of molecules, known as 2-aminothiazoles (2-ATs), as frequent-hitting fragments in biophysical binding assays. This was exemplified by 4-phenylthiazol-2-amine being identified as a hit in 14/14 screens against a diverse range of protein targets, suggesting that this scaffold is a poor starting point for fragment-based drug discovery. This prompted us to analyze this scaffold in the context of an academic fragment library used for fragment-based drug discovery (FBDD) and two larger compound libraries used for high-throughput screening (HTS). This analysis revealed that such "promiscuous 2-aminothiazoles" (PrATs) behaved as frequent hitters under both FBDD and HTS settings, although the problem was more pronounced in the fragment-based studies. As 2-ATs are present in known drugs, they cannot necessarily be deemed undesirable, but the combination of their promiscuity and difficulties associated with optimizing them into a lead compound makes them, in our opinion, poor scaffolds for fragment libraries. PMID:25559643

  6. Expression analysis of a plum pathogenesis related 10 (PR10) protein during brown rot infection.

    PubMed

    El-kereamy, Ashraf; Jayasankar, S; Taheri, Ali; Errampalli, Deena; Paliyath, Gopinadhan

    2009-01-01

    Plant PR10 is one of the pathogenesis related proteins, induced upon exposure to different stress conditions including fungal infection. PR10 proteins have been implicated in fungal disease resistance in some species; however its transcriptional regulation is not well understood. In the present work we cloned a PR10 gene from European plums (Prunus domestica L.) and monitored the quantitative changes in its transcript levels as a result of fungal infection in two varieties. We also studied the possible involvement of the membrane degrading enzyme phospholipase D-alpha (PLDalpha). In the susceptible variety, 'Veeblue', infection with the brown rot fungus Monilinia fructicola induced PLDalpha and PR10 expression, while in the resistant variety, 'Violette', a constitutive expression of PLDalpha and PR10 transcripts levels were observed. Resistance to M. fructicola also coincides with a sharp decrease in the expression of ABI1, a protein phosphatase and elevated hydrogen peroxide content after infection. Further, inhibition of PLDalpha by hexanal treatment, up-regulated ABI1 and decreased PR10 expression, suggesting a possible relationship between the two. We further confirm these results in Arabidopsis abi1 mutant that shows a higher level of PR10 transcripts.

  7. Radioprotective Effect of Aminothiol PrC-210 on Irradiated Inner Ear of Guinea Pig.

    PubMed

    Giese, Arnaud P J; Guarnaschelli, Jess G; Ward, Jonette A; Choo, Daniel I; Riazuddin, Saima; Ahmed, Zubair M

    2015-01-01

    Radiotherapy of individuals suffering with head & neck or brain tumors subserve the risk of sensorineural hearing loss. Here, we evaluated the protective effect of Aminothiol PrC-210 (3-(methyl-amino)-2-((methylamino)methyl)propane-1-thiol) on the irradiated inner ear of guinea pigs. An intra-peritoneal or intra-tympanic dose of PrC-210 was administered prior to receiving a dose of gamma radiation (3000 cGy) to each ear. Auditory Brainstem Responses (ABRs) were recorded one week and two weeks after the radiation and compared with the sham animal group. ABR thresholds of guinea pigs that received an intra-peritoneal dose of PrC-210 were significantly better compared to the non-treated, control animals at one week post-radiation. Morphologic analysis of the inner ear revealed significant inflammation and degeneration of the spiral ganglion in the irradiated animals not treated with PrC-210. In contrast, when treated with PrC-210 the radiation effect and injury to the spiral ganglion was significantly alleviated. PrC-210 had no apparent cytotoxic effect in vivo and did not affect the morphology or count of cochlear hair cells. These findings suggest that aminothiol PrC-210 attenuated radiation-induced cochlea damage for at least one week and protected hearing. PMID:26599238

  8. Generation and characterization of a monoclonal antibody against prM protein of West Nile virus.

    PubMed

    Guo, Li-Ping; Huo, Hong; Wang, Xiao-Lei; Bu, Zhi-Gao; Hua, Rong-Hong

    2014-12-01

    West Nile virus (WNV), which is an emerging pathogenic flavivirus with increasing distribution worldwide, is the cause of major human and animal health concerns. The pre-membrane (prM) protein of WNV is cleaved during maturation by the furin protease into the structural protein M and a pr-segment. In this study we generated and characterized a monoclonal antibody (MAb) against the WNV prM protein. Western blot analysis showed that the MAb reacted with WNV prM specifically. Immunohistochemistry assays demonstrated that the MAb recognized native prM protein in transfected BHK-21 cells. Preliminary studies were performed to identify the epitope recognized by the MAb using a set of synthesized overlapping peptides spanning the whole length of the prM protein. The MAb reported here may provide a valuable tool for the further exploration of the biological properties and functions of the prM protein and may also be developed for potential clinical applications. PMID:25514166

  9. Occurrence of Neuroblastoma among TP53 p.R337H Carriers

    PubMed Central

    Mastellaro, Maria José; Cardinalli, Izilda Aparecida; Zambaldi, Lilian Girotto; Aguiar, Simone Santos; Yunes, José Andrés

    2015-01-01

    The high incidence of adrenocortical tumors and choroid plexus carcinoma in children from South and Southeastern regions of Brazil is associated with the germline p.R337H mutation of TP53 gene. The concomitant occurrence of neuroblastoma and adrenocortical tumors in pediatric patients harboring the p.R337H mutation at our institution prompted us to investigate the putative association between p.R337H and pediatric neuroblastoma. Genomic DNA samples from 83 neuroblastoma patients referred to a single institution during the period of 2000–2014 were screened for the p.R337H mutation. Available samples from carriers were investigated for both nuclear p53 accumulation and loss of heterozigosity in tumor. Clinical data were obtained from medical records in order to assess the impact of 337H allele on manifestation of the disease. Seven out 83 neuroblastoma patients (8.4%) were carriers of the TP53 p.R337H mutation in our cohort. Immunohistochemical analysis of p.R337H-positive tumors revealed nuclear p53 accumulation. Loss of heterozigosity was not found among available samples. The presence of 337H allele was associated with increased proportion of stage I tumors. Our data indicate that in addition to adrenocortical tumors, choroid plexus carcinoma, breast cancer and osteosarcoma, genetic counseling and clinical surveillance should consider neuroblastoma as a potential neoplasia affecting p.R337H carriers. PMID:26452166

  10. New Pr3+ site in β-SiAlON red phosphor

    NASA Astrophysics Data System (ADS)

    Lazarowska, Agata; Mahlik, Sebastian; Grinberg, Marek; Liu, Tzu-Chen; Liu, Ru-Shi

    2013-09-01

    Luminescent emission spectra and excitation spectra of Pr0.016Si5.9Al0.1O0.1N7.9 (β-SiAlON:Pr3+) were measured. Emission upon UV excitation consists of sharp lines peaked between 600 and 630 nm, related to the 1D2→3H4 and 3P0→3H6 transitions in Pr3+ ion. Two other group of lines peaked between 500 and 530 nm and between 640 and 680 nm are related to the 3P0→3H4 and 3P0→3FJ transitions, respectively. Excitation spectrum of the β-SiAlON:Pr3+ luminescence (observed at 641 nm and at 632 nm) consists of sharp lines in the spectral region 450-500 nm related to the 3H4→3P0, 3P1, 3P2 transitions and two broad bands peaked at 280 and 330 nm attributed to ionization of Pr3+. Emission obtained upon excitation at 330 nm band contains additional peaks besides earlier observed upon excitation at 280 nm band and under excitation in the 3H4→3P2 absorption region. These additional lines were attributed to the second site of Pr3+ (Wyckoff letter 2a) where Pr3+ ions occupy the interstitial positions of nine-fold coordinated by nitrogen/oxygen ions.

  11. Radioprotective Effect of Aminothiol PrC-210 on Irradiated Inner Ear of Guinea Pig.

    PubMed

    Giese, Arnaud P J; Guarnaschelli, Jess G; Ward, Jonette A; Choo, Daniel I; Riazuddin, Saima; Ahmed, Zubair M

    2015-01-01

    Radiotherapy of individuals suffering with head & neck or brain tumors subserve the risk of sensorineural hearing loss. Here, we evaluated the protective effect of Aminothiol PrC-210 (3-(methyl-amino)-2-((methylamino)methyl)propane-1-thiol) on the irradiated inner ear of guinea pigs. An intra-peritoneal or intra-tympanic dose of PrC-210 was administered prior to receiving a dose of gamma radiation (3000 cGy) to each ear. Auditory Brainstem Responses (ABRs) were recorded one week and two weeks after the radiation and compared with the sham animal group. ABR thresholds of guinea pigs that received an intra-peritoneal dose of PrC-210 were significantly better compared to the non-treated, control animals at one week post-radiation. Morphologic analysis of the inner ear revealed significant inflammation and degeneration of the spiral ganglion in the irradiated animals not treated with PrC-210. In contrast, when treated with PrC-210 the radiation effect and injury to the spiral ganglion was significantly alleviated. PrC-210 had no apparent cytotoxic effect in vivo and did not affect the morphology or count of cochlear hair cells. These findings suggest that aminothiol PrC-210 attenuated radiation-induced cochlea damage for at least one week and protected hearing.

  12. PrEP as Peri-conception HIV Prevention for Women and Men.

    PubMed

    Heffron, Renee; Pintye, Jillian; Matthews, Lynn T; Weber, Shannon; Mugo, Nelly

    2016-06-01

    Daily oral tenofovir (TDF)-based pre-exposure prophylaxis (PrEP) is an effective HIV prevention strategy and recommended for men and women with substantial risk of HIV acquisition. The peri-conception period, the stage prior to pregnancy when condom use is necessarily reduced, has elevated HIV risk that can be mitigated by PrEP use. Data from a randomized trial suggest that peri-conception PrEP use by HIV-seronegative women does not increase the risk of pregnancy loss, birth defects or congenital anomalies, preterm birth, or infant growth faltering. Women considering PrEP use throughout pregnancy must weigh the known increased risk of HIV acquisition with unknown risks of drug effects on infant growth. PrEP has been used safely by HIV-seronegative men with HIV-seropositive female partners who have become pregnant. As an effective user-controlled HIV prevention strategy, PrEP offers autonomy and empowerment for HIV prevention and can be recommended alongside antiretroviral therapy, fertility screening, vaginal self-insemination, intercourse timed to peak fertility, medically assisted reproduction, and other safer conception strategies to provide multiple options. The integration of PrEP into safer conception programs is warranted and will safely reduce HIV transmission to women, men, and children during the peri-conception period.

  13. Acetylcholinesterase triggers the aggregation of PrP 106-126

    SciTech Connect

    Pera, M.; Roman, S.; Ratia, M.; Camps, P.; Munoz-Torrero, D.; Colombo, L.; Manzoni, C.; Salmona, M.; Badia, A.; Clos, M.V. . E-mail: Victoria.Clos@uab.es

    2006-07-21

    Acetylcholinesterase (AChE), a senile plaque component, promotes amyloid-{beta}-protein (A{beta}) fibril formation in vitro. The presence of prion protein (PrP) in Alzheimer's disease (AD) senile plaques prompted us to assess if AChE could trigger the PrP peptides aggregation as well. Consequently, the efficacy of AChE on the PrP peptide spanning-residues 106-126 aggregation containing a coumarin fluorescence probe (coumarin-PrP 106-126) was studied. Kinetics of coumarin-PrP 106-126 aggregation showed a significant increase of maximum size of aggregates (MSA), which was dependent on AChE concentration. AChE-PrP 106-126 aggregates showed the tinctorial and optical amyloid properties as determined by polarized light and electronic microscopy analysis. A remarkable inhibition of MSA was obtained with propidium iodide, suggesting that AChE triggers PrP 106-126 and A{beta} aggregation through a similar mechanism. Huprines (AChE inhibitors) also significantly decreased MSA induced by AChE as well, unveiling the potential interest for some AChE inhibitors as a novel class of potential anti-prion drugs.

  14. UV-B-Induced PR-1 Accumulation Is Mediated by Active Oxygen Species.

    PubMed

    Green, R.; Fluhr, R.

    1995-02-01

    Depletion of the stratospheric ozone layer may result in an increase in the levels of potentially harmful UV-B radiation reaching the surface of the earth. We have found that UV-B is a potent inducer of the plant pathogenesis-related protein PR-1 in tobacco leaves. UV-B fluences required for PR-1 accumulation are similar to those of other UV-B-induced responses. The UV-B-induced PR-1 accumulation was confined precisely to the irradiated area of the leaf but displayed no leaf tissue specificity. A study of some of the possible components of the signal transduction pathway between UV-B and PR-1 induction showed that photosynthetic processes are not essential, and photoreversible DNA damage is not involved. Antioxidants and cycloheximide were able to block the induction of PR-1 by UV-B, and treatment of leaves with a generator of reactive oxygen resulted in the accumulation of PR-1 protein. These results demonstrate an absolute requirement for active oxygen species and protein synthesis in this UV-B signal transduction pathway. In contrast, we also show that other elicitors, notably salicylic acid, are able to elicit PR-1 via nonreactive oxygen species-requiring pathways.

  15. Hypothalamic S1P/S1PR1 axis controls energy homeostasis.

    PubMed

    Silva, Vagner R R; Micheletti, Thayana O; Pimentel, Gustavo D; Katashima, Carlos K; Lenhare, Luciene; Morari, Joseane; Mendes, Maria Carolina S; Razolli, Daniela S; Rocha, Guilherme Z; de Souza, Claudio T; Ryu, Dongryeol; Prada, Patrícia O; Velloso, Lício A; Carvalheira, José B C; Pauli, José Rodrigo; Cintra, Dennys E; Ropelle, Eduardo R

    2014-01-01

    Sphingosine 1-phosphate receptor 1 (S1PR1) is a G-protein-coupled receptor for sphingosine-1-phosphate (S1P) that has a role in many physiological and pathophysiological processes. Here we show that the S1P/S1PR1 signalling pathway in hypothalamic neurons regulates energy homeostasis in rodents. We demonstrate that S1PR1 protein is highly enriched in hypothalamic POMC neurons of rats. Intracerebroventricular injections of the bioactive lipid, S1P, reduce food consumption and increase rat energy expenditure through persistent activation of STAT3 and the melanocortin system. Similarly, the selective disruption of hypothalamic S1PR1 increases food intake and reduces the respiratory exchange ratio. We further show that STAT3 controls S1PR1 expression in neurons via a positive feedback mechanism. Interestingly, several models of obesity and cancer anorexia display an imbalance of hypothalamic S1P/S1PR1/STAT3 axis, whereas pharmacological intervention ameliorates these phenotypes. Taken together, our data demonstrate that the neuronal S1P/S1PR1/STAT3 signalling axis plays a critical role in the control of energy homeostasis in rats. PMID:25255053

  16. Production of cellulases and xylanases under catabolic repression conditions from mutant PR-22 of Cellulomonas flavigena.

    PubMed

    Rojas-Rejón, Oscar A; Poggi-Varaldo, Héctor M; Ramos-Valdivia, Ana C; Martínez-Jiménez, Alfredo; Cristiani-Urbina, Eliseo; de la Torre Martínez, Mayra; Ponce-Noyola, Teresa

    2011-01-01

    Derepressed mutant PR-22 was obtained by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) mutagenic treatment of Cellulomonas flavigena PN-120. This mutant improved its xylanolytic activity from 26.9 to 40 U mg(-1) and cellulolytic activity from 1.9 to 4 U mg(-1); this represented rates almost 2 and 1.5 times higher, respectively, compared to its parent strain growing in sugarcane bagasse. Either glucose or cellobiose was added to cultures of C. flavigena PN-120 and mutant PR-22 induced with sugarcane bagasse in batch culture. The inhibitory effect of glucose on xylanase activity was more noticeable for parent strain PN-120 than for mutant PR-22. When 20 mM glucose was added, the xylanolytic activity decreased 41% compared to the culture grown without glucose in mutant PR-22, whereas in the PN-120 strain the xylanolytic activity decreased by 49% at the same conditions compared to its own control. Addition of 10 and 15 mM of glucose did not adversely affect CMCase activity in PR-22, but glucose at 20 mM inhibited the enzymatic activity by 28%. The CMCase activity of the PN-120 strain was more sensitive to glucose than PR-22, with a reduction of CMCase activity in the range of 20-32%. Cellobiose had a more significant effect on xylanase and CMCase activities than glucose did in the mutant PR-22 and parent strain. Nevertheless, the activities under both conditions were always higher in the mutant PR-22 than in the PN-120 strain. Enzymatic saccharification experiments showed that it is possible to accumulate up to 10 g l(-1) of total soluble sugars from pretreated sugarcane bagasse with the concentrated enzymatic crude extract from mutant PR-22.

  17. Meteorologically Driven Simulations of Dengue Epidemics in San Juan, PR

    PubMed Central

    Morin, Cory W.; Monaghan, Andrew J.; Hayden, Mary H.; Barrera, Roberto; Ernst, Kacey

    2015-01-01

    Meteorological factors influence dengue virus ecology by modulating vector mosquito population dynamics, viral replication, and transmission. Dynamic modeling techniques can be used to examine how interactions among meteorological variables, vectors and the dengue virus influence transmission. We developed a dengue fever simulation model by coupling a dynamic simulation model for Aedes aegypti, the primary mosquito vector for dengue, with a basic epidemiological Susceptible-Exposed-Infectious-Recovered (SEIR) model. Employing a Monte Carlo approach, we simulated dengue transmission during the period of 2010–2013 in San Juan, PR, where dengue fever is endemic. The results of 9600 simulations using varied model parameters were evaluated by statistical comparison (r2) with surveillance data of dengue cases reported to the Centers for Disease Control and Prevention. To identify the most influential parameters associated with dengue virus transmission for each period the top 1% of best-fit model simulations were retained and compared. Using the top simulations, dengue cases were simulated well for 2010 (r2 = 0.90, p = 0.03), 2011 (r2 = 0.83, p = 0.05), and 2012 (r2 = 0.94, p = 0.01); however, simulations were weaker for 2013 (r2 = 0.25, p = 0.25) and the entire four-year period (r2 = 0.44, p = 0.002). Analysis of parameter values from retained simulations revealed that rain dependent container habitats were more prevalent in best-fitting simulations during the wetter 2010 and 2011 years, while human managed (i.e. manually filled) container habitats were more prevalent in best-fitting simulations during the drier 2012 and 2013 years. The simulations further indicate that rainfall strongly modulates the timing of dengue (e.g., epidemics occurred earlier during rainy years) while temperature modulates the annual number of dengue fever cases. Our results suggest that meteorological factors have a time-variable influence on dengue transmission relative to other important

  18. Meteorologically Driven Simulations of Dengue Epidemics in San Juan, PR.

    PubMed

    Morin, Cory W; Monaghan, Andrew J; Hayden, Mary H; Barrera, Roberto; Ernst, Kacey

    2015-08-01

    Meteorological factors influence dengue virus ecology by modulating vector mosquito population dynamics, viral replication, and transmission. Dynamic modeling techniques can be used to examine how interactions among meteorological variables, vectors and the dengue virus influence transmission. We developed a dengue fever simulation model by coupling a dynamic simulation model for Aedes aegypti, the primary mosquito vector for dengue, with a basic epidemiological Susceptible-Exposed-Infectious-Recovered (SEIR) model. Employing a Monte Carlo approach, we simulated dengue transmission during the period of 2010-2013 in San Juan, PR, where dengue fever is endemic. The results of 9600 simulations using varied model parameters were evaluated by statistical comparison (r2) with surveillance data of dengue cases reported to the Centers for Disease Control and Prevention. To identify the most influential parameters associated with dengue virus transmission for each period the top 1% of best-fit model simulations were retained and compared. Using the top simulations, dengue cases were simulated well for 2010 (r2 = 0.90, p = 0.03), 2011 (r2 = 0.83, p = 0.05), and 2012 (r2 = 0.94, p = 0.01); however, simulations were weaker for 2013 (r2 = 0.25, p = 0.25) and the entire four-year period (r2 = 0.44, p = 0.002). Analysis of parameter values from retained simulations revealed that rain dependent container habitats were more prevalent in best-fitting simulations during the wetter 2010 and 2011 years, while human managed (i.e. manually filled) container habitats were more prevalent in best-fitting simulations during the drier 2012 and 2013 years. The simulations further indicate that rainfall strongly modulates the timing of dengue (e.g., epidemics occurred earlier during rainy years) while temperature modulates the annual number of dengue fever cases. Our results suggest that meteorological factors have a time-variable influence on dengue transmission relative to other important

  19. Meteorologically Driven Simulations of Dengue Epidemics in San Juan, PR.

    PubMed

    Morin, Cory W; Monaghan, Andrew J; Hayden, Mary H; Barrera, Roberto; Ernst, Kacey

    2015-08-01

    Meteorological factors influence dengue virus ecology by modulating vector mosquito population dynamics, viral replication, and transmission. Dynamic modeling techniques can be used to examine how interactions among meteorological variables, vectors and the dengue virus influence transmission. We developed a dengue fever simulation model by coupling a dynamic simulation model for Aedes aegypti, the primary mosquito vector for dengue, with a basic epidemiological Susceptible-Exposed-Infectious-Recovered (SEIR) model. Employing a Monte Carlo approach, we simulated dengue transmission during the period of 2010-2013 in San Juan, PR, where dengue fever is endemic. The results of 9600 simulations using varied model parameters were evaluated by statistical comparison (r2) with surveillance data of dengue cases reported to the Centers for Disease Control and Prevention. To identify the most influential parameters associated with dengue virus transmission for each period the top 1% of best-fit model simulations were retained and compared. Using the top simulations, dengue cases were simulated well for 2010 (r2 = 0.90, p = 0.03), 2011 (r2 = 0.83, p = 0.05), and 2012 (r2 = 0.94, p = 0.01); however, simulations were weaker for 2013 (r2 = 0.25, p = 0.25) and the entire four-year period (r2 = 0.44, p = 0.002). Analysis of parameter values from retained simulations revealed that rain dependent container habitats were more prevalent in best-fitting simulations during the wetter 2010 and 2011 years, while human managed (i.e. manually filled) container habitats were more prevalent in best-fitting simulations during the drier 2012 and 2013 years. The simulations further indicate that rainfall strongly modulates the timing of dengue (e.g., epidemics occurred earlier during rainy years) while temperature modulates the annual number of dengue fever cases. Our results suggest that meteorological factors have a time-variable influence on dengue transmission relative to other important

  20. Using synthetic small molecule reagents and antibodies to distinguish among PrP conformers: new uses for old antibodies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The chemical environment of the amino acids present in PrP is conformation (PrP(Sc) or PrP(c)) dependent. This means that the same amino acid can react differently with the same chemical reagent, depending upon the conformation of that protein. Furthermore, if the site of chemical reaction is the ep...

  1. A comparison of the structure of the PK-sensitive and PK-resistant forms of PrPSc(Abstract)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background/Introduction. One of the distinctive phenotypes of the infectious isoform of PrP(PrPSc)is its resistance to proteinase K (PK) digestion. The diagnosis of prion diseases is based on this phenotypic observation. More recently, researchers determined that there is a sizeable fraction of PrPS...

  2. Local Inhomogeneity and Filamentary Superconductivity in Pr-Doped CaFe2As2

    NASA Astrophysics Data System (ADS)

    Gofryk, Krzysztof; Pan, Minghu; Cantoni, Claudia; Saparov, Bayrammurad; Mitchell, Jonathan E.; Sefat, Athena S.

    2014-01-01

    We use multiscale techniques to determine the extent of local inhomogeneity and superconductivity in Ca0.86Pr0.14Fe2As2 single crystal. The inhomogeneity is manifested as a spatial variation of the praseodymium concentration, local density of states, and superconducting order parameter. We show that the high-Tc superconductivity emerges from cloverlike defects associated with Pr dopants. The highest Tc is observed in both the tetragonal and collapsed tetragonal phases, and its filamentary nature is a consequence of nonuniform Pr distribution that develops localized, isolated superconducting regions within the crystals.

  3. Genome sequencing and annotation of multidrug resistant Mycobacterium tuberculosis (MDR-TB) PR10 strain.

    PubMed

    Halim, Mohd Zakihalani A; Jaafar, Mohammad Maaruf; Teh, Lay Kek; Ismail, Mohamad Izwan; Lee, Lian Shien; Ngeow, Yun Fong; Nor, Norazmi Mohd; Zainuddin, Zainul Fadziruddin; Tang, Thean Hock; Najimudin, Mohd Nazalan Mohd; Salleh, Mohd Zaki

    2016-03-01

    Here, we report the draft genome sequence and annotation of a multidrug resistant Mycobacterium tuberculosis strain PR10 (MDR-TB PR10) isolated from a patient diagnosed with tuberculosis. The size of the draft genome MDR-TB PR10 is 4.34 Mbp with 65.6% of G + C content and consists of 4637 predicted genes. The determinants were categorized by RAST into 400 subsystems with 4286 coding sequences and 50 RNAs. The whole genome shotgun project has been deposited at DDBJ/EMBL/GenBank under the accession number CP010968.

  4. Pr Substitution at Y and Ba sites in YBCO (123) System

    NASA Astrophysics Data System (ADS)

    Sharma, P. K.; Kumar, Sudhish; Dolia, S. N.; Singhal, R. K.

    2011-07-01

    We present structural, transport, and iodometric study of YBa2Cu3O7-δ system with Pr3+ substituting both the Y3+ and the Ba2+sites. The rate of the Tc depression in the case when with Pr3+ substitutes the Ba2+ is much higher than the case when Pr3+ is substituted at the Y3+ site. This is explained due to a composite effect of the depletion of itinerant holes due to the progressive depletion of the oxygen content, and the loss of orthorhombicity. Further studies on electronic structure and itinerant holes and their relation with superconductivity are underway.

  5. Toxicity of laser irradiated photoactive fluoride PrF3 nanoparticles toward bacteria

    NASA Astrophysics Data System (ADS)

    Pudovkin, M. S.; Korableva, S. L.; Krasheninnicova, A. O.; Nizamutdinov, A. S.; Semashko, V. V.; Zelenihin, P. V.; Alakshin, E. M.; Nevzorova, T. A.

    2014-11-01

    The article is devoted to exploration of biological effects of crystalline PrF3 nanoparticles toward Salmonella typhimurium TA 98 bacteria under the laser irradiation. Obtained results show bactericidal activity of PrF3 nanoparticles and optimal parameters of laser irradiation (power of laser irradiation, wavelength, diameter of the laser spoil, and exposure time) have been found under which the effects of bactericidal activity become the most significant. Survival of bacterial cells under laser irradiation with wavelength 532 nm in colloidal solution of PrF3 nanoparticles was 39%, 34%, 20% for exposure times 5 minutes, 15 minutes and 30 minutes, correspondingly.

  6. Genome sequencing and annotation of multidrug resistant Mycobacterium tuberculosis (MDR-TB) PR10 strain

    PubMed Central

    Halim, Mohd Zakihalani A.; Jaafar, Mohammad Maaruf; Teh, Lay Kek; Ismail, Mohamad Izwan; Lee, Lian Shien; Ngeow, Yun Fong; Nor, Norazmi Mohd; Zainuddin, Zainul Fadziruddin; Tang, Thean Hock; Najimudin, Mohd Nazalan Mohd; Salleh, Mohd Zaki

    2016-01-01

    Here, we report the draft genome sequence and annotation of a multidrug resistant Mycobacterium tuberculosis strain PR10 (MDR-TB PR10) isolated from a patient diagnosed with tuberculosis. The size of the draft genome MDR-TB PR10 is 4.34 Mbp with 65.6% of G + C content and consists of 4637 predicted genes. The determinants were categorized by RAST into 400 subsystems with 4286 coding sequences and 50 RNAs. The whole genome shotgun project has been deposited at DDBJ/EMBL/GenBank under the accession number CP010968. PMID:26981419

  7. Genome sequencing and annotation of multidrug resistant Mycobacterium tuberculosis (MDR-TB) PR10 strain.

    PubMed

    Halim, Mohd Zakihalani A; Jaafar, Mohammad Maaruf; Teh, Lay Kek; Ismail, Mohamad Izwan; Lee, Lian Shien; Ngeow, Yun Fong; Nor, Norazmi Mohd; Zainuddin, Zainul Fadziruddin; Tang, Thean Hock; Najimudin, Mohd Nazalan Mohd; Salleh, Mohd Zaki

    2016-03-01

    Here, we report the draft genome sequence and annotation of a multidrug resistant Mycobacterium tuberculosis strain PR10 (MDR-TB PR10) isolated from a patient diagnosed with tuberculosis. The size of the draft genome MDR-TB PR10 is 4.34 Mbp with 65.6% of G + C content and consists of 4637 predicted genes. The determinants were categorized by RAST into 400 subsystems with 4286 coding sequences and 50 RNAs. The whole genome shotgun project has been deposited at DDBJ/EMBL/GenBank under the accession number CP010968. PMID:26981419

  8. Local inhomogeneity and filamentary superconductivity in Pr-doped CaFe2As2.

    PubMed

    Gofryk, Krzysztof; Pan, Minghu; Cantoni, Claudia; Saparov, Bayrammurad; Mitchell, Jonathan E; Sefat, Athena S

    2014-01-31

    We use multiscale techniques to determine the extent of local inhomogeneity and superconductivity in Ca0.86Pr0.14Fe2As2 single crystal. The inhomogeneity is manifested as a spatial variation of the praseodymium concentration, local density of states, and superconducting order parameter. We show that the high-Tc superconductivity emerges from cloverlike defects associated with Pr dopants. The highest Tc is observed in both the tetragonal and collapsed tetragonal phases, and its filamentary nature is a consequence of nonuniform Pr distribution that develops localized, isolated superconducting regions within the crystals. PMID:24580484

  9. Structure refinements of members in the brownmillerite solid solution series Ca{sub 2}Al{sub x}(Fe{sub 0.5}Mn{sub 0.5}){sub 2-x}O{sub 5+{delta}} with 1/2{<=}x{<=}4/3

    SciTech Connect

    Stoeber, Stefan; Schorr, Susan; Poellmann, Herbert

    2013-01-15

    Four different brownmillerite solid solutions Ca{sub 2}Al{sub x}(Fe{sub 0.5}Mn{sub 0.5}){sub 2-x}O{sub 5+{delta}} with 1/2{<=}x{<=}4/3 were synthesized by a solid oxide ceramic method. The phases crystallize either in a primitive centered orthorhombic cell with space group Pnma or in a body centered cell with space group I2mb dependent on the aluminum concentration present in the solid solution. Mn{sup 3+} ions occupy exclusively site 4a coordinated by six oxygen anions. Increasing Mn{sup 3+} concentrations cause a remarkable distortion of the octahedron and indirectly of the tetrahedron, resulting in twisted and tilted octahedral layers as well as buckled tetrahedral chains. The influences are discussed on the site 4a of trivalent manganese due to its Jahn-Teller activity, with regard to the occupation of octahedron and tetrahedron with different sized iron and aluminum ions. - Graphical Abstract: The coupled substitution Fe{sup 3+}>Mn{sup 3+}+Fe{sup 3+} <=>2 Al{sup 3+} in brownmillerite phases (Ca{sub 2}(Fe{sub 0.5}Mn{sub 0.5}){sub 2-x}Al{sub x}O{sub 5+{delta}}) changes predominantly their structural properties, which is essential for the hydration performance of the calcium aluminate cement, where brownmillerites occur as clinker phases. Highlights: Black-Right-Pointing-Pointer We present structural data of four Ca-Al-Fe-Mn-brownmillerites. Black-Right-Pointing-Pointer Mn{sup 3+}-ions occupy exclusively the octahedrally coordinated site 0,0,0. Black-Right-Pointing-Pointer Bonds and angles of the octahedrally coordinated site are distorted strongly. Black-Right-Pointing-Pointer Mn{sup 3+}-ions influence indirectly the shape of the tetrahedron. Black-Right-Pointing-Pointer Mn{sup 3+}-ions stabilize Pnma instead of I2mb in Ca-Al-Fe-Mn-brownmillerites.

  10. Characteristics of the energy bands and the spectroscopic parameters of Pr3+ ions in PrCl3 mixed methanol, iso-propanol and butanol solutions.

    PubMed

    Jana, Samar; Mitra, Subrata

    2011-12-01

    An investigation on the absorption spectra of the praseodymium chloride (PrCl(3)) in methanol, iso-propanol and butanol is carried out between 190 nm and 1100 nm. We have observed and assigned six energy bands of the 4f(2) electronic configuration of the Pr(3+) ion in the visible to near-infra-red and one due to 4f5d configuration in the ultraviolet region. The 4f5d band has been detected properly for low concentration of PrCl(3). We have also constructed a free-ion Hamiltonian and calculated the energy levels of the 4f(2) configuration theoretically. Hence, the best fit free-ion parameters are deduced.

  11. L’administration postnatale de corticoïdes pour traiter ou prévenir les affections pulmonaires chroniques chez les prématurés

    PubMed Central

    2002-01-01

    Le présent énoncé est conçu à l’intention des professionnels de la santé qui soignent des nouveau-nés et de jeunes nourrissons. Il vise à examiner les effets à court et à long terme de l’administration postnatale de corticoïdes systémiques et par inhalation pour prévenir ou traiter une affection pulmonaire chronique évolutive ou établie et à faire des recommandations quant à l’usage de corticoïdes chez les nourrissons à très faible poids de naissance. Le recours systématique à la dexaméthasone systémique pour prévenir ou traiter une affection pulmonaire chronique n’est pas recommandé chez les nourrissons à très faible poids de naissance.

  12. Catalyseurs cuivre-zinc. X. Comparaison de quelques méthodes de préparation : coprécipitation, précipitations successives ou précurseur bimétallique

    NASA Astrophysics Data System (ADS)

    Brahmi, R.; Kappenstein, C.; Cernák, J.; Duprez, D.; Sadel, A.

    1999-03-01

    The comparison of different preparation procedures of Cu-ZnO catalysts has disclosed the formation of an unidentified copper-zinc phase in the case of precipitation methods. The size of the copper crystallites obtained after reduction is clearly related to the amount to this phase. Moreover, the catalytic activity in methanol synthesis from CO + CO2 + H2 mixture depends on the intermediate formation of this phase. The bimetallic precursor leads to catalyst that displays a lower activity correlated to sintering of copper during the reduction step. La comparaison de différents modes de préparation des catalyseurs Cu/ZnO, montre qu'il y a formation d'une phase non identifiée dans le cas de la précipitation. La taille des cristallites obtenues après réduction est clairement liée à la proportion de cette phase. De plus, l'activité catalytique en synthèse du méthanol à partir du mélange CO + CO2 + H2 dépend aussi de la formation intermédiaire de cette phase. Le précurseur bimétallique conduit à un catalyseur présentant une faible activité qui est liée au frittage de la phase active après l'étape de réduction.

  13. Patterns and Correlates of PrEP Drug Detection among MSM and Transgender Women in the Global iPrEx Study

    PubMed Central

    Liu, Albert; Glidden, David V.; Anderson, Peter L.; Amico, K.R.; McMahan, Vanessa; Mehrotra, Megha; Lama, Javier R.; MacRae, John; Hinojosa, Juan Carlos; Montoya, Orlando; Veloso, Valdilea G.; Schechter, Mauro; Kallas, Esper G.; Chariyalerstak, Suwat; Bekker, Linda-Gail; Mayer, Kenneth; Buchbinder, Susan; Grant, Robert

    2014-01-01

    Background Adherence to pre-exposure prophylaxis (PrEP) is critical for efficacy. Antiretroviral concentrations are an objective measure of PrEP use and correlate with efficacy. Understanding patterns and correlates of drug detection can identify populations at risk for non-adherence and inform design of PrEP adherence interventions. Methods Blood antiretroviral concentrations were assessed among active-arm participants in iPrEx, a randomized, placebo-controlled trial of emtricitabine/tenofovir in men who have sex with men (MSM) and transgender women in 6 countries. We evaluated rates and correlates of drug detection among a random sample of 470 participants at week 8 and a longitudinal cohort of 303 participants through 72 weeks of follow-up. Results Overall, 55% (95% CI 49–60%) of participants tested at week 8 had drug detected. Drug detection was associated with older age and varied by study site. In longitudinal analysis, 31% never had drug detected, 30% always had drug detected, and 39% had an inconsistent pattern. Overall detection rates declined over time. Drug detection at some or all visits was associated with older age; indices of sexual risk, including condomless receptive anal sex; and responding "don't know" to a question about belief of PrEP efficacy (0–10 scale). Conclusions Distinct patterns of study-product use were identified, with a significant proportion demonstrating no drug detection at any visit. Research literacy may explain greater drug detection among populations having greater research experience, such as older MSM in the US. Greater drug detection among those reporting highest-risk sexual practices is expected to increase the impact and cost-effectiveness of PrEP. PMID:25230290

  14. Weak decays of H-like {sup 140}Pr{sup 58+} and He-like {sup 140}Pr{sup 57+} ions

    SciTech Connect

    Ivanov, A. N.; Faber, M.; Reda, R.; Kienle, P.

    2008-08-15

    The nuclear K-shell electron-capture (EC) and positron ({beta}{sup +}) decay constants, {lambda}{sub EC} and {lambda}{sub {beta}{sup +}} of H-like {sup 140}Pr{sup 58+} and He-like {sup 140}Pr{sup 57+} ions, measured recently in the experimental storage ring (ESR) at GSI, were calculated using standard weak interaction theory. The calculated ratios R={lambda}{sub EC}/{lambda}{sub {beta}{sup +}} of the decay constants agree with the experimental values within an accuracy better than 3%.

  15. Optical temperature sensing based on the luminescence from YAG:Pr transparent ceramics

    NASA Astrophysics Data System (ADS)

    Hu, Song; Lu, Chunhua; Liu, Xiaoxia; Xu, Zhongzi

    2016-10-01

    The YAG:Pr transparent ceramic was fabricated using a conventional solid-state reactive method to explore its possible application in optical thermometry. Photoluminescence and temperature-dependent luminescence were elaborately investigated under 452 nm excitation. The ceramic showed two intrinsic emission bands at 488 and 594 nm, which were attributed to characteristic Pr3+: 3P0 → 3H4 and 3P1 → 3H6 transitions, respectively. Down-conversion emissions from the two thermally coupled excited states of Pr3+ were recorded in the temperature range of 293-593 K. The Boltzmann distribution theory was adopted to interpret the temperature-dependent luminescence of Pr3+. The temperature sensitivity exhibited an increasing trend with the increase of temperature, typically, 0.0025 K-1 at 593 K. The results indicated that the present ceramic was a promising candidate for optical temperature sensor.

  16. Colossal dielectric constant and relaxation behaviors in Pr:SrTiO{sub 3} ceramics

    SciTech Connect

    Liu Cheng; Liu Peng; Zhou Jianping; Su Lina; Cao Lei; He Ying; Zhang Huaiwu

    2010-05-15

    Sr{sub 1-x}Pr{sub x}TiO{sub 3} ceramics (0.00{<=}x{<=}0.03) were prepared by a traditional solid-state reaction method. Two relaxation processes (marked as A and B) of the Sr{sub 0.09}Pr{sub 0.01}TiO{sub 3} ceramics were investigated by analyzing the E{sub a} values obtained from the Arrhenius law. Colossal dielectric constant (CDC) was first obtained in Sr{sub 0.09}Pr{sub 0.01}TiO{sub 3} ceramics, whose permittivity was up to 3000 (1 kHz, room temperature), greater than that of pure SrTiO{sub 3} ceramics and samples with more Pr addition (x=0.02 and 0.03). This CDC behavior was related to the internal barrier layer capacitance mechanism.

  17. Neutron-diffraction study of the magnetic structure of PrCoAl 4

    NASA Astrophysics Data System (ADS)

    Schobinger-Papamantellos, P.; Wilkinson, C.; Tung, L. D.; Buschow, K. H. J.; McIntyre, G. J.

    2004-12-01

    The magnetic structure of PrCoAl4 has been studied by neutron diffraction from a single crystal. The Pr moments order at a temperature near to 20 K with a sine-wave longitudinal amplitude-modulated structure. The length of the wave vector q = (0 0qz) is almost temperature independent with qz = 0.4087 (5) , and only the first harmonic was observed down to 2 K. The amplitude of the wave, 2.05(3) μB/Pr atom at 2 K, is reduced compared to the Pr3+ free-ion moment value g JμB = 3.2μB , due to strong crystal-field effects. One difference between the present and previously reported neutron powder-diffraction results concerns the wave vector length. The reason for this may lie in the different magnetic microstructure (stacking faults) of the material depending on the thermochemical history of each sample.

  18. A PR-1-like protein of Fusarium oxysporum functions in virulence on mammalian hosts.

    PubMed

    Prados-Rosales, Rafael C; Roldán-Rodríguez, Raquel; Serena, Carolina; López-Berges, Manuel S; Guarro, Josep; Martínez-del-Pozo, Álvaro; Di Pietro, Antonio

    2012-06-22

    The pathogenesis-related PR-1-like protein family comprises secreted proteins from the animal, plant, and fungal kingdoms whose biological function remains poorly understood. Here we have characterized a PR-1-like protein, Fpr1, from Fusarium oxysporum, an ubiquitous fungal pathogen that causes vascular wilt disease on a wide range of plant species and can produce life-threatening infections in immunocompromised humans. Fpr1 is secreted and proteolytically processed by the fungus. The fpr1 gene is required for virulence in a disseminated immunodepressed mouse model, and its function depends on the integrity of the proposed active site of PR-1-like proteins. Fpr1 belongs to a gene family that has expanded in plant pathogenic Sordariomycetes. These results suggest that secreted PR-1-like proteins play important roles in fungal pathogenicity. PMID:22553200

  19. Elastic behavior around metal-insulator transition in PrRu 4P 12

    NASA Astrophysics Data System (ADS)

    Nakanishi, Y.; Kumagai, T.; Oikawa, M.; Saha, S. R.; Sugawara, H.; Sato, H.; Yoshizawa, M.

    2006-03-01

    Elastic properties of PrRu 4P 12 have been investigated by means of the ultrasonic measurement. A clear bend was observed in elastic constants C11, (C11-C12)/2 and C44 at metal-insulator transition temperature TMI of 62.3 K. Furthermore, C11, and ( C11-C12)/2 exhibits a pronounced elastic softening towards low temperature in the temperature range down to 1.5 K. This fact suggests strongly that PrΓ3 non-Kramers doublet ground state is realized in PrRu 4P 12 under the crystalline electric field (CEF) potential. This also suggests that an orbital degree of freedom still remains below TMI and a quadrupolar ordering has nothing to do with the metal-insulator transition. The elastic property and 4f ground state of Pr ions in this system will be discussed from the view point of CEF effect.

  20. Présentation générale

    NASA Astrophysics Data System (ADS)

    Volino, F.

    Le travail faisant l'objet de cette série d'articles de titre général "Théorie visco-élastique non-extensive", numérotée de (I) à (VI), a été initialement motivé par l'analyse de mesures de Résonance Magnétique Nucléaire (RMN) sur des polymères nématogènes dans les phases nématique et isotrope [1,2,3,4,5,6,7,8]. Sans entrer dans le détail de ces mesures, rappelons que les mouvements des molécules rétrécissent les raies RMN, mais que, avec des molécules aussi grosses que ces polymères, on est en dehors du régime de rétrécissement extrême, donc dans un régime ou la forme de raie dépend du détail des mouvements [9]. La théorie des modes élastiques des nématiques fournissait le cadre conceptuel naturel pour décrire de tels mouvements. L'application de cette théorie, qui, dans une version simplifiée, mais suffisante en pratique, ne fait intervenir que deux paramètres ajustables, le paramètre d'ordre nématique et une viscosité moyenne, a effectivement permis de reproduire dans le détail des formes de raie RMN de polymères en phase nématique, avec des valeurs des deux paramètres en accord avec celles qui avaient pu être estimées par des mesures directes. La théorie des modes élastiques était donc testée avec succès par l'analyse de formes de raies RMN. L'analyse en phase nématique apparaissait bien auto-cohérente [5]. Une incohérence logique est cependant apparue dans les études qui ont suivi. Les ajustements précédents avaient été faits pour des spectres obtenus au milieu de la phase nématique, ou l'ordre orientationnel est relativement élevé. Cependant, l'ordre diminue en chauffant, et on a trouvé qu'il est toujours possible de simuler les formes de raies avec le même modèle, en changeant les valeurs du paramètre d'ordre et de la viscosité. - la transition nématique-isotrope, l'expérience montre que l'allure générale des spectres RMN du polymère change peu, et le calcul montre qu'ils peuvent être

  1. How to manage a hospital PR crisis. Interviewed by Gini Dietrich.

    PubMed

    Showalter, J Stuart

    2013-07-01

    Action steps hospitals and health systems should take to prepare for a public relations (PR) crisis include the following: Develop a plan for dealing with PR crises that establishes a central incident command center and sets forth clear lines of authority and responsibility. Provide the name, phone number, email address, and other contact information for a knowledgeable person who can respond to media inquiries. Act fast--within a couple of hours--to explain the facts.

  2. Transgenic Rabbits Expressing Ovine PrP Are Susceptible to Scrapie

    PubMed Central

    Sarradin, Pierre; Viglietta, Céline; Limouzin, Claude; Andréoletti, Olivier; Daniel-Carlier, Nathalie; Barc, Céline; Leroux-Coyau, Mathieu; Berthon, Patricia; Chapuis, Jérôme; Rossignol, Christelle; Gatti, Jean-Luc; Belghazi, Maya; Labas, Valérie; Vilotte, Jean-Luc; Béringue, Vincent; Lantier, Frédéric; Laude, Hubert; Houdebine, Louis-Marie

    2015-01-01

    Transmissible spongiform encephalopathies (TSEs) are a group of neurodegenerative diseases affecting a wide range of mammalian species. They are caused by prions, a proteinaceous pathogen essentially composed of PrPSc, an abnormal isoform of the host encoded cellular prion protein PrPC. Constrained steric interactions between PrPSc and PrPC are thought to provide prions with species specificity, and to control cross-species transmission into other host populations, including humans. Transgenetic expression of foreign PrP genes has been successfully and widely used to overcome the recognized resistance of mouse to foreign TSE sources. Rabbit is one of the species that exhibit a pronounced resistance to TSEs. Most attempts to infect experimentally rabbit have failed, except after inoculation with cell-free generated rabbit prions. To gain insights on the molecular determinants of the relative resistance of rabbits to prions, we generated transgenic rabbits expressing the susceptible V136R154Q171 allele of the ovine PRNP gene on a rabbit wild type PRNP New Zealand background and assessed their experimental susceptibility to scrapie prions. All transgenic animals developed a typical TSE 6–8 months after intracerebral inoculation, whereas wild type rabbits remained healthy more than 700 days after inoculation. Despite the endogenous presence of rabbit PrPC, only ovine PrPSc was detectable in the brains of diseased animals. Collectively these data indicate that the low susceptibility of rabbits to prion infection is not enciphered within their non-PrP genetic background. PMID:26248157

  3. Evaluation of the Allergenicity Potential of TcPR-10 Protein from Theobroma cacao

    PubMed Central

    Cardoso, Thyago Hermylly Santana; Pirovani, Carlos Priminho; Micheli, Fabienne; Noronha, Fátima Soares Motta; Alves, Andréa Catão; Faria, Ana Maria Caetano; da Silva Gesteira, Abelmon

    2012-01-01

    Background The pathogenesis related protein PR10 (TcPR-10), obtained from the Theobroma cacao-Moniliophthora perniciosa interaction library, presents antifungal activity against M. perniciosa and acts in vitro as a ribonuclease. However, despite its biotechnological potential, the TcPR-10 has the P-loop motif similar to those of some allergenic proteins such as Bet v 1 (Betula verrucosa) and Pru av 1 (Prunus avium). The insertion of mutations in this motif can produce proteins with reduced allergenic power. The objective of the present work was to evaluate the allergenic potential of the wild type and mutant recombinant TcPR-10 using bioinformatics tools and immunological assays. Methodology/Principal Findings Mutant substitutions (T10P, I30V, H45S) were inserted in the TcPR-10 gene by site-directed mutagenesis, cloned into pET28a and expressed in Escherichia coli BL21(DE3) cells. Changes in molecular surface caused by the mutant substitutions was evaluated by comparative protein modeling using the three-dimensional structure of the major cherry allergen, Pru av 1 as a template. The immunological assays were carried out in 8–12 week old female BALB/c mice. The mice were sensitized with the proteins (wild type and mutants) via subcutaneous and challenged intranasal for induction of allergic airway inflammation. Conclusions/Significance We showed that the wild TcPR-10 protein has allergenic potential, whereas the insertion of mutations produced proteins with reduced capacity of IgE production and cellular infiltration in the lungs. On the other hand, in vitro assays show that the TcPR-10 mutants still present antifungal and ribonuclease activity against M. perniciosa RNA. In conclusion, the mutant proteins present less allergenic potential than the wild TcPR-10, without the loss of interesting biotechnological properties. PMID:22768037

  4. Transcription variants of the prostate-specific PrLZ gene and their interaction with 14-3-3 proteins

    SciTech Connect

    Wang, Ruoxiang; He, Hui; Sun, Xiaojuan; Xu, Jianchun; Marshall, Fray F.; Zhau, Haiyen; Chung, Leland W.K.; Fu, Haian; He, Dalin

    2009-11-20

    We have reported isolation and characterization of the prostate-specific and androgen-regulated PrLZ gene abnormally expressed in prostate cancer. PrLZ is a potential biomarker for prostate cancer and a candidate oncogene promoting cell proliferation and survival in prostate cancer cells. A full delineation of the PrLZ gene and its gene products may provide clues to the mechanisms regulating its expression and function. In this report, we identified three additional exons in the PrLZ gene and recognized five transcript variants from alternative splicing that could be detected by RT-PCR and Western blotting. Structural comparison demonstrated that the PrLZ proteins are highly conserved among species. PrLZ contains multiple potential sites for interaction with other proteins. We used mammalian two-hybrid assays to demonstrate that PrLZ isoforms interact with 14-3-3 proteins, and multiple sites in the PrLZ may be involved in the interaction. Alternative splicing may contribute to abnormally enhanced PrLZ levels in prostate cancer, and interaction with 14-3-3 proteins may be a mechanism by which PrLZ promotes cell proliferation and survival during prostate cancer development and progression. This information is a valuable addition to the investigation of the oncogenic properties of the PrLZ gene.

  5. Generation of antibodies against prion protein by scrapie-infected cell immunization of PrP(0/0) mice.

    PubMed

    Nakamura, Naoto; Miyamoto, Kazuyoshi; Shimokawa, Mariko; Nishida, Noriuki; Mohri, Shirou; Kitamoto, Tetsuyuki; Horiuchi, Hiroyuki; Furusawa, Shuichi; Matsuda, Haruo

    2003-08-01

    Four monoclonal antibodies (MAbs) specific for prion protein (PrP) were generated by using PrP-knockout mice immunized with a scrapie-infected mouse neuroblastoma cell line (N2a/22L). The MAbs reacted with both the cellular form (PrP(C)) and the protease K-treated form (PrP(Sc)) on Western blotting. Of the four MAbs, three recognized mouse and hamster PrP, while the remaining MAb recognized mouse, sheep, and bovine PrPs. In addition, these MAbs were shown to react only with the unglycosylated and monoglycoslated forms of PrP(Sc) in N2a/22L, but reacted with all glycosylated forms of PrP(C) and PrP(Sc) from mouse brain. This study was the first to report the development of anti-PrP MAbs using scrapie-infected cells as an immunogen and provides one approach for the generation of PrP-specific MAbs.

  6. Ultrasonic attenuation anomalies of n-type superconductor Pr2-xCexCuO4

    NASA Astrophysics Data System (ADS)

    Chong, Tet Vui; Abd-Shukor, R.

    2016-08-01

    Pr2-xCexCuO4 (x = 0 and 0.15) samples were prepared via solid state reaction. Pr2CuO4 sample is insulating while Pr1.85Ce0.15CuO4 sample exhibited an onset critical temperature, Tc of 21 K. The temperature dependences of ultrasonic attenuation in these polycrystalline n-type superconductor Pr2-xCexCuO4 (x = 0 and 0.15) samples have been measured between 80 K and 300 K using longitudinal and shear waves by pulse-echo-overlap method with frequencies between 5 MHz and 10 MHz. For the longitudinal mode, a pronounced attenuation peak around 200 K was observed in Pr2CuO4, but it is not observed in the superconducting material Pr1.85Ce0.15CuO4. For the shear mode, no pronounced attenuation peaks were observed in the samples. It is suggested that the attenuation peak in the x = 0 sample at 200 K is due to the weak structural distortion induced by the magnetic transition.

  7. Detergents modify proteinase K resistance of PrP Sc in different transmissible spongiform encephalopathies (TSEs).

    PubMed

    Breyer, Johanna; Wemheuer, Wiebke M; Wrede, Arne; Graham, Catherine; Benestad, Sylvie L; Brenig, Bertram; Richt, Jürgen A; Schulz-Schaeffer, Walter J

    2012-05-25

    Prion diseases are diagnosed by the detection of their proteinase K-resistant prion protein fragment (PrP(Sc)). Various biochemical protocols use different detergents for the tissue preparation. We found that the resistance of PrP(Sc) against proteinase K may vary strongly with the detergent used. In our study, we investigated the influence of the most commonly used detergents on eight different TSE agents derived from different species and distinct prion disease forms. For a high throughput we used a membrane adsorption assay to detect small amounts of prion aggregates, as well as Western blotting. Tissue lysates were prepared using DOC, SLS, SDS or Triton X-100 in different concentrations and these were digested with various amounts of proteinase K. Detergents are able to enhance or diminish the detectability of PrP(Sc) after proteinase K digestion. Depending on the kind of detergent, its concentration - but also on the host species that developed the TSE and the disease form or prion type - the detectability of PrP(Sc) can be very different. The results obtained here may be helpful during the development or improvement of a PrP(Sc) detection method and they point towards a detergent effect that can be additionally used for decontamination purposes. A plausible explanation for the detergent effects described in this article could be an interaction with the lipids associated with PrP(Sc) that may stabilize the aggregates.

  8. CO and Soot Oxidation over Ce-Zr-Pr Oxide Catalysts

    NASA Astrophysics Data System (ADS)

    Andana, Tahrizi; Piumetti, Marco; Bensaid, Samir; Russo, Nunzio; Fino, Debora; Pirone, Raffaele

    2016-06-01

    A set of ceria, ceria-zirconia (Ce 80 at.%, Zr 20 at.%), ceria-praseodymia (Ce 80 at.%, Pr 20 at.%) and ceria-zirconia-praseodymia (Ce 80 at.%, Zr 10 at.% and Pr 10 at.%) catalysts has been prepared by the solution combustion synthesis (SCS). The effects of Zr and Pr as dopants on ceria have been studied in CO and soot oxidation reactions. All the prepared catalysts have been characterized by complementary techniques, including XRD, FESEM, N2 physisorption at -196 °C, H2-temperature-programmed reduction, and X-ray photoelectron spectroscopy to investigate the relationships between the structure and composition of materials and their catalytic performance. Better results for CO oxidation have been obtained with mixed oxides (performance scale, Ce80Zr10Pr10 > Ce80Zr20 > Ce80Pr20) rather than pure ceria, thus confirming the beneficial role of multicomponent catalysts for this prototypical reaction. Since CO oxidation occurs via a Mars-van Krevelen (MvK)-type mechanism over ceria-based catalysts, it appears that the presence of both Zr and Pr species into the ceria framework improves the oxidation activity, via collective properties, such as electrical conductivity and surface or bulk oxygen anion mobility. On the other hand, this positive effect becomes less prominent in soot oxidation, since the effect of catalyst morphology prevails.

  9. CO and Soot Oxidation over Ce-Zr-Pr Oxide Catalysts.

    PubMed

    Andana, Tahrizi; Piumetti, Marco; Bensaid, Samir; Russo, Nunzio; Fino, Debora; Pirone, Raffaele

    2016-12-01

    A set of ceria, ceria-zirconia (Ce 80 at.%, Zr 20 at.%), ceria-praseodymia (Ce 80 at.%, Pr 20 at.%) and ceria-zirconia-praseodymia (Ce 80 at.%, Zr 10 at.% and Pr 10 at.%) catalysts has been prepared by the solution combustion synthesis (SCS). The effects of Zr and Pr as dopants on ceria have been studied in CO and soot oxidation reactions. All the prepared catalysts have been characterized by complementary techniques, including XRD, FESEM, N2 physisorption at -196 °C, H2-temperature-programmed reduction, and X-ray photoelectron spectroscopy to investigate the relationships between the structure and composition of materials and their catalytic performance. Better results for CO oxidation have been obtained with mixed oxides (performance scale, Ce80Zr10Pr10 > Ce80Zr20 > Ce80Pr20) rather than pure ceria, thus confirming the beneficial role of multicomponent catalysts for this prototypical reaction. Since CO oxidation occurs via a Mars-van Krevelen (MvK)-type mechanism over ceria-based catalysts, it appears that the presence of both Zr and Pr species into the ceria framework improves the oxidation activity, via collective properties, such as electrical conductivity and surface or bulk oxygen anion mobility. On the other hand, this positive effect becomes less prominent in soot oxidation, since the effect of catalyst morphology prevails.

  10. Preexposure Prophylaxis (PrEP) for HIV Prevention: The Primary Care Perspective.

    PubMed

    Conniff, James; Evensen, Ann

    2016-01-01

    Until recently there have been few primary care office-based strategies to reduce the transmission of HIV. In May 2014 the Centers for Disease Control and Prevention published updated practice guidelines recommending the use of preexposure prophylaxis (PrEP) with daily oral dosing of tenofovir/emtricitabine to help prevent HIV infection in high-risk individuals (strength of recommendation, A). Knowledge of PrEP among primary care providers is low, however, and this intervention is likely reaching only a small fraction of eligible patients. PrEP is recommended for certain injection drug users, nonmonogamous men who have sex with men, heterosexual women who have sex with men who have sex with men or injection drug users, and those in HIV serodiscordant relationships. Providers should obtain baseline laboratory values and provide initial counseling before prescribing PrEP. Regular office visits are necessary to ensure adherence, provide ongoing counseling, and monitor for side effects, including nausea, abdominal pain, headache, and, less commonly, increased creatinine. Guidelines and toolkits have been developed to assist in incorporating PrEP into primary care practice. PrEP is gaining widespread acceptance and has become a crucial tool in the fight to stop the spread of HIV.

  11. Crossing species barrier by PrPSc replication in vitro generates new infectious prions

    PubMed Central

    Castilla, Joaquín; Gonzalez-Romero, Dennisse; Saá, Paula; Morales, Rodrigo; De Castro, Jorge; Soto, Claudio

    2008-01-01

    Summary Prions are unconventional infectious agents composed exclusively by the misfolded prion protein (PrPSc), which transmits the disease by propagating its abnormal conformation to the cellular prion protein (PrPC). A key characteristic of prions is their species barrier, by which prions from one species can only infect a limited number of other species. Here we report the generation of novel infectious prions by inter-species transmission of PrPSc misfolding in vitro. Hamster PrPC misfolded by mixing with mouse PrPSc generated new prions that were infectious to wild type hamsters. Similarly, new mouse prions were generated by crossing the species barrier in the opposite direction. A detailed characterization of the infectious, biochemical and histological properties of the disease produced indicate that the in vitro generated material across the species barrier correspond to new prion strains. Successive rounds of PMCA amplification result in a progressive adaptation of the in vitro produced prions, in a process reminiscent to the strain stabilization process observed upon serial passage in vivo. Our results indicate that PMCA is a valuable tool to investigate cross-species transmission and suggest that species barrier and strain generation are determined by the propagation of PrP misfolding. PMID:18775309

  12. Involvement of PrP(C) in kainate-induced excitotoxicity in several mouse strains.

    PubMed

    Carulla, Patricia; Llorens, Franc; Matamoros-Angles, Andreu; Aguilar-Calvo, Patricia; Espinosa, Juan Carlos; Gavín, Rosalina; Ferrer, Isidre; Legname, Giuseppe; Torres, Juan Maria; del Río, José A

    2015-01-01

    The cellular prion protein (PrP(C)) has been associated with a plethora of cellular functions ranging from cell cycle to neuroprotection. Mice lacking PrP(C) show an increased susceptibility to epileptic seizures; the protein, then, is neuroprotective. However, lack of experimental reproducibility has led to considering the possibility that other factors besides PrP(C) deletion, such as the genetic background of mice or the presence of so-called "Prnp flanking genes", might contribute to the reported susceptibility. Here, we performed a comparative analysis of seizure-susceptibility using characterized Prnp(+/+) and Prnp(0/0) mice of B6129, B6.129, 129/Ola or FVB/N genetic backgrounds. Our study indicates that PrP(C) plays a role in neuroprotection in KA-treated cells and mice. For this function, PrP(C) should contain the aa32-93 region and needs to be linked to the membrane. In addition, some unidentified "Prnp-flanking genes" play a role parallel to PrP(C) in the KA-mediated responses in B6129 and B6.129 Prnp(0/0) mice. PMID:26155834

  13. High pressure luminescence spectra of CaMoO4:Ln3+ (Ln = Pr, Tb).

    PubMed

    Mahlik, S; Behrendt, M; Grinberg, M; Cavalli, E; Bettinelli, M

    2013-03-13

    Photoluminescence spectra and luminescence kinetics of pure CaMoO(4) and CaMoO(4) doped with Ln(3+) (Ln = Pr or Tb) are presented. The spectra were obtained at high hydrostatic pressure up to 240 kbar applied in a diamond anvil cell. At ambient pressure undoped and doped samples exhibit a broad band emission extending between 380 and 700 nm with a maximum at 520 nm attributed to the MoO(4)(2-) luminescence. CaMoO(4) doped with Pr(3+) or Tb(3+) additionally yields narrow emission lines related to f-f transitions. The undoped CaMoO(4) crystal was characterized by a strong MoO(4)(2-) emission up to 240 kbar. In the cases of CaMoO(4):Pr(3+) and CaMoO(4):Tb(3+), high hydrostatic pressure caused quenching of Pr(3+) and Tb(3+) emission, and this effect was accompanied by a strong shortening of the luminescence lifetime. In doped samples, CaMoO(4):Pr(3+) and CaMoO(4):Tb(3+), quenching of the emission band attributed to MoO(4)(2-) was also observed, and at pressure above 130 kbar this luminescence was totally quenched. The effects mentioned above were related to the influence of the praseodymium (terbium) trapped exciton PTE (ITE-impurity trapped exciton) on the efficiency of the Pr(3+) (Tb(3+)) and MoO(4)(2-) emissions.

  14. High spin states in {sup 151,153}Pr, {sup 157}Sm, and {sup 93}Kr

    SciTech Connect

    Hwang, J. K.; Ramayya, A. V.; Hamilton, J. H.; Liu, S. H.; Brewer, N. T.; Luo, Y. X.; Rasmussen, J. O.; Zhu, S. J.; Donangelo, R.

    2010-09-15

    High spin states are observed for the first time in the neutron-rich nuclei {sup 151,153}Pr, {sup 157}Sm, and {sup 93}Kr from the spontaneous fission of {sup 252}Cf. Twenty new transitions in {sup 151}Pr, twelve in {sup 153}Pr, five in {sup 157}Sm, and four in {sup 93}Kr were identified by using x-ray(Pr/Sm)-{gamma}-{gamma} and {gamma}-{gamma}-{gamma} triple coincidences. From the measured total internal conversion coefficients {alpha}{sub T} of four low-energy transitions in {sup 151,153}Pr, we determine that two bands in each nucleus have opposite parity. The interlacing E1 transitions between the bands suggest a form of parity doubling in {sup 151,153}Pr. New bands in {sup 157}Sm and {sup 93}Kr are reported. The half-life of the 354.8 keV state in {sup 93}Kr is measured to be 10(2) ns.

  15. Dengue Patients Exhibit Higher Levels of PrM and E Antibodies Than Their Asymptomatic Counterparts

    PubMed Central

    Yeo, Adeline Syin Lian; Manikam, Rishya; Sathar, Jameela; Kumari Natkunam, Santha

    2015-01-01

    Dengue virus infection is a common tropical disease which often occurs without being detected. These asymptomatic cases provide information in relation to the manifestation of immunological aspects. In this study, we developed an ELISA method to compare neutralizing effects of dengue prM and E antibodies between dengue patients and their asymptomatic household members. Recombinant D2 premembrane (prM) was constructed, cloned, and tested for antigenicity. The recombinant protein was purified and tested with controls by using an indirect ELISA method. Positive dengue serum samples with their asymptomatic pair were then carried out onto the developed ELISA. In addition, commercially available recombinant envelope (E) protein was used to develop an ELISA which was tested with the same set of serum samples in the prM ELISA. Asymptomatic individuals showed preexisting heterotypic neutralizing antibodies. The recombinant prM was antigenically reactive in the developed ELISA. Dengue patients had higher prM and E antibodies compared to their household members. Our study highlights the neutralizing antibodies levels with respect to dengue prM and E between dengue patients and asymptomatic individuals. PMID:25815314

  16. Prion Infections and Anti-PrP Antibodies Trigger Converging Neurotoxic Pathways

    PubMed Central

    Herrmann, Uli S.; Sonati, Tiziana; Falsig, Jeppe; Reimann, Regina R.; Dametto, Paolo; O’Connor, Tracy; Li, Bei; Lau, Agnes; Hornemann, Simone; Sorce, Silvia; Wagner, Uli; Sanoudou, Despina; Aguzzi, Adriano

    2015-01-01

    Prions induce lethal neurodegeneration and consist of PrPSc, an aggregated conformer of the cellular prion protein PrPC. Antibody-derived ligands to the globular domain of PrPC (collectively termed GDL) are also neurotoxic. Here we show that GDL and prion infections activate the same pathways. Firstly, both GDL and prion infection of cerebellar organotypic cultured slices (COCS) induced the production of reactive oxygen species (ROS). Accordingly, ROS scavenging, which counteracts GDL toxicity in vitro and in vivo, prolonged the lifespan of prion-infected mice and protected prion-infected COCS from neurodegeneration. Instead, neither glutamate receptor antagonists nor inhibitors of endoplasmic reticulum calcium channels abolished neurotoxicity in either model. Secondly, antibodies against the flexible tail (FT) of PrPC reduced neurotoxicity in both GDL-exposed and prion-infected COCS, suggesting that the FT executes toxicity in both paradigms. Thirdly, the PERK pathway of the unfolded protein response was activated in both models. Finally, 80% of transcriptionally downregulated genes overlapped between prion-infected and GDL-treated COCS. We conclude that GDL mimic the interaction of PrPSc with PrPC, thereby triggering the downstream events characteristic of prion infection. PMID:25710374

  17. CO and Soot Oxidation over Ce-Zr-Pr Oxide Catalysts.

    PubMed

    Andana, Tahrizi; Piumetti, Marco; Bensaid, Samir; Russo, Nunzio; Fino, Debora; Pirone, Raffaele

    2016-12-01

    A set of ceria, ceria-zirconia (Ce 80 at.%, Zr 20 at.%), ceria-praseodymia (Ce 80 at.%, Pr 20 at.%) and ceria-zirconia-praseodymia (Ce 80 at.%, Zr 10 at.% and Pr 10 at.%) catalysts has been prepared by the solution combustion synthesis (SCS). The effects of Zr and Pr as dopants on ceria have been studied in CO and soot oxidation reactions. All the prepared catalysts have been characterized by complementary techniques, including XRD, FESEM, N2 physisorption at -196 °C, H2-temperature-programmed reduction, and X-ray photoelectron spectroscopy to investigate the relationships between the structure and composition of materials and their catalytic performance. Better results for CO oxidation have been obtained with mixed oxides (performance scale, Ce80Zr10Pr10 > Ce80Zr20 > Ce80Pr20) rather than pure ceria, thus confirming the beneficial role of multicomponent catalysts for this prototypical reaction. Since CO oxidation occurs via a Mars-van Krevelen (MvK)-type mechanism over ceria-based catalysts, it appears that the presence of both Zr and Pr species into the ceria framework improves the oxidation activity, via collective properties, such as electrical conductivity and surface or bulk oxygen anion mobility. On the other hand, this positive effect becomes less prominent in soot oxidation, since the effect of catalyst morphology prevails. PMID:27255898

  18. Dengue patients exhibit higher levels of PrM and E antibodies than their asymptomatic counterparts.

    PubMed

    Yeo, Adeline Syin Lian; Rathakrishnan, Anusyah; Wang, Seok Mui; Ponnampalavanar, Sasheela; Manikam, Rishya; Sathar, Jameela; Kumari Natkunam, Santha; Sekaran, Shamala Devi

    2015-01-01

    Dengue virus infection is a common tropical disease which often occurs without being detected. These asymptomatic cases provide information in relation to the manifestation of immunological aspects. In this study, we developed an ELISA method to compare neutralizing effects of dengue prM and E antibodies between dengue patients and their asymptomatic household members. Recombinant D2 premembrane (prM) was constructed, cloned, and tested for antigenicity. The recombinant protein was purified and tested with controls by using an indirect ELISA method. Positive dengue serum samples with their asymptomatic pair were then carried out onto the developed ELISA. In addition, commercially available recombinant envelope (E) protein was used to develop an ELISA which was tested with the same set of serum samples in the prM ELISA. Asymptomatic individuals showed preexisting heterotypic neutralizing antibodies. The recombinant prM was antigenically reactive in the developed ELISA. Dengue patients had higher prM and E antibodies compared to their household members. Our study highlights the neutralizing antibodies levels with respect to dengue prM and E between dengue patients and asymptomatic individuals. PMID:25815314

  19. Involvement of PrPC in kainate-induced excitotoxicity in several mouse strains

    PubMed Central

    Carulla, Patricia; Llorens, Franc; Matamoros-Angles, Andreu; Aguilar-Calvo, Patricia; Espinosa, Juan Carlos; Gavín, Rosalina; Ferrer, Isidre; Legname, Giuseppe; Torres, Juan Maria; del Río, José A.

    2015-01-01

    The cellular prion protein (PrPC) has been associated with a plethora of cellular functions ranging from cell cycle to neuroprotection. Mice lacking PrPC show an increased susceptibility to epileptic seizures; the protein, then, is neuroprotective. However, lack of experimental reproducibility has led to considering the possibility that other factors besides PrPC deletion, such as the genetic background of mice or the presence of so-called “Prnp flanking genes”, might contribute to the reported susceptibility. Here, we performed a comparative analysis of seizure-susceptibility using characterized Prnp+/+ and Prnp0/0 mice of B6129, B6.129, 129/Ola or FVB/N genetic backgrounds. Our study indicates that PrPC plays a role in neuroprotection in KA-treated cells and mice. For this function, PrPC should contain the aa32–93 region and needs to be linked to the membrane. In addition, some unidentified “Prnp-flanking genes” play a role parallel to PrPC in the KA-mediated responses in B6129 and B6.129 Prnp0/0 mice. PMID:26155834

  20. Luminescence properties of Pr3+ and Sm3+ ions in natural apatites

    NASA Astrophysics Data System (ADS)

    Czaja, M.; Bodył, S.; Lisiecki, R.; Mazurak, Z.

    2010-07-01

    The luminescence spectra of Pr3+ and Sm3+ ions in apatite Ca5[F∣(PO4)3] crystals from Spain and Russia have been compared with those for phosphate glasses doped with Pr3+, Sm3+ and Pr3+, Sm3+ ions. Time-resolved spectra measurements confirm that, in apatites, samarium ions occupy two non-equivalent crystal sites; the same is assumed for praseodymium ions. For the first time in minerals, the Stark splitting energy levels Δ E for 3H6 and 1D2 of Pr3+ ion and 6H7/2 of Sm3+ ion were determined. Some small differences in Δ E values for the Spanish and Russian apatite are discussed. The decay times of the excited levels of Pr3+, Sm3+ and Pr3+, Sm3+ doped in phosphate glass were measured at room temperature and at 77 K. The energy transfer process between samarium and praseodymium ions was observed and the energy transfer rate was calculated.

  1. High pressure luminescence spectra of CaMoO4:Ln3+ (Ln = Pr, Tb)

    NASA Astrophysics Data System (ADS)

    Mahlik, S.; Behrendt, M.; Grinberg, M.; Cavalli, E.; Bettinelli, M.

    2013-03-01

    Photoluminescence spectra and luminescence kinetics of pure CaMoO4 and CaMoO4 doped with Ln3+ (Ln = Pr or Tb) are presented. The spectra were obtained at high hydrostatic pressure up to 240 kbar applied in a diamond anvil cell. At ambient pressure undoped and doped samples exhibit a broad band emission extending between 380 and 700 nm with a maximum at 520 nm attributed to the {{MoO}}_{4}^{2-} luminescence. CaMoO4 doped with Pr3+ or Tb3+ additionally yields narrow emission lines related to f-f transitions. The undoped CaMoO4 crystal was characterized by a strong MoO{}_{4}^{2-} emission up to 240 kbar. In the cases of CaMoO4:Pr3+ and CaMoO4:Tb3+, high hydrostatic pressure caused quenching of Pr3+ and Tb3+ emission, and this effect was accompanied by a strong shortening of the luminescence lifetime. In doped samples, CaMoO4:Pr3+ and CaMoO4:Tb3+, quenching of the emission band attributed to {{MoO}}_{4}^{2-} was also observed, and at pressure above 130 kbar this luminescence was totally quenched. The effects mentioned above were related to the influence of the praseodymium (terbium) trapped exciton PTE (ITE—impurity trapped exciton) on the efficiency of the Pr3+ (Tb3+) and {{MoO}}_{4}^{2-} emissions.

  2. Continuous-wave Pr³⁺:BaY₂F₈ and Pr³⁺:LiYF₄ lasers in the cyan-blue spectral region.

    PubMed

    Metz, P W; Hasse, K; Parisi, D; Hansen, N-O; Kränkel, C; Tonelli, M; Huber, G

    2014-09-01

    We report on the first, to the best of our knowledge, continuous-wave quasi three-level lasers emitting in the cyan-blue spectral range in praseodymium-doped crystalline materials. Applying Pr(3+):BaY2F8 as an active medium, up to 201 mW of output power at 495 nm could be obtained with a slope efficiency of 27% under pumping with an optically pumped semiconductor laser (2ω-OPSL) at 480 nm. In the same pumping scheme using Pr(3+):LiYF4, output powers up to 70 mW were realized at 491 and 500 nm, respectively. With Pr(3+):BaY2F8, diode-pumped laser operation with up to 11% slope efficiency and 44 mW output power was also achieved. In the latter case, detailed investigations on the temperature dependency of the laser output were conducted. Moreover, comparative experiments were carried out for the first time, to the best of our knowledge, with green-emitting Pr(3+):BaY2F8 lasers at 524 and 553 nm both under diode and 2ω-OPSL excitation. PMID:25166098

  3. Anisotropic magnetic properties and giant magnetocaloric effect of single-crystal PrSi

    NASA Astrophysics Data System (ADS)

    Das, Pranab Kumar; Bhattacharyya, Amitava; Kulkarni, Ruta; Dhar, S. K.; Thamizhavel, A.

    2014-04-01

    A single crystal of PrSi was grown by the Czochralski method in a tetra-arc furnace. Powder x-ray diffraction of the as-grown crystal revealed that PrSi crystallizes in an FeB-type structure with space group Pnma (No. 62). The anisotropic magnetic properties were investigated by means of magnetic susceptibility, isothermal magnetization, electrical transport, and heat capacity measurements. Magnetic susceptibility data clearly indicate the ferromagnetic transition in PrSi with a TC of 52 K. The relative easy axis of magnetization was found to be the [010] direction. Heat capacity data confirm the bulk nature of the transition at 52 K and exhibit a huge anomaly at the transition. A sharp rise in the low-temperature heat capacity has been observed (below 5 K) which is attributed to the 141Pr nuclear Schottky heat capacity arising from the hyperfine field of the Pr moment. The estimated Pr magnetic moment 2.88 μB/Pr from the hyperfine splitting is in agreement with the saturation magnetization value obtained from the magnetization data measured at 2 K. From the crystal electric field analysis of the magnetic susceptibility, magnetization, and heat capacity data it is found that the degenerate J =4 Hund's rule derived state of the Pr3+ ion splits into nine singlets with an overall splitting of 284 K, the first excited singlet state separated by just 9 K from the ground state. The magnetic ordering in PrGe appears to be due to the exchange-generated admixture of low-lying crystal field levels. The magnetocaloric effect (MCE) has been investigated from magnetization data along all three principal crystallographic directions. The large magnetic entropy change, -ΔSM=22.2 J/kg K, and the relative cooling power, RCP = 460 J/kg, characteristic of the giant magnetocaloric effect are achieved near the transition temperature (TC = 52 K) for H = 70 kOe along [010]. Furthermore, the PrSi single crystal exhibits a giant MCE anisotropy.

  4. Technetium-99m labelling of the anti-tumour antibody PR1A3 by photoactivation.

    PubMed

    Stalteri, M A; Mather, S J

    1996-02-01

    Irradiation of antibody with ultraviolet light leads to reduction of disulphide bonds. Thus irradiation can be used to generate free thiols prior to direct labelling of antibody with technetium-99m, and has a potential advantage over methods using chemical reducing agents such as mercaptoethanol or tin, in that no purification step is needed to remove excess reducing agent. We have used the photoactivation method developed by Sykes et al. to label the anti-tumour antibody PR1A3 with 99mTc. The antibody was irradiated at 300 nm using a Rayonet photochemical reactor with eight RMR3000 lamps. In a typical experiment, the antibody solution was injected into a nitrogen-filled borosilicate glass vial and purged with nitrogen. A degassed solution containing stannous fluoride and methylene diphosphonate was then added to the antibody and the vial was irradiated. Following the irradiation, [99mTc]pertechnetate was injected into the vial and the reaction mixture was incubated for 30 min at room temperature before being analysed by size-exclusion high-pressure liquid chromatography and instant thin-layer chromatography. Labelling yields greater than 95% were obtained using antibody concentrations ranging from 0.5mg/ml to 5mg/ml. Irradiation times as short as 5 min and tin to antibody ratios in the range between 11 and 32 microg tin per mg antibody gave high labelling yields. Labelling yields greater than 95% were obtained after storage of the photoactivated antibody at -70 degrees C for several weeks. The stability of the 99mTc-labelled photoactivated PR1A3 was similar to that of 99mTc-labelled mercaptoethanol-reduced PR1A3. The mean immunoreactive fraction was 77% for the photoactivation-labelled PR1A3, compared to 93% for PR1A3 labelled by mercaptoethanol reduction. Biodistribution studies were carried out using 99mTc-photoactivation-labelled PR1A3 or PR1A3 labelled by mercaptoethanol reduction in Balb/c mice and in nude mice with MKN-45 human tumour xenografts. There was

  5. Anomalous Pr ordering and structural analysis for oxygenated tetragonal 1212 compound Pr{sub 1.5}Ba{sub 1.5}Cu{sub 3}O{sub 7.2}

    SciTech Connect

    Ku, H.C.; Luo, H.M.; Chi, Y.P.; Lin, B.N.; Hsu, Y.Y.; Lee, T.J.; Shi, J.B.; Kao, H.C.I.

    1999-11-01

    Magnetic measurement and powder X-ray Rietveld analysis are performed on oxygenated Pr{sub 1.5}Ba{sub 1.5}Cu{sub 3}O{sub 7.2} cuprate. This tetragonal compound with lattice parameters a = 0.38916 nm and C = 1.16177 nm is found to form the TlBa{sub 2}CaCu{sub 2}O{sub 7} 1212-type structure when written as Cu[Ba{sub 1.5}Pr{sub 0.5}]PrCu{sub 2}O{sub 7.2}. Low temperature magnetic data indicate that anomalous Pr order temperature T{sub N}(Pr) decreases from 18 K for orthorhombic PrBa{sub 2}Cu{sub 3}O{sub 6.9} to 10.5 K for Pr{sub 1.5}Ba{sub 1.5}Cu{sub 3}O{sub 7.2}. The increasing Pr-O bond length with decreasing T{sub N} indicates that Pr ordering is closely correlated with the wave function overlap between Pr-4f orbital and 0-2p{pi} orbital in the CuO{sub 2} bi-layers.

  6. Electrical PR Interval Variation Predicts New Occurrence of Atrial Fibrillation in Patients With Frequent Premature Atrial Contractions

    PubMed Central

    Chun, Kwang Jin; Hwang, Jin Kyung; Park, Seung-Jung; On, Young Keun; Kim, June Soo; Park, Kyoung-Min

    2016-01-01

    Abstract Atrial fibrillation (AF) is associated with the autonomic nervous system (ANS), and fluctuation of autonomic tone is more prominent in patients with AF. As autonomic tone affects the heart rate (HR), and there is an inverse relationship between HR and PR interval, PR interval variation could be greater in patients with AF than in those without AF. The purpose of this study was to investigate the correlation between PR interval variation and new-onset AF in patients with frequent PACs. We retrospectively enrolled 207 patients with frequent PACs who underwent electrocardiographs at least 4 times during the follow-up period. The PR variation was calculated by subtracting the minimum PR interval from the maximum PR interval. The outcomes were new occurrence of AF and all-cause mortality during the follow-up period. During a median follow-up of 8.3 years, 24 patients (11.6%) developed new-onset AF. Univariate analysis showed that prolonged PR interval (PR interval > 200 ms, P = 0.021), long PR variation (PR variation > 36.5 ms, P = 0.018), and PR variation (P = 0.004) as a continuous variable were associated with an increased risk of AF. Cox regression analysis showed that prolonged PR interval (hazard ratio = 3.321, 95% CI 1.064–10.362, P = 0.039) and PR variation (hazard ratio = 1.013, 95% CI 1.002–1.024, P = 0.022) were independent predictors for new-onset AF. However, PR variation and prolonged PR interval were not associated with all-cause mortality (P = 0.465 and 0.774, respectively). PR interval variation and prolonged PR interval are independent risk factors for new-onset AF in patients with frequent PACs. However we were unable to determine a cut-off value of PR interval variation for new-onset AF. PMID:27057868

  7. Role of the pharmacist in pre-exposure chemoprophylaxis (PrEP) therapy for HIV prevention.

    PubMed

    Clauson, Kevin A; Polen, Hyla H; Joseph, Shine A; Zapantis, Antonia

    2009-01-01

    With a global estimate of 2.5 million new infections of HIV occurring yearly, discovering novel methods to help stem the spread of the virus is critical. The use of antiretroviral chemoprophylaxis for preventing HIV after accidental or occupational exposure and in maternal to fetal transmission has become a widely accepted method to combat HIV. Based on this success, pre-exposure chemoprophylaxis (PrEP) is being explored in at-risk patient populations such as injecting drug users, female sex workers and men who have sex with men. This off-label and unmonitored use has created a need for education and intervention by pharmacists and other healthcare professionals. Pharmacists should educate themselves on PrEP and be prepared to counsel patients about their means of obtaining it (e.g. borrowing or sharing medications and ordering from disreputable Internet pharmacies). They should also be proactive about medication therapy management in these patients due to clinically important drug interactions with PrEP medications. Only one trial exploring the safety and efficacy of tenofovir as PrEP has been completed thus far. However, five ongoing trials are in various stages and two additional studies are scheduled for the near future. Unfortunately, studies in this arena have met with many challenges that have threatened to derail progress. Ethical controversy surrounding post-trial care of participants who seroconvert during studies, as well as concerns over emerging viral resistance and logistical site problems, have already halted several PrEP trials. Information about these early trials has already filtered down to affected individuals who are experimenting with this unproven therapy as an "evening before pill". The potential for PrEP is promising; however, more extensive trials are necessary to establish its safety and efficacy. Pharmacists are well-positioned to play a key role in helping patients make choices about PrEP, managing their therapy, and developing policy

  8. Autosomal-Recessive Hearing Impairment Due to Rare Missense Variants within S1PR2

    PubMed Central

    Santos-Cortez, Regie Lyn P.; Faridi, Rabia; Rehman, Atteeq U.; Lee, Kwanghyuk; Ansar, Muhammad; Wang, Xin; Morell, Robert J.; Isaacson, Rivka; Belyantseva, Inna A.; Dai, Hang; Acharya, Anushree; Qaiser, Tanveer A.; Muhammad, Dost; Ali, Rana Amjad; Shams, Sulaiman; Hassan, Muhammad Jawad; Shahzad, Shaheen; Raza, Syed Irfan; Bashir, Zil-e-Huma; Smith, Joshua D.; Nickerson, Deborah A.; Bamshad, Michael J.; Riazuddin, Sheikh; Ahmad, Wasim; Friedman, Thomas B.; Leal, Suzanne M.

    2016-01-01

    The sphingosine-1-phosphate receptors (S1PRs) are a well-studied class of transmembrane G protein-coupled sphingolipid receptors that mediate multiple cellular processes. However, S1PRs have not been previously reported to be involved in the genetic etiology of human traits. S1PR2 lies within the autosomal-recessive nonsyndromic hearing impairment (ARNSHI) locus DFNB68 on 19p13.2. From exome sequence data we identified two pathogenic S1PR2 variants, c.323G>C (p.Arg108Pro) and c.419A>G (p.Tyr140Cys). Each of these variants co-segregates with congenital profound hearing impairment in consanguineous Pakistani families with maximum LOD scores of 6.4 for family DEM4154 and 3.3 for family PKDF1400. Neither S1PR2 missense variant was reported among ∼120,000 chromosomes in the Exome Aggregation Consortium database, in 76 unrelated Pakistani exomes, or in 720 Pakistani control chromosomes. Both DNA variants affect highly conserved residues of S1PR2 and are predicted to be damaging by multiple bioinformatics tools. Molecular modeling predicts that these variants affect binding of sphingosine-1-phosphate (p.Arg108Pro) and G protein docking (p.Tyr140Cys). In the previously reported S1pr2−/− mice, stria vascularis abnormalities, organ of Corti degeneration, and profound hearing loss were observed. Additionally, hair cell defects were seen in both knockout mice and morphant zebrafish. Family PKDF1400 presents with ARNSHI, which is consistent with the lack of gross malformations in S1pr2−/− mice, whereas family DEM4154 has lower limb malformations in addition to hearing loss. Our findings suggest the possibility of developing therapies against hair cell damage (e.g., from ototoxic drugs) through targeted stimulation of S1PR2. PMID:26805784

  9. Magnetic and electromagnetic properties of Pr doped strontium ferrite/polyaniline composite film

    NASA Astrophysics Data System (ADS)

    Huang, Ying; Li, Yuqing; Wang, Yan

    2014-11-01

    This paper reported three acid (including hydrochloric acid HCl, p-toluenesulfonic acid PTS and D-camphor-10-acid CSA) doped SrPr0.2Fe11.8O19/PANI composite film and the HCl-PANI film prepared by a sol-gel method and in-situ oxidative polymerization. The characteristics of the film phase structure, surface morphology, conductivity and magnetic and electromagnetic properties were studied by using XRD, XPS, FESEM, four-probe tester, VSM and Vector Network Analyzer. The resistivity of organic acid doped composite films is higher than that of the HCl doped one. The saturation and remanent magnetization of PTS and HCl doped composite films are greater than the CSA-doped one; however, the coercivity of the three acid doped composite films is basically 5546 Oe. The saturation magnetization, remanent magnetization and coercivity of SrPr0.2Fe11.8O19 film are greater than those of the SrPr0.2Fe11.8O19-PANI composite film. In the frequency range of 8-12 GHz, the dielectric loss of HCl-PANI film is the maximum, and the dielectric loss of SrPr0.2Fe11.8O19 film is the minimum; the magnetic loss of the four films is in descending order as SrPr0.2Fe11.8O19 film, PrSrM/(HCl-PANI) composite film, PrSrM/(CSA-PANI) and HCl-PANI film.

  10. Characterization of coliphage PR772 and evaluation of its use for virus filter performance testing.

    PubMed

    Lute, Scott; Aranha, Hazel; Tremblay, Denise; Liang, Dehai; Ackermann, Hans-W; Chu, Benjamin; Moineau, Sylvain; Brorson, Kurt

    2004-08-01

    Virus filtration is a key clearance unit operation in the manufacture of recombinant protein, monoclonal antibody, and plasma-derived biopharmaceuticals. Recently, a consensus has developed among filter manufacturers and end users about the desirability of a common nomenclature and a standardized test for classifying and identifying virus-retentive filters. The Parenteral Drug Association virus filter task force has chosen PR772 as the model bacteriophage to standardize nomenclature for large-pore-size virus-retentive filters (filters designed to retain viruses larger than 50 to 60 nm in size). Previously, the coliphage PR772 (Tectiviridae family) has been used in some filtration studies as a surrogate for mammalian viruses of around 50 to 60 nm. In this report, we describe specific properties of PR772 critical to the support of its use for the standardization of virus filters. The complete genomic sequence of virulent phage PR772 was determined. Its genome contains 14,946 bp with an overall G+C content of 48.3 mol%, and 32 open reading frames of at least 40 codons. Comparison of the PR772 nucleotide sequence with the genome of Tectiviridae family prototype phage PRD1 revealed 97.2% identity at the DNA level. By dynamic light-scattering analysis, its hydrodynamic diameter was measured as 82 +/- 6 nm, consistent with use in testing large-virus-retentive filters. Finally, dynamic light-scattering analysis of PR772 preparations purified on CsCl gradients showed that the phage preparations are largely monodispersed. In summary, PR772 appears to be an appropriate model bacteriophage for standardization of nomenclature for larger-pore-size virus-retentive filters.

  11. Autosomal-Recessive Hearing Impairment Due to Rare Missense Variants within S1PR2.

    PubMed

    Santos-Cortez, Regie Lyn P; Faridi, Rabia; Rehman, Atteeq U; Lee, Kwanghyuk; Ansar, Muhammad; Wang, Xin; Morell, Robert J; Isaacson, Rivka; Belyantseva, Inna A; Dai, Hang; Acharya, Anushree; Qaiser, Tanveer A; Muhammad, Dost; Ali, Rana Amjad; Shams, Sulaiman; Hassan, Muhammad Jawad; Shahzad, Shaheen; Raza, Syed Irfan; Bashir, Zil-E-Huma; Smith, Joshua D; Nickerson, Deborah A; Bamshad, Michael J; Riazuddin, Sheikh; Ahmad, Wasim; Friedman, Thomas B; Leal, Suzanne M

    2016-02-01

    The sphingosine-1-phosphate receptors (S1PRs) are a well-studied class of transmembrane G protein-coupled sphingolipid receptors that mediate multiple cellular processes. However, S1PRs have not been previously reported to be involved in the genetic etiology of human traits. S1PR2 lies within the autosomal-recessive nonsyndromic hearing impairment (ARNSHI) locus DFNB68 on 19p13.2. From exome sequence data we identified two pathogenic S1PR2 variants, c.323G>C (p.Arg108Pro) and c.419A>G (p.Tyr140Cys). Each of these variants co-segregates with congenital profound hearing impairment in consanguineous Pakistani families with maximum LOD scores of 6.4 for family DEM4154 and 3.3 for family PKDF1400. Neither S1PR2 missense variant was reported among ∼120,000 chromosomes in the Exome Aggregation Consortium database, in 76 unrelated Pakistani exomes, or in 720 Pakistani control chromosomes. Both DNA variants affect highly conserved residues of S1PR2 and are predicted to be damaging by multiple bioinformatics tools. Molecular modeling predicts that these variants affect binding of sphingosine-1-phosphate (p.Arg108Pro) and G protein docking (p.Tyr140Cys). In the previously reported S1pr2(-/-) mice, stria vascularis abnormalities, organ of Corti degeneration, and profound hearing loss were observed. Additionally, hair cell defects were seen in both knockout mice and morphant zebrafish. Family PKDF1400 presents with ARNSHI, which is consistent with the lack of gross malformations in S1pr2(-/-) mice, whereas family DEM4154 has lower limb malformations in addition to hearing loss. Our findings suggest the possibility of developing therapies against hair cell damage (e.g., from ototoxic drugs) through targeted stimulation of S1PR2. PMID:26805784

  12. Characterization of coliphage PR772 and evaluation of its use for virus filter performance testing.

    PubMed

    Lute, Scott; Aranha, Hazel; Tremblay, Denise; Liang, Dehai; Ackermann, Hans-W; Chu, Benjamin; Moineau, Sylvain; Brorson, Kurt

    2004-08-01

    Virus filtration is a key clearance unit operation in the manufacture of recombinant protein, monoclonal antibody, and plasma-derived biopharmaceuticals. Recently, a consensus has developed among filter manufacturers and end users about the desirability of a common nomenclature and a standardized test for classifying and identifying virus-retentive filters. The Parenteral Drug Association virus filter task force has chosen PR772 as the model bacteriophage to standardize nomenclature for large-pore-size virus-retentive filters (filters designed to retain viruses larger than 50 to 60 nm in size). Previously, the coliphage PR772 (Tectiviridae family) has been used in some filtration studies as a surrogate for mammalian viruses of around 50 to 60 nm. In this report, we describe specific properties of PR772 critical to the support of its use for the standardization of virus filters. The complete genomic sequence of virulent phage PR772 was determined. Its genome contains 14,946 bp with an overall G+C content of 48.3 mol%, and 32 open reading frames of at least 40 codons. Comparison of the PR772 nucleotide sequence with the genome of Tectiviridae family prototype phage PRD1 revealed 97.2% identity at the DNA level. By dynamic light-scattering analysis, its hydrodynamic diameter was measured as 82 +/- 6 nm, consistent with use in testing large-virus-retentive filters. Finally, dynamic light-scattering analysis of PR772 preparations purified on CsCl gradients showed that the phage preparations are largely monodispersed. In summary, PR772 appears to be an appropriate model bacteriophage for standardization of nomenclature for larger-pore-size virus-retentive filters. PMID:15294825

  13. Characterization of Coliphage PR772 and Evaluation of Its Use for Virus Filter Performance Testing

    PubMed Central

    Lute, Scott; Aranha, Hazel; Tremblay, Denise; Liang, Dehai; Ackermann, Hans-W.; Chu, Benjamin; Moineau, Sylvain; Brorson, Kurt

    2004-01-01

    Virus filtration is a key clearance unit operation in the manufacture of recombinant protein, monoclonal antibody, and plasma-derived biopharmaceuticals. Recently, a consensus has developed among filter manufacturers and end users about the desirability of a common nomenclature and a standardized test for classifying and identifying virus-retentive filters. The Parenteral Drug Association virus filter task force has chosen PR772 as the model bacteriophage to standardize nomenclature for large-pore-size virus-retentive filters (filters designed to retain viruses larger than 50 to 60 nm in size). Previously, the coliphage PR772 (Tectiviridae family) has been used in some filtration studies as a surrogate for mammalian viruses of around 50 to 60 nm. In this report, we describe specific properties of PR772 critical to the support of its use for the standardization of virus filters. The complete genomic sequence of virulent phage PR772 was determined. Its genome contains 14,946 bp with an overall G+C content of 48.3 mol%, and 32 open reading frames of at least 40 codons. Comparison of the PR772 nucleotide sequence with the genome of Tectiviridae family prototype phage PRD1 revealed 97.2% identity at the DNA level. By dynamic light-scattering analysis, its hydrodynamic diameter was measured as 82 ± 6 nm, consistent with use in testing large-virus-retentive filters. Finally, dynamic light-scattering analysis of PR772 preparations purified on CsCl gradients showed that the phage preparations are largely monodispersed. In summary, PR772 appears to be an appropriate model bacteriophage for standardization of nomenclature for larger-pore-size virus-retentive filters. PMID:15294825

  14. Templating Influence of Molecular Precursors on Pr(OH)3 Nanostructures.

    PubMed

    Hemmer, Eva; Cavelius, Christian; Huch, Volker; Mathur, Sanjay

    2015-07-01

    Four new praseodymium alkoxo and amido compounds ([Pr3(μ3-OtBu)2(μ2-OtBu)3(OtBu)4(HOtBu)2] (1), [Pr{OC(tBu)3}3(THF)] (2), [PrCl{N(SiMe3)2}2(THF)]2 (3), and [PrCl{OC(tBu)3}2(THF)]2 (4)) were synthesized and structurally characterized by single-crystal X-ray diffraction analysis. Application of these compounds in solvothermal synthesis of praseodymium oxide/hydroxide nanostructures showed their templating influence on the morphology and phase composition of the resulting solid-state materials. Differential reactivity of the chosen alkoxide ligands toward water and the different arrangements of metal-oxygen units in the studied precursor compounds strongly influenced the kinetics of hydrolysis and cross-condensation reactions as manifested in the morphological changes and phase composition of the final products. Thermal decomposition studies of 1-4 confirmed their conversion into the corresponding oxide phases. Activation of compounds 1, 2, and 4 by either a base or a stoichiometric amount of water showed the distinct influence of their chemical configuration on the obtained nanopowders: whereas 1 solely produced nanorods of Pr(OH)3, 2 predominantly formed a mixture of rod-shaped and spherical particles. The solvothermal decomposition of 4 resulted in Pr(OH)2Cl or PrOCl due to the presence of Cl ligands in the molecular precursor. The resultant materials were thoroughly characterized to demonstrate the relationship between precursor chemistry and the processing parameters that are clearly manifested in the morphology and phase of the final ceramics. PMID:26068779

  15. A Desulfitobacterium sp. strain PR reductively dechlorinates both 1,1,1-trichloroethane and chloroform.

    PubMed

    Ding, Chang; Zhao, Siyan; He, Jianzhong

    2014-11-01

    1,1,1-Trichloroethane (TCA) and chloroform are two notorious groundwater pollutants. Here we report the isolation and characterization of Desulfitobacterium sp. strain PR that rapidly dechlorinates both compounds. In pyruvate-amended medium, strain PR reductively dechlorinates ∼ 1.0 mM TCA completely to monochloroethane within 15 days. Under the same conditions, strain PR dechlorinates ∼ 1.2 mM chloroform to predominantly dichloromethane (∼ 1.14 mM) and trace amount of monochloromethane (∼ 0.06 mM) within 10 days. Strain PR shares 96.7% 16S rRNA gene sequence similarity with its closest relative - Desulfitobacterium metallireducens strain 853-15; however, it distinguishes itself from known Desulfitobacterium strains by its inability of utilizing several of their commonly shared substrates such as lactate, thiosulfate and sulfite. A reductive dehalogenase gene (ctrA) in strain PR was identified to be responsible for dechlorination of both TCA and chloroform, showing a maximum expression level of 5.95 ∼ 6.25 copies of transcripts cell(-1) . CtrA shares 94% amino acid sequence identity with CfrA in Dehalobacter sp. strain CF50 and DcrA in Dehalobacter sp. strain DCA. Interestingly, strain PR could tolerate high aqueous concentrations (up to 0.45 mM) of trichloroethene, another groundwater pollutant that often coexists with TCA/chloroform. As the first chloroform-respiring and the second TCA-respiring isolate that has been identified, Desulfitobacterium sp. strain PR may prove useful in remediation of halogenated alkanes with trihalomethyl (-CX₃) groups.

  16. A novel role of PR2 in abscisic acid (ABA) mediated, pathogen-induced callose deposition in Arabidopsis thaliana.

    PubMed

    Oide, Shinichi; Bejai, Sarosh; Staal, Jens; Guan, Na; Kaliff, Maria; Dixelius, Christina

    2013-12-01

    Pathogenesis-related protein 2 (PR2) is known to play a major role in plant defense and general stress responses. Resistance against the fungal pathogen Leptosphaeria maculans in Arabidopsis requires abscisic acid (ABA), which promotes the deposition of callose, a β-1,3-glucan polymer. Here, we examined the role of PR2 in callose deposition in relation to ABA treatment and challenge with L. maculans and Pseudomonas syringae. Characterization of PR2-overexpressing plants and the knockout line indicated that PR2 negatively affects callose deposition. Recombinant PR2 purified from Pichia pastoris showed callose-degrading activity, and a considerable reduction in the callose-degrading activity was observed in the leaf extract of the PR2 knockout line compared with the wild-type. ABA pretreatment before challenge with L. maculans concomitantly repressed PR2 and enhanced callose accumulation. Likewise, overexpression of an ABA biosynthesis gene NCED3 resulted in reduced PR2 expression and increased callose deposition. We propose that ABA promotes callose deposition through the transcriptional repression of PR2 in Arabidopsis challenged by L. maculans and P. syringae. Callose by itself is likely to act antagonistically on salicylic acid (SA) defense signaling, suggesting that PR2 may function as a modulator of callose- and SA-dependent defense responses.

  17. Evaluation of critical distances for energy transfer between Pr3+ and Ce3+ in yttrium aluminium garnet

    NASA Astrophysics Data System (ADS)

    Zeng, Peng; Wei, Xiantao; Zhou, Shaoshuai; Yin, Min; Chen, Yonghu

    2016-09-01

    A series of Pr3+/Ce3+ doped yttrium aluminium garnet (Y3Al5O12 or simply YAG) phosphors were synthesized to investigate the energy transfer between Pr3+ and Ce3+ for their potential application in a white light-emitting diode and quantum information storage and processing. The excitation and emission spectra of YAG:Pr3+/Ce3+ were measured and analyzed, and it revealed that the reabsorption between Pr3+ and Ce3+ was so weak that it can be ignored, and the energy transfer from Pr3+ (5d) to Ce3+ (5d) and Ce3+ (5d) to Pr3+ (1D2) did occur. By analyzing the excitation and the emission spectra, the energy transfer from Pr3+ (5d) to Ce3+ (5d) and Ce3+ (5d) to Pr3+ (1D2) was examined in detail with an original strategy deduced from fluorescence dynamics and the Dexter energy transfer theory, and the critical distances of energy transfer were derived to be 7.9 Å and 4.0 Å for Pr3+ (5d) to Ce3+ (5d) and Ce3+ (5d) to Pr3+ (1D2), respectively. The energy transfer rates of the two processes of various concentrations were discussed and evaluated. Furthermore, for the purpose of sensing a single Pr3+ state with a Ce3+ ion, the optimal distance of Ce3+ from Pr3+ was evaluated as 5.60 Å, where the probability of success reaches its maximum value of 78.66%, and meanwhile the probabilities were evaluated for a series of Y3+ sites in a YAG lattice. These results will be of valuable reference for achievement of the optimal energy transfer efficiency in Pr3+/Ce3+ doped YAG and other similar systems.

  18. Phylogenetic analysis of PR genes in some pome fruit species with the emphasis on transcriptional analysis and ROS response under Erwinia amylovora inoculation in apple.

    PubMed

    Hassani, Maryam; Salami, Seyed Alireza; Nasiri, Jaber; Abdollahi, Hamid; Ghahremani, Zahra

    2016-02-01

    Attempts were made to identify eight pathogenesis related (PR) genes (i.e., PR-1a, PR3-ch1, PR3-Ch2, PR3-Ch3, PR3-Ch4, PR3-Ch5, PR-5 and PR-8) from 27 genotypes of apple, quince and pear, which are induced in response to inoculation with the pathogen Erwinia amylovora, the causal agent of fire blight. Totally, 32 PR genes of different families were obtained, excepting PR3-Ch2 (amplified only in apple) and PR3-Ch4 (amplified only in apple and pear), the others were successfully amplified in all the genotypes of apple, quince and pear. Evolutionary, the genes of each family exhibited significant homology with each other, as the corresponded phylogenetic neighbor-joining-based dendrograms were taken into consideration. Meanwhile, according to the expression assay, it was deduced that the pathogen activity can significantly affect the expression levels of some selected PR genes of PR3-Ch2, PR3-Ch4, PR3-Ch5 and particularly Cat I in both resistant (MM-111) and semi-susceptible (MM-106) apple rootstocks. Lastly, it was concluded that the pathogen E. amylovora is able to stimulate ROS response, particularly using generation of hydrogen peroxide (H2O2) in both aforementioned apple rootstock. PMID:26589211

  19. Novel epitopes identified by Anti-PrP monoclonal antibodies produced following immunization of Prnp0/0 Balb/cJ mice with purified scrapie prions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prions, or infectious proteins, cause a class of uniformly fatal neurodegenerative diseases. Prions are composed solely of an aberrantly folded isoform(PrPSc)of a normal cellular protein (PrPC). Shared sequence identity of PrPSc with PrPC has limited the detection sensitivity of immunochemical assay...

  20. Phylogenetic analysis of PR genes in some pome fruit species with the emphasis on transcriptional analysis and ROS response under Erwinia amylovora inoculation in apple.

    PubMed

    Hassani, Maryam; Salami, Seyed Alireza; Nasiri, Jaber; Abdollahi, Hamid; Ghahremani, Zahra

    2016-02-01

    Attempts were made to identify eight pathogenesis related (PR) genes (i.e., PR-1a, PR3-ch1, PR3-Ch2, PR3-Ch3, PR3-Ch4, PR3-Ch5, PR-5 and PR-8) from 27 genotypes of apple, quince and pear, which are induced in response to inoculation with the pathogen Erwinia amylovora, the causal agent of fire blight. Totally, 32 PR genes of different families were obtained, excepting PR3-Ch2 (amplified only in apple) and PR3-Ch4 (amplified only in apple and pear), the others were successfully amplified in all the genotypes of apple, quince and pear. Evolutionary, the genes of each family exhibited significant homology with each other, as the corresponded phylogenetic neighbor-joining-based dendrograms were taken into consideration. Meanwhile, according to the expression assay, it was deduced that the pathogen activity can significantly affect the expression levels of some selected PR genes of PR3-Ch2, PR3-Ch4, PR3-Ch5 and particularly Cat I in both resistant (MM-111) and semi-susceptible (MM-106) apple rootstocks. Lastly, it was concluded that the pathogen E. amylovora is able to stimulate ROS response, particularly using generation of hydrogen peroxide (H2O2) in both aforementioned apple rootstock.

  1. Magnetic properties of the intermetallic compounds PrNiSn and NdNiSn

    NASA Astrophysics Data System (ADS)

    Beirne, Eamonn Daniel

    Inelastic neutron scattering has been used to determine the crystalline electric field (CEF) excitations in the intermetallic compound PrNiSn. Polycrystalline samples of PiNiSn are found to have 7 excitations up to 30 meV, with strong low-lying modes at 2.0, 3.5, and 5.1 meV. The site symmetry of Pr3+ in this system is such that the degeneracy of the 9 levels in the J = 4 ground state multiplet is removed completely by the crystal field. From fitting this data, it is clear that the ground state is a singlet that couples to each of the other 8 excited states. The wavefunctions of the levels are determined and a level scheme proposed for this material. Inelastic scattering results are also presented for a single crystal of PrNiSn. The dispersion of the low-lying E = 3.5 meV CEF excitation is documented, showing 4 distinct modes corresponding to the 4 Pr ions in the unit cell. Susceptibility and magnetisation results for PrNiSn and NdNiSn are presented. From these measurements it is clear that the PrNiSn does not order magnetically down to 2K, whereas NdNiSn has an antifenomagnetic transition at TN = 3.1K. Resistivity measurements on PrNiSn also show no evidence of a magnetic transition, but there are gradient changes at around 4.5K and 12K. This corresponds to a local maximum at 12K and local minimum at 4.5K along the b-axis in this compound. Measurements on single crystals of these compounds show strong anisotropy in both cases, attributed to CEF effects. From the proposed CEF level scheme, the bulk properties such as the susceptibility can be modelled. Neutron powder diffraction measurements on both PrNiSn and NdNiSn confirm that there is no magnetic transition down to 1.6K in PrNiSn, and TN is confirmed for NdNiSn. Structural Rietveld fitting confirms the room temperature orthorhombic structure in both systems down to low temperature, but the magnetic structure of NdNiSn can not be determined. This is due to the magnetic peaks below TN doubling up, indicating a

  2. Rethinking HIV prevention to prepare for oral PrEP implementation for young African women

    PubMed Central

    Celum, Connie L; Delany-Moretlwe, Sinead; McConnell, Margaret; van Rooyen, Heidi; Bekker, Linda-Gail; Kurth, Ann; Bukusi, Elizabeth; Desmond, Chris; Morton, Jennifer; Baeten, Jared M

    2015-01-01

    Introduction HIV incidence remains high among young women in sub-Saharan Africa in spite of scale-up of HIV testing, behavioural interventions, antiretroviral treatment and medical male circumcision. There is a critical need to critique past approaches and learn about the most effective implementation of evidence-based HIV prevention strategies, particularly emerging interventions such as pre-exposure prophylaxis (PrEP). Discussion Women in sub-Saharan Africa are at increased risk of HIV during adolescence and into their 20s, in part due to contextual factors including gender norms and relationship dynamics, and limited access to reproductive and sexual health services. We reviewed behavioural, behavioural economic and biomedical approaches to HIV prevention for young African women, with a particular focus on the barriers, opportunities and implications for implementing PrEP in this group. Behavioural interventions have had limited impact in part due to not effectively addressing the context, broader sexual norms and expectations, and structural factors that increase risk and vulnerability. Of biomedical HIV prevention strategies that have been tested, daily oral PrEP has the greatest evidence for protection, although adherence was low in two placebo-controlled trials in young African women. Given high efficacy and effectiveness in other populations, demonstration projects of open-label PrEP in young African women are needed to determine the most effective delivery models and whether women at substantial risk are motivated and able to use oral PrEP with sufficient adherence to achieve HIV prevention benefits. Conclusions Social marketing, adherence support and behavioural economic interventions should be evaluated as part of PrEP demonstration projects among young African women in terms of their effectiveness in increasing demand and optimizing uptake and effective use of PrEP. Lessons learned through evaluations of implementation strategies for delivering oral Pr

  3. ROS-scavenger and radioprotective efficacy of the new PrC-210 aminothiol.

    PubMed

    Peebles, Daniel D; Soref, Cheryl M; Copp, Richard R; Thunberg, Allen L; Fahl, William E

    2012-07-01

    To identify new aminothiol radioprotectors that are active when applied topically and have fewer side effects when administered systemically, a new family of aminothiol radioprotectors was designed and synthesized. Three key elements in the aminothiol design were, (1) small size for efficient transmembrane diffusion, (2) positive charged amines in alkyl backbone for strong ionic interaction with DNA backbone, and (3) a perpendicular, alkyl side-chain with a terminal thiol that is projected away from the DNA backbone to enable reactive oxygen species scavenging around DNA. Several in vitro assays were used to characterize the prototype aminothiol, PrC-210, for efficacy: protection against reactive oxygen species-induced plasmid DNA nicking, mass spectrometry to detect aminothiol-reactive oxygen species by-products, S. typhimurium mutagenesis, human cell growth inhibition, Western blot for p21 expression, and FACS analysis. Additionally, two in vivo assays were used to assess radioprotective efficacy; a Sprague-Dawley rat dorsal skin radiodermatitis assay was developed to screen for aminothiol efficacy when topically applied, and ICR mouse survival was scored after systemic PrC-210 administration and whole-body radiation. PrC-210 efficiently scavenged reactive oxygen species and completely protected supercoiled plasmid DNA against reactive oxygen species-induced damage. Neither PrC-210 nor its analog PrC-211 were bacterial mutagens. In cell culture, PrC-210 application to diploid human fibroblasts showed: (1) inhibition of cell growth with an IC(70) of 4.1 mM, (2) induced levels of p21 expression, and (3) a G(1)/S-cell cycle block that was reversed after washout of PrC-210-containing medium. In rodents, PrC-210 was an effective radioprotector showing: (1) complete prevention of Grade 2-3 radiodermatitis when applied topically (370 mM in ethanol:propylene glycol:water solution) prior to skin irradiation, (2) complete prevention of Grade 2-3 radiodermatitis when

  4. Effects of Pr on Optimal Heat Transport in Rayleigh-Bénard Convection

    NASA Astrophysics Data System (ADS)

    Sondak, David; Budišić, Marko; Waleffe, Fabian; Smith, Leslie

    2015-11-01

    Steady flows that optimize heat transport are obtained for two-dimensional Rayleigh-Bénard convection with no-slip horizontal walls for a variety of Prandtl numbers Pr and Rayleigh number up to Ra ~109 . The presence of two local maxima of Nu with different horizontal wavenumbers at the same Ra leads to the emergence of two different flow structures as candidates for optimizing the heat transport where the Nusselt number Nu is a non-dimensional measure of the vertical heat transport. For Pr <= 7 , optimal transport is achieved at the smaller maximal wavenumber whereas for Pr > 7 at high-enough Ra the optimal structure occurs at the larger maximal wavenumber. Three regions are observed in the optimal mean temperature profiles, T y : 1.) d T / dy < 0 in the boundary layers, 2.) d T / dy > 0 (Pr <= 7) or d T / dy < 0 (Pr > 7) in the central region, and 3.) d T / dy > 0 between the boundary layers and central region. We also search for a signature of these optimal structures in a fully-developed turbulent flow by employing modal decompositions such as the proper orthogonal decomposition and the Koopman mode decomposition. Partial support from NSF-DMS grant 1147523 is gratefully acknowledged.

  5. Microstructure and optical properties of Pr3+-doped hafnium silicate films.

    PubMed

    An, Yongtao; Labbé, Christophe; Khomenkova, Larysa; Morales, Magali; Portier, Xavier; Gourbilleau, Fabrice

    2013-01-21

    In this study, we report on the evolution of the microstructure and photoluminescence properties of Pr3+-doped hafnium silicate thin films as a function of annealing temperature (TA). The composition and microstructure of the films were characterized by means of Rutherford backscattering spectrometry, spectroscopic ellipsometry, Fourier transform infrared absorption, and X-ray diffraction, while the emission properties have been studied by means of photoluminescence (PL) and PL excitation (PLE) spectroscopies. It was observed that a post-annealing treatment favors the phase separation in hafnium silicate matrix being more evident at 950°C. The HfO2 phase demonstrates a pronounced crystallization in tetragonal phase upon 950°C annealing. Pr3+ emission appeared at TA = 950°C, and the highest efficiency of Pr3+ ion emission was detected upon a thermal treatment at 1,000°C. Analysis of the PLE spectra reveals an efficient energy transfer from matrix defects towards Pr3+ ions. It is considered that oxygen vacancies act as effective Pr3+ sensitizer. Finally, a PL study of undoped HfO2 and HfSiOx matrices is performed to evidence the energy transfer.

  6. Biological implications of somatic DDX41 p.R525H mutation in acute myeloid leukemia.

    PubMed

    Kadono, Moe; Kanai, Akinori; Nagamachi, Akiko; Shinriki, Satoru; Kawata, Jin; Iwato, Koji; Kyo, Taiichi; Oshima, Kumi; Yokoyama, Akihiko; Kawamura, Takeshi; Nagase, Reina; Inoue, Daichi; Kitamura, Toshio; Inaba, Toshiya; Ichinohe, Tatsuo; Matsui, Hirotaka

    2016-08-01

    The DDX41 gene, encoding a DEAD-box type ATP-dependent RNA helicase, is rarely but reproducibly mutated in myeloid diseases. The acquired mutation in DDX41 is highly concentrated at c.G1574A (p.R525H) in the conserved motif VI located at the C-terminus of the helicase core domain where ATP interacts and is hydrolyzed. Therefore, it is likely that the p.R525H mutation perturbs ATPase activity in a dominant-negative manner. In this study, we screened for the DDX41 mutation of CD34-positive tumor cells based on mRNA sequencing and identified the p.R525H mutation in three cases among 23 patients. Intriguingly, these patients commonly exhibited acute myeloid leukemia (AML) with peripheral blood cytopenias and low blast counts, suggesting that the mutation inhibits the growth and differentiation of hematopoietic cells. Data from cord blood cells and leukemia cell lines suggest a role for DDX41 in preribosomal RNA processing, in which the expression of the p.R525H mutant causes a certain ribosomopathy phenotype in hematopoietic cells by suppressing MDM2-mediated RB degradation, thus triggering the inhibition of E2F activity. This study uncovered a pathogenic role of p.R525H DDX41 in the slow growth rate of tumor cells. Age-dependent epigenetic alterations or other somatic changes might collaborate with the mutation to cause AML.

  7. Protein phosphatase 2A subunit PR70 interacts with pRb and mediates its dephosphorylation.

    PubMed

    Magenta, Alessandra; Fasanaro, Pasquale; Romani, Sveva; Di Stefano, Valeria; Capogrossi, Maurizio C; Martelli, Fabio

    2008-01-01

    The retinoblastoma tumor suppressor protein (pRb) regulates cell proliferation and differentiation via phosphorylation-sensitive interactions with specific targets. While the role of cyclin/cyclin-dependent kinase complexes in the modulation of pRb phosphorylation has been extensively studied, relatively little is known about the molecular mechanisms regulating phosphate removal by phosphatases. Protein phosphatase 2A (PP2A) is constituted by a core dimer bearing catalytic activity and one variable B regulatory subunit conferring target specificity and subcellular localization. We previously demonstrated that PP2A core dimer binds pRb and dephosphorylates pRb upon oxidative stress. In the present study, we identified a specific PP2A-B subunit, PR70, that was associated with pRb both in vitro and in vivo. PR70 overexpression caused pRb dephosphorylation; conversely, PR70 knockdown prevented both pRb dephosphorylation and DNA synthesis inhibition induced by oxidative stress. Moreover, we found that intracellular Ca(2+) mobilization was necessary and sufficient to trigger pRb dephosphorylation and PP2A phosphatase activity of PR70 was Ca(2+) induced. These data underline the importance of PR70-Ca(2+) interaction in the signal transduction mechanisms triggered by redox imbalance and leading to pRb dephosphorylation.

  8. Structural Studies of Truncated Forms of the Prion Protein PrP

    PubMed Central

    Wan, William; Wille, Holger; Stöhr, Jan; Kendall, Amy; Bian, Wen; McDonald, Michele; Tiggelaar, Sarah; Watts, Joel C.; Prusiner, Stanley B.; Stubbs, Gerald

    2015-01-01

    Prions are proteins that adopt self-propagating aberrant folds. The self-propagating properties of prions are a direct consequence of their distinct structures, making the understanding of these structures and their biophysical interactions fundamental to understanding prions and their related diseases. The insolubility and inherent disorder of prions have made their structures difficult to study, particularly in the case of the infectious form of the mammalian prion protein PrP. Many investigators have therefore preferred to work with peptide fragments of PrP, suggesting that these peptides might serve as structural and functional models for biologically active prions. We have used x-ray fiber diffraction to compare a series of different-sized fragments of PrP, to determine the structural commonalities among the fragments and the biologically active, self-propagating prions. Although all of the peptides studied adopted amyloid conformations, only the larger fragments demonstrated a degree of structural complexity approaching that of PrP. Even these larger fragments did not adopt the prion structure itself with detailed fidelity, and in some cases their structures were radically different from that of pathogenic PrPSc. PMID:25809267

  9. Activation of p53-regulated pro-apoptotic signaling pathways in PrP-mediated myopathy

    PubMed Central

    Liang, Jingjing; Parchaliuk, Debra; Medina, Sarah; Sorensen, Garrett; Landry, Laura; Huang, Shenghai; Wang, Meiling; Kong, Qingzhong; Booth, Stephanie A

    2009-01-01

    Background We have reported that doxycycline-induced over-expression of wild type prion protein (PrP) in skeletal muscles of Tg(HQK) mice is sufficient to cause a primary myopathy with no signs of peripheral neuropathy. The preferential accumulation of the truncated PrP C1 fragment was closely correlated with these myopathic changes. In this study we use gene expression profiling to explore the temporal program of molecular changes underlying the PrP-mediated myopathy. Results We used DNA microarrays, and confirmatory real-time PCR and Western blot analysis to demonstrate deregulation of a large number of genes in the course of the progressive myopathy in the skeletal muscles of doxycycline-treated Tg(HQK) mice. These include the down-regulation of genes coding for the myofibrillar proteins and transcription factor MEF2c, and up-regulation of genes for lysosomal proteins that is concomitant with increased lysosomal activity in the skeletal muscles. Significantly, there was prominent up-regulation of p53 and p53-regulated genes involved in cell cycle arrest and promotion of apoptosis that paralleled the initiation and progression of the muscle pathology. Conclusion The data provides the first in vivo evidence that directly links p53 to a wild type PrP-mediated disease. It is evident that several mechanistic features contribute to the myopathy observed in PrP over-expressing mice and that p53-related apoptotic pathways appear to play a major role. PMID:19400950

  10. Microstructure and optical properties of Pr3+-doped hafnium silicate films

    PubMed Central

    2013-01-01

    In this study, we report on the evolution of the microstructure and photoluminescence properties of Pr3+-doped hafnium silicate thin films as a function of annealing temperature (TA). The composition and microstructure of the films were characterized by means of Rutherford backscattering spectrometry, spectroscopic ellipsometry, Fourier transform infrared absorption, and X-ray diffraction, while the emission properties have been studied by means of photoluminescence (PL) and PL excitation (PLE) spectroscopies. It was observed that a post-annealing treatment favors the phase separation in hafnium silicate matrix being more evident at 950°C. The HfO2 phase demonstrates a pronounced crystallization in tetragonal phase upon 950°C annealing. Pr3+ emission appeared at TA = 950°C, and the highest efficiency of Pr3+ ion emission was detected upon a thermal treatment at 1,000°C. Analysis of the PLE spectra reveals an efficient energy transfer from matrix defects towards Pr3+ ions. It is considered that oxygen vacancies act as effective Pr3+ sensitizer. Finally, a PL study of undoped HfO2 and HfSiOx matrices is performed to evidence the energy transfer. PMID:23336520

  11. Biological implications of somatic DDX41 p.R525H mutation in acute myeloid leukemia.

    PubMed

    Kadono, Moe; Kanai, Akinori; Nagamachi, Akiko; Shinriki, Satoru; Kawata, Jin; Iwato, Koji; Kyo, Taiichi; Oshima, Kumi; Yokoyama, Akihiko; Kawamura, Takeshi; Nagase, Reina; Inoue, Daichi; Kitamura, Toshio; Inaba, Toshiya; Ichinohe, Tatsuo; Matsui, Hirotaka

    2016-08-01

    The DDX41 gene, encoding a DEAD-box type ATP-dependent RNA helicase, is rarely but reproducibly mutated in myeloid diseases. The acquired mutation in DDX41 is highly concentrated at c.G1574A (p.R525H) in the conserved motif VI located at the C-terminus of the helicase core domain where ATP interacts and is hydrolyzed. Therefore, it is likely that the p.R525H mutation perturbs ATPase activity in a dominant-negative manner. In this study, we screened for the DDX41 mutation of CD34-positive tumor cells based on mRNA sequencing and identified the p.R525H mutation in three cases among 23 patients. Intriguingly, these patients commonly exhibited acute myeloid leukemia (AML) with peripheral blood cytopenias and low blast counts, suggesting that the mutation inhibits the growth and differentiation of hematopoietic cells. Data from cord blood cells and leukemia cell lines suggest a role for DDX41 in preribosomal RNA processing, in which the expression of the p.R525H mutant causes a certain ribosomopathy phenotype in hematopoietic cells by suppressing MDM2-mediated RB degradation, thus triggering the inhibition of E2F activity. This study uncovered a pathogenic role of p.R525H DDX41 in the slow growth rate of tumor cells. Age-dependent epigenetic alterations or other somatic changes might collaborate with the mutation to cause AML. PMID:27174803

  12. Developmental expression of PrP in the post-implantation embryo

    PubMed Central

    Tremblay, Patrick; Bouzamondo-Bernstein, Essia; Heinrich, Cornelia; Prusiner, Stanley B.; DeArmond, Stephen J.

    2009-01-01

    Since prion protein (PrP) mRNA and PrPC expression levels in transgenic (Tg) mice using the CosSHa.tet vector correlate well with the PrP transgene copy, we constructed Prnp-LacZ Tg animals expressing β-galactosidase that was inserted into the CosSHa.tet vector. The CosSHa.tet vector was created from a large PrP cosmid clone in which the PrP open reading frame was deleted. In the developing nervous system, the β-galactosidase marker was not expressed in the neural progenitors of the mitotically active ventricular zone. It is first expressed in cells that have ceased proliferating, migrated radially from the ventricular zone, and differentiated into neurons in the intermediate layer. At E11.5 p.c., motor neurons in the ventral neural tube clearly express the marker transgene. Expression in dorsal neural tube neurons is observed at later stages, after their differentiation. These results indicate that Prnp gene expression in the nervous system begins in post-mitotic neural cells that have undergone neuronal differentiation. This pattern of Prnp expression in the nervous system appears to persist throughout the adult life of mammals. PMID:17292334

  13. Estrogen and progesterone receptors have distinct roles in the establishment of the hyperplastic phenotype in PR-A transgenic mice

    SciTech Connect

    Simian, Marina; Bissell, Mina J.; Barcellos-Hoff, Mary Helen; Shyamala, Gopalan

    2009-05-11

    Expression of the A and B forms of progesterone receptor (PR) in an appropriate ratio is critical for mammary development. Mammary glands of PR-A transgenic mice, carrying an additional A form of PR as a transgene, exhibit morphological features associated with the development of mammary tumors. Our objective was to determine the roles of estrogen (E) and progesterone (P) in the genesis of mammary hyperplasias/preneoplasias in PR-A transgenics. We subjected PR-A mice to hormonal treatments and analyzed mammary glands for the presence of hyperplasias and used BrdU incorporation to measure proliferation. Quantitative image analysis was carried out to compare levels of latency-associated peptide and transforming growth factor beta 1 (TGF{beta}1) between PR-A and PR-B transgenics. Basement membrane disruption was examined by immunofluorescence and proteolytic activity by zymography. The hyperplastic phenotype of PR-A transgenics is inhibited by ovariectomy, and is reversed by treatment with E + P. Studies using the antiestrogen ICI 182,780 or antiprogestins RU486 or ZK 98,299 show that the increase in proliferation requires signaling through E/estrogen receptor alpha but is not sufficient to give rise to hyperplasias, whereas signaling through P/PR has little impact on proliferation but is essential for the manifestation of hyperplasias. Increased proliferation is correlated with decreased TGF{beta}1 activation in the PR-A transgenics. Analysis of basement membrane integrity showed loss of laminin-5, collagen III and collagen IV in mammary glands of PR-A mice, which is restored by ovariectomy. Examination of matrix metalloproteases (MMPs) showed that total levels of MMP-2 correlate with the steady-state levels of PR, and that areas of laminin-5 loss coincide with those of activation of MMP-2 in PR-A transgenics. Activation of MMP-2 is dependent on treatment with E and P in ovariectomized wild-type mice, but is achieved only by treatment with P in PR-A mice. These data

  14. Diversity in genomic organisation, developmental regulation and distribution of the murine PR72/B" subunits of protein phosphatase 2A

    PubMed Central

    Zwaenepoel, Karen; Louis, Justin V; Goris, Jozef; Janssens, Veerle

    2008-01-01

    Background Protein phosphatase 2A (PP2A) is a serine/threonine-specific phosphatase displaying vital functions in growth and development through its role in various signalling pathways. PP2A holoenzymes comprise a core dimer composed of a catalytic C and a structural A subunit, which can associate with a variable B-type subunit. The importance of the B-type subunits for PP2A regulation cannot be overestimated as they determine holoenzyme localisation, activity and substrate specificity. Three B-type subunit families have been identified: PR55/B, PR61/B' and PR72/B", of which the latter is currently the least characterised. Results We deduced the sequences and genomic organisation of the different murine PR72/B" isoforms: three genes encode nine isoforms, five of which are abundantly expressed and give rise to genuine PP2A subunits. Thereby, one novel subunit was identified. Using Northern blotting, we examined the tissue-specific and developmental expression of these subunits. All subunits are highly expressed in heart, suggesting an important cardiac function. Immunohistochemical analysis revealed a striated expression pattern of PR72 and PR130 in heart and skeletal muscle, but not in bladder smooth muscle. The subcellular localisation and cell cycle regulatory ability of several PR72/B" isoforms were determined, demonstrating differences as well as similarities. Conclusion In contrast to PR55/B and PR61/B', the PR72/B" family seems evolutionary more divergent, as only two of the murine genes have a human orthologue. We have integrated these results in a more consistent nomenclature of both human and murine PR72/B" genes and their transcripts/proteins. Our results provide a platform for the future generation of PR72/B" knockout mice. PMID:18715506

  15. In situ reaction mechanism studies on the Ti(NMe{sub 2}){sub 2}(O{sup i}Pr){sub 2}-D{sub 2}O and Ti(O{sup i}Pr){sub 3}[MeC(N{sup i}Pr){sub 2}]-D{sub 2}O atomic layer deposition processes

    SciTech Connect

    Tomczak, Yoann Knapas, Kjell; Leskelä, Markku; Ritala, Mikko

    2014-01-15

    Reaction mechanisms in the Ti(NMe{sub 2}){sub 2}(O{sup i}Pr){sub 2}-D{sub 2}O and Ti(O{sup i}Pr){sub 3}[MeC(N{sup i}Pr){sub 2}] [also written Ti(O{sup i}Pr){sub 3}(N{sup i}Pr-Me-amd)]-D{sub 2}O atomic layer deposition processes were studied in situ with quartz crystal microbalance (QCM) and quadrupole mass spectrometry (QMS) at 275 °C. For the Ti(NMe{sub 2}){sub 2}(O{sup i}Pr){sub 2}-D{sub 2}O process, both QCM and QMS results indicated adsorption of the Ti(NMe{sub 2}){sub 2}(O{sup i}Pr){sub 2} molecule through an exchange of at least one of its –NMe{sub 2} ligands with surface hydroxyl groups. Regarding the Ti(O{sup i}Pr){sub 3}(N{sup i}Pr-Me-amd)-D{sub 2}O process, a mismatch between the QCM and QMS results revealed more complex reactions: the decomposition of the [MeC(N{sup i}Pr){sub 2}] [also written (N{sup i}Pr-Me-amd)] ligand is suggested by the shape of the QCM data and the intensity of the QMS signals belonging to fragments of the [MeC(N{sup i}Pr){sub 2}] [also written (N{sup i}Pr-Me-amd)] ligand. A simple calculation model associating the growth rate per cycle of a crystalline film and the surface area taken by the ligands remaining after saturation was also used to support the decomposition of the [MeC(N{sup i}Pr){sub 2}] [also written (N{sup i}Pr-Me-amd)] ligand. The observed high growth rate is incompatible with the whole [MeC(N{sup i}Pr){sub 2}] (also written [N{sup i}Pr-Me-amd)] ligand remaining on the surface.

  16. Ru substitution effect on the peak effect in superconducting PrOs4Sb12

    NASA Astrophysics Data System (ADS)

    Miyazaki, Ryoichi; Higashinaka, Ryuji; Aoki, Yuji; Sugawara, Hitoshi; Sato, Hideyuki

    2012-12-01

    Ac susceptibility (χac) measurements on Pr(Os1-xRux)4Sb12 single crystals for x = 0.05 and 0.1 were performed by mutual inductance method. A peak structure caused by anomalously enhanced flux pinning force, which is so-called the peak effect, appears in the H dependence of χac. The peak structure shifts to lower fields as T increases and disappears in T > 1 K in both samples, while in PrOs4Sb12 it is observable up to near Tc. This fact indicates that the Ru substitution suppresses the peak effect. We demonstrate that the observed T dependent behavior of the peak structure can be explained roughly by the synchronization model although there remains deviation from the model curve, suggesting some modification may be needed in the model to be applied to Pr(Os1-xRux)4Sb12.

  17. High Pressure Synthesis and properties of (Ca,Pr)Fe2As2

    NASA Astrophysics Data System (ADS)

    Drye, Tyler; Taufour, Valentin; Kaluarachchi, Udhara; Ran, Sheng; Canfield, Paul; Paglione, Johnpierre

    2014-03-01

    Despite impressively high superconducting transition temperatures approaching 50 K, superconductivity in rare earth-doped CaFe2As2 appears to only involve a small volume fraction as determined by shielding fraction. In addition, the amount of Pr that can be doped into the system via ambient pressure flux synthesis is limited to <15%, due to a width of formation limitation. We report a study using high-pressure flux growth to substitute higher levels of Pr approaching 40% concentration. The superconducting properties of the resultant crystals are presented, including chemical composition, resistivity, and magnetization measurements. The final result is a complete phase diagram for the Pr-doped CaFe2As2 system. Work supported by an ICAM Junior Scientist Travel Award and an AFOSR MURI grant.

  18. IgA cold agglutinins recognize Pr and Sa antigens expressed on glycophorins.

    PubMed

    Roelcke, D; Hack, H; Kreft, H; MacDonald, B; Pereira, A; Habibi, B

    1993-06-01

    Three cases of IgA kappa cold agglutinins (CAs) were studied. One had anti-Pr1 specificity, one had anti-Pra, and one had anti-Sa. The CAs recognize O-glycans of glycophorins. The findings supplement previous data on anti-Pr1 specificities of four IgA kappa CAs. Because all IgA kappa CAs described recognize O-glycans of glycophorins, a close association between the CA IgA isotype and specificities for O-glycans becomes apparent. It is unlikely, however, that the striking association reflects interrelations between IgA CA structure and specificity, because anti-Sa specificity and all anti-Pr subspecificities were originally defined with IgM CAs.

  19. The role of PR in the formation of psychological readiness for a rogue wave events.

    NASA Astrophysics Data System (ADS)

    Chaykovskaya, N.; Rodin, A.

    2012-04-01

    In recent years the study of psychological foundations of human behavior when dealing with rogue waves has received increasing attention. However, this problem is only in the interest of a narrow circle of specialists, while the task is to explain the rules of behavior when dealing with the phenomenon to anyone who can get into this situation. This problem can only be solved by media and PR-specialists working in this field. PR- specialists are required to convey to people the need of correct action stereotype for assault element, because, as it is known, a fact only becomes a fact when it is written about in a newspaper or is made a story about in a summary of radio or TV news. This publication is devoted to the developing of forms and methods of PR-specialists activity in this area.

  20. PR Domain-containing Protein 7 (PRDM7) Is a Histone 3 Lysine 4 Trimethyltransferase*

    PubMed Central

    Blazer, Levi L.; Lima-Fernandes, Evelyne; Gibson, Elisa; Eram, Mohammad S.; Loppnau, Peter; Arrowsmith, Cheryl H.; Schapira, Matthieu; Vedadi, Masoud

    2016-01-01

    PR domain-containing protein 7 (PRDM7) is a primate-specific histone methyltransferase that is the result of a recent gene duplication of PRDM9. The two proteins are highly homologous, especially in the catalytic PR/SET domain, where they differ by only three amino acid residues. Here we report that PRDM7 is an efficient methyltransferase that selectively catalyzes the trimethylation of H3 lysine 4 (H3K4) both in vitro and in cells. Through selective mutagenesis we have dissected the functional roles of each of the three divergent residues between the PR domains of PRDM7 and PRDM9. These studies indicate that after a single serine to tyrosine mutation at residue 357 (S357Y), PRDM7 regains the substrate specificities and catalytic activities similar to its evolutionary predecessor, including the ability to efficiently methylate H3K36. PMID:27129774

  1. The prejudiced personality, racism, and anti-Semitism: the PR scale forty years later.

    PubMed

    Dunbar, E

    1995-10-01

    The relationship of prejudiced personality traits with racism and anti-Semitism was examined with 150 Asian American and White university students. The Prejudice (PR) scale, composed of 32 items from the Minnesota Multiphasic Personality Inventory, was administered along with the McConahay racism scale and the Selznick and Steinberg Anti-Semitism scale. Results indicated that for Whites, the PR scale was significantly correlated with old-fashioned and modern racism and anti-Semitism, replicating Gough's 1951 study (Gough, 1951b) with the PR scale. However, no such relationship was observed for the Asian American group. This suggests that personality traits of prejudicial attitudes may be relatively stable for Whites but may not be related to outgroup bias for other racial or ethnic groups.

  2. Tunable Charge and Spin Order in PrNiO_{3} Thin Films and Superlattices.

    PubMed

    Hepting, M; Minola, M; Frano, A; Cristiani, G; Logvenov, G; Schierle, E; Wu, M; Bluschke, M; Weschke, E; Habermeier, H-U; Benckiser, E; Le Tacon, M; Keimer, B

    2014-11-28

    We use polarized Raman scattering to probe lattice vibrations and charge ordering in 12 nm thick, epitaxially strained PrNiO_{3} films, and in superlattices of PrNiO_{3} with the band insulator PrAlO_{3}. A carefully adjusted confocal geometry is used to eliminate the substrate contribution to the Raman spectra. In films and superlattices under tensile strain which undergo a metal-insulator transition upon cooling, the Raman spectra reveal phonon modes characteristic of charge ordering. These anomalous phonons do not appear in compressively strained films, which remain metallic at all temperatures. For superlattices under compressive strain, the Raman spectra show no evidence of anomalous phonons indicative of charge ordering, while complementary resonant x-ray scattering experiments reveal antiferromagnetic order associated with a modest increase in resistivity upon cooling. This confirms theoretical predictions of a spin density wave phase driven by spatial confinement of the conduction electrons. PMID:25494088

  3. Aborder les soins préventifs chez les aînés

    PubMed Central

    Tazkarji, Bachir; Lam, Robert; Lee, Shawn; Meiyappan, Soumia

    2016-01-01

    Résumé Objectif Guider les médecins de famille dans l’élaboration de plans de dépistage et de traitements préventifs à l’intention de leurs patients âgés. Sources de l’information Une recension a été effectuée dans la base de données MEDLINE pour trouver des lignes directrices canadiennes sur les soins de santé primaires et les personnes âgées; des lignes directrices, des méta-analyses, des guides de pratique clinique ou des révisions systématiques portant sur le dépistage de masse chez les 80 ans et plus et les aînés fragiles, se limitant à ceux publiés entre 2006 et juillet 2016; et des articles sur les services de santé préventifs à l’intention des aînés et présentant un intérêt pour la pratique familiale ou les médecins de famille, limités à ceux publiés en anglais entre 2012 et juillet 2016. Message principal L’estimation de l’espérance de vie n’est pas une science facile ou précise, mais la fragilité est un concept émergent susceptible d’être utile à cet égard. Le Groupe d’étude canadien sur les soins de santé préventifs propose des lignes directrices sur le dépistage du cancer, mais elles sont moins précises en ce qui concerne les patients de plus de 74 ans et il faut donc individualiser les plans de prise en charge. L’estimation des années de vie qui restent aide à orienter vos recommandations concernant les plans de dépistage et de traitements préventifs. Les risques augmentent souvent proportionnellement avec la fragilité et la comorbidité. D’autre part, les bienfaits diminuent souvent à mesure que l’espérance de vie raccourcit. Les plans de prise en charge préventive devraient tenir compte des points de vue du patient et être convenus d’un commun accord. Un moyen mnémonique pour se rappeler des principaux domaines de prévention en soins primaires – CCMF, abréviation pour cancer, cardiovasculaire, mauvais équilibre, chute et ostéoporose, fiche de vaccinations pr

  4. Study of Glass Forming Ability Parameters of Mg-Ni-Pr-BASED Metallic Glasses

    NASA Astrophysics Data System (ADS)

    Prajapati, Sonal R.; Patel, Ashmi T.; Pratap, Arun

    Knowledge of Glass forming Ability (GFA) of metallic glasses is of great importance as it gives an insight of a better Glass former. Number of GFA parameters like Gibb’s free energy difference ∆G, ∆S, ∆H, η, γ, γm, Q, Trg (=Tg/Tl) etc. are calculated and compared for Mg-Ni-Pr-based metallic glass forming alloys to predict which parameter describes the best GFA criterion. On the basis of these parameters the excellent glass forming composition is identified. Also the GFA parameters of Mg-Ni-Pr-based alloys are studied in air and argon atmosphere. Present work suggests that ∆G is the best GFA criterion and Mg-Ni-Pr-based metallic glassy alloys can be successfully fabricated in air due to its high oxidation resistance ability.

  5. Significant enhancement in thermoelectric properties of polycrystalline Pr-doped SrTiO{sub 3−δ} ceramics originating from nonuniform distribution of Pr dopants

    SciTech Connect

    Dehkordi, Arash Mehdizadeh; Bhattacharya, Sriparna; He, Jian; Alshareef, Husam N.; Tritt, Terry M.

    2014-05-12

    Recently, we have reported a significant enhancement (>70% at 500 °C) in the thermoelectric power factor (PF) of bulk polycrystalline Pr-doped SrTiO{sub 3} ceramics employing a novel synthesis strategy which led to the highest ever reported values of PF among doped polycrystalline SrTiO{sub 3}. It was found that the formation of Pr-rich grain boundary regions gives rise to an enhancement in carrier mobility. In this Letter, we investigate the electronic and thermal transport in Sr{sub 1−x}Pr{sub x}TiO{sub 3} ceramics in order to determine the optimum doping concentration and to evaluate the overall thermoelectric performance. Simultaneous enhancement in the thermoelectric power factor and reduction in thermal conductivity in these samples resulted in more than 30% improvement in the dimensionless thermoelectric figure of merit (ZT) for the whole temperature range over all previously reported maximum values. Maximum ZT value of 0.35 was obtained at 500 °C.

  6. The Promise and Peril of Pre-Exposure Prophylaxis (PrEP): Using Social Science to Inform PrEP Interventions among Female Sex Workers

    PubMed Central

    Syvertsen, Jennifer L.; Bazzi, Angela M. Robertson; Scheibe, Andrew; Adebajo, Sylvia; Strathdee, Steffanie A.; Wechsberg, Wendee M.

    2015-01-01

    Advances in biomedical interventions to prevent HIV offer great promise in reducing the number of new infections across sub-Saharan Africa, particularly among vulnerable populations such as female sex workers. Several recent trials testing pre-exposure prophylaxis (PrEP) have demonstrated efficacy, although others have been stopped early for futility. Given the importance and complexities of social and behavioural factors that influence biomedical approaches to prevention, we discuss several key areas of consideration moving forward, including trial participation, adherence strategies, social relationships, and the structural factors that shape PrEP interest, use, and potential effectiveness among female sex workers in sub-Saharan Africa. Our review highlights the importance of involving social scientists in clinical and community-based research on PrEP. We advocate for a shift away from a singular “re-medicalization” of the HIV epidemic to that of a “reintegration” of interdisciplinary approaches to prevention that could benefit female sex workers and other key populations at risk of acquiring HIV. PMID:26050379

  7. Reduced response of splenocytes after mitogen-stimulation in the prion protein (PrP) gene-deficient mouse: PrPLP/Doppel production and cerebral degeneration

    SciTech Connect

    Kim, Chi-Kyeong; Hirose, Yuko; Sakudo, Akikazu; Takeyama, Natsumi; Kang, Chung-Boo; Taniuchi, Yojiro; Matsumoto, Yoshitsugu; Itohara, Shigeyoshi; Sakaguchi, Suehiro; Onodera, Takashi . E-mail: aonoder@mail.ecc.u-tokyo.ac.jp

    2007-06-29

    Splenocytes of wild-type (Prnp {sup +/+}) and prion protein gene-deficient (Prnp {sup -/-}) mice were treated with various activation stimuli such as T cell mitogen concanavalin A (ConA), phorbol 12-myristate 13-acetate (PMA) + ionomycin (Io), or B cell mitogen lipopolysaccharide (LPS). Cellular prion protein (PrP{sup C}) expression was enhanced following ConA stimulation, but not PMA + Io or LPS in Prnp {sup +/+} splenocytes. Rikn Prnp {sup -/-} splenocytes elicited lower cell proliferations than Prnp {sup +/+} or Zrch I Prnp {sup -/-} splenocytes after LPS stimulation and showed sporadic nerve cells in the cerebral cortex and deeper structure. Around the degenerated nerve cells, mild vacuolation in the neuropil was observed. This neural alteration correlated well to the suppressed response of B cells in the spleen. The finding that discrete lesions within the central nervous systems induced marked modulation of immune function probably indicates the existence of a delicately balanced neural-endocrine network by PrP{sup C} and PrPLP/Doppel.

  8. Characterization of Pr:LuAG scintillating crystals for X-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Bertoni, R.; Bonesini, M.; Cervi, T.; Clemenza, M.; De Bari, A.; Falcone, A.; Mazza, R.; Menegolli, A.; Nastasi, M.; Rossella, M.

    2016-07-01

    The main features of the Pr doped Lu3Al5O12 (Pr:LuAG) scintillating crystals for X-ray spectroscopy applications have been studied using different radioactive sources and photo-detectors. Pr:LuAG is cheaper, compared to a Germanium detector, but with remarkable properties which make it useful for many applications, from fundamental physics measurements to the PET imaging for medical purposes: high density, elevate light yield, fast response, high energy resolution, no hygroscopicity. A sample of Pr:LuAG crystals with 14 mm×14 mm surface area and 13 mm thickness and a NaI crystal of the same surface and 26 mm thickness used as a reference have been characterized with several radioactive sources, emitting photons in the range 100-1000keV. Different light detectors were adopted for the Pr:LuAG studies, sensitive to its UV emission (peak at 310 nm): a 3 in. PMT (Hamamatsu R11065) and new arrays of Hamamatsu SiPM S13361, with siliconic resin as a window. Preliminary results are presented on the performance of the Pr:LuAG crystals, to be mounted in a 2 × 2 array to be tested in the 2015 run of the FAMU experiment at RIKEN-RAL muon facility. The goal is the detection of the X-rays (around 130 keV) emitted during the de-excitation processes of the muonic hydrogen after the excitation with an IR laser with wavelength set at the resonance of the hyperfine splitting, to measure the muonic atom proton radius with unprecedented precision.

  9. Structural effects of PrP polymorphisms on intra- and interspecies prion transmission

    PubMed Central

    Angers, Rachel; Christiansen, Jeffrey; Nalls, Amy V.; Kang, Hae-Eun; Hunter, Nora; Hoover, Edward; Mathiason, Candace K.; Sheetz, Michael; Telling, Glenn C.

    2014-01-01

    Understanding the molecular parameters governing prion propagation is crucial for controlling these lethal, proteinaceous, and infectious neurodegenerative diseases. To explore the effects of prion protein (PrP) sequence and structural variations on intra- and interspecies transmission, we integrated studies in deer, a species naturally susceptible to chronic wasting disease (CWD), a burgeoning, contagious epidemic of uncertain origin and zoonotic potential, with structural and transgenic (Tg) mouse modeling and cell-free prion amplification. CWD properties were faithfully maintained in deer following passage through Tg mice expressing cognate PrP, and the influences of naturally occurring PrP polymorphisms on CWD susceptibility were accurately reproduced in Tg mice or cell-free systems. Although Tg mice also recapitulated susceptibility of deer to sheep prions, polymorphisms that provided protection against CWD had distinct and varied influences. Whereas substitutions at residues 95 and 96 in the unstructured region affected CWD propagation, their protective effects were overridden during replication of sheep prions in Tg mice and, in the case of residue 96, deer. The inhibitory effects on sheep prions of glutamate at residue 226 in elk PrP, compared with glutamine in deer PrP, and the protective effects of the phenylalanine for serine substitution at the adjacent residue 225, coincided with structural rearrangements in the globular domain affecting interaction between α-helix 3 and the loop between β2 and α-helix 2. These structure–function analyses are consistent with previous structural investigations and confirm a role for plasticity of this tertiary structural epitope in the control of PrP conversion and strain propagation. PMID:25034251

  10. Interaction of NIMIN1 with NPR1 Modulates PR Gene Expression in Arabidopsis

    PubMed Central

    Weigel, Ralf R.; Pfitzner, Ursula M.; Gatz, Christiane

    2005-01-01

    The Arabidopsis thaliana NONEXPRESSER OF PR GENES1 (NPR1, also known as NIM1) protein is an essential positive regulator of salicylic acid (SA)-induced PATHOGENESIS-RELATED (PR) gene expression and systemic acquired resistance (SAR). PR gene activity is regulated at the level of redox-dependent nuclear transport of NPR1. NPR1 interacts with members of the TGA family of transcription factors that are known to bind to SA-responsive elements in the PR-1 promoter. In an attempt to identify proteins involved in SA-mediated signal transduction, we previously described the isolation of three novel genes encoding distinct albeit structurally related proteins designated NIMIN1 (for NIM1-INTERACTING1), NIMIN2, and NIMIN3 that interact with NPR1 in the yeast two-hybrid system. Here, we show that NIMIN1 and NPR1 can be copurified from plant extracts, providing biochemical evidence for their interaction. We provide functional evidence for this interaction by describing transgenic plants constitutively expressing high amounts of NIMIN1. These plants show reduced SA-mediated PR gene induction and a compromised SAR, thus mimicking the described phenotype conferred by npr1. Moreover, they showed reduced RESISTANCE gene–mediated protection. These effects were dependent on the ability of NIMIN1 to interact with NPR1. Mutant plants with a T-DNA insertion in NIMIN1 as well as transgenic plants with reduced NIMIN1 mRNA levels showed hyperactivation of PR-1 gene expression after SA treatment but no effect on the disease resistance phenotype. Our results strongly suggest that NIMIN1 negatively regulates distinct functions of NPR1, providing a mechanism to modulate specific features of SAR. PMID:15749762

  11. Molecular cloning and functional characterization of an antifungal PR-5 protein from Ocimum basilicum.

    PubMed

    Rather, Irshad Ahmad; Awasthi, Praveen; Mahajan, Vidushi; Bedi, Yashbir S; Vishwakarma, Ram A; Gandhi, Sumit G

    2015-03-01

    Pathogenesis-related (PR) proteins are involved in biotic and abiotic stress responses of plants and are grouped into 17 families (PR-1 to PR-17). PR-5 family includes proteins related to thaumatin and osmotin, with several members possessing antimicrobial properties. In this study, a PR-5 gene showing a high degree of homology with osmotin-like protein was isolated from sweet basil (Ocimum basilicum L.). A complete open reading frame consisting of 675 nucleotides, coding for a precursor protein, was obtained by PCR amplification. Based on sequence comparisons with tobacco osmotin and other osmotin-like proteins (OLPs), this protein was named ObOLP. The predicted mature protein is 225 amino acids in length and contains 16 cysteine residues that may potentially form eight disulfide bonds, a signature common to most PR-5 proteins. Among the various abiotic stress treatments tested, including high salt, mechanical wounding and exogenous phytohormone/elicitor treatments; methyl jasmonate (MeJA) and mechanical wounding significantly induced the expression of ObOLP gene. The coding sequence of ObOLP was cloned and expressed in a bacterial host resulting in a 25kDa recombinant-HIS tagged protein, displaying antifungal activity. The ObOLP protein sequence appears to contain an N-terminal signal peptide with signatures of secretory pathway. Further, our experimental data shows that ObOLP expression is regulated transcriptionally and in silico analysis suggests that it may be post-transcriptionally and post-translationally regulated through microRNAs and post-translational protein modifications, respectively. This study appears to be the first report of isolation and characterization of osmotin-like protein gene from O. basilicum.

  12. Potential Interventions to Support Adherence to HIV Preexposure Prophylaxis (PrEP): A Systematic Review

    PubMed Central

    Marcus, Julia L.; Buisker, Timothy; Horvath, Tara; Amico, K. Rivet; Fuchs, Jonathan D.; Buchbinder, Susan P.; Grant, Robert M.; Liu, Albert Y.

    2014-01-01

    Objectives Adherence is critical for maximizing the effectiveness of preexposure prophylaxis (PrEP) in preventing HIV infection. Strategies for promoting adherence to HIV treatment, and their potential application to PrEP adherence, have received considerable attention. However, adherence promotion strategies for prevention medications have not been well characterized and may be more applicable to PrEP. We aimed to identify adherence support interventions that have been effective in other prevention fields and could be applied in the HIV prevention context to support pill taking among PrEP users. Methods To identify adherence support interventions that could be evaluated and applied in the PrEP context, we conducted a systematic review across the following prevention fields: hypertension, latent tuberculosis infection, hyperlipidemia, oral contraceptives, osteoporosis, malaria prophylaxis, and post-exposure prophylaxis for HIV infection. We included randomized controlled trials that evaluated the efficacy of interventions to improve adherence to daily oral medications prescribed for primary prevention in healthy individuals or for secondary prevention in asymptomatic individuals. Results Our searches identified 585 studies, of which 48 studies met the eligibility criteria and were included in the review; nine evaluated multiple strategies, yielding 64 separately tested interventions. Interventions with the strongest evidence for improving adherence included complex, resource-intensive interventions, which combined multiple adherence support approaches, and low-cost, low-intensity interventions that provided education or telephone calls for adherence support. Conclusions Our review identified adherence interventions with strong evidence of efficacy across prevention fields and provides recommendations for evaluating these interventions in upcoming PrEP studies. PMID:24580813

  13. Molecular cloning and functional characterization of an antifungal PR-5 protein from Ocimum basilicum.

    PubMed

    Rather, Irshad Ahmad; Awasthi, Praveen; Mahajan, Vidushi; Bedi, Yashbir S; Vishwakarma, Ram A; Gandhi, Sumit G

    2015-03-01

    Pathogenesis-related (PR) proteins are involved in biotic and abiotic stress responses of plants and are grouped into 17 families (PR-1 to PR-17). PR-5 family includes proteins related to thaumatin and osmotin, with several members possessing antimicrobial properties. In this study, a PR-5 gene showing a high degree of homology with osmotin-like protein was isolated from sweet basil (Ocimum basilicum L.). A complete open reading frame consisting of 675 nucleotides, coding for a precursor protein, was obtained by PCR amplification. Based on sequence comparisons with tobacco osmotin and other osmotin-like proteins (OLPs), this protein was named ObOLP. The predicted mature protein is 225 amino acids in length and contains 16 cysteine residues that may potentially form eight disulfide bonds, a signature common to most PR-5 proteins. Among the various abiotic stress treatments tested, including high salt, mechanical wounding and exogenous phytohormone/elicitor treatments; methyl jasmonate (MeJA) and mechanical wounding significantly induced the expression of ObOLP gene. The coding sequence of ObOLP was cloned and expressed in a bacterial host resulting in a 25kDa recombinant-HIS tagged protein, displaying antifungal activity. The ObOLP protein sequence appears to contain an N-terminal signal peptide with signatures of secretory pathway. Further, our experimental data shows that ObOLP expression is regulated transcriptionally and in silico analysis suggests that it may be post-transcriptionally and post-translationally regulated through microRNAs and post-translational protein modifications, respectively. This study appears to be the first report of isolation and characterization of osmotin-like protein gene from O. basilicum. PMID:25550044

  14. Aquifer Protist Response and the Potential for TCE Bioremediation with Burkholderia cepacia G4 PR1.

    PubMed

    Snyder; Millward; Steffensen

    2000-08-01

    Bacterivorous protists have been recovered from pristine and contaminated aquifer environments, but the ecological role of these organisms in bioremediation strategies has not been well defined. Burkholderia cepacia G4 PR1 constitutively expresses a toluene ortho-monooxygenase (tom) due to a secondary transposition of a Tn5 transposable element in a trichloroethylene (TCE) degradative plasmid (TOM). Groundwater and sediment from a potential site for a TCE bioremediation field demonstration were used in laboratory microcosms to test the survival of this organism. In nonsterile aquifer sediment slurries, the bacterium was eliminated in a logrithmic decay concomitant with an increase in bacterivorous protists. A half-life for the organism calculated from extinction coefficients increased logarithmically with increasing inoculation density above 1 x 10(6) PR1 ml(-1). For inoculation densities below this level, the half-life of PR1 increased exponentially with decreasing inoculation density. The lowest half-lives corresponded to densities of bacteria that stimulate response of bacterivores. In a column system designed to incorporate aquifer flow, repeated addition of PR1 resulted in a buildup of bacterivore populations and reduced half-life of the bacterium. Addition of TCE and growth substrate in the eluent resulted in prolonged survival of PR1 and apparent mineralization of TCE. The results indicate significant but predictable losses due to native bacterivores would occur within and beyond a treatment zone where PR1 would be added to the aquifer, and mineralization of TCE in contaminated groundwater might be possible with repeated inoculation and addition of nutrients.

  15. Correlates of PrEP Indication in a Multi-Site Cohort of Young HIV-Uninfected Transgender Women.

    PubMed

    Kuhns, Lisa M; Reisner, Sari L; Mimiaga, Matthew J; Gayles, Travis; Shelendich, Michael; Garofalo, Robert

    2016-07-01

    Transgender women are at high risk of HIV infection, with younger transgender women (YTW) particularly vulnerable. Pre-Exposure Prophylaxis (PrEP) has shown efficacy in reducing HIV acquisition, but little is known about PrEP indication or initiation among YTW. Baseline data from 180 YTW age 18-29 years enrolled in Project LifeSkills, an on-going HIV prevention intervention for YTW, were analyzed to examine factors associated with PrEP indication. The sample (mean age = 23.4, SD = 3.2) was comprised largely of women of color (69 %) and of low socioeconomic status (71 % unemployed). Overall, 62 % met criteria for PrEP indication, but only 5 % reported ever taking PrEP. Factors associated with increased odds of PrEP indication were: PrEP interest (aOR 3.24; 95 % CI 1.44, 7.33), number of recent anal sex partners (aOR 1.23; 95 % CI 1.04, 1.46), and lower collective self-esteem scores (aOR 0.67; 95 % CI 0.47, 0.94). Despite high levels of PrEP indication, there remain low levels of PrEP awareness and uptake among YTW.

  16. Magnetic ordering and crystal field effects in quasi-caged structure compound PrFe2Al8

    NASA Astrophysics Data System (ADS)

    Nair, Harikrishnan S.; Ghosh, Sarit K.; Ramesh Kumar, K.; Strydom, André M.

    2016-04-01

    The compound PrFe2Al8 possesses a three-dimensional network structure resulting from the packing of Al polyhedra centered at the transition metal element Fe and the rare earth Pr. Along the c-axis, Fe and Pr form chains which are separated from each other by the Al-network. In this paper, the magnetism and crystalline electric field effects in PrFe2Al8 are investigated through the analysis of magnetization and specific heat data. A magnetic phase transition in the Pr lattice is identified at TNPr ≈ 4 K in dc magnetization and ac susceptibility data. At 2 K, the magnetization isotherm presents a ferromagnetic saturation, however, failing to reach full spin-only ferromagnetic moment of Pr3+. Metamagnetic step-like low-field features are present in the magnetization curve at 2 K which is shown to shift upon field-cooling the material. Arrott plots centered around TPrN display "S"-like features suggestive of an inhomogeneous magnetic state. The magnetic entropy, Sm, estimated from specific heat outputs a value of R ln(2) at TN2 suggesting a doublet state for Pr3+. The magnetic specific heat is modeled by using a 9-level Schottky equation pertinent to the Pr3+ ion with J=4. Given the crystalline electric field situation of Pr3+, the inference of a doublet state from specific heat and consequent long-range magnetic order is an unexpected result.

  17. Correlates of PrEP Indication in a Multi-Site Cohort of Young HIV-Uninfected Transgender Women.

    PubMed

    Kuhns, Lisa M; Reisner, Sari L; Mimiaga, Matthew J; Gayles, Travis; Shelendich, Michael; Garofalo, Robert

    2016-07-01

    Transgender women are at high risk of HIV infection, with younger transgender women (YTW) particularly vulnerable. Pre-Exposure Prophylaxis (PrEP) has shown efficacy in reducing HIV acquisition, but little is known about PrEP indication or initiation among YTW. Baseline data from 180 YTW age 18-29 years enrolled in Project LifeSkills, an on-going HIV prevention intervention for YTW, were analyzed to examine factors associated with PrEP indication. The sample (mean age = 23.4, SD = 3.2) was comprised largely of women of color (69 %) and of low socioeconomic status (71 % unemployed). Overall, 62 % met criteria for PrEP indication, but only 5 % reported ever taking PrEP. Factors associated with increased odds of PrEP indication were: PrEP interest (aOR 3.24; 95 % CI 1.44, 7.33), number of recent anal sex partners (aOR 1.23; 95 % CI 1.04, 1.46), and lower collective self-esteem scores (aOR 0.67; 95 % CI 0.47, 0.94). Despite high levels of PrEP indication, there remain low levels of PrEP awareness and uptake among YTW. PMID:26336946

  18. PrEP implementation: moving from trials to policy and practice

    PubMed Central

    Cáceres, Carlos F; O'Reilly, Kevin R; Mayer, Kenneth H; Baggaley, Rachel

    2015-01-01

    Introduction It is increasingly clear that the HIV response will not be sustainable if the number of infections is not significantly reduced. Discussion For two decades, research has been ongoing to identify new behavioural and biomedical strategies to prevent HIV infection. In the past few years, the efficacy of several new strategies has been demonstrated, including oral pre-exposure prophylaxis (PrEP; i.e. daily use of tenofovir/emtricitabine). Because several social, political and logistic barriers remain, however, optimal PrEP implementation will require a better dissemination of new evidence in a number of areas and additional implementation research from various disciplinary perspectives (i.e. social science, policy and ethics; health systems; and economics, including cost-effectiveness studies). Discussion of new evidence on those topics, as well as case studies of potential PrEP implementation in diverse environments, can improve the understanding of the role that PrEP may play in addressing the global HIV/AIDS epidemic. In light of these needs, the Network for Multidisciplinary Studies in ARV-based HIV Prevention (NEMUS) and the World Health Organization (WHO) were honoured to co-organize a special issue of JIAS aimed at contributing to a scholarly discussion of current conditions surrounding PrEP implementation, potential impact and efficiency, social science concerns and the study of PrEP implementation in specific country cases. The papers included in this monograph identify and cover many of the main aspects of the complex yet promising discussions around PrEP implementation today. Conclusions This is a collection of timely contributions from global leaders in HIV research and policy that addresses geographic diversity, uses a trans-disciplinary approach and covers a variety of the complex issues raised by PrEP. As this publication will become accessible to all, we hope that it will remain a valuable resource for policy makers, programme managers

  19. Purification, characterization and preliminary crystallographic studies of a PR-10 protein from Pachyrrhizus erosus seeds.

    PubMed

    Wu, Fang; Li, Yikun; Chang, Shaojie; Zhou, Zhaocai; Wang, Fang; Song, Xiaomin; Lin, Yujuan; Gong, Weimin

    2002-12-01

    A 16 kDa protein SPE16 was purified from the seeds of Pachyrrhizus erosus. Its N-terminal amino-acid sequence showed significant sequence homology to pathogenesis-related proteins from the PR-10 family. An activity assay indicated that SPE16 possesses ribonuclease activity as do some other PR-10 proteins. SPE16 crystals were obtained by the hanging-drop vapour-diffusion method. The space group is P2(1)2(1)2(1), with unit-cell parameters a = 53.36, b = 63.70, c = 72.96 A. PMID:12454488

  20. The Puerto Rico Component of the National Tsunami Hazard and Mitigation Program Pr-Nthmp

    NASA Astrophysics Data System (ADS)

    Huerfano Moreno, V. A.; Hincapie-Cardenas, C. M.

    2014-12-01

    Tsunami hazard assessment, detection, warning, education and outreach efforts are intended to reduce losses to life and property. The Puerto Rico Seismic Network (PRSN) is participating in an effort with local and federal agencies, to developing tsunami hazard risk reduction strategies under the National Tsunami Hazards and Mitigation Program (NTHMP). This grant supports the TsunamiReady program which is the base of the tsunami preparedness and mitigation in PR. The Caribbean region has a documented history of damaging tsunamis that have affected coastal areas. The seismic water waves originating in the prominent fault systems around PR are considered to be a near-field hazard for Puerto Rico and the Virgin islands (PR/VI) because they can reach coastal areas within a few minutes after the earthquake. Sources for local, regional and tele tsunamis have been identified and modeled and tsunami evacuation maps were prepared for PR. These maps were generated in three phases: First, hypothetical tsunami scenarios on the basis of the parameters of potential underwater earthquakes were developed. Secondly, each of these scenarios was simulated. The third step was to determine the worst case scenario (MOM). The run-ups were drawn on GIS referenced maps and aerial photographs. These products are being used by emergency managers to educate the public and develop mitigation strategies. Online maps and related evacuation products are available to the public via the PR-TDST (PR Tsunami Decision Support Tool). Currently all the 44 coastal municipalities were recognized as TsunamiReady by the US NWS. The main goal of the program is to declare Puerto Rico as TsunamiReady, including two cities that are not coastal but could be affected by tsunamis. Based on these evacuation maps, tsunami signs were installed, vulnerability profiles were created, communication systems to receive and disseminate tsunami messages were installed in each TWFP, and tsunami response plans were approved

  1. PR notice 86-1. Notice to manufacturers, formulators, producers and registrants of pesticides

    SciTech Connect

    Not Available

    1986-02-01

    The document is one in the series of Pesticide Regulatory Notices, usually called PR Notices, which supplement the laws and regulations governing pesticide regulation in the US. These notices clarify, interpret and explain regulatory requirements and policies. They are directed at pesticide registrants and other parties interested in detailed procedures of regulation. Under Section 408 of the Federal Food, Drug, and Cosmetic Act (FFDCA), fees may be charged to cover the cost of processing tolerance petitions. The purpose of this PR Notice is to announce new Agency procedures regarding the submission of fees associated with tolerance petitions.

  2. PR notice 86-2. Notice to manufacturers, formulators, producers and registrants of pesticides

    SciTech Connect

    Not Available

    1986-03-01

    The document is one in the series of Pesticide Regulatory Notices, usually called PR Notices, which supplement the laws and regulations governing pesticide regulation in the US. These notices clarify, interpret and explain regulatory requirements and policies. They are directed at pesticide registrants and other parties interested in detailed procedures of regulation. The purpose of this PR Notice is to draw attention to and summarize the requirements to maintain records imposed under section 8 of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), sections 408 and 409 of the Federal Food, Drug, and Cosmetic Act (FFDCA), and regulations thereunder (40 C.F.R. 169.2 and 160.195).

  3. Pre-Activation Negativity (PrAN) in Brain Potentials to Unfolding Words

    PubMed Central

    Söderström, Pelle; Horne, Merle; Frid, Johan; Roll, Mikael

    2016-01-01

    We describe an event-related potential (ERP) effect termed the “pre-activation negativity” (PrAN), which is proposed to index the degree of pre-activation of upcoming word-internal morphemes in speech processing. Using lexical competition measures based on word-initial speech fragments (WIFs), as well as statistical analyses of ERP data from three experiments, it is shown that the PrAN is sensitive to lexical competition and that it reflects the degree of predictive certainty: the negativity is larger when there are fewer upcoming lexical competitors. PMID:27777558

  4. Radiochemical separations by the ring-oven technique-IV The system (144)Ce/(144)Pr.

    PubMed

    Klockow, D; Böhmer, R G

    1969-08-01

    By using filter papers impregnated with a manganese oxide hydrate having an average oxidation number of + 3, it is possible to separate (144)Pr from (144)Ce rapidly by the ring-oven technique. With 0.06-0.07M trichloracetic acid as wash-solution, the daughter nuclide can be concentrated in the ring zone with 80-90% yield and decontamination factors > 10(3). The half-life of the separated (144)Pr was found to be 17.60 +/- 0.05 min. The behaviour of other fission nuclides under the same conditions was also investigated. PMID:18960624

  5. Specific heat of new perovskite-type cobaltates Pr1-xNdxCoO3

    NASA Astrophysics Data System (ADS)

    Thakur, Rasna; Srivastava, Archana; Thakur, Rajesh K.; Gaur, N. K.

    2016-05-01

    Specific heat and Bulk modulus (B) of new perovskite-type cobaltates Pr1-xNdxCoO3 has been studied by means of a Modified Rigid Ion Model (MRIM) and Atoms in Molecules (AIM) theory in a wide temperature range (1K ≤ T ≤1000K). The effect of Nd doping on the elastic, cohesive and thermal properties of PrCoO3 have been studied probably for the first time by an atomistic approach. The computed results are in good agreement with the available experimental data.

  6. On the anisotropy energies for YCo 5 and PrCo 5 compounds

    NASA Astrophysics Data System (ADS)

    Kurihara, K.; Ohtsuka, S.; Ukai, T.; Mori, N.

    1985-05-01

    The approximate d bands for YCo 5 and PrCo 5 compounds are formulated by Deegan's prescription. The experimental result for the anisotropy energy of YCo 5 compound is analyzed by a d band model. The anisotropy energy for PrCo 5 compound is also analyzed in the same way as that for the YCo 5 compound, and the contributions due to 4f electrons are deduced. This contribution can be interpreted by the crystalline field theory with the use of a moderate crystalline field potential.

  7. The Puerto Rico Component of the National Tsunami Hazard and Mitigation Program (PR-NTHMP)

    NASA Astrophysics Data System (ADS)

    Vanacore, E. A.; Huerfano Moreno, V. A.; Lopez, A. M.

    2015-12-01

    The Caribbean region has a documented history of damaging tsunamis that have affected coastal areas. Of particular interest is the Puerto Rico - Virgin Islands (PRVI) region, where the proximity of the coast to prominent tectonic faults would result in near-field tsunamis. Tsunami hazard assessment, detection capabilities, warning, education and outreach efforts are common tools intended to reduce loss of life and property. It is for these reasons that the PRSN is participating in an effort with local and federal agencies to develop tsunami hazard risk reduction strategies under the NTHMP. This grant supports the TsunamiReady program, which is the base of the tsunami preparedness and mitigation in PR. In order to recognize threatened communities in PR as TsunamiReady by the US NWS, the PR Component of the NTHMP have identified and modeled sources for local, regional and tele-tsunamis and the results of simulations have been used to develop tsunami response plans. The main goal of the PR-NTHMP is to strengthen resilient coastal communities that are prepared for tsunami hazards, and recognize PR as TsunamiReady. Evacuation maps were generated in three phases: First, hypothetical tsunami scenarios of potential underwater earthquakes were developed, and these scenarios were then modeled through during the second phase. The third phase consisted in determining the worst-case scenario based on the Maximum of Maximums (MOM). Inundation and evacuation zones were drawn on GIS referenced maps and aerial photographs. These products are being used by emergency managers to educate the public and develop mitigation strategies. Maps and related evacuation products, like evacuation times, can be accessed online via the PR Tsunami Decision Support Tool. Based on these evacuation maps, tsunami signs were installed, vulnerability profiles were created, communication systems to receive and disseminate tsunami messages were installed in each TWFP, and tsunami response plans were

  8. Ground state proton radioactivity from 121Pr: when was this exotic nuclear decay mode first discovered?

    PubMed

    Robinson, A P; Woods, P J; Seweryniak, D; Davids, C N; Carpenter, M P; Hecht, A A; Peterson, D; Sinha, S; Walters, W B; Zhu, S

    2005-07-15

    Ground-state proton radioactivity has been identified from 121Pr. A transition with a proton energy of E(p)=882(10) keV [Q(p)=900(10) keV] and half-life t(1/2)=10(+6)(-3) ms has been observed and is assigned to the decay of a highly prolate deformed 3/2(+) or 3/2(-) Nilsson state. The present result is found to be incompatible with a previously reported observation of ground-state proton radioactivity from 121Pr, which would have represented the discovery of this phenomenon.

  9. L’administration postnatale de corticoïdes pour traiter ou prévenir la maladie pulmonaire chronique chez les prématurés

    PubMed Central

    Jefferies, Ann L

    2012-01-01

    RÉSUMÉ Les corticoïdes sont administrés pendant la période postnatale pour prévenir et traiter la maladie pulmonaire chronique néonatale (MPC) (qu’on appelle aussi dysplasie bronchopulmonaire), une cause importante de mortalité et de morbidité chez les nourrissons prématurés. Puisque l’administration de dexaméthasone ou d’hydrocortisone pendant les sept premiers jours de vie s’associe à un plus grand risque d’infirmité motrice cérébrale, il n’est pas recommandé d’amorcer rapidement une corticothérapie pour prévenir la MPC pendant la période postnatale. Après sept jours de vie, il a été établi que la dexaméthasone réduit le taux de MPC à 36 semaines d’âge postmenstruel et a moins de répercussions sur les issues neurodéveloppementales. Aucun essai n’a évalué si les bienfaits des corticoïdes sont supérieurs à leurs effets indésirables chez les nourrissons à haut risque de MPC ou atteints d’une grave MPC. Il n’est pas recommandé d’administrer systématiquement de la dexaméthasone à tous les enfants sous respirateur, mais les cliniciens peuvent envisager un court traitement à l’aide de faibles doses de dexaméthasone à des nourrissons sélectionnés à haut risque de MPC ou atteints d’une grave MPC. Aucune donnée probante n’indique que l’hydrocortisone est une solution efficace ou sécuritaire pour remplacer la dexaméthasone, et peu de données probantes appuient l’utilisation systématique de corticoïdes en aérosol dans le cadre de la prévention ou du traitement. On peut envisager la corticothérapie en aérosol pour remplacer la dexaméthasone dans le traitement de nourrissons sélectionnés atteints d’une grave MPC. La présente révision remplace le document de principes publié conjointement avec l’American Academy of Pediatrics en 2002.

  10. Cloning and characterization of PR5 gene from Curcuma amada and Zingiber officinale in response to Ralstonia solanacearum infection.

    PubMed

    Prasath, D; El-Sharkawy, I; Sherif, S; Tiwary, K S; Jayasankar, S

    2011-10-01

    Ginger (Zingiber officinale Roscoe), is an important spice crop that is badly affected by Ralstonia solanacearum wilt. Ginger does not set seed and sexual recombination has never been reported. In spite of extensive search in its habitats, no resistance source to Ralstonia induced bacterial wilt, could be located in ginger. Curcuma amada Roxb. is a potential donor for bacterial wilt resistance to Z. officinale, if the exact mechanism of resistance is understood. Pathogenesis-related (PR)-5 proteins are a family of proteins that are induced by different phytopathogens in many plants and share significant sequence similarity with thaumatin. Two putative PR5 genes, CaPR5 and ZoPR5, were amplified from C. amada and ginger, which encode precursor proteins of 227 and 224 amino acid residues, respectively, and share high homology with a number of other PR5 genes. The secondary and three-dimensional structure comparison did not reveal any striking differences between these two proteins. The expression of Ca and ZoPR5s under R. solanacearum inoculation was analyzed at different time points using quantitative real-time PCR (qRT-PCR). Our results reveal that CaPR5 is readily induced by the bacterium in C. amada, while ZoPR5 induction was very weak and slow in ginger. These results suggest that the CaPR5 could play a role in the molecular defense response of C. amada to pathogen attack. This is the first report of the isolation of PR5 gene from the C. amada and Z. officinale. Promoter analysis indicates the presence of a silencing element binding factor in ZoPR5-promoter, but not in CaPR5. Prospective promoter elements, such as GT-1 box and TGTCA, implicated as being positive regulatory elements for expression of PR proteins, occur in the 5'-flanking sequences of the CaPR5. Transient GUS expression study confirms its action with a weaker GUS expression in ginger, indicating that the PR5 expression may be controlled in the promoter. PMID:21594675

  11. Willingness to Take PrEP and Potential for Risk Compensation Among Highly Sexually Active Gay and Bisexual Men.

    PubMed

    Grov, Christian; Whitfield, Thomas H F; Rendina, H Jonathon; Ventuneac, Ana; Parsons, Jeffrey T

    2015-12-01

    Once-daily Truvada (Emtricitabine/Tenofovir) as a method of pre-exposure prophylaxis (PrEP) is one of the most promising biomedical interventions to eliminate new HIV infections; however, uptake among gay, bisexual, and other men who have sex with men has been slow amidst growing concern in popular/social media that PrEP use will result in reduced condom use (i.e., risk compensation). We investigated demographic, behavioral, and psychosocial differences in willingness to use PrEP as well as the perceived impact of PrEP on participants' condom use in a sample of 206 highly sexually active HIV-negative gay and bisexual men. Nearly half (46.1 %) said they would be willing to take PrEP if it were provided at no cost. Although men willing to take PrEP (vs. others) reported similar numbers of recent casual male partners (<6 weeks), they had higher odds of recent receptive condomless anal sex (CAS)-i.e., those already at high risk of contracting HIV were more willing to take PrEP. Neither age, race/ethnicity, nor income were associated with willingness to take PrEP, suggesting equal acceptability among subpopulations that are experiencing disparities in HIV incidence. There was limited evidence to suggest men would risk compensate. Only 10 % of men who had not engaged in recent CAS felt that PrEP would result in them starting to have CAS. Men who had not tested for HIV recently were also significantly more likely than others to indicate willingness to take PrEP. Offering PrEP to men who test infrequently may serve to engage them more in routine HIV/STI testing and create a continued dialogue around sexual health between patient and provider in order to prevent HIV infection.

  12. When the science fails and the ethics works: 'Fail-safe' ethics in the FEM-PrEP study.

    PubMed

    Kingori, Patricia

    2015-12-01

    This paper will explore the concept of 'fail safe' ethics in the FEM PrEP trial, and the practice of research and ethics on the ground. FEM-PrEP examined the efficacy of PrEP in African women after promising outcomes in research conducted with MSM. This was a hugely optimistic time and FEM-PrEP was mobilised using rights-based ethical arguments that women should have access to PrEP. This paper will present data collected during an ethnographic study of frontline research workers involved in FEM-PrEP. During our discussions, 'fail-safe' ethics emerged as concept that encapsulated their confidence that their ethics could not fail. However, in 2011, FEM-PrEP was halted and deemed a failure. The women involved in the study were held responsible because contrary to researcher's expectations they were not taking the oral PrEP being researched. This examination of FEM-PrEP will show that ethical arguments are increasingly deployed to mobilise, maintain and in some cases stop trials in ways which, at times, are superseded or co-opted by other interests. While promoting the interests of women, rights-based approaches are argued to indirectly justify the continuation of individualised, biomedical interventions which have been problematic in other women-centred trials. In this examination of FEM-PrEP, the rights-based approach obscured: ethical concerns beyond access to PrEP; the complexities of power relationships between donor and host countries; the operations of the HIV industry in research-saturated areas and the cumulative effect of unfilled expectations in HIV research and how this has shaped ideas of research and ethics.

  13. A PR-4 gene identified from Malus domestica is involved in the defense responses against Botryosphaeria dothidea.

    PubMed

    Bai, Suhua; Dong, Chaohua; Li, Baohua; Dai, Hongyi

    2013-01-01

    Pathogenesis-related protein-4 (PR-4) family is a group of proteins with a Barwin domain in C-terminus and generally thought to be involved in plant defense responses. However, their detailed roles are poorly understood in defense of apple plant against pathogenic infection. In the present study, a new PR-4 gene (designated as MdPR-4) was identified from Malus domestica, and its roles in defense responses of apple were investigated. The open reading frame of MdPR-4 gene is of 447 bp encoding a protein of 148 amino acids with a Barwin domain in C-terminus and a signal peptide of 26 amino acids in N-terminus. Sequence and structural analysis indicated that MdPR-4 protein belongs to class II of PR-4 family. The high-level expression of MdPR-4 was observed in flowers and leaves as revealed by quantitative real time PCR. The temporal expression analysis demonstrated that MdPR-4 expression could be up-regulated by Botryosphaeria dothidea infection and salicylic acid (SA) or methyl jasmonate (MeJA) treatment, but suppressed by diethyldithiocarbamic acid (DIECA). In vitro assays, recombinant MdPR-4 protein exhibited ribonuclease activity specific for single strand RNA and significant inhibition to hyphal growth of three apple pathogenic fungi B. dothidea, Valsa ceratosperma and Glomerella cingulata. Moreover, the inhibition was reduced by the presence of 5'-ADP. Taken all together, the results indicate that MdPR-4 protein is involved in the defense responses of apple against pathogenic attack by directly inhibiting hyphal growth, and the inhibition is correlated with its ribonuclease activity, where as MdPR-4 expression is regulated by both SA and JA signaling pathway.

  14. Transmission Properties of Human PrP 102L Prions Challenge the Relevance of Mouse Models of GSS.

    PubMed

    Asante, Emmanuel A; Grimshaw, Andrew; Smidak, Michelle; Jakubcova, Tatiana; Tomlinson, Andrew; Jeelani, Asif; Hamdan, Shyma; Powell, Caroline; Joiner, Susan; Linehan, Jacqueline M; Brandner, Sebastian; Wadsworth, Jonathan D F; Collinge, John

    2015-07-01

    Inherited prion disease (IPD) is caused by autosomal-dominant pathogenic mutations in the human prion protein (PrP) gene (PRNP). A proline to leucine substitution at PrP residue 102 (P102L) is classically associated with Gerstmann-Sträussler-Scheinker (GSS) disease but shows marked clinical and neuropathological variability within kindreds that may be caused by variable propagation of distinct prion strains generated from either PrP 102L or wild type PrP. To-date the transmission properties of prions propagated in P102L patients remain ill-defined. Multiple mouse models of GSS have focused on mutating the corresponding residue of murine PrP (P101L), however murine PrP 101L, a novel PrP primary structure, may not have the repertoire of pathogenic prion conformations necessary to accurately model the human disease. Here we describe the transmission properties of prions generated in human PrP 102L expressing transgenic mice that were generated after primary challenge with ex vivo human GSS P102L or classical CJD prions. We show that distinct strains of prions were generated in these mice dependent upon source of the inoculum (either GSS P102L or CJD brain) and have designated these GSS-102L and CJD-102L prions, respectively. GSS-102L prions have transmission properties distinct from all prion strains seen in sporadic and acquired human prion disease. Significantly, GSS-102L prions appear incapable of transmitting disease to conventional mice expressing wild type mouse PrP, which contrasts strikingly with the reported transmission properties of prions generated in GSS P102L-challenged mice expressing mouse PrP 101L. We conclude that future transgenic modeling of IPDs should focus exclusively on expression of mutant human PrP, as other approaches may generate novel experimental prion strains that are unrelated to human disease.

  15. L-Arginine ethylester enhances in vitro amplification of PrP(Sc) in macaques with atypical L-type bovine spongiform encephalopathy and enables presymptomatic detection of PrP(Sc) in the bodily fluids.

    PubMed

    Murayama, Y; Ono, F; Shimozaki, N; Shibata, H

    2016-02-12

    Protease-resistant, misfolded isoforms (PrP(Sc)) of a normal cellular prion protein (PrP(C)) in the bodily fluids, including blood, urine, and saliva, are expected to be useful diagnostic markers of prion diseases, and nonhuman primate models are suited for performing valid diagnostic tests for human Creutzfeldt-Jakob disease (CJD). We developed an effective amplification method for PrP(Sc) derived from macaques infected with the atypical L-type bovine spongiform encephalopathy (L-BSE) prion by using mouse brain homogenate as a substrate in the presence of polyanions and L-arginine ethylester. This method was highly sensitive and detected PrP(Sc) in infected brain homogenate diluted up to 10(10) by sequential amplification. This method in combination with PrP(Sc) precipitation by sodium phosphotungstic acid is capable of amplifying very small amounts of PrP(Sc) contained in the cerebrospinal fluid (CSF), saliva, urine, and plasma of macaques that have been intracerebrally inoculated with the L-BSE prion. Furthermore, PrP(Sc) was detectable in the saliva or urine samples as well as CSF samples obtained at the preclinical phases of the disease. Thus, our novel method may be useful for furthering the understanding of bodily fluid leakage of PrP(Sc) in nonhuman primate models. PMID:26802462

  16. L-Arginine ethylester enhances in vitro amplification of PrP(Sc) in macaques with atypical L-type bovine spongiform encephalopathy and enables presymptomatic detection of PrP(Sc) in the bodily fluids.

    PubMed

    Murayama, Y; Ono, F; Shimozaki, N; Shibata, H

    2016-02-12

    Protease-resistant, misfolded isoforms (PrP(Sc)) of a normal cellular prion protein (PrP(C)) in the bodily fluids, including blood, urine, and saliva, are expected to be useful diagnostic markers of prion diseases, and nonhuman primate models are suited for performing valid diagnostic tests for human Creutzfeldt-Jakob disease (CJD). We developed an effective amplification method for PrP(Sc) derived from macaques infected with the atypical L-type bovine spongiform encephalopathy (L-BSE) prion by using mouse brain homogenate as a substrate in the presence of polyanions and L-arginine ethylester. This method was highly sensitive and detected PrP(Sc) in infected brain homogenate diluted up to 10(10) by sequential amplification. This method in combination with PrP(Sc) precipitation by sodium phosphotungstic acid is capable of amplifying very small amounts of PrP(Sc) contained in the cerebrospinal fluid (CSF), saliva, urine, and plasma of macaques that have been intracerebrally inoculated with the L-BSE prion. Furthermore, PrP(Sc) was detectable in the saliva or urine samples as well as CSF samples obtained at the preclinical phases of the disease. Thus, our novel method may be useful for furthering the understanding of bodily fluid leakage of PrP(Sc) in nonhuman primate models.

  17. Progesterone receptor (PR) polyproline domain (PPD) mediates inhibition of epidermal growth factor receptor (EGFR) signaling in non-small cell lung cancer cells.

    PubMed

    Kawprasertsri, Sornsawan; Pietras, Richard J; Marquez-Garban, Diana C; Boonyaratanakornkit, Viroj

    2016-05-01

    Recent evidence has suggested a possible role for progesterone receptor (PR) in the progression of non-small cell lung cancer (NSCLC). However, little is known concerning roles of PR in NSCLC. PR contains a polyproline domain (PPD), which directly binds to the SH3 domain of signaling molecules. Because PPD-SH3 interactions are essential for EGFR signaling, we hypothesized that the presence of PR-PPD interfered with EGFR-mediated signaling and cell proliferation. We examined the role of PR-PPD in cell proliferation and signaling by stably expressing PR-B, or PR-B with disrupting mutations in the PPD (PR-BΔSH3), from a tetracycline-regulated promoter in A549 NSCLC cells. PR-B dose-dependently inhibited cell growth in the absence of ligand, and progestin (R5020) treatment further suppressed the growth. Treatment with RU486 abolished PR-B- and R5020-mediated inhibition of cell proliferation. Expression of PR-BΔSH3 and treatment with R5020 or RU486 had no effect on cell proliferation. Furthermore, PR-B expression but not PR-BΔSH3 expression reduced EGF-induced A549 proliferation and activation of ERK1/2, in the absence of ligand. Taken together, our data demonstrated the significance of PR extranuclear signaling through PPD interactions in EGFR-mediated proliferation and signaling in NSCLC.

  18. PR-Index: Using the h-Index and PageRank for Determining True Impact.

    PubMed

    Gao, Chao; Wang, Zhen; Li, Xianghua; Zhang, Zili; Zeng, Wei

    2016-01-01

    Several technical indicators have been proposed to assess the impact of authors and institutions. Here, we combine the h-index and the PageRank algorithm to do away with some of the individual limitations of these two indices. Most importantly, we aim to take into account value differences between citations-evaluating the citation sources by defining the h-index using the PageRank score rather than with citations. The resulting PR-index is then constructed by evaluating source popularity as well as the source publication authority. Extensive tests on available collections data (i.e., Microsoft Academic Search and benchmarks on the SIGKDD innovation award) show that the PR-index provides a more balanced impact measure than many existing indices. Due to its simplicity and similarity to the popular h-index, the PR-index may thus become a welcome addition to the technical indices already in use. Moreover, growth dynamics prior to the SIGKDD innovation award indicate that the PR-index might have notable predictive power. PMID:27627767

  19. Association of the pr Peptides with Dengue Virus at Acidic pH Blocks Membrane Fusion

    SciTech Connect

    Yu, I.-M.; Holdaway, H.A.; Chipman, P.R.; Kuhn, R.J.; Rossmann, M.G.; Chen, J.; Purdue

    2010-07-27

    Flavivirus assembles into an inert particle that requires proteolytic activation by furin to enable transmission to other hosts. We previously showed that immature virus undergoes a conformational change at low pH that renders it accessible to furin (I. M. Yu, W. Zhang, H. A. Holdaway, L. Li, V. A. Kostyuchenko, P. R. Chipman, R. J. Kuhn, M. G. Rossmann, and J. Chen, Science 319:1834-1837, 2008). Here we show, using cryoelectron microscopy, that the structure of immature dengue virus at pH 6.0 is essentially the same before and after the cleavage of prM. The structure shows that after cleavage, the proteolytic product pr remains associated with the virion at acidic pH, and that furin cleavage by itself does not induce any major conformational changes. We also show by liposome cofloatation experiments that pr retention prevents membrane insertion, suggesting that pr is present on the virion in the trans-Golgi network to protect the progeny virus from fusion within the host cell.

  20. La planification préalable des soins pour les patients en pédiatrie

    PubMed Central

    2008-01-01

    RÉSUMÉ Les progrès médicaux et technologiques ont permis d’ac-croître les taux de survie et d’améliorer la qualité de vie des nourrissons, des enfants et des adolescents ayant des maladies chroniques mettant la vie en danger. La planifi-cation préalable des soins inclut le processus relié aux discussions sur les traitements essentiels au maintien de la survie et la détermination des objectifs des soins de longue durée. Les dispensateurs de soins pédiatriques ont l’obligation éthique d’assimiler cet aspect des soins médicaux. Le présent document de principes vise à aider les dispensateurs de soins à discuter de la planification préalable des soins des patients pédiatriques dans diverses situations. La planification préalable des soins exige des communications efficaces afin de clarifier les objectifs des soins et de s’entendre sur les traitements pertinents ou non pour réaliser ces objectifs, y compris les mesures de réanimation et les mesures palliatives.

  1. Draft Genome Sequence and Gene Annotation of the Uropathogenic Bacterium Proteus mirabilis Pr2921

    PubMed Central

    Giorello, F. M.; Romero, V.; Farias, J.; Scavone, P.; Umpiérrez, A.; Zunino, P.

    2016-01-01

    Here, we report the genome sequence of Proteus mirabilis Pr2921, a uropathogenic bacterium that can cause severe complicated urinary tract infections. After gene annotation, we identified two additional copies of ucaA, one of the most studied fimbrial protein genes, and other fimbriae related-proteins that are not present in P. mirabilis HI4320. PMID:27340058

  2. 78 FR 26246 - Special Local Regulation, 50 Aniversario Balneario de Boqueron, Bahia de Boqueron; Boqueron, PR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-06

    .... SUPPLEMENTARY INFORMATION: Table of Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice... Boqueron, PR during the 50 Aniversario Balneario de Boqueron, a high speed boat race. The event is scheduled to take place on Sunday, May 5, 2013. Approximately 40 high- speed power boats will...

  3. Socialization and the Acquisition of Professional Discourse: A Case Study in the PR Industry

    ERIC Educational Resources Information Center

    Bremner, Stephen

    2012-01-01

    This article tracks the socialization of a Chinese intern into a Hong Kong PR company and considers the factors that enabled her to move toward acquiring the discourse of the profession. Taking a case study approach, the research is based on a detailed daily journal written by the intern during her internship, and two interviews. Over the 3-month…

  4. Terapia hormonal para el cáncer de próstata Hoja informativa

    Cancer.gov

    Hoja informativa que describe la terapia hormonal y su función en el tratamiento del cáncer de próstata. Incluye información acerca de los tipos diferentes de terapia hormonal, cómo se usan y los efectos secundarios posibles.

  5. Stability properties of PrPSc from cattle with experimental transmissible spongiform encephalopathies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transmissible Spongiform Encephalopathies (TSEs), including scrapie in sheep, chronic wasting disease (CWD) in cervids, and bovine spongiform encephalopathy (BSE), are fatal diseases of the nervous system associated with accumulation of misfolded prion protein (PrPSc). Different strains of BSE exist...

  6. Instantánea del cáncer de próstata

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de próstata; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  7. Interactions between Escherichia coli RNA polymerase and lambda repressor. Mutations in PRM affect repression of PR.

    PubMed

    Hwang, J J; Gussin, G N

    1988-04-20

    The rightward operator, OR, of bacteriophage lambda is part of a complex regulatory region that includes PRM, the promoter for repressor synthesis by a prophage, the rightward early promoter PR, and three repressor-binding sites, OR1, OR2 and OR3. By binding to OR2, repressor blocks transcription from PR and simultaneously stimulates the formation of open complexes between RNA polymerase and PRM. In this letter, we describe a test of the hypothesis that the interaction between RNA polymerase bound at PRM and repressor bound at OR2 increases the apparent affinity of repressor for OR. One implication of this hypothesis is that the amount of repressor required for repression of PR should be inversely correlated with PRM promoter strength. This is indeed the case. The amount of repressor required for 50% repression of PR is decreased by prmup-1, an "up" mutation of PRM, and is increased by prm- mutations. An unexpected finding is that in addition to their effect on the apparent affinity of repressor for OR, mutations in the -35 region of PRM alter the shape of repressor-titration curves. We propose that these mutations alter the interaction between RNA polymerase bound at PRM and repressor bound at OR2 in such a way that cooperativity in the binding of repressor to OR1 and OR2 is also disrupted.

  8. Anomalous behavior of PrNi{sub 2}B{sub 2}C borocarbide

    SciTech Connect

    Narozhnyi, V.N.; Freudenberger, J.; Fuchs, G.; Nenkov, K.A.; Eckert, D.; Czopnik, A.; Mueller, K.H.

    1999-12-01

    Electrical resistivity {rho}(T), specific heat C{sub p}(T), magnetic susceptibility {chi}(T), and magnetization M(H) have been measured for polycrystalline PrNi{sub 2}B{sub 2}C. Maxima in C{sub p}(T) and {vert{underscore}bar}d{chi}(T)/dT{vert{underscore}bar} dependencies were found at T{sub N} {approx} 4.3 K connected with AFM ordering observed earlier by neutron diffraction. The Sommerfeld coefficient is at least 250 mJ/mol K{sup 2}. The values of T{sub N} for PrNi{sub 2}B{sub 2}C and {vert{underscore}bar}d{Tc}/dx{vert{underscore}bar} for Y{sub 1{minus}x}Pr{sub x}Ni{sub 2}B{sub 2}C were found to be much larger than estimated by the de Gennes scaling from the Gd-based borocarbides. These facts as well as anomalous decrease of {rho}(T) found below 20K are connected with moderate heavy fermion behavior of antiferromagnetic PrNi{sub 2}B{sub 2}C.

  9. Visible upconversion emission of Pr3+ doped gadolinium gallium garnet nanocrystals.

    PubMed

    Naccache, R; Vetrone, F; Boyer, J C; Capobianco, J A; Speghini, A; Bettinelli, M

    2004-11-01

    The luminescence properties of a Pr3+-doped gadolinium gallium garnet (GGG, Gd3Ga5O12) nanocrystalline host were investigated. Dominant blue/green emission was observed emanating from the 3P0 --> 3H4 transition after excitation using a wavelength of 457.9 nm. Continuous wave excitation into the 1D2 level of the Pr3+ ion at 606.9 nm transition produced blue upconversion luminescence spectra, ascribed to emission from the 3P1 --> 3H4 and 3P0 --> 3H4 transitions. The increase in the decay times of the observed transitions following excitation with 606.9 nm is indicative of the dominance of an energy transfer upconversion (ETU) mechanism relative to excited state absorption (ESA). Furthermore, blue, green and red upconversion emission was observed from the 3P0, 3P1 and 1D2 states following excitation into the 1G4 energy level with 980 nm. No change in the decay times of the emitting states was observed following excitation with a wavelength of 980 or 457.9 nm; hence, upconversion was determined to primarily occur through ESA. The luminescence properties of the nanocrystals are compared to a single crystal of GGG:Pr3+ (bulk) with an identical Pr3+ concentration (1%).

  10. PR notice 87-9. Notice to pesticide applicants, registrants and petitioners

    SciTech Connect

    Not Available

    1987-08-01

    The document is one in the series of Pesticide Regulatory Notices, usually called PR Notices, which supplement the laws and regulations governing pesticide regulation in the US. These notices clarify, interpret and explain regulatory requirements and policies. They are directed at pesticide registrants and other parties interested in detailed procedures of regulation.

  11. PR notice 87-8. Notice to manufacturers, formulators, distributors, and registrants of pesticides

    SciTech Connect

    Not Available

    1987-06-01

    The document is one in the series of 'Pesticide Regulatory Notices', usually called 'PR Notices', which supplement the laws and regulations governing pesticide regulation in the US. These notices clarify, interpret and explain regulatory requirements and policies. They are directed at pesticide registrants and other parties interested in detailed procedures of regulation.

  12. PR notice 87-10. Notice to pesticide applicants, registrants and petitioners

    SciTech Connect

    Not Available

    1987-10-01

    The document is one in the series of Pesticide Regulatory Notices, usually called PR Notices, which supplement the laws and regulations governing pesticide regulation in the US. These notices clarify, interpret and explain regulatory requirements and policies. They are directed at pesticide registrants and other parties interested in detailed procedures of regulation.

  13. Filaggrin mutations p.R501X and c.2282del4 in ichthyosis vulgaris.

    PubMed

    Gruber, Robert; Janecke, Andreas R; Fauth, Christine; Utermann, Gerd; Fritsch, Peter O; Schmuth, Matthias

    2007-02-01

    Ichthyosis vulgaris (IV) is the most common hereditary disorder of cornification in humans, characterized by generalized fine scaling of the skin, palmar hyperlinearity with or without keratosis pilaris and atopy. Recently, the molecular basis of IV was ascribed to loss-of-function mutations in the gene encoding filaggrin (FLG), namely p.R501X and c.2282del4. Homozygotes and compound heterozygotes were severely affected whereas heterozygotes showed mild disease or were asymptomatic, suggesting semidominant inheritance with incomplete penetrance in heterozygotes. We report the presence of FLG mutations in 15 out of 21 IV patients with a marked generalized scaling phenotype, including eight affected members of a four-generation family. In this group of patients not only homozygous and compound heterozygous, but also heterozygous patients for p.R501X and c.2282del4 display a pronounced phenotype, whereas in none of six individuals these two mutations were detectable despite decreased filaggrin expression on immunohistochemistry in two patients, indicating that other mutations in FLG and/or in other genes remain to be identified. In contrast, two additional p.R501X heterozygotes from the extended family are asymptomatic. In a control population from west-Austria a combined p.R501X and c.2282del4 carrier frequency of 6/110 (5.45%) was observed. We confirm that these FLG variants are common, but our results point to the existence of additional modifiers.

  14. Detection of PrPres in Genetically Susceptible Fetuses from Sheep with Natural Scrapie

    PubMed Central

    Garza, María Carmen; Fernández-Borges, Natalia; Bolea, Rosa; Badiola, Juan José; Castilla, Joaquín; Monleón, Eva

    2011-01-01

    Scrapie is a transmissible spongiform encephalopathy with a wide PrPres dissemination in many non-neural tissues and with high levels of transmissibility within susceptible populations. Mechanisms of transmission are incompletely understood. It is generally assumed that it is horizontally transmitted by direct contact between animals or indirectly through the environment, where scrapie can remain infectious for years. In contrast, in utero vertical transmission has never been demonstrated and has rarely been studied. Recently, the use of the protein misfolding cyclic amplification technique (PMCA) has allowed prion detection in various tissues and excretions in which PrPres levels have been undetectable by traditional assays. The main goal of this study was to detect PrPres in fetal tissues and the amniotic fluid from natural scrapie infected ewes using the PMCA technique. Six fetuses from three infected pregnant ewes in an advanced clinical stage of the disease were included in the study. From each fetus, amniotic fluid, brain, spleen, ileo-cecal valve and retropharyngeal lymph node samples were collected and analyzed using Western blotting and PMCA. Although all samples were negative using Western blotting, PrPres was detected after in vitro amplification. Our results represent the first time the biochemical detection of prions in fetal tissues, suggesting that the in utero transmission of scrapie in natural infected sheep might be possible. PMID:22194786

  15. Propagation of Information About Preexposure Prophylaxis (PrEP) for HIV Prevention Through Twitter.

    PubMed

    McLaughlin, Margaret L; Hou, Jinghui; Meng, Jingbo; Hu, Chih-Wei; An, Zheng; Park, Mina; Nam, Yujung

    2016-08-01

    Previous literature has suggested that examining Twitter messages can be productive for studying how the public shares and spreads health information on social media. Preexposure prophylaxis (PrEP) is a promising approach to HIV prevention, yet there are many issues that may influence its effective implementation. This study examined social representations of PrEP on Twitter. One thousand four hundred and thirty-five Tweets were collected and 774 English Tweets were content-analyzed to explore propagation of various issues around daily oral PrEP, as well as characteristics of the sources of those Tweets. We also examined how Twitter message content influenced information propagation. Our findings revealed that PrEP-related information on Twitter covered a wide range of issues, and individual users constituted the majority of the Tweet creators among all the sources, including news media, nonprofit and academic groups, and commercial entities. Using Poisson regression, we also found that a Tweet's affective tone was a significant predictor of message propagation frequency. Implications for health practitioners are discussed.

  16. Recognising Workplace Learning: The Emerging Practices of e-RPL and e-PR

    ERIC Educational Resources Information Center

    Cameron, Roslyn

    2012-01-01

    Purpose: The use of e-portfolios in recognition of prior learning (RPL) processes in workplace and professional practice contexts has attracted little attention in the literature due to its emergent nature. This study seeks to explore the growing incidence of e-portfolio-based RPL (e-RPL) and professional recognition (e-PR) processes in Australia…

  17. Biosynthesis of 130-kilodalton mosquito larvicide in the cyanobacterium Agmenellum quadruplicatum PR-6.

    PubMed

    Angsuthanasombat, C; Panyim, S

    1989-09-01

    The 130-kilodalton mosquito larvicidal gene, cloned from Bacillus thuringiensis var. israelensis, was introduced into the cyanobacterium Agmenellum quadruplicatum PR-6 by plasmid transformation. Transformed cells synthesized 130-kilodalton delta-endotoxin protein and showed mosquito larvicidal activity. Results demonstrate a potential use of a cyanobacterium for biological control of mosquitoes.

  18. Multiple drug resistant mechanisms against darunavir, amprenavir, and nelfinavir of HIV-1 PR

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoqing; Dai, Qi; Xiu, Zhilong

    2013-02-01

    Acquired immune deficiency syndrome (AIDS) is a disease of the human immune system caused by the human immunodeficiency virus (HIV), which is infecting more humans and is expanding faster in the world. The illness interferes with the immune system, making people with AIDS much more likely to get infections, including opportunistic infections and tumors that do not affect people with working immune systems. HIV-1 PR is one of the major targets of anti-AIDS drug discovery. It is, therefore, necessary to develop some inhibitors against HIV-1 PR. In this work, we executed molecular dynamics (MDs) simulation of HIV-1 PR with drugs darunavir (DRV), amprenavir (APV), nelfinavir (NFV), and examined the resistant mechanism of L10I, G48V, I54V, and L90M mutations of this PR, aiming at designing promising drugs. The comparative analysis suggests that the existences of dodecahydroisoquinoline ring at P1' subsite, 4-aminophenylsulfonamide at P2' subsite, and bis-tetrahydrofuranylurethane at P2 subsite are helpful for maintaining the high affinity of the inhibitor for the protease and exhibiting high potency against multiple drug resistance (MDR) mutant protease.

  19. Magneto-Optical Response of Electron Doped Cuprates Pr2-xCexCuO4

    NASA Astrophysics Data System (ADS)

    Margankunte, Naveen; Zimmers, Alexandra; Tanner, D. B.; Greene, R. L.; Wang, Y. J.

    2006-09-01

    We report mid-infrared transmission measurements of electron doped Pr2-xCexCuO4 (PCCO) thin films for a wide range of dopings, in the large energy pseudogap regime both as a function of temperature and magnetic field. While the temperature dependent measurements show clear signatures of pseudogap, there is no magnetic field induced effect.

  20. 75 FR 63402 - FM Table of Allotments, Culebra, PR, Charlotte Amalie, and Christiansted, VI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-15

    ... COMMISSION 47 CFR Part 73 FM Table of Allotments, Culebra, PR, Charlotte Amalie, and Christiansted, VI AGENCY... 237B for vacant Channel 271B at Charlotte Amalie, Virgin Islands to enable Station WNVE-FM to obtain an... license of FM Station WJKC to reflect this change. The ultimate permittee of Channel 237B at...