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Sample records for high cdk1 activity

  1. Waves of Cdk1 Activity in S Phase Synchronize the Cell Cycle in Drosophila Embryos.

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    Deneke, Victoria E; Melbinger, Anna; Vergassola, Massimo; Di Talia, Stefano

    2016-08-22

    Embryos of most metazoans undergo rapid and synchronous cell cycles following fertilization. While diffusion is too slow for synchronization of mitosis across large spatial scales, waves of Cdk1 activity represent a possible process of synchronization. However, the mechanisms regulating Cdk1 waves during embryonic development remain poorly understood. Using biosensors of Cdk1 and Chk1 activities, we dissect the regulation of Cdk1 waves in the Drosophila syncytial blastoderm. We show that Cdk1 waves are not controlled by the mitotic switch but by a double-negative feedback between Cdk1 and Chk1. Using mathematical modeling and surgical ligations, we demonstrate a fundamental distinction between S phase Cdk1 waves, which propagate as active trigger waves in an excitable medium, and mitotic Cdk1 waves, which propagate as passive phase waves. Our findings show that in Drosophila embryos, Cdk1 positive feedback serves primarily to ensure the rapid onset of mitosis, while wave propagation is regulated by S phase events. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Cdk1 plays matchmaker for the Polo-like kinase and its activator SPAT-1/Bora.

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    Tavernier, Nicolas; Panbianco, Costanza; Gotta, Monica; Pintard, Lionel

    2015-08-03

    Mitosis is orchestrated by several protein kinases including Cdks, Plks and Aurora kinases. Despite considerable progress toward understanding the individual function of these protein kinases, how their activity is coordinated in space and time during mitosis is less well understood. In a recent article published in the Journal of Cell Biology, we show that CDK-1 regulates PLK-1 activity during mitosis in C. elegans embryos through multisite phosphorylation of the PLK-1 activator SPAT-1 (Aurora Borealis, Bora in human). SPAT-1 variants mutated on CDK-1 phosphorylation sites results in severe delays in mitotic entry, mimicking embryos lacking spat-1 or plk-1 function. We further show that SPAT-1 phosphorylation by CDK-1 promotes its binding to PLK-1 and stimulates PLK-1 phosphorylation on its activator T-loop by Aurora A kinase in vitro. Likewise, we find that phosphorylation of Bora by Cdk1 promotes phosphorylation of human Plk1 by Aurora A suggesting that this mechanism is conserved in humans. These results indicate that Cdk1 regulates Plk1 by boosting its kinase activity. Here we discuss these recent findings and open questions regarding the regulation of Plk1/PLK-1 by Cdk1/CDK-1 and Bora/SPAT-1.

  3. Mastl is required for timely activation of APC/C in meiosis I and Cdk1 reactivation in meiosis II.

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    Adhikari, Deepak; Diril, M Kasim; Busayavalasa, Kiran; Risal, Sanjiv; Nakagawa, Shoma; Lindkvist, Rebecca; Shen, Yan; Coppola, Vincenzo; Tessarollo, Lino; Kudo, Nobuaki R; Kaldis, Philipp; Liu, Kui

    2014-09-29

    In mitosis, the Greatwall kinase (called microtubule-associated serine/threonine kinase like [Mastl] in mammals) is essential for prometaphase entry or progression by suppressing protein phosphatase 2A (PP2A) activity. PP2A suppression in turn leads to high levels of Cdk1 substrate phosphorylation. We have used a mouse model with an oocyte-specific deletion of Mastl to show that Mastl-null oocytes resume meiosis I and reach metaphase I normally but that the onset and completion of anaphase I are delayed. Moreover, after the completion of meiosis I, Mastl-null oocytes failed to enter meiosis II (MII) because they reassembled a nuclear structure containing decondensed chromatin. Our results show that Mastl is required for the timely activation of anaphase-promoting complex/cyclosome to allow meiosis I exit and for the rapid rise of Cdk1 activity that is needed for the entry into MII in mouse oocytes.

  4. Human Cdc14B promotes progression through mitosis by dephosphorylating Cdc25 and regulating Cdk1/cyclin B activity.

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    Indra Tumurbaatar

    Full Text Available Entry into and progression through mitosis depends on phosphorylation and dephosphorylation of key substrates. In yeast, the nucleolar phosphatase Cdc14 is pivotal for exit from mitosis counteracting Cdk1-dependent phosphorylations. Whether hCdc14B, the human homolog of yeast Cdc14, plays a similar function in mitosis is not yet known. Here we show that hCdc14B serves a critical role in regulating progression through mitosis, which is distinct from hCdc14A. Unscheduled overexpression of hCdc14B delays activation of two master regulators of mitosis, Cdc25 and Cdk1, and slows down entry into mitosis. Depletion of hCdc14B by RNAi prevents timely inactivation of Cdk1/cyclin B and dephosphorylation of Cdc25, leading to severe mitotic defects, such as delay of metaphase/anaphase transition, lagging chromosomes, multipolar spindles and binucleation. The results demonstrate that hCdc14B-dependent modulation of Cdc25 phosphatase and Cdk1/cyclin B activity is tightly linked to correct chromosome segregation and bipolar spindle formation, processes that are required for proper progression through mitosis and maintenance of genomic stability.

  5. Phosphorylation of SAMHD1 by Cyclin A2/CDK1 Regulates Its Restriction Activity toward HIV-1

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    Alexandra Cribier

    2013-04-01

    Full Text Available SAMHD1 restricts HIV-1 replication in myeloid and quiescent CD4+ T cells. Here, we show that SAMHD1 restriction activity is regulated by phosphorylation. SAMHD1 interacts with cyclin A2/cdk1 only in cycling cells. Cyclin A2/CDK1 phosphorylates SAMHD1 at the Threonine 592 residue both in vitro and in vivo. Phosphorylation of SAMHD1 Thr592 correlates with loss of its ability to restrict HIV-1. Indeed, while PMA treatment of proliferating THP1 cells results in reduced Thr592 phosphorylation, activation of resting peripheral blood mononuclear cells (PBMCs and purified quiescent CD4+ T cells results in increased phosphorylation of SAMHD1 Thr592. Interestingly, we found that treatment of cells by type 1 interferon reduced Thr592 phosphorylation, reinforcing the link between the phosphorylation of SAMHD1 and its antiviral activity. Unlike wild-type SAMHD1, a phosphorylation-defective mutant was able to restrict HIV-1 replication in both PMA-treated and untreated cells. Our results uncover the phosphorylation of SAMHD1 at Thr592 by cyclin A2/CDK1 as a key regulatory mechanism of its antiviral activity.

  6. CDK1-Cyclin B1 Activates RNMT, Coordinating mRNA Cap Methylation with G1 Phase Transcription.

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    Aregger, Michael; Kaskar, Aneesa; Varshney, Dhaval; Fernandez-Sanchez, Maria Elena; Inesta-Vaquera, Francisco A; Weidlich, Simone; Cowling, Victoria H

    2016-03-03

    The creation of translation-competent mRNA is dependent on RNA polymerase II transcripts being modified by addition of the 7-methylguanosine (m7G) cap. The factors that mediate splicing, nuclear export, and translation initiation are recruited to the transcript via the cap. The cap structure is formed by several activities and completed by RNMT (RNA guanine-7 methyltransferase), which catalyzes N7 methylation of the cap guanosine. We report that CDK1-cyclin B1 phosphorylates the RNMT regulatory domain on T77 during G2/M phase of the cell cycle. RNMT T77 phosphorylation activates the enzyme both directly and indirectly by inhibiting interaction with KPNA2, an RNMT inhibitor. RNMT T77 phosphorylation results in elevated m7G cap methyltransferase activity at the beginning of G1 phase, coordinating mRNA capping with the burst of transcription that occurs following nuclear envelope reformation. RNMT T77 phosphorylation is required for the production of cohort of proteins, and inhibiting T77 phosphorylation reduces the cell proliferation rate. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Cdk1 Phosphorylates SPAT-1/Bora to Promote Plk1 Activation in C. elegans and Human Cells

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    Yann Thomas

    2016-04-01

    Full Text Available The conserved Bora protein is a Plk1 activator, essential for checkpoint recovery after DNA damage in human cells. Here, we show that Bora interacts with Cyclin B and is phosphorylated by Cyclin B/Cdk1 at several sites. The first 225 amino acids of Bora, which contain two Cyclin binding sites and three conserved phosphorylated residues, are sufficient to promote Plk1 phosphorylation by Aurora A in vitro. Mutating the Cyclin binding sites or the three conserved phosphorylation sites abrogates the ability of the N terminus of Bora to promote Plk1 activation. In human cells, Bora-carrying mutations of the three conserved phosphorylation sites cannot sustain mitotic entry after DNA damage. In C. elegans embryos, mutation of the three conserved phosphorylation sites in SPAT-1, the Bora ortholog, results in a severe mitotic entry delay. Our results reveal a crucial and conserved role of phosphorylation of the N terminus of Bora for Plk1 activation and mitotic entry.

  8. Pin1-mediated Sp1 phosphorylation by CDK1 increases Sp1 stability and decreases its DNA-binding activity during mitosis.

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    Yang, Hang-Che; Chuang, Jian-Ying; Jeng, Wen-Yih; Liu, Chia-I; Wang, Andrew H-J; Lu, Pei-Jung; Chang, Wen-Chang; Hung, Jan-Jong

    2014-12-16

    We have shown that Sp1 phosphorylation at Thr739 decreases its DNA-binding activity. In this study, we found that phosphorylation of Sp1 at Thr739 alone is necessary, but not sufficient for the inhibition of its DNA-binding activity during mitosis. We demonstrated that Pin1 could be recruited to the Thr739(p)-Pro motif of Sp1 to modulate the interaction between phospho-Sp1 and CDK1, thereby facilitating CDK1-mediated phosphorylation of Sp1 at Ser720, Thr723 and Thr737 during mitosis. Loss of the C-terminal end of Sp1 (amino acids 741-785) significantly increased Sp1 phosphorylation, implying that the C-terminus inhibits CDK1-mediated Sp1 phosphorylation. Binding analysis of Sp1 peptides to Pin1 by isothermal titration calorimetry indicated that Pin1 interacts with Thr739(p)-Sp1 peptide but not with Thr739-Sp1 peptide. X-ray crystallography data showed that the Thr739(p)-Sp1 peptide occupies the active site of Pin1. Increased Sp1 phosphorylation by CDK1 during mitosis not only stabilized Sp1 levels by decreasing interaction with ubiquitin E3-ligase RNF4 but also caused Sp1 to move out of the chromosomes completely by decreasing its DNA-binding activity, thereby facilitating cell cycle progression. Thus, Pin1-mediated conformational changes in the C-terminal region of Sp1 are critical for increased CDK1-mediated Sp1 phosphorylation to facilitate cell cycle progression during mitosis.

  9. Dual control by Cdk1 phosphorylation of the budding yeast APC/C ubiquitin ligase activator Cdh1.

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    Höckner, Sebastian; Neumann-Arnold, Lea; Seufert, Wolfgang

    2016-07-15

    The antagonism between cyclin-dependent kinases (Cdks) and the ubiquitin ligase APC/C-Cdh1 is central to eukaryotic cell cycle control. APC/C-Cdh1 targets cyclin B and other regulatory proteins for degradation, whereas Cdks disable APC/C-Cdh1 through phosphorylation of the Cdh1 activator protein at multiple sites. Budding yeast Cdh1 carries nine Cdk phosphorylation sites in its N-terminal regulatory domain, most or all of which contribute to inhibition. However, the precise role of individual sites has remained unclear. Here, we report that the Cdk phosphorylation sites of yeast Cdh1 are organized into autonomous subgroups and act through separate mechanisms. Cdk sites 1-3 had no direct effect on the APC/C binding of Cdh1 but inactivated a bipartite nuclear localization sequence (NLS) and thereby controlled the partitioning of Cdh1 between cytoplasm and nucleus. In contrast, Cdk sites 4-9 did not influence the cell cycle-regulated localization of Cdh1 but prevented its binding to the APC/C. Cdk sites 4-9 reside near two recently identified APC/C interaction motifs in a pattern conserved with the human Cdh1 orthologue. Thus a Cdk-inhibited NLS goes along with Cdk-inhibited APC/C binding sites in yeast Cdh1 to relay the negative control by Cdk1 phosphorylation of the ubiquitin ligase APC/C-Cdh1.

  10. Cdc25 Phosphatases Are Required for Timely Assembly of CDK1-Cyclin B at the G2/M Transition*

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    Timofeev, Oleg; Cizmecioglu, Onur; Settele, Florian; Kempf, Tore; Hoffmann, Ingrid

    2010-01-01

    Progression through mitosis requires the coordinated regulation of Cdk1 kinase activity. Activation of Cdk1 is a multistep process comprising binding of Cdk1 to cyclin B, relocation of cyclin-kinase complexes to the nucleus, activating phosphorylation of Cdk1 on Thr161 by the Cdk-activating kinase (CAK; Cdk7 in metazoans), and removal of inhibitory Thr14 and Tyr15 phosphorylations. This dephosphorylation is catalyzed by the dual specific Cdc25 phosphatases, which occur in three isoforms in mammalian cells, Cdc25A, -B, and -C. We find that expression of Cdc25A leads to an accelerated G2/M phase transition. In Cdc25A-overexpressing cells, Cdk1 exhibits high kinase activity despite being phosphorylated on Tyr15. In addition, Tyr15-phosphorylated Cdk1 binds more cyclin B in Cdc25A-overexpressing cells compared with control cells. Consistent with this observation, we demonstrate that in human transformed cells, Cdc25A and Cdc25B, but not Cdc25C phosphatases have an effect on timing and efficiency of cyclin-kinase complex formation. Overexpression of Cdc25A or Cdc25B promotes earlier assembly and activation of Cdk1-cyclin B complexes, whereas repression of these phosphatases by short hairpin RNA has a reverse effect, leading to a substantial decrease in amounts of cyclin B-bound Cdk1 in G2 and mitosis. Importantly, we find that Cdc25A overexpression leads to an activation of Cdk7 and increase in Thr161 phosphorylation of Cdk1. In conclusion, our data suggest that complex assembly and dephosphorylation of Cdk1 at G2/M is tightly coupled and regulated by Cdc25 phosphatases. PMID:20360007

  11. Fimbrin phosphorylation by metaphase Cdk1 regulates actin cable dynamics in budding yeast.

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    Miao, Yansong; Han, Xuemei; Zheng, Liangzhen; Xie, Ying; Mu, Yuguang; Yates, John R; Drubin, David G

    2016-01-01

    Actin cables, composed of actin filament bundles nucleated by formins, mediate intracellular transport for cell polarity establishment and maintenance. We previously observed that metaphase cells preferentially promote actin cable assembly through cyclin-dependent kinase 1 (Cdk1) activity. However, the relevant metaphase Cdk1 targets were not known. Here we show that the highly conserved actin filament crosslinking protein fimbrin is a critical Cdk1 target for actin cable assembly regulation in budding yeast. Fimbrin is specifically phosphorylated on threonine 103 by the metaphase cyclin-Cdk1 complex, in vivo and in vitro. On the basis of conformational simulations, we suggest that this phosphorylation stabilizes fimbrin's N-terminal domain, and modulates actin filament binding to regulate actin cable assembly and stability in cells. Overall, this work identifies fimbrin as a key target for cell cycle regulation of actin cable assembly in budding yeast, and suggests an underlying mechanism.

  12. Cdk1-dependent control of membrane-trafficking dynamics

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    McCusker, Derek; Royou, Anne; Velours, Christophe; Kellogg, Douglas

    2012-01-01

    Cyclin-dependent kinase 1 (Cdk1) is required for initiation and maintenance of polarized cell growth in budding yeast. Cdk1 activates Rho-family GTPases, which polarize the actin cytoskeleton for delivery of membrane to growth sites via the secretory pathway. Here we investigate whether Cdk1 plays additional roles in the initiation and maintenance of polarized cell growth. We find that inhibition of Cdk1 causes a cell surface growth defect that is as severe as that caused by actin depolymeriz...

  13. Proteomics reveals a switch in CDK1-associated proteins upon M-phase exit during the Xenopus laevis oocyte to embryo transition.

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    Marteil, Gaëlle; Gagné, Jean-Philippe; Borsuk, Ewa; Richard-Parpaillon, Laurent; Poirier, Guy G; Kubiak, Jacek Z

    2012-01-01

    Cyclin-dependent kinase 1 (CDK1) is a major M-phase kinase which requires the binding to a regulatory protein, Cyclin B, to be active. CDK1/Cyclin B complex is called M-phase promoting factor (MPF) for its key role in controlling both meiotic and mitotic M-phase of the cell cycle. CDK1 inactivation is necessary for oocyte activation and initiation of embryo development. This complex process requires both Cyclin B polyubiquitination and proteosomal degradation via the ubiquitin-conjugation pathway, followed by the dephosphorylation of the monomeric CDK1 on Thr161. Previous proteomic analyses revealed a number of CDK1-associated proteins in human HeLa cells. It is, however, unknown whether specific partners are involved in CDK1 inactivation upon M-phase exit. To better understand CDK1 regulation during MII-arrest and oocyte activation, we immunoprecipitated (IPed) CDK1 together with its associated proteins from M-phase-arrested and M-phase-exiting Xenopus laevis oocytes. A mass spectrometry (MS) analysis revealed a number of new putative CDK1 partners. Most importantly, the composition of the CDK1-associated complex changed rapidly during M-phase exit. Additionally, an analysis of CDK1 complexes precipitated with beads covered with p9 protein, a fission yeast suc1 homologue well known for its high affinity for CDKs, was performed to identify the most abundant proteins associated with CDK1. The screen was auto-validated by identification of: (i) two forms of CDK1: Cdc2A and B, (ii) a set of Cyclins B with clearly diminishing number of peptides identified upon M-phase exit, (iii) a number of known CDK1 substrates (e.g. peroxiredoxine) and partners (e.g. HSPA8, a member of the HSP70 family) both in IP and in p9 precipitated pellets. In IP samples we also identified chaperones, which can modulate CDK1 three-dimensional structure, as well as calcineurin, a protein necessary for successful oocyte activation. These results shed a new light on CDK1 regulation via a dynamic

  14. Enrichment of Cdk1-cyclins at DNA double-strand breaks stimulates Fun30 phosphorylation and DNA end resection.

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    Chen, Xuefeng; Niu, Hengyao; Yu, Yang; Wang, Jingjing; Zhu, Shuangyi; Zhou, Jianjie; Papusha, Alma; Cui, Dandan; Pan, Xuewen; Kwon, Youngho; Sung, Patrick; Ira, Grzegorz

    2016-04-07

    DNA double-strand breaks (DSBs) are one of the most cytotoxic types of DNA lesion challenging genome integrity. The activity of cyclin-dependent kinase Cdk1 is essential for DSB repair by homologous recombination and for DNA damage signaling. Here we identify the Fun30 chromatin remodeler as a new target of Cdk1. Fun30 is phosphorylated by Cdk1 on Serine 28 to stimulate its functions in DNA damage response including resection of DSB ends. Importantly, Cdk1-dependent phosphorylation of Fun30-S28 increases upon DNA damage and requires the recruitment of Fun30 to DSBs, suggesting that phosphorylation increases in situ at the DNA damage. Consistently, we find that Cdk1 and multiple cyclins become highly enriched at DSBs and that the recruitment of Cdk1 and cyclins Clb2 and Clb5 ensures optimal Fun30 phosphorylation and checkpoint activation. We propose that the enrichment of Cdk1-cyclin complexes at DSBs serves as a mechanism for enhanced targeting and modulating of the activity of DNA damage response proteins.

  15. Parvovirus B19 NS1 protein induces cell cycle arrest at G2-phase by activating the ATR-CDC25C-CDK1 pathway.

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    Peng Xu

    2017-03-01

    Full Text Available Human parvovirus B19 (B19V infection of primary human erythroid progenitor cells (EPCs arrests infected cells at both late S-phase and G2-phase, which contain 4N DNA. B19V infection induces a DNA damage response (DDR that facilitates viral DNA replication but is dispensable for cell cycle arrest at G2-phase; however, a putative C-terminal transactivation domain (TAD2 within NS1 is responsible for G2-phase arrest. To fully understand the mechanism underlying B19V NS1-induced G2-phase arrest, we established two doxycycline-inducible B19V-permissive UT7/Epo-S1 cell lines that express NS1 or NS1mTAD2, and examined the function of the TAD2 domain during G2-phase arrest. The results confirm that the NS1 TAD2 domain plays a pivotal role in NS1-induced G2-phase arrest. Mechanistically, NS1 transactivated cellular gene expression through the TAD2 domain, which was itself responsible for ATR (ataxia-telangiectasia mutated and Rad3-related activation. Activated ATR phosphorylated CDC25C at serine 216, which in turn inactivated the cyclin B/CDK1 complex without affecting nuclear import of the complex. Importantly, we found that the ATR-CHK1-CDC25C-CDK1 pathway was activated during B19V infection of EPCs, and that ATR activation played an important role in B19V infection-induced G2-phase arrest.

  16. Parvovirus B19 NS1 protein induces cell cycle arrest at G2-phase by activating the ATR-CDC25C-CDK1 pathway

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    Xu, Peng; Zhou, Zhe; Xiong, Min; Zou, Wei; Deng, Xuefeng; Ganaie, Safder S.; Peng, Jianxin; Liu, Kaiyu; Wang, Shengqi; Ye, Shui Qing

    2017-01-01

    Human parvovirus B19 (B19V) infection of primary human erythroid progenitor cells (EPCs) arrests infected cells at both late S-phase and G2-phase, which contain 4N DNA. B19V infection induces a DNA damage response (DDR) that facilitates viral DNA replication but is dispensable for cell cycle arrest at G2-phase; however, a putative C-terminal transactivation domain (TAD2) within NS1 is responsible for G2-phase arrest. To fully understand the mechanism underlying B19V NS1-induced G2-phase arrest, we established two doxycycline-inducible B19V-permissive UT7/Epo-S1 cell lines that express NS1 or NS1mTAD2, and examined the function of the TAD2 domain during G2-phase arrest. The results confirm that the NS1 TAD2 domain plays a pivotal role in NS1-induced G2-phase arrest. Mechanistically, NS1 transactivated cellular gene expression through the TAD2 domain, which was itself responsible for ATR (ataxia-telangiectasia mutated and Rad3-related) activation. Activated ATR phosphorylated CDC25C at serine 216, which in turn inactivated the cyclin B/CDK1 complex without affecting nuclear import of the complex. Importantly, we found that the ATR-CHK1-CDC25C-CDK1 pathway was activated during B19V infection of EPCs, and that ATR activation played an important role in B19V infection-induced G2-phase arrest. PMID:28264028

  17. CDK1 structures reveal conserved and unique features of the essential cell cycle CDK

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    Brown, Nicholas R.; Korolchuk, Svitlana; Martin, Mathew P.; Stanley, Will A.; Moukhametzianov, Rouslan; Noble, Martin E. M.; Endicott, Jane A.

    2015-04-01

    CDK1 is the only essential cell cycle CDK in human cells and is required for successful completion of M-phase. It is the founding member of the CDK family and is conserved across all eukaryotes. Here we report the crystal structures of complexes of CDK1-Cks1 and CDK1-cyclin B-Cks2. These structures confirm the conserved nature of the inactive monomeric CDK fold and its ability to be remodelled by cyclin binding. Relative to CDK2-cyclin A, CDK1-cyclin B is less thermally stable, has a smaller interfacial surface, is more susceptible to activation segment dephosphorylation and shows differences in the substrate sequence features that determine activity. Both CDK1 and CDK2 are potential cancer targets for which selective compounds are required. We also describe the first structure of CDK1 bound to a potent ATP-competitive inhibitor and identify aspects of CDK1 structure and plasticity that might be exploited to develop CDK1-selective inhibitors.

  18. CDK-1 Inhibition in G2 Stabilizes Kinetochore-Microtubules in the following Mitosis.

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    Gayek, A Sophia; Ohi, Ryoma

    2016-01-01

    Cell proliferation is driven by cyclical activation of cyclin-dependent kinases (CDKs), which produce distinct biochemical cell cycle phases. Mitosis (M phase) is orchestrated by CDK-1, complexed with mitotic cyclins. During M phase, chromosomes are segregated by a bipolar array of microtubules called the mitotic spindle. The essential bipolarity of the mitotic spindle is established by the kinesin-5 Eg5, but factors influencing the maintenance of spindle bipolarity are not fully understood. Here, we describe an unexpected link between inhibiting CDK-1 before mitosis and bipolar spindle maintenance. Spindles in human RPE-1 cells normally collapse to monopolar structures when Eg5 is inhibited at metaphase. However, we found that inhibition of CDK-1 in the G2 phase of the cell cycle improved the ability of RPE-1 cells to maintain spindle bipolarity without Eg5 activity in the mitosis immediately after release from CDK-1 inhibition. This improved bipolarity maintenance correlated with an increase in the stability of kinetochore-microtubules, the subset of microtubules that link chromosomes to the spindle. The improvement in bipolarity maintenance after CDK-1 inhibition in G2 required both the kinesin-12 Kif15 and increased stability of kinetochore-microtubules. Consistent with increased kinetochore-microtubule stability, we find that inhibition of CDK-1 in G2 impairs mitotic fidelity by increasing the incidence of lagging chromosomes in anaphase. These results suggest that inhibition of CDK-1 in G2 causes unpredicted effects in mitosis, even after CDK-1 inhibition is relieved.

  19. Genetic substitution of Cdk1 by Cdk2 leads to embryonic lethality and loss of meiotic function of Cdk2.

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    Satyanarayana, Ande; Berthet, Cyril; Lopez-Molina, Javier; Coppola, Vincenzo; Tessarollo, Lino; Kaldis, Philipp

    2008-10-01

    It was believed that Cdk2-cyclin E complexes are essential to drive cells through the G1-S phase transition. However, it was discovered recently that the mitotic kinase Cdk1 (Cdc2a) compensates for the loss of Cdk2. In the present study, we tested whether Cdk2 can compensate for the loss of Cdk1. We generated a knockin mouse in which the Cdk2 cDNA was knocked into the Cdk1 locus (Cdk1Cdk2KI). Substitution of both copies of Cdk1 by Cdk2 led to early embryonic lethality, even though Cdk2 was expressed from the Cdk1 locus. In addition, we generated Cdk2-/- Cdk1+/Cdk2KI mice in which one copy of Cdk2 and one copy of Cdk1 were expressed from the Cdk1 locus and the Cdk2 gene was deleted from the endogenous Cdk2 locus. We found that both male and female Cdk2-/- Cdk1+/Cdk2KI mice were sterile, similar to Cdk2-/- mice, even though they expressed the Cdk2 protein from the Cdk1 locus in testes. The translocational and cell cycle properties of knockin Cdk2 in Cdk2-/- Cdk1+/Cdk2KI cells were comparable to those of endogenous Cdk2, but we detected premature transcriptional activation of Cdk1 during liver regeneration in the absence of Cdk2. This study provides evidence of the molecular differences between Cdk2 and Cdk1 and highlights that the timing of transcriptional activation and the genetic locus play important roles in determining the function of Cdk proteins in vivo.

  20. Regulation of a transcription factor network by Cdk1 coordinates late cell cycle gene expression.

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    Landry, Benjamin D; Mapa, Claudine E; Arsenault, Heather E; Poti, Kristin E; Benanti, Jennifer A

    2014-05-02

    To maintain genome stability, regulators of chromosome segregation must be expressed in coordination with mitotic events. Expression of these late cell cycle genes is regulated by cyclin-dependent kinase (Cdk1), which phosphorylates a network of conserved transcription factors (TFs). However, the effects of Cdk1 phosphorylation on many key TFs are not known. We find that elimination of Cdk1-mediated phosphorylation of four S-phase TFs decreases expression of many late cell cycle genes, delays mitotic progression, and reduces fitness in budding yeast. Blocking phosphorylation impairs degradation of all four TFs. Consequently, phosphorylation-deficient mutants of the repressors Yox1 and Yhp1 exhibit increased promoter occupancy and decreased expression of their target genes. Interestingly, although phosphorylation of the transcriptional activator Hcm1 on its N-terminus promotes its degradation, phosphorylation on its C-terminus is required for its activity, indicating that Cdk1 both activates and inhibits a single TF. We conclude that Cdk1 promotes gene expression by both activating transcriptional activators and inactivating transcriptional repressors. Furthermore, our data suggest that coordinated regulation of the TF network by Cdk1 is necessary for faithful cell division.

  1. Distinct Cdk1 requirements during single-strand annealing, noncrossover, and crossover recombination.

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    Camilla Trovesi

    2011-08-01

    Full Text Available Repair of DNA double-strand breaks (DSBs by homologous recombination (HR in haploid cells is generally restricted to S/G2 cell cycle phases, when DNA has been replicated and a sister chromatid is available as a repair template. This cell cycle specificity depends on cyclin-dependent protein kinases (Cdk1 in Saccharomyces cerevisiae, which initiate HR by promoting 5'-3' nucleolytic degradation of the DSB ends. Whether Cdk1 regulates other HR steps is unknown. Here we show that yku70Δ cells, which accumulate single-stranded DNA (ssDNA at the DSB ends independently of Cdk1 activity, are able to repair a DSB by single-strand annealing (SSA in the G1 cell cycle phase, when Cdk1 activity is low. This ability to perform SSA depends on DSB resection, because both resection and SSA are enhanced by the lack of Rad9 in yku70Δ G1 cells. Furthermore, we found that interchromosomal noncrossover recombinants are generated in yku70Δ and yku70Δ rad9Δ G1 cells, indicating that DSB resection bypasses Cdk1 requirement also for carrying out these recombination events. By contrast, yku70Δ and yku70Δ rad9Δ cells are specifically defective in interchromosomal crossover recombination when Cdk1 activity is low. Thus, Cdk1 promotes DSB repair by single-strand annealing and noncrossover recombination by acting mostly at the resection level, whereas additional events require Cdk1-dependent regulation in order to generate crossover outcomes.

  2. Synchronization of interphase events depends neither on mitosis nor on cdk1.

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    Laronne, Ayelet; Rotkopf, Shay; Hellman, Asaf; Gruenbaum, Yosef; Porter, Andrew C G; Brandeis, Michael

    2003-09-01

    Human HT2-19 cells with a conditional cdk1 mutation stop dividing upon cdk1 inactivation and undergo multiple rounds of endoreplication. We show herein that major cell cycle events remain synchronized in these endoreplicating cells. DNA replication alternates with gap phases and cell cycle-specific cyclin E expression is maintained. Centrosomes duplicate in synchrony with chromosome replication, giving rise to polyploid cells with multiple centrosomes. Centrosome migration, a typical prophase event, also takes place in endoreplicating cells. The timing of these events is unaffected by cdk1 inactivation compared with normally dividing cells. Nuclear lamina breakdown, in contrast, previously shown to be dependent on cdk1, does not take place in endoreplicating HT2-19 cells. Moreover, breakdown of all other major components of the nuclear lamina, like the inner nuclear membrane proteins and nuclear pore complexes, seems also to depend on cdk1. Interestingly, the APC/C ubiquitin ligase is activated in these endoreplicating cells by fzr but not by fzy. The oscillations of interphase events are thus independent of cdk1 and of mitosis but may depend on APC/Cfzr activity.

  3. Mitotic-dependent phosphorylation of leukemia-associated RhoGEF (LARG) by Cdk1.

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    Helms, Michelle C; Grabocka, Elda; Martz, Matthew K; Fischer, Christopher C; Suzuki, Nobuchika; Wedegaertner, Philip B

    2016-01-01

    Rho GTPases are integral to the regulation of actin cytoskeleton-dependent processes, including mitosis. Rho and leukemia-associated Rho guanine-nucleotide exchange factor (LARG), also known as ARHGEF12, are involved in mitosis as well as diseases such as cancer and heart disease. Since LARG has a role in mitosis and diverse signaling functions beyond mitosis, it is important to understand the regulation of the protein through modifications such as phosphorylation. Here we report that LARG undergoes a mitotic-dependent and cyclin-dependent kinase 1 (Cdk1) inhibitor-sensitive phosphorylation. Additionally, LARG is phosphorylated at the onset of mitosis and dephosphorylated as cells exit mitosis, concomitant with Cdk1 activity. Furthermore, using an in vitro kinase assay, we show that LARG can be directly phosphorylated by Cdk1. Through expression of phosphonull mutants that contain non-phosphorylatable alanine mutations at potential Cdk1 S/TP sites, we demonstrate that LARG phosphorylation occurs in both termini. Using phosphospecific antibodies, we confirm that two sites, serine 190 and serine 1176, are phosphorylated during mitosis in a Cdk1-dependent manner. In addition, these phosphospecific antibodies show phosphorylated LARG at specific mitotic locations, namely the mitotic organizing centers and flanking the midbody. Lastly, RhoA activity assays reveal that phosphonull LARG is more active in cells than phosphomimetic LARG. Our data thus identifies LARG as a phosphoregulated RhoGEF during mitosis.

  4. Brain-derived neurotrophic factor-dependent cdk1 inhibition prevents G2/M progression in differentiating tetraploid neurons.

    Science.gov (United States)

    Ovejero-Benito, María C; Frade, José M

    2013-01-01

    Neurodegeneration is often associated with DNA synthesis in neurons, the latter usually remaining for a long time as tetraploid cells before dying by apoptosis. The molecular mechanism preventing G2/M transition in these neurons remains unknown, but it may be reminiscent of the mechanism that maintains tetraploid retinal ganglion cells (RGCs) in a G2-like state during normal development, thus preventing their death. Here we show that this latter process, known to depend on brain-derived neurotrophic factor (BDNF), requires the inhibition of cdk1 by TrkB. We demonstrate that a subpopulation of chick RGCs previously shown to become tetraploid co-expresses TrkB and cdk1 in vivo. By using an in vitro system that recapitulates differentiation and cell cycle re-entry of chick retinal neurons we show that BDNF, employed at concentrations specific for the TrkB receptor, reduces the expression of cdk1 in TrkB-positive, differentiating neurons. In this system, BDNF also inhibits the activity of both endogenous cdk1 and exogenously-expressed cdk1/cyclin B1 complex. This inhibition correlates with the phosphorylation of cdk1 at Tyr15, an effect that can be prevented with K252a, a tyrosine kinase inhibitor commonly used to prevent the activity of neurotrophins through their Trk receptors. The effect of BDNF on cdk1 activity is Tyr15-specific since BDNF cannot prevent the activity of a constitutively active form of cdk1 (Tyr15Phe) when expressed in differentiating retinal neurons. We also show that BDNF-dependent phosphorylation of cdk1 at Tyr15 could not be blocked with MK-1775, a Wee1-selective inhibitor, indicating that Tyr15 phosphorylation in cdk1 does not seem to occur through the canonical mechanism observed in proliferating cells. We conclude that the inhibition of both expression and activity of cdk1 through a BDNF-dependent mechanism contributes to the maintenance of tetraploid RGCs in a G2-like state.

  5. NPM phosphorylation stimulates Cdk1, overrides G2/M checkpoint and increases leukemic blasts in mice.

    Science.gov (United States)

    Du, Wei; Zhou, Yun; Pike, Suzette; Pang, Qishen

    2010-02-01

    An elevated level of nucleophosmin (NPM) is often found in actively proliferative cells including human tumors. To identify the regulatory role for NPM phosphorylation in proliferation and cell cycle control, a series of mutants targeting the consensus cyclin-dependent kinase (CDK) phosphorylation sites was created to mimic or abrogate either single-site or multi-site phosphorylation. Simultaneous inactivation of two CDK phosphorylation sites at Ser10 and Ser70 (NPM-AA) induced G(2)/M cell cycle arrest, phosphorylation of Cdk1 at Tyr15 (Cdc2(Tyr15)) and increased cytoplasmic accumulation of Cdc25C. Strikingly, stress-induced Cdk1(Tyr15) and Cdc25C sequestration was suppressed by expression of a phosphomimetic NPM mutant created on the same CDK sites (S10E/S70E, NPM-EE). Further analysis revealed that phosphorylation of NPM at both Ser10 and Ser70 was required for proper interaction between Cdk1 and Cdc25C. Moreover, NPM-EE directly bound to Cdc25C and prevented phosphorylation of Cdc25C at Ser216 during mitosis. Finally, NPM-EE overrided stress-induced G(2)/M arrest and increased leukemia blasts in a NOD/SCID xenograft model. Thus, these findings reveal a novel function of NPM on regulation of cell cycle progression, in which phosphorylation of NPM controls cell cycle progression at G(2)/M transition through modulation of Cdk1 and Cdc25C activities.

  6. Cdk1 Restrains NHEJ through Phosphorylation of XRCC4-like Factor Xlf1

    Directory of Open Access Journals (Sweden)

    Pierre Hentges

    2014-12-01

    Full Text Available Eukaryotic cells use two principal mechanisms for repairing DNA double-strand breaks (DSBs: homologous recombination (HR and nonhomologous end-joining (NHEJ. DSB repair pathway choice is strongly regulated during the cell cycle. Cyclin-dependent kinase 1 (Cdk1 activates HR by phosphorylation of key recombination factors. However, a mechanism for regulating the NHEJ pathway has not been established. Here, we report that Xlf1, a fission yeast XLF ortholog, is a key regulator of NHEJ activity in the cell cycle. We show that Cdk1 phosphorylates residues in the C terminus of Xlf1 over the course of the cell cycle. Mutation of these residues leads to the loss of Cdk1 phosphorylation, resulting in elevated levels of NHEJ repair in vivo. Together, these data establish that Xlf1 phosphorylation by Cdc2Cdk1 provides a molecular mechanism for downregulation of NHEJ in fission yeast and indicates that XLF is a key regulator of end-joining processes in eukaryotic organisms.

  7. Suppression of Vimentin Phosphorylation by the Avian Reovirus p17 through Inhibition of CDK1 and Plk1 Impacting the G2/M Phase of the Cell Cycle

    Science.gov (United States)

    Chiu, Hung-Chuan; Huang, Wei-Ru; Liao, Tsai-Ling; Wu, Hung-Yi; Munir, Muhammad; Shih, Wing-Ling; Liu, Hung-Jen

    2016-01-01

    The p17 protein of avian reovirus (ARV) causes cell cycle retardation in a variety of cell lines; however, the underlying mechanism(s) by which p17 regulates the cell cycle remains largely unknown. We demonstrate for the first time that p17 interacts with CDK1 and vimentin as revealed by reciprocal co-immunoprecipitation and GST pull-down assays. Both in vitro and in vivo studies indicated that direct interaction of p17 and CDK1/vimentin was mapped within the amino terminus (aa 1–60) of p17 and central region (aa 27–118) of CDK1/vimentin. Furthermore, p17 was found to occupy the Plk1-binding site within the vimentin, thereby blocking Plk1 recruitment to CDK1-induced vimentin phosphorylation at Ser 56. Interaction of p17 to CDK1 or vimentin interferes with CDK1-catalyzed phosphorylation of vimentin at Ser 56 and subsequently vimentin phosphorylation at Ser 82 by Plk1. Furthermore, we have identified upstream signaling pathways and cellular factor(s) targeted by p17 and found that p17 regulates inhibitory phosphorylation of CDK1 and blocks vimentin phosphorylation at Ser 56 and Ser 82. The p17-mediated inactivation of CDK1 is dependent on several mechanisms, which include direct interaction with CDK1, p17-mediated suppression of Plk1 by activating the Tpr/p53 and ATM/Chk1/PP2A pathways, and p17-mediated cdc25C degradation via an ubiquitin- proteasome pathway. Additionally, depletion of p53 with a shRNA as well as inhibition of ATM and vimentin by inhibitors diminished virus yield while Tpr and CDK1 knockdown increased virus yield. Taken together, results demonstrate that p17 suppresses both CDK1 and Plk1functions, disrupts vimentin phosphorylation, causes G2/M cell cycle arrest and thus benefits virus replication. PMID:27603133

  8. Triple negative breast cancer therapy with CDK1 siRNA delivered by cationic lipid assisted PEG-PLA nanoparticles.

    Science.gov (United States)

    Liu, Yang; Zhu, Yan-Hua; Mao, Cheng-Qiong; Dou, Shuang; Shen, Song; Tan, Zi-Bin; Wang, Jun

    2014-10-28

    There is no effective clinical therapy yet for triple-negative breast cancer (TNBC) without particular human epidermal growth factor receptor-2, estrogen and progesterone receptor expression. In this study, we report a molecularly targeted and synthetic lethality-based siRNA therapy for TNBC treatment, using cationic lipid assisted poly(ethylene glycol)-b-poly(d,l-lactide) (PEG-PLA) nanoparticles as the siRNA carrier. It is demonstrated that only in c-Myc overexpressed TNBC cells, while not in normal mammary epithelial cells, delivery of siRNA targeting cyclin-dependent kinase 1 (CDK1) with the nanoparticle carrier (NPsiCDK1) induces cell viability decreasing and cell apoptosis through RNAi-mediated CDK1 expression inhibition, indicating the synthetic lethality between c-Myc with CDK1 in TNBC cells. Moreover, systemic delivery of NPsiCDK1 is able to suppress tumor growth in mice bearing SUM149 and BT549 xenograft and cause no systemic toxicity or activate the innate immune response, suggesting the therapeutic promise with such nanoparticles carrying siCDK1 for c-Myc overexpressed triple negative breast cancer.

  9. Cdk1 phosphorylation of the kinetochore protein Nsk1 prevents error-prone chromosome segregation.

    Science.gov (United States)

    Chen, Jun-Song; Lu, Lucy X; Ohi, Melanie D; Creamer, Kevin M; English, Chauca; Partridge, Janet F; Ohi, Ryoma; Gould, Kathleen L

    2011-11-14

    Cdk1 controls many aspects of mitotic chromosome behavior and spindle microtubule (MT) dynamics to ensure accurate chromosome segregation. In this paper, we characterize a new kinetochore substrate of fission yeast Cdk1, Nsk1, which promotes proper kinetochore-MT (k-MT) interactions and chromosome movements in a phosphoregulated manner. Cdk1 phosphorylation of Nsk1 antagonizes Nsk1 kinetochore and spindle localization during early mitosis. A nonphosphorylatable Nsk1 mutant binds prematurely to kinetochores and spindle, cementing improper k-MT attachments and leading to high rates of lagging chromosomes that missegregate. Accordingly, cells lacking nsk1 exhibit synthetic growth defects with mutations that disturb MT dynamics and/or kinetochore structure, and lack of proper phosphoregulation leads to even more severe defects. Intriguingly, Nsk1 is stabilized by binding directly to the dynein light chain Dlc1 independently of the dynein motor, and Nsk1-Dlc1 forms chainlike structures in vitro. Our findings establish new roles for Cdk1 and the Nsk1-Dlc1 complex in regulating the k-MT interface and chromosome segregation.

  10. CDK1 Inhibition Targets the p53-NOXA-MCL1 Axis, Selectively Kills Embryonic Stem Cells, and Prevents Teratoma Formation

    Directory of Open Access Journals (Sweden)

    Noelle E. Huskey

    2015-03-01

    Full Text Available Embryonic stem cells (ESCs have adopted an accelerated cell-cycle program with shortened gap phases and precocious expression of cell-cycle regulatory proteins, including cyclins and cyclin-dependent kinases (CDKs. We examined the effect of CDK inhibition on the pathways regulating proliferation and survival of ESCs. We found that inhibiting cyclin-dependent kinase 1 (CDK1 leads to activation of the DNA damage response, nuclear p53 stabilization, activation of a subset of p53 target genes including NOXA, and negative regulation of the anti-apoptotic protein MCL1 in human and mouse ESCs, but not differentiated cells. We demonstrate that MCL1 is highly expressed in ESCs and loss of MCL1 leads to ESC death. Finally, we show that clinically relevant CDK1 inhibitors prevent formation of ESC-derived tumors and induce necrosis in established ESC-derived tumors. Our data demonstrate that ES cells are uniquely sensitive to CDK1 inhibition via a p53/NOXA/MCL1 pathway.

  11. Proteomics reveals a switch in CDK1-associated proteins upon M-phase exit during the Xenopus laevis oocyte to embryo transition.

    OpenAIRE

    Marteil, Gaëlle; Gagné, Jean-Philippe; Borsuk, Ewa; Richard-Parpaillon, Laurent; Poirier, Guy,; Kubiak, Jacek,

    2012-01-01

    International audience; Cyclin-dependent kinase 1 (CDK1) is a major M-phase kinase which requires the binding to a regulatory protein, Cyclin B, to be active. CDK1/Cyclin B complex is called M-phase promoting factor (MPF) for its key role in controlling both meiotic and mitotic M-phase of the cell cycle. CDK1 inactivation is necessary for oocyte activation and initiation of embryo development. This complex process requires both Cyclin B polyubiquitination and proteosomal degradation via the u...

  12. Cdk1/cyclin B-mediated phosphorylation stabilizes SREBP1 during mitosis.

    Science.gov (United States)

    Bengoechea-Alonso, Maria T; Ericsson, Johan

    2006-08-01

    Members of the sterol regulatory element-binding protein (SREBP) family of transcription factors control the biosynthesis of cholesterol and other lipids, and lipid synthesis is critical for cell growth and proliferation. We recently found that the mature forms of SREBP1a and SREBP1c are hyperphosphorylated in mitotic cells, giving rise to a phosphoepitope recognized by the mitotic protein monoclonal-2 (MPM-2) antibody. In addition, we found that mature SREBP1 was stabilized in a phosphorylation-dependent manner during mitosis. We have now mapped the major MPM-2 epitope to a serine residue, S439, in the C terminus of mature SREBP1. Using phosphorylation-specific antibodies, we demonstrate that endogenous SREBP1 is phosphorylated on S439 specifically during mitosis. Mature SREBP1 interacts with the Cdk1/cyclin B complex in mitotic cells and we demonstrate that Cdk1 phosphorylates S439, both in vitro and in vivo. Our results suggest that Cdk1-mediated phosphorylation of S439 stabilizes mature SREBP1 during mitosis, thereby preserving a critical pool of active transcription factors to support lipid synthesis. Taken together with our previous work, the current study suggests that SREBP1 may provide a link between lipid synthesis, proliferation and cell growth. This hypothesis was supported by our observation that siRNA-mediated inactivation of SREBP1 arrested cells in the G(1) phase of the cell cycle, thereby attenuating cell growth.

  13. Reduction of phosphorylated Thr-161 Cdk1 level participates in roscovitine-induced Fas ligand-mediated apoptosis in rat eggs cultured in vitro.

    Science.gov (United States)

    Tripathi, Anima; Chaube, Shail K

    2015-02-01

    The present study was aimed to find out whether roscovitine reduces phosphorylated Thr-161 of cyclin-dependent kinase 1 (Cdk1) level and induces egg apoptosis through Fas ligand (FasL)-mediated pathway. For this purpose, ovulated eggs were cultured in media 199 with or without various concentrations of roscovitine (0, 25, 50, 100, 200 μM) for 3 h in vitro. The morphological apoptotic changes, phosphorylation status of Cdk1, FasL concentration, caspase-8 and caspase-3 activities, and DNA fragmentation were analyzed. Data of the present study suggest that roscovitine significantly reduced Thr-161 phosphorylated Cdk1 level without altering the total level of Cdk1 and induced cytoplasmic fragmentation, a morphological apoptotic feature in a concentration-dependent manner. The roscovitine-induced cytoplasmic fragmentation was associated with increased FasL concentration. The increased FasL concentration induced caspase-8 followed by caspase-3 activities. The increased caspases activity finally induced DNA fragmentation in eggs that showed cytoplasmic fragmentation. Taken together, these results suggest that roscovitine reduced phosphorylated Thr-161 of Cdk1 level and induces apoptosis through FasL-mediated pathway in rat eggs cultured in vitro.

  14. Millepachine, a novel chalcone, induces G2/M arrest by inhibiting CDK1 activity and causing apoptosis via ROS-mitochondrial apoptotic pathway in human hepatocarcinoma cells in vitro and in vivo.

    Science.gov (United States)

    Wu, Wenshuang; Ye, Haoyu; Wan, Li; Han, Xiaolei; Wang, Guangcheng; Hu, Jia; Tang, Minhai; Duan, Xingmei; Fan, Yi; He, Shichao; Huang, Li; Pei, Heying; Wang, Xuewei; Li, Xiuxia; Xie, Caifeng; Zhang, Ronghong; Yuan, Zhu; Mao, Yongqiu; Wei, Yuquan; Chen, Lijuan

    2013-07-01

    In this study, we reported millepachine (MIL), a novel chalcone compound for the first time isolated from Millettia pachycarpa Benth (Leguminosae), induced cell cycle arrest and apoptosis in human hepatocarcinoma cells in vitro and in vivo. In in vitro screening experiments, MIL showed strong antiproliferation activity in several human cancer cell lines, especially in HepG2 cells with an IC50 of 1.51 µM. Therefore, we chose HepG2 and SK-HEP-1 cells to study MIL's antitumor mechanism. Flow cytometry showed that MIL induced a G2/M arrest and apoptosis in a dose-dependent manner. Western blot demonstrated that MIL-induced G2/M arrest was correlated with the inhibition of cyclin-dependent kinase 1 activity, including a remarkable decrease in cell division cycle (cdc) 2 synthesis, the accumulation of phosphorylated-Thr14 and decrease of phosphorylation at Thr161 of cdc2. This effect was associated with the downregulation of cdc25C and upmodulation of checkpoint kinase 2 in response to DNA damage. MIL also activated caspase 9 and caspase 3, and significantly increased the ratio of Bax/Bcl-2 and stimulated the release of cytochrome c into cytosol, suggesting MIL induced apoptosis via mitochondrial apoptotic pathway. Associated with those effects, MIL also induced the generation of reactive oxygen species. In HepG2 tumor-bearing mice models, MIL remarkably and dose dependently inhibited tumor growth. Treatment of mice with MIL (20mg/kg intravenous [i.v.]) caused more than 65% tumor inhibition without cardiac damage compared with 47.57% tumor reduction by 5mg/kg i.v. doxorubicin with significant cardiac damage. These effects suggested that MIL and its easily modified structural derivative might be a potential lead compound for antitumor drug.

  15. The Set1/COMPASS histone H3 methyltransferase helps regulate mitosis with the CDK1 and NIMA mitotic kinases in Aspergillus nidulans.

    Science.gov (United States)

    Govindaraghavan, Meera; Anglin, Sarah Lea; Osmani, Aysha H; Osmani, Stephen A

    2014-08-01

    Mitosis is promoted and regulated by reversible protein phosphorylation catalyzed by the essential NIMA and CDK1 kinases in the model filamentous fungus Aspergillus nidulans. Protein methylation mediated by the Set1/COMPASS methyltransferase complex has also been shown to regulate mitosis in budding yeast with the Aurora mitotic kinase. We uncover a genetic interaction between An-swd1, which encodes a subunit of the Set1 protein methyltransferase complex, with NIMA as partial inactivation of nimA is poorly tolerated in the absence of swd1. This genetic interaction is additionally seen without the Set1 methyltransferase catalytic subunit. Importantly partial inactivation of NIMT, a mitotic activator of the CDK1 kinase, also causes lethality in the absence of Set1 function, revealing a functional relationship between the Set1 complex and two pivotal mitotic kinases. The main target for Set1-mediated methylation is histone H3K4. Mutational analysis of histone H3 revealed that modifying the H3K4 target residue of Set1 methyltransferase activity phenocopied the lethality seen when either NIMA or CDK1 are partially functional. We probed the mechanistic basis of these genetic interactions and find that the Set1 complex performs functions with CDK1 for initiating mitosis and with NIMA during progression through mitosis. The studies uncover a joint requirement for the Set1 methyltransferase complex with the CDK1 and NIMA kinases for successful mitosis. The findings extend the roles of the Set1 complex to include the initiation of mitosis with CDK1 and mitotic progression with NIMA in addition to its previously identified interactions with Aurora and type 1 phosphatase in budding yeast.

  16. Phosphorylation of AIB1 at Mitosis Is Regulated by CDK1/CYCLIN B

    Science.gov (United States)

    Ferrero, Macarena; Ferragud, Juan; Orlando, Leonardo; Valero, Luz; Sánchez del Pino, Manuel; Farràs, Rosa; Font de Mora, Jaime

    2011-01-01

    Background Although the AIB1 oncogene has an important role during the early phase of the cell cycle as a coactivator of E2F1, little is known about its function during mitosis. Methodology/Principal Findings Mitotic cells isolated by nocodazole treatment as well as by shake-off revealed a post-translational modification occurring in AIB1 specifically during mitosis. This modification was sensitive to the treatment with phosphatase, suggesting its modification by phosphorylation. Using specific inhibitors and in vitro kinase assays we demonstrate that AIB1 is phosphorylated on Ser728 and Ser867 by Cdk1/cyclin B at the onset of mitosis and remains phosphorylated until exit from M phase. Differences in the sensitivity to phosphatase inhibitors suggest that PP1 mediates dephosphorylation of AIB1 at the end of mitosis. The phosphorylation of AIB1 during mitosis was not associated with ubiquitylation or degradation, as confirmed by western blotting and flow cytometry analysis. In addition, luciferase reporter assays showed that this phosphorylation did not alter the transcriptional properties of AIB1. Importantly, fluorescence microscopy and sub-cellular fractionation showed that AIB1 phosphorylation correlated with the exclusion from the condensed chromatin, thus preventing access to the promoters of AIB1-dependent genes. Phospho-specific antibodies developed against Ser728 further demonstrated the presence of phosphorylated AIB1 only in mitotic cells where it was localized preferentially in the periphery of the cell. Conclusions Collectively, our results describe a new mechanism for the regulation of AIB1 during mitosis, whereby phosphorylation of AIB1 by Cdk1 correlates with the subcellular redistribution of AIB1 from a chromatin-associated state in interphase to a more peripheral localization during mitosis. At the exit of mitosis, AIB1 is dephosphorylated, presumably by PP1. This exclusion from chromatin during mitosis may represent a mechanism for governing the

  17. Cdk1, PKCδ and calcineurin-mediated Drp1 pathway contributes to mitochondrial fission-induced cardiomyocyte death

    Energy Technology Data Exchange (ETDEWEB)

    Zaja, Ivan [Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Bai, Xiaowen, E-mail: xibai@mcw.edu [Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Liu, Yanan; Kikuchi, Chika; Dosenovic, Svjetlana; Yan, Yasheng; Canfield, Scott G. [Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Bosnjak, Zeljko J. [Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States)

    2014-10-31

    Highlights: • Drp1-mediated increased mitochondrial fission but not fusion is involved the cardiomyocyte death during anoxia-reoxygenation injury. • Reactive oxygen species are upstream initiators of mitochondrial fission. • Increased mitochondrial fission is resulted from Cdk1-, PKCδ-, and calcineurin-mediated Drp1 pathways. - Abstract: Myocardial ischemia–reperfusion (I/R) injury is one of the leading causes of death and disability worldwide. Mitochondrial fission has been shown to be involved in cardiomyocyte death. However, molecular machinery involved in mitochondrial fission during I/R injury has not yet been completely understood. In this study we aimed to investigate molecular mechanisms of controlling activation of dynamin-related protein 1 (Drp1, a key protein in mitochondrial fission) during anoxia-reoxygenation (A/R) injury of HL1 cardiomyocytes. A/R injury induced cardiomyocyte death accompanied by the increases of mitochondrial fission, reactive oxygen species (ROS) production and activated Drp1 (pSer616 Drp1), and decrease of inactivated Drp1 (pSer637 Drp1) while mitochondrial fusion protein levels were not significantly changed. Blocking Drp1 activity with mitochondrial division inhibitor mdivi1 attenuated cell death, mitochondrial fission, and Drp1 activation after A/R. Trolox, a ROS scavenger, decreased pSer616 Drp1 level and mitochondrial fission after A/R. Immunoprecipitation assay further indicates that cyclin dependent kinase 1 (Cdk1) and protein kinase C isoform delta (PKCδ) bind Drp1, thus increasing mitochondrial fission. Inhibiting Cdk1 and PKCδ attenuated the increases in pSer616 Drp1, mitochondrial fission, and cardiomyocyte death. FK506, a calcineurin inhibitor, blocked the decrease in expression of inactivated pSer637 Drp1 and mitochondrial fission. Our findings reveal the following novel molecular mechanisms controlling mitochondrial fission during A/R injury of cardiomyocytes: (1) ROS are upstream initiators of

  18. CDK-1 and two B-type cyclins promote PAR-6 stabilization during polarization of the early C. elegans embryo.

    Directory of Open Access Journals (Sweden)

    Alexia Rabilotta

    Full Text Available In the C. elegans embryo, formation of an antero-posterior axis of polarity relies on signaling by the conserved PAR proteins, which localize asymmetrically in two mutually exclusive groups at the embryonic cortex. Depletion of any PAR protein causes a loss of polarity and embryonic lethality. A genome-wide RNAi screen previously identified two B-type cyclins, cyb-2.1 and cyb-2.2, as suppressors of par-2(it5ts lethality. We found that the loss of cyb-2.1 or cyb-2.2 suppressed the lethality and polarity defects of par-2(it5ts mutants and that these cyclins act in cell polarity with their cyclin-dependent kinase partner, CDK-1. Interestingly, cyb-2.1; cyb-2.2 double mutants did not show defects in cell cycle progression or timing of polarity establishment, suggesting that they regulate polarity independently of their typical role in cell cycle progression. Loss of both cyclin genes or of cdk-1 resulted in a decrease in PAR-6 levels in the embryo. Furthermore, the activity of the cullin CUL-2 was required to achieve suppression of par-2 lethality when both cyclins were absent. Our results support a model in which CYB-2.1/2/CDK-1 antagonize CUL-2 activity to promote stabilization of PAR-6 levels during polarization of the early C. elegans embryo. They also suggest that CYB-2.1 and CYB-2.2 contribute to the coupling of cell cycle progression and asymmetric segregation of cell fate determinants.

  19. Nuclear phosphoproteomics analysis reveals that CDK1/2 are involved in EGF-regulated constitutive pre-mRNA splicing in MDA-MB-468 cells.

    Science.gov (United States)

    Chen, Xianwei; Guo, Dan; Zhu, Yinghui; Xian, Feng; Liu, Siqi; Wu, Lin; Lou, Xiaomin

    2016-06-01

    The epidermal growth factor (EGF) receptor (EGFR) pathway is one of the most dysregulated and extensively investigated signaling pathways in human cancers and plays important roles in the regulation of nuclear functions through both cytoplasmic and nuclear EGFR pathways. However, the current understanding of the nuclear phosphorylation responses to activated EGFR pathways remains limited. In the present study, phosphoproteomics analysis revealed the increased phosphorylation of 90 nuclear proteins, primarily involved in RNA processing, pre-mRNA splicing and cell cycle regulation, upon EGF stimulation in MDA-MB-468 cells. Cellular splicing assays of the β-globin (HBB) minigene confirmed that EGF induced constitutive pre-mRNA splicing. Further analysis of phosphoproteomics data identified multiple CDK1/2 substrates in pre-mRNA splicing-related proteins, and both CDK1/2 inhibitors and CDK1/2 knockdowns reduced EGF-regulated pre-mRNA splicing. In conclusion, the results of the present study provide evidence that CDK1/2 participate in the regulation of constitutive pre-mRNA splicing by EGF stimulation in MDA-MB-468 cells. In this study, we successfully carried out a survey of nuclear phosphorylation changes in response to EGF stimulation. The results from the functional category analysis and pre-mRNA splicing assay strongly indicated that EGFR activation increased constitutive pre-mRNA splicing in MDA-MB-468 cells, revealing additional role of EGFR on regulation of mRNA maturation beyond alternative pre-mRNA splicing reported by previous studies. Furthermore, we found that CDK1/2 participated in constitutive pre-mRNA splicing regulation by EGF in MDA-MB-468 cells. Our study provides new knowledge for understanding the regulation of constitutive pre-mRNA splicing by EGF stimulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Metabolism and pharmacokinetics of 8-hydroxypiperidinylmethyl-baicalein (BA-j) as a novel selective CDK1 inhibitor in monkey.

    Science.gov (United States)

    Guo, Hong-Min; Sun, Yu-Ming; Zhang, Shi-Xuan; Ju, Xiu-Lan; Xie, Ai-Yun; Li, Jing; Zou, Liang; Sun, Xiao-Dan; Li, Hai-Liang; Zheng, Yang

    2015-12-01

    Cyclin-dependent kinase 1 (CDK1) is the only necessary CDK in the cell proliferation process and a new target in the research and development of anti-cancer drugs. 8-Hydroxypiperidinemethyl-baicalein (BA-j) is a Mannich base derivative of baicalein (BA) isolated from Scutellaria baicalensis, as a novel selective CDK1 inhibitor. 12 metabolites of BA-j in the monkey urine were identified by LC-MS-MS and (1)H NMR. The major metabolic pathways of BA-j, by capturing oxygen free radicals ((.)O2(-)) and releasing peroxides (H2O2), are degraded into active intermediate metabolite dihydroflavonol, then into main metabolite M179 by Shiff reaction, second metabolite M264 by sulfation, trace amount of metabolite M559 by glucuronidation UGT1A9, and without metabolism by CYP3A4. The metabolic process of BA-j by regulating intracellular reactive oxygen species (ROS) was related with BA-j selectively inducing apoptosis in cancer cells. Pharmacokinetics of 10mg/kg oral BA-j in monkey by HPLC-UV was best fitted to a two-compartment open model, with t1/2(β) of 4.2h, Cmax 25.4μM at 2h, and Vd 12.6L, meaning the drug distributing widely in body fluids with no special selectivity to certain tissues, and being able to permeate through the blood-brain barrier. The protein binding rate of BA-j was 91.8%. BA-j has excellent druggability for oral administration or injection, and it may be developed into a novel anti-cancer drug as a selective CDK1 inhibitor.

  1. Phosphorylation by Cdk1 induces Plk1-mediated vimentin phosphorylation during mitosis

    NARCIS (Netherlands)

    Yamaguchi, Tomoya; Goto, Hidemasa; Yokoyama, Tomoya; Silljé, Herman; Hanisch, Anja; Uldschmid, Andreas; Takai, Yasushi; Oguri, Takashi; Nigg, Erich A; Inagaki, Masaki

    2005-01-01

    Several kinases phosphorylate vimentin, the most common intermediate filament protein, in mitosis. Aurora-B and Rho-kinase regulate vimentin filament separation through the cleavage furrow-specific vimentin phosphorylation. Cdk1 also phosphorylates vimentin from prometaphase to metaphase, but its si

  2. Regulation of the G1/S Transition in Hepatocytes: Involvement of the Cyclin-Dependent Kinase Cdk1 in the DNA Replication

    Directory of Open Access Journals (Sweden)

    Anne Corlu

    2012-01-01

    Full Text Available A singular feature of adult differentiated hepatocytes is their capacity to proliferate allowing liver regeneration. This review emphasizes the literature published over the last 20 years that established the most important pathways regulating the hepatocyte cell cycle. Our article also aimed at illustrating that many discoveries in this field benefited from the combined use of in vivo models of liver regeneration and in vitro models of primary cultures of human and rodent hepatocytes. Using these models, our laboratory has contributed to decipher the different steps of the progression into the G1 phase and the commitment to S phase of proliferating hepatocytes. We identified the mitogen dependent restriction point located at the two-thirds of the G1 phase and the concomitant expression and activation of both Cdk1 and Cdk2 at the G1/S transition. Furthermore, we demonstrated that these two Cdks contribute to the DNA replication. Finally, we provided strong evidences that Cdk1 expression and activation is correlated to extracellular matrix degradation upon stimulation by the pro-inflammatory cytokine TNFα leading to the identification of a new signaling pathway regulating Cdk1 expression at the G1/S transition. It also further confirms the well-orchestrated regulation of liver regeneration via multiple extracellular signals and pathways.

  3. p21 Inhibits Cdk1 in the absence of Cdk2 to maintain the G1/S phase DNA damage checkpoint.

    Science.gov (United States)

    Satyanarayana, Ande; Hilton, Mary Beth; Kaldis, Philipp

    2008-01-01

    Cdk1 was proposed to compensate for the loss of Cdk2. Here we present evidence that this is possible due to premature translocation of Cdk1 from the cytoplasm to the nucleus in the absence of Cdk2. We also investigated the consequence of loss of Cdk2 on the maintenance of the G1/S DNA damage checkpoint. Cdk2(-/-) mouse embryonic fibroblasts in vitro as well as regenerating liver cells after partial hepatectomy (PH) in Cdk2(-/-) mice, arrest promptly at the G1/S checkpoint in response to gamma-irradiation due to activation of p53 and p21 inhibiting Cdk1. Furthermore re-entry into S phase after irradiation was delayed in Cdk2(-/-) cells due to prolonged and impaired DNA repair activity. In addition, Cdk2(-/-) mice were more sensitive to lethal irradiation compared to wild-type and displayed delayed resumption of DNA replication in regenerating liver cells. Our results suggest that the G1/S DNA damage checkpoint is intact in the absence of Cdk2, but Cdk2 is important for proper repair of the damaged DNA.

  4. Hyperphosphorylation by cyclin B/CDK1 in mitosis resets CUX1 DNA binding clock at each cell cycle.

    Science.gov (United States)

    Sansregret, Laurent; Gallo, David; Santaguida, Marianne; Leduy, Lam; Harada, Ryoko; Nepveu, Alain

    2010-10-22

    The p110 CUX1 homeodomain protein participates in the activation of DNA replication genes in part by increasing the affinity of E2F factors for the promoters of these genes. CUX1 expression is very weak in quiescent cells and increases during G(1). Biochemical activities associated with transcriptional activation by CUX1 are potentiated by post-translational modifications in late G(1), notably a proteolytic processing event that generates p110 CUX1. Constitutive expression of p110 CUX1, as observed in some transformed cells, leads to accelerated entry into the S phase. In this study, we investigated the post-translation regulation of CUX1 during mitosis and the early G(1) phases of proliferating cells. We observed a major electrophoretic mobility shift and a complete inhibition of DNA binding during mitosis. We show that cyclin B/CDK1 interacts with CUX1 and phosphorylates it at multiple sites. Serine to alanine replacement mutations at 10 SP dipeptide sites were required to restore DNA binding in mitosis. Passage into G(1) was associated with the degradation of some p110 CUX1 proteins, and the remaining proteins were gradually dephosphorylated. Indirect immunofluorescence and subfractionation assays using a phospho-specific antibody showed that most of the phosphorylated protein remained in the cytoplasm, whereas the dephosphorylated protein was preferentially located in the nucleus. Globally, our results indicate that the hyperphosphorylation of CUX1 by cyclin B/CDK1 inhibits its DNA binding activity in mitosis and interferes with its nuclear localization following cell division and formation of the nuclear membrane, whereas dephosphorylation and de novo synthesis contribute to gradually restore CUX1 expression and activity in G(1).

  5. NANOG Is Multiply Phosphorylated and Directly Modified by ERK2 and CDK1 In Vitro

    Directory of Open Access Journals (Sweden)

    Justin Brumbaugh

    2014-01-01

    Full Text Available NANOG is a divergent homeobox protein and a core component of the transcriptional circuitry that sustains pluripotency and self-renewal. Although NANOG has been extensively studied on the transcriptional level, little is known regarding its posttranslational regulation, likely due to its low abundance and challenging physical properties. Here, we identify eleven phosphorylation sites on endogenous human NANOG, nine of which mapped to single amino acids. To screen for the signaling molecules that impart these modifications, we developed the multiplexed assay for kinase specificity (MAKS. MAKS simultaneously tests activity for up to ten kinases while directly identifying the substrate and exact site of phosphorylation. Using MAKS, we discovered site-specific phosphorylation by ERK2 and CDK1/CyclinA2, providing a putative link between key signaling pathways and NANOG.

  6. Phosphorylation of EB2 by Aurora B and CDK1 ensures mitotic progression and genome stability.

    Science.gov (United States)

    Iimori, Makoto; Watanabe, Sugiko; Kiyonari, Shinichi; Matsuoka, Kazuaki; Sakasai, Ryo; Saeki, Hiroshi; Oki, Eiji; Kitao, Hiroyuki; Maehara, Yoshihiko

    2016-03-31

    Temporal regulation of microtubule dynamics is essential for proper progression of mitosis and control of microtubule plus-end tracking proteins by phosphorylation is an essential component of this regulation. Here we show that Aurora B and CDK1 phosphorylate microtubule end-binding protein 2 (EB2) at multiple sites within the amino terminus and a cluster of serine/threonine residues in the linker connecting the calponin homology and end-binding homology domains. EB2 phosphorylation, which is strictly associated with mitotic entry and progression, reduces the binding affinity of EB2 for microtubules. Expression of non-phosphorylatable EB2 induces stable kinetochore microtubule dynamics and delays formation of bipolar metaphase plates in a microtubule binding-dependent manner, and leads to aneuploidy even in unperturbed mitosis. We propose that Aurora B and CDK1 temporally regulate the binding affinity of EB2 for microtubules, thereby ensuring kinetochore microtubule dynamics, proper mitotic progression and genome stability.

  7. Unfertilized Xenopus eggs die by Bad-dependent apoptosis under the control of Cdk1 and JNK.

    Directory of Open Access Journals (Sweden)

    David Du Pasquier

    Full Text Available Ovulated eggs possess maternal apoptotic execution machinery that is inhibited for a limited time. The fertilized eggs switch off this time bomb whereas aged unfertilized eggs and parthenogenetically activated eggs fail to stop the timer and die. To investigate the nature of the molecular clock that triggers the egg decision of committing suicide, we introduce here Xenopus eggs as an in vivo system for studying the death of unfertilized eggs. We report that after ovulation, a number of eggs remains in the female body where they die by apoptosis. Similarly, ovulated unfertilized eggs recovered in the external medium die within 72 h. We showed that the death process depends on both cytochrome c release and caspase activation. The apoptotic machinery is turned on during meiotic maturation, before fertilization. The death pathway is independent of ERK but relies on activating Bad phosphorylation through the control of both kinases Cdk1 and JNK. In conclusion, the default fate of an unfertilized Xenopus egg is to die by a mitochondrial dependent apoptosis activated during meiotic maturation.

  8. Phosphorylation of the centrosomal protein, Cep169, by Cdk1 promotes its dissociation from centrosomes in mitosis.

    Science.gov (United States)

    Mori, Yusuke; Inoue, Yoko; Taniyama, Yuki; Tanaka, Sayori; Terada, Yasuhiko

    2015-12-25

    Cep169 is a centrosomal protein conserved among vertebrates. In our previous reports, we showed that mammalian Cep169 interacts and collaborates with CDK5RAP2 to regulate microtubule (MT) dynamics and stabilization. Although Cep169 is required for MT regulation, its precise cellular function remains largely elusive. Here we show that Cep169 associates with centrosomes during interphase, but dissociates from these structures from the onset of mitosis, although CDK5RAP2 (Cep215) is continuously located at the centrosomes throughout cell cycle. Interestingly, treatment with purvalanol A, a Cdk1 inhibitor, nearly completely blocked the dissociation of Cep169 from centrosomes during mitosis. In addition, mass spectrometry analyses identified 7 phosphorylated residues of Cep169 corresponding to consensus phosphorylation sequence for Cdk1. These data suggest that the dissociation of Cep169 from centrosomes is controlled by Cdk1/Cyclin B during mitosis, and that Cep169 might regulate MT dynamics of mitotic spindle.

  9. CDK1-dependent inhibition of the E3 ubiquitin ligase CRL4CDT2 ensures robust transition from S Phase to Mitosis.

    Science.gov (United States)

    Rizzardi, Lindsay F; Coleman, Kate E; Varma, Dileep; Matson, Jacob P; Oh, Seeun; Cook, Jeanette Gowen

    2015-01-02

    Replication-coupled destruction of a cohort of cell cycle proteins ensures efficient and precise genome duplication. Three proteins destroyed during replication via the CRL4(CDT2) ubiquitin E3 ligase, CDT1, p21, and SET8 (PR-SET7), are also essential or important during mitosis, making their reaccumulation after S phase a critical cell cycle event. During early and mid-S phase and during DNA repair, proliferating cell nuclear antigen (PCNA) loading onto DNA (PCNA(DNA)) triggers the interaction between CRL4(CDT2) and its substrates, resulting in their degradation. We have discovered that, beginning in late S phase, PCNA(DNA) is no longer sufficient to trigger CRL4(CDT2)-mediated degradation. A CDK1-dependent mechanism that blocks CRL4(CDT2) activity by interfering with CDT2 recruitment to chromatin actively protects CRL4(CDT2) substrates. We postulate that deliberate override of replication-coupled destruction allows anticipatory accumulation in late S phase. We further show that (as for CDT1) de novo SET8 reaccumulation is important for normal mitotic progression. In this manner, CDK1-dependent CRL4(CDT2) inactivation contributes to efficient transition from S phase to mitosis.

  10. Desmin phosphorylation by Cdk1 is required for efficient separation of desmin intermediate filaments in mitosis and detected in murine embryonic/newborn muscle and human rhabdomyosarcoma tissues.

    Science.gov (United States)

    Makihara, Hiroyuki; Inaba, Hironori; Enomoto, Atsushi; Tanaka, Hiroki; Tomono, Yasuko; Ushida, Kaori; Goto, Mitsuo; Kurita, Kenichi; Nishida, Yoshihiro; Kasahara, Kousuke; Goto, Hidemasa; Inagaki, Masaki

    2016-09-23

    Desmin is a type III intermediate filament (IF) component protein expressed specifically in muscular cells. Desmin is phosphorylated by Aurora-B and Rho-kinase specifically at the cleavage furrow from anaphase to telophase. The disturbance of this phosphorylation results in the formation of unusual long bridge-like IF structures (IF-bridge) between two post-mitotic (daughter) cells. Here, we report that desmin also serves as an excellent substrate for the other type of mitotic kinase, Cdk1. Desmin phosphorylation by Cdk1 loses its ability to form IFs in vitro. We have identified Ser6, Ser27, and Ser31 on murine desmin as phosphorylation sites for Cdk1. Using a site- and phosphorylation-state-specific antibody for Ser31 on desmin, we have demonstrated that Cdk1 phosphorylates desmin in entire cytoplasm from prometaphase to metaphase. Desmin mutations at Cdk1 sites exhibit IF-bridge phenotype, the frequency of which is significantly increased by the addition of Aurora-B and Rho-kinase site mutations to Cdk1 site mutations. In addition, Cdk1-induced desmin phosphorylation is detected in mitotic muscular cells of murine embryonic/newborn muscles and human rhabdomyosarcoma specimens. Therefore, Cdk1-induced desmin phosphorylation is required for efficient separation of desmin-IFs and generally detected in muscular mitotic cells in vivo.

  11. Cdk1, but not Cdk2, is the sole Cdk that is essential and sufficient to drive resumption of meiosis in mouse oocytes.

    Science.gov (United States)

    Adhikari, Deepak; Zheng, Wenjing; Shen, Yan; Gorre, Nagaraju; Ning, Yao; Halet, Guillaume; Kaldis, Philipp; Liu, Kui

    2012-06-01

    Mammalian oocytes are arrested at the prophase of meiosis I during fetal or postnatal development, and the meiosis is resumed by the preovulatory surge of luteinizing hormone. The in vivo functional roles of cyclin-dependent kinases (Cdks) during the resumption of meiosis in mammalian oocytes are largely unknown. Previous studies have shown that deletions of Cdk3, Cdk4 or Cdk6 in mice result in viable animals with normal oocyte maturation, indicating that these Cdks are not essential for the meiotic maturation of oocytes. In addition, conventional knockout of Cdk1 and Cdk2 leads to embryonic lethality and postnatal follicular depletion, respectively, making it impossible to study the functions of Cdk1 and Cdk2 in oocyte meiosis. In this study, we generated conditional knockout mice with oocyte-specific deletions of Cdk1 and Cdk2. We showed that the lack of Cdk1, but not of Cdk2, leads to female infertility due to a failure of the resumption of meiosis in the oocyte. Re-introduction of Cdk1 mRNA into Cdk1-null oocytes largely resumed meiosis. Thus, Cdk1 is the sole Cdk that is essential and sufficient to drive resumption of meiosis in mouse oocytes. We also found that Cdk1 maintains the phosphorylation status of protein phosphatase 1 and lamin A/C in oocytes in order for meiosis resumption to occur.

  12. Cdk1 Phosphorylates Drosophila Sas-4 to Recruit Polo to Daughter Centrioles and Convert Them to Centrosomes.

    Science.gov (United States)

    Novak, Zsofia A; Wainman, Alan; Gartenmann, Lisa; Raff, Jordan W

    2016-06-20

    Centrosomes and cilia are organized by a centriole pair comprising an older mother and a younger daughter. Centriole numbers are tightly regulated, and daughter centrioles (which assemble in S phase) cannot themselves duplicate or organize centrosomes until they have passed through mitosis. It is unclear how this mitotic "centriole conversion" is regulated, but it requires Plk1/Polo kinase. Here we show that in flies, Cdk1 phosphorylates the conserved centriole protein Sas-4 during mitosis. This creates a Polo-docking site that helps recruit Polo to daughter centrioles and is required for the subsequent recruitment of Asterless (Asl), a protein essential for centriole duplication and mitotic centrosome assembly. Point mutations in Sas-4 that prevent Cdk1 phosphorylation or Polo docking do not block centriole disengagement during mitosis, but block efficient centriole conversion and lead to embryonic lethality. These observations can explain why daughter centrioles have to pass through mitosis before they can duplicate and organize a centrosome.

  13. AZD5438, an Inhibitor of Cdk1, 2, and 9, Enhances the Radiosensitivity of Non-Small Cell Lung Carcinoma Cells

    Energy Technology Data Exchange (ETDEWEB)

    Raghavan, Pavithra; Tumati, Vasu; Yu Lan [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Chan, Norman [Departments of Medical Biophysics and Radiation Oncology, Princess Margaret Hospital, University Health Network, University of Toronto, Ontario (Canada); Tomimatsu, Nozomi [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Burma, Sandeep [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Simmons Comprehensive Cancer Center, Dallas, Texas (United States); Bristow, Robert G. [Departments of Medical Biophysics and Radiation Oncology, Princess Margaret Hospital, University Health Network, University of Toronto, Ontario (Canada); Saha, Debabrata, E-mail: debabrata.saha@utsouthwestern.edu [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Simmons Comprehensive Cancer Center, Dallas, Texas (United States)

    2012-11-15

    Purpose: Radiation therapy (RT) is one of the primary modalities for treatment of non-small cell lung cancer (NSCLC). However, due to the intrinsic radiation resistance of these tumors, many patients experience RT failure, which leads to considerable tumor progression including regional lymph node and distant metastasis. This preclinical study evaluated the efficacy of a new-generation cyclin-dependent kinase (Cdk) inhibitor, AZD5438, as a radiosensitizer in several NSCLC models that are specifically resistant to conventional fractionated RT. Methods and Materials: The combined effect of ionizing radiation and AZD5438, a highly specific inhibitor of Cdk1, 2, and 9, was determined in vitro by surviving fraction, cell cycle distribution, apoptosis, DNA double-strand break (DSB) repair, and homologous recombination (HR) assays in 3 NSCLC cell lines (A549, H1299, and H460). For in vivo studies, human xenograft animal models in athymic nude mice were used. Results: Treatment of NSCLC cells with AZD5438 significantly augmented cellular radiosensitivity (dose enhancement ratio rangeing from 1.4 to 1.75). The degree of radiosensitization by AZD5438 was greater in radioresistant cell lines (A549 and H1299). Radiosensitivity was enhanced specifically through inhibition of Cdk1, prolonged G{sub 2}-M arrest, inhibition of HR, delayed DNA DSB repair, and increased apoptosis. Combined treatment with AZD5438 and irradiation also enhanced tumor growth delay, with an enhancement factor ranging from 1.2-1.7. Conclusions: This study supports the evaluation of newer generation Cdk inhibitors, such as AZD5438, as potent radiosensitizers in NSCLC models, especially in tumors that demonstrate variable intrinsic radiation responses.

  14. Nitric oxide signals postovulatory aging-induced abortive spontaneous egg activation in rats.

    Science.gov (United States)

    Premkumar, Karuppanan V; Chaube, Shail K

    2015-07-01

    The aim of this study was to determine whether an increase of intracellular nitric oxide (NO) level signals postovulatory aging-induced abortive spontaneous egg activation (SEA) in rats. Freshly ovulated eggs (arrested at metaphase-II stage; M-II) were cultured in vitro for 3 hours to induce postovulatory egg aging. The morphological changes, inducible nitric oxide synthase (iNOS) expression, NO, cytosolic free Ca(2+), 3',5' cyclic guanosine monophosphate (cGMP), cell division cycle 25B (Cdc25B) and Wee1 levels, specific phosphorylation (pThr-14/Tyr-15) as well as total cyclin-dependent kinases-1 (Cdk1) (PSTAIRE) levels were analyzed. Postovulatory aging induced generation of NO possibly through an iNOS-mediated pathway. The increase in NO level was associated with augmented cytosolic free Ca(2+) as well as cGMP levels in aged eggs. A significant increase in Wee1 level and decrease of Cdc25B level were observed in aged eggs. An accumulation of phosphorylated Cdk1 (pThr-14/Tyr-15) level was observed in aged eggs, while total Cdk1 (PSTAIR) level remained unchanged. Our study demonstrates that generation of NO through an iNOS-mediated pathway increases cytosolic free Ca2+and cGMP levels. High levels of these signal molecules trigger the accumulation of phosphorylated Cdk1 in aged eggs. Thus, NO signals the accumulation of phosphorylated Cdk1 and induces postovulatory aging-induced abortive SEA in the rat.

  15. Survivin基因及CDK1基因联合靶向shRNA真核表达载体的构建%Constructing recombinant survivin and CDK1 tandem shRNAs pU6-M4 plasmid

    Institute of Scientific and Technical Information of China (English)

    陈淑萍; 符生苗; 周红桃; 蔡俊宏; 李成学; 王福利; 许茂轩

    2014-01-01

    目的:构建靶向Survivin基因及CDK1基因的短发夹样RNA (Short hairpin RNA,shRNA)真核表达载体。方法根据Genbank报道的Survivin序列及CDK1序列,遵循shRNA设计原则设计并合成各自靶向的Survivin、CDK1基因的shRNA寡核苷酸序列,构建pU6-shRNA-Survivin重组质粒、pU6-shRNA-CDK1重组质粒及pU6-shRNA-Survivin-U6-shRNA-CDK1双基因序列串联重组质粒,并进行限制性内切酶酶切及基因测序鉴定。结果经酶切及测序结果分析,pU6-shRNA-Survivin重组质粒、pU6-shRNA-CDK1重组质粒及pU6-shR-NA-Survivin-U6-shRNA-CDK1双基因系列串联重组质粒均成功构建。结论成功构建Survivin基因及CDK1基因联合靶向shRNA重组质粒,为进一步研究Survivin基因和CDK1基因联合干扰提供了新的方法。%Objective To construct recombinant survivin and CDK1 tandem shRNAs pU6-M4 plasmids. Methods Sequences of survivin and CDK1 and the restriction enzyme cutting sites of them were designed and synthe-sized based on the date from GeneBank. Recombinant plasmids of pU6-M4-Survivin-shRNA and pU6-M4-CDK1-shR-NA were constructed and identified. Two determined plasmids were digested by restriction endonucleases then taped by T4 DNA ligase. The ligated products were transformed into competent TH5a cells, and then the recombinant clones were identified by sequencing. Results Restriction enzyme cleave identification and sequencing proved that recombi-nant survivin and CDK1 tandem shRNAs pU6-M4 plasmids were successfully constructed. Conclusion Recombi-nant survivin and CDK1 tandem shRNAs pU6-M4 plasmids were correctly constructed.

  16. Regulation of the Candida albicans Hypha-Inducing Transcription Factor Ume6 by the CDK1 Cyclins Cln3 and Hgc1

    Science.gov (United States)

    Mendelsohn, Sigal; Pinsky, Mariel; Weissman, Ziva

    2017-01-01

    ABSTRACT The ability to switch between proliferation as yeast cells and development into hyphae is a hallmark of Candida albicans. The switch to hyphal morphogenesis depends on external inducing conditions, but its efficiency is augmented in stationary-phase cells. Ume6, a transcription factor that is itself transcriptionally induced under hypha-promoting conditions, is both necessary and sufficient for hyphal morphogenesis. We found that Ume6 is regulated posttranslationally by the cell cycle kinase Cdc28/Cdk1, which reduces Ume6 activity via different mechanisms using different cyclins. Together with the cyclin Hgc1, Cdk1 promotes degradation of Ume6 via the SCFCDC4 ubiquitin ligase. Since HGC1 is a key transcriptional target of Ume6, this results in a negative-feedback loop between Hgc1 and Ume6. In addition, we found that Cln3, a G1 cyclin that is essential for cell cycle progression and yeast proliferation, suppresses hyphal morphogenesis and that Cln3 suppresses Ume6 activity both in the heterologous Saccharomyces cerevisiae system and in C. albicans itself. This activity of Cln3 may provide the basis for the antagonistic relationship between yeast proliferation and hyphal development in C. albicans. IMPORTANCE The yeast to hypha (mold) morphogenetic switch of Candida albicans plays a role in its virulence and constitutes a diagnostic trait for this organism, the most prevalent systemic fungal pathogen in industrialized countries. It has long been known that hyphae are most efficiently induced from stationary cultures. Here, a molecular basis for this observation is provided. The G1 cyclin Cln3, an essential promoter of yeast proliferation, was found to suppress hyphal induction. Suppression of hyphal induction is achieved by inhibition of the activity of the central activator of hyphal morphogenesis, the transcription factor Ume6. Thus, levels of Cln3 control the switch between proliferation of C. albicans as individual yeast cells and development into

  17. Influence of CDK1 and CDK2 siRNA interference on tumor cell cycle and cell apoptosis%CDK1、CDK2 siRNA干扰对肿瘤细胞凋亡和细胞周期的影响

    Institute of Scientific and Technical Information of China (English)

    Hui Xiao; Wanjun Gong; Jingpeng Cao; Xiaolan Li; Deding Tao; Junbo Hu; Jianping Gong

    2009-01-01

    Objective: We investigated the influence of CDK1 and CDK2 expression inhibited by cotransfection of CDK1 and CDK2 siRNA on cell cycle and apoptosis, explored the exact role of cell cycle master regulator in tumor cell apoptosis process. Methods: The siRNA targeting the CDK1 and CDK2 genes were synthesized and simultaneously cotransfected into Hela cells by lipofectamine 2000.48 or 60 h after the cotransfection, CDK1 and CDK2 protein expressions were examined by Western blot. Cell cycle distribution was analyzed by flow cytometry. Cell apoptosis was detected by the Annexin V/PI method. The changes of the transfected cell morphological under a microscope after Wright-Giemsa Staining were studied. Results: CDK1 and CDK2 protein expression was decreased at 48 or 60 h after cotransfection. The accumulation of the G2/M and S phase population in cell cycle of the cotrensfected cells at 48 or 60 h after transfection was enhanced obviously compared with control. The ratio of apoptotic cell of cotransfected cells at 48 or 60 h after transfection was increased significantly compared with control. More binucleate or multinucleate cells among cotransfected cells were observed under the microscope. Conclu- sion: The decreased expression of CDK1 and CDK2 by cotransfection of CDK1 and CDK2 siRNA not only leads to tumor cell cycle arrest in S phase and G2/M phase, but also induces tumor cell apoptosis.

  18. Bisacylimidoselenocarbamates cause G2/M arrest associated with the modulation of CDK1 and Chk2 in human breast cancer MCF-7 cells.

    Science.gov (United States)

    Lamberto, Iranzu; Plano, Daniel; Moreno, Esther; Font, María; Palop, Juan Antonio; Sanmartín, Carmen; Encío, Ignacio

    2013-01-01

    Bisacylimidoselenocarbamate derivatives (BSC) are potent anticancer agents with a strong cytotoxic activity against different types of tumour cells. Based in phosphatidylserine exposure on the cell membranes we show that BSC treatment resulted in enhanced cell death in leukaemia CCRF-CEM cells. DNA fragmentation detection in breast adenocarcinoma MCF-7 cells showed that BSC triggered cell death is concentration and time dependent. We also show that two of these compounds, BSC 3g and 3n, cause cell-cycle arrest in the late G2/M in MCF-7 cells. Consistent with this, a reduction in CDK1 and CDK2 expression with no change in cyclin A an B1 was observed in this cell line. Activation of caspase-2 was also detected. However, the involvement of the caspase-dependent pathway in the process of cell death induced by either BSC 3g or 3n is discarded since cell death could not be prevented by pretreatment with the pancaspase inhibitor z-VAD-fmk. Moreover, since reduced levels of p21(CIP1) and Chk2 proteins but no change in p53 levels could be detected in MCF-7 cells after BSC 3g or 3n treatment our results suggest that BSC treated cells die from lethal mitosis.

  19. The cell cycle profiling-risk score based on CDK1 and 2 predicts early recurrence in node-negative, hormone receptor-positive breast cancer treated with endocrine therapy.

    Science.gov (United States)

    Kim, Seung Jin; Masuda, Norikazu; Tsukamoto, Fumine; Inaji, Hideo; Akiyama, Futoshi; Sonoo, Hiroshi; Kurebayashi, Junichi; Yoshidome, Katsuhide; Tsujimoto, Masahiko; Takei, Hiroyuki; Masuda, Shinobu; Nakamura, Seigo; Noguchi, Shinzaburo

    2014-12-28

    The Cell Cycle Profiling - Risk Score (C2P-RS) based on CDK1 and CDK2 specific activities was significantly associated with relapse in breast cancers. We evaluated the prognostic value of the C2P-RS classification using a Japanese cohort including node-negative, hormone receptor-positive breast cancers treated with adjuvant endocrine therapy alone as systemic therapy. Of 266 patients, 22 (8.3%) relapsed within 5 years after surgery. The distribution of each C2P-RS group was 71.8% in the low group, 12.0% in the intermediate group, and 16.2% in the high group. The 5-year relapse-free survival rate in the low C2P-RS group (97.3%) was significantly higher than that in the intermediate C2P-RS group (84.3%) or the high C2P-RS group (74.4%) (P < 0.001). The univariate analysis demonstrated that age, tumor size, histologic grade, and HER2 had no significant correlations with relapse but the C2P-RS classification (P < 0.001) and Ki-67 (P = 0.009) were significantly associated with relapse. Multivariate analysis showed only that the C2P-RS classification was a significant independent prognostic indicator. The C2P-RS classification might be a significant predictor of earlier recurrence in node-negative, hormone receptor-positive breast cancers treated with endocrine therapy. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Kaempferol induces autophagy through AMPK and AKT signaling molecules and causes G2/M arrest via downregulation of CDK1/cyclin B in SK-HEP-1 human hepatic cancer cells.

    Science.gov (United States)

    Huang, Wen-Wen; Tsai, Shih-Chang; Peng, Shu-Fen; Lin, Meng-Wei; Chiang, Jo-Hua; Chiu, Yu-Jen; Fushiya, Shinji; Tseng, Michael T; Yang, Jai-Sing

    2013-06-01

    Kaempferol belongs to the flavonoid family and has been used in traditional folk medicine. Here, we investigated the antitumor effects of kaempferol on cell cycle arrest and autophagic cell death in SK-HEP-1 human hepatic cancer cells. Kaempferol decreased cell viability as determined by MTT assays and induced a G2/M phase cell cycle arrest in a concentration-dependent manner. Kaempferol did not induce DNA fragmentation, apoptotic bodies or caspase-3 activity in SK-HEP-1 cells as determined by DNA gel electrophoresis, DAPI staining and caspase-3 activity assays, respectively. In contrast, kaempferol is involved in the autophagic process. Double-membrane vacuoles, lysosomal compartments, acidic vesicular organelles and cleavage of microtubule-associated protein 1 light chain 3 (LC3) were observed by transmission electron microscopy, LysoΤracker red staining, GFP-fluorescent LC3 assays and acridine orange staining, respectively. In SK-HEP-1 cells, kaempferol increased the protein levels of p-AMPK, LC3-II, Atg 5, Atg 7, Atg 12 and beclin 1 as well as inhibited the protein levels of CDK1, cyclin B, p-AKT and p-mTOR. Taken together, CDK1/cyclin B expression and the AMPK and AKT signaling pathways contributed to kaempferol-induced G2/M cell cycle arrest and autophagic cell death in SK-HEP-1 human hepatic cancer cells. These results suggest that kaempferol may be useful for long-term cancer prevention.

  1. Evaluation and comparison of 3D-QSAR CoMSIA models for CDK1, CDK5, and GSK-3 inhibition by paullones

    DEFF Research Database (Denmark)

    Kunick, Conrad; Lauenroth, Kathrin; Wieking, Karen;

    2004-01-01

    With a view to the rational design of selective GSK-3beta inhibitors, 3D-QSAR CoMSIA models were developed for the inhibition of the three serine/threonine kinases CDK1/cyclin B, CDK5/p25, and GSK-3beta by compounds from the paullone inhibitor family. The models are based on the kinase inhibition...

  2. CDK1-mediated phosphorylation of the RIIalpha regulatory subunit of PKA works as a molecular switch that promotes dissociation of RIIalpha from centrosomes at mitosis.

    Science.gov (United States)

    Carlson, C R; Witczak, O; Vossebein, L; Labbé, J C; Skålhegg, B S; Keryer, G; Herberg, F W; Collas, P; Taskén, K

    2001-09-01

    Protein kinase A regulatory subunit RIIalpha is tightly bound to centrosomal structures during interphase through interaction with the A-kinase anchoring protein AKAP450, but dissociates and redistributes from centrosomes at mitosis. The cyclin B-p34(cdc2) kinase (CDK1) has been shown to phosphorylate RIIalpha on T54 and this has been proposed to alter the subcellular localization of RIIalpha. We have made stable transfectants from an RIIalpha-deficient leukemia cell line (Reh) that expresses either wild-type or mutant RIIalpha (RIIalpha(T54E)). When expressed, RIIalpha detaches from centrosomes at mitosis and dissociates from its centrosomal location in purified nucleus-centrosome complexes by incubation with CDK1 in vitro. By contrast, centrosomal RIIalpha(T54E) is not redistributed at mitosis, remains mostly associated with centrosomes during all phases of the cell cycle and cannot be solubilized by CDK1 in vitro. Furthermore, RIIalpha is solubilized from particular cell fractions and changes affinity for AKAP450 in the presence of CDK1. D and V mutations of T54 also reduce affinity for the N-terminal RII-binding domain of AKAP450, whereas small neutral residues do not change affinity detected by surface plasmon resonance. In addition, only RIIalpha(T54E) interacts with AKAP450 in a RIPA-soluble extract from mitotic cells. Finally, microtubule repolymerization from mitotic centrosomes of the RIIalpha(T54E) transfectant is poorer and occurs at a lower frequency than that of RIIalpha transfectants. Our results suggest that T54 phosphorylation of RIIalpha by CDK1 might serve to regulate the centrosomal association of PKA during the cell cycle.

  3. Jumping the nuclear envelop barrier: Improving polyplex-mediated gene transfection efficiency by a selective CDK1 inhibitor RO-3306.

    Science.gov (United States)

    Zhou, Xuefei; Liu, Xiangrui; Zhao, Bingxiang; Liu, Xin; Zhu, Dingcheng; Qiu, Nasha; Zhou, Quan; Piao, Ying; Zhou, Zhuxian; Tang, Jianbin; Shen, Youqing

    2016-07-28

    Successful transfection of plasmid DNA (pDNA) requires intranuclear internalization of pDNA effectively and the nuclear envelope appears to be one of the critical intracellular barriers for polymer mediated pDNA delivery. Polyethylenimine (PEI), as the classic cationic polymer, compact the negatively charged pDNA tightly and make up stable polyplexes. The polyplexes are too large to enter the nuclear through nuclear pores and it is believed that the nuclear envelope breakdown in mitosis could facilitate the nuclear entry of polyplexes. To jump the nuclear envelope barrier, we used a selective and reversible CDK1 inhibitor RO-3306 to control the G2/M transition of the cell cycle and increased the proportion of mitotic cells which have disappeared nuclear envelope during transfection. Herein, we show that RO-3306 remarkably increases the transfection efficiency of PEI polyplexes through enhanced nuclear localization of PEI and pDNA. However, RO-3306 is less effective to the charge-reversal polymer poly[(2-acryloyl)ethyl(p-boronic acid benzyl)diethylammonium bromide] (B-PDEAEA) which responses to cellular stimuli and releases free pDNA in cytoplasm. Our findings not only offer new opportunities for improving non-viral based gene delivery but also provide theoretical support for the rational design of novel functional polymers for gene delivery. We also report current data showing that RO-3306 synergizes TRAIL gene induced apoptosis in cancer cells.

  4. ATF7 is stabilized during mitosis in a CDK1-dependent manner and contributes to cyclin D1 expression.

    Science.gov (United States)

    Schaeffer, Etienne; Vigneron, Marc; Sibler, Annie-Paule; Oulad-Abdelghani, Mustapha; Chatton, Bruno; Donzeau, Mariel

    2015-01-01

    The transcription factor ATF7 undergoes multiple post-translational modifications, each of which has distinct effects upon ATF7 function. Here, we show that ATF7 phosphorylation on residue Thr112 exclusively occurs during mitosis, and that ATF7 is excluded from the condensed chromatin. Both processes are CDK1/cyclin B dependent. Using a transduced neutralizing monoclonal antibody directed against the Thr112 epitope in living cells, we could demonstrate that Thr112 phosphorylation protects endogenous ATF7 protein from degradation, while it has no effect on the displacement of ATF7 from the condensed chromatin. The crucial role of Thr112 phosphorylation in stabilizing ATF7 protein during mitosis was confirmed using phospho-mimetic and phospho-deficient mutants. Finally, silencing ATF7 by CRISPR/Cas9 technology leads to a decrease of cyclin D1 protein expression levels. We propose that mitotic stabilized ATF7 protein re-localizes onto chromatin at the end of telophase and contributes to induce the cyclin D1 gene expression.

  5. Mitotic protein kinase CDK1 phosphorylation of mRNA translation regulator 4E-BP1 Ser83 may contribute to cell transformation

    Energy Technology Data Exchange (ETDEWEB)

    Velásquez, Celestino; Cheng, Erdong; Shuda, Masahiro; Lee-Oesterreich, Paula J.; Pogge von Strandmann, Lisa; Gritsenko, Marina A.; Jacobs, Jon M.; Moore, Patrick S.; Chang, Yuan

    2016-07-11

    mTOR-directed 4E-BP1 phosphorylation promotes cap-dependent translation and tumorigen-esis. During mitosis, CDK1 substitutes for mTOR and fully phosphorylates 4E-BP1 at canoni-cal as well a non-canonical S83 site resulting in a mitosis-specific hyperphosphorylated δ isoform. Colocalization studies with a phospho-S83 specific antibody indicate that 4E-BP1 S83 phosphorylation accumulates at centrosomes during prophase, peaks at metaphase, and decreases through telophase. While S83 phosphorylation of 4E-BP1 does not affect in vitro cap-dependent translation, nor eIF4G/4E-BP1 cap-binding, expression of an alanine substitution mutant 4E-BP1.S83A partially reverses rodent cell transformation induced by Merkel cell polyomavirus (MCV) small T (sT) antigen viral oncoprotein. In contrast to inhibitory mTOR 4E-BP1 phosphorylation, these findings suggest that mitotic CDK1-directed phosphorylation of δ-4E-BP1 may yield a gain-of-function, distinct from translation regulation, that may be important in tumorigenesis and mitotic centrosome function.

  6. Mitotic protein kinase CDK1 phosphorylation of mRNA translation regulator 4E-BP1 Ser83 may contribute to cell transformation.

    Science.gov (United States)

    Velásquez, Celestino; Cheng, Erdong; Shuda, Masahiro; Lee-Oesterreich, Paula J; Pogge von Strandmann, Lisa; Gritsenko, Marina A; Jacobs, Jon M; Moore, Patrick S; Chang, Yuan

    2016-07-26

    Mammalian target of rapamycin (mTOR)-directed eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) phosphorylation promotes cap-dependent translation and tumorigenesis. During mitosis, cyclin-dependent kinase 1 (CDK1) substitutes for mTOR and fully phosphorylates 4E-BP1 at canonical sites (T37, T46, S65, and T70) and the noncanonical S83 site, resulting in a mitosis-specific hyperphosphorylated δ isoform. Colocalization studies with a phospho-S83 specific antibody indicate that 4E-BP1 S83 phosphorylation accumulates at centrosomes during prophase, peaks at metaphase, and decreases through telophase. Although S83 phosphorylation of 4E-BP1 does not affect general cap-dependent translation, expression of an alanine substitution mutant 4E-BP1.S83A partially reverses rodent cell transformation induced by Merkel cell polyomavirus small T antigen viral oncoprotein. In contrast to inhibitory mTOR 4E-BP1 phosphorylation, these findings suggest that mitotic CDK1-directed phosphorylation of δ-4E-BP1 may yield a gain of function, distinct from translation regulation, that may be important in tumorigenesis and mitotic centrosome function.

  7. Inactivation of Cdk1/Cyclin B in metaphase-arrested mouse FT210 cells induces exit from mitosis without chromosome segregation or cytokinesis and allows passage through another cell cycle.

    Science.gov (United States)

    Paulson, James R

    2007-04-01

    It is well known that inactivation of Cdk1/Cyclin B is required for cells to exit mitosis. The work reported here tests the hypothesis that Cdk1/Cyclin B inactivation is not only necessary but also sufficient to induce mitotic exit and reestablishment of the interphase state. This hypothesis predicts that inactivation of Cdk1 in metaphase-arrested cells will induce the M to G1-phase transition. It is shown that when mouse FT210 cells (in which Cdk1 is temperature-sensitive) are arrested in metaphase and then shifted to their non-permissive temperature, they rapidly exit mitosis as evidenced by reassembly of interphase nuclei, decondensation of chromosomes, and dephosphorylation of histones H1 and H3. The resulting interphase cells are functionally normal as judged by their ability to progress through another cell cycle. However, they have double the normal number of chromosomes because they previously bypassed anaphase, chromosome segregation, and cytokinesis. These results, taken together with other observations in the literature, strongly suggest that in mammalian cells, inactivation of Cdk1/cyclin B is the trigger for mitotic exit and reestablishment of the interphase state.

  8. Effects of kaempferol on cell cycle status and CyclinB1,Cdk1 mRNA expressions in CNE-2 cells%山奈酚对CNE-2细胞周期及CyclinB1、Cdk1mRNA表达的影响

    Institute of Scientific and Technical Information of China (English)

    陈育华; 吴国才; 王珍; 周碧云

    2012-01-01

    Aim: To study the effects of kaempferol on cell cycle status and CyclinB1, Cdk1 mRNA expressions in CNE-2 cells. Methods:CNE-2 cells were treated with 0,20,40,60,80,and 100 μmol/L kaempferol. 24,48 and 72 h later, proliferation was determined by MTT assay;24 and 48 h later,cell cycle was detected by flow cytometry;24 h later,the expressions of CyclinBl and Cdkl mRNA were detected by RT-PCR. Results:The CNE-2 cell growth ability was inhibited by kaempferol in a time- and dose-dependent manned Fdose =385. 194,Ftime =237. 324,Finteraetion =13.757,P <0.001 );CNE-2 cells was blocked in G2/M phase ( P<0.05 );the expressions of CyclinB1 and Cdk1 mRNA decreased with the increase of kaempferol dose ( F = 95. 682,154. 871 ,P < 0. 001 ). Conclusion: Kaempferol can block CNE-2 cells in G2/M phase through decreasing the expressions of CyclinBl and Cdkl mRNA,and inhibit the cell proliferation.%目的:观察山奈酚对鼻咽癌CNE-2细胞周期分布及细胞周期素B1(CyclinB1)、细胞周期依赖性蛋白激酶1(Cdk1)表达的影响.方法:分别用0、20、40、60、80和100 μmol/L的山奈酚处理CNE-2细胞.处理24、48和72 h后,应用MTT法测定CNE-2细胞活力;处理24和48 h后用流式细胞术检测细胞周期;处理24 h后用RT-PCR技术检测细胞CyclinB1及Cdk1 mRNA的表达水平.结果:随山奈酚作用剂量的增加和作用时间的延长,CNE-2细胞活力逐渐降低(F浓度=385.194,F时间=237.324,F浓度×时间=13.757,P<0.001,细胞被阻滞于G2/M期(P<0.05);CNE-2细胞中CyclinB1和Cdk1 mRNA的表达量随山奈酚作用浓度的增加而逐渐降低(F=95.682、154.871,P<0.001).结论:山奈酚可能通过下调CNE-2细胞CyclinB1和Cdk1 mRNA的表达水平,诱导G2/M期阻滞,抑制其增殖.

  9. Androgen receptor serine 81 phosphorylation mediates chromatin binding and transcriptional activation.

    Science.gov (United States)

    Chen, Shaoyong; Gulla, Sarah; Cai, Changmeng; Balk, Steven P

    2012-03-01

    Our previous findings indicated that androgen receptor (AR) phosphorylation at serine 81 is stimulated by the mitotic cyclin-dependent kinase 1 (CDK1). In this report, we extended our previous study and confirmed that Ser-81 phosphorylation increases during mitosis, coincident with CDK1 activation. We further showed blocking cell cycle at G(1) or S phase did not disrupt androgen-induced Ser-81 phosphorylation and AR-dependent transcription, consistent with a recent report that AR was phosphorylated at Ser-81 and activated by the transcriptional CDK9. To assess the function of Ser-81 phosphorylation in prostate cancer (PCa) cells expressing endogenous AR, we developed a ligand switch strategy using a ligand-binding domain mutation (W741C) that renders AR responsive to the antagonist bicalutamide. An S81A/W741C double mutant AR stably expressed in PCa cells failed to transactivate the endogenous AR-regulated PSA or TMPRSS2 genes. ChIP showed that the S81A mutation prevented ligand-induced AR recruitment to these genes, and cellular fractionation revealed that the S81A mutation globally abrogated chromatin binding. Conversely, the AR fraction rapidly recruited to chromatin after androgen stimulation was highly enriched for Ser-81 phosphorylation. Finally, inhibition of CDK1 and CDK9 decreased AR Ser-81 phosphorylation, chromatin binding, and transcriptional activity. These findings indicate that Ser-81 phosphorylation by CDK9 stabilizes AR chromatin binding for transcription and suggest that CDK1-mediated Ser-81 phosphorylation during mitosis provides a pool of Ser-81 phosphorylation AR that can be readily recruited to chromatin for gene reactivation and may enhance AR activity in PCa.

  10. Matefin/SUN-1 Phosphorylation on Serine 43 Is Mediated by CDK-1 and Required for Its Localization to Centrosomes and Normal Mitosis in C. elegans Embryos

    Directory of Open Access Journals (Sweden)

    Noam Zuela

    2016-02-01

    Full Text Available Matefin/SUN-1 is an evolutionary conserved C. elegans inner nuclear membrane SUN-domain protein. By creating a bridge with the KASH-domain protein ZYG-12, it connects the nucleus to cytoplasmic filaments and organelles. Matefin/SUN-1 is expressed in the germline where it undergoes specific phosphorylation at its N-terminal domain, which is required for germline development and homologous chromosome pairing. The maternally deposited matefin/SUN-1 is then essential for embryonic development. Here, we show that in embryos, serine 43 of matefin/SUN-1 (S43 is phosphorylated in a CDK-1 dependent manner and is localized throughout the cell cycle mostly to centrosomes. By generating animals expressing phosphodead S43A and phosphomimetic S43E mutations, we show that phosphorylation of S43 is required to maintain centrosome integrity and function, as well as for the localization of ZYG-12 and lamin. Expression of S43E in early embryos also leads to an increase in chromatin structural changes, decreased progeny and to almost complete embryonic lethality. Down regulation of emerin further increases the occurrence of chromatin organization abnormalities, indicating possible collaborative roles for these proteins that is regulated by S43 phosphorylation. Taken together, these results support a role for phosphorylation of serine 43 in matefin/SUN-1 in mitosis.

  11. The cell cycle rallies the transcription cycle: Cdc28/Cdk1 is a cell cycle-regulated transcriptional CDK.

    Science.gov (United States)

    Chymkowitch, Pierre; Enserink, Jorrit M

    2013-01-01

    In the budding yeast Saccharomyces cerevisiae, the cyclin-dependent kinases (CDKs) Kin28, Bur1 and Ctk1 regulate basal transcription by phosphorylating the carboxyl-terminal domain (CTD) of RNA polymerase II. However, very little is known about the involvement of the cell cycle CDK Cdc28 in the transcription process. We have recently shown that, upon cell cycle entry, Cdc28 kinase activity boosts transcription of a subset of genes by directly stimulating the basal transcription machinery. Here, we discuss the biological significance of this finding and give our view of the kinase-dependent role of Cdc28 in regulation of RNA polymerase II.

  12. Optimization of the analogue-sensitive Cdc2/Cdk1 mutant by in vivo selection eliminates physiological limitations to its use in cell cycle analysis.

    Science.gov (United States)

    Aoi, Yuki; Kawashima, Shigehiro A; Simanis, Viesturs; Yamamoto, Masayuki; Sato, Masamitsu

    2014-07-01

    Analogue-sensitive (as) mutants of kinases are widely used to selectively inhibit a single kinase with few off-target effects. The analogue-sensitive mutant cdc2-as of fission yeast (Schizosaccharomyces pombe) is a powerful tool to study the cell cycle, but the strain displays meiotic defects, and is sensitive to high and low temperature even in the absence of ATP-analogue inhibitors. This has limited the use of the strain for use in these settings. Here, we used in vivo selection for intragenic suppressor mutations of cdc2-as that restore full function in the absence of ATP-analogues. The cdc2-asM17 underwent meiosis and produced viable spores to a similar degree to the wild-type strain. The suppressor mutation also rescued the sensitivity of the cdc2-as strain to high and low temperature, genotoxins and an anti-microtubule drug. We have used cdc2-asM17 to show that Cdc2 activity is required to maintain the activity of the spindle assembly checkpoint. Furthermore, we also demonstrate that maintenance of the Shugoshin Sgo1 at meiotic centromeres does not require Cdc2 activity, whereas localization of the kinase aurora does. The modified cdc2-asM17 allele can be thus used to analyse many aspects of cell-cycle-related events in fission yeast.

  13. Role for non-proteolytic control of M-phase-promoting factor activity at M-phase exit.

    Directory of Open Access Journals (Sweden)

    Vincenzo D'Angiolella

    Full Text Available M-phase Promoting Factor (MPF; the cyclin B-cdk 1 complex is activated at M-phase onset by removal of inhibitory phosphorylation of cdk1 at thr-14 and tyr-15. At M-phase exit, MPF is destroyed by ubiquitin-dependent cyclin proteolysis. Thus, control of MPF activity via inhibitory phosphorylation is believed to be particularly crucial in regulating transition into, rather than out of, M-phase. Using the in vitro cell cycle system derived form Xenopus eggs, here we show, however, that inhibitory phosphorylation of cdk1 contributes to control MPF activity during M-phase exit. By sampling extracts at very short intervals during both meiotic and mitotic exit, we found that cyclin B1-associated cdk1 underwent transient inhibitory phosphorylation at tyr-15 and that cyclin B1-cdk1 activity fell more rapidly than the cyclin B1 content. Inhibitory phosphorylation of MPF correlated with phosphorylation changes of cdc25C, the MPF phosphatase, and physical interaction of cdk1 with wee1, the MPF kinase, during M-phase exit. MPF down-regulation required Ca(++/calmodulin-dependent kinase II (CaMKII and cAMP-dependent protein kinase (PKA activities at meiosis and mitosis exit, respectively. Treatment of M-phase extracts with a mutant cyclin B1-cdk1AF complex, refractory to inhibition by phosphorylation, impaired binding of the Anaphase Promoting Complex/Cyclosome (APC/C to its co-activator Cdc20 and altered M-phase exit. Thus, timely M-phase exit requires a tight coupling of proteolysis-dependent and proteolysis-independent mechanisms of MPF inactivation.

  14. Tumor suppressor protein C53 antagonizes checkpoint kinases to promote cyclin-dependent kinase 1 activation.

    Science.gov (United States)

    Jiang, Hai; Wu, Jianchun; He, Chen; Yang, Wending; Li, Honglin

    2009-04-01

    Cyclin-dependent kinase 1 (Cdk1)/cyclin B1 complex is the driving force for mitotic entry, and its activation is tightly regulated by the G2/M checkpoint. We originally reported that a novel protein C53 (also known as Cdk5rap3 and LZAP) potentiates DNA damage-induced cell death by modulating the G2/M checkpoint. More recently, Wang et al. (2007) found that C53/LZAP may function as a tumor suppressor by way of inhibiting NF-kappaB signaling. We report here the identification of C53 protein as a novel regulator of Cdk1 activation. We found that knockdown of C53 protein causes delayed Cdk1 activation and mitotic entry. During DNA damage response, activation of checkpoint kinase 1 and 2 (Chk1 and Chk2) is partially inhibited by C53 overexpression. Intriguingly, we found that C53 interacts with Chk1 and antagonizes its function. Moreover, a portion of C53 protein is localized at the centrosome, and centrosome-targeting C53 potently promotes local Cdk1 activation. Taken together, our results strongly suggest that C53 is a novel negative regulator of checkpoint response. By counteracting Chk1, C53 promotes Cdk1 activation and mitotic entry in both unperturbed cell-cycle progression and DNA damage response.

  15. High-Activity Dealloyed Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Kongkanand, Anusorn [General Motors LLC, Pontiac, MI (United States)

    2014-09-30

    Reduction of costly Pt usage in proton exchange membrane fuel cell electrodes is one of the major challenges towards development and commercialization of fuel cell vehicles. Although few have met the initial-kinetic activity requirements in a realistic fuel cell device, no catalyst material has ever met the demanding fuel cell durability targets set by DOE. In this project, a team of 4 universities and 2 companies came together to investigate a concept that appeared promising in preliminary non-fuel cell tests then to further develop the catalyst to a mature level ready for vehicle implementation. The team consists of academia with technical leadership in their respective areas, a catalyst supplier, and a fuel cell system integrator.The tightly collaborative project enabled development of a highly active and durable catalyst with performance that significantly exceeds that of previous catalysts and meets the DOE targets for the first time (Figure 1A). The catalyst was then further evaluated in full-active-area stack in a realistic vehicle operating condition (Figure 1B). This is the first public demonstration that one can realize the performance benefit and Pt cost reduction over a conventional pure Pt catalyst in a long-term realistic PEMFC system. Furthermore, systematic analyses of a range of catalysts with different performance after fuel cell testing allowed for correlation between catalyst microstructure and its electrocatalytic activity and durability. This will in turn aid future catalyst development.

  16. A tumor suppressor C53 protein antagonizes checkpoint kinases to promote cyclin-dependent kinase 1 activation

    Science.gov (United States)

    Jiang, Hai; Wu, Jianchun; He, Chen; Yang, Wending; Li, Honglin

    2009-01-01

    Cyclin dependent kinase 1 (Cdk1)/cyclin B1 complex is the driving force for mitotic entry, and its activation is tightly regulated by the G2/M checkpoint. We originally reported that a novel protein C53 (also known as Cdk5rap3 and LZAP) potentiates DNA damage-induced cell death by modulating the G2/M checkpoint (1). More recently, Wang et al (2007) found that C53/LZAP may function as a tumor suppressor via inhibiting NF-κB signaling (2). We report here identification of C53 protein as a novel regulator of Cdk1 activation. We found that knockdown of C53 protein causes delayed Cdk1 activation and mitotic entry. During DNA damage response, activation of checkpoint kinase 1 and 2 (Chk1 and Chk2) is partially inhibited by C53 overexrepsssion. Intriguingly, we found that C53 interacts with checkpoint kinase 1 (Chk1) and antagonizes its function. Moreover, a portion of C53 protein is localized at the centrosome, and centrosome-targeting C53 potently promotes local Cdk1 activation. Taken together, our results strongly suggest that C53 is a novel negative regulator of checkpoint response. By counteracting Chk1, C53 promotes Cdk1 activation and mitotic entry in both unperturbed cell cycle progression and DNA damage response. PMID:19223857

  17. Anticancer Activity of Ramalin, a Secondary Metabolite from the Antarctic Lichen Ramalina terebrata, against Colorectal Cancer Cells

    Directory of Open Access Journals (Sweden)

    Sung-Suk Suh

    2017-08-01

    Full Text Available Colorectal cancer is a leading cause of death worldwide and occurs through the highly complex coordination of multiple cellular pathways, resulting in carcinogenesis. Recent studies have increasingly revealed that constituents of lichen extracts exhibit potent pharmaceutical activities, including anticancer activity against various cancer cells, making them promising candidates for new anticancer therapeutic drugs. The main objective of this study was to evaluate the anticancer capacities of ramalin, a secondary metabolite from the Antarctic lichen Ramalina terebrata, in the human colorectal cancer cell line HCT116. In this study, ramalin displayed concentration-dependent anticancer activity against HCT116 cells, significantly suppressing proliferation and inducing apoptosis. Furthermore, ramalin induced cell cycle arrest in the gap 2/mitosis (G2/M phase through the modulation of hallmark genes involved in the G2/M phase transition, such as tumour protein p53 (TP53, cyclin-dependent kinase inhibitor 1A (CDKN1A, cyclin-dependent kinase 1 (CDK1 and cyclin B1 (CCNB1. At both the transcriptional and translational level, ramalin caused a gradual increase in the expression of TP53 and its downstream gene CDKN1A, while decreasing the expression of CDK1 and CCNB1 in a concentration-dependent manner. In addition, ramalin significantly inhibited the migration and invasion of colorectal cancer cells in a concentration-dependent manner. Taken together, these data suggest that ramalin may be a therapeutic candidate for the targeted therapy of colorectal cancer.

  18. A mitotic phosphorylation feedback network connects Cdk1, Plk1, 53BP1, and Chk2 to inactivate the G(2)/M DNA damage checkpoint

    DEFF Research Database (Denmark)

    van Vugt, Marcel A T M; Gardino, Alexandra K; Linding, Rune;

    2010-01-01

    the DNA damage response. We demonstrate that the non-enzymatic checkpoint adaptor protein 53BP1 is an in vivo target of the cell cycle kinases Cyclin-dependent kinase-1 and Polo-like kinase-1 (Plk1). We show that Plk1 binds 53BP1 during mitosis and that this interaction is required for proper inactivation......DNA damage checkpoints arrest cell cycle progression to facilitate DNA repair. The ability to survive genotoxic insults depends not only on the initiation of cell cycle checkpoints but also on checkpoint maintenance. While activation of DNA damage checkpoints has been studied extensively, molecular...... of the DNA damage checkpoint. 53BP1 mutants that are unable to bind Plk1 fail to restart the cell cycle after ionizing radiation-mediated cell cycle arrest. Importantly, we show that Plk1 also phosphorylates the 53BP1-binding checkpoint kinase Chk2 to inactivate its FHA domain and inhibit its kinase activity...

  19. Budding yeast greatwall and endosulfines control activity and spatial regulation of PP2A(Cdc55 for timely mitotic progression.

    Directory of Open Access Journals (Sweden)

    Maria Angeles Juanes

    Full Text Available Entry into mitosis is triggered by cyclinB/Cdk1, whose activity is abruptly raised by a positive feedback loop. The Greatwall kinase phosphorylates proteins of the endosulfine family and allows them to bind and inhibit the main Cdk1-counteracting PP2A-B55 phosphatase, thereby promoting mitotic entry. In contrast to most eukaryotic systems, Cdc14 is the main Cdk1-antagonizing phosphatase in budding yeast, while the PP2A(Cdc55 phosphatase promotes, instead of preventing, mitotic entry by participating to the positive feedback loop of Cdk1 activation. Here we show that budding yeast endosulfines (Igo1 and Igo2 bind to PP2A(Cdc55 in a cell cycle-regulated manner upon Greatwall (Rim15-dependent phosphorylation. Phosphorylated Igo1 inhibits PP2A(Cdc55 activity in vitro and induces mitotic entry in Xenopus egg extracts, indicating that it bears a conserved PP2A-binding and -inhibitory activity. Surprisingly, deletion of IGO1 and IGO2 in yeast cells leads to a decrease in PP2A phosphatase activity, suggesting that endosulfines act also as positive regulators of PP2A in yeast. Consistently, RIM15 and IGO1/2 promote, like PP2A(Cdc55, timely entry into mitosis under temperature-stress, owing to the accumulation of Tyr-phosphorylated Cdk1. In addition, they contribute to the nuclear export of PP2A(Cdc55, which has recently been proposed to promote mitotic entry. Altogether, our data indicate that Igo proteins participate in the positive feedback loop for Cdk1 activation. We conclude that Greatwall, endosulfines, and PP2A are part of a regulatory module that has been conserved during evolution irrespective of PP2A function in the control of mitosis. However, this conserved module is adapted to account for differences in the regulation of mitotic entry in different organisms.

  20. Tumor suppressor protein C53 antagonizes checkpoint kinases to promote cyclin-dependent kinase 1 activation

    Institute of Scientific and Technical Information of China (English)

    Hai Jiang; Jianchun Wu; Chen He; Wending Yang; Honglin Li

    2009-01-01

    Cyclin-dependent kinase 1 (Cdk1)/cyclin B1 complex is the driving force for mitotic entry, and its activation is tightly regulated by the G2/M checkpoint. We originally reported that a novel protein C53 (also known as Cdk5rap3 and LZAP) potentiates DNA damage-induced cell death by modulating the G2/M checkpoint. More recently, Wang et al. (2007) found that C53/LZAP may function as a tumor suppressor by way of inhibiting NF-kB signaling. We report here the identification of C53 protein as a novel regulator of Cdk1 activation. We found that knockdown of C53 protein causes delayed Cdkl activation and mitotic entry. During DNA damage response, activation of checkpoint kinase 1 and 2 (Chk1 and Chk2) is partially inhibited by C53 overexpression. Intriguingly, we found that C53 interacts with Chkl and antagonizes its function. Moreover, a portion of C53 protein is localized at the centrosome, and centrosome-targeting C53 potently promotes local Cdk1 activation. Taken together, our results strongly suggest that C53 is a novel negative regulator of checkpoint response. By counteracting Chk1, C53 promotes Cdk1 activation and mitotic entry in both unperturbed cell-cycle progression and DNA damage response.

  1. Planning High-Risk High-Reward Activities.

    NARCIS (Netherlands)

    Casault, Sébastien

    2014-01-01

    This body of work addresses a gap in financial and economic theories related to assets that are typically associated with high uncertainty. Specifically, this thesis provides some foundational work towards a new way to quantify and explain how high-risk high-reward activities, such as exploration,

  2. High effective silica fume alkali activator

    Indian Academy of Sciences (India)

    Vladimír Živica

    2004-04-01

    Growing demands on the engineering properties of cement based materials and the urgency to decrease unsuitable ecologic impact of Portland cement manufacturing represent significant motivation for the development of new cement corresponding to these aspects. One category represents prospective alkali activated cements. A significant factor influencing their properties is alkali activator used. In this paper we present a new high effective alkali activator prepared from silica fume and its effectiveness. According to the results obtained this activator seems to be more effective than currently used activators like natrium hydroxide, natrium carbonate, and water glass.

  3. Enclosure for handling high activity materials

    Energy Technology Data Exchange (ETDEWEB)

    Jimeno de Osso, F.

    1977-07-01

    One of the most important problems that are met at the laboratories producing and handling radioisotopes is that of designing, building and operating enclosures suitable for the safe handling of active substances. With this purpose in mind, an enclosure has been designed and built for handling moderately high activities under a shielding made of 150 mm thick lead. In this report a description is given of those aspects that may be of interest to people working in this field. (Author)

  4. High-activity liquid packaging design criteria

    Energy Technology Data Exchange (ETDEWEB)

    1994-05-01

    In recent studies, it has been acknowledged that there is an emerging need for packaging to transport high-activity liquid off the Hanford Site to support characterization and process development activities of liquid waste stored in underground tanks. These studies have dealt with specimen testing needs primarily at the Hanford Site; however, similar needs appear to be developing at other US Department of Energy (DOE) sites. The need to ship single and multiple specimens to offsite laboratories is anticipated because it is predicted that onsite laboratories will be overwhelmed by an increasing number and size (volume) of samples. Potentially, the specimen size could range from 250 mL to greater than 50 L. Presently, no certified Type-B packagings are available for transport of high-activity liquid radioactive specimens in sizes to support Site missions.

  5. High activity carbon sorbents for mercury capture

    Energy Technology Data Exchange (ETDEWEB)

    George G. Stavropoulos; Irene S. Diamantopoulou; George E. Skodras; George P. Sakellaropoulos [Aristotle University of Thessaloniki, Thessaloniki (Greece). Chemical Process Engineering Laboratory

    2006-07-01

    High efficiency activated carbons have been prepared for removing mercury from gas streams. Starting materials used were petroleum coke, lignite, charcoal and olive seed waste, and were chemically activated with KOH. Produced adsorbents were primarily characterized for their porosity by N{sub 2} adsorption at 77K. Their mercury retention capacity was characterized based on the breakthrough curves. Compared with typical commercial carbons, they have exhibited considerably enhanced mercury adsorption capacity. An attempt has been made to correlate mercury entrapment and pore structure. It has been shown that physical surface area is increased during activation in contrast to the mercury adsorption capacity that initially increases and tends to decrease at latter stages. Desorption of active sites may be responsible for this behavior. 10 refs., 3 figs., 1 tab.

  6. Production of high specific activity silicon-32

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, D.R. [Los Alamos National Lab., NM (United States); Brzezinski, M.A. [Univ. of California, Santa Barbara, CA (United States). Marine Biotechnology Center

    1998-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development Project (LDRD) at Los Alamos National Laboratory (LANL). There were two primary objectives for the work performed under this project. The first was to take advantage of capabilities and facilities at Los Alamos to produce the radionuclide {sup 32}Si in unusually high specific activity. The second was to combine the radioanalytical expertise at Los Alamos with the expertise at the University of California to develop methods for the application of {sup 32}Si in biological oceanographic research related to global climate modeling. The first objective was met by developing targetry for proton spallation production of {sup 32}Si in KCl targets and chemistry for its recovery in very high specific activity. The second objective was met by developing a validated field-useable, radioanalytical technique, based upon gas-flow proportional counting, to measure the dynamics of silicon uptake by naturally occurring diatoms.

  7. Active vibration isolation of high precision machines

    CERN Document Server

    Collette, C; Artoos, K; Hauviller, C

    2010-01-01

    This paper provides a review of active control strategies used to isolate high precisionmachines (e.g. telescopes, particle colliders, interferometers, lithography machines or atomic force microscopes) from external disturbances. The objective of this review is to provide tools to develop the best strategy for a given application. Firstly, the main strategies are presented and compared, using single degree of freedom models. Secondly, the case of huge structures constituted of a large number of elements, like particle colliders or segmented telescopes, is considered.

  8. High Energy Activation Data Library (HEAD-2009)

    CERN Document Server

    Korovin, Yury A; Konobeyev, Alexander Yu; Stankovskiy, Alexey Yu; Mashnik, Stepan G

    2010-01-01

    A proton activation data library for 682 nuclides from 1-H to 210-Po in the energy range from 150 MeV up to 1 GeV was developed. To calculate proton activation data, the MCNPX 2.6.0 and CASCADE/INPE codes were chosen. Different intranuclear cascade, preequilibrium, and equilibrium nuclear reaction models and their combinations were used. The optimum calculation models have been chosen on the basis of statistical correlations for calculated and experimental proton data taken from the EXFOR library of experimental nuclear data. All the data are written in ENDF-6 format. The library is called HEPAD-2008 (High-Energy Proton Activation Data). A revision of IEAF-2005 neutron activation data library has been performed: A set of nuclides for which the cross-section data can be (and were) updated using more modern and improved models is specified, and the corresponding calculations have been made in the present work. The new version of the library is called IEAF-2009. The HEPAD-2008 and IEAF-2009 are merged to the fin...

  9. Concrete with Highly Active Rice Husk Ash

    Institute of Scientific and Technical Information of China (English)

    FENG Qing-ge; LIN Qing-yu; YU Qi-jun; ZHAO San-ying; YANG Lu-feng; Shuichi Sugita

    2004-01-01

    The overall aim was to investigate the effect of highly active rice husk ash (RHA) produced by an industrial furnace on some properties of concrete. The strength, pore volume and pore distribution of concrete and the Ca(OH)2 content in concrete were investigated by JIS A 1108 (Method of test for compressive strength of concrete), a mercury instrument porosimeter, and the thermogravimetric analysis, respectively. The results show that,with RHA replacement of cement,the compressive strength of concrete is increased evidently;the average pore radius of concrete is greatly decreased, especially the portion of the pores greater than 20nm in radius is decreased while the amount of smaller pores is increased, and the more the RHA replacement, the less the amount of Ca(OH)2 in concrete. The latter two results are the main reasons for the strength enhancement of concrete.

  10. High-Throughput Analysis of Enzyme Activities

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Guoxin [Iowa State Univ., Ames, IA (United States)

    2007-01-01

    High-throughput screening (HTS) techniques have been applied to many research fields nowadays. Robot microarray printing technique and automation microtiter handling technique allows HTS performing in both heterogeneous and homogeneous formats, with minimal sample required for each assay element. In this dissertation, new HTS techniques for enzyme activity analysis were developed. First, patterns of immobilized enzyme on nylon screen were detected by multiplexed capillary system. The imaging resolution is limited by the outer diameter of the capillaries. In order to get finer images, capillaries with smaller outer diameters can be used to form the imaging probe. Application of capillary electrophoresis allows separation of the product from the substrate in the reaction mixture, so that the product doesn't have to have different optical properties with the substrate. UV absorption detection allows almost universal detection for organic molecules. Thus, no modifications of either the substrate or the product molecules are necessary. This technique has the potential to be used in screening of local distribution variations of specific bio-molecules in a tissue or in screening of multiple immobilized catalysts. Another high-throughput screening technique is developed by directly monitoring the light intensity of the immobilized-catalyst surface using a scientific charge-coupled device (CCD). Briefly, the surface of enzyme microarray is focused onto a scientific CCD using an objective lens. By carefully choosing the detection wavelength, generation of product on an enzyme spot can be seen by the CCD. Analyzing the light intensity change over time on an enzyme spot can give information of reaction rate. The same microarray can be used for many times. Thus, high-throughput kinetic studies of hundreds of catalytic reactions are made possible. At last, we studied the fluorescence emission spectra of ADP and obtained the detection limits for ADP under three different

  11. Metabolic Activity of Bacteria at High Pressure

    Science.gov (United States)

    Picard, A.; Daniel, I.; Oger, P.

    2008-12-01

    Over the last 20 years, there has been increasing evidence for the presence of a large number of microbes in the oceanic subsurface. Such a habitat has a very low energy input because it is deprived of light. A few meters below the sediment surface, conditions are already anoxic in most cases, sulfate reduction and/or methanogenesis becoming thus the primary respiratory reactions of organic matter. Neither the fate of methanogenesis, nor the fate of Dissimilatory Metal-Reduction (DMR) has been investigated so far as a function of pressure. For this reason, we measured experimentally the pressure limits of microbial anaerobic energetic metabolism. In practice, we measured in situ the kinetics of selenite respiration by the bacterial model Shewanella oneidensis MR-1 under high hydrostatic pressure (HHP) between 0 and 150 MPa at 30°C. MR-1 stationary-phase cells were used in Luria-Bertani (LB) medium amended with lactate as an additional electron donor and sodium selenite as an electron acceptor. In situ measurements were performed by X- ray Absorption Near-Edge Structure (XANES) spectroscopy in both a diamond-anvil cell and an autoclave. A red precipitate of amorphous Se(0) was virtually observed at any pressure to 150 MPa. A progressive reduction of selenite Se(IV) into selenium Se(0) was also observed in the evolution of XANES spectra with time. All kinetics between 0.1 and 150 MPa can be adjusted to a first order kinetic law. MR-1 respires all available selenite up to 60 MPa. Above 60 MPa, the respiration yield decreases linearly as a function of pressure and reaches 0 at 155 ±5 MPa. This indicates that selenite respiration by Shewanella oneidensis MR-1 stops at about 155 MPa, whereas its growth is arrested at 50 MPa. Hence, the present results show that the respiration of selenium by the strain MR-1 occurs efficiently up to 60 MPa and 30°C, i.e. from the surface of a continental sediment to an equivalent depth of about 2 km, or beneath a 5-km water column and

  12. Highly active thermally stable nanoporous gold catalyst

    Science.gov (United States)

    Biener, Juergen; Wittstock, Arne; Biener, Monika M.; Bagge-Hansen, Michael; Baeumer, Marcus; Wichmann, Andre; Neuman, Bjoern

    2016-12-20

    In one embodiment, a system includes a nanoporous gold structure and a plurality of oxide particles deposited on the nanoporous gold structure; the oxide particles are characterized by a crystalline phase. In another embodiment, a method includes depositing oxide nanoparticles on a nanoporous gold support to form an active structure and functionalizing the deposited oxide nanoparticles.

  13. Highly active thermally stable nanoporous gold catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Biener, Juergen; Wittstock, Arne; Biener, Monika M.; Bagge-Hansen, Michael; Baeumer, Marcus; Wichmann, Andre; Neuman, Bjoern

    2016-12-20

    In one embodiment, a system includes a nanoporous gold structure and a plurality of oxide particles deposited on the nanoporous gold structure; the oxide particles are characterized by a crystalline phase. In another embodiment, a method includes depositing oxide nanoparticles on a nanoporous gold support to form an active structure and functionalizing the deposited oxide nanoparticles.

  14. Active control system for high speed windmills

    Science.gov (United States)

    Avery, D.E.

    1988-01-12

    A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed. 4 figs.

  15. Cdk and APC activities limit the spindle-stabilizing function of Fin1 to anaphase.

    Science.gov (United States)

    Woodbury, Erika L; Morgan, David O

    2007-01-01

    The fidelity of chromosome segregation depends on proper regulation of mitotic spindle behaviour. In anaphase, spindle stability is promoted by the dephosphorylation of cyclin-dependent kinase (Cdk) substrates, which results from Cdk inactivation and phosphatase activation. Few of the critical Cdk targets have been identified. Here, we identify the budding-yeast protein Fin1 (ref. 7) as a spindle-stabilizing protein whose activity is strictly limited to anaphase by changes in its phosphorylation state and rate of degradation. Phosphorylation of Fin1 from S phase to metaphase, by the cyclin-dependent kinase Clb5-Cdk1, inhibits Fin1 association with the spindle. In anaphase, when Clb5-Cdk1 is inactivated, Fin1 is dephosphorylated by the phosphatase Cdc14. Fin1 dephosphorylation targets it to the poles and microtubules of the elongating spindle, where it contributes to spindle integrity. A non-phosphorylatable Fin1 mutant localizes to the spindle before anaphase and impairs efficient chromosome segregation. As cells complete mitosis and disassemble the spindle, the ubiqutin ligase APC(Cdh1) targets Fin1 for destruction. Our studies illustrate how phosphorylation-dependent changes in the behaviour of Cdk1 substrates influence complex mitotic processes.

  16. Catalytically highly active top gold atom on palladium nanocluster.

    Science.gov (United States)

    Zhang, Haijun; Watanabe, Tatsuya; Okumura, Mitsutaka; Haruta, Masatake; Toshima, Naoki

    2011-10-23

    Catalysis using gold is emerging as an important field of research in connection with 'green' chemistry. Several hypotheses have been presented to explain the markedly high activities of Au catalysts. So far, the origin of the catalytic activities of supported Au catalysts can be assigned to the perimeter interfaces between Au nanoclusters and the support. However, the genesis of the catalytic activities of colloidal Au-based bimetallic nanoclusters is unclear. Moreover, it is still a challenge to synthesize Au-based colloidal catalysts with high activity. Here we now present the 'crown-jewel' concept (Supplementary Fig. S1) for preparation of catalytically highly Au-based colloidal catalysts. Au-Pd colloidal catalysts containing an abundance of top (vertex or corner) Au atoms were synthesized according to the strategy on a large scale. Our results indicate that the genesis of the high activity of the catalysts could be ascribed to the presence of negatively charged top Au atoms.

  17. Identification of highly active flocculant proteins in bovine blood.

    Science.gov (United States)

    Piazza, George J; Nuñez, Alberto; Garcia, Rafael A

    2012-03-01

    Synthetic polymeric flocculants are used extensively for wastewater remediation, soil stabilization, and reduction in water leakage from unlined canals. Sources of highly active, inexpensive, renewable flocculants are needed to replace synthetic flocculants. High kaolin flocculant activity was documented for bovine blood (BB) and blood plasma with several anticoagulant treatments. BB serum also had high flocculant activity. To address the hypothesis that some blood proteins have strong flocculating activity, the BB proteins were separated by SEC. Then, the major proteins of the flocculant-active fractions were separated by SDS-PAGE. Identity of the major protein components was determined by tryptic digestion and peptide analysis by MALDI TOF MS. The sequence of selected peptides was confirmed using TOF/TOF-MS/MS fragmentation. Hemoglobin dimer (subunits α and β) was identified as the major protein component of the active fraction in BB; its high flocculation activity was confirmed by testing a commercial sample of hemoglobin. In the same manner, three proteins from blood plasma (fibrinogen, γ-globulin, α-2-macroglobulin) were found to be highly active flocculants, but bovine serum albumin, α-globulin, and β-globulin were not flocculants. On a mass basis, hemoglobin, γ-globulin, α-2-macroglobulin were as effective as anionic polyacrylamide (PAM), a widely used synthetic flocculant. The blood proteins acted faster than PAM, and unlike PAM, the blood proteins flocculants did not require calcium salts for their activity.

  18. Social capital and physical activity among Croatian high school students.

    Science.gov (United States)

    Novak, D; Doubova, S V; Kawachi, I

    2016-06-01

    To examine factors associated with regular physical activity in Croatian adolescents. A cross-sectional survey among high school students was carried out in the 2013/14 school year. A survey was conducted among 33 high schools in Zagreb City, Croatia. Participants were students aged 17-18 years. The dependent variables were regular moderate to vigorous physical activity (MVPA) and overall physical activity measured by the short version of International Physical Activity Questionnaire and defined as 60 min or more of daily physical activity. The independent variables included family, neighborhood, and high school social capital. Other study covariates included: socio-economic status, self-rated health, psychological distress and nutritional status. The associations between physical activity and social capital variables were assessed separately for boys and girls through multiple logistic regression and inverse probability weighting in order to correct for missing data bias. A total of 1689 boys and 1739 girls responded to the survey. A higher percentage of boys reported performing regular vigorous and moderate physical activity (59.4%) and overall physical activity (83.4%), comparing with the girls (35.4% and 70%, respectively). For boys, high family social capital and high informal social control were associated with increased odds of regular MVPA (1.49, 95%CI: 1.18 - 1.90 and 1.26, 95%CI: 1.02 - 1.56, respectively), compared to those with low social capital. For girls, high informal social control was associated with regular overall physical activity (OR 1.38, 95% CI: 1.09 - 1.76). High social capital is associated with regular MVPA in boys and regular overall activity in girls. Intervention and policies that leverage community social capital might serve as an avenue for promotion of physical activity in youth. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  19. High disease activity is related to low levels of physical activity in patients with ankylosing spondylitis.

    Science.gov (United States)

    Fongen, Camilla; Halvorsen, Silje; Dagfinrud, Hanne

    2013-12-01

    This study aims to compare physical activity (PA) level and exercise habits in patients with ankylosing spondylitis (AS) who have high disease activity with those who have low disease activity and, further, to compare both groups with population controls. Cross-sectional study design was used. The participants include 149 patients (mean age 49.3 (SD 11.1), 61% men, 54% high disease activity) and 133 controls (mean age 52.7 (SD11.3), 58% men). PA was reported with the International PA Questionnaire-Long and results were presented as weekly energy expenditure (metabolic equivalent, MET) in different intensities, domains, and proportion reaching health enhancing physical activity (HEPA). Types of PA were registered in a structured interview. The AS Disease Activity Score was used to assess patients' disease activity. Patients with high disease activity reported significantly lower total weekly energy expenditure (MET) than patients with low disease activity and controls (p = 0.02, p = 0.01, respectively) and lower amounts of walking (p < 0.01, p = 0.02, respectively) and vigorous activity (p = 0.06, p = 0.06, respectively). Only 41% of the patients with high disease activity reached HEPA compared to 61% of the patients with low disease activity (p = 0.02). Patients in general participated less in leisure PA performed outdoor and with higher intensities (MET ≥ 6) than controls.AS patients with high disease activity had lower weekly energy expenditure in PA than patients with low disease activity and controls, and were less likely to reach HEPA than patients with low disease activity. For optimal management, health professionals should focus on physical activity in their consultations with AS patients, especially those with high disease activity.

  20. High Resolution Screening of biologically active compounds and metabolites

    NARCIS (Netherlands)

    Kool, J.

    2007-01-01

    High Resolution Screening of biologically active compounds and metabolites Jeroen Kool Biotransformation enzymes play a crucial role in the metabolism of both endogenous compounds and xenobiotics. Usually, the detoxication of these compounds by biotransformation enzymes results in harmless metab

  1. Murine erythrocytes contain high levels of lysophospholipase activity

    NARCIS (Netherlands)

    Kamp, J.A.F. op den; Roelofsen, B.; Sanderink, G.; Middelkoop, E.; Hamer, R.

    1984-01-01

    Murine erythrocytes were found to be unique in the high levels of lysophospholipase activity in the cytosol of these cells. The specific activity of the enzyme in the cytosol of the murine cells is 10-times higher than in the cytosol of rabbit erythrocytes and approximately three orders of magnitude

  2. The physical activity climate in Minnesota middle and high schools.

    Science.gov (United States)

    Samuelson, Anne; Lytle, Leslie; Pasch, Keryn; Farbakhsh, Kian; Moe, Stacey; Sirard, John Ronald

    2010-11-01

    This article describes policies, practices, and facilities that form the physical activity climate in Minneapolis/St. Paul, Minnesota metro area middle and high schools and examines how the physical activity climate varies by school characteristics, including public/private, school location and grade level. Surveys examining school physical activity practices, policies and environment were administered to principals and physical education department heads from 115 middle and high schools participating in the Transdisciplinary Research on Energetics and Cancer-Identifying Determinants of Eating and Activity (TREC-IDEA) study. While some supportive practices were highly prevalent in the schools studied (such as prohibiting substitution of other classes for physical education); other practices were less common (such as providing opportunity for intramural (noncompetitive) sports). Public schools vs. private schools and schools with a larger school enrollment were more likely to have a school climate supportive of physical activity. Although schools reported elements of positive physical activity climates, discrepancies exist by school characteristics. Of note, public schools were more than twice as likely as private schools to have supportive physical activity environments. Establishing more consistent physical activity expectations and funding at the state and national level is necessary to increase regular school physical activity.

  3. 78 FR 70567 - Nationwide Use of High Frequency and Ultra High Frequency Active SONAR Technology; Final...

    Science.gov (United States)

    2013-11-26

    ...] Nationwide Use of High Frequency and Ultra High Frequency Active SONAR Technology; Final Programmatic... Programmatic Environmental Assessment (PEA) for the Nationwide Use of High Frequency (HF) and Ultra High Frequency (UHF) Sound Navigation and Ranging (SONAR) Technology and Finding of No Significant Impact (FONSI...

  4. Kinase activity ranking using phosphoproteomics data (KARP) quantifies the contribution of protein kinases to the regulation of cell viability.

    Science.gov (United States)

    Wilkes, Edmund H; Casado, Pedro; Rajeeve, Vinothini; Cutillas, Pedro R

    2017-09-01

    Cell survival is regulated by a signaling network driven by the activity of protein kinases; however, determining the contribution that each kinase in the network makes to such regulation remains challenging. Here, we report a computational approach that uses mass spectrometry-based phosphoproteomics data to rank protein kinases based on their contribution to cell regulation. We found that the scores returned by this algorithm, which we have termed kinase activity ranking using phosphoproteomics data (KARP), were a quantitative measure of the contribution that individual kinases make to the signaling output. Application of KARP to the analysis of eight hematological cell lines revealed that cyclin-dependent kinase (CDK) 1/2, casein kinase (CK) 2, extracellular signal-related kinase (ERK), and p21-activated kinase (PAK) were the most frequently highly ranked kinases in these cell models. The patterns of kinase activation were cell-line specific yet showed a significant association with cell viability as a function of kinase inhibitor treatment. Thus, our study exemplifies KARP as an untargeted approach to empirically and systematically identify regulatory kinases within signaling networks. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Experimental conditions affecting functional comparison of highly active glutathione transferases.

    Science.gov (United States)

    Fedulova, Natalia; Mannervik, Bengt

    2011-06-01

    Glutathione transferases (GSTs, EC 2.5.1.18) possess multiple functions and have potential applications in biotechnology. Direct evidence of underestimation of activity of human GST A3-3 and porcine GST A2-2 measured at submicromolar enzyme concentrations is reported here for the first time. The combination of time-dependent and enzyme concentration-dependent loss of activity and the choice of the organic solvent for substrates were found to cause irreproducibility of activity measurements of GSTs. These effects contribute to high variability of activity values of porcine GST A2-2 and human Alpha-class GSTs reported in the literature. Adsorption of GSTs to surfaces was found to be the main explanation of the observed phenomena. Several approaches to improved functional comparison of highly active GSTs are proposed.

  6. High Power VCSEL Device with Periodic Gain Active Region

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    High power vertical cavity surface emitting lasers(VCSEKLs) with large aperture have been fabricated through improving passivation, lateral oxidation and heat dissipation techniques. Different from conventional three quantum well structures, a periodic gain active region with nine quantum wells was incorporated into the VCSEL structure, with which high efficiency and high power operation were expected. The nine quantum wells were divided into three groups with each of them located at the antinodes of the ca...

  7. Super-SERS-active and highly effective antimicrobial Ag nanodendrites

    Science.gov (United States)

    Li, H. B.; Liu, P.; Liang, Y.; Xiao, J.; Yang, G. W.

    2012-07-01

    We have developed simple and green electrochemistry to synthesize Ag nanostructures with high purity, good crystallinity and smooth surface for applications as super-SERS (surface-enhanced Raman scattering), SERS-active substrates and with highly effective antimicrobial activities. This synthesis takes place in a clean and slow reaction environment without any chemical additives, which ensures an ultrahigh active surface of the as-synthesized Ag nanostructures owing to their purity, good crystallinity and smooth morphology. Using this method, we synthesized nearly perfect Ag nanodendrites (NDs), which exhibit super-SERS sensitivity when they are used to detect the SERS spectra of rhodamine 6G at concentrations as low as 5 × 10-16 M, and have an ultrahigh electromagnetic (EM) enhancement factor of the order of 1013, breaking through the theoretical limit of EM enhancement. Meanwhile, the as-synthesized Ag NDs possess highly effective antimicrobial activities for Escherichia coli, Candida albicans and Staphylococcus aureus, which are over 10 times that of silver nanoparticles. Additionally, the basic physics and chemistry involved in the fabrication of Ag nanostructures are pursued. These investigations show that silver nanostructures with highly active surfaces can make the most of Ag nanostructures functioning as super-SERS-active substrates and multiple antibiotics.

  8. School day segmented physical activity patterns of high and low active children

    Science.gov (United States)

    2012-01-01

    Background Variability exists in children’s activity patterns due to the association with environmental, social, demographic, and inter-individual factors. This study described accelerometer assessed physical activity patterns of high and low active children during segmented school week days whilst controlling for potential correlates. Methods Two hundred and twenty-three children (mean age: 10.7 ± 0.3 yrs, 55.6% girls, 18.9% overweight/obese) from 8 north-west England primary schools wore ActiGraph GT1M accelerometers for 7 consecutive days during autumn of 2009. ActiGraph counts were converted to minutes of moderate (MPA), vigorous (VPA) and moderate-to-vigorous (MVPA) physical activity. Children were classified as high active (HIGH) or low active (LOW) depending on the percentage of week days they accumulated at least 60 minutes of MVPA. Minutes spent in MPA and VPA were calculated for school time and non-school time and for five discrete school day segments (before-school, class time, recess, lunchtime, and after-school). Data were analysed using multi-level modelling. Results The HIGH group spent significantly longer in MPA and/or VPA before-school, during class time, lunchtime, and after-school (P children, playground area per student, and temperature, depending on the segment analysed. The additive effect of the segment differences was that the HIGH group accumulated 12.5 minutes per day more MVPA than the LOW group. Conclusions HIGH active children achieved significantly more MPA and VPA than LOW active during four of the five segments of the school day when analyses were adjusted for potential correlates. Physical activity promotion strategies targeting low active children during discretionary physical activity segments of the day, and particularly via structured afterschool physical activity programs may be beneficial. PMID:22672654

  9. School day segmented physical activity patterns of high and low active children.

    Science.gov (United States)

    Fairclough, Stuart J; Beighle, Aaron; Erwin, Heather; Ridgers, Nicola D

    2012-06-06

    Variability exists in children's activity patterns due to the association with environmental, social, demographic, and inter-individual factors. This study described accelerometer assessed physical activity patterns of high and low active children during segmented school week days whilst controlling for potential correlates. Two hundred and twenty-three children (mean age: 10.7 ± 0.3 yrs, 55.6% girls, 18.9% overweight/obese) from 8 north-west England primary schools wore ActiGraph GT1M accelerometers for 7 consecutive days during autumn of 2009. ActiGraph counts were converted to minutes of moderate (MPA), vigorous (VPA) and moderate-to-vigorous (MVPA) physical activity. Children were classified as high active (HIGH) or low active (LOW) depending on the percentage of week days they accumulated at least 60 minutes of MVPA. Minutes spent in MPA and VPA were calculated for school time and non-school time and for five discrete school day segments (before-school, class time, recess, lunchtime, and after-school). Data were analysed using multi-level modelling. The HIGH group spent significantly longer in MPA and/or VPA before-school, during class time, lunchtime, and after-school (P children, playground area per student, and temperature, depending on the segment analysed.The additive effect of the segment differences was that the HIGH group accumulated 12.5 minutes per day more MVPA than the LOW group. HIGH active children achieved significantly more MPA and VPA than LOW active during four of the five segments of the school day when analyses were adjusted for potential correlates. Physical activity promotion strategies targeting low active children during discretionary physical activity segments of the day, and particularly via structured afterschool physical activity programs may be beneficial.

  10. School day segmented physical activity patterns of high and low active children

    Directory of Open Access Journals (Sweden)

    Fairclough Stuart J

    2012-06-01

    Full Text Available Abstract Background Variability exists in children’s activity patterns due to the association with environmental, social, demographic, and inter-individual factors. This study described accelerometer assessed physical activity patterns of high and low active children during segmented school week days whilst controlling for potential correlates. Methods Two hundred and twenty-three children (mean age: 10.7 ± 0.3 yrs, 55.6% girls, 18.9% overweight/obese from 8 north-west England primary schools wore ActiGraph GT1M accelerometers for 7 consecutive days during autumn of 2009. ActiGraph counts were converted to minutes of moderate (MPA, vigorous (VPA and moderate-to-vigorous (MVPA physical activity. Children were classified as high active (HIGH or low active (LOW depending on the percentage of week days they accumulated at least 60 minutes of MVPA. Minutes spent in MPA and VPA were calculated for school time and non-school time and for five discrete school day segments (before-school, class time, recess, lunchtime, and after-school. Data were analysed using multi-level modelling. Results The HIGH group spent significantly longer in MPA and/or VPA before-school, during class time, lunchtime, and after-school (P P  The additive effect of the segment differences was that the HIGH group accumulated 12.5 minutes per day more MVPA than the LOW group. Conclusions HIGH active children achieved significantly more MPA and VPA than LOW active during four of the five segments of the school day when analyses were adjusted for potential correlates. Physical activity promotion strategies targeting low active children during discretionary physical activity segments of the day, and particularly via structured afterschool physical activity programs may be beneficial.

  11. Recommendations of activity restriction in high-risk pregnancy scenarios

    DEFF Research Database (Denmark)

    Bendix, Jane; Hegaard, Hanne Kristine; Bergholt, Thomas;

    2015-01-01

    obstetricians and midwives prescribe activity restriction in most high-risk pregnancies. The degree of activity restriction and the presumed effect vary between clinicians. This may reflect different attitudes and lack of guidelines based on clinical studies of a possible benefit of activity restriction....... to the obstetricians, the midwives also reported that they expected the recommendation to be more effective. Most midwives and obstetricians reported that they thought strict activity restriction was associated with severe or moderate adverse effect, and recommended antithrombotic prophylaxis. Conclusions: Danish......Abstract Aims: To describe specific recommendations of activity restriction, place of care, expected beneficial and adverse effects, and recommended antithrombotic prophylaxis in nine clinical scenarios. Methods: A national survey. All members of the Danish Society of Obstetrics and Gynaecology...

  12. High lightning activity in maritime clouds near Mexico

    Directory of Open Access Journals (Sweden)

    B. Kucienska

    2012-01-01

    Full Text Available Lightning activity detected by the World Wide Lightning Location Network (WWLLN over oceanic regions adjacent to Mexico is often as high as that observed over the continent. In order to explore the possible cause of the observed high flash density over those regions, the relationships between lightning, rainfall, vertical hydrometeor profiles, latent heating, wind variability and aerosol optical thickness are analyzed. The characteristics of lightning and precipitation over four oceanic zones adjacent to Mexican coastlines are contrasted against those over the continent. In addition, we compare two smaller regions over the Tropical Pacific Ocean: one located within the Inter-Tropical Converge Zone and characterized by high rainfall and weak lightning activity and the other influenced by a continental jet and presenting high rainfall and strong lightning activity over the Gulf of Tehuantepec. Maritime precipitating clouds that develop within the region influenced by offshore winds exhibit similar properties to continental clouds: large content of precipitation ice and an increased height range of coexistence of precipitation ice and cloud water. During the rainy season, monthly distribution of lightning within the region influenced by the continental jet is contrary to that of rainfall. Moreover, the monthly variability of lightning is very similar to the variability of the meridional wind component and it is also related to the variability of aerosol optical depth. The analysis strongly suggests that the high lightning activity observed over the Gulf of Tehuantepec is caused by continental cloud condensation nuclei advected over the ocean.

  13. Identifying High School Physical Education Physical Activity Patterns after High School

    Science.gov (United States)

    Barney, David; Pleban, Francis T.; Wilkinson, Carol; Prusak, Keven A.

    2015-01-01

    National standards for physical education (PE) encompass five principles for the purpose of defining what high school students should recognize and be able to perform as a result of a quality PE program. The expectation is that youth will develop an active, healthy lifestyle into adulthood from activities and skills taught in PE. Researchers from…

  14. Physical Activity in High School during "Free-Time" Periods

    Science.gov (United States)

    Silva, Pedro; Sousa, Michael; Sá, Carla; Ribeiro, José; Mota, Jorge

    2015-01-01

    The purpose of this study was to examine youth physical activity (PA) in free-time periods during high school days and their contribution to total PA. Differences in terms of sex, age, body mass index and school level were assessed in a sample of Portuguese adolescents. Participants totalled 213 (135 girls), aged 14.6 ± 1.7, from two different…

  15. High Frequency State-Variable Biquadratic Active Filters

    Directory of Open Access Journals (Sweden)

    T. Dostal

    1998-04-01

    Full Text Available The state-variable (KHN active RC biquadratic filters with good performance in high frequency range , flexibility of outputs (LP, HP, BP, low sensitivities in novel current and hybrid modes, using current conveyors, transimpedance, trans-admittance and current operational amplifiers, are given in this paper.

  16. High hydrostatic pressure treatment of porcine oocytes induces parthenogenetic activation

    DEFF Research Database (Denmark)

    Lin, Lin; Pribenszky, Csaba; Molnár, Miklós

    2010-01-01

    An innovative technique called high hydrostatic pressure (HHP) treatment has recently been reported to improve the cryosurvival of gametes and embryos in certain mammalian species, including the mouse, pig, and cattle. In the present study the parthenogenetic activation (PA) of pig oocytes caused...

  17. Reduced autonomic activity during stepwise exposure to high altitude

    NARCIS (Netherlands)

    Sevre, K; Bendz, B; Hanko, E; Nakstad, AR; Hauge, A; Kasin, JI; Lefrandt, JD; Smit, AJ; Eide, [No Value; Rostrup, M

    2001-01-01

    Several studies have shown increased sympathetic activity during acute exposure to hypobaric hypoxia. In a recent field study we found reduced plasma catecholamines during the first days after a stepwise ascent to high altitude. In the present study 14 subjects were exposed to a simulated ascent in

  18. Development activities of the high heat flux scraper element

    Energy Technology Data Exchange (ETDEWEB)

    Boscary, J., E-mail: jean.boscary@ipp.mpg.de [Max Planck Institute for Plasma Physics, Garching (Germany); Lore, J.; Lumsdaine, A. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Maier, M. [Max Planck Institute for Plasma Physics, Garching (Germany); McGinnis, D. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Peacock, A.; Tretter, J. [Max Planck Institute for Plasma Physics, Garching (Germany)

    2015-10-15

    The function of the high heat flux scraper element is to reduce the heat loads on the element ends of the actively cooled divertor of Wendelstein 7-X. The scraper element is actively water cooled to remove up to 550 kW steady state power load, with localized heat fluxes as high as 20 MW/m{sup 2}. Its surface area, 0.17 m{sup 2}, is contoured to optimally intercept both upstream and downstream particle fluxes. The plasma facing surface is made of 24 individual scraper fingers based on the monoblock technology. Each scraper finger is 247 mm long and 28 mm wide and has 13 monoblocks made of CFC NB31 bonded by hot isostatic pressing onto a CuCrZr cooling tube equipped with a copper twisted tape. Development activities, described here, include the design and fabrication of prototypes to validate the different technologies selected for the scraper element design to prepare a possible production.

  19. Review of actuators for high speed active flow control

    Institute of Scientific and Technical Information of China (English)

    WANG Lin; LUO ZhenBing; XIA ZhiXun; LIU Bing; DENG Xiong

    2012-01-01

    Actuators are one of the key points for the development of active flow control technology.Efficient methods of high speed flow control can provide enhanced propulsive efficiency and at the same time enable safe and maneuverable high speed flight.The development of high speed flight technology promotes the emergence of novel and robust actuators.This review introduces the state of the art in the development of actuators that can be used in high speed active flow control.The classification and different operation criteria of the actuators are discussed.The specifications,mechanisms and applications of various popular actuator types including fluidic,mechanical,and plasma actuators are described.Based on the realistic need of high speed flow control and the existing results of actuators,a new actuator design method is proposed.At last,the merits and drawbacks of the actuators are summarized and some suggestions on the development of active flow control technology are put forward.

  20. High efficiency cell-specific targeting of cytokine activity

    Science.gov (United States)

    Garcin, Geneviève; Paul, Franciane; Staufenbiel, Markus; Bordat, Yann; van der Heyden, José; Wilmes, Stephan; Cartron, Guillaume; Apparailly, Florence; de Koker, Stefaan; Piehler, Jacob; Tavernier, Jan; Uzé, Gilles

    2014-01-01

    Systemic toxicity currently prevents exploiting the huge potential of many cytokines for medical applications. Here we present a novel strategy to engineer immunocytokines with very high targeting efficacies. The method lies in the use of mutants of toxic cytokines that markedly reduce their receptor-binding affinities, and that are thus rendered essentially inactive. Upon fusion to nanobodies specifically binding to marker proteins, activity of these cytokines is selectively restored for cell populations expressing this marker. This ‘activity-by-targeting’ concept was validated for type I interferons and leptin. In the case of interferon, activity can be directed to target cells in vitro and to selected cell populations in mice, with up to 1,000-fold increased specific activity. This targeting strategy holds promise to revitalize the clinical potential of many cytokines.

  1. Business cycle and innovation activity in medium-high and high technology industry in Poland

    Directory of Open Access Journals (Sweden)

    Dzikowski Piotr

    2015-12-01

    Full Text Available This article examines differences in an impact of business cycle phases on innovation activity in medium-high and high technology industry in Poland. It is assumed that each business cycle phase influences innovation activity in the same fashion, but its impact varies and it depends on the firm’s innovation activity. The higher innovation activity the less impact of business cycle. The scope of the survey relates to innovation in MHT and HT industry in Poland. The data concerns the innovation at the firm level and the diffusion “new for the company”. Innovation activity is defined by the following activities: (1 expenditure on research and development and investments in fixed assets not used so far such as: abuildings, premises and land; b machinery and equipment, c computer software; (2 implementation of new products and technological processes and (3 innovation cooperation. The methodological part of the analysis includes a logit modeling. The survey includes 1355 companies. Business cycle has a great influence on innovation activity in MTH and HT industry in Poland. The influence of recovery phase is positive whereas both stagnation and recession phases decrease the probability of innovation activity. The character of influence depends on the propensity to take innovation activity. The higher level of innovation activity the enterprises present the less influence of business cycle they get.

  2. Physical properties of highly active liquor containing molybdate solids

    Energy Technology Data Exchange (ETDEWEB)

    Dunnett, B.; Ward, T.; Roberts, R. [National Nuclear Laboratory, Sellafield, Seascale, Cumbria, CA20 1PG (United Kingdom); Cheeseright, J. [Sellafield Ltd, Sellafield, Seascale, Cumbria, CA20 1PG (United Kingdom)

    2016-07-01

    The reprocessing of irradiated nuclear fuel at Sellafield produces a nitric acid based Highly Active Liquor (HAL) waste. The liquor, containing fission products and process additives, is concentrated in an evaporator in order to reduce the volume and is then stored in Highly Active Storage Tanks (HASTs) prior to vitrification. Caesium phosphomolybdate (CPM) is precipitated during the evaporation process and can convert to zirconium molybdate (ZM) during storage. During Post Operational Clean Out (POCO) of the HASTs, it is expected that their highly active content will be reduced by repeated cycles of washing using nitric acid and other reagents. Initial washings are likely to have a chemical composition comparable to concentrated HAL, becoming more dilute during the wash-out process. It is expected that the wash-out process will also recover significant quantities of molybdate solids (ZM, CPM or a mixture) from the HASTs. In order to determine the processing challenges from such washings during POCO, the physical properties of varying concentrations of non-active HAL simulants containing molybdate solids have recently been measured by the UK's National Nuclear Laboratory. The following measurements are presented and discussed: Particle size distribution; Density; Settling behaviour of solids; Voidage of settled sediment beds; Viscosity; Yield stress; And influence of ZM morphology on physical properties. (authors)

  3. Highly porous activated carbons prepared from carbon rich Mongolian anthracite by direct NaOH activation

    Energy Technology Data Exchange (ETDEWEB)

    Byamba-Ochir, Narandalai [School of Chemical Engineering, Chonnam National University, 77 Yongbong-Ro, Gwangju 61186 (Korea, Republic of); Shim, Wang Geun [Department of Polymer Science and Engineering, Sunchon National University, 255 Jungang-Ro, Suncheon, Jeollanam-Do 57922 (Korea, Republic of); Balathanigaimani, M.S., E-mail: msbala@rgipt.ac.in [Department of Chemical Engineering, Rajiv Gandhi Institute of Petroleum Technology, Ratapur Chowk, Rae Bareli, 229316 Uttar Pradesh (India); Moon, Hee, E-mail: hmoon@jnu.ac.kr [School of Chemical Engineering, Chonnam National University, 77 Yongbong-Ro, Gwangju 61186 (Korea, Republic of)

    2016-08-30

    Highlights: • Highly porous carbon materials from Mongolian anthracite by chemical activation. • Cheaper and eco-friendly activation process has been employed. • Activated carbons with graphitic structure and energetically heterogeneous surface. • Surface hydrophobicity and porosity of the activated carbons can be controlled. - Abstract: Highly porous activated carbons (ACs) were prepared from Mongolian raw anthracite (MRA) using sodium hydroxide as an activation agent by varying the mass ratio (powdered MRA/NaOH) as well as the mixing method of chemical agent and powdered MRA. The specific BET surface area and total pore volume of the prepared MRA-based activated carbons (MACs) are in the range of 816–2063 m{sup 2}/g and of 0.55–1.61 cm{sup 3}/g, respectively. The pore size distribution of MACs show that most of the pores are in the range from large micropores to small mesopores and their distribution can be controlled by the mass ratio and mixing method of the activating agent. As expected from the intrinsic property of the MRA, the highly graphitic surface morphology of prepared carbons was confirmed from Raman spectra and transmission electron microscopy (TEM) studies. Furthermore the FTIR and XPS results reveal that the preparation of MACs with hydrophobic in nature is highly possible by controlling the mixing conditions of activating agent and powdered MRA. Based on all the results, it is suggested that the prepared MACs could be used for many specific applications, requiring high surface area, optimal pore size distribution, proper surface hydrophobicity as well as strong physical strength.

  4. High lightning activity in maritime clouds near Mexico

    Science.gov (United States)

    Kucienska, B.; Raga, G. B.; Romero-Centeno, R.

    2012-09-01

    Lightning activity detected by the World Wide Lightning Location Network (WWLLN) over oceanic regions adjacent to Mexico is often as high as that observed over the continent. In order to explore the possible causes of the observed high flash density over those regions, the relationships between lightning, rainfall, vertical hydrometeor profiles, latent heating, wind variability and aerosol optical depth are analyzed. The characteristics of lightning and precipitation over four oceanic zones adjacent to Mexican coastlines are contrasted against those over the continent. The number of flashes per rainfall over some coastal maritime regions is found to be higher than over the continent. The largest number of flashes per rainfall is observed during the biomass burning season. In addition, we compare two smaller areas of the Tropical Pacific Ocean: one located within the Inter-Tropical Convergence Zone and characterized by high rainfall and weak lightning activity and the other one influenced by a continental wind jet and characterized by high rainfall and strong lightning activity. During the rainy season, the monthly distribution of lightning within the region influenced by the continental wind jet is contrary to that of rainfall. Moreover, the monthly variability of lightning is very similar to the variability of the meridional wind component and it is also related to the variability of aerosol optical depth. The analysis suggests that the high lightning activity observed over coastal Pacific region is linked to the continental cloud condensation nuclei advected over the ocean. Analysis of daily observations indicates that the greatest lightning density is observed for moderate values of the aerosol optical depth, between 0.2 and 0.35.

  5. A simple and highly effective process for the preparation of activated carbons with high surface area

    Energy Technology Data Exchange (ETDEWEB)

    Li Ying, E-mail: liyingjlu@163.com [College of Chemistry, Jilin University, Changchun 130012 (China); Ding Xuefeng; Guo Yupeng; Wang Lili; Rong Chunguang; Qu Yuning; Ma Xiaoyu [College of Chemistry, Jilin University, Changchun 130012 (China); Wang Zichen, E-mail: wangzc@jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130012 (China)

    2011-06-15

    Highlights: {yields} High surface area activated carbon can be prepared by rice husk H{sub 3}PO{sub 4} without pretreatment. {yields} The characteristics of the activated carbon were greatly influenced by post-processing method. {yields} The lower SiO{sub 2} content of the activated carbons, the higher pore volume the carbons had. {yields} Some silica in rice husk reacted with H{sub 3}PO{sub 4} to form SiP{sub 2}O{sub 7} which could be removed by post-process. - Abstract: Activated carbons with high surface area were prepared by phosphoric acid as activation agent and rice husks as precursors. It was found that the characteristics of the activated carbons were influenced not only by the preparation but also by the post-processing method. The high surface area of the activated carbons was prepared under the optimum condition (50% H{sub 3}PO{sub 4} with impregnation ratio of 5:1, activation temperature of 500 deg. C, activation time of 0.5 h, wash water temperature of 100 deg. C). SiO{sub 2} content could affect the surface area of activated carbons, either. The lower SiO{sub 2} content of the activated carbons, the higher pore volume the carbons had. The SiO{sub 2} content was 11.2% when used the optimum condition. The explanation was that silicon element in rice husks reacted with H{sub 3}PO{sub 4} to form silicon phosphate (SiP{sub 2}O{sub 7}), and it could be proved further by X-ray diffraction analysis, SiP{sub 2}O{sub 7} could be removed by post-process.

  6. Active Photonic crystal fibers for high power applications

    DEFF Research Database (Denmark)

    Olausson, Christina Bjarnal Thulin

    . This plays an important role in high power lasers and ampliers with respect to efficiency, packaging, and thermal handling. The third part of the work has involved developing tools for characterizing the mode quality and stability of large core bers. Stable, single-mode bers with larger cores are essential......The photonic crystal ber technology provides means to realize bers optimized for high power operation, due to the large single-mode cores and the unique design exibility of the microstructure. The work presented in this thesis focuses on improving the properties of active photonic crystal bers...... for high power ber lasers and ampliers, and on adding new functionality to the fibers - all with the purpose of pushing the technology towards high powers. The first part of the work has been to investigate photo darkening, the mitigation of which is crucial in the quest for higher powers. The work has...

  7. Preclinical Study for Application of Fabricated High Activity Ir-192

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Mi Son; Kang, Seung Hee; Oh, Young Taek; Jeong, Chul; Kim, Mi Hwa; Hwang, Jeong Hye; Kim, Hee Seong; Im, Eun Jeong [Ajou University, Suwon (Korea, Republic of)

    2005-10-15

    This study was performed to evaluate the feasibility and safety of high activity Ir-192 sources manufactured by KAERI(Korea Atomic Energy Research Institute) for application to present equipment such as various applicators inserted to patients and PLATO(Nucletron, Netherland) of treatment planning system and to evaluate safety and accuracy of Ir-192 as practical clinic use through in vitro dosimetry of Ir-192. We confirmed the physical and radiobiological safety of KAERI sources to use practical. KAERI sources are applicable to commercial high dose rate brachytherapy machine safely. Then those can be substituted for the imported sources such as sources made by Nucletron, Gammamed and exported to the foreign country

  8. Activated blended cement containing high volume coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Shi, C.J.; Qian, J.S. [CJS Technology Inc., Burlington, ON (Canada)

    2001-10-01

    This study investigated the strength and equilibrium water extraction of blended cement containing high volume coal fly ash and activator CaCl{sub 2}. The addition of CaCl{sub 2} increased the strength of cement very significantly. Equilibrium water extraction indicated that the addition of CaCl{sub 2} decreased the pH of the pore solution, but accelerated the pozzolanic reactions between coal fly ash and lime, which became more obvious when the volume of fly ash in the cement was increased from 50-70%. Results from both strength and water extraction testing could conclude that CaCl{sub 2} is a good activator for the activation of pozzolanic reactivity of fly ash and for the improvement of early properties of fly ash cement and concrete.

  9. Accelerator Production and Separations for High Specific Activity Rhenium-186

    Energy Technology Data Exchange (ETDEWEB)

    Jurisson, Silvia S. [Univ. of Missouri, Columbia, MO (United States); Wilbur, D. Scott [Univ. of Washington, Seattle, WA (United States)

    2016-04-01

    Tungsten and osmium targets were evaluated for the production of high specific activity rhenium-186. Rhenium-186 has potential applications in radiotherapy for the treatment of a variety of diseases, including targeting with monoclonal antibodies and peptides. Methods were evaluated using tungsten metal, tungsten dioxide, tungsten disulfide and osmium disulfide. Separation of the rhenium-186 produced and recycling of the enriched tungsten-186 and osmium-189 enriched targets were developed.

  10. Mining Chemical Activity Status from High-Throughput Screening Assays

    KAUST Repository

    Soufan, Othman

    2015-12-14

    High-throughput screening (HTS) experiments provide a valuable resource that reports biological activity of numerous chemical compounds relative to their molecular targets. Building computational models that accurately predict such activity status (active vs. inactive) in specific assays is a challenging task given the large volume of data and frequently small proportion of active compounds relative to the inactive ones. We developed a method, DRAMOTE, to predict activity status of chemical compounds in HTP activity assays. For a class of HTP assays, our method achieves considerably better results than the current state-of-the-art-solutions. We achieved this by modification of a minority oversampling technique. To demonstrate that DRAMOTE is performing better than the other methods, we performed a comprehensive comparison analysis with several other methods and evaluated them on data from 11 PubChem assays through 1,350 experiments that involved approximately 500,000 interactions between chemicals and their target proteins. As an example of potential use, we applied DRAMOTE to develop robust models for predicting FDA approved drugs that have high probability to interact with the thyroid stimulating hormone receptor (TSHR) in humans. Our findings are further partially and indirectly supported by 3D docking results and literature information. The results based on approximately 500,000 interactions suggest that DRAMOTE has performed the best and that it can be used for developing robust virtual screening models. The datasets and implementation of all solutions are available as a MATLAB toolbox online at www.cbrc.kaust.edu.sa/dramote and can be found on Figshare.

  11. Mining Chemical Activity Status from High-Throughput Screening Assays.

    Directory of Open Access Journals (Sweden)

    Othman Soufan

    Full Text Available High-throughput screening (HTS experiments provide a valuable resource that reports biological activity of numerous chemical compounds relative to their molecular targets. Building computational models that accurately predict such activity status (active vs. inactive in specific assays is a challenging task given the large volume of data and frequently small proportion of active compounds relative to the inactive ones. We developed a method, DRAMOTE, to predict activity status of chemical compounds in HTP activity assays. For a class of HTP assays, our method achieves considerably better results than the current state-of-the-art-solutions. We achieved this by modification of a minority oversampling technique. To demonstrate that DRAMOTE is performing better than the other methods, we performed a comprehensive comparison analysis with several other methods and evaluated them on data from 11 PubChem assays through 1,350 experiments that involved approximately 500,000 interactions between chemicals and their target proteins. As an example of potential use, we applied DRAMOTE to develop robust models for predicting FDA approved drugs that have high probability to interact with the thyroid stimulating hormone receptor (TSHR in humans. Our findings are further partially and indirectly supported by 3D docking results and literature information. The results based on approximately 500,000 interactions suggest that DRAMOTE has performed the best and that it can be used for developing robust virtual screening models. The datasets and implementation of all solutions are available as a MATLAB toolbox online at www.cbrc.kaust.edu.sa/dramote and can be found on Figshare.

  12. Mining Chemical Activity Status from High-Throughput Screening Assays.

    Science.gov (United States)

    Soufan, Othman; Ba-alawi, Wail; Afeef, Moataz; Essack, Magbubah; Rodionov, Valentin; Kalnis, Panos; Bajic, Vladimir B

    2015-01-01

    High-throughput screening (HTS) experiments provide a valuable resource that reports biological activity of numerous chemical compounds relative to their molecular targets. Building computational models that accurately predict such activity status (active vs. inactive) in specific assays is a challenging task given the large volume of data and frequently small proportion of active compounds relative to the inactive ones. We developed a method, DRAMOTE, to predict activity status of chemical compounds in HTP activity assays. For a class of HTP assays, our method achieves considerably better results than the current state-of-the-art-solutions. We achieved this by modification of a minority oversampling technique. To demonstrate that DRAMOTE is performing better than the other methods, we performed a comprehensive comparison analysis with several other methods and evaluated them on data from 11 PubChem assays through 1,350 experiments that involved approximately 500,000 interactions between chemicals and their target proteins. As an example of potential use, we applied DRAMOTE to develop robust models for predicting FDA approved drugs that have high probability to interact with the thyroid stimulating hormone receptor (TSHR) in humans. Our findings are further partially and indirectly supported by 3D docking results and literature information. The results based on approximately 500,000 interactions suggest that DRAMOTE has performed the best and that it can be used for developing robust virtual screening models. The datasets and implementation of all solutions are available as a MATLAB toolbox online at www.cbrc.kaust.edu.sa/dramote and can be found on Figshare.

  13. Fibrinolytic changes in pregnant women on highly active antiretroviral therapy.

    Science.gov (United States)

    Osime, Odaburhine E; Ese-Onakewhor, Joseph U; Kolade, Samson O

    2015-02-01

    To report on the changes in fibrinolytic activity in human immunodeficiency virus (HIV) infected pregnant women who are undergoing highly active antiretroviral therapy (HAART). Blood was collected from 50 HIV positive women on HAART (test subjects), and 50 HIV positive women not on HAART (controls). These women were attending the prevention of mother to child clinic (PMTCT) of the University of Benin Teaching Hospital, Benin City, Nigeria from January to June 2014. Standard manual techniques were used to estimate plasma fibrinogen concentration (PFC), euglobulin lysis time (ELT), packed cell volume (PCV), and plasma viscosity (PV). The mean ± standard error of mean (SEM) of PFC was 4.02±0.13 g/l and ELT from the test subjects was 378±15 mins was significantly higher (p0.05). There were differences in the various parameters investigated when the various trimesters were compared. These differences did not, however, follow a particular pattern. Highly active antiretroviral therapy can cause changes in fibrinolytic activity that may predispose pregnant women to hyperfibrinogenemia and anemia.

  14. High Electrocatalytic Hydrogen Evolution Activity of an Anomalous Ruthenium Catalyst

    KAUST Repository

    Zheng, Yao

    2016-11-28

    Hydrogen evolution reaction (HER) is a critical process due to its fundamental role in electrocatalysis. Practically, the development of high-performance electrocatalysts for HER in alkaline media is of great importance for the conversion of renewable energy to hydrogen fuel via photoelectrochemical water splitting. However, both mechanistic exploration and materials development for HER under alkaline conditions are very limited. Precious Pt metal, which still serves as the state-of-the-art catalyst for HER, is unable to guarantee a sustainable hydrogen supply. Here we report an anomalously structured Ru catalyst that shows 2.5 times higher hydrogen generation rate than Pt and is among the most active HER electrocatalysts yet reported in alkaline solutions. The identification of new face-centered cubic crystallographic structure of Ru nanoparticles was investigated by high-resolution transmission electron microscopy imaging, and its formation mechanism was revealed by spectroscopic characterization and theoretical analysis. For the first time, it is found that the Ru nanocatalyst showed a pronounced effect of the crystal structure on the electrocatalytic activity tested under different conditions. The combination of electrochemical reaction rate measurements and density functional theory computation shows that the high activity of anomalous Ru catalyst in alkaline solution originates from its suitable adsorption energies to some key reaction intermediates and reaction kinetics in the HER process.

  15. AHEAD: Integrated Activities in the High Energy Astrophysics Domain

    Science.gov (United States)

    Piro, Luigi; Natalucci, Lorenzo; Ahead Consortium

    2015-09-01

    AHEAD (Integrated Activities in the High Energy Astrophysics Domain) is a forthcoming project approved in the framework of the European Horizon 2020 program (Research Infrastructures for High Energy Astrophysics). The overall objective of AHEAD is to integrate national efforts in high-energy Astrophysics and to promote the domain at the European level, to keep its community at the cutting edge of science and technology and ensure that space observatories for high-energy astrophysics, with particular regard to Athena, are at the state of the art. AHEAD will integrate key research infrastructures for on-ground test and calibration of space-based sensors and electronics and promote their coordinated use. In parallel, the best facilities for data analysis of high-energy astrophysical observatories will be made available to the European community. The technological development will focus on the improvement of selected critical technologies, background modeling, cross calibration, and feasibility studies of space-based instrumentation for the benefit of future high energy missions like Athena, and the best exploitation of existing observatories. AHEAD will support the community via grants for collaborative studies, dissemination of results, and promotion of workshops. A strong public outreach package will ensure that the domain is well publicized at national, European and International level. Networking, joint research activities and access to infrastructures as devised in AHEAD, will serve to establish strong connections between institutes and industry to create the basis for a more rapid advancement of high-energy astrophysical science, space oriented instrumentation and cutting-edge sensor technology in Europe. This enables the development of new technologies and the associated growth of the European technology market with a dedicated technology innovation package, as well as the creation of a new generation of researchers.

  16. High Sulfation and a High Molecular Weight Are Important for Anti-hepcidin Activity of Heparin

    Science.gov (United States)

    Asperti, Michela; Naggi, Annamaria; Esposito, Emiliano; Ruzzenenti, Paola; Di Somma, Margherita; Gryzik, Magdalena; Arosio, Paolo; Poli, Maura

    2016-01-01

    Heparins are efficient inhibitors of hepcidin expression even in vivo, where they induce an increase of systemic iron availability. Heparins seem to act by interfering with BMP6 signaling pathways that control the expression of liver hepcidin, causing the suppression of SMAD1/5/8 phosphorylation. The anti-hepcidin activity persists also when the heparin anticoagulant property is abolished or reduced by chemical reactions of oxidation/reduction (glycol-split, Gs-Heparins) or by high sulfation (SS-Heparins), but the structural characteristics needed to optimize this inhibitory activity have not been studied in detail. To this aim we analyzed three different heparins (Mucosal Heparin, the Glycol split RO-82, the partially desulfated glycol-split RO-68 and the oversulfated SSLMWH) and separated them in fractions of molecular weight in the range 4–16 kD. Since the distribution of the negative charges in heparins contributes to the activity, we produced 2-O- and 6-O-desulfated heparins. These derivatives were analyzed for the capacity to inhibit hepcidin expression in hepatic HepG2 cells and in mice. The two approaches produced consistent results and showed that the anti-hepcidin activity strongly decreases with molecular weight below 7 kD, with high N-acetylation and after 2-O and 6-O desulfation. The high sulfation and high molecular weight properties for efficient anti-hepcidin activity suggest that heparin is involved in multiple binding sites. PMID:26955355

  17. Active beam integrator for high power coherent lasers

    Energy Technology Data Exchange (ETDEWEB)

    Laguarta, F.; Armengol, J.; Vega, F.; Lupon, N. [Univ. Politecnica de Catalunya, Terrassa (Spain). Dept. d`Optica i Optometria

    1996-12-31

    In laser materials processing applications it is often necessary to work with uniform intensity distributions. This goal is quite difficult to achieve when dealing with high power laser beams, and becomes critical for a successful application involving surface heat treatment of non-metallic materials. The authors have designed and tested a very simple beam shaper for transforming the initial intensity distribution of a CO{sub 2} laser beam mode into a more uniform intensity profile. The beam shaper is a two-faceted mirror for active integration of high power coherent laser beams. After reflection in the faceted mirror, a TEM00 or TEM01 CO{sub 2} laser beam is divided into two beamlets that overlap to give a more uniform intensity distribution. A sharp interference pattern due to the high spatial coherence of the incident beam appears. This interference pattern is actively integrated by a high-frequency longitudinal displacement of one of the facets. This provides a change in the relative phase of the two beamlets, and consequently the interference pattern vibrates and its contribution to the intensity distribution averages out. When sweeping this distribution over a sample, a uniform amount of energy is deposited at every point of its surface. It must be emphasized that unlike multifaceted mirrors, the two-facet integrator may provide uniform intensity profiles over any working distance. Finally, as in other integration devices an imaging system may be used to obtain a spot of the shape and the size desired for a particular application.

  18. Microbial fuel cells with highly active aerobic biocathodes

    Science.gov (United States)

    Milner, Edward M.; Popescu, Dorin; Curtis, Tom; Head, Ian M.; Scott, Keith; Yu, Eileen H.

    2016-08-01

    Microbial fuel cells (MFCs), which convert organic waste to electricity, could be used to make the wastewater infrastructure more energy efficient and sustainable. However, platinum and other non-platinum chemical catalysts used for the oxygen reduction reaction (ORR) at the cathode of MFCs are unsustainable due to their high cost and long-term degradation. Aerobic biocathodes, which use microorganisms as the biocatalysts for cathode ORR, are a good alternative to chemical catalysts. In the current work, high-performing aerobic biocathodes with an onset potential for the ORR of +0.4 V vs. Ag/AgCl were enriched from activated sludge in electrochemical half-cells poised at -0.1 and + 0.2 V vs. Ag/AgCl. Gammaproteobacteria, distantly related to any known cultivated gammaproteobacterial lineage, were identified as dominant in these working electrode biofilms (23.3-44.3% of reads in 16S rRNA gene Ion Torrent libraries), and were in very low abundance in non-polarised control working electrode biofilms (0.5-0.7%). These Gammaproteobacteria were therefore most likely responsible for the high activity of biologically catalysed ORR. In MFC tests, a high-performing aerobic biocathode increased peak power 9-fold from 7 to 62 μW cm-2 in comparison to an unmodified carbon cathode, which was similar to peak power with a platinum-doped cathode at 70 μW cm-2.

  19. Highly porous activated carbons prepared from carbon rich Mongolian anthracite by direct NaOH activation

    Science.gov (United States)

    Byamba-Ochir, Narandalai; Shim, Wang Geun; Balathanigaimani, M. S.; Moon, Hee

    2016-08-01

    Highly porous activated carbons (ACs) were prepared from Mongolian raw anthracite (MRA) using sodium hydroxide as an activation agent by varying the mass ratio (powdered MRA/NaOH) as well as the mixing method of chemical agent and powdered MRA. The specific BET surface area and total pore volume of the prepared MRA-based activated carbons (MACs) are in the range of 816-2063 m2/g and of 0.55-1.61 cm3/g, respectively. The pore size distribution of MACs show that most of the pores are in the range from large micropores to small mesopores and their distribution can be controlled by the mass ratio and mixing method of the activating agent. As expected from the intrinsic property of the MRA, the highly graphitic surface morphology of prepared carbons was confirmed from Raman spectra and transmission electron microscopy (TEM) studies. Furthermore the FTIR and XPS results reveal that the preparation of MACs with hydrophobic in nature is highly possible by controlling the mixing conditions of activating agent and powdered MRA. Based on all the results, it is suggested that the prepared MACs could be used for many specific applications, requiring high surface area, optimal pore size distribution, proper surface hydrophobicity as well as strong physical strength.

  20. Active Change in Psychodynamic Therapy: Moments of High Receptiveness.

    Science.gov (United States)

    De Gauna, Mariano De Iceta Ibáñez; Roibal, M Angela Soler; Ruiz, José Antonio Méndez; Fernández, Joaquin Ingelmo; Bleichmar, Hugo B

    2015-01-01

    This article presents the concept of "moments of high receptiveness" (MoHR or "Momentos de Alta Receptividad"), which is derived from the concept of "experiential coupling" ("Acoplamiento de Experiencias") proposed by Bleichmar (2001). Experiential coupling recently received empirical support by the work of Schiller and colleagues (2010). We will also show the conceptual placing of moments of high receptiveness with respect to the developments of Stern and colleagues (Stern and et al., 1998; Stern, 2004). In order to achieve both objectives, we focus on various clinical vignettes stressing the differences in repercussions of the technique. We describe use of stimuli for active evocation, explain how to identify moments of high receptiveness, and review ways to take advantage of these moments. Lastly, to minimize the risk of iatrogenic symptoms, we examine the role of therapists and some features of the therapeutic process when using this technique.

  1. Telomerase activation by genomic rearrangements in high-risk neuroblastoma.

    Science.gov (United States)

    Peifer, Martin; Hertwig, Falk; Roels, Frederik; Dreidax, Daniel; Gartlgruber, Moritz; Menon, Roopika; Krämer, Andrea; Roncaioli, Justin L; Sand, Frederik; Heuckmann, Johannes M; Ikram, Fakhera; Schmidt, Rene; Ackermann, Sandra; Engesser, Anne; Kahlert, Yvonne; Vogel, Wenzel; Altmüller, Janine; Nürnberg, Peter; Thierry-Mieg, Jean; Thierry-Mieg, Danielle; Mariappan, Aruljothi; Heynck, Stefanie; Mariotti, Erika; Henrich, Kai-Oliver; Gloeckner, Christian; Bosco, Graziella; Leuschner, Ivo; Schweiger, Michal R; Savelyeva, Larissa; Watkins, Simon C; Shao, Chunxuan; Bell, Emma; Höfer, Thomas; Achter, Viktor; Lang, Ulrich; Theissen, Jessica; Volland, Ruth; Saadati, Maral; Eggert, Angelika; de Wilde, Bram; Berthold, Frank; Peng, Zhiyu; Zhao, Chen; Shi, Leming; Ortmann, Monika; Büttner, Reinhard; Perner, Sven; Hero, Barbara; Schramm, Alexander; Schulte, Johannes H; Herrmann, Carl; O'Sullivan, Roderick J; Westermann, Frank; Thomas, Roman K; Fischer, Matthias

    2015-10-29

    Neuroblastoma is a malignant paediatric tumour of the sympathetic nervous system. Roughly half of these tumours regress spontaneously or are cured by limited therapy. By contrast, high-risk neuroblastomas have an unfavourable clinical course despite intensive multimodal treatment, and their molecular basis has remained largely elusive. Here we have performed whole-genome sequencing of 56 neuroblastomas (high-risk, n = 39; low-risk, n = 17) and discovered recurrent genomic rearrangements affecting a chromosomal region at 5p15.33 proximal of the telomerase reverse transcriptase gene (TERT). These rearrangements occurred only in high-risk neuroblastomas (12/39, 31%) in a mutually exclusive fashion with MYCN amplifications and ATRX mutations, which are known genetic events in this tumour type. In an extended case series (n = 217), TERT rearrangements defined a subgroup of high-risk tumours with particularly poor outcome. Despite a large structural diversity of these rearrangements, they all induced massive transcriptional upregulation of TERT. In the remaining high-risk tumours, TERT expression was also elevated in MYCN-amplified tumours, whereas alternative lengthening of telomeres was present in neuroblastomas without TERT or MYCN alterations, suggesting that telomere lengthening represents a central mechanism defining this subtype. The 5p15.33 rearrangements juxtapose the TERT coding sequence to strong enhancer elements, resulting in massive chromatin remodelling and DNA methylation of the affected region. Supporting a functional role of TERT, neuroblastoma cell lines bearing rearrangements or amplified MYCN exhibited both upregulated TERT expression and enzymatic telomerase activity. In summary, our findings show that remodelling of the genomic context abrogates transcriptional silencing of TERT in high-risk neuroblastoma and places telomerase activation in the centre of transformation in a large fraction of these tumours.

  2. Passive and Active Monitoring on a High Performance Research Network.

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Warren

    2001-05-01

    The bold network challenges described in ''Internet End-to-end Performance Monitoring for the High Energy and Nuclear Physics Community'' presented at PAM 2000 have been tackled by the intrepid administrators and engineers providing the network services. After less than a year, the BaBar collaboration has collected almost 100 million particle collision events in a database approaching 165TB (Tera=10{sup 12}). Around 20TB has been exported via the Internet to the BaBar regional center at IN2P3 in Lyon, France, for processing and around 40 TB of simulated events have been imported to SLAC from Lawrence Livermore National Laboratory (LLNL). An unforseen challenge has arisen due to recent events and highlighted security concerns at DoE funded labs. New rules and regulations suggest it is only a matter of time before many active performance measurements may not be possible between many sites. Yet, at the same time, the importance of understanding every aspect of the network and eradicating packet loss for high throughput data transfers has become apparent. Work at SLAC to employ passive monitoring using netflow and OC3MON is underway and techniques to supplement and possibly replace the active measurements are being considered. This paper will detail the special needs and traffic characterization of a remarkable research project, and how the networking hurdles have been resolved (or not!) to achieve the required high data throughput. Results from active and passive measurements will be compared, and methods for achieving high throughput and the effect on the network will be assessed along with tools that directly measure throughput and applications used to actually transfer data.

  3. High Performance Activity Practices in Small Firms in Romania

    Directory of Open Access Journals (Sweden)

    Gabriela ŢUŢUEANU

    2014-12-01

    Full Text Available High Performance Activity Practices in Small Firms in Romania Abstract: High performance activity practices (HPAPs are human resource management activities aimed at stimulating employee and organisational performance. The application of HPAPs is not widespread in small organisations. We examine whether the implementation of coherent bundles of HPAPs (aimed at employee ability, employee motivation or at the opportunity to perform depends on the scarcity of resources, as reflected in the size of the company, and on strategic decision-making in small firms related to the owner’s expertise and attitudes. In our research, a total of 224 employees from 50 small organisations were asked to rate the presence of HPAPs in their organisation. These averaged perceptions were linked to information provided by the owner–managers on the size of their firm and their own expertise and attitudes. The findings support that smaller but coherent bundles of HPAPs can be found in small organisations and that the implementation of these bundles depends on available resources, strategic decision-making and the combination of the two. These findings highlight the need to integrate the notions of resource poverty and strategic decision-making to understand the uptake of bundles of HPAPs within small firms.

  4. Use of dominant harmonic active filters in high power applications

    Science.gov (United States)

    Cheng, Po-Tai

    The application of power electronics equipment is increasing rapidly. It is estimated that 60% of electrical power will be processed by power electronics equipment by year 2000. These equipments typically require rectifiers for AC-DC power conversion. Due to their nonlinear nature, most rectifiers draw harmonic current from the utility grid. The harmonic current causes higher energy losses, and may excite resonance conditions in the utility grid. Harmonic standards such as IEEE 519 and IEC 1000-3-2 have been proposed to regulate the harmonic current and voltage levels. This work is to develop a dominant harmonic active filter (DHAF) to realize a cost-effective active filtering solution for nonlinear loads in the range of megawatt and above. The DHAF system achieves harmonic isolation at dominant harmonic frequencies, e.g. the 5th and 7th. This approach allows use of low switching frequency and small rating active filter inverters (1%--2% of the load MVA rating) for implementation. Review of conventional passive filters and various active filters based on high bandwidth PWM inverters is provided. The control theory of the DHAF system is presented. Comparison of the DHAF system and other dominant harmonic filtering approach is provided. Simulation results and laboratory prototype test results are presented to validate the effectiveness of the proposed DHAF system.

  5. Significance of High-frequency Electrical Brain Activity.

    Science.gov (United States)

    Kobayashi, Katsuhiro; Akiyama, Tomoyuki; Agari, Takashi; Sasaki, Tatsuya; Shibata, Takashi; Hanaoka, Yoshiyuki; Akiyama, Mari; Endoh, Fumika; Oka, Makio; Date, Isao

    2017-06-01

     Electroencephalogram (EEG) data include broadband electrical brain activity ranging from infra-slow bands (frequency bands (e.g., the approx. 10 Hz alpha rhythm) to high-frequency bands of up to 500 Hz. High-frequency oscillations (HFOs) including ripple and fast ripple oscillations (80-200 Hz and>200 / 250 Hz, respectively) are particularly of note due to their very close relationship to epileptogenicity, with the possibility that they could function as a surrogate biomarker of epileptogenicity. In contrast, physiological high-frequency activity plays an important role in higher brain functions, and the differentiation between pathological / epileptic and physiological HFOs is a critical issue, especially in epilepsy surgery. HFOs were initially recorded with intracranial electrodes in patients with intractable epilepsy as part of a long-term invasive seizure monitoring study. However, fast oscillations (FOs) in the ripple and gamma bands (40-80 Hz) are now noninvasively detected by scalp EEG and magnetoencephalography, and thus the scope of studies on HFOs /FOs is rapidly expanding.

  6. Highly Active Rare-Earth-Metal La-Doped Photocatalysts: Fabrication, Characterization, and Their Photocatalytic Activity

    Directory of Open Access Journals (Sweden)

    S. Anandan

    2012-01-01

    Full Text Available Efficient La-doped TiO2 photocatalysts were prepared by sol-gel method and extensively characterized by various sophisticated techniques. The photocatalytic activity of La-doped TiO2 was evaluated for the degradation of monocrotophos (MCPs in aqueous solution. It showed higher rate of degradation than pure TiO2 for the light of wavelength of 254 nm and 365 nm. The rate constant of TiO2 increases with increasing La loading and exhibits maximum rate for 1% La loading. The photocatalytic activities of La-doped TiO2 are compared with La-doped ZnO; the reaction rate of the former is ~1.8 and 1.1 orders higher than the latter for the lights of wavelength 254 nm and 365 nm, respectively. The relative photonic efficiency of La-doped TiO2 is relatively higher than La-doped ZnO and commercial photocatalysts. Overall, La-doped TiO2 is the most active photocatalyst and shows high relative photonic efficiencies and high photocatalytic activity for the degradation of MCP. The enhanced photocatalytic activity of La-doped TiO2 is mainly due to the electron trapping by lanthanum metal ions, small particle size, large surface area, and high surface roughness of the photocatalysts.

  7. Sulfurized activated carbon for high energy density supercapacitors

    Science.gov (United States)

    Huang, Yunxia; Candelaria, Stephanie L.; Li, Yanwei; Li, Zhimin; Tian, Jianjun; Zhang, Lili; Cao, Guozhong

    2014-04-01

    Sulfurized activated carbon (SAC), made by coating the pore surface with thiophenic sulfur functional groups from the pyrolysis of sulfur flakes, were characterized and tested for supercapacitor applications. From X-ray photoelectron spectroscopy (XPS), the sulfur content in the SAC was found to be 2.7 at%. Electrochemical properties from potentiostatic and galvanostatic measurements, and electrochemical impedance spectroscopy (EIS) were used to evaluate the effect of sulfur on porous carbon electrodes. The SAC electrode exhibits better conductivity, and an obvious increase in specific capacitance that is almost 40% higher than plain activated carbons (ACs) electrode at a high current density of 1.4 A g-1. The proposed mechanism for improved conductivity and capacitive performance due to the sulfur functional groups on ACs will be discussed.

  8. Easy and Rapid Purification of Highly Active Nisin

    Directory of Open Access Journals (Sweden)

    André Abts

    2011-01-01

    Full Text Available Nisin is an antimicrobial peptide produced and secreted by several L. lactis strains and is specifically active against Gram-positive bacteria. In previous studies, nisin was purified via cation exchange chromatography at low pH employing a single-step elution using 1 M NaCl. Here, we describe an optimized purification protocol using a five-step NaCl elution to remove contaminants. The obtained nisin is devoid of impurities and shows high bactericidal activity against the nisin-sensitive L. lactis strain NZ9000. Purified nisin exhibits an IC50 of ~3 nM, which is a tenfold improvement as compared to nisin obtained via the one-step elution procedure.

  9. Magneto-Optical Activity in High Index Dielectric Nanoantennas

    CERN Document Server

    de Sousa, N; Sáenz, J J; García-Martín, A

    2016-01-01

    The magneto-optical activity, namely the polarization conversion capabilities of high-index, non-absorbing, core-shell dielectric nanospheres is theoretically analyzed. We show that, in analogy with their plasmonic counterparts, the polarization conversion in resonant dielectric particles is linked to the amount of electromagnetic field probing the magneto-optical material in the system. However, in strong contrast with plasmon nanoparticles, due to the peculiar distribution of the internal fields in resonant dielectric spheres, the magneto-optical response is fully governed by the magnetic (dipolar and quadrupolar) resonances with little effect of the electric ones.

  10. Highly Active Carbene Ruthenium Catalyst for Metathesis of 1-Hexene

    Institute of Scientific and Technical Information of China (English)

    BAI Chen-Xi; ZHANG Zhi-Qiang; L(U) Xiao-Bing; HE Ren; ZHANG Wen-Zhen; LU Shu-Lai

    2006-01-01

    A new carbene ruthenium complex, 1,3-bis(2,6-dimethylphenyl)-4,5-dihydroimidazol-2-ylidene)(PPh3)Cl2-Ru=CHPh, was synthesized and used as catalyst for the metathesis of 1-hexene. The resulting complex exhibited very high catalytic activity whose TOF is up to 6680 h-1. However, at the same time significant olefin isomerization was observed and could be surpressed by changing reaction conditions, such as temperature, time, alkene/Ru molar ratio and solvent.

  11. Production of N-13 labeled compounds with high specific activity

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Kazutoshi; Sasaki, Motoji; Yoshida, Yuichiro; Haradahira, Terushi; Inoue, Osamu [National Inst. of Radiological Sciences, Chiba (Japan)

    1997-03-01

    Nitrogen-13 was produced by irradiating ultra pure water saturated with a pure gas (N2, O2, He, H2) with 18 MeV protons. Ion species generated by irradiation were analyzed with radio ion chromatography systems. An automated equipment was developed to synthesize anhydrous (13N)NH3 as a synthetic precursor and (13N)p-nitrophenyl carbamate ((13N)NPC) as a model compound, using the (13N)NH3. The radiochemical yield and specific activity of (13N)NPC was high enough to carry out the receptor study with PET. (author)

  12. High dielectric constant, low loss and high photocatalytic activity in Gd doped ZnO systems

    Science.gov (United States)

    Divya, N. K.; Pradyumnan, P. P.

    2017-01-01

    Enhanced photocatalytic activity and high dielectric constant values are achieved by gadolinium (Gd) doping in ZnO. The changes that happened to the wurtzite structure of ZnO on doping are depicted in detail by using x-ray diffraction spectroscopy. The chemical composition is confirmed using energy dispersive x-ray spectroscopy (EDAX). The influence of Gd incorporation in the emission spectra of ZnO is analysed from photoluminescence studies. The photocatalytic activity enhancement occurred in ZnO system on Gd doping was explored by kinetic rate analysis. The optimum incorporation of Gd has enhanced the dielectric constant value and decreased the loss of pristine. The high dielectric constant value and low loss make the system suitable for large scale of applications in microelectronics. The work also proposes large scale synthesis of highly efficient fluorescent Gd doped ZnO photocatalysts.

  13. Highly active ozonides selected against drug resistant malaria

    Science.gov (United States)

    Lobo, Lis; de Sousa, Bruno; Cabral, Lília; Cristiano, Maria LS; Nogueira, Fátima

    2016-01-01

    Ever increasing multi-drug resistance by Plasmodium falciparum is creating new challenges in malaria chemotherapy. In the absence of licensed vaccines, treatment and prevention of malaria is heavily dependent on drugs. Potency, range of activity, safety, low cost and ease of administration are crucial issues in the design and formulation of antimalarials. We have tested three synthetic ozonides NAC89, LC50 and LCD67 in vitro and in vivo against multidrug resistant Plasmodium. In vitro, LC50 was at least 10 times more efficient inhibiting P. falciparum multidrug resistant Dd2 strain than chloroquine and mefloquine and as efficient as artemisinin (ART), artesunate and dihydroartemisinin. All three ozonides showed high efficacy in clearing parasitaemia in mice, caused by multi-drug resistant Plasmodium chabaudi strains, by subcutaneous administration, demonstrating high efficacy in vivo against ART and artesunate resistant parasites. PMID:27276364

  14. Highly active ozonides selected against drug resistant malaria

    Directory of Open Access Journals (Sweden)

    Lis Lobo

    2016-01-01

    Full Text Available Ever increasing multi-drug resistance by Plasmodium falciparum is creating new challenges in malaria chemotherapy. In the absence of licensed vaccines, treatment and prevention of malaria is heavily dependent on drugs. Potency, range of activity, safety, low cost and ease of administration are crucial issues in the design and formulation of antimalarials. We have tested three synthetic ozonides NAC89, LC50 and LCD67 in vitro and in vivo against multidrug resistant Plasmodium. In vitro, LC50 was at least 10 times more efficient inhibiting P. falciparum multidrug resistant Dd2 strain than chloroquine and mefloquine and as efficient as artemisinin (ART, artesunate and dihydroartemisinin. All three ozonides showed high efficacy in clearing parasitaemia in mice, caused by multi-drug resistant Plasmodium chabaudi strains, by subcutaneous administration, demonstrating high efficacy in vivo against ART and artesunate resistant parasites.

  15. Double-negative feedback between S-phase cyclin-CDK and CKI generates abruptness in the G1/S switch

    Directory of Open Access Journals (Sweden)

    Rainis eVenta

    2012-12-01

    Full Text Available The G1/S transition is a crucial decision point in the cell cycle. At G1/S, there is an abrupt switch from a state of high CDK inhibitor (CKI levels and low S-phase CDK activity to a state of high S-phase CDK activity and degraded CKI. In budding yeast, this transition is triggered by phosphorylation of the Cdk1 inhibitor Sic1 at multiple sites by G1-phase CDK (Cln1,2-Cdk1 and S-phase CDK (Clb5,6-Cdk1 complexes. Using mathematical modeling we demonstrate that the mechanistic basis for the abruptness and irreversibility of the G1/S transition is the highly specific phosphorylation of Sic1 by S-phase CDK complex. This switch is generated by a double negative feedback loop in which S-CDK1 phosphorylates Sic1, thus targeting it for destruction, and thereby liberating further S-CDK1 from the inhibitory Sic1-S-CDK1 complex. Our model predicts that the abruptness of the switch depends upon a strong binding affinity within the Sic1-S-CDK inhibitory complex. In vitro phosphorylation analysis using purified yeast proteins revealed that free Clb5-Cdk1 can create positive feedback by phosphorylating Sic1 that is bound in the inhibitory complex, and that Sic1 inhibits Clb5-Cdk1 with a sub-nanomolar inhibition constant. Our model also predicts that if the G1-phase CDK complex is too efficient at targeting Sic1 for destruction, then G1/S becomes a smooth and readily reversible transition. We propose that the optimal role for the G1-phase CDK in the switch would not be to act as a kinase activity directly responsible for abrupt degradation of CKI, but rather to act as a priming signal that initiates a positive feedback loop driven by emerging free S-phase CDK.

  16. Cell Cycle Regulators Guide Mitochondrial Activity in Radiation-Induced Adaptive Response

    Science.gov (United States)

    Alexandrou, Aris T.

    2014-01-01

    Abstract Significance: There are accruing concerns on potential genotoxic agents present in the environment including low-dose ionizing radiation (LDIR) that naturally exists on earth's surface and atmosphere and is frequently used in medical diagnosis and nuclear industry. Although its long-term health risk is being evaluated and remains controversial, LDIR is shown to induce temporary but significant adaptive responses in mammalian cells and animals. The mechanisms guiding the mitochondrial function in LDIR-induced adaptive response represent a unique communication between DNA damage and cellular metabolism. Elucidation of the LDIR-regulated mitochondrial activity may reveal new mechanisms adjusting cellular function to cope with hazardous environmental stress. Recent Advances: Key cell cycle regulators, including Cyclin D1/CDK4 and Cyclin B1/cyclin-dependent kinase 1 (CDK1) complexes, are actively involved in the regulation of mitochondrial functions via phosphorylation of their mitochondrial targets. Accumulating new evidence supports a concept that the Cyclin B1/CDK1 complex acts as a mediator in the cross talk between radiation-induced DNA damage and mitochondrial functions to coordinate cellular responses to low-level genotoxic stresses. Critical Issues: The LDIR-mediated mitochondrial activity via Cyclin B1/CDK1 regulation is an irreplaceable network that is able to harmonize vital cellular functions with adjusted mitochondrial metabolism to enhance cellular homeostasis. Future Directions: Further investigation of the coordinative mechanism that regulates mitochondrial activities in sublethal stress conditions, including LDIR, will reveal new insights of how cells cope with genotoxic injury and will be vital for future targeted therapeutic interventions that reduce environmental injury and cancer risk. Antioxid. Redox Signal. 20, 1463–1480. PMID:24180340

  17. Cell cycle regulators guide mitochondrial activity in radiation-induced adaptive response.

    Science.gov (United States)

    Alexandrou, Aris T; Li, Jian Jian

    2014-03-20

    There are accruing concerns on potential genotoxic agents present in the environment including low-dose ionizing radiation (LDIR) that naturally exists on earth's surface and atmosphere and is frequently used in medical diagnosis and nuclear industry. Although its long-term health risk is being evaluated and remains controversial, LDIR is shown to induce temporary but significant adaptive responses in mammalian cells and animals. The mechanisms guiding the mitochondrial function in LDIR-induced adaptive response represent a unique communication between DNA damage and cellular metabolism. Elucidation of the LDIR-regulated mitochondrial activity may reveal new mechanisms adjusting cellular function to cope with hazardous environmental stress. Key cell cycle regulators, including Cyclin D1/CDK4 and Cyclin B1/cyclin-dependent kinase 1 (CDK1) complexes, are actively involved in the regulation of mitochondrial functions via phosphorylation of their mitochondrial targets. Accumulating new evidence supports a concept that the Cyclin B1/CDK1 complex acts as a mediator in the cross talk between radiation-induced DNA damage and mitochondrial functions to coordinate cellular responses to low-level genotoxic stresses. The LDIR-mediated mitochondrial activity via Cyclin B1/CDK1 regulation is an irreplaceable network that is able to harmonize vital cellular functions with adjusted mitochondrial metabolism to enhance cellular homeostasis. Further investigation of the coordinative mechanism that regulates mitochondrial activities in sublethal stress conditions, including LDIR, will reveal new insights of how cells cope with genotoxic injury and will be vital for future targeted therapeutic interventions that reduce environmental injury and cancer risk.

  18. Great expectations: different high-risk activities satisfy different motives.

    Science.gov (United States)

    Barlow, Matthew; Woodman, Tim; Hardy, Lew

    2013-09-01

    Research on people's motives for engaging in high-risk activities has typically been viewed through the single-focused lens of sensation seeking. We provide evidence that comprehensively challenges that view. First, we develop and confirm the structure of a 3-factor measure of motives: the Sensation Seeking, Emotion Regulation, and Agency Scale (SEAS; Study 1). We then use the SEAS to provide evidence of differential motives for 2 high-risk activities: skydiving and mountaineering. The motive for skydiving is strongly associated with sensation seeking; the motive for mountaineering is strongly associated with emotion regulation and agency but not with sensation seeking (Study 2). We also show that these conclusions cannot be drawn from existing measures of personality and sensation seeking (Study 3). Finally, individuals who are motivated by emotion regulation and agency needs also have greater expectations regarding their emotion regulation and agency. It is these greater expectations that most successfully discriminate mountaineers from skydivers and control participants (Study 4). It is concluded that researchers should no longer consider risk takers as a homogenous sensation-seeking group and that they should consider risk taking as a potential model of human endeavor. The SEAS can be used as a measure of motives for behavior whenever sensation seeking, agency, or emotion regulation is thought to be at the core of such motives, and the results are discussed in the context of encouraging personality researchers to consider the specific spontaneous behaviors that motivate different people.

  19. Activated carbon fibers with a high heteroatom content by chemical activation of PBO with phosphoric acid.

    Science.gov (United States)

    Vázquez-Santos, M B; Suárez-García, F; Martínez-Alonso, A; Tascón, J M D

    2012-04-03

    The preparation of activated carbon fibers (ACFs) by phosphoric acid activation of poly(p-phenylene benzobisoxazole) (PBO) fibers was studied, with particular attention to the effects of impregnation ratio and carbonization temperature on porous texture. Phosphoric acid has a strong effect on PBO degradation, lowering the temperature range at which the decomposition takes place and changing the number of mass loss steps. Chemical analysis results indicated that activation with phosphoric acid increases the concentration of oxygenated surface groups; the resulting materials also exhibiting high nitrogen content. ACFs are obtained with extremely high yields; they have well-developed porosity restricted to the micropore and narrow mesopore range and with a significant concentration of phosphorus incorporated homogeneously in the form of functional groups. An increase in the impregnation ratio leads to increases in both pore volume and pore size, maximum values of surface area (1250 m(2)/g) and total pore volume (0.67 cm(3)/g) being attained at the highest impregnation ratio (210 wt % H(3)PO(4)) and lowest activation temperature (650 °C) used; the corresponding yield was as large as 83 wt %. The obtained surface areas and pore volumes were higher than those achieved in previous works by physical activation with CO(2) of PBO chars.

  20. Latitude migration of solar activity at high latitudes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Utilized here is the Carte Synoptique solar filament archive,namely the catalogue of solar filaments from March 1919 to December 1989,corresponding to solar rotation numbers 876 to 1823 to study Iatitudinal migration of solar activity at high Iatitudes.Except the well-known poleward migration of solar activity from middle Iatitudes to the poles,an equatorward migration is found from the solar poles toward middle Iatitudes(about 40°)within a normal cycle,which iS neglected before,and the time interval for the former migration(4.4 years)is about 2.2 years shorter than that for the latter(6.6 years),indicating that the change from one migration to the other takes place around the maximum time of a normal cycle.In the future,a dynamo model should represent the migration from the poles toward middle Iatitudes of the Sun,besides the migration in"butterfly diagrams"and the"rush to the poles".The traditional extended activity cycle is actually a part of the period of the successive migration from the poles toward the solar equator.

  1. High-frequency TRNS reduces BOLD activity during visuomotor learning.

    Directory of Open Access Journals (Sweden)

    Catarina Saiote

    Full Text Available Transcranial direct current stimulation (tDCS and transcranial random noise stimulation (tRNS consist in the application of electrical current of small intensity through the scalp, able to modulate perceptual and motor learning, probably by changing brain excitability. We investigated the effects of these transcranial electrical stimulation techniques in the early and later stages of visuomotor learning, as well as associated brain activity changes using functional magnetic resonance imaging (fMRI. We applied anodal and cathodal tDCS, low-frequency and high-frequency tRNS (lf-tRNS, 0.1-100 Hz; hf-tRNS 101-640 Hz, respectively and sham stimulation over the primary motor cortex (M1 during the first 10 minutes of a visuomotor learning paradigm and measured performance changes for 20 minutes after stimulation ceased. Functional imaging scans were acquired throughout the whole experiment. Cathodal tDCS and hf-tRNS showed a tendency to improve and lf-tRNS to hinder early learning during stimulation, an effect that remained for 20 minutes after cessation of stimulation in the late learning phase. Motor learning-related activity decreased in several regions as reported previously, however, there was no significant modulation of brain activity by tDCS. In opposition to this, hf-tRNS was associated with reduced motor task-related-activity bilaterally in the frontal cortex and precuneous, probably due to interaction with ongoing neuronal oscillations. This result highlights the potential of lf-tRNS and hf-tRNS to differentially modulate visuomotor learning and advances our knowledge on neuroplasticity induction approaches combined with functional imaging methods.

  2. High sulfation and a high molecular weight are important for anti-hepcidin activity of heparin

    Directory of Open Access Journals (Sweden)

    Michela eAsperti

    2016-01-01

    Full Text Available Heparins are efficient inhibitors of hepcidin expression even in vivo, where they induce an increase of systemic iron availability. Heparins seem to act by interfering with BMP6 signaling pathways that control the expression of liver hepcidin, causing the suppression of SMAD1/5/8 phosphorylation. The anti-hepcidin activity persists also when the heparin anticoagulant property is abolished or reduced by chemical reactions of oxidation/reduction (glycol-split, Gs-Heparins or by high sulfation (SS-Heparins, but the structural characteristics needed to optimize this inhibitory activity have not been studied in detail. To this aim we analyzed three different heparins (Mucosal Heparin, the Glycol split RO-82, the partially desulfated glycol-split RO-68 and the oversulfated SSLMWH and separated them in fractions of molecular weight in the range 4-16 kD. Since the distribution of the negative charges in heparins contributes to the activity, we produced 2-O- and 6-O-desulfated heparins. These derivatives were analyzed for the capacity to inhibit hepcidin expression in hepatic HepG2 cells, in mice, and also for the capacity to bind an Heparin Binding Domain peptide. The three approaches produced consistent results and showed that the anti-hepcidin activity strongly decreases with molecular weight below 7 kD, with an increase of the N-acetylation level and after 2-O and 6-O desulfation. The high sulfation and high molecular weight properties for efficient anti-hepcidin activity suggest that heparin is involved in multiple binding sites.

  3. Enzymatic activity of Lecithin:retinol acyltransferase: a thermostable and highly active enzyme with a likely mode of interfacial activation.

    Science.gov (United States)

    Horchani, Habib; Bussières, Sylvain; Cantin, Line; Lhor, Mustapha; Laliberté-Gemme, Jean-Sébastien; Breton, Rock; Salesse, Christian

    2014-06-01

    Lecithin:retinol acyltransferase (LRAT) plays a major role in the vertebrate visual cycle. Indeed, it is responsible for the esterification of all-trans retinol into all-trans retinyl esters, which can then be stored in microsomes or further metabolized to produce the chromophore of rhodopsin. In the present study, a detailed characterization of the enzymatic properties of truncated LRAT (tLRAT) has been achieved using in vitro assay conditions. A much larger tLRAT activity has been obtained compared to previous reports and to an enzyme with a similar activity. In addition, tLRAT is able to hydrolyze phospholipids bearing different chain lengths with a preference for micellar aggregated substrates. It therefore presents an interfacial activation property, which is typical of classical phospholipases. Furthermore, given that stability is a very important quality of an enzyme, the influence of different parameters on the activity and stability of tLRAT has thus been studied in detail. For example, storage buffer has a strong effect on tLRAT activity and high enzyme stability has been observed at room temperature. The thermostability of tLRAT has also been investigated using circular dichroism and infrared spectroscopy. A decrease in the activity of tLRAT was observed beyond 70°C, accompanied by a modification of its secondary structure, i.e. a decrease of its α-helical content and the appearance of unordered structures and aggregated β-sheets. Nevertheless, residual activity could still be observed after heating tLRAT up to 100°C. The results of this study highly improved our understanding of this enzyme. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Novel antimicrobial peptides with high anticancer activity and selectivity.

    Directory of Open Access Journals (Sweden)

    Hung-Lun Chu

    Full Text Available We describe a strategy to boost anticancer activity and reduce normal cell toxicity of short antimicrobial peptides by adding positive charge amino acids and non-nature bulky amino acid β-naphthylalanine residues to their termini. Among the designed peptides, K4R2-Nal2-S1 displayed better salt resistance and less toxicity to hRBCs and human fibroblast than Nal2-S1 and K6-Nal2-S1. Fluorescence microscopic studies indicated that the FITC-labeled K4R2-Nal2-S1 preferentially binds cancer cells and causes apoptotic cell death. Moreover, a significant inhibition in human lung tumor growth was observed in the xenograft mice treated with K4R2-Nal2-S1. Our strategy provides new opportunities in the development of highly effective and selective antimicrobial and anticancer peptide-based therapeutics.

  5. VTEC behavior in the American sector during high solar activity

    CERN Document Server

    Ezquer, R G; Brunini, C; Conicet; Meza, A; Mosert, M; Radicella, S M

    2002-01-01

    The behavior of the vertical total electron content (VTEC) obtained from GPS signals received during the high solar activity year 1999 at stations placed in the American sector, is reported. The considered latitude range extends from 18.4 to -64.7 and the longitude ranges from 281.3 to 297.7. Median, lower and upper quartiles are used to specify variability, because they have the advantage of being less affected by large deviations that can occur during magnetic storms. The results show that the VTEC values corresponding to equinox are greater than those of solstice and that, the highest VTEC values are observed at low latitude stations. In general, the variability during daylight hours is about 30% of median or less, and that observed for nighttime hours is greater than the mentioned percentage, particularly at last hours of the night near the northern peak of the equatorial anomaly.

  6. Using Highly Interactive Virtual Environments for Safeguards Activities

    Energy Technology Data Exchange (ETDEWEB)

    Weil, Bradley S [ORNL; Alcala, Benjamin S [ORNL; Alcala, Scott [ORNL; Eipeldauer, Mary D [ORNL; Weil, Logan B [ORNL

    2010-01-01

    Highly interactive virtual environment (HIVE) is a term that refers to interactive educational simulations, serious games and virtual worlds. Studies indicate that learning with the aid of interactive environments produces better retention and depth of knowledge by promoting improved trainee engagement and understanding. Virtual reality or three dimensional (3D) visualization is often used to promote the understanding of something when personal observation, photographs, drawings, and/or sketches are not possible or available. Subjects and situations, either real or hypothetical, can be developed using a 3D model. Models can be tailored to the audience allowing safeguards and security features to be demonstrated for educational purposes in addition to engineering evaluation and performance analysis. Oak Ridge National Laboratory (ORNL) has begun evaluating the feasibility of HIVEs for improving safeguards activities such as training, mission planning, and evaluating worker task performance. This paper will discuss the development workflow of HIVEs and present some recent examples.

  7. High-resolution infrared observations of active galactic nuclei

    Science.gov (United States)

    Pott, Jörg-Uwe

    2012-07-01

    Interferometric resolution at IR wavelengths offers for the first time the possibility to zoom into the nuclei of galaxies beyond the circumnuclear stellar structures and spatially resolve gas and dust in the innermost regions (0.05-5pc), dominated by the central black hole. Ultimate goal is to reveal new aspects of AGN feeding, and interaction with its host galaxy. After first successes of resolving AGN with infrared interferometry (VLTI, Keck-IF), the second generation of high-resolution interferometric imagers behind 8m class telescopes is currently being built. I will summarize current aspects and successes of the field, and present our activities to provide extended capabilities for VLTI-Midi and -Matisse, LBT-Linc-Nirvana and Keck-Astra to study a larger sample of AGN in greater detail.

  8. High resolution dynamical mapping of social interactions with active RFID

    CERN Document Server

    Barrat, Alain; Colizza, Vittoria; Pinton, Jean-Francois; Broeck, Wouter Van den; Vespignani, Alessandro

    2008-01-01

    In this paper we present an experimental framework to gather data on face-to-face social interactions between individuals, with a high spatial and temporal resolution. We use active Radio Frequency Identification (RFID) devices that assess contacts with one another by exchanging low-power radio packets. When individuals wear the beacons as a badge, a persistent radio contact between the RFID devices can be used as a proxy for a social interaction between individuals. We present the results of a pilot study %recently performed during a conference, and a subsequent preliminary data analysis, that provides an assessment of our method and highlights its versatility and applicability in many areas concerned with human dynamics.

  9. A Case of Hyperammonemia Associated with High Dihydropyrimidine Dehydrogenase Activity

    Directory of Open Access Journals (Sweden)

    Keiki Nagaharu

    2016-01-01

    Full Text Available Over the past decades, 5-Fluorouracil (5-FU has been widely used to treat several types of carcinoma, including esophageal squamous cell carcinoma. In addition to its common side effects, including diarrhea, mucositis, neutropenia, and anemia, 5-FU treatment has also been reported to cause hyperammonemia. However, the exact mechanism responsible for 5-FU-induced hyperammonemia remains unknown. We encountered an esophageal carcinoma patient who developed hyperammonemia when receiving 5-FU-containing chemotherapy but did not exhibit any of the other common adverse effects of 5-FU treatment. At the onset of hyperammonemia, laboratory tests revealed high dihydropyrimidine dehydrogenase (DPD activity and rapid 5-FU clearance. Our findings suggested that 5-FU hypermetabolism may be one of the key mechanisms responsible for hyperammonemia during 5-FU treatment.

  10. Solvothermal syntheses of semiconductor photocatalysts of ultra-high activities

    Energy Technology Data Exchange (ETDEWEB)

    Kominami, Hiroshi; Kato, Jun-ichi; Murakami, Shin-ya; Ishii, Yoshinori; Kohno, Masaaki; Yabutani, Kei-ichi; Yamamoto, Takuhei; Kera, Yoshiya [Department of Applied Chemistry, Faculty of Science and Engineering, Kinki University, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Inoue, Masashi; Inui, Tomoyuki [Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Kyoto 606-8501 (Japan); Ohtani, Bunsho [Catalysis Research Center, Hokkaido University, Sapporo 060-0811 (Japan)

    2003-09-15

    Thermal treatment of titanium(IV) butoxide dissolved in 2-butanol at 573K under autogenous pressure (alcohothermal treatment) yielded microcrystalline anatase-type titanium(IV) oxide (TiO{sub 2}). Thermal treatment of oxobis(2,4-pentanedionato-O,O')titanium (TiO(acac){sub 2}) in ethylene glycol (EG) in the presence of sodium acetate and a small amount of water at 573K yielded microcrystalline brookite-type TiO{sub 2}. Tungsten(VI) oxide (WO{sub 3}) powders of monoclinic crystal structure with high crystallinity were synthesized by hydrothermal treatment (HTT), at 523 or 573K, of aqueous tungstic acid (H{sub 2}WO{sub 4}) solutions prepared from sodium tungstate by ion-exchange (IE) with a proton-type resin. Anatase and brookite TiO{sub 2} products were calcined at various temperatures and then used for photocatalytic mineralization of acetic acid in aqueous solutions under aerated conditions and dehydrogenation of 2-propanol under deaerated conditions. Almost all the anatase-type TiO{sub 2} samples showed the activities more than twice higher than those of representative active photocatalysts, Degussa P-25 and Ishihara ST-01 in both reactions. A brookite sample with improved crystallinity and sufficient surface area obtained by calcination at 973K exhibited the hydrogen evolution rate almost equal to P-25. HTT WO{sub 3} powders with various physical properties were used as photocatalyst for evolution of oxygen (O{sub 2}) from an aqueous silver sulfate solution. WO{sub 3} powder of high crystallinity, e.g., IE-HTT-WO{sub 3} synthesized at 573K, gave much higher O{sub 2} yield than commercially available WO{sub 3} samples.

  11. Sensor fusion methods for high performance active vibration isolation systems

    Science.gov (United States)

    Collette, C.; Matichard, F.

    2015-04-01

    Sensor noise often limits the performance of active vibration isolation systems. Inertial sensors used in such systems can be selected through a wide variety of instrument noise and size characteristics. However, the most sensitive instruments are often the biggest and the heaviest. Consequently, high-performance active isolators sometimes embed many tens of kilograms in instrumentation. The weight and size of instrumentation can add unwanted constraint on the design. It tends to lower the structures natural frequencies and reduces the collocation between sensors and actuators. Both effects tend to reduce feedback control performance and stability. This paper discusses sensor fusion techniques that can be used in order to increase the control bandwidth (and/or the stability). For this, the low noise inertial instrument signal dominates the fusion at low frequency to provide vibration isolation. Other types of sensors (relative motion, smaller but noisier inertial, or force sensors) are used at higher frequencies to increase stability. Several sensor fusion configurations are studied. The paper shows the improvement that can be expected for several case studies including a rigid equipment, a flexible equipment, and a flexible equipment mounted on a flexible support structure.

  12. Highly active and efficient catalysts for alkoxycarbonylation of alkenes

    Science.gov (United States)

    Dong, Kaiwu; Fang, Xianjie; Gülak, Samet; Franke, Robert; Spannenberg, Anke; Neumann, Helfried; Jackstell, Ralf; Beller, Matthias

    2017-01-01

    Carbonylation reactions of alkenes constitute the most important industrial processes in homogeneous catalysis. Despite the tremendous progress in this transformation, the development of advanced catalyst systems to improve their activity and widen the range of feedstocks continues to be essential for new practical applications. Herein a palladium catalyst based on 1,2-bis((tert-butyl(pyridin-2-yl)phosphanyl)methyl)benzene L3 (pytbpx) is rationally designed and synthesized. Application of this system allows a general alkoxycarbonylation of sterically hindered and demanding olefins including all kinds of tetra-, tri- and 1,1-disubstituted alkenes as well as natural products and pharmaceuticals to the desired esters in excellent yield. Industrially relevant bulk ethylene is functionalized with high activity (TON: >1,425,000 TOF: 44,000 h-1 for initial 18 h) and selectivity (>99%). Given its generality and efficiency, we expect this catalytic system to immediately impact both the chemical industry and research laboratories by providing a practical synthetic tool for the transformation of nearly any alkene into a versatile ester product.

  13. Exotic high activity surface patterns in PtAu nanoclusters

    KAUST Repository

    Mokkath, Junais Habeeb

    2013-05-09

    The structure and chemical ordering of PtAu nanoclusters of 79, 135, and 201 atoms are studied via a combination of a basin hopping atom-exchange technique (to locate the lowest energy homotops at fixed composition), a symmetry orbit technique (to find the high symmetry isomers), and density functional theory local reoptimization (for determining the most stable homotop). The interatomic interactions between Pt and Au are derived from the empirical Gupta potential. The lowest energy structures show a marked tendency toward PtcoreAushell chemical ordering by enrichment of the more cohesive Pt in the core region and of Au in the shell region. We observe a preferential segregation of Pt atoms to (111) facets and Au atoms to (100) facets of the truncated octahedron cluster motif. Exotic surface patterns are obtained particularly for Pt-rich compositions, where Pt atoms are being surrounded by Au atoms. These surface arrangements boost the catalytic activity by creating a large number of active sites. © 2013 American Chemical Society.

  14. On the Evolution of High-Redshift Active Galactic Nuclei

    CERN Document Server

    Mao, Jirong

    2016-01-01

    We build a simple physical model to study the high-redshift active galactic Nucleus (AGN) evolution within the co-evolution framework of central black holes (BHs) and their host galaxies. The correlation between the circular velocity of a dark halo $V_c$ and the velocity dispersion of a galaxy $\\sigma$ is used to link the dark matter halo mass and BH mass. The dark matter halo mass function is converted to the BH mass function for any given redshift. The high-redshift optical AGN luminosity functions (LFs) are constructed. At $z\\sim 4$, the flattening feature is not shown at the faint end of the optical AGN LF. This is consistent with observational results. If the optical AGN LF at $z\\sim 6$ can be reproduced in the case in which central BHs have the Eddington-limited accretion, it is possible for the AGN lifetime to have a small value of $2\\times 10^5$ yrs. The X-ray AGN LFs and X-ray AGN number counts are also calculated at $2.03$, respectively, using the same parameters adopted in the calculation for the o...

  15. Highly active antiretroviral therapy: Does it Sound toxic?

    Directory of Open Access Journals (Sweden)

    Katijah Khoza-Shangase

    2011-01-01

    Full Text Available Objective : The main objective of the current study is to monitor the auditory status in a group of adults with AIDS, receiving Highly Active Antiretroviral Therapy (HAART (3TC -lamivudine, D4T - stavudine, and efavirenz in a hospital outpatient clinic in Gauteng. A total sample of 54 adults (between the ages of 18 and 50 years in the experimental group and 16 in the control group were assessed prospectively following a repeated measures design. All participants were assessed at baseline at three months, and at six months into the treatment. Materials and Methods : The participants underwent case history interviews and medical record reviews, otoscopy, and tympanometry, as well as conventional pure tone audiometry and distortion product otoacoustic emission testing. Both descriptive and inferential statistics were used to analyze the data. Results : On audiological monitoring, statistically significant changes (P<0.05 were established, only in the experimental group, for pure tone audiometry - with clinically significant changes found at high frequencies. Statistically significant changes with clinically significant changes were obtained for distortion product otoacoustic emissions (DPOAEs in the experimental group, particularly at high frequencies - implying subclinical hearing function changes; while lack of statistically significant changes with no clinically significant changes were found in the control group. The subclinical hearing changes in the experimental group were also evident in the findings of the subclinical hearing loss group, who, although they had normal pure tone function after six months of follow up, presented with clinical changes on DPOAEs at 6 and 8 kHz. Conclusions : Findings highlight the need for closer monitoring of the effects of antiretroviral drugs (ARVs on hearing, through the use of more sensitive tools of assessment when conducting drug trials.

  16. Preparation of activated carbon with high surface area for high-capacity methane storage

    Institute of Scientific and Technical Information of China (English)

    Bingsi Liua; Wenshuo Wanga; Na Wanga; Peter Chak Tong Aub

    2014-01-01

    Activated carbon (AC) was fabricated from corncob, which is cheap and abundant. Experimental parameters such as particle size of corncob, KOH/char weight ratio, and activation temperature and time were optimized to generate AC, which shows high methane sorption capacity. AC has high specific surface area (3227 m2/g), with pore volume and pore size distribution equal to 1.829 cm3/g and ca. 1.7-2.2 nm, respectively. Under the condition of 2◦C and less than 7.8 MPa, methane sorption in the presence of water (Rw=1.4) was as high as 43.7 wt%methane per unit mass of dry AC. The result is significantly higher than those of coconut-derived AC (32 wt%) and ordered mesoporous carbon (41.2 wt%, Rw=4.07) under the same condition. The physical properties and amorphous chaotic structure of AC were characterized by N2 adsorption isotherms, XRD, SEM and HRTEM. Hence, the corncob-derived AC can be considered as a competitive methane-storage material for vehicles, which are run by natural gas.

  17. Evidence of solar induced cycles of high seismic activity

    Science.gov (United States)

    Duma, G.

    2010-12-01

    In the past century, several observational results and corresponding publications indicate a systematic seismic performance with respect to the time of day and seasons as well. Such effects could be caused only by solar or lunar influence. In addition, a possible relation with the solar cycles was discussed in some papers, too. Intensive studies on these topics have also been performed at the Central Institute for Meteorology and Geodynamics (ZAMG), Vienna, Austria. They strongly confirm the above mentioned effects. In order to verify a solar influence on earthquake activity correlations were performed between the three-hour magnetic index Kp and the energy release of earthquakes in the long term. Kp characterizes the magnetic field disturbances which are mainly caused by the solar particle radiation, the solar wind. Kp is determined on a routine basis from magnetic records of 13 observatories worldwide and is continuously published by ISGI, France. Three regions of continental size were investigated, using the USGS (PDE) earthquake catalogue data, from 1974 on: N-America, S-America and Eurasia. The statistic analyses reveal that from 1974 to 2009 the index Kp varies in cycles with periods between 9 and 12 years, somewhat different to the sunspot number cycles (no. 21, 22, 23) of 11 years. As to the seismic energy release, the sqrt (energy E) of an event is taken as measure, which relates to the ‘strain release’ due to the earthquake (Benioff). For Kp the monthly averages were computed, for the strain release the monthly sums of sqrt(E), hereinafter referred to as STR. From the statistic estimates of the relation Kp-STR for all the three regions N-America, S-America and Eurasia it becomes evident, that the correlation is highly significant: earthquake activity, quantified by the monthly STR, follows the Kp cycles with high coincidence. A quantitative analysis reveals that on an annual basis, the sum of released energy by earthquakes changes by a factor up to

  18. High Efficiency Interleaved Active Clamped Dc-Dc Converter with Fuel Cell for High Voltage Applications

    Directory of Open Access Journals (Sweden)

    Sona P

    2014-02-01

    Full Text Available A high efficiency interleaved ZVS active clamped current fed dc-dc converter is proposed in this paper specially used for fuel cell applications. As the fuel cell output is very low we are in need of a step up dc-dc converter. Here a current fed dc-dc converter is used. Two current fed dc-dc converters are interleaved by connecting their inputs in parallel and outputs in series. With this proposed methodology input current ripples in the fuel cell stacks can be reduced and a regulated output voltage ripples can be obtained. The active clamping circuit used in this model absorbs the turn off voltage spikes hence low voltage devices with low on state resistance can be used.Voltage doubler circuits will give double the output voltage than normal with smaller transformer turns ratio and flexibility. The proposed method is simulated in MATLAB for verifying the accuracy of the proposed design.

  19. On the Evolution of High-redshift Active Galactic Nuclei

    Science.gov (United States)

    Mao, Jirong; Kim, Minsun

    2016-09-01

    We build a simple physical model to study the high-redshift active galactic nucleus (AGN) evolution within the co-evolution framework of central black holes (BHs) and their host galaxies. The correlation between the circular velocity of a dark halo V c and the velocity dispersion of a galaxy σ is used to link the dark matter halo mass and BH mass. The dark matter halo mass function is converted to the BH mass function for any given redshift. The high-redshift optical AGN luminosity functions (LFs) are constructed. At z˜ 4, the flattening feature is not shown at the faint end of the optical AGN LF. This is consistent with observational results. If the optical AGN LF at z˜ 6 can be reproduced in the case in which central BHs have the Eddington-limited accretion, it is possible for the AGN lifetime to have a small value of 2× {10}5 {{years}}. The X-ray AGN LFs and X-ray AGN number counts are also calculated at 2.0\\lt z\\lt 5.0 and z\\gt 3, respectively, using the same parameters adopted in the calculation for the optical AGN LF at z˜ 4. It is estimated that about 30 AGNs per {{{\\deg }}}2 at z\\gt 6 can be detected with a flux limit of 3× {10}-17 {erg} {{cm}}-2 {{{s}}}-1 in the 0.5-2 keV band. Additionally, the cosmic reionization is also investigated. The ultraviolet photons emitted from the high-redshift AGNs mainly contribute to the cosmic reionization, and the central BHs of the high-redshift AGNs have a mass range of {10}6{--}{10}8{M}⊙ . We also discuss some uncertainties in both the AGN LFs and AGN number counts originating from the {M}{{BH}}{--}σ relation, Eddington ratio, AGN lifetime, and X-ray attenuation in our model.

  20. Highly antioxidant carotene-lipid nanocarriers: synthesis and antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Lacatusu, Ioana; Badea, Nicoleta, E-mail: nicoleta.badea@gmail.com; Ovidiu, Oprea [University POLITEHNICA of Bucharest, Faculty of Applied Chemistry and Materials Science (Romania); Bojin, Dionezie [Faculty of Engineering and Materials Science (Romania); Meghea, Aurelia [University POLITEHNICA of Bucharest, Faculty of Applied Chemistry and Materials Science (Romania)

    2012-06-15

    The objective of this study was to explore the potential of two natural oils (squalene-Sq and grape seed oil-GSO) to prepare biocompatible antioxidant nanostructured lipid carriers-NLCs as a safety and protective formulation for sensitive {beta}-carotene. For this purpose different oil-in-water nanoemulsions stabilized by a combination of alkylpolyoxy ethylene sorbitans, lecithin and a block copolymer, were prepared using a melt high-shear homogenization process. The physico-chemical characteristics of the carotene-loaded NLCs were firstly investigated in detail. The smaller lipid nanoparticles have been obtained by using Tween 20 as main non-ionic surfactant, with average diameters of about 85 nm for GSO and 89 nm for Sq, with a polydispersity index <0.19. The developed carotene-NLCs presented an excellent physical stability with almost all zeta potential values ranging between -29 Division-Sign -40 mV. The differential scanning calorimetry analysis showed that the {beta}-carotene incorporation has led to a perturbation of solid lipid matrix with a less ordered arrangement. By UV-Vis spectroscopy it was evidenced that after encapsulation {beta}-carotene adopts a supramolecular structure demonstrated by appearance of a shoulder at 530 nm related to a {beta}-carotene triplet-triplet absorption. The carotene-NLCs have been also evaluated in terms of in vitro antioxidant properties. The presence of Sq and GSO produced a significant effect on the antioxidant capacity of developed NLCs. The samples prepared with GSO and Tween 80 as main surfactant showed the highest antioxidant activity (AA %) against free oxygen radicals, exhibiting an enhancement of 35 % for loaded NLCs, as comparing to pure carotene. In addition to these properties, the ability of NLCs to manifest antibacterial activity was tested against Escherichiacoli bacteria. The antibacterial analysis shown that loaded-NLCs develop an effective inhibition zone against bacteria growth and it was dependent in a

  1. Synthesis and antiproliferative activity of substituted 3[2-(1H-indol-3-yl)- 1,3-thiazol-4-yl]-1H-pyrrolo[3,2-b]pyridines, marine alkaloid nortopsentin analogues.

    Science.gov (United States)

    Carbone, A; Pennati, M; Barraja, P; Montalbano, A; Parrino, B; Spanò, V; Lopergolo, A; Sbarra, S; Doldi, V; Zaffaroni, N; Cirrincione, G; Diana, P

    2014-01-01

    A large number of indolyl-4-azaindolyl thiazoles, nortopsentin analogues, were conveniently synthesized. The antiproliferative activity of the new derivatives was examined against four human tumor cell lines with different histologic origin. Seven derivatives consistently reduced the growth of the experimental models independently of TP53 gene status and exhibited the highest activity against the malignant peritoneal mesothelioma (STO) cell line. The most active compound of this series acts as a CDK1 inhibitor, and was found to cause cell cycle arrest at G2/M phase, to induce apoptosis by preventing the phosphorylation of survivin in Thr(34) and to increase the cytotoxic activity of paclitaxel in STO cells.

  2. Highly active nanocrystalline TiO(2) photoelectrodes.

    Science.gov (United States)

    Paronyan, Tereza M; Kechiantz, A M; Lin, M C

    2008-03-19

    A simple method for the fabrication of highly photoactive nanocrystalline two-layer TiO(2) electrodes for solar cell applications is presented. Diluted titanium acetylacetonate has been used as a precursor for covering SnO(2):F (FTO) films with dense packed TiO(2) nanocrystallites. The nanoporous thick TiO(2) film follows the dense packed thin TiO(2) film as a second layer. For the latter, amorphous TiO(2) nanoparticles have been successfully synthesized by a sol-gel technique in an acidic environment with pHTiO(2) gel of pH 5 was obtained; this pH value is higher than the recently reported value of 3.1 (Park et al 2005 Adv. Mater. 17 2349-53). Highly interconnected, nanoporous, transparent and active TiO(2) films have been fabricated from the pH 5 gel. SEM, AFM and XRD analyses have been carried out for investigation of the crystal structure and the size of nanoparticles as well as the surface morphology of the films. Investigation of the photocurrent-voltage characteristics has shown improvement in cell performance along with the modification of the surface morphology, depending on pH of the TiO(2) gel. Increasing the pH of the gel from 2.1 to 5 enhanced the overall conversion efficiency of the dye-sensitized solar cells by approximately 30%. An energy conversion efficiency of 8.83% has been achieved for the cell (AM1.5, 100  mWcm(-2) simulated sunlight) compared to 6.61% efficiency in the absence of ammonia in the TiO(2) gel.

  3. Highly active nanocrystalline TiO2 photoelectrodes

    Science.gov (United States)

    Paronyan, Tereza M.; Kechiantz, A. M.; Lin, M. C.

    2008-03-01

    A simple method for the fabrication of highly photoactive nanocrystalline two-layer TiO2 electrodes for solar cell applications is presented. Diluted titanium acetylacetonate has been used as a precursor for covering SnO2:F (FTO) films with dense packed TiO2 nanocrystallites. The nanoporous thick TiO2 film follows the dense packed thin TiO2 film as a second layer. For the latter, amorphous TiO2 nanoparticles have been successfully synthesized by a sol-gel technique in an acidic environment with pHacidic nanoparticle gel was neutralized by basic ammonia and a TiO2 gel of pH 5 was obtained; this pH value is higher than the recently reported value of 3.1 (Park et al 2005 Adv. Mater. 17 2349-53). Highly interconnected, nanoporous, transparent and active TiO2 films have been fabricated from the pH 5 gel. SEM, AFM and XRD analyses have been carried out for investigation of the crystal structure and the size of nanoparticles as well as the surface morphology of the films. Investigation of the photocurrent-voltage characteristics has shown improvement in cell performance along with the modification of the surface morphology, depending on pH of the TiO2 gel. Increasing the pH of the gel from 2.1 to 5 enhanced the overall conversion efficiency of the dye-sensitized solar cells by approximately 30%. An energy conversion efficiency of 8.83% has been achieved for the cell (AM1.5, 100 mWcm-2 simulated sunlight) compared to 6.61% efficiency in the absence of ammonia in the TiO2 gel.

  4. Active cooling of pulse compression diffraction gratings for high energy, high average power ultrafast lasers.

    Science.gov (United States)

    Alessi, David A; Rosso, Paul A; Nguyen, Hoang T; Aasen, Michael D; Britten, Jerald A; Haefner, Constantin

    2016-12-26

    Laser energy absorption and subsequent heat removal from diffraction gratings in chirped pulse compressors poses a significant challenge in high repetition rate, high peak power laser development. In order to understand the average power limitations, we have modeled the time-resolved thermo-mechanical properties of current and advanced diffraction gratings. We have also developed and demonstrated a technique of actively cooling Petawatt scale, gold compressor gratings to operate at 600W of average power - a 15x increase over the highest average power petawatt laser currently in operation. Combining this technique with low absorption multilayer dielectric gratings developed in our group would enable pulse compressors for petawatt peak power lasers operating at average powers well above 40kW.

  5. Removal of trichlorobenzene using 'oxygen-enriched' highly active absorbent.

    Science.gov (United States)

    Zhao, Yi; He, Peng; Zhang, Yu-Hai; Ma, Shuangchen

    2011-01-01

    Fly ash, industry lime and an additive, Ca(ClO2)2 (C) were used to prepare the 'oxygen-enriched' highly active absorbent (HAA). The influencing factors for removal of 1,2,4-trichlorobenzene (TCB) using this absorbent such as reaction temperature, simulating gas flow rate, oxygen content, etc. were studied in a self-designed reactor. The optimum experimental conditions of removing 1,2,4-TCB are that the content of an oxidizing additive in the absorbent is 3% (wt), simulating gas flow rate is 100 mL/min, reaction temperature is 250 degrees C, and the content of oxygen in simulating gas is 6%. The maximum removal efficiency is 81.71% in 10 mins. The absorption capacity of the absorbent is 0.000111 g/g. The reaction products were determined by gas chromatograph/mass spectrometer (GC/ MS), 2,6-Bis-[1,1-Dimethylethyl]-4-methyl-Phenol is considered to be the major intermediate product. The reaction route was revealed.

  6. Towards high-throughput microfluidic Raman-activated cell sorting.

    Science.gov (United States)

    Zhang, Qiang; Zhang, Peiran; Gou, Honglei; Mou, Chunbo; Huang, Wei E; Yang, Menglong; Xu, Jian; Ma, Bo

    2015-09-21

    Raman-activated cell sorting (RACS) is a promising single-cell analysis technology that is able to identify and isolate individual cells of targeted type, state or environment from an isogenic population or complex consortium of cells, in a label-free and non-invasive manner. However, compared with those widely used yet labeling-required or staining-dependent cell sorting technologies such as FACS and MACS, the weak Raman signal greatly limits the further development of the existing RACS systems to achieve higher throughput. Strategies that can tackle this bottleneck include, first, improvement of Raman-acquisition efficiency and quality based on advanced Raman spectrometers and enhanced Raman techniques; second, development of novel microfluidic devices for cell sorting followed by integration into a complete RACS system. Exploiting these strategies, prototypes for a new generation of RACS have been demonstrated, such as flow-based OT-RACS, DEP-RACS, and SERS/CARS flow cytometry. Such high-throughput microfluidic RACS can provide biologists with a powerful single-cell analysis tool to explore the scientific questions or applications that have been beyond the reach of FACS and MACS.

  7. Sclerosing cholangitis by cytomegalovirus in highly active antiretroviral therapy era

    Directory of Open Access Journals (Sweden)

    Carmen Hidalgo-Tenorio

    2013-10-01

    Full Text Available Sclerosing colangitis (SC due to cytomegalovirus (CMV is very rare. It has been described mainly in immunocompromised patients. Currently, in HIV infected patients it is exceptional. The most of cases belong to pre-highly active antiretroviral therapy (pre-HAART and those cases were in stage AIDS with less than 100 CD4/μl. The most frequently involved pathogen in pre-HAART period was Cryptosporidium parvum (30-57% and CMV (10-30%; in late HAART period this information are unaware. CMV has been implicated as a possible etiological agent in primary SC partly because of the ability to cause liver damage and its relationship with smooth muscle antibodies. The most effective treatment for SC was the combination of antiretroviral therapy and endoscopic retrograde cholangiopancreatography with sphincterotomy and stent placement. Following, we present the first case of late HAART period which describes a SC extrahepatic without papillary stenosis with CMV as the only cause and clinical presentation of HIV infection in a woman with 177 CD4/μl.

  8. Activation of fly ashes by the high temperature and high alkalinity in ASR tests

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    High temperature and high alkalinity are typical testing conditions to accelerate the appraisal process of the suppressing effect of fly ashes on alkali silica reaction(ASR),but the reaction mechanism of fly ashes would be quite different under such conditions compared to the normal condition of temperature and alkalinity.To make a reasonable analysis of the suppressing effect of fly ashes,13 types of fly ashes were tested in this paper by both the accelerated mortar bar test method and the 60°C accelerated concrete prism test method.The results showed that the effect of fly ashes would be magnified under the condition of high temperature and high alkalinity.The XRD analysis showed that all the phases of fly ash could react with the hot alkaline solution except for mullite and a small amount of quartz.Fly ash could be significantly activated by the 80°C 1 mol/L NaOH solution,and form mainly C-S-H phase and P type zeolite,but its effect on inhibiting ASR was exaggerated then.According to the mortar strength test and the ASR suppressing test results,C-S-H phase contributed to mortar strength,but its amount did not decide the ASR suppressing effect of fly ash.

  9. A tumor suppressor C53 protein antagonizes checkpoint kinases to promote cyclin-dependent kinase 1 activation

    OpenAIRE

    Jiang, Hai; Wu, Jianchun; He, Chen; Yang, Wending; Li, Honglin

    2009-01-01

    Cyclin dependent kinase 1 (Cdk1)/cyclin B1 complex is the driving force for mitotic entry, and its activation is tightly regulated by the G2/M checkpoint. We originally reported that a novel protein C53 (also known as Cdk5rap3 and LZAP) potentiates DNA damage-induced cell death by modulating the G2/M checkpoint (1). More recently, Wang et al (2007) found that C53/LZAP may function as a tumor suppressor via inhibiting NF-κB signaling (2). We report here identification of C53 protein as a novel...

  10. Objectively measured habitual physical activity in a highly obesogenic environment.

    Science.gov (United States)

    McLure, S A; Summerbell, C D; Reilly, J J

    2009-05-01

    While the prevalence of overweight and obesity among children continues to grow nationally, prevalence in the North-East of England is among the highest in the UK. The objective of this study was to investigate the habitual physical activity levels in a particularly obesogenic environment in the North-East of England. Eight primary schools were selected using a stratified random sampling frame ranking average deprivation levels. Participating children (n = 246, mean age 10 years) wore an accelerometer (Actigraph, GT-256) over five consecutive days (weekend plus three weekdays). Total daily moderate-to-vigorous intensity physical activity was calculated using thresholds by Puyau and colleagues. Only 7% (17/246) of children were sufficiently active. Boys were more physically active than girls (766 +/- 268 vs. 641 +/- 202 counts/min, 95% CI for the difference 63-186 cpm.). Total physical activity was not influenced significantly by deprivation levels or weight status, and there were no significant differences in physical activity between school or weekend days. The North-East of England is a recognized 'hot spot' for paediatric obesity and the present study shows that low levels of habitual physical activity are typical. Choice of accelerometry threshold affects both the apparent amount of physical activity and the ability to detect groups with particularly low levels of physical activity.

  11. Variety, Enjoyment, and Physical Activity Participation Among High School Students.

    Science.gov (United States)

    Michael, Shannon L; Coffield, Edward; Lee, Sarah M; Fulton, Janet E

    2016-02-01

    Federal guidelines state that youth should participate in a variety of physical activity (PA) they find enjoyable. Little is known, however, about how variety and enjoyment are associated with PA participation among adolescents. Data came from the 2010 National Youth Physical Activity and Nutrition Survey, a nationally representative survey of adolescents. Path analysis was used to examine the association of a variety of self-reported PA, defined as the number of activities and activity types (ie, team sports/weightlifting, individual activities, and other competitive/recreational sports), on self-reported PA enjoyment and participation. The analysis also examined whether enjoyment mediates the association between a variety of PA and participation. Separate models were estimated for boys and girls. Number of activities was associated with increased PA enjoyment and participation. For boys and girls, team sports/weightlifting was associated with increased participation, and individual activities were indirectly associated with increased participation through enjoyment. For boys, team sports/weightlifting was indirectly related with participation. These findings suggest that participation in a variety of PA is associated with increased PA enjoyment and participation. Providing opportunities for adolescents to engage in a variety of activities might help them identify PA they enjoy and facilitate lifelong PA habits.

  12. Self-assembly of a thin highly reduced graphene oxide film and its high electrocatalytic activity

    Science.gov (United States)

    Bai, Yan-Feng; Zhang, Yong-Fang; Zhou, An-Wei; Li, Hai-Wai; Zhang, Yu; Luong, John H. T.; Cui, Hui-Fang

    2014-10-01

    A thin highly reduced graphene oxide (rGO) film was self-assembled at the dimethyl formamide (DMF)-air interface through evaporation-induced water-assisted thin film formation at the pentane-DMF interface, followed by complete evaporation of pentane. The thin film was transferred onto various solid substrates for film characterization and electrochemical sensing. UV-visible spectrometry, scanning electron microscopy (SEM), atomic force microscopy (AFM) and electrochemistry techniques were used to characterize the film. An rGO film showing 82.8% of the transmittance at 550 nm corresponds to a few layers of rGO nanosheets. The rGO nanosheets cross-stack with each other, lying approximately in the plane of the film. An rGO film collected on a glassy carbon (GC) electrode exhibited improved electrical conductivity compared to GC, with the electrode charge-transfer resistance (Rct) reduced from 31 Ω to 22 Ω. The as-formed rGO/GC electrode was mechanically very stable, exhibiting significantly enhanced electrocatalytic activity to H2O2 and dopamine. Multiple layers of the rGO films on the GC electrode showed even stronger electrocatalytic activity to dopamine than that of the single rGO film layer. The controllable formation of a stable rGO film on various solid substrates has potential applications for nanoelectronics and sensors/biosensors.

  13. Identification of Tumor Endothelial Cells with High Aldehyde Dehydrogenase Activity and a Highly Angiogenic Phenotype

    Science.gov (United States)

    Maishi, Nako; Ohga, Noritaka; Hida, Yasuhiro; Kawamoto, Taisuke; Iida, Junichiro; Shindoh, Masanobu; Tsuchiya, Kunihiko; Shinohara, Nobuo; Hida, Kyoko

    2014-01-01

    Tumor blood vessels play an important role in tumor progression and metastasis. It has been reported that tumor endothelial cells (TECs) exhibit highly angiogenic phenotypes compared with those of normal endothelial cells (NECs). TECs show higher proliferative and migratory abilities than those NECs, together with upregulation of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2). Furthermore, compared with NECs, stem cell markers such as Sca-1, CD90, and multidrug resistance 1 are upregulated in TECs, suggesting that stem-like cells exist in tumor blood vessels. In this study, to reveal the biological role of stem-like TECs, we analyzed expression of the stem cell marker aldehyde dehydrogenase (ALDH) in TECs and characterized ALDHhigh TECs. TECs and NECs were isolated from melanoma-xenografted nude mice and normal dermis, respectively. ALDH mRNA expression and activity were higher in TECs than those in NECs. Next, ALDHhigh/low TECs were isolated by fluorescence-activated cell sorting to compare their characteristics. Compared with ALDHlow TECs, ALDHhigh TECs formed more tubes on Matrigel-coated plates and sustained the tubular networks longer. Furthermore, VEGFR2 expression was higher in ALDHhigh TECs than that in ALDHlow TECs. In addition, ALDH was expressed in the tumor blood vessels of in vivo mouse models of melanoma and oral carcinoma, but not in normal blood vessels. These findings indicate that ALDHhigh TECs exhibit an angiogenic phenotype. Stem-like TECs may have an essential role in tumor angiogenesis. PMID:25437864

  14. Identification of tumor endothelial cells with high aldehyde dehydrogenase activity and a highly angiogenic phenotype.

    Directory of Open Access Journals (Sweden)

    Hitomi Ohmura-Kakutani

    Full Text Available Tumor blood vessels play an important role in tumor progression and metastasis. It has been reported that tumor endothelial cells (TECs exhibit highly angiogenic phenotypes compared with those of normal endothelial cells (NECs. TECs show higher proliferative and migratory abilities than those NECs, together with upregulation of vascular endothelial growth factor (VEGF and VEGF receptor 2 (VEGFR2. Furthermore, compared with NECs, stem cell markers such as Sca-1, CD90, and multidrug resistance 1 are upregulated in TECs, suggesting that stem-like cells exist in tumor blood vessels. In this study, to reveal the biological role of stem-like TECs, we analyzed expression of the stem cell marker aldehyde dehydrogenase (ALDH in TECs and characterized ALDHhigh TECs. TECs and NECs were isolated from melanoma-xenografted nude mice and normal dermis, respectively. ALDH mRNA expression and activity were higher in TECs than those in NECs. Next, ALDHhigh/low TECs were isolated by fluorescence-activated cell sorting to compare their characteristics. Compared with ALDHlow TECs, ALDHhigh TECs formed more tubes on Matrigel-coated plates and sustained the tubular networks longer. Furthermore, VEGFR2 expression was higher in ALDHhigh TECs than that in ALDHlow TECs. In addition, ALDH was expressed in the tumor blood vessels of in vivo mouse models of melanoma and oral carcinoma, but not in normal blood vessels. These findings indicate that ALDHhigh TECs exhibit an angiogenic phenotype. Stem-like TECs may have an essential role in tumor angiogenesis.

  15. JOSHUA: Symmetric Active/Active Replication for Highly Available HPC Job and Resource Management

    Energy Technology Data Exchange (ETDEWEB)

    Uhlemann, Kai [ORNL; Engelmann, Christian [ORNL; Scott, Steven L [ORNL

    2006-01-01

    Most of today's HPC systems employ a single head node for control, which represents a single point of failure as it interrupts an entire HPC system upon failure. Furthermore, it is also a single point of control as it disables an entire HPC system until repair. One of the most important HPC system service running on the head node is the job and resource management. If it goes down, all currently running jobs loose the service they report back to. They have to be restarted once the head node is up and running again. With this paper, we present a generic approach for providing symmetric active/active replication for highly available HPC job and resource management. The JOSHUA solution provides a virtually synchronous environment for continuous availability without any interruption of service and without any loss of state. Replication is performed externally via the PBS service interface without the need to modify any service code. Test results as well as a reliability analysis of our proof-of-concept prototype implementation show that continuous availability can be provided by JOSHUA with an acceptable performance trade-off.

  16. Novel Logarithmic Active Pixel Sensor with High Dynamic Range and High Output Swing

    Institute of Scientific and Technical Information of China (English)

    FU Xian-song; YAO Su-ying; YUAN Yi-dong; XU Jiang-tao; DING Ke; YAN Kun-shan

    2008-01-01

    The logarithmic response complementary metal oxide semiconductor(CMOS) image sensor provides a wide dynamic range, but its drawback is the lack of simple fixed pattern noise(FPN) cancellation scheme. Designed is a novel logarithmic active pixel sensor(APS) with high dynamic range and high output swing. Firstly, the operation principle of mixed-model APS is introduced. The pixel can work in three operation modes by choosing the proper control signals. Then, FPN sources of logarithmic APS are analyzed, and double-sampled technique is implemented to reduce FPN. Finally, according to the simulation results, layout is designed and has passed design rule check(DRC), electronic rule check(ERC) and layout versus schematic(LVS) verifications, and the post-simulation results are basically in agreement with the simulation results. Dynamic range of the new logarithmic APS can reach about 140 dB; and the output swing is about 750 mV. Results show that by using double sampled technique, most FPN is eliminated and the dynamic range is enhanced.

  17. Prometaphase arrest-dependent phosphorylation of Bcl-2 and Bim reduces the association of Bcl-2 with Bak or Bim, provoking Bak activation and mitochondrial apoptosis in nocodazole-treated Jurkat T cells.

    Science.gov (United States)

    Han, Cho Rong; Jun, Do Youn; Lee, Ji Young; Kim, Young Ho

    2014-01-01

    Treatment of Jurkat T cells with the microtubule-depolymerizing agent nocodazole (NOC) caused prometaphase arrest and apoptosis. NOC-induced mitochondrial apoptotic events including Bak activation, Δψm loss, cytochrome c release, and caspase cascade activation were blocked by Bcl-2 overexpression. However, mitotic arrest, Cdc25C activation, upregulation of cyclin B1 levels, Cdk1 activation, Bcl-2 phosphorylation at Thr-56 and Ser-70, and Bim phosphorylation were retained. The treatment of Jurkat T cells concomitantly with NOC and the G1/S-blocking agent hydroxyurea resulted in G1/S arrest and complete abrogation of all apoptotic events. The association of Bcl-2 with Bim or Bak declined after the prometaphase arrest-dependent phosphorylation of Bcl-2 and Bim, whereas the association of Bcl-2 with Bax remained relatively constant. Although Bax was redistributed from the cytosol to the mitochondria, resulting in an increase in the mitochondrial level of Bax following NOC treatment, the subcellular localization of Bcl-2, Bim, Bak and apoptosis-inducing factor was confined to the mitochondrial fraction irrespective of NOC treatment. Experiments using selective caspase inhibitors showed that mitochondria-dependent activation of caspase-9 and -3 was crucial for NOC-induced apoptosis. NOC-induced phosphorylation of Bcl-2 and Bim, Δψm loss, and mitochondria-dependent apoptotic events were significantly suppressed by a Cdk1 inhibitor roscovitine, but not by the JNK inhibitor SP600125 or the p38 MAPK inhibitor SB203580. These results show that the prometaphase arrest-dependent phosphorylation of Bcl-2 and Bim, which was mediated by Cdk1, could reduce the association of Bcl-2 with Bak or Bim to allow Bak activation and mitochondrial apoptotic events in Jurkat T cells exposed to NOC.

  18. Recovery of inspiratory intercostal muscle activity following high cervical hemisection.

    Science.gov (United States)

    Dougherty, B J; Lee, K Z; Gonzalez-Rothi, E J; Lane, M A; Reier, P J; Fuller, D D

    2012-09-30

    Anatomical and neurophysiological evidence indicates that thoracic interneurons can serve a commissural function and activate contralateral motoneurons. Accordingly, we hypothesized that respiratory-related intercostal (IC) muscle electromyogram (EMG) activity would be only modestly impaired by a unilateral cervical spinal cord injury. Inspiratory tidal volume (VT) was recorded using pneumotachography and EMG activity was recorded bilaterally from the 1st to 2nd intercostal space in anesthetized, spontaneously breathing rats. Studies were conducted at 1-3 days, 2 wks or 8 wks following C2 spinal cord hemisection (C2HS). Data were collected during baseline breathing and a brief respiratory challenge (7% CO(2)). A substantial reduction in inspiratory intercostal EMG bursting ipsilateral to the lesion was observed at 1-3 days post-C2HS. However, a time-dependent return of activity occurred such that by 2 wks post-injury inspiratory intercostal EMG bursts ipsilateral to the lesion were similar to age-matched, uninjured controls. The increases in ipsilateral intercostal EMG activity occurred in parallel with increases in VT following the injury (R=0.55; Pintercostal" circuitry enables a robust, spontaneous recovery of ipsilateral intercostal activity following C2HS in rats. Copyright © 2012. Published by Elsevier B.V.

  19. Professional Identities of Vocational High School Students and Extracurricular Activities

    Science.gov (United States)

    Altan, Bilge Aslan; Altintas, Havva Ozge

    2017-01-01

    Vocational high schools are one of the controversial topics, and also the hardly touched fields in educational field. Students' profiles of vocational schools, their visions, and professional identity developments are not frequently reflected in the literature. Therefore, the main aim of the study is to research whether vocational high school…

  20. Application of activated charcoal radon collectors in high humidity environments

    Energy Technology Data Exchange (ETDEWEB)

    Iimoto, Takeshi E-mail: iimoto@rcnst.u-tokyo.ac.jp; Tokonami, Shinji; Morishita, Yasuaki; Kosako, Toshiso

    2004-09-01

    Most commercially based activated charcoal radon collectors were designed for use in indoor environments. However, at present, they are often used for research in radon surveys in unique environments, such as in the bathrooms, underground areas, mines, caves and tunnels. In these environments, the relative humidity would be around 100%, and a change in the sensitivity of cpm(Bq m{sup -3}){sup -1}(radon) would occur. For this study, the reduction in the sensitivity of activated charcoal radon collector due to environmental humidity was investigated, and the data correction was discussed. Here, ST-100 (Pico-Rad) was selected as an example of a familiar activated charcoal radon collector. According to our performance test, the humidity of 90% (20 deg. C) resulted in a 15% reduction of the sensitivity for 24 h collection. The ST-100 user should discuss the necessity of data correction by comparing the change of sensitivity with other levels of estimation errors.

  1. Application of activated charcoal radon collectors in high humidity environments.

    Science.gov (United States)

    Iimoto, Takeshi; Tokonami, Shinji; Morishita, Yasuaki; Kosako, Toshiso

    2005-01-01

    Most commercially based activated charcoal radon collectors were designed for use in indoor environments. However, at present, they are often used for research in radon surveys in unique environments, such as in the bathrooms, underground areas, mines, caves and tunnels. In these environments, the relative humidity would be around 100%, and a change in the sensitivity of cpm(Bq m(-3))(-1)(radon) would occur. For this study, the reduction in the sensitivity of activated charcoal radon collector due to environmental humidity was investigated, and the data correction was discussed. Here, ST-100 (Pico-Rad) was selected as an example of a familiar activated charcoal radon collector. According to our performance test, the humidity of 90% (20 degrees C) resulted in a 15% reduction of the sensitivity for 24 h collection. The ST-100 user should discuss the necessity of data correction by comparing the change of sensitivity with other levels of estimation errors.

  2. Application of Mathematical Modeling Activities in Costarican High School Education

    Directory of Open Access Journals (Sweden)

    Karen Porras-Lizano

    2015-01-01

    Full Text Available This paper describes the experience gained in implementing mathematical modeling activities as a methodological strategy in teaching issues such as proportions, with a group of eighth year of an academic-day-school, located in the province of San Jose, Costa Rica in 2012. Different techniques for gathering information were applied, such as participant observation and questionnaires. Among the relevant results are the cyclical development of mathematical thinking of students in the stages of mathematical modeling (description, manipulation, prediction and validation for solving the problem; developing of teamwork skills; and appreciation of mathematics as a useful and effective discipline. To resolve the activities proposed in this study, social interactions such as sharing information, thoughts and ideas, were generated, stimulating the zone of proximal development of the participating students. Likewise, the mathematical modeling activities allowed students to have a positive role in mathematics classes, stimulating, in turn, a different attitude compared to regular classes.

  3. Raman active high energy excitations in URu2Si2

    Science.gov (United States)

    Buhot, Jonathan; Gallais, Yann; Cazayous, Maximilien; Sacuto, Alain; Piekarz, Przemysław; Lapertot, Gérard; Aoki, Dai; Méasson, Marie-Aude

    2017-02-01

    We have performed Raman scattering measurements on URu2Si2 single crystals on a large energy range up to ∼1300 cm-1 and in all the Raman active symmetries as a function of temperature down to 15 K. A large excitation, active only in the Eg symmetry, is reported. It has been assigned to a crystal electric field excitation on the Uranium site. We discuss how this constrains the crystal electric field scheme of the Uranium ions. Furthermore, three excitations in the A1g symmetry are observed. They have been associated to double Raman phonon processes consistently with ab initio calculations of the phonons dispersion.

  4. High Resolution Processing with an Active Phased Array SAR

    NARCIS (Netherlands)

    Nijenboer, F.J.; Otten, M.P.G.

    1999-01-01

    The Dutch PHARUS system is a polarimetric active phased array SAR capable of performing advanced SAR modes. Advanced SAR modes that are being investigated are: spotlight SAR, sliding spotlight SAR, stepped frequency SAR and interferometric SAR. The flight experiments and automatic beam steering

  5. Active Snubber Circuit for High Power Inverter Leg

    DEFF Research Database (Denmark)

    Rasmussen, Tonny Wederberg; Johansen, Morten Holst

    2009-01-01

    circuits have been introduced to reduce the loss even though some of the loss is removed from the IGBT to the snubber resistance. This paper takes also the next step to introduce the active Undeland snubber which in principle is lossless. The paper describes this solution together with some simulations...

  6. Active Snubber Circuit for High Power Inverter Leg

    DEFF Research Database (Denmark)

    Rasmussen, Tonny Wederberg; Johansen, Morten Holst

    2009-01-01

    circuits have been introduced to reduce the loss even though some of the loss is removed from the IGBT to the snubber resistance. This paper takes also the next step to introduce the active Undeland snubber which in principle is lossless. The paper describes this solution together with some simulations...

  7. Easy and Rapid Purification of Highly Active Nisin

    NARCIS (Netherlands)

    Abts, André; Mavaro, Antonino; Stindt, Jan; Bakkes, Patrick J.; Metzger, Sabine; Driessen, Arnold J.M.; Smits, Sander H.J.; Schmitt, Lutz

    2011-01-01

    Nisin is an antimicrobial peptide produced and secreted by several L. lactis strains and is specifically active against Gram-positive bacteria. In previous studies, nisin was purified via cation exchange chromatography at low pH employing a single-step elution using 1M NaCl. Here, we describe an opt

  8. Physical activity in physiotherapy and physical education high school students

    Directory of Open Access Journals (Sweden)

    Mihailova A.

    2014-01-01

    Full Text Available A term of health-related physical fitness became topical with four its components: aerobic and/or cardiovascular fitness, body composition, abdominal muscle strength and endurance, and lower back and hamstring flexibility. Complex evaluation of health-related physical fitness and physical activity (PA may show a wider insight in health promotion and disease prevention. The aim of this study was to evaluate physical activity relation to health-related physical fitness in Physiotherapy (PT and Physical Education (PE students. Final study sample consisted of 67 students (46 women and 21 men (aged 21.61 ± 0.71. All participants filled in International Physical Activity Questionnaire. Health-related physical testing included: 1 body composition evaluation, 2 abdominal muscles strength tests, 3 dynamometry, 4 hamstring muscles and m. quadratus lumborum elasticity evaluation tests, 5 bicycle ergometer test (anaerobic threshold, maximal oxygen consumption. Results showed that most students had normal body composition parameters (BMI, body fat, muscle mass, body water in both genders and study programs. Women were less physically active that men, and PA duration was higher in PE students. PT students had higher body composition values, lower cardiorespiratory fitness parameters and lower handgrip strength in both hands than PE students. Greater PA generally implies a higher level of health-related physical fitness. PA significantly positively affects body composition, upper m. rectus abdominisstrength, grip strength and aerobic capacity.

  9. Easy and Rapid Purification of Highly Active Nisin

    NARCIS (Netherlands)

    Abts, André; Mavaro, Antonino; Stindt, Jan; Bakkes, Patrick J.; Metzger, Sabine; Driessen, Arnold J.M.; Smits, Sander H.J.; Schmitt, Lutz

    2011-01-01

    Nisin is an antimicrobial peptide produced and secreted by several L. lactis strains and is specifically active against Gram-positive bacteria. In previous studies, nisin was purified via cation exchange chromatography at low pH employing a single-step elution using 1M NaCl. Here, we describe an

  10. Novel, high-activity hydroprocessing catalysts: Iron group phosphides

    Science.gov (United States)

    Wang, Xianqin

    A series of iron, cobalt and nickel transition metal phosphides was synthesized by means of temperature-programmed reduction (TPR) of the corresponding phosphates. The same materials, Fe2P, CoP and NO, were also prepared on a silica (SiO2) support. The phase purity of these catalysts was established by x-ray diffraction (XRD), and the surface properties were determined by N2 BET specific surface area (Sg) measurements and CO chemisorption. The activities of the silica-supported catalysts were tested in a three-phase trickle bed reactor for the simultaneous hydrodenitrogenation (HDN) of quinoline and hydrodesulfurization (HDS) of dibenzothiophene using a model liquid feed at realistic conditions (30 atm, 370°C). The reactivity studies showed that the nickel phosphide (Ni2P/SiO2) was the most active of the catalysts. Compared with a commercial Ni-Mo-S/gamma-Al 2O3 catalyst at the same conditions, Ni2P/silica had a substantially higher HDS activity (100% vs. 76%) and HDN activity (82% vs. 38%). Because of their good hydrotreating activity, an extensive study of the preparation of silica supported nickel phosphides, Ni2P/SiO 2, was carried out. The parameters investigated were the phosphorus content and the weight loading of the active phase. The most active composition was found to have a starting synthesis Ni/P ratio close to 1/2, and the best loading of this sample on silica was observed to be 18 wt.%. Extended x-ray absorption fine structure (EXAFS) and x-ray absorption near edge spectroscopy (XANES) measurements were employed to determine the structures of the supported samples. The main phase before and after reaction was found to be Ni2P, but some sulfur was found to be retained after reaction. A comprehensive scrutiny of the HDN reaction mechanism was also made over the Ni2P/SiO2 sample (Ni/P = 1/2) by comparing the HDN activity of a series of piperidine derivatives of different structure. It was found that piperidine adsorption involved an alpha-H activation

  11. Synthesis of a high specific activity methyl sulfone tritium isotopologue of fevipiprant (NVP-QAW039).

    Science.gov (United States)

    Luu, Van T; Goujon, Jean-Yves; Meisterhans, Christian; Frommherz, Matthias; Bauer, Carsten

    2015-05-15

    The synthesis of a triple tritiated isotopologue of the CRTh2 antagonist NVP-QAW039 (fevipiprant) with a specific activity >3 TBq/mmol is described. Key to the high specific activity is the methylation of a bench-stable dimeric disulfide precursor that is in situ reduced to the corresponding thiol monomer and methylated with [(3)H3]MeONos having per se a high specific activity. The high specific activity of the tritiated active pharmaceutical ingredient obtained by a build-up approach is discussed in the light of the specific activity usually to be expected if hydrogen tritium exchange methods were applied.

  12. Development and Application of Plasma Actuators for Active Control of High-Speed and High Reynolds Number Flows

    Science.gov (United States)

    Sammy, Mo

    2010-01-01

    Active flow control is often used to manipulate flow instabilities to achieve a desired goal (e.g. prevent separation, enhance mixing, reduce noise, etc.). Instability frequencies normally scale with flow velocity scale and inversely with flow length scale (U/l). In a laboratory setting for such flow experiments, U is high, but l is low, resulting in high instability frequency. In addition, high momentum and high background noise & turbulence in the flow necessitate high amplitude actuation. Developing a high amplitude and high frequency actuator is a major challenge. Ironically, these requirements ease up in application (but other issues arise).

  13. Shyness, Physical Activity, and Sports Team Participation among Philippine High School Students.

    Science.gov (United States)

    Page, Randy M.; Zarco, Emilia Patricia

    2001-01-01

    Examined relationship between shyness and physical activity among Philippine high schoolers. Found that Philippine students reported less physical activity than U.S. students on the Youth Risk Behavior Survey. Highly shy Filipino students participated in vigorous physical activity significantly less often than those with average or low shyness and…

  14. Trabectedin has promising antineoplastic activity in high-grade meningioma.

    Science.gov (United States)

    Preusser, Matthias; Spiegl-Kreinecker, Sabine; Lötsch, Daniela; Wöhrer, Adelheid; Schmook, Maria; Dieckmann, Karin; Saringer, Walter; Marosi, Christine; Berger, Walter

    2012-10-15

    Meningiomas are common intracranial tumors arising from the meninges and usually are benign. However, a few meningiomas have aggressive behavior and, for such patients, effective treatment options are needed. Trabectedin is a novel, marine-derived, antineoplastic agent that has been approved and is used routinely as therapy for advanced soft tissue sarcoma and ovarian cancer. The authors investigated the in vitro effects of trabectedin alone and in combination with hydroxyurea, cisplatin, and doxorubicin in primary cell cultures of benign (n = 9), atypical (n = 6), and anaplastic (n = 4) meningiomas using chemosensitivity assays (3-[4,5dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide [MTT]), Western blot analysis, cell cycle analysis, and immunofluorescent staining. Strong antimeningioma activity of trabectedin was observed and was characterized by distinct cell cycle arrest, down-regulation of multiple cyclins, deregulated expression of cell death-regulatory genes, and massive apoptosis induction. Cytotoxic activity was especially intense in higher grade meningiomas with a half-maximal inhibitory concentration <10 nM. Combination with trabectedin synergistically enhanced the antimeningioma activity of hydroxyurea but also enhanced the activity of doxorubicin and cisplatin. On the basis of these findings, trabectedin was given to 1 patient who had heavily pretreated, anaplastic meningioma, and a favorable response was observed with radiologic disease stabilization, marked reductions in brain edema and requirement for corticosteroids, and improvement of clinical symptoms. However, treatment had to be discontinued after 5 cycles because of adverse drug effects. The current results indicated that trabectedin may represent a promising new therapeutic option for patients with aggressive meningioma and should be evaluated in prospective clinical studies. Copyright © 2012 American Cancer Society.

  15. A High-Speed Active Switch Routing Architecture

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, combining with active networks, we design a new kind of programmable routing switch architecture to provide a common intelligent switch platform for multi-protocol switching and multi-service accessing. We elaborate how programmable switch and network intelligence are achieved, and how packets are classified, queued and scheduled. We point out that edge intelligence and network software are the tendency for the development of future networks.

  16. Unique Gold Nanoparticle Aggregates as a Highly Active SERS Substrate

    Energy Technology Data Exchange (ETDEWEB)

    Schwartzberg, A M; Grant, C D; Wolcott, A; Talley, C E; Huser, T R; Bogomolni, R; Zhang, J Z

    2004-04-06

    A unique gold nanoparticle aggregate (GNA) system has been shown to be an excellent substrate for surface-enhanced Raman scattering (SERS) applications. Rhodamine 6G (R6G), a common molecule used for testing SERS activity on silver, but generally difficult to detect on gold substrates, has been found to readily bind to the GNA and exhibit strong SERS activity due to the unique surface chemistry afforded by sulfur species on the surface. This GNA system has yielded a large SERS enhancement of 10{sup 7}-10{sup 9} in bulk solution for R6G, on par with or greater than any previously reported gold SERS substrate. SERS activity has also been successfully demonstrated for several biological molecules including adenine, L-cysteine, L-lysine, and L-histidine for the first time on a gold SERS substrate, showing the potential of this GNA as a convenient and powerful SERS substrate for biomolecular detection. In addition, SERS spectrum of R6G on single aggregates has been measured. We have shown that the special surface properties of the GNA, in conjunction with strong near IR absorption, make it useful for SERS analysis of a wide variety of molecules.

  17. Selective disruption of high sensitivity heat activation but not capsaicin activation of TRPV1 channels by pore turret mutations.

    Science.gov (United States)

    Cui, Yuanyuan; Yang, Fan; Cao, Xu; Yarov-Yarovoy, Vladimir; Wang, KeWei; Zheng, Jie

    2012-04-01

    The capsaicin receptor transient receptor potential vanilloid (TRPV)1 is a highly heat-sensitive ion channel. Although chemical activation and heat activation of TRPV1 elicit similar pungent, painful sensation, the molecular mechanism underlying synergistic activation remains mysterious. In particular, where the temperature sensor is located and whether heat and capsaicin share a common activation pathway are debated. To address these fundamental issues, we searched for channel mutations that selectively affected one form of activation. We found that deletion of the first 10 amino acids of the pore turret significantly reduced the heat response amplitude and shifted the heat activation threshold, whereas capsaicin activation remained unchanged. Removing larger portions of the turret disrupted channel function. Introducing an artificial sequence to replace the deleted region restored sensitive capsaicin activation in these nonfunctional channels. The heat activation, however, remained significantly impaired, with the current exhibiting diminishing heat sensitivity to a level indistinguishable from that of a voltage-gated potassium channel, Kv7.4. Our results demonstrate that heat and capsaicin activation of TRPV1 are structurally and mechanistically distinct processes, and the pore turret is an indispensible channel structure involved in the heat activation process but is not part of the capsaicin activation pathway. Synergistic effect of heat and capsaicin on TRPV1 activation may originate from convergence of the two pathways on a common activation gate.

  18. Application of the IEAF-2001 activation data library to activation analyses of the IFMIF high flux test module

    CERN Document Server

    Fischer, U; Leichtle, D; Simakov, S P; Moellendorff, U V; Konobeev, A; Korovin, Y; Pereslavtsev, P; Schmuck, I

    2002-01-01

    A complete activation data library IEAF-2001 (intermediate energy activation file) has been developed in standard ENDF-6 format with neutron-induced activation cross sections for 679 target nuclides from Z=1 (hydrogen) to Z=84 (polonium) and incident neutron energies up to 150 MeV. Using the NJOY processing code, an IEAF-2001 working library has been prepared in a 256 energy group structure for enabling activation analyses of the International Fusion Material Irradiation Facility (IFMIF) D-Li neutron source. This library was applied to the activation analysis of the IFMIF high flux test module using the recent Analytical and Laplacian Adaptive Radioactivity Analysis activation code which is capable of handling the variety of reaction channels open in the energy domain above 20 MeV. The IEAF-2001 activation library was thus shown to be suitable for activation analyses in fusion technology and intermediate energy applications such as the IFMIF D-Li neutron source.

  19. High energy physics division semiannual report of research activities

    Energy Technology Data Exchange (ETDEWEB)

    Schoessow, P.; Moonier, P.; Talaga, R.; Wagner, R. (eds.) (Argonne National Lab., IL (United States))

    1991-08-01

    This report describes the research conducted in the High Energy Physics Division of Argonne National Laboratory during the period of January 1, 1991--June 30, 1991. Topics covered here include experimental and theoretical particle physics, advanced accelerator physics, detector development, and experimental facilities research. Lists of division publications and colloquia are included.

  20. Student Activism in the High Schools of New York State.

    Science.gov (United States)

    Haake, Bernard F.; Langworthy, Philip B.

    The purpose of nine regional meetings between New York State Education Department personnel, educators and students from selected secondary school districts was to obtain information about unrest and the changing expectations of high school students. The following conclusions were made: (1) rising expectations of students are part of the "times,"…

  1. High-Tc superconducting quantum interference device recordings of spontaneous brain activity: Towards high-Tc magnetoencephalography

    Science.gov (United States)

    Öisjöen, F.; Schneiderman, J. F.; Figueras, G. A.; Chukharkin, M. L.; Kalabukhov, A.; Hedström, A.; Elam, M.; Winkler, D.

    2012-03-01

    We have performed single- and two-channel high transition temperature (high-Tc) superconducting quantum interference device (SQUID) magnetoencephalography (MEG) recordings of spontaneous brain activity in two healthy human subjects. We demonstrate modulation of two well-known brain rhythms: the occipital alpha rhythm and the mu rhythm found in the motor cortex. We further show that despite higher noise-levels compared to their low-Tc counterparts, high-Tc SQUIDs can be used to detect and record physiologically relevant brain rhythms with comparable signal-to-noise ratios. These results indicate the utility of high-Tc technology in MEG recordings of a broader range of brain activity.

  2. Highly sensitive index of sympathetic activity based on time-frequency spectral analysis of electrodermal activity.

    Science.gov (United States)

    Posada-Quintero, Hugo F; Florian, John P; Orjuela-Cañón, Álvaro D; Chon, Ki H

    2016-09-01

    Time-domain indices of electrodermal activity (EDA) have been used as a marker of sympathetic tone. However, they often show high variation between subjects and low consistency, which has precluded their general use as a marker of sympathetic tone. To examine whether power spectral density analysis of EDA can provide more consistent results, we recently performed a variety of sympathetic tone-evoking experiments (43). We found significant increase in the spectral power in the frequency range of 0.045 to 0.25 Hz when sympathetic tone-evoking stimuli were induced. The sympathetic tone assessed by the power spectral density of EDA was found to have lower variation and more sensitivity for certain, but not all, stimuli compared with the time-domain analysis of EDA. We surmise that this lack of sensitivity in certain sympathetic tone-inducing conditions with time-invariant spectral analysis of EDA may lie in its inability to characterize time-varying dynamics of the sympathetic tone. To overcome the disadvantages of time-domain and time-invariant power spectral indices of EDA, we developed a highly sensitive index of sympathetic tone, based on time-frequency analysis of EDA signals. Its efficacy was tested using experiments designed to elicit sympathetic dynamics. Twelve subjects underwent four tests known to elicit sympathetic tone arousal: cold pressor, tilt table, stand test, and the Stroop task. We hypothesize that a more sensitive measure of sympathetic control can be developed using time-varying spectral analysis. Variable frequency complex demodulation, a recently developed technique for time-frequency analysis, was used to obtain spectral amplitudes associated with EDA. We found that the time-varying spectral frequency band 0.08-0.24 Hz was most responsive to stimulation. Spectral power for frequencies higher than 0.24 Hz were determined to be not related to the sympathetic dynamics because they comprised less than 5% of the total power. The mean value of time

  3. Acetylcholine-releasing effect of primycin, a highly active antibiotic.

    Science.gov (United States)

    Adám-Vizi, V; Horváth, I; Vizi, E S

    1980-01-01

    The effect of primycin, an antibiotic known to inhibit potassium conductance, was studied on acetylcholine (ACh) release from the nerve terminals of the Auerbach plexus and cortical slice of the rat. Primycin enhanced the resting release of ACh; however, it failed to affect the amount of ACh released by a single shock. It has no effect on Na+K+-activated ATPase. Its effect on Ach release was prevented by tetrodotoxin and by Ca removal. It is concluded that its effect on potassium conductance might account for its ACh-releasing effect: it produces depolarization and spontaneous firing.

  4. Efficacy of natalizumab in multiple sclerosis patients with high disease activity: a Danish nationwide study

    DEFF Research Database (Denmark)

    Oturai, A.B.; Koch-Henriksen, N.; Petersen, T.;

    2009-01-01

    INTRODUCTION: Previous studies of natalizumab (Tysabri) in relapsing multiple sclerosis (MS) patients have included patients with moderate disease activity. We studied a patient population with high disease activity. PATIENTS AND METHODS: We analyzed data from 234 consecutive, natalizumab-treated...

  5. Design of a high activity and selectivity alcohol catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Foley, H.C.; Mills, G.A.

    1992-11-30

    Efforts to synthesize bimetallic cluster-derived Rh-Mo catalysts for CO and CO[sub 2] hydrogenation to preferentially produce oxygenates. The rhodium-molybdenum cluster, (PPh[sub 3])[sub 2]RhMO(CO)([mu]-CO)[sub 2]Cp, was employed as a precursor to alumina- and silica-supported catalysts which were in CO hydrogenation. When compared to catalysts made from the distinct organometallic complexes, RhH(CO)(PPh[sub 3])[sub 3] and [MO(CO)[sub 3]Cp][sub 2], the catalysts derived from a binuclear precursor show higher activities for CO hydrogenation and superior selectivities towards oxygenates, namely, methanol, dimethyl ether and ethanol. Their product distributions depend on the support. Fourier transform infrared spectroscopy studies indicate that CO chemisorbs on cluster-derived catalysts as gem-dicarbonyls while it is chemisorbed only in the linear-carbonyl configuration on catalysts made from separate rhodium and molybdenum complexes. The particular oxygenate selectivity of the cluster-derived catalysts may be correlated to the strong electronic interaction between Rh and Mo. Carbon dioxide hydrogenation has also been carried out on the catalysts mentioned above. Again, the cluster-derived catalysts show higher oxygenate selectivities. Finally, the catalysts were studied with regard to both CO and CO[sub 2] hydrogenation kinetics, apparent activation energies inferred.

  6. High-throughput design of low-activation, high-strength creep-resistant steels for nuclear-reactor applications

    Science.gov (United States)

    Lu, Qi; van der Zwaag, Sybrand; Xu, Wei

    2016-02-01

    Reduced-activation ferritic/martensitic steels are prime candidate materials for structural applications in nuclear power reactors. However, their creep strength is much lower than that of creep-resistant steel developed for conventional fossil-fired power plants as alloying elements with a high neutron activation cannot be used. To improve the creep strength and to maintain a low activation, a high-throughput computational alloy design model coupling thermodynamics, precipitate-coarsening kinetics and an optimization genetic algorithm, is developed. Twelve relevant alloying elements with either low or high activation are considered simultaneously. The activity levels at 0-10 year after the end of irradiation are taken as optimization parameter. The creep-strength values (after exposure for 10 years at 650 °C) are estimated on the basis of the solid-solution strengthening and the precipitation hardening (taking into account precipitate coarsening). Potential alloy compositions leading to a high austenite fraction or a high percentage of undesirable second phase particles are rejected automatically in the optimization cycle. The newly identified alloys have a much higher precipitation hardening and solid-solution strengthening at the same activity level as existing reduced-activation ferritic/martensitic steels.

  7. High-throughput design of low-activation, high-strength creep-resistant steels for nuclear-reactor applications

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Qi; Zwaag, Sybrand van der [Novel Aerospace Materials Group, Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS, Delft (Netherlands); Xu, Wei, E-mail: xuwei@ral.neu.edu.cn [State Key Laboratory of Rolling and Automation, Northeastern University, 110819, Shenyang (China); Novel Aerospace Materials Group, Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS, Delft (Netherlands)

    2016-02-15

    Reduced-activation ferritic/martensitic steels are prime candidate materials for structural applications in nuclear power reactors. However, their creep strength is much lower than that of creep-resistant steel developed for conventional fossil-fired power plants as alloying elements with a high neutron activation cannot be used. To improve the creep strength and to maintain a low activation, a high-throughput computational alloy design model coupling thermodynamics, precipitate-coarsening kinetics and an optimization genetic algorithm, is developed. Twelve relevant alloying elements with either low or high activation are considered simultaneously. The activity levels at 0–10 year after the end of irradiation are taken as optimization parameter. The creep-strength values (after exposure for 10 years at 650 °C) are estimated on the basis of the solid-solution strengthening and the precipitation hardening (taking into account precipitate coarsening). Potential alloy compositions leading to a high austenite fraction or a high percentage of undesirable second phase particles are rejected automatically in the optimization cycle. The newly identified alloys have a much higher precipitation hardening and solid-solution strengthening at the same activity level as existing reduced-activation ferritic/martensitic steels.

  8. High-Resolution Spectroscopy of some very Active Southern Stars

    Science.gov (United States)

    Soderblom, David R.; King, Jeremy R.; Henry, Todd J.

    1998-01-01

    We have obtained high-resolution echelle spectra of 18 solar-type stars that an earlier survey showed to have very high levels of Ca II H and K emission. Most of these stars belong to close binary systems, but five remain as probable single stars or well-separated binaries that are younger than the Pleiades on the basis of their lithium abundances and H.alpha emission. Three of these probable single stars also lie more than 1 mag above the main sequence in a color-magnitude diagram, and appear to have ages of 10 to 15 Myr. Two of them, HD 202917 and HD 222259, also appear to have a kinematic association with the pre-main-sequence multiple system HD 98800.

  9. High-resolution eye tracking using V1 neuron activity

    Science.gov (United States)

    McFarland, James M.; Bondy, Adrian G.; Cumming, Bruce G.; Butts, Daniel A.

    2014-01-01

    Studies of high-acuity visual cortical processing have been limited by the inability to track eye position with sufficient accuracy to precisely reconstruct the visual stimulus on the retina. As a result, studies on primary visual cortex (V1) have been performed almost entirely on neurons outside the high-resolution central portion of the visual field (the fovea). Here we describe a procedure for inferring eye position using multi-electrode array recordings from V1 coupled with nonlinear stimulus processing models. We show that this method can be used to infer eye position with one arc-minute accuracy – significantly better than conventional techniques. This allows for analysis of foveal stimulus processing, and provides a means to correct for eye-movement induced biases present even outside the fovea. This method could thus reveal critical insights into the role of eye movements in cortical coding, as well as their contribution to measures of cortical variability. PMID:25197783

  10. Soluble urokinase plasminogen activator receptor is a marker of dysmetabolism in HIV-infected patients receiving highly active antiretroviral therapy

    DEFF Research Database (Denmark)

    Andersen, Ove; Eugen-Olsen, Jesper; Kofoed, Kristian;

    2008-01-01

    Circulating soluble urokinase plasminogen activator receptor (suPAR) reflects the immune and pro-inflammatory status of the HIV-infected patient. Highly active antiretroviral therapy (HAART) suppresses suPAR. Independent of the immune response to HAART, suPAR remains elevated in some HIV-infected...

  11. Effect of low temperature on highly unsaturated fatty acid biosynthesis in activated sludge.

    Science.gov (United States)

    He, Su; Ding, Li-Li; Xu, Ke; Geng, Jin-Ju; Ren, Hong-Qiang

    2016-07-01

    Low temperature is a limiting factor for the microbial activity of activated sludge for sewage treatment plant in winter. Highly unsaturated fatty acid (UFA) biosynthesis, phospholipid fatty acid (PLFA) constituents and microbial structure in activated sludge at low temperature were investigated. Over 12 gigabases of metagenomic sequence data were generated with the Illumina HiSeq 2000 platform. The result showed 43.11% of phospholipid fatty acid (PLFA) in the activated sludge participated in UFA biosynthesis, and γ-Linolenic could be converted to Arachidonic acid at low temperature. The highly UFA biosynthesis in activated sludge was n-6 highly UFA biosynthesis, rather than n-3 highly UFA biosynthesis. The microbial community structures of activated sludge were analyzed by PLFA and high-throughput sequencing (HiSeq) simultaneously. Acidovorax, Pseudomonas, Flavobacterium and Polaromonas occupied higher percentage at 5°C, and genetic changes of highly UFA biosynthesis derived from microbial community structures change.

  12. High Accuracy Human Activity Monitoring using Neural network

    CERN Document Server

    Sharma, Annapurna; Chung, Wan-Young

    2011-01-01

    This paper presents the designing of a neural network for the classification of Human activity. A Triaxial accelerometer sensor, housed in a chest worn sensor unit, has been used for capturing the acceleration of the movements associated. All the three axis acceleration data were collected at a base station PC via a CC2420 2.4GHz ISM band radio (zigbee wireless compliant), processed and classified using MATLAB. A neural network approach for classification was used with an eye on theoretical and empirical facts. The work shows a detailed description of the designing steps for the classification of human body acceleration data. A 4-layer back propagation neural network, with Levenberg-marquardt algorithm for training, showed best performance among the other neural network training algorithms.

  13. Centrifugally activated bearing for high-speed rotating machinery

    Science.gov (United States)

    Post, Richard F.

    1994-01-01

    A centrifugally activated bearing is disclosed. The bearing includes an annular member that extends laterally and radially from a central axis. A rotating member that rotates about the central axis relative to the annular member is also included. The rotating member has an interior chamber that surrounds the central axis and in which the annular member is suspended. Furthermore, the interior chamber has a concave shape for retaining a lubricant therein while the rotating member is at rest and for retaining a lubricant therein while the rotating member is rotating. The concave shape is such that while the rotating member is rotating a centrifugal force causes a lubricant to be forced away from the central axis to form a cylindrical surface having an axis collinear with the central axis. This centrifugally displaced lubricant provides restoring forces to counteract lateral displacement during operation.

  14. High antimicrobial activity of VLC isolated fractions from Bifurcaria bifurcata

    Directory of Open Access Journals (Sweden)

    Andre Horta

    2014-06-01

    Full Text Available Infectious diseases continue to be a major public health problem and consequently there is perpetual need for new drugs. In this current study, the antimicrobial potential of isolated fractions from Bifurcaria bifurcata collected in Peniche coast was evaluated. Nine fractions of Bifurcaria bifurcata dichloromethane extracts were produced by Vacuum Liquid Chromatography (VLC using cyclohexane with increasing amounts of 10% of ethyl acetate. All of the VLC fractions were tested against four microorganisms, namely Escherichia coli (ATCC 25922, Staphylococcus aureus (ATCC 12600, Candida albicans (ATCC 10231 and Bacillus subtilis (ATCC 6633. Ampicillin, Chloramphenicol and Amphotericin B was used as positive control. In antimicrobial assays, the F4 fraction showed the best result with IC50 38.28 µg/ml (20.18-72.60 against B. subtilis growth. In same microorganism, the fractions F2 (IC50:183.1 µg/ml (110.5-305.6, F3 (IC50: 71.56 µg/ml (48.10-106.4 and F5 ((IC50: 95.23 µg/ml (60.02-151.1 also inhibited the B. subtilis growth. The fractions F3 (IC50: 184.3 µg/ml (94.82-358.1, F4 (IC50: 113.5 µg/ml (67.76-190.0 and F5 (IC50: 439.6 µg/ml (249.4-774.8 exhibited the highest activity against S. aureus. The fractions F3 and F4 inhibited the C. albicans growth with IC50 of 285.2 µg/ml (146.1-557.1 and 133.6 µg/ml (66.73-267.5, respectively. By contrast, all fractions need more than 1mg/ml to inhibit 50% of E. coli growth. In conclusion, the Bifurcaria bifurcata fractions, collected in Peniche, can be used as source of molecules with a great antimicrobial activity.

  15. Performance of alkaline activated slag at high temperatures

    Directory of Open Access Journals (Sweden)

    Mejía de Gutiérrez, R.

    2004-12-01

    Full Text Available This paper presents an investigation into the performance of alkali-activated slag (AAS mortar exposed to elevated temperatures. Sodium silicate, sodium hydroxide and a mix (waterglass with a modulus (SiO2/Na20 of 1.5 were used as activators. The specimens were heated in an electric furnace up to 1000 ºC in steps of 200 ºC for a constant period of 2 hours. The weight loss, residual compressive strength, resistance to chloride ion penetration, porosity and capillary sorption were evaluated and the results were compared with those of ordinary and blended Portland cement mortar

    En el presente traba jo se estudió el comportamiento frente a ¡a temperatura de morteros producidos a partir de escorias siderúrgicas activadas alcalinamente (EAA, utilizando diferentes activantes tales como silicato sódico, hidróxido de sodio y sus correspondientes mezclas. Cada espécimen se expuso por dos horas a temperaturas hasta de 1.000 ºC, en intervalos de 200 °C y en cada caso se determinaron los cambios de color peso, resistencia mecánica y durabilidad. Esta última propiedad se evaluó determinando las modificaciones de porosidad y permeabilidad a cloruros. Los resultados se comparan con los obtenidos en morteros de cemento Portland con y sin adición, específicamente con aquéllos que incorporan humo de sílice.

  16. Innovative activity of high-technology companies as assessment and forecasting object

    Directory of Open Access Journals (Sweden)

    A. E. Sklyarov

    2016-01-01

    Full Text Available Innovation activities, as well as innovations, are closely related meanings, and like many others economical definitions, have a broad range of meanings. Main characteristics and attributes of innovation involves new or significantly improved product, that’s being used, or in other words, found its application, and innovative activitiesactivities focused on realization of innovations. In this article, innovations are mainly considered in terms of high-technology production, evidence from Russian space industry. There are 5 basic stages of lifecycle of innovative project in considered industry: initiation, development, realization, expansion, consumption. Practically, third or fourth, or even both of these stages, often missing because there is no need of them. R&D activities, or even further serial production, based on previous developments, is an innovation activity, because these activities are stages of innovative projects lifecycle itself. Then it seems legit, to draw a conclusion, that in terms of high-technology production, company’s primary activity equals innovative activity. Basic characteristics of innovative activity of high-technology companies as assessment and forecasting object involves high level of uncertainty at every stage of projects lifecycle, high dependency on funding level of this activity, and high level and erratic structure of risk. All the above mentioned, means that assessment and forecasting of innovative activity of high-technology companies, needs development of its own methodological tools for each industry.

  17. High temperature sensor/microphone development for active noise control

    Science.gov (United States)

    Shrout, Thomas R.

    1993-01-01

    The industrial and scientific communities have shown genuine interest in electronic systems which can operate at high temperatures, among which are sensors to monitor noise, vibration, and acoustic emissions. Acoustic sensing can be accomplished by a wide variety of commercially available devices, including: simple piezoelectric sensors, accelerometers, strain gauges, proximity sensors, and fiber optics. Of the several sensing mechanisms investigated, piezoelectrics were found to be the most prevalent, because of their simplicity of design and application and, because of their high sensitivity over broad ranges of frequencies and temperature. Numerous piezoelectric materials are used in acoustic sensors today; but maximum use temperatures are imposed by their transition temperatures (T(sub c)) and by their resistivity. Lithium niobate, in single crystal form, has the highest operating temperature of any commercially available material, 650 C; but that is not high enough for future requirements. Only two piezoelectric materials show potential for use at 1000 C; AlN thin film reported to be piezoactive at 1150 C, and perovskite layer structure (PLS) materials, which possess among the highest T(sub c) (greater than 1500 C) reported for ferroelectrics. A ceramic PLS composition was chosen. The solid solution composition, 80% strontium niobate (SN) and 20% strontium tantalate (STa), with a T(sub c) approximately 1160 C, was hot forged, a process which concurrently sinters and renders the plate-like grains into a highly oriented configuration to enhance piezo properties. Poled samples of this composition showed coupling (k33) approximately 6 and piezoelectric strain constant (d33) approximately 3. Piezoactivity was seen at 1125 C, the highest temperature measurement reported for a ferroelectric ceramic. The high temperature piezoelectric responses of this, and similar PLS materials, opens the possibility of their use in electronic devices operating at temperatures up to

  18. High-frequency underwater plasma discharge application in antibacterial activity

    Science.gov (United States)

    Ahmed, M. W.; Choi, S.; Lyakhov, K.; Shaislamov, U.; Mongre, R. K.; Jeong, D. K.; Suresh, R.; Lee, H. J.

    2017-03-01

    Plasma discharge is a novel disinfection and effectual inactivation approach to treat microorganisms in aqueous systems. Inactivation of Gram-negative Escherichia coli ( E. coli) by generating high-frequency, high-voltage, oxygen (O2) injected and hydrogen peroxide (H2O2) added discharge in water was achieved. The effect of H2O2 dose and oxygen injection rate on electrical characteristics of discharge and E. coli disinfection has been reported. Microbial log reduction dependent on H2O2 addition with O2 injection was observed. The time variation of the inactivation efficiency quantified by the log reduction of the initial E. coli population on the basis of optical density measurement was reported. The analysis of emission spectrum recorded after discharge occurrence illustrated the formation of oxidant species (OH•, H, and O). Interestingly, the results demonstrated that O2 injected and H2O2 added, underwater plasma discharge had fabulous impact on the E. coli sterilization. The oxygen injection notably reduced the voltage needed for generating breakdown in flowing water and escalated the power of discharge pulses. No impact of hydrogen peroxide addition on breakdown voltage was observed. A significant role of oxidant species in bacterial inactivation also has been identified. Furthermore the E. coli survivability in plasma treated water with oxygen injection and hydrogen peroxide addition drastically reduced to zero. The time course study also showed that the retardant effect on E. coli colony multiplication in plasma treated water was favorable, observed after long time. High-frequency underwater plasma discharge based biological applications is technically relevant and would act as baseline data for the development of novel antibacterial processing strategies.

  19. High-frequency underwater plasma discharge application in antibacterial activity

    Science.gov (United States)

    Ahmed, M. W.; Choi, S.; Lyakhov, K.; Shaislamov, U.; Mongre, R. K.; Jeong, D. K.; Suresh, R.; Lee, H. J.

    2017-03-01

    Plasma discharge is a novel disinfection and effectual inactivation approach to treat microorganisms in aqueous systems. Inactivation of Gram-negative Escherichia coli (E. coli) by generating high-frequency, high-voltage, oxygen (O2) injected and hydrogen peroxide (H2O2) added discharge in water was achieved. The effect of H2O2 dose and oxygen injection rate on electrical characteristics of discharge and E. coli disinfection has been reported. Microbial log reduction dependent on H2O2 addition with O2 injection was observed. The time variation of the inactivation efficiency quantified by the log reduction of the initial E. coli population on the basis of optical density measurement was reported. The analysis of emission spectrum recorded after discharge occurrence illustrated the formation of oxidant species (OH•, H, and O). Interestingly, the results demonstrated that O2 injected and H2O2 added, underwater plasma discharge had fabulous impact on the E. coli sterilization. The oxygen injection notably reduced the voltage needed for generating breakdown in flowing water and escalated the power of discharge pulses. No impact of hydrogen peroxide addition on breakdown voltage was observed. A significant role of oxidant species in bacterial inactivation also has been identified. Furthermore the E. coli survivability in plasma treated water with oxygen injection and hydrogen peroxide addition drastically reduced to zero. The time course study also showed that the retardant effect on E. coli colony multiplication in plasma treated water was favorable, observed after long time. High-frequency underwater plasma discharge based biological applications is technically relevant and would act as baseline data for the development of novel antibacterial processing strategies.

  20. High-frequency underwater plasma discharge application in antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, M. W.; Choi, S.; Lyakhov, K.; Shaislamov, U. [Jeju National University, Department of Nuclear and Energy Engineering (Korea, Republic of); Mongre, R. K.; Jeong, D. K. [Jeju National University, Faculty of Biotechnology (Korea, Republic of); Suresh, R.; Lee, H. J., E-mail: hjlee@jejunu.ac.kr [Jeju National University, Department of Nuclear and Energy Engineering (Korea, Republic of)

    2017-03-15

    Plasma discharge is a novel disinfection and effectual inactivation approach to treat microorganisms in aqueous systems. Inactivation of Gram-negative Escherichia coli (E. coli) by generating high-frequency, high-voltage, oxygen (O{sub 2}) injected and hydrogen peroxide (H{sub 2}O{sub 2}) added discharge in water was achieved. The effect of H{sub 2}O{sub 2} dose and oxygen injection rate on electrical characteristics of discharge and E. coli disinfection has been reported. Microbial log reduction dependent on H{sub 2}O{sub 2} addition with O{sub 2} injection was observed. The time variation of the inactivation efficiency quantified by the log reduction of the initial E. coli population on the basis of optical density measurement was reported. The analysis of emission spectrum recorded after discharge occurrence illustrated the formation of oxidant species (OH{sup •}, H, and O). Interestingly, the results demonstrated that O{sub 2} injected and H{sub 2}O{sub 2} added, underwater plasma discharge had fabulous impact on the E. coli sterilization. The oxygen injection notably reduced the voltage needed for generating breakdown in flowing water and escalated the power of discharge pulses. No impact of hydrogen peroxide addition on breakdown voltage was observed. A significant role of oxidant species in bacterial inactivation also has been identified. Furthermore the E. coli survivability in plasma treated water with oxygen injection and hydrogen peroxide addition drastically reduced to zero. The time course study also showed that the retardant effect on E. coli colony multiplication in plasma treated water was favorable, observed after long time. High-frequency underwater plasma discharge based biological applications is technically relevant and would act as baseline data for the development of novel antibacterial processing strategies.

  1. Low activity of superoxide dismutase and high activity of glutathione reductase in erythrocytes from centenarians

    DEFF Research Database (Denmark)

    Andersen, Helle Raun; Jeune, B; Nybo, H

    1998-01-01

    aged between 60 and 79 years. MEASUREMENTS: enzyme activities of superoxide dismutase (CuZn-SOD), glutathione peroxidase, catalase and glutathione reductase (GR) in erythrocytes. Functional capacity among the centenarians was evaluated by Katz' index of activities of daily living, the Physical...

  2. Enzymatically active high-flux selectively gas-permeable membranes

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Ying-Bing; Cecchi, Joseph L.; Rempe, Susan; FU, Yaqin; Brinker, C. Jeffrey

    2016-01-26

    An ultra-thin, catalyzed liquid transport medium-based membrane structure fabricated with a porous supporting substrate may be used for separating an object species such as a carbon dioxide object species. Carbon dioxide flux through this membrane structures may be several orders of magnitude higher than traditional polymer membranes with a high selectivity to carbon dioxide. Other gases such as molecular oxygen, molecular hydrogen, and other species including non-gaseous species, for example ionic materials, may be separated using variations to the membrane discussed.

  3. The sequence of learning cycle activities in high school chemistry

    Science.gov (United States)

    Abraham, Michael R.; Renner, John W.

    The sequence of the three phases of two high school learning cycles in chemistry was altered in order to: (I ) give insights into the factors which account for the success of the learning cycle, (2) serve as an indirect test of the association between Piaget's theory and the learning cycle, and (3) to compare the learning cycle with traditional instruction. Each of the six sequences (one n o d and five altered) was studied with content and atritudc measures. The outcomes of the study supported the contention that the normal learning cycle sequence is the optimum sequence for achievement of content knowledge.

  4. High Telomerase Activity Correlates with the Stabilities of Genome and DNA Ploidy in Renal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Hideki Izumi

    2002-01-01

    Full Text Available Malignant tumors have telomerase activity, which is thought to play a critical role in tumor growth. However, the relation between telomerase activity and genomic DNA status in tumor cells is poorly understood. In the present study, we examined telomerase activity in 13 clear cell type renal cell carcinomas (CRCCs with similar clinicopathologic features by telomeric repeat amplification protocol assay (TRAP. Based on TRAP assay results, we divided the CRCCs into two groups: a high telomerase activity group and a low/no telomerase activity group. We then analyzed genomic aberration, DNA ploidy, and telomere status in these two groups by comparative genomic hybridization (CGH, laser scanning cytometry (LSC, and telomere-specific fluorescence in situ hybridization (T-FISH, respectively. CGH showed the high telomerase activity group to have fewer genomic changes than the low/no telomerase activity group, which had many genomic aberrations. Moreover, with LSC, DNA diploid cells were found more frequently in the high telomerase activity group than in the low/no telomerase activity group. In addition, T-FISH revealed strong telomere signal intensity in the high telomerase activity group compared with that of the low/no telomerase activity group. These results suggest that telomerase activity is linked to genomic DNA status and that high telomerase activity is associated with genomic stability, DNA ploidy, and telomere length in CRCC.

  5. Highly active catalyst for vinyl acetate synthesis by modified activated carbon

    Institute of Scientific and Technical Information of China (English)

    Chun Yan Hou; Liang Rong Feng; Fa Li Qiu

    2009-01-01

    A new zinc acetate catalyst which was prepared from modified activated carbon exhibited extreme activity towards the synthesis of vinyl acetate. The activated carbon was modified by nitric acid, vitriol and peroxyacetic acid (PAA). The effect on specific area, structure, pH and surface acidity groups of carriers by modification was discussed. Amount of carbonyl and carboxyl groups in activated carbon was increased by peroxyacetic acid treatment. The productivity of the new catalyst was 14.58% higher than that of catalyst prepared using untreated activated carbon. The relationship between amount of carbonyl and carboxyl groups (m) and catalyst productivity (P) was P = 1.83 + 2.26 x 10-3e3.17m. Reaction mechanism was proposed.

  6. Effects of Glycyrrhiza glabra polysaccharides on immune and antioxidant activities in high-fat mice.

    Science.gov (United States)

    Hong, Ying-Kai; Wu, Hua-Tao; Ma, Tao; Liu, Wei-Juan; He, Xue-Jun

    2009-07-01

    The purpose of this study was to investigate the immune and antioxidant activities of Glycyrrhiza glabra polysaccharides (GGP) in rats fed high-fat diet. The experiment was performed on four groups of growing Kunming mice. The results of the experiment showed a statistically significant decrease in serum antioxidant enzyme activities in high-fat group. Administration of GGP dose-dependently significantly enhanced immune and antioxidant enzyme activities in the GGP-treated mice compared to the high-fat model mice. It is concluded that GGP treatment can enhance immune activities, and reduce oxidative stress in high-fat mice.

  7. Early High Tc Activity in Japan: The Franco Rasetti Lecture

    Science.gov (United States)

    Tanaka, Shoji

    2007-03-01

    From 1960 to 1980, R&D of superconductivity in Japan was carried out mainly to improve A15 superconducting wires and magnets. Improvement of wires were made mainly in the National Institute for Metals, and improvements of superconducting magnets were made in the Japan Atomic Energy Research Institute for future nuclear fusion reactors, the National Railway Laboratory for future maglev trains and also in the Electo-Technical Laboratory for MHD generators. I began the research of BPBO in 1975 and at that time the research of oxide superconductors was limited only to my laboratory in the University of Tokyo. During the study of this new superconductor, we learned quite a lot on how to make ceramic samples, how to measure electrical conductivity and magnetic susceptibility at low temperatures. In 1982, Prof. S. Nakajima organized a rather small group for investigating ``New Superconducting Phenomena,'' and I became a member of the group. In 1985, Nakajima expanded the research group to include more than 5 experimentalists and 5 theoreticians. The title of the research was ``New Superconducting Materials'' and the funds came from the Ministry of Education of Japan. In late October, 1986, we followed the first paper of Bednorz and Muller, and immediately found the material includes high temperature superconductor and reported it to the group meeting held in early November. In early December, we confirmed La2-xBaxCuO4 is the real high temperature superconductor, the critical temperature is 28K. I sent a copy of our paper to Prof. Beasley of California and asked to inform this fact to his colleagues. Asahi Shimbun, the biggest newspaper in Japan announced this in its science section, and then many people knew the high temperature superconductor had been discovered. Then many physicists and chemists rushed to this field very quickly and many kinds of materials were synthesized. In the Government, the Ministry of Education, the Ministry of International Trade and Industry

  8. Highly bacterial resistant silver nanoparticles: synthesis and antibacterial activities

    Energy Technology Data Exchange (ETDEWEB)

    Chudasama, Bhupendra, E-mail: bnchudasama@gmail.co [Thapar University, School of Physics and Materials Science (India); Vala, Anjana K.; Andhariya, Nidhi; Mehta, R. V. [Bhavnagar University, Department of Physics (India); Upadhyay, R. V. [Charotar University of Science and Technology, P.D. Patel Institute of Applied Sciences (India)

    2010-06-15

    In this article, we describe a simple one-pot rapid synthesis route to produce uniform silver nanoparticles by thermal reduction of AgNO{sub 3} using oleylamine as reducing and capping agent. To enhance the dispersal ability of as-synthesized hydrophobic silver nanoparticles in water, while maintaining their unique properties, a facile phase transfer mechanism has been developed using biocompatible block co-polymer pluronic F-127. Formation of silver nanoparticles is confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-vis spectroscopy. Hydrodynamic size and its distribution are obtained from dynamic light scattering (DLS). Hydrodynamic size and size distribution of as-synthesized and phase transferred silver nanoparticles are 8.2 {+-} 1.5 nm ({sigma} = 18.3%) and 31.1 {+-} 4.5 nm ({sigma} = 14.5%), respectively. Antimicrobial activities of hydrophilic silver nanoparticles is tested against two Gram positive (Bacillus megaterium and Staphylococcus aureus), and three Gram negative (Escherichiacoli, Proteusvulgaris and Shigellasonnei) bacteria. Minimum inhibitory concentration (MIC) values obtained in the present study for the tested microorganisms are found much better than those reported for commercially available antibacterial agents.

  9. High-resolution molecular line observations of active galaxies

    CERN Document Server

    García-Burillo, S; Usero, A; Gracia-Carpio, J

    2008-01-01

    The study of the content, distribution and kinematics of interstellar gas is a key to understand the origin and maintenance of both starburst and nuclear (AGN) activity in galaxies. The processes involved in AGN fueling encompass a wide range of scales, both spatial and temporal, which have to be studied. Probing the gas flow from the outer disk down to the central engine of an AGN host, requires the use of specific tracers of the interstellar medium adapted to follow the change of phase of the gas as a function of radius. Current mm-interferometers can provide a sharp view of the distribution and kinematics of molecular gas in the circumnuclear disks of galaxies through extensive CO line mapping. As such, CO maps are an essential tool to study AGN feeding mechanisms in the local universe. This is the scientific driver of the NUclei of GAlaxies (NUGA) survey, whose latest results are here reviewed. On the other hand, the use of specific molecular tracers of the dense gas phase can probe the feedback influence...

  10. Toward high-dynamic active mirrors for LGS refocusing systems

    Science.gov (United States)

    Hugot, Emmanuel; Madec, Fabrice; Vives, Sébastien; Ferrari, Marc; Le Mignant, David; Cuby, Jean Gabriel

    2010-07-01

    In the frame of the E-ELT-EAGLE instrument phase A studies, we designed a convex VCM able to compensate for the focus variation on the Laser Guide Star (LGS) wavefront sensor, due to the elevation of the telescope and the fixed sodium layer altitude. We present an original optical design including this active convex mirror, providing a large sag variation on a spherical surface with a 120mm clear aperture, with an optical quality better than lambda/5 RMS up to 820μm of sag and better than lambda/4 RMS up to 1000μm of sag. Finite element analysis (FEA) allowed an optimisation of the mirror's variable thickness distribution to compensate for geometrical and material non linearity. Preliminary study of the pre-stressing has also been performed by FEA, showing that a permanent deformation remains after removal of the loads. Results and comparison with the FEA are presented in the article of F.Madec et al (AS10-7736-119, this conference), with an emphasis on the system approach.

  11. Revisiting the question: Does high-latitude solar activity lead low-latitude solar activity in time phase?

    Energy Technology Data Exchange (ETDEWEB)

    Kong, D. F.; Qu, Z. N. [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Guo, Q. L., E-mail: kdf@ynao.ac.cn [College of Mathematics Physics and Information Engineering, Jiaxing University, Jiaxing 314001 (China)

    2014-05-01

    Cross-correlation analysis and wavelet transform methods are used to investigate whether high-latitude solar activity leads low-latitude solar activity in time phase or not, using the data of the Carte Synoptique solar filaments archive from 1919 March to 1989 December. From the cross-correlation analysis, high-latitude solar filaments have a time lead of 12 Carrington solar rotations with respect to low-latitude ones. Both the cross-wavelet transform and wavelet coherence indicate that high-latitude solar filaments lead low-latitude ones in time phase. Furthermore, low-latitude solar activity is better correlated with high-latitude solar activity of the previous cycle than with that of the following cycle, which is statistically significant. Thus, the present study confirms that high-latitude solar activity in the polar regions is indeed better correlated with the low-latitude solar activity of the following cycle than with that of the previous cycle, namely, leading in time phase.

  12. 78 FR 56222 - Agency Information Collection Activities; Comment Request; Highly Qualified Teachers Clearance

    Science.gov (United States)

    2013-09-12

    ... Agency Information Collection Activities; Comment Request; Highly Qualified Teachers Clearance AGENCY... notice will be considered public records. Title of Collection: Highly Qualified Teachers Clearance OMB... disadvantaged students) are taught by teachers participating in an alternative route to certification...

  13. Active Galactic Nuclei: Sources for ultra high energy cosmic rays?

    Energy Technology Data Exchange (ETDEWEB)

    Biermann, Peter L. [MPI for Radioastronomy, Bonn (Germany); Dept. of Phys. and Astron., Univ. of Bonn (Germany); Dept. of Phys. and Astr., Univ. of Alabama, Tuscaloosa, AL (United States); Dept. of Phys., Univ. of Alabama at Huntsville, AL (United States); Inst. Nucl. Phys. FZ, Karlsruhe Inst. of Techn. (KIT) (Germany); Becker, Julia K. [Institution foer Fysik, Goeteborgs Univ. (Sweden); Dept. of Phys., Univ. Dortmund, Dortmund (Germany); Caramete, Laurentiu [MPI for Radioastronomy, Bonn (Germany); Institute for Space Studies, Bucharest (Romania); Curutiu, Alex [MPI for Radioastronomy, Bonn (Germany); Engel, Ralph [Inst. Nucl. Phys. FZ, Karlsruhe Inst. of Techn. (KIT) (Germany); Falcke, Heino [Dept. of Astrophys., IMAP, Radboud Univ., Nijmegen (Netherlands); ASTRON, Dwingeloo (Netherlands); Gergely, Laszlo A. [Dept. Appl. Sci., London South Bank University (United Kingdom); Dept. of Theoret. and Exp. Phys., Univ. of Szeged, Szeged (Hungary); Isar, P. Gina [Inst. Nucl. Phys. FZ, Karlsruhe Inst. of Techn. (KIT) (Germany); Institute for Space Studies, Bucharest (Romania); Maris, Ioana C. [Inst. Nucl. Phys. FZ, Karlsruhe Inst. of Techn. (KIT) (Germany); Meli, Athina [Physik. Inst. Univ. Erlangen-Nuernberg (Germany); Kampert, Karl-Heinz [Phys. Dept., Univ. Wuppertal (Germany); Stanev, Todor [Bartol Research Inst., Univ. of Delaware, Newark, DE (United States); Tascau, Oana [Phys. Dept., Univ. Wuppertal (Germany); Zier, Christian [MPI for Radioastronomy, Bonn (Germany); Raman Res. Inst., Bangalore (India)

    2009-05-15

    The origin of ultra high energy cosmic rays promises to lead us to a deeper understanding of the structure of matter. This is possible through the study of particle collisions at center-of-mass energies in interactions far larger than anything possible with the Large Hadron Collider, albeit at the substantial cost of no control over the sources and interaction sites. For the extreme energies we have to identify and understand the sources first, before trying to use them as physics laboratories. Here we describe the current stage of this exploration. The most promising contenders as sources are radio galaxies and gamma ray bursts. The sky distribution of observed events yields a hint favoring radio galaxies. Key in this quest are the intergalactic and galactic magnetic fields, whose strength and structure are not yet fully understood. Current data and statistics do not yet allow a final judgement. We outline how we may progress in the near future.

  14. High power density aqueous hybrid supercapacitor combining activated carbon and highly conductive spinel cobalt oxide

    Science.gov (United States)

    Godillot, G.; Taberna, P.-L.; Daffos, B.; Simon, P.; Delmas, C.; Guerlou-Demourgues, L.

    2016-11-01

    The remarkable electrochemical behavior of complete activated carbon/cobalt oxide cells is reported in the present work. Among the various weight ratios between the positive and negative electrodes evaluated, the best features are obtained with an overcapacitive cobalt oxide electrode. The energy densities obtained by this system (20 Wh kg-1 for a power density of 209 W kg-1) are twice higher than those measured for a activated carbon/activated carbon symmetric cell, in the same operating conditions. With discharge capacities around 62 F g-1, this system is among the best ones reported in the literature for this category.

  15. Highly Active Ice Nuclei from Tree Leaf Litters Retain Activity for Decades

    Science.gov (United States)

    Schnell, R. C.; Hill, T. C. J.

    2015-12-01

    Biogenic ice nuclei (IN) studied since the 1960s were first observed in tree leaf litters, in a few bacteria species and later in fungi and lichens. Recently, viable IN bacteria in precipitation have been used as a metric of their possible role in precipitation formation. Although bacterial IN activity is deactivated by a variety of common environmental stresses, we present data showing that IN found in a potpourri of decayed plant leaves, bacteria, molds and fungi etc. in plant litters are exceptionally stable and active over decades while in storage. As such, their atmospheric IN potential is worthy of further study due to their environmental persistence. In August 1970 litter collected in a grove of deciduous trees near Red Deer, AB, Canada was tested for IN (drop freezing technique). The sample initiated ice at -4C with 109 IN per gram of litter active at -10C. A few kilograms were stored in a plastic bag and tested every few years for IN content; the IN activity remained essentially unchanged over 40 years. In 2011, litter collected in the same grove had the same IN activity as the sample tested over the intervening 40 years. Boiling a gram sample of this litter in 100 grams of water deactivated 99 % of the IN activity down to -13C. None of 88 different bacteria cultures several of which appeared to Pseudomonads (common IN producing bacteria) from the fresh litter produced any active IN. A sample of the litter was placed on the top of a 15 cm column of laboratory grade kaolin and water dripped onto the litter. Ten days later the water reached the bottom of the column. The kaolin was dried and tested for IN. The prior essentially IN free kaolin now exhibited IN activity at -4C with 105 IN active at -10C. The litter exposed kaolin retained the IN activity for 25 years. Baking the kaolin removed the active IN. This suggests that IN activity attributed to kaolin particles sometimes seen at the nucleus of snow crystals could be of biological origin.

  16. [Effects of activator and activator + anterior high-pull headgear on the growth direction of Class 2 cases].

    Science.gov (United States)

    Uner, O; Akkaya, S; Buyruk, F

    1989-04-01

    In this study which the effects of activator and activator + anterior high-pull headgear on the growth direction of skeletal class 2 cases for a period of approximately 9 months; 33 cases having a mean age of 10.59 years; ANB angles 4.5 degrees and over were studied. Activator treatment has been applied to the 11 of the 22 treatment cases, the others have had the activator + anterior high-pull headgear treatment. The control group, 11 patients, has only been observed in terms of the growth and development without having any treatment. At the end of the study; it was found that the decrease in ANB angle and the increase in SL dimension in the treatment groups; the increase in anterior lower face height in the activator group and the increase in the ratio of posterior to anterior face height were statistically significant.

  17. Synthesis of trapezohedral indium oxide nanoparticles with high-index {211} facets and high gas sensing activity.

    Science.gov (United States)

    Han, Xiguang; Han, Xiao; Sun, Linqiang; Gao, Shengguang; Li, Liang; Kuang, Qin; Xie, Zhaoxiong; Wang, Chao

    2015-06-14

    Nanocrystals with high-index facets usually exhibit higher catalytic activities than those with only low-index facets. Trapezohedron-shaped (TS) In2O3 particles with exposed high-index {211} facets were successfully synthesized in an oleic acid (OA) and trioctylamine (TOA) system. It has been demonstrated that the gas sensing activity of TS In2O3 particles with exposed high-index {211} facets is higher than that of octahedron-shaped In2O3 particles with exposed low-index {111} facets.

  18. A new shunt DC active filter of power supply in a steady high magnetic field facility

    Institute of Scientific and Technical Information of China (English)

    WANG Lei; LIU Xiao-Ning; WANG Can

    2011-01-01

    A DC active power filter is an indispensable part in a high power and high stability power supply system, especially in the power supply system of the Steady High Magnetic Field Facility, which requires that the current ripple should be limited to 50 parts per million. In view of the disadvantages of the series DC active power filter and shunt Pulse Width Modulation DC active filter, this paper puts forward a novel DC active filter by combining the advantages of the transistor regulator and the shunt type. The structure and principle of the new shunt linear active filter are introduced. Meanwhile, the design of several key components that construct the new shunt linear active filter is also analyzed. The simulation model and an experimental prototype of the shunt linear active filter are developed, and the results verify that the parameter design is reasonable and the shunt active filter has a good filter effect.

  19. Lifecycle Prognostics Architecture for Selected High-Cost Active Components

    Energy Technology Data Exchange (ETDEWEB)

    N. Lybeck; B. Pham; M. Tawfik; J. B. Coble; R. M. Meyer; P. Ramuhalli; L. J. Bond

    2011-08-01

    There are an extensive body of knowledge and some commercial products available for calculating prognostics, remaining useful life, and damage index parameters. The application of these technologies within the nuclear power community is still in its infancy. Online monitoring and condition-based maintenance is seeing increasing acceptance and deployment, and these activities provide the technological bases for expanding to add predictive/prognostics capabilities. In looking to deploy prognostics there are three key aspects of systems that are presented and discussed: (1) component/system/structure selection, (2) prognostic algorithms, and (3) prognostics architectures. Criteria are presented for component selection: feasibility, failure probability, consequences of failure, and benefits of the prognostics and health management (PHM) system. The basis and methods commonly used for prognostics algorithms are reviewed and summarized. Criteria for evaluating PHM architectures are presented: open, modular architecture; platform independence; graphical user interface for system development and/or results viewing; web enabled tools; scalability; and standards compatibility. Thirteen software products were identified and discussed in the context of being potentially useful for deployment in a PHM program applied to systems in a nuclear power plant (NPP). These products were evaluated by using information available from company websites, product brochures, fact sheets, scholarly publications, and direct communication with vendors. The thirteen products were classified into four groups of software: (1) research tools, (2) PHM system development tools, (3) deployable architectures, and (4) peripheral tools. Eight software tools fell into the deployable architectures category. Of those eight, only two employ all six modules of a full PHM system. Five systems did not offer prognostic estimates, and one system employed the full health monitoring suite but lacked operations and

  20. Dimerization in Highly Concentrated Solutions of Phosphoimidazolide Activated Monomucleotides

    Science.gov (United States)

    Kanavarioti, Anastassia

    1997-08-01

    Phosphoimidazolide activated ribomononucleotides (*pN) are useful substrates for the non-enzymatic synthesis of polynucleotides. However, dilute neutral aqueous solutions of *pN typically yield small amounts of dimers and traces of polymers; most of *pN hydrolyzes to yield nucleoside 5'-monophosphate. Here we report the self-condensation of nucleoside 5'-phosphate 2-methylimidazolide (2-MeImpN with N = cytidine, uridine or guanosine) in the presence of Mg2+ in concentrated solutions, such as might have been found in an evaporating lagoon on prebiotic Earth. The product distribution indicates that oligomerization is favored at the expense of hydrolysis. At 1.0 M, 2-MeImpU and 2-MeImpC produce about 65% of oligomers including 4% of the 3',5'-linked dimer. Examination of the product distribution of the three isomeric dimers in a self-condensation allows identification of reaction pathways that lead to dimer formation. Condensations in a concentrated mixture of all three nucleotides (U,C,G mixtures) is made possible by the enhanced solubility of 2-MeImpG in such mixtures. Although percent yield of internucleotide linked dimers is enhanced as a function of initial monomer concentration, pyrophosphate dimer yields remain practically unchanged at about 20% for 2-MeImpU, 16% for 2-MeImpC and 25% of the total pyrophosphate in the U,C,G mixtures. The efficiency by which oligomers are produced in these concentrated solutions makes the evaporating lagoon scenario a potentially interesting medium for the prebiotic synthesis of dimers and short RNAs.

  1. Highly antioxidant carotene-lipid nanocarriers: synthesis and antibacterial activity

    Science.gov (United States)

    Lacatusu, Ioana; Badea, Nicoleta; Ovidiu, Oprea; Bojin, Dionezie; Meghea, Aurelia

    2012-06-01

    The objective of this study was to explore the potential of two natural oils (squalene—Sq and grape seed oil—GSO) to prepare biocompatible antioxidant nanostructured lipid carriers—NLCs as a safety and protective formulation for sensitive β-carotene. For this purpose different oil-in-water nanoemulsions stabilized by a combination of alkylpolyoxy ethylene sorbitans, lecithin and a block copolymer, were prepared using a melt high-shear homogenization process. The physico-chemical characteristics of the carotene-loaded NLCs were firstly investigated in detail. The smaller lipid nanoparticles have been obtained by using Tween 20 as main non-ionic surfactant, with average diameters of about 85 nm for GSO and 89 nm for Sq, with a polydispersity index Escherichia coli bacteria. The antibacterial analysis shown that loaded-NLCs develop an effective inhibition zone against bacteria growth and it was dependent in a higher extent on the liquid lipid and carotene concentrations than on their particle size.

  2. Feeding habits of athletes with high physical activity

    Directory of Open Access Journals (Sweden)

    E. A. Mazurenko

    2016-01-01

    Full Text Available The article describes the features of construction of specialized foods for sportsmen, members of Amateur and professional teams to play Rugby. The relevance of the study lies in the fact that so far not established a unified recommendations on diets and nutrition regimes of the Rugby players. We are committed to the solution of the time-consuming assessment of individual needs athletes Rugby players in nutrients. For the Rugby player is especially important qualitative composition of protein intake. Sports doctors and coaches recommend rational diet of the Rugby players with the prevalence of essential amino acids involved in the biosynthesis of neurotransmitters. The highest loads on the body of a Rugby player due to the fact that in the training sessions of Rugby players includes power elements used in elite military units and police units in order to develop collective interactions in hard conditions. They include elements of weightlifting, intense agility and martial arts and martial arts. The special task of organizing the diet of Rugby players is the use of high carbohydrate diets to prevent chronic lack of energy during training and during competitions. The diet should be an optimal content of products from cereal crops, with relatively little protein and fat. You need to replenish energy stores by eating balanced chemical with the rod, avoiding long breaks and including protein and carbohydrate foods. For quality control using modern gas and spectrophotometric devices Institute of Food and Processing Industry of the Kuban State University of Technology. Key findings include the development of the diets of athletes in team rugby Kuban State University and some of the specialized vegetable and meat products, "rugby" and "Sport".

  3. Successful Geoscience Pipeline Activities for High School and College Students

    Science.gov (United States)

    Furman, T.; Fail, C. F.; Adewumi, M.; Bralower, T.; Guertin, L.

    2004-12-01

    The proportion of African-American students in the College of Earth and Mineral Sciences (EMS) at Penn State is 3.3 percent, only slightly lower than the overall University Park campus proportion of 4 percent. Retention rates within EMS are excellent; a recent survey found that EMS ranks highest in student satisfaction overall at the University Park campus. Our goal to increase diversity in EMS disciplines requires us to attract new students to Penn State rather than recruiting from other areas within the institution. We have implemented three programs that appear successful in this regard, and are thus likely to form a viable pipeline from high school through graduate school. These programs operate at a college-wide level and are co-sponsored by AESEDA (Alliance for Earth Science, Engineering and Development in Africa). SEEMS (Summer Experience in EMS) is a partnership with Upward Bound Math and Science, adding 30 hours of directed research to their existing enrichment program. Students identified in 9th grade spend 6 weeks each summer in residence at PSU, where they receive classroom instruction in core academic areas in addition to a group research project led by faculty and graduate students. SEEMS students are likely PSU recruits: all are accepted to college, 85 percent plan to attend college within PA, and all have strong family support for education as well as for careers in EMS. Pre- and post-experience surveys indicate strong positive changes in perception of EMS careers, particularly with regard to levels of intellectual challenge and starting salary. We maintain personal contact with these students and encourage them to attend PSU when they graduate. SROP (Summer Research Opportunity Program) is administered by the Committee on Institutional Cooperation, the academic arm of the Big 10, and provides residential research internships for students from HBCU and MSI campuses. EMS participates in SROP by funding research interns and providing strong individual

  4. Highly porous activated carbons from resource-recovered Leucaena leucocephala wood as capacitive deionization electrodes.

    Science.gov (United States)

    Hou, Chia-Hung; Liu, Nei-Ling; Hsi, Hsing-Cheng

    2015-12-01

    Highly porous activated carbons were resource-recovered from Leucaena leucocephala (Lam.) de Wit. wood through combined chemical and physical activation (i.e., KOH etching followed by CO2 activation). This invasive species, which has severely damaged the ecological economics of Taiwan, was used as the precursor for producing high-quality carbonaceous electrodes for capacitive deionization (CDI). Carbonization and activation conditions strongly influenced the structure of chars and activated carbons. The total surface area and pore volume of activated carbons increased with increasing KOH/char ratio and activation time. Overgasification induced a substantial amount of mesopores in the activated carbons. In addition, the electrochemical properties and CDI electrosorptive performance of the activated carbons were evaluated; cyclic voltammetry and galvanostatic charge/discharge measurements revealed a typical capacitive behavior and electrical double layer formation, confirming ion electrosorption in the porous structure. The activated-carbon electrode, which possessed high surface area and both mesopores and micropores, exhibited improved capacitor characteristics and high electrosorptive performance. Highly porous activated carbons derived from waste L. leucocephala were demonstrated to be suitable CDI electrode materials.

  5. Application of an active attachment model as a high-throughput demineralization biofilm model

    NARCIS (Netherlands)

    Silva, T.C.; Pereira, A.F.F.; Exterkate, R.A.M.; Bagnato, V.S.; Buzalaf, M.A.R.; de A.M. Machado, M.A.; ten Cate, J.M.; Crielaard, W.; Deng, D.M.

    2012-01-01

    Objectives To investigate the potential of an active attachment biofilm model as a high-throughput demineralization biofilm model for the evaluation of caries-preventive agents. Methods Streptococcus mutans UA159 biofilms were grown on bovine dentine discs in a high-throughput active attachment mode

  6. High surface area activated carbon prepared from cassava peel by chemical activation.

    Science.gov (United States)

    Sudaryanto, Y; Hartono, S B; Irawaty, W; Hindarso, H; Ismadji, S

    2006-03-01

    Cassava is one of the most important commodities in Indonesia, an agricultural country. Cassava is one of the primary foods in our country and usually used for traditional food, cake, etc. Cassava peel is an agricultural waste from the food and starch processing industries. In this study, this solid waste was used as the precursor for activated carbon preparation. The preparation process consisted of potassium hydroxide impregnation at different impregnation ratio followed by carbonization at 450-750 degrees C for 1-3 h. The results revealed that activation time gives no significant effect on the pore structure of activated carbon produced, however, the pore characteristic of carbon changes significantly with impregnation ratio and carbonization temperature. The maximum surface area and pore volume were obtained at impregnation ratio 5:2 and carbonization temperature 750 degrees C.

  7. A two-layered approach to recognize high-level human activities

    NARCIS (Netherlands)

    N. Hu; G. Englebienne; B. Kröse

    2014-01-01

    Automated human activity recognition is an essential task for Human Robot Interaction (HRI). A successful activity recognition system enables an assistant robot to provide precise services. In this paper, we present a two-layered approach that can recognize sub-level activities and high-level activi

  8. A High-affinity Activator of G551D-CFTR Chloride Channel Identified By High Throughput Screening

    Institute of Scientific and Technical Information of China (English)

    ZHAO Lu; HE Cheng-yan; LIU Yan-li; ZHOU Hong-lan; ZHOU Jin-song; SHANG De-jing; YANG Hong

    2004-01-01

    A stably transfected CHO cell line coexpressing G551D-CFTR and iodide-sensitive yellow fluorescent protein mutant EYFP-H148Q-I152L was successfully established and used as assay model to identify small-molecule activators of G551D-CFTR chloride channel from 100000 diverse combinatorial compounds by high throughput screening on a customized Beckman robotic system. A bicyclooctane compound was identified to activate G551D-CFTR chloride channel with high-affinity(Kd=1.8 μmol/L). The activity of the bicyclooctane compound is G551D-CFTR-specific, reversible and non-toxic. The G551D-CFTR activator may be useful as a tool to study the mutant G551D-CFTR chloride channel structure and transport properties and as a candidate drug to cure cystic fibrosis caused by G551D-CFTR mutation.

  9. Oxidative stress plays a role in high glucose-induced activation of pancreatic stellate cells

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Gyeong Ryul; Lee, Esder; Chun, Hyun-Ji; Yoon, Kun-Ho; Ko, Seung-Hyun; Ahn, Yu-Bae; Song, Ki-Ho, E-mail: kihos@catholic.ac.kr

    2013-09-20

    Highlights: •High glucose increased production of reactive oxygen species in cultured pancreatic stellate cells. •High glucose facilitated the activation of these cells. •Antioxidant treatment attenuated high glucose-induced activation of these cells. -- Abstract: The activation of pancreatic stellate cells (PSCs) is thought to be a potential mechanism underlying islet fibrosis, which may contribute to progressive β-cell failure in type 2 diabetes. Recently, we demonstrated that antioxidants reduced islet fibrosis in an animal model of type 2 diabetes. However, there is no in vitro study demonstrating that high glucose itself can induce oxidative stress in PSCs. Thus, PSCs were isolated and cultured from Sprague Dawley rats, and treated with high glucose for 72 h. High glucose increased the production of reactive oxygen species. When treated with high glucose, freshly isolated PSCs exhibited myofibroblastic transformation. During early culture (passage 1), PSCs treated with high glucose contained an increased number of α-smooth muscle actin-positive cells. During late culture (passages 2–5), PSCs treated with high glucose exhibited increases in cell proliferation, the expression of fibronectin and connective tissue growth factor, release of interleukin-6, transforming growth factor-β and collagen, and cell migration. Finally, the treatment of PSCs with high glucose and antioxidants attenuated these changes. In conclusion, we demonstrated that high glucose increased oxidative stress in primary rat PSCs, thereby facilitating the activation of these cells, while antioxidant treatment attenuated high glucose-induced PSC activation.

  10. Highly Efficient, Simplified, Solution-Processed Thermally Activated Delayed-Fluorescence Organic Light-Emitting Diodes.

    Science.gov (United States)

    Kim, Young-Hoon; Wolf, Christoph; Cho, Himchan; Jeong, Su-Hun; Lee, Tae-Woo

    2016-01-27

    Highly efficient, simplified, solution-processed thermally activated delayed-fluorescence organic light-emitting diodes can be realized by using pure-organic thermally activated delayed fluorescence emitters and a multifunctional buffer hole-injection layer, in which high EQE (≈24%) and current efficiency (≈73 cd A(-1) ) are demonstrated. High-efficiency fluorescence red-emitting and blue-emitting devices can also be fabricated in this manner.

  11. Effect of Activating Agent on the Preparation of Bamboo-Based High Surface Area Activated Carbon by Microwave Heating

    Science.gov (United States)

    Xia, Hongying; Wu, Jian; Srinivasakannan, Chandrasekar; Peng, Jinhui; Zhang, Libo

    2016-06-01

    The present work attempts to convert bamboo into a high surface area activated carbon via microwave heating. Different chemical activating agents such as KOH, NaOH, K2CO3 and Na2CO3 were utilized to identify a most suitable activating agent. Among the activating agents tested KOH was found to generate carbon with the highest porosity and surface area. The effect of KOH/C ratio on the porous nature of the activated carbon has been assessed. An optimal KOH/C ratio of 4 was identified, beyond which the surface area as well as the pore volume were found to decrease. At the optimized KOH/C ratio the surface area and the pore volume were estimated to be 3,441 m2/g and 2.093 ml/g, respectively, with the significant proportion of which being microporous (62.3%). Activated carbon prepared under the optimum conditions was further characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Activated carbons with so high surface area and pore volume are very rarely reported, which could be owed to the nature of the precursor and the optimal conditions of mixture ratio adopted in the present work.

  12. High salt reduces the activation of IL-4- and IL-13-stimulated macrophages.

    Science.gov (United States)

    Binger, Katrina J; Gebhardt, Matthias; Heinig, Matthias; Rintisch, Carola; Schroeder, Agnes; Neuhofer, Wolfgang; Hilgers, Karl; Manzel, Arndt; Schwartz, Christian; Kleinewietfeld, Markus; Voelkl, Jakob; Schatz, Valentin; Linker, Ralf A; Lang, Florian; Voehringer, David; Wright, Mark D; Hubner, Norbert; Dechend, Ralf; Jantsch, Jonathan; Titze, Jens; Müller, Dominik N

    2015-11-01

    A high intake of dietary salt (NaCl) has been implicated in the development of hypertension, chronic inflammation, and autoimmune diseases. We have recently shown that salt has a proinflammatory effect and boosts the activation of Th17 cells and the activation of classical, LPS-induced macrophages (M1). Here, we examined how the activation of alternative (M2) macrophages is affected by salt. In stark contrast to Th17 cells and M1 macrophages, high salt blunted the alternative activation of BM-derived mouse macrophages stimulated with IL-4 and IL-13, M(IL-4+IL-13) macrophages. Salt-induced reduction of M(IL-4+IL-13) activation was not associated with increased polarization toward a proinflammatory M1 phenotype. In vitro, high salt decreased the ability of M(IL-4+IL-13) macrophages to suppress effector T cell proliferation. Moreover, mice fed a high salt diet exhibited reduced M2 activation following chitin injection and delayed wound healing compared with control animals. We further identified a high salt-induced reduction in glycolysis and mitochondrial metabolic output, coupled with blunted AKT and mTOR signaling, which indicates a mechanism by which NaCl inhibits full M2 macrophage activation. Collectively, this study provides evidence that high salt reduces noninflammatory innate immune cell activation and may thus lead to an overall imbalance in immune homeostasis.

  13. 76 FR 30391 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; High Growth...

    Science.gov (United States)

    2011-05-25

    ... Activities; Submission for OMB Review; Comment Request; High Growth and Community-Based Job Training Grants... Administration (ETA) sponsored information collection request (ICR) titled, ``High Growth and Community-Based Job... INFORMATION: This information collection request implements reporting requirements for High Growth Job...

  14. Factors Influencing Middle and High Schools' Active Parental Consent Return Rates

    Science.gov (United States)

    Ji, Peter Y.; Pokorny, Steven B.; Jason, Leonard A.

    2004-01-01

    The authors examined factors influencing the return rates for attempting to collect active parental consent forms from 21,123 students in the 7th through 10th grades in 41 middle and high schools. Overall return rates from middle schools were higher than from high schools. Schools that offered high levels of staff support for collecting consent…

  15. Inquiry-Based Laboratory Activities in Electrochemistry: High School Students' Achievements and Attitudes

    Science.gov (United States)

    Sesen, Burcin Acar; Tarhan, Leman

    2013-01-01

    This study aimed to investigate the effects of inquiry-based laboratory activities on high school students' understanding of electrochemistry and attitudes towards chemistry and laboratory work. The participants were 62 high school students (average age 17 years) in an urban public high school in Turkey. Students were assigned to experimental (N =…

  16. Highly reliable high-power superluminescent diodes with three single-mode active channels

    Science.gov (United States)

    Andreeva, E. V.; Il'chenko, S. N.; Kurnyavko, Yu V.; Luk'yanov, V. N.; Shidlovskii, V. R.; Yakubovich, S. D.

    2016-07-01

    We report superluminescent diodes (SLDs) with three ridged active channels, each having a width of 3.5 μm, based on one 'bulk' and two quantum-well heterostructures. At a cw output power greater than 100 mW, the emission spectra of these SLDs possess a quasi-Gaussian shape with centre wavelengths near 840, 860 and 1060 nm and widths about 15, 25 and 40 nm, respectively. In the above operating conditions, the median service life of the SLDs amounted to approximately 50000, 25000 and more than 60000 h, respectively.

  17. New Activated Carbon with High Thermal Conductivity and Its Microwave Regeneration Performance

    Institute of Scientific and Technical Information of China (English)

    GU Xuexian; SU Zhanjun; XI Hongxia

    2016-01-01

    Using a walnut shell as a carbon source and ZnCl2 as an activating agent, we resolved the temperature gradient problems of activated carbon in the microwave desorption process. An appropriate amount of silicon carbide was added to prepare the composite activated carbon with high thermal conductivity while developing VOC adsorption-microwave regeneration technology. The experimental results show that the coefficient of thermal conductivity of SiC-AC is three times as much as those of AC and SY-6. When microwave power was 480 W in its microwave desorption , the temperature of the bed thermal desorption was 10℃ to 30℃below that of normal activated carbon prepared in our laboratory. The toluene desorption activation energy was 16.05 kJ∙mol-1, which was 15% less than the desorption activation energy of commercial activated carbon. This study testified that the process could maintain its high adsorption and regeneration desorption performances.

  18. A Clinical Drug Library Screen Identifies Tosufloxacin as Being Highly Active against Staphylococcus aureus Persisters

    Directory of Open Access Journals (Sweden)

    Hongxia Niu

    2015-07-01

    Full Text Available To identify effective compounds that are active against Staphylococcus aureus (S. aureus persisters, we screened a clinical drug library consisting of 1524 compounds and identified six drug candidates that had anti-persister activity: tosufloxacin, clinafloxacin, sarafloxacin, doxycycline, thiostrepton, and chlorosalicylanilide. Among them, tosufloxacin had the highest anti-persister activity, which could completely eradicate S. aureus persisters within 2 days in vitro. Clinafloxacin ranked the second with very few persisters surviving the drug exposure. Interestingly, we found that both tosufloxacin and trovafloxacin that had high activity against persisters contained at the N-1 position the 2,4-difluorophenyl group, which is absent in other less active quinolones and may be associated with the high anti-persister activity. Further studies are needed to evaluate tosufloxacin in animal models and to explain its unique activity against bacterial persisters. Our findings may have implications for improved treatment of persistent bacterial infections.

  19. A facile reflux procedure to increase active surface sites form highly active and durable supported palladium@platinum bimetallic nanodendrites

    Science.gov (United States)

    Wang, Qin; Li, Yingjun; Liu, Baocang; Xu, Guangran; Zhang, Geng; Zhao, Qi; Zhang, Jun

    2015-11-01

    A series of well-dispersed bimetallic Pd@Pt nanodendrites uniformly supported on XC-72 carbon black are fabricated by using different capping agents. These capping agents are essential for the branched morphology control. However, the surfactant adsorbed on the nanodendrites surface blocks the access of reactant molecules to the active surface sites, and the catalytic activities of these bimetallic nanodendrites are significantly restricted. Herein, a facile reflux procedure to effectively remove the capping agent molecules without significantly affecting their sizes is reported for activating supported nanocatalysts. More significantly, the structure and morphology of the nanodendrites can also be retained, enhancing the numbers of active surface sites, catalytic activity and stability toward methanol and ethanol electro-oxidation reactions. The as-obtained hot water reflux-treated Pd@Pt/C catalyst manifests superior catalytic activity and stability both in terms of surface and mass specific activities, as compared to the untreated catalysts and the commercial Pt/C and Pd/C catalysts. We anticipate that this effective and facile removal method has more general applicability to highly active nanocatalysts prepared with various surfactants, and should lead to improvements in environmental protection and energy production.

  20. A Class of High-affinity Bicyclooctane G551D-CFTR Activators Identified by High Throughput Screening

    Institute of Scientific and Technical Information of China (English)

    HE Cheng-yan; ZHAO Lu; LIU Yan-li; XU Li-na; SHANG De-jing; YANG Hong

    2004-01-01

    The glycine-to-aspartic acid missense mutation at the codon 551(G551D) of the cystic fibrosis transmembrane conductance regulator(CFTR) is one of the five most frequent cystic fibrosis(CF) mutations associated with a severe CF phenotype. To explore the feasibility of pharmacological correction of disrupted activation of CFTR chloride channel caused by G551D mutation, we developed a halide-sensitive fluorescence miniassay for G551D-CFTR in Fisher rat thyroid(FRT) epithelial cells for the discovery of novel activators of G551D-CFTR. A class of bicyclooctane small molecule compounds that efficiently stimulate G551D-CFTR chloride channel activity was identified by high throughput screening via the FRT cell-based assay. This class of compounds selectively activates G551D-CFTR with a high affinity, whereas little effect of the compounds on wildtype CFTR can be seen. The discovery of a class of bicyclooctane G551D-CFTR activators will permit the analysis of structure-activity relationship of the compounds to identify ideal leads for in vivo therapeutic studies.

  1. High throughput screens yield small molecule inhibitors of Leishmania CRK3:CYC6 cyclin-dependent kinase.

    Directory of Open Access Journals (Sweden)

    Roderick G Walker

    Full Text Available BACKGROUND: Leishmania species are parasitic protozoa that have a tightly controlled cell cycle, regulated by cyclin-dependent kinases (CDKs. Cdc2-related kinase 3 (CRK3, an essential CDK in Leishmania and functional orthologue of human CDK1, can form an active protein kinase complex with Leishmania cyclins CYCA and CYC6. Here we describe the identification and synthesis of specific small molecule inhibitors of bacterially expressed Leishmania CRK3:CYC6 using a high throughput screening assay and iterative chemistry. We also describe the biological activity of the molecules against Leishmania parasites. METHODOLOGY/PRINCIPAL FINDINGS: In order to obtain an active Leishmania CRK3:CYC6 protein kinase complex, we developed a co-expression and co-purification system for Leishmania CRK3 and CYC6 proteins. This active enzyme was used in a high throughput screening (HTS platform, utilising an IMAP fluorescence polarisation assay. We carried out two chemical library screens and identified specific inhibitors of CRK3:CYC6 that were inactive against the human cyclin-dependent kinase CDK2:CycA. Subsequently, the best inhibitors were tested against 11 other mammalian protein kinases. Twelve of the most potent hits had an azapurine core with structure activity relationship (SAR analysis identifying the functional groups on the 2 and 9 positions as essential for CRK3:CYC6 inhibition and specificity against CDK2:CycA. Iterative chemistry allowed synthesis of a number of azapurine derivatives with one, compound 17, demonstrating anti-parasitic activity against both promastigote and amastigote forms of L. major. Following the second HTS, 11 compounds with a thiazole core (active towards CRK3:CYC6 and inactive against CDK2:CycA were tested. Ten of these hits demonstrated anti-parasitic activity against promastigote L. major. CONCLUSIONS/SIGNIFICANCE: The pharmacophores identified from the high throughput screens, and the derivatives synthesised, selectively

  2. Active Control of Flow Separation on a High-Lift System with Slotted Flap at High Reynolds Number

    Science.gov (United States)

    Khodadoust, Abdollah; Washburn, Anthony

    2007-01-01

    The NASA Energy Efficient Transport (EET) airfoil was tested at NASA Langley's Low- Turbulence Pressure Tunnel (LTPT) to assess the effectiveness of distributed Active Flow Control (AFC) concepts on a high-lift system at flight scale Reynolds numbers for a medium-sized transport. The test results indicate presence of strong Reynolds number effects on the high-lift system with the AFC operational, implying the importance of flight-scale testing for implementation of such systems during design of future flight vehicles with AFC. This paper describes the wind tunnel test results obtained at the LTPT for the EET high-lift system for various AFC concepts examined on this airfoil.

  3. Self-controlled feedback facilitates motor learning in both high and low activity individuals

    Directory of Open Access Journals (Sweden)

    Jeffrey T. Fairbrother

    2012-08-01

    Full Text Available The purpose of this study was to determine if high and low activity individuals differed in terms of the effects of self-controlled feedback on the performance and learning of a movement skill. The task consisted of a blindfolded beanbag toss using the non-preferred arm. Participants were pre-screened according to their physical activity level using the International Physical Activity Questionnaire. An equal number of high activity (HA and low activity (LA participants were assigned to self-control (SC and yoked (YK feedback conditions, creating four groups: Self-Control High Activity (SC-HA; Self-Control Low Activity (SC-LA; Yoked High Activity (YK-HA; and Yoked Low Activity (YK-LA. SC condition participants were provided feedback whenever they requested it, while YK condition participants received feedback according to a schedule created by their SC counterpart. Results indicated that the SC condition was more accurate than the YK condition during acquisition and transfer phases, and the HA condition was more accurate than the LA condition during all phases of the experiment. A post-training questionnaire indicated that participants in the SC condition asked for feedback mostly after what they perceived to be good trials; those in the YK condition indicated that they would have preferred to receive feedback after good trials. This study provided further support for the advantages of self-controlled feedback when learning motor skills, additionally showing benefits for both active and less active individuals. The results suggested that the provision of self-controlled feedback to less active learners may be a potential avenue to teaching motor skills necessary to engage in greater amounts of physical activity.

  4. High salt primes a specific activation state of macrophages, M(Na)

    Science.gov (United States)

    Zhang, Wu-Chang; Zheng, Xiao-Jun; Du, Lin-Juan; Sun, Jian-Yong; Shen, Zhu-Xia; Shi, Chaoji; Sun, Shuyang; Zhang, Zhiyuan; Chen, Xiao-qing; Qin, Mu; Liu, Xu; Tao, Jun; Jia, Lijun; Fan, Heng-yu; Zhou, Bin; Yu, Ying; Ying, Hao; Hui, Lijian; Liu, Xiaolong; Yi, Xianghua; Liu, Xiaojing; Zhang, Lanjing; Duan, Sheng-Zhong

    2015-01-01

    High salt is positively associated with the risk of many diseases. However, little is known about the mechanisms. Here we showed that high salt increased proinflammatory molecules, while decreased anti-inflammatory and proendocytic molecules in both human and mouse macrophages. High salt also potentiated lipopolysaccharide-induced macrophage activation and suppressed interleukin 4-induced macrophage activation. High salt induced the proinflammatory aspects by activating p38/cFos and/or Erk1/2/cFos pathways, while inhibited the anti-inflammatory and proendocytic aspects by Erk1/2/signal transducer and activator of transcription 6 pathway. Consistent with the in vitro results, high-salt diet increased proinflammatory gene expression of mouse alveolar macrophages. In mouse models of acute lung injury, high-salt diet aggravated lipopolysaccharide-induced pulmonary macrophage activation and inflammation in lungs. These results identify a novel macrophage activation state, M(Na), and high salt as a potential environmental risk factor for lung inflammation through the induction of M(Na). PMID:26206316

  5. Wide Frequency Band Active Damping Strategy for DFIG System High Frequency Resonance

    DEFF Research Database (Denmark)

    Song, Yipeng; Blaabjerg, Frede

    2016-01-01

    As a popular renewable power generation solution, the Doubly Fed Induction Generator (DFIG) based wind power system may suffer from High Frequency Resonance (HFR) caused by the impedance interaction between the DFIG system and the parallel compensated weak network. A wide frequency band active...... damping strategy for DFIG system HFR, including a high-pass filter and a virtual resistance, is proposed in this paper. The advantages of this active damping strategy are, 1) no resonance frequency detection unit is required, thus the control complexity can be decreased; 2) no active damping parameters...... adjustment is needed within certain wide frequency band, thus the robustness of the proposed active damping strategy can be improved. The parameter design of the high-pass filter cutoff frequency and the virtual resistance are theoretically analyzed with the purpose of satisfactory active damping. A 7.5 k...

  6. Recurrence or rebound of clinical relapses after discontinuation of natalizumab therapy in highly active MS patients

    DEFF Research Database (Denmark)

    Sorensen, Per Soelberg; Koch-Henriksen, Nils; Petersen, Thor;

    2014-01-01

    A number of studies have reported flare-up of multiple sclerosis (MS) disease activity after cessation of natalizumab, increasing to a level beyond the pre-natalizumab treatment level. Our aim was to describe the development in clinical disease activity following cessation of natalizumab therapy...... in a large unselected cohort of highly active patients. We studied 375 highly active patients who had suffered at least two significant relapses within 1 year or three relapses within 2 years, or had been treated with mitoxantrone for highly active disease. All patients had discontinued therapy...... with natalizumab after at least 24 weeks on therapy, and had been followed 3-12 months (mean 8.9 months) after cessation of natalizumab therapy. The annualised relapse rate before start of natalizumab therapy was 0.94 (95 % confidence interval [CI] 0.88-1.00), 0.47 (95 % CI 0.43-0.52) during natalizumab therapy, 0...

  7. Carbonic anhydrase activity in the red blood cells of sea level and high altitude natives.

    Science.gov (United States)

    Gamboa, J; Caceda, R; Gamboa, A; Monge-C, C

    2000-01-01

    Red blood cell carbonic anhydrase (CA) activity has not been studied in high altitude natives. Because CA is an intraerythocytic enzyme and high altitude natives are polycythemic, it is important to know if the activity of CA per red cell volume is different from that of their sea level counterparts. Blood was collected from healthy subjects living in Lima (150m) and from twelve subjects from Cerro de Pasco (4330m), and hematocrit and carbonic anhydrase activity were measured. As expected, the high altitude natives had significantly higher hematocrits than the sea level controls (p = 0.0002). No difference in the CA activity per milliliter of red cells was found between the two populations. There was no correlation between the hematocrit and CA activity.

  8. Burst activity of the Crab Nebula and its pulsar at high and ultra-high energies

    Science.gov (United States)

    Lidvansky, A. S.

    2016-06-01

    Characteristics of the flares of gamma rays detected from the Crab Nebula by the AGILE and Fermi-LAT satellite instruments are compared with those of a gamma ray burst recorded by several air shower arrays on February 23, 1989 and with one recent observation made by ARGO-YBJ array. It is demonstrated that though pulsar-periodicity and energy spectra of emissions at 100 MeV (satellite gamma ray telescopes) and 100 TeV (EAS arrays) are different, their time structures seem to be similar. Moreover, may be the difference between "flares" and "waves" recently found in the Crab Nebula emission by AGILE team also exists at ultra-high energies.

  9. Preparation, Surface and Pore Structure of High Surface Area Activated Carbon Fibers from Bamboo by Steam Activation

    Directory of Open Access Journals (Sweden)

    Xiaojun Ma

    2014-06-01

    Full Text Available High surface area activated carbon fibers (ACF have been prepared from bamboo by steam activation after liquefaction and curing. The influences of activation temperature on the microstructure, surface area and porosity were investigated. The results showed that ACF from bamboo at 850 °C have the maximum iodine and methylene blue adsorption values. Aside from the graphitic carbon, phenolic and carbonyl groups were the predominant functions on the surface of activated carbon fiber from bamboo. The prepared ACF from bamboo were found to be mainly type I of isotherm, but the mesoporosity presented an increasing trend after 700 °C. The surface area and micropore volume of samples, which were determined by application of the Brunauer-Emmett-Teller (BET and t-plot methods, were as high as 2024 m2/g and 0.569 cm3/g, respectively. It was also found that the higher activation temperature produced the more ordered microcrystalline structure of ACF from bamboo.

  10. Parasympathetic neural activity accounts for the lowering of exercise heart rate at high altitude

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Calbet, J A; Rådegran, G

    2001-01-01

    In chronic hypoxia, both heart rate (HR) and cardiac output (Q) are reduced during exercise. The role of parasympathetic neural activity in lowering HR is unresolved, and its influence on Q and oxygen transport at high altitude has never been studied.......In chronic hypoxia, both heart rate (HR) and cardiac output (Q) are reduced during exercise. The role of parasympathetic neural activity in lowering HR is unresolved, and its influence on Q and oxygen transport at high altitude has never been studied....

  11. Examination of the Effect of High School Students Physical Activity Levels on Their Problem Solving Skills

    OpenAIRE

    Nimet Korkmaz; Serkan Pancar; Tuncay Alparslan; Ayça Ayan

    2017-01-01

    The purpose of this study is to be knowledgeable with demographic characteristics, Body mass index, physical activity levels, problem solving skills and sub-dimensions of the students receiving education at Anatolia High Schools and examine the effect of the physical activity levels of these students on their problem solving skills. The population of the study was included a total of 451 students (female=264; male=187) receiving education at the Anatolia High Schools in the Osmangazi district...

  12. Development of alkali activated cements and concrete mixture design with high volumes of red mud

    OpenAIRE

    KRIVENKO PAVEL; O. Kovalchuk; PASKO ANTON; CROYMANS TOM; HULT MIKAEL; LUTTER GUILLAUME; VANDEVENNE N.; SCHREURS S.; Schroeyers, W.

    2017-01-01

    Dedicated cement compositions were formulated to enable the incorporation of large volume fractions of red mud in alkali activated cements, taking into account the role of the aluminosilicate phase in the processes of hydration and hardening. High volume red mud alkali activated cements were synthesized using a proper combination of red mud, low basic aluminosilicate compounds with a glass phase (blast-furnace slag) and additives selected from high-basic Ca-containing cements with a crystalli...

  13. A high-fat meal does not activate blood coagulation factor VII in minipigs

    DEFF Research Database (Denmark)

    Olsen, A K; Larsen, L F; Bladbjerg, E-M;

    2001-01-01

    , 3.5, 4, 5, and 6 h after the first fat load. Triglycerides, activated FVII (FVIIa), FVII coagulant activity (FVIIc), FVII amidolytic activity (FVIIam) and prothrombin fragment I + 2 (F1 + 2) were analysed in plasma samples. Median plasma triglycerides were significantly raised from 0.67 mmol....../l (baseline) to 2.56 mmol/l 5 h postprandially (P high-fat meal does not seem...

  14. Promoting social skills of mexican high school students through virtual activities in the Moodle platform

    OpenAIRE

    Laura Yolanda RODRÍGUEZ MATAMOROS; Cacheiro González, María Luz; Gil Pascual, Juan Antonio

    2014-01-01

    With the intention of promoting social skills of Mexican high school students based on the graduate profile of this level, virtual activities were implemented in the Moodle platform to 169 students of second year, adopting the proposed Goldstein social skills. In order to establish the impact of these activities to a pretest-postest a one group design was used. The results show that the activities had a positive and significant impact in beginning social skills, advanced social skills, skills...

  15. Microbial activities in a vertical-flow wetland system treating sewage sludge with high organic loads

    Energy Technology Data Exchange (ETDEWEB)

    Wang, R. Y.; Perissol, C.; Baldy, V.; Bonin, G.; Korboulewsky, N.

    2009-07-01

    The rhizosphere is the most active zone in treatment wetlands where take place physicochemical and biological processes between the substrate, plants, microorganisms, and contaminants. Microorganisms play the key role in the mineralisation of organic matter. substrate respiration and phosphatase activities (acid and alkaline) were chosen as indicators of microbial activities, and studied in a vertical-flow wetland system receiving sewage sludge with high organic loads under the Mediterranean climate. (Author)

  16. Effect of high-pressure helium on latex-induced activated chemiluminescence of human blood leucocytes.

    Science.gov (United States)

    Tyurin-Kuz'min, A Yu; Vdovin, A V

    2003-09-01

    High-pressure helium reduces the latex-induced activated chemiluminescence of diluted human blood. This effect is more noticeable, when lucigenin rather than luminol is used as the activator of chemiluminescence. The effect lessens in the presence of Mg2+ but not Ca2+. The data suggest the association of this effect with actin polymerization in leucocytes phagocytosing the latex particles.

  17. A Belief-Behavior Gap? Exploring Religiosity and Sexual Activity among High School Seniors

    Science.gov (United States)

    Leonard, Kathleen Cobb; Scott-Jones, Diane

    2010-01-01

    Religiosity, sexual activity, and contraception were examined via questionnaires and interviews in a diverse sample of 118 high school seniors. The majority reported religion to be important; importance and frequency ratings declined from private (e.g., prayer) to public (e.g., group activities) components of religion. Most were sexually active…

  18. Educational Activities and the Role of the Parent in Homeschool Families with High School Students

    Science.gov (United States)

    Carpenter, Dan; Gann, Courtney

    2016-01-01

    Using a qualitative case study approach, this study looked at the educational activities that constitute a typical day in a homeschool family and the role that the parent has within those activities. Three homeschooling families with high school students in a single community in a southern state in the United States participated in the case study.…

  19. New approach for high-throughput screening of drug activity on Plasmodium liver stages.

    NARCIS (Netherlands)

    Gego, A.; Silvie, O.; Franetich, J.F.; Farhati, K.; Hannoun, L.; Luty, A.J.F.; Sauerwein, R.W.; Boucheix, C.; Rubinstein, E.; Mazier, D.

    2006-01-01

    Plasmodium liver stages represent potential targets for antimalarial prophylactic drugs. Nevertheless, there is a lack of molecules active on these stages. We have now developed a new approach for the high-throughput screening of drug activity on Plasmodium liver stages in vitro, based on an

  20. Contradictions between the Virtual and Physical High School Classroom: A Third-Generation Activity Theory Perspective

    Science.gov (United States)

    Murphy, Elizabeth; Manzanares, Maria A. Rodriguez

    2008-01-01

    This paper uses a third-generation Activity Theory perspective to gain insight into the contradictions between the activity systems of the physical and virtual high school classroom from the perspective of teachers who had transitioned from one system to the other. Data collection relied on semi-structured interviews conducted with e-teachers as…

  1. A High Step-Down Interleaved Buck Converter with Active-Clamp Circuits for Wind Turbines

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2012-12-01

    Full Text Available In this paper, a high step-down interleaved buck coupled-inductor converter (IBCC with active-clamp circuits for wind energy conversion has been studied. In high step-down voltage applications, an IBCC can extend duty ratio and reduce voltage stresses on active switches. In order to reduce switching losses of active switches to improve conversion efficiency, a IBCC with soft-switching techniques is usually required. Compared with passive-clamp circuits, the IBCC with active-clamp circuits have lower switching losses and minimum ringing voltage of the active switches. Thus, the proposed IBCC with active-clamp circuits for wind energy conversion can significantly increase conversion efficiency. Finally, a 240 W prototype of the proposed IBCC with active-clamp circuits was built and implemented. Experimental results have shown that efficiency can reach as high as 91%. The proposed IBCC with active-clamp circuits is presented in high step-down voltage applications to verify the performance and the feasibility for energy conversion of wind turbines.

  2. Enhanced antioxidant and antityrosinase activities of longan fruit pericarp by ultra-high-pressure-assisted extraction.

    Science.gov (United States)

    Prasad, K Nagendra; Yang, Bao; Shi, John; Yu, Chunyan; Zhao, Mouming; Xue, Sophia; Jiang, Yueming

    2010-01-20

    The health benefits of fruits acting against chronic diseases are ascribed to their antioxidant activities which are mainly responsible due to the presence of phenolic compounds. The use of ultra-high-pressure-assisted extraction (UHPE) has shown great advantages for the extraction of these phenolic compounds from longan fruit pericarp (LFP). Studies were carried out to investigate the effects of UHPE at pressures of 200, 300, 400 and 500 MPa on total phenolic contents, extraction yield, antioxidant and antityrosinase activities from LFP. The antioxidant activities of these extracts were analyzed, using various antioxidant models like 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, total antioxidant capacity and superoxide anion radical scavenging activity. Extract from ultra-high-pressure-assisted extraction at 500MPa (UHPE-500) showed the highest antioxidant activities of all the tested models. In addition, it also showed moderate tyrosinase inhibitory activity. Three phenolic acids, namely gallic acid, ellagic acid, and corilagin were identified and quantified by HPLC. Corilagin content was the highest compared to other phenolic acids identified. UHPE-500 obtained the higher phenolic acid contents compared to other high pressure processing and conventional extractions (CE). Compared with CE, UHPE-500 exhibited good extraction effectiveness in terms of higher extraction yields with high phenolic contents and also with higher antioxidant and antityrosinase activities.

  3. New approach for high-throughput screening of drug activity on Plasmodium liver stages.

    NARCIS (Netherlands)

    Gego, A.; Silvie, O.; Franetich, J.F.; Farhati, K.; Hannoun, L.; Luty, A.J.F.; Sauerwein, R.W.; Boucheix, C.; Rubinstein, E.; Mazier, D.

    2006-01-01

    Plasmodium liver stages represent potential targets for antimalarial prophylactic drugs. Nevertheless, there is a lack of molecules active on these stages. We have now developed a new approach for the high-throughput screening of drug activity on Plasmodium liver stages in vitro, based on an infrare

  4. The effects of high-voltage pulse electric discharges on ion adsorption on activated carbons

    Science.gov (United States)

    Gafurov, M. M.; Sveshnikova, D. A.; Larin, S. V.; Rabadanov, K. Sh.; Shabanova, Z. E.; Yusupova, A. A.; Ramazanov, A. Sh.

    2008-07-01

    The effects of high-voltage pulse electric discharges (HPED) on sorption of boron and sulfate ions on activated carbons of different kinds (KM-2, BAU, DAK) were investigated. The effect of HPED activation on the sorption characteristics of the systems was found to be similar to the temperature effect.

  5. Is Childhood Obesity Associated with High-Fat Foods and Low Physical Activity?

    Science.gov (United States)

    Muecke, Lee; And Others

    1992-01-01

    Study investigated whether high-fat food consumption and low physical activity were risk factors for obesity in third graders. Tests revealed a greater prevalence of childhood obesity in 1985 than in 1976-80. Neither intake nor activity level were independent risk factors, but there may be synergistic effects with both present. (SM)

  6. Participation in Daily Activities of Young Adults with High Functioning Autism Spectrum Disorder

    Science.gov (United States)

    McCollum, Mary; LaVesser, Patti; Berg, Christine

    2016-01-01

    Young adults with an autism spectrum disorder (ASD) struggle to assume adult roles. This research assessed the feasibility of using the Adolescent and Young Adult Activity Card Sort (AYA-ACS) with emerging adults with high functioning ASD. Two phases were utilized during this research: (1) comparing the activity participation reported by emerging…

  7. High activity enables life on a high-sugar diet: blood glucose regulation in nectar-feeding bats.

    Science.gov (United States)

    Kelm, Detlev H; Simon, Ralph; Kuhlow, Doreen; Voigt, Christian C; Ristow, Michael

    2011-12-01

    High blood glucose levels caused by excessive sugar consumption are detrimental to mammalian health and life expectancy. Despite consuming vast quantities of sugar-rich floral nectar, nectar-feeding bats are long-lived, provoking the question of how they regulate blood glucose. We investigated blood glucose levels in nectar-feeding bats (Glossophaga soricina) in experiments in which we varied the amount of dietary sugar or flight time. Blood glucose levels increased with the quantity of glucose ingested and exceeded 25 mmol l(-1) blood in resting bats, which is among the highest values ever recorded in mammals fed sugar quantities similar to their natural diet. During normal feeding, blood glucose values decreased with increasing flight time, but only fell to expected values when bats spent 75 per cent of their time airborne. Either nectar-feeding bats have evolved mechanisms to avoid negative health effects of hyperglycaemia, or high activity is key to balancing blood glucose levels during foraging. We suggest that the coevolutionary specialization of bats towards a nectar diet was supported by the high activity and elevated metabolic rates of these bats. High activity may have conferred benefits to the bats in terms of behavioural interactions and foraging success, and is simultaneously likely to have increased their efficiency as plant pollinators.

  8. Facilitation of epileptic activity during sleep is mediated by high amplitude slow waves.

    Science.gov (United States)

    Frauscher, Birgit; von Ellenrieder, Nicolás; Ferrari-Marinho, Taissa; Avoli, Massimo; Dubeau, François; Gotman, Jean

    2015-06-01

    Epileptic discharges in focal epilepsy are frequently activated during non-rapid eye movement sleep. Sleep slow waves are present during this stage and have been shown to include a deactivated ('down', hyperpolarized) and an activated state ('up', depolarized). The 'up' state enhances physiological rhythms, and we hypothesize that sleep slow waves and particularly the 'up' state are the specific components of non-rapid eye movement sleep that mediate the activation of epileptic activity. We investigated eight patients with pharmaco-resistant focal epilepsies who underwent combined scalp-intracerebral electroencephalography for diagnostic evaluation. We analysed 259 frontal electroencephalographic channels, and manually marked 442 epileptic spikes and 8487 high frequency oscillations during high amplitude widespread slow waves, and during matched control segments with low amplitude widespread slow waves, non-widespread slow waves or no slow waves selected during the same sleep stages (total duration of slow wave and control segments: 49 min each). During the slow waves, spikes and high frequency oscillations were more frequent than during control segments (79% of spikes during slow waves and 65% of high frequency oscillations, both P ∼ 0). The spike and high frequency oscillation density also increased for higher amplitude slow waves. We compared the density of spikes and high frequency oscillations between the 'up' and 'down' states. Spike and high frequency oscillation density was highest during the transition from the 'up' to the 'down' state. Interestingly, high frequency oscillations in channels with normal activity expressed a different peak at the transition from the 'down' to the 'up' state. These results show that the apparent activation of epileptic discharges by non-rapid eye movement sleep is not a state-dependent phenomenon but is predominantly associated with specific events, the high amplitude widespread slow waves that are frequent, but not

  9. Phosphorylation of Cdc5 regulates its accumulation

    Directory of Open Access Journals (Sweden)

    Simpson-Lavy Kobi J

    2011-12-01

    Full Text Available Abstract Background Cdc5 (polo kinase/Plk1 is a highly conserved key regulator of the S. cerevisiae cell cycle from S-phase until cytokinesis. However, much of the regulatory mechanisms that govern Cdc5 remain to be determined. Cdc5 is phosphorylated on up to 10 sites during mitosis. In this study, we investigated the function of phosphorylation site T23, the only full consensus Cdk1 (Cdc28 phosphorylation site present. Findings Cdc5T23A introduces a degron that reduces its cellular amount to undetectable levels, which are nevertheless sufficient for normal cell proliferation. The degron acts in cis and is reversed by N-terminal GFP-tagging. Cdk1 kinase activity is required to maintain Cdc5 levels during G2. This, Cdk1 inhibited, Cdc5 degradation is APC/CCdh1 independent and requires new protein synthesis. Cdc5T23E is hyperactive, and reduces the levels of Cdc5 (in trans and drastically reduces Clb2 levels. Conclusions Phosphorylation of Cdc5 by Cdk1 is required to maintain Cdc5 levels during G2. However, phosphorylation of T23 (probably by Cdk1 caps Cdc5 and other CLB2 cluster protein accumulation, preventing potential protein toxicity, which may arise from their overexpression or from APC/CCdh1 inactivation.

  10. Hierarchical Pd-Sn alloy nanosheet dendrites: an economical and highly active catalyst for ethanol electrooxidation.

    Science.gov (United States)

    Ding, Liang-Xin; Wang, An-Liang; Ou, Yan-Nan; Li, Qi; Guo, Rui; Zhao, Wen-Xia; Tong, Ye-Xiang; Li, Gao-Ren

    2013-01-01

    Hierarchical alloy nanosheet dendrites (ANSDs) are highly favorable for superior catalytic performance and efficient utilization of catalyst because of the special characteristics of alloys, nanosheets, and dendritic nanostructures. In this paper, we demonstrate for the first time a facile and efficient electrodeposition approach for the controllable synthesis of Pd-Sn ANSDs with high surface area. These synthesized Pd-Sn ANSDs exhibit high electrocatalytic activity and superior long-term cycle stability toward ethanol oxidation in alkaline media. The enhanced electrocataytic activity of Pd-Sn ANSDs may be attributed to Pd-Sn alloys, nanosheet dendrite induced promotional effect, large number of active sites on dendrite surface, large surface area, and good electrical contact with the base electrode. Because of the simple implement and high flexibility, the proposed approach can be considered as a general and powerful strategy to synthesize the alloy electrocatalysts with high surface areas and open dendritic nanostructures.

  11. Visualization of Active Glucocerebrosidase in Rodent Brain with High Spatial Resolution following In Situ Labeling with Fluorescent Activity Based Probes.

    Directory of Open Access Journals (Sweden)

    Daniela Herrera Moro Chao

    Full Text Available Gaucher disease is characterized by lysosomal accumulation of glucosylceramide due to deficient activity of lysosomal glucocerebrosidase (GBA. In cells, glucosylceramide is also degraded outside lysosomes by the enzyme glucosylceramidase 2 (GBA2 of which inherited deficiency is associated with ataxias. The interest in GBA and glucosylceramide metabolism in the brain has grown following the notion that mutations in the GBA gene impose a risk factor for motor disorders such as α-synucleinopathies. We earlier developed a β-glucopyranosyl-configured cyclophellitol-epoxide type activity based probe (ABP allowing in vivo and in vitro visualization of active molecules of GBA with high spatial resolution. Labeling occurs through covalent linkage of the ABP to the catalytic nucleophile residue in the enzyme pocket. Here, we describe a method to visualize active GBA molecules in rat brain slices using in vivo labeling. Brain areas related to motor control, like the basal ganglia and motor related structures in the brainstem, show a high content of active GBA. We also developed a β-glucopyranosyl cyclophellitol-aziridine ABP allowing in situ labeling of GBA2. Labeled GBA2 in brain areas can be identified and quantified upon gel electrophoresis. The distribution of active GBA2 markedly differs from that of GBA, being highest in the cerebellar cortex. The histological findings with ABP labeling were confirmed by biochemical analysis of isolated brain areas. In conclusion, ABPs offer sensitive tools to visualize active GBA and to study the distribution of GBA2 in the brain and thus may find application to establish the role of these enzymes in neurodegenerative disease conditions such as α-synucleinopathies and cerebellar ataxia.

  12. Activator-inhibitor coupling between Rho signaling and actin assembly make the cell cortex an excitable medium

    Science.gov (United States)

    Bement, William M.; Leda, Marcin; Moe, Alison M.; Kita, Angela M.; Larson, Matthew E.; Golding, Adriana E.; Pfeuti, Courtney; Su, Kuan-Chung; Miller, Ann L.; Goryachev, Andrew B.; von Dassow, George

    2016-01-01

    Animal cell cytokinesis results from patterned activation of the small GTPase Rho, which directs assembly of actomyosin in the equatorial cortex. Cytokinesis is restricted to a portion of the cell cycle following anaphase onset in which the cortex is responsive to signals from the spindle. We show that shortly after anaphase onset oocytes and embryonic cells of frogs and echinoderms exhibit cortical waves of Rho activity and F-actin polymerization. The waves are modulated by cyclin-dependent kinase 1 (Cdk1) activity and require the Rho GEF (guanine nucleotide exchange factor), Ect2. Surprisingly, during wave propagation, while Rho activity elicits F-actin assembly, F-actin subsequently inactivates Rho. Experimental and modeling results show that waves represent excitable dynamics of a reaction diffusion system with Rho as the activator and F-actin the inhibitor. We propose that cortical excitability explains fundamental features of cytokinesis including its cell cycle regulation. PMID:26479320

  13. Inhibitory Effects of Ecklonia cava Extract on High Glucose-Induced Hepatic Stellate Cell Activation

    Directory of Open Access Journals (Sweden)

    Akiko Kojima-Yuasa

    2011-12-01

    Full Text Available Nonalcoholic steatohepatitis (NASH is a disease closely associated with obesity and diabetes. A prevalence of type 2 diabetes and a high body mass index in cryptogenic cirrhosis may imply that obesity leads to cirrhosis. Here, we examined the effects of an extract of Ecklonia cava, a brown algae, on the activation of high glucose-induced hepatic stellate cells (HSCs, key players in hepatic fibrosis. Isolated HSCs were incubated with or without a high glucose concentration. Ecklonia cava extract (ECE was added to the culture simultaneously with the high glucose. Treatment with high glucose stimulated expression of type I collagen and α-smooth muscle actin, which are markers of activation in HSCs, in a dose-dependent manner. The activation of high glucose-treated HSCs was suppressed by the ECE. An increase in the formation of intracellular reactive oxygen species (ROS and a decrease in intracellular glutathione levels were observed soon after treatment with high glucose, and these changes were suppressed by the simultaneous addition of ECE. High glucose levels stimulated the secretion of bioactive transforming growth factor-β (TGF-β from the cells, and the stimulation was also suppressed by treating the HSCs with ECE. These results suggest that the suppression of high glucose-induced HSC activation by ECE is mediated through the inhibition of ROS and/or GSH and the downregulation of TGF-β secretion. ECE is useful for preventing the development of diabetic liver fibrosis.

  14. Active commuting of the inhabitants of Liberec city in low and high walkability areas

    Directory of Open Access Journals (Sweden)

    Lukáš Rubín

    2015-12-01

    Full Text Available Background: Active commuting in terms of everyday transport to school or work can have a significant effect on physical activity. Active commuting can be influenced by the environment, and examples from abroad show that current environmental changes tend mostly to promote passive forms of commuting. A similar situation of decreasing active commuting might be expected in the Czech Republic. However, little information has been published to date about the issue of active commuting among the inhabitants of our country. Objective: The main objective of the present study is to describe the active commuting patterns of the inhabitants of Liberec city in low and high walkability areas. Methods: A total of 23,621 economically active inhabitants or students of Liberec city aged 6-87 years (34.77 ± 14.39 participated in the study. The data about commuting were retrieved from the national Population and Housing Census of 2011. Geographic information systems were used to objectively analyze the built environment and to calculate the walkability index. Results: Active commuting to/from school or work is used by 17.41% of inhabitants. Active commuting is dominated by walking (16.60% as opposed to cycling (0.81%. Inhabitants who lived in high walkability areas were more likely to actively commute than those living in low walkability areas (OR = 1.54; 95% CI [1.41, 1.68]. Conclusions: This study confirmed the findings of international studies about the effect of the built environment on active commuting among Liberec inhabitants. Active commuters are often those living near or in the city center, which is characterized by high walkability. In Liberec city, walking as a means of active commuting significantly prevails over cycling. One of the reasons might be the diverse topography of the city and the insufficiently developed cycling network.

  15. PEEK: An excellent precursor for activated carbon production for high temperature application

    Energy Technology Data Exchange (ETDEWEB)

    Cansado, I.P.P.; Goncalves, F.A.M.M.; Nabais, J.M.V.; Ribeiro Carrott, M.M.L.; Carrott, P.J.M. [Centro de Quimica de Evora and Departamento de Quimica, Universidade de Evora, Colegio Luis Antonio Verney, 7000-671 Evora (Portugal)

    2009-02-15

    A series of activated carbons (AC) with high apparent surface area and very high micropore volumes were prepared from granulated PEEK (poly[oxy-1,4-phenylene-oxy-1,4-phenylene-carbonyl-1,4-phenylene]) by physical activation with CO{sub 2} at different temperatures and different activation times. The carbonisation yields at 873, 1073 and 1173 K were 57, 52 and 51%. As the activation temperature increased, between 873 and 1173 K, the burn-off, the micropore volume and mean pore size increased too. Those prepared at 1173 K, with 74% burn-off, present an extremely high apparent surface area (2874 m{sup 2} g{sup -} {sup 1}) and a very high micropore volume (1.27 cm{sup 3} g{sup -} {sup 1}). The presence of pyrone groups, identified by FTIR, on the AC surface corroborates the prevalence of a basic point of zero charge, always higher than 9.2. The thermal stability was checked by thermogravimetric analysis and as the carbonisation temperature increased the thermal stability of the char increased too. All AC obtained from PEEK by physical activation at 1173 K are thermally resistant, as at 1073 K the loss of the initial mass was less than 15%. The collective results confirm that PEEK is an excellent precursor for preparing AC with a high carbonisation yield, a high micropore volume and apparent surface area and a very high resistance at elevated temperature. (author)

  16. High dopant activation of phosphorus in Ge crystal with high-temperature implantation and two-step microwave annealing

    Science.gov (United States)

    Shih, Tzu-Lang; Su, Yin-Hsien; Lee, Wen-Hsi

    2016-09-01

    In this letter, high-temperature ion implantation and low-temperature microwave annealing were employed to achieve high n-type active concentrations, approaching the solid solubility limit, in germanium. To use the characteristics of microwave annealing more effectively, a two-step microwave annealing process was employed. In the first annealing step, a high-power (1200 W; 425 °C) microwave was used to achieve solid-state epitaxial regrowth and to enhance microwave absorption. In the second annealing step, contrary to the usual process of thermal annealing with higher temperature, a lower-power (900 W; 375 °C) microwave process was used to achieve a low sheet resistance, 78Ω/◻, and a high carrier concentration, 1.025 × 1020 P/cm3, which is close to the solid solubility limit of 2 × 1020 P/cm3.

  17. Wide Frequency Band Active Damping Strategy for DFIG System High Frequency Resonance

    DEFF Research Database (Denmark)

    Song, Yipeng; Blaabjerg, Frede

    2016-01-01

    As a popular renewable power generation solution, the Doubly Fed Induction Generator (DFIG) based wind power system may suffer from High Frequency Resonance (HFR) caused by the impedance interaction between the DFIG system and the parallel compensated weak network. A wide frequency band active...... damping strategy for DFIG system HFR, including a high-pass filter and a virtual resistance, is proposed in this paper. The advantages of this active damping strategy are, 1) no resonance frequency detection unit is required, thus the control complexity can be decreased; 2) no active damping parameters...

  18. High order single step time delay compensation algorithm for structural active control

    Institute of Scientific and Technical Information of China (English)

    王焕定; 耿淑伟; 王伟

    2002-01-01

    The optimal instantaneous high order single step algorithm for active control is first discussed andthen, the n + 1 time step controlling force vector of the instantaneous optimal algorithm is derived from way of ntime state vector. An estimating algorithm, is developed from this to solve the problem of active control withtime delay compensation. The estimating algorithm based on this high order single step β method (HSM) foun-dation, is proven by simulation and experiment analysis, to be a valid solution to problem of active control withtime delay compensation.

  19. High Source Levels and Small Active Space of High-Pitched Song in Bowhead Whales (Balaena mysticetus)

    DEFF Research Database (Denmark)

    Tervo, Outi M.; Christoffersen, Mads F.; Simon, Malene

    2012-01-01

    The low frequency, powerful vocalizations of blue and fin whales may potentially be detected by conspecifics across entire ocean basins. In contrast, humpback and bowhead whales produce equally loud, but more complex broadband vocalizations composed of higher frequencies that suffer from higher...... attenuation. Here we evaluate the active space of high-pitched song notes of bowhead whales (Balaena mysticetus) in Western Greenland using measurements of song source levels and ambient noise. Four independent GPS-synchronized hydrophones were deployed through holes in the ice to localize vocalizing bowhead...... whales, estimate source levels and measure ambient noise. The song had a mean apparent source level of 185 ± 2 dB rms re 1µPa and a high mean centroid frequency of 444 ± 48 Hz. Using measured ambient noise levels in the area and Arctic sound spreading models, the estimated active space of these song...

  20. Fashion Design: Designing a Learner-Active, Multi-Level High School Course

    Science.gov (United States)

    Nelson, Diane

    2009-01-01

    A high school fashion design teacher has much in common with the ringmaster of a three-ring circus. The challenges of teaching a hands-on course are to facilitate the entire class and to meet the needs of individual students. When teaching family and consumer sciences, the goal is to have a learner-active classroom. Revamping the high school's…

  1. Effects of Implementing STEM-I Project-Based Learning Activities for Female High School Students

    Science.gov (United States)

    Lou, Shi-Jer; Tsai, Huei-Yin; Tseng, Kuo-Hung; Shih, Ru-Chu

    2014-01-01

    This study aims to explore the application of STEM-I (STEM-Imagination) project-based learning activities and its effects on the effectiveness, processes, and characteristics of STEM integrative knowledge learning and imagination development for female high school students. A total of 72 female high school students were divided into 18 teams.…

  2. Fashion Design: Designing a Learner-Active, Multi-Level High School Course

    Science.gov (United States)

    Nelson, Diane

    2009-01-01

    A high school fashion design teacher has much in common with the ringmaster of a three-ring circus. The challenges of teaching a hands-on course are to facilitate the entire class and to meet the needs of individual students. When teaching family and consumer sciences, the goal is to have a learner-active classroom. Revamping the high school's…

  3. Effects of Music on Physical Activity Rates of Junior High School Physical Education Students

    Science.gov (United States)

    Brewer, Lindsey; Barney, David C.; Prusak, Keven A.; Pennington, Todd

    2016-01-01

    Music is an everyday occurrence in a person's life. Music is heard in the workplace, in homes, and in the mall. Music can also be heard as a person exercises. Therefore, the purpose of this study was to examine the effects of music on junior high students (n = 305) step counts and time in activity in junior high school physical education classes.…

  4. Investigation of the Relations between Religious Activities and Subjective Well-Being of High School Students

    Science.gov (United States)

    Eryilmaz, Ali

    2015-01-01

    This study aims to investigate the relation between participation in religious activities and the subjective wellbeing of high school students. The study group involves 196 participants, 99 female and 97 male; all of the participants were adolescents attending high school in Eskisehir, Turkey, their ages varying from 14 to 16. The measurement…

  5. Disjunction of conjoined twins: Cdk1, Cdh1 and separation of centrosomes

    Directory of Open Access Journals (Sweden)

    Surana Uttam

    2006-06-01

    Full Text Available Abstract Accurate transmission of chromosomes from parent to progeny cell requires assembly of a bipolar spindle. Centrosomes (spindle pole body in yeast are critical for the biogenesis of this complex mitotic apparatus since they confer bipolarity on the spindle and serve as the site of microtubule polymerization. In each division cycle, the centrosome is duplicated and the sister-centrosomes move away from each other, forming the two poles of the spindle. While the structure and the duplication of centrosomes have been investigated extensively, the understanding of the control of their segregation remains scant. Recent findings are beginning to yield insights into the regulation of centrosome segregation in yeast and its link to the mitotic kinase.

  6. Outdoor Activity and High Altitude Exposure During Pregnancy: A Survey of 459 Pregnancies.

    Science.gov (United States)

    Keyes, Linda E; Hackett, Peter H; Luks, Andrew M

    2016-06-01

    To evaluate whether women engage in outdoor activities and high altitude travel during pregnancy; the health care advice received regarding high altitude during pregnancy; and the association between high altitude exposure and self-reported pregnancy complications. An online survey of women with at least 1 pregnancy distributed on websites and e-mail lists targeting mothers and/or mountain activities. Outcome measures were outdoor activities during pregnancy, high altitude (>2440 m) exposure during pregnancy, and pregnancy and perinatal complications. Hiking, running, and swimming were the most common activities performed during pregnancy. Women traveled to high altitude in over half of the pregnancies (244/459), and most did not receive counseling regarding altitude (355, 77%), although a small proportion (14, 3%) were told not to go above 2440 m. Rates of miscarriage and most other complications were similar between pregnancies with and without travel above 2440 m. Pregnancies with high altitude exposure were more likely to have preterm labor (odds ratio [OR] 2.3; 95% CI 0.97-5.4; P = .05). Babies born to women who went to high altitude during pregnancy were more likely to need oxygen at birth (OR 2.34; 95% CI 1.04-5.26; P < .05) but had similar rates of neonatal intensive care unit admission (P = not significant). Our results suggest pregnant women who are active in outdoor sports and travel to high altitude have a low rate of complications. Given the limitations of our data, further research is necessary on the risks associated with high altitude travel and physical activity and how these apply to the general population. Copyright © 2016 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  7. Application of High-speed Solenoid Valve to the Semi-active Control of Landing Gear

    Institute of Scientific and Technical Information of China (English)

    Liu Hui; Gu Hongbin; Chen Dawei

    2008-01-01

    To select or develop an appropriate actuator is one of the key and difficult issues in the study of semi-active controlled landing gear.Performance of the actuator may directly affect the effectiveness of semi-active control.In this article,parallel high-speed solenoid valves are chosen to be the actuators for the semi-active controlled landing gear and being studied.A nonlinear high-speed solenoid valve model is developed with the consideration of magnctic saturation characteristics and verified by test.According to the design rule of keeping the peak load as small as possible while absorbing the specified shock energy,a fuzzy PD control rule is designed.By the rule,controller parameters can be self-regulated.The simulation results indicate that the semi-active control based on high-speed solenoid valve can effectively improve the control performance and reduce impact load during landing.

  8. Efficacy of High Intensity Exercise on Disease Activity and Cardiovascular Risk in Active Axial Spondyloarthritis: A Randomized Controlled Pilot Study

    OpenAIRE

    Silje Halvorsen Sveaas; Inger Jorid Berg; Sella Aarrestad Provan; Anne Grete Semb; Kåre Birger Hagen; Nina Vøllestad; Camilla Fongen; Inge C Olsen; Annika Michelsen; Thor Ueland; Pål Aukrust; Kvien, Tore K; Hanne Dagfinrud

    2014-01-01

    BACKGROUND: Physical therapy is recommended for the management of axial spondyloarthritis (axSpA) and flexibility exercises have traditionally been the main focus. Cardiovascular (CV) diseases are considered as a major health concern in axSpA and there is strong evidence that endurance and strength exercise protects against CV diseases. Therefore, the aim of this study was to investigate the efficacy of high intensity endurance and strength exercise on disease activity and CV health in patien...

  9. Determination of the Biological Activity and Structure Activity Relationships of Drugs Based on the Highly Cytotoxic Duocarmycins and CC-1065

    OpenAIRE

    2009-01-01

    The natural antibiotics CC‑1065 and the duocarmycins are highly cytotoxic compounds which however are not suitable for cancer therapy due to their general toxicity. We have developed glycosidic prodrugs of seco-analogues of these antibiotics for a selective cancer therapy using conjugates of glycohydrolases and tumour-selective monoclonal antibodies for the liberation of the drugs from the prodrugs predominantly at the tumour site. For the determination of structure activity relationships of ...

  10. Multiscale Aspects of Generation of High-Gamma Activity during Seizures in Human Neocortex123

    Science.gov (United States)

    Marcuccilli, Charles J.; Ben-Mabrouk, Faiza; Lew, Sean M.; Goodman, Robert R.; McKhann, Guy M.; Frim, David M.; Kohrman, Michael H.; Schevon, Catherine A.; van Drongelen, Wim

    2016-01-01

    High-gamma (HG; 80-150 Hz) activity in macroscopic clinical records is considered a marker for critical brain regions involved in seizure initiation; it is correlated with pathological multiunit firing during neocortical seizures in the seizure core, an area identified by correlated multiunit spiking and low frequency seizure activity. However, the effects of the spatiotemporal dynamics of seizure on HG power generation are not well understood. Here, we studied HG generation and propagation, using a three-step, multiscale signal analysis and modeling approach. First, we analyzed concurrent neuronal and microscopic network HG activity in neocortical slices from seven intractable epilepsy patients. We found HG activity in these networks, especially when neurons displayed paroxysmal depolarization shifts and network activity was highly synchronized. Second, we examined HG activity acquired with microelectrode arrays recorded during human seizures (n = 8). We confirmed the presence of synchronized HG power across microelectrode records and the macroscale, both specifically associated with the core region of the seizure. Third, we used volume conduction-based modeling to relate HG activity and network synchrony at different network scales. We showed that local HG oscillations require high levels of synchrony to cross scales, and that this requirement is met at the microscopic scale, but not within macroscopic networks. Instead, we present evidence that HG power at the macroscale may result from harmonics of ongoing seizure activity. Ictal HG power marks the seizure core, but the generating mechanism can differ across spatial scales. PMID:27257623

  11. Daily scheduled high fat meals moderately entrain behavioral anticipatory activity, body temperature, and hypothalamic c-Fos activation.

    Directory of Open Access Journals (Sweden)

    Christian M Gallardo

    Full Text Available When fed in restricted amounts, rodents show robust activity in the hours preceding expected meal delivery. This process, termed food anticipatory activity (FAA, is independent of the light-entrained clock, the suprachiasmatic nucleus, yet beyond this basic observation there is little agreement on the neuronal underpinnings of FAA. One complication in studying FAA using a calorie restriction model is that much of the brain is activated in response to this strong hunger signal. Thus, daily timed access to palatable meals in the presence of continuous access to standard chow has been employed as a model to study FAA in rats. In order to exploit the extensive genetic resources available in the murine system we extended this model to mice, which will anticipate rodent high fat diet but not chocolate or other sweet daily meals (Hsu, Patton, Mistlberger, and Steele; 2010, PLoS ONE e12903. In this study we test additional fatty meals, including peanut butter and cheese, both of which induced modest FAA. Measurement of core body temperature revealed a moderate preprandial increase in temperature in mice fed high fat diet but entrainment due to handling complicated interpretation of these results. Finally, we examined activation patterns of neurons by immunostaining for the immediate early gene c-Fos and observed a modest amount of entrainment of gene expression in the hypothalamus of mice fed a daily fatty palatable meal.

  12. Promoting Physical Activity With Group Pictures. Affiliation-Based Visual Communication for High-Risk Populations.

    Science.gov (United States)

    Reifegerste, Doreen; Rossmann, Constanze

    2017-02-01

    Past research in social and health psychology has shown that affiliation motivation is associated with health behavior, especially for high-risk populations, suggesting that targeting this motivation could be a promising strategy to promote physical activity. However, the effects that affiliation appeals (e.g., pictures depicting companionship during physical activities) and accompanying slogans have on motivating physical activity have been largely unexplored. Hence, our two studies experimentally tested the effects of exposure to affiliation-based pictures for overweight or less active people, as well as the moderating effect of affiliation motivation. The results of these two studies give some indication that group pictures (with or without an accompanying slogan) can be an effective strategy to improve high-risk populations' attitudes, self-efficacy, and intentions to engage in physical activity. Affiliation motivation as a personality trait did not interact with these effects, but was positively associated with attitudes, independent of the group picture effect.

  13. Preparation and hydrogen storage capacity of highly porous activated carbon materials derived from polythiophene

    OpenAIRE

    2011-01-01

    [EN] Highly porous carbons have been successfully synthesized by chemical activation of polythiophene with KOH. The activation process was performed under relatively mild activation conditions, i. e., a KOH/polymer weight ratio of 2 and reaction temperatures in the 600–850 °C range. The porous carbons thus obtained possess very large surface areas, up to 3000 m2/g, and pore volumes of up to 1.75 cm3/g. The pore size distribution of these carbons can be tuned via modification of the activation...

  14. New Active Organic Substance in Oyster Shell Capable of Scavenging Oxygen Free Radicals with High Efficiency

    Institute of Scientific and Technical Information of China (English)

    MA Jian-hua

    2008-01-01

    A light purple organic active substance capable of scavenging hydroxyl radical·OH with a high efficiency was extracted from Oyster shell at an extraction rate of 2.49%.It was found for the first time that this active substance may scavenge ·OH with the efficiency far higher than that of vitamin C.This active substance may scavenge also superoxide radical(O2-·)although the scavenging efficiency is far lower than that of vitamin C.Infrared spectrometry and routine chemical analysis primarily reveal that this active substance belongs to glycoprotein.

  15. Influence of mature men way of life on highly intensive physical activity

    Directory of Open Access Journals (Sweden)

    O.B. Pryshva

    2017-04-01

    Full Text Available Highly intensive physical activity is the most effective for men’s health protection. In modern life conditions its level is insufficient. It requires organism’s appropriate physical activity, which is determined by way of life. Especially important it is before trainings. Purpose: to study special aspects of different intensity’s physical activity; of eating special food and sleeping regime of mature men before their highly intensive physical trainings. Material: in experiment men (n=26, age - 35-53years, who practice healthy life style and independent physical activity of high intensity, participated. We used bio-register Basis B1. Every day we registered: Peak - physical activity of different intensity; duration and quality of sleep; relative weight of consumed food. Besides, we calculated body mass index and physical condition. The study was conducted during 30 days in winter period. The following results were compared: indicators before not planned physical activity and average-monthly indicators. Results: Before arbitrary physical functioning we found in men: confident weakening of average intensity (by 9-11% and low intensity (by 10% physical activity; confident increase of consumed food’s relative weight (by 6.82%, vegetarian food (by 10.64% and raw food (by 7.61%; confident reduction of animal origin food (by 8.7%. No changes were found in duration and quality of sleep before highly intensive physical functioning. Conclusions: specific features of mature men’s way of life before their not planned highly intensive physical functioning are as follows: reduction of general physical activity; increase of consumed food. These factors facilitate energy accumulation in organism for its realization in highly intensive physical functioning the next day.

  16. Spatial patterns of high Aedes aegypti oviposition activity in northwestern Argentina.

    Directory of Open Access Journals (Sweden)

    Elizabet Lilia Estallo

    Full Text Available BACKGROUND: In Argentina, dengue has affected mainly the Northern provinces, including Salta. The objective of this study was to analyze the spatial patterns of high Aedes aegypti oviposition activity in San Ramón de la Nueva Orán, northwestern Argentina. The location of clusters as hot spot areas should help control programs to identify priority areas and allocate their resources more effectively. METHODOLOGY: Oviposition activity was detected in Orán City (Salta province using ovitraps, weekly replaced (October 2005-2007. Spatial autocorrelation was measured with Moran's Index and depicted through cluster maps to identify hot spots. Total egg numbers were spatially interpolated and a classified map with Ae. aegypti high oviposition activity areas was performed. Potential breeding and resting (PBR sites were geo-referenced. A logistic regression analysis of interpolated egg numbers and PBR location was performed to generate a predictive mapping of mosquito oviposition activity. PRINCIPAL FINDINGS: Both cluster maps and predictive map were consistent, identifying in central and southern areas of the city high Ae. aegypti oviposition activity. A logistic regression model was successfully developed to predict Ae. aegypti oviposition activity based on distance to PBR sites, with tire dumps having the strongest association with mosquito oviposition activity. A predictive map reflecting probability of oviposition activity was produced. The predictive map delimitated an area of maximum probability of Ae. aegypti oviposition activity in the south of Orán city where tire dumps predominate. The overall fit of the model was acceptable (ROC=0.77, obtaining 99% of sensitivity and 75.29% of specificity. CONCLUSIONS: Distance to tire dumps is inversely associated with high mosquito activity, allowing us to identify hot spots. These methodologies are useful for prevention, surveillance, and control of tropical vector borne diseases and might assist

  17. Spatial Patterns of High Aedes aegypti Oviposition Activity in Northwestern Argentina

    Science.gov (United States)

    Estallo, Elizabet Lilia; Más, Guillermo; Vergara-Cid, Carolina; Lanfri, Mario Alberto; Ludueña-Almeida, Francisco; Scavuzzo, Carlos Marcelo; Introini, María Virginia; Zaidenberg, Mario; Almirón, Walter Ricardo

    2013-01-01

    Background In Argentina, dengue has affected mainly the Northern provinces, including Salta. The objective of this study was to analyze the spatial patterns of high Aedes aegypti oviposition activity in San Ramón de la Nueva Orán, northwestern Argentina. The location of clusters as hot spot areas should help control programs to identify priority areas and allocate their resources more effectively. Methodology Oviposition activity was detected in Orán City (Salta province) using ovitraps, weekly replaced (October 2005–2007). Spatial autocorrelation was measured with Moran’s Index and depicted through cluster maps to identify hot spots. Total egg numbers were spatially interpolated and a classified map with Ae. aegypti high oviposition activity areas was performed. Potential breeding and resting (PBR) sites were geo-referenced. A logistic regression analysis of interpolated egg numbers and PBR location was performed to generate a predictive mapping of mosquito oviposition activity. Principal Findings Both cluster maps and predictive map were consistent, identifying in central and southern areas of the city high Ae. aegypti oviposition activity. A logistic regression model was successfully developed to predict Ae. aegypti oviposition activity based on distance to PBR sites, with tire dumps having the strongest association with mosquito oviposition activity. A predictive map reflecting probability of oviposition activity was produced. The predictive map delimitated an area of maximum probability of Ae. aegypti oviposition activity in the south of Orán city where tire dumps predominate. The overall fit of the model was acceptable (ROC = 0.77), obtaining 99% of sensitivity and 75.29% of specificity. Conclusions Distance to tire dumps is inversely associated with high mosquito activity, allowing us to identify hot spots. These methodologies are useful for prevention, surveillance, and control of tropical vector borne diseases and might assist National Health

  18. An Embedded System for applying High Performance Computing in Educational Learning Activity

    OpenAIRE

    Irene Erlyn Wina Rachmawan; Nurul Fahmi; Edi Wahyu Widodo; Samsul Huda; M. Unggul Pamenang; M. Choirur Roziqin; Andri Permana W.; Stritusta Sukaridhoto; Dadet Pramadihanto

    2016-01-01

    HPC (High Performance Computing) has become more popular in the last few years. With the benefits on high computational power, HPC has impact on industry, scientific research and educational activities. Implementing HPC as a curriculum in universities could be consuming a lot of resources because well-known HPC system are using Personal Computer or Server. By using PC as the practical moduls it is need great resources and spaces.  This paper presents an innovative high performance computing c...

  19. Research Activity in Computational Physics utilizing High Performance Computing: Co-authorship Network Analysis

    Science.gov (United States)

    Ahn, Sul-Ah; Jung, Youngim

    2016-10-01

    The research activities of the computational physicists utilizing high performance computing are analyzed by bibliometirc approaches. This study aims at providing the computational physicists utilizing high-performance computing and policy planners with useful bibliometric results for an assessment of research activities. In order to achieve this purpose, we carried out a co-authorship network analysis of journal articles to assess the research activities of researchers for high-performance computational physics as a case study. For this study, we used journal articles of the Scopus database from Elsevier covering the time period of 2004-2013. We extracted the author rank in the physics field utilizing high-performance computing by the number of papers published during ten years from 2004. Finally, we drew the co-authorship network for 45 top-authors and their coauthors, and described some features of the co-authorship network in relation to the author rank. Suggestions for further studies are discussed.

  20. Small-molecule activators of insulin-degrading enzyme discovered through high-throughput compound screening.

    Directory of Open Access Journals (Sweden)

    Christelle Cabrol

    Full Text Available BACKGROUND: Hypocatabolism of the amyloid beta-protein (Abeta by insulin-degrading enzyme (IDE is implicated in the pathogenesis of Alzheimer disease (AD, making pharmacological activation of IDE an attractive therapeutic strategy. However, it has not been established whether the proteolytic activity of IDE can be enhanced by drug-like compounds. METHODOLOGY/PRINCIPAL FINDINGS: Based on the finding that ATP and other nucleotide polyphosphates modulate IDE activity at physiological concentrations, we conducted parallel high-throughput screening campaigns in the absence or presence of ATP and identified two compounds--designated Ia1 and Ia2--that significantly stimulate IDE proteolytic activity. Both compounds were found to interfere with the crosslinking of a photoaffinity ATP analogue to IDE, suggesting that they interact with a bona fide ATP-binding domain within IDE. Unexpectedly, we observed highly synergistic activation effects when the activity of Ia1 or Ia2 was tested in the presence of ATP, a finding that has implications for the mechanisms underlying ATP-mediated activation of IDE. Notably, Ia1 and Ia2 activated the degradation of Abeta by approximately 700% and approximately 400%, respectively, albeit only when Abeta was presented in a mixture also containing shorter substrates. CONCLUSIONS/SIGNIFICANCE: This study describes the first examples of synthetic small-molecule activators of IDE, showing that pharmacological activation of this important protease with drug-like compounds is achievable. These novel activators help to establish the putative ATP-binding domain as a key modulator of IDE proteolytic activity and offer new insights into the modulatory action of ATP. Several larger lessons abstracted from this screen will help inform the design of future screening campaigns and facilitate the eventual development of IDE activators with therapeutic utility.

  1. High Performance Liquid Chromatography-mass Spectrometry Analysis of High Antioxidant Australian Fruits with Antiproliferative Activity Against Cancer Cells

    Science.gov (United States)

    Sirdaarta, Joseph; Maen, Anton; Rayan, Paran; Matthews, Ben; Cock, Ian Edwin

    2016-01-01

    Background: High antioxidant capacities have been linked to the treatment and prevention of several cancers. Recent reports have identified several native Australian fruits with high antioxidant capacities. Despite this, several of these species are yet to be tested for anticancer activity. Materials and Methods: Solvent extracts prepared from high antioxidant native Australian fruits were analyzed for antioxidant capacity by the di (phenyl)-(2,4,6-trinitrophenyl) iminoazanium free radical scavenging assay. Antiproliferative activities against CaCo2 and HeLa cancer cells were determined by a multicellular tumor spheroid-based cell proliferation assay. Toxicity was determined by Artemia franciscana bioassay. Results: Methanolic extracts of all plant species displayed high antioxidant contents (equivalent to approximately 7–16 mg of vitamin C per gram of fruit extracted). Most aqueous extracts also contained relatively high antioxidant capacities. In contrast, the ethyl acetate, chloroform, and hexane extracts of most species (except lemon aspen and bush tomato) had lower antioxidant contents (below 1.5 mg of vitamin C equivalents per gram of plant material extracted). The antioxidant contents correlated with the ability of the extracts to inhibit proliferation of CaCo2 and HeLa cancer cell lines. The high antioxidant methanolic extracts of all species were potent inhibitors of cell proliferation. The methanolic lemon aspen extract was particularly effective, with IC50 values of 480 and 769 μg/mL against HeLa and CaCo2 cells, respectively. In contrast, the lower antioxidant ethyl acetate and hexane extracts (except the lemon aspen ethyl acetate extract) generally did not inhibit cancer cell proliferation or inhibited to only a minor degree. Indeed, most of the ethyl acetate and hexane extracts induced potent cell proliferation. The native tamarind ethyl acetate extract displayed low-moderate toxicity in the A. franciscana bioassay (LC50 values below 1000

  2. An exposure:activity profiling method for interpreting high-throughput screening data for estrogenic activity--proof of concept.

    Science.gov (United States)

    Becker, Richard A; Friedman, Katie Paul; Simon, Ted W; Marty, M Sue; Patlewicz, Grace; Rowlands, J Craig

    2015-04-01

    Rapid high throughput in vitro screening (HTS) assays are now available for characterizing dose-responses in assays that have been selected for their sensitivity in detecting estrogen-related endpoints. For example, EPA's ToxCast™ program recently released endocrine assay results for more than 1800 substances and the interagency Tox21 consortium is in the process of releasing data for approximately 10,000 chemicals. But such activity measurements alone fall short for the purposes of priority setting or screening because the relevant exposure context is not considered. Here, we extend the method of exposure:activity profiling by calculating the exposure:activity ratios (EARs) using human exposure estimates and AC50 values for a range of chemicals tested in a suite of seven estrogenic assays in ToxCast™ and Tox21. To provide additional context, relative estrogenic exposure:activity quotients (REEAQ) were derived by comparing chemical-specific EARs to the EAR of the ubiquitous dietary phytoestrogen, genistein (GEN). Although the activity of a substance in HTS-endocrine assays is not a measure of health hazard or risk, understanding how such a dose compares to human exposures provides a valuable additional metric that can be used in decision-making; substances with small EARs and REEAQs would indicate low priority for further endocrine screening or testing.

  3. Goals and intentions mediate efficacy beliefs and declining physical activity in high school girls.

    Science.gov (United States)

    Dishman, Rod K; Saunders, Ruth P; Felton, Gwen; Ward, Dianne S; Dowda, Marsha; Pate, Russ R

    2006-12-01

    According to theory, girls who set goals about increasing their physical activity and who are dissatisfied with their current activity level are likely to form intentions to be active and to carry out those intentions, especially if they have high efficacy and control beliefs about being physically active. We tested those ideas while observing naturally occurring change during high school. A cohort of 431 black and white girls was tested at the end of their 9th- and 12th-grade academic years. Confirmatory factor analysis established the structural invariance of the measures across the 3-year study period. Structural equation modeling and panel analysis were used to determine whether changes in goal setting and satisfaction would mediate relations of self-efficacy and perceived behavioral control with changes in intention and physical activity. Testing occurred between February and May in 1999 and 2004. Data were analyzed in 2006. Goal setting and intention mediated the indirect relation between self-efficacy and change in physical activity. Perceived behavioral control and physical activity change were related directly and also indirectly by a path mediated through satisfaction and intention. Black girls had lower self-efficacy, but changes in other variables were unrelated to race. These observations of longitudinal relations elaborate application of self-efficacy theory and the theory of planned behavior to physical activity by showing that goal setting and satisfaction mediate the relations of self-efficacy and perceived behavioral control with changes in intention and physical activity. The results encourage additional research to identify the sources and development of physical activity goals, and their attainment, among girls, and whether experimental manipulation of goals and intentions can mitigate the decline in girls' physical activity during high school.

  4. High efficiency of CO2-activated graphite felt as electrode for vanadium redox flow battery application

    Science.gov (United States)

    Chang, Yu-Chung; Chen, Jian-Yu; Kabtamu, Daniel Manaye; Lin, Guan-Yi; Hsu, Ning-Yih; Chou, Yi-Sin; Wei, Hwa-Jou; Wang, Chen-Hao

    2017-10-01

    A simple method for preparing CO2-activated graphite felt as an electrode in a vanadium redox flow battery (VRFB) was employed by the direct treatment in a CO2 atmosphere at a high temperature for a short period. The CO2-activated graphite felt demonstrates excellent electrochemical activity and reversibility. The VRFB using the CO2-activated graphite felts in the electrodes has coulombic, voltage, and energy efficiencies of 94.52%, 88.97%, and 84.15%, respectively, which is much higher than VRFBs using the electrodes of untreated graphite felt and N2-activated graphite felt. The efficiency enhancement was attributed to the higher number of oxygen-containing functional groups on the graphite felt that are formed during the CO2-activation, leading to improving the electrochemical behaviour of the resultant VRFB.

  5. High Erk-1 activation and Gadd45a expression as prognostic markers in high risk pediatric haemolymphoproliferative diseases

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    Rondelli Roberto

    2009-03-01

    Full Text Available Abstract Studies on activated cell-signaling pathways responsible for neoplastic transformation are numerous in solid tumors and in adult leukemias. Despite of positive results in the evolution of pediatric hematopoietic neoplasias, there are some high-risk subtypes at worse prognosis. The aim of this study was to asses the expression and activation status of crucial proteins involved in cell-signaling pathways in order to identify molecular alterations responsible for the proliferation and/or escape from apoptosis of leukemic blasts. The quantitative and qualitative expression and activation of Erk-1, c-Jun, Caspase8, and Gadd45a was analyzed, by immunocytochemical (ICC and western blotting methods, in bone marrow blasts of 72 patients affected by acute myeloid leukemia (AML, T-cell acute lymphoblastic leukemia (ALL and stage IV non-Hodgkin Lymphoma (NHL. We found an upregulation of Erk-1, Caspase8, c-Jun, and Gadd45a proteins with a constitutive activation in 95.8%, 91.7%, 86.2%, 83.4% of analyzed specimens, respectively. It is worth noting that all AML patients showed an upregulation of all proteins studied and the high expression of GADD45a was associated to the lowest DFS median (p = 0.04. On univariate analysis, only Erk-1 phosphorylation status was found to be correlated with a significantly shorter 5-years DFS in all disease subgroups (p = 0.033 and the lowest DFS median in ALL/NHL subgroup (p = 0.04. Moreover, the simultaneous activation of multiple kinases, as we found for c-Jun and Erk-1 (r = 0.26; p = 0.025, might synergistically enhance survival and proliferation potential of leukemic cells. These results demonstrate an involvement of these proteins in survival of blast cells and, consequently, on relapse percentages of the different subgroups of patients.

  6. High-Sugar, but Not High-Fat, Food Activates Supraoptic Nucleus Neurons in the Male Rat.

    Science.gov (United States)

    Hume, Catherine; Sabatier, Nancy; Menzies, John

    2017-07-01

    Oxytocin is a potent anorexigen and is believed to have a role in satiety signaling. We developed rat models to study the activity of oxytocin neurons in response to voluntary consumption or oral gavage of foods using c-Fos immunohistochemistry and in vivo electrophysiology. Using c-Fos expression as an indirect marker of neural activation, we showed that the percentage of magnocellular oxytocin neurons expressing c-Fos increased with voluntary consumption of sweetened condensed milk (SCM). To model the effect of food in the stomach, we gavaged anesthetized rats with SCM. The percentage of supraoptic nucleus and paraventricular nucleus magnocellular oxytocin-immunoreactive neurons expressing c-Fos increased with SCM gavage but not with gastric distention. To further examine the activity of the supraoptic nucleus, we made in vivo electrophysiological recordings from SON neurons, where anesthetized rats were gavaged with SCM or single cream. Pharmacologically identified oxytocin neurons responded to SCM gavage with a linear, proportional, and sustained increase in firing rate, but cream gavage resulted in a transient reduction in firing rate. Blood glucose increased after SCM gavage but not cream gavage. Plasma osmolarity and plasma sodium were unchanged throughout. We show that in response to high-sugar, but not high-fat, food in the stomach, there is an increase in the activity of oxytocin neurons. This does not appear to be a consequence of stomach distention or changes in osmotic pressure. Our data suggest that the presence of specific foods with different macronutrient profiles in the stomach differentially regulates the activity of oxytocin neurons. Copyright © 2017 Endocrine Society.

  7. Differential activation of the dorsal striatum by high-calorie visual food stimuli in obese individuals.

    Science.gov (United States)

    Rothemund, Yvonne; Preuschhof, Claudia; Bohner, Georg; Bauknecht, Hans-Christian; Klingebiel, Randolf; Flor, Herta; Klapp, Burghard F

    2007-08-15

    The neural systems regulating food intake in obese individuals remain poorly understood. Previous studies applied positron emission tomography and manipulated hunger and satiety to investigate differences in appetitive processing between obese and normal-weight individuals. However, it is not known whether manipulation of stimulus value may yield different neural activity in obese as compared to control subjects when intrinsic physiological states are kept constant. We used functional magnetic resonance imaging to investigate 13 obese and 13 normal-weight subjects and manipulated food motivation by presenting visual food stimuli differing in their caloric content and energy density. In contrast to controls, obese women selectively activated the dorsal striatum while viewing high-caloric foods. Moreover, in the high-calorie condition body mass index (BMI) predicted activation in the dorsal striatum, anterior insula, claustrum, posterior cingulate, postcentral and lateral orbitofrontal cortex. The results indicate that in obese individuals simple visual stimulation with food stimuli activates regions related to reward anticipation and habit learning (dorsal striatum). Additionally, high-calorie food images yielded BMI-dependent activations in regions associated with taste information processing (anterior insula and lateral orbitofrontal cortex), motivation (orbitofrontal cortex), emotion as well as memory functions (posterior cingulate). Collectively, the results suggest that the observed activation is independent of the physiological states of hunger and satiation, and thus may contribute to pathological overeating and obesity. Some of the observed activations (dorsal striatum, orbitofrontal cortex) are likely to be dopamine-mediated.

  8. Highly Active Carbon Supported Pd-Ag Nanofacets Catalysts for Hydrogen Production from HCOOH.

    Science.gov (United States)

    Wang, Wenhui; He, Ting; Liu, Xuehua; He, Weina; Cong, Hengjiang; Shen, Yangbin; Yan, Liuming; Zhang, Xuetong; Zhang, Jinping; Zhou, Xiaochun

    2016-08-17

    Hydrogen is regarded as a future sustainable and clean energy carrier. Formic acid is a safe and sustainable hydrogen storage medium with many advantages, including high hydrogen content, nontoxicity, and low cost. In this work, a series of highly active catalysts for hydrogen production from formic acid are successfully synthesized by controllably depositing Pd onto Ag nanoplates with different Ag nanofacets, such as Ag{111}, Ag{100}, and the nanofacet on hexagonal close packing Ag crystal (Ag{hcp}). Then, the Pd-Ag nanoplate catalysts are supported on Vulcan XC-72 carbon black to prevent the aggregation of the catalysts. The research reveals that the high activity is attributed to the formation of Pd-Ag alloy nanofacets, such as Pd-Ag{111}, Pd-Ag{100}, and Pd-Ag{hcp}. The activity order of these Pd-decorated Ag nanofacets is Pd-Ag{hcp} > Pd-Ag{111} > Pd-Ag{100}. Particularly, the activity of Pd-Ag{hcp} is up to an extremely high value, i.e., TOF{hcp} = 19 000 ± 1630 h(-1) at 90 °C (lower limit value), which is more than 800 times higher than our previous quasi-spherical Pd-Ag alloy nanocatalyst. The initial activity of Pd-Ag{hcp} even reaches (3.13 ± 0.19) × 10(6) h(-1) at 90 °C. This research not only presents highly active catalysts for hydrogen generation but also shows that the facet on the hcp Ag crystal can act as a potentially highly active catalyst.

  9. High-intensity erotic visual stimuli de-activate the primary visual cortex in women.

    Science.gov (United States)

    Huynh, Hieu K; Beers, Caroline; Willemsen, Antoon; Lont, Erna; Laan, Ellen; Dierckx, Rudi; Jansen, Monique; Sand, Michael; Weijmar Schultz, Willibrord; Holstege, Gert

    2012-06-01

    The primary visual cortex, Brodmann's area (BA 17), plays a vital role in basic survival mechanisms in humans. In most neuro-imaging studies in which the volunteers have to watch pictures or movies, the primary visual cortex is similarly activated independent of the content of the pictures or movies. However, in case the volunteers perform demanding non-visual tasks, the primary visual cortex becomes de-activated, although the amount of incoming visual sensory information is the same. Do low- and high-intensity erotic movies, compared to neutral movies, produce similar de-activation of the primary visual cortex? Brain activation/de-activation was studied by Positron Emission Tomography scanning of the brains of 12 healthy heterosexual premenopausal women, aged 18-47, who watched neutral, low- and high-intensity erotic film segments. We measured differences in regional cerebral blood flow (rCBF) in the primary visual cortex during watching neutral, low-intensity erotic, and high-intensity erotic film segments. Watching high-intensity erotic, but not low-intensity erotic movies, compared to neutral movies resulted in strong de-activation of the primary (BA 17) and adjoining parts of the secondary visual cortex. The strong de-activation during watching high-intensity erotic film might represent compensation for the increased blood supply in the brain regions involved in sexual arousal, also because high-intensity erotic movies do not require precise scanning of the visual field, because the impact is clear to the observer. © 2012 International Society for Sexual Medicine.

  10. Muscle activation of paraspinal muscles in different types of high heels during standing.

    Science.gov (United States)

    Han, Dongwook

    2015-01-01

    [Purpose] This study researched the effects of different types of high heels on the muscles surrounding the cervical spine, the thoracic spine, and the lumbar spine by analyzing muscle activation of the paraspinal muscles during standing while wearing high heels. The high heels were all of the same height: 8 cm. [Subjects and Methods] The 28 subjects in this experiment were females in their 20s with a foot size of 225-230 mm and a normal gait pattern. To measure the muscle activation of the paraspinal muscles, EMG electrodes were attached on the paraspinal muscles around C6, T7, and L5. The muscle activation during standing while wearing 8-cm-high wedge heels, setback heels, and French heels was then measured. The measurements were performed 3 times each, and the mean value was used for analysis. [Results] The levels of muscle activation of the paraspinal muscles induced by standing on wedge heels, setback heels, and French heels in the cervical and lumbar areas were significantly higher than those induced by standing on bare feet. But there was no significant difference according to the heel types. [Conclusion] The height of the heels presented a greater variable than the width of the heels on the muscle activation of paraspinal muscles. Therefore, wearing high heels is not recommended for those who have pain or functional problems in the cervical and/or lumbar spine.

  11. Caries-free subjects have high levels of urease and arginine deiminase activity

    Directory of Open Access Journals (Sweden)

    Evelyn REYES

    2014-06-01

    Full Text Available Objectives: This study investigated the relationship between urease and arginine deiminase system (ADS activities and dental caries through a cross-sectional study. Material and Methods: Urease and ADS activities were measured in saliva and plaque samples from 10 caries-free subjects and 13 caries-active. Urease activity was obtained from the ammonia produced by incubation of plaque and saliva samples in urea. ADS activity was obtained from the ammonia generated by the arginine-HCl and Tris-maleate buffer. Specific activity was defined as micromoles of ammonia per minute per milligram of protein. Shapiro-Wilk statistical test was used to analyze the distribution of the data, and Mann-Whitney test was used to determine the significance of the data. Results: The specific urease activity in saliva and plaque was significantly higher in individuals with low DMFT scores. ADS activity in saliva (6.050 vs 1.350, p=0.0154 and plaque (8.830 vs 1.210, p=0.025 was also higher in individuals with low DMFT scores. Conclusions: Caries-free subjects had a higher ammonia generation activity by urease and arginine deiminase system for both saliva and plaque samples than low caries-active subjects. High levels of alkali production in oral environment were related to caries-free subjects.

  12. Peak activation of lower limb musculature during high flexion kneeling and transitional movements.

    Science.gov (United States)

    Kingston, David C; Tennant, Liana M; Chong, Helen C; Acker, Stacey M

    2016-09-01

    Few studies have measured lower limb muscle activation during high knee flexion or investigated the effects of occupational safety footwear. Therefore, our understanding of injury and disease mechanisms, such as knee osteoarthritis, is limited for these high-risk postures. Peak activation was assessed in eight bilateral lower limb muscles for twelve male participants, while shod or barefoot. Transitions between standing and kneeling had peak quadriceps and tibialis anterior (TA) activations above 50% MVC. Static kneeling and simulated tasks performed when kneeling had peak TA activity above 15% MVC but below 10% MVC for remaining muscles. In three cases, peak muscle activity was significantly higher (mean 8.9% MVC) when shod. However, net compressive knee joint forces may not be significantly increased when shod. EMG should be used as a modelling input when estimating joint contact forces for these postures, considering the activation levels in the hamstrings and quadriceps muscles during transitions. Practitioner Summary: Kneeling transitional movements are used in activities of daily living and work but are linked to increased knee osteoarthritis risk. We found peak EMG activity of some lower limb muscles to be over 70% MVC during transitions and minimal influence of wearing safety footwear.

  13. Antagonistic interplay between necdin and Bmi1 controls proliferation of neural precursor cells in the embryonic mouse neocortex.

    Science.gov (United States)

    Minamide, Ryohei; Fujiwara, Kazushiro; Hasegawa, Koichi; Yoshikawa, Kazuaki

    2014-01-01

    Neural precursor cells (NPCs) in the neocortex exhibit a high proliferation capacity during early embryonic development and give rise to cortical projection neurons after maturation. Necdin, a mammal-specific MAGE (melanoma antigen) family protein that possesses anti-mitotic and pro-survival activities, is expressed abundantly in postmitotic neurons and moderately in tissue-specific stem cells or progenitors. Necdin interacts with E2F transcription factors and suppresses E2F1-dependent transcriptional activation of the cyclin-dependent kinase Cdk1 gene. Here we show that necdin serves as a suppressor of NPC proliferation in the embryonic neocortex. Necdin is moderately expressed in the ventricular zone of mouse embryonic neocortex, in which proliferative cell populations are significantly increased in necdin-null mice. In the neocortex of necdin-null embryos, expression of Cdk1 and Sox2, a stem cell marker, is significantly increased, whereas expression of p16, a cyclin-dependent kinase inhibitor, is markedly diminished. Cdk1 and p16 expression levels are also significantly increased and decreased, respectively, in primary NPCs prepared from necdin-null embryos. Intriguingly, necdin interacts directly with Bmi1, a Polycomb group protein that suppresses p16 expression and promotes NPC proliferation. In HEK293A cells transfected with luciferase reporter constructs, necdin relieves Bmi1-dependent repression of p16 promoter activity, whereas Bmi1 counteracts necdin-mediated repression of E2F1-dependent Cdk1 promoter activity. In lentivirus-infected primary NPCs, necdin overexpression increases p16 expression, suppresses Cdk1 expression, and inhibits NPC proliferation, whereas Bmi1 overexpression suppresses p16 expression, increases Cdk1 expression, and promotes NPC proliferation. Our data suggest that embryonic NPC proliferation in the neocortex is regulated by the antagonistic interplay between necdin and Bmi1.

  14. High source levels and small active space of high-pitched song in bowhead whales (Balaena mysticetus.

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    Outi M Tervo

    Full Text Available The low-frequency, powerful vocalizations of blue and fin whales may potentially be detected by conspecifics across entire ocean basins. In contrast, humpback and bowhead whales produce equally powerful, but more complex broadband vocalizations composed of higher frequencies that suffer from higher attenuation. Here we evaluate the active space of high frequency song notes of bowhead whales (Balaena mysticetus in Western Greenland using measurements of song source levels and ambient noise. Four independent, GPS-synchronized hydrophones were deployed through holes in the ice to localize vocalizing bowhead whales, estimate source levels and measure ambient noise. The song had a mean apparent source level of 185±2 dB rms re 1 µPa @ 1 m and a high mean centroid frequency of 444±48 Hz. Using measured ambient noise levels in the area and Arctic sound spreading models, the estimated active space of these song notes is between 40 and 130 km, an order of magnitude smaller than the estimated active space of low frequency blue and fin whale songs produced at similar source levels and for similar noise conditions. We propose that bowhead whales spatially compensate for their smaller communication range through mating aggregations that co-evolved with broadband song to form a complex and dynamic acoustically mediated sexual display.

  15. High frequency oscillations mirror disease activity in patients with focal cortical dysplasia.

    Science.gov (United States)

    Kerber, Karolin; LeVan, Pierre; Dümpelmann, Matthias; Fauser, Susanne; Korinthenberg, Rudolf; Schulze-Bonhage, Andreas; Jacobs, Julia

    2013-08-01

    The study analyzes the occurrence of high frequency oscillations in different types of focal cortical dysplasia in 22 patients with refractory epilepsy. High frequency oscillations are biomarkers for epileptic tissue, but it is unknown whether they can reflect increasingly dysplastic tissue changes as well as epileptic disease activity. High frequency oscillations (80-450 Hz) were visually marked by two independent reviewers in all channels of intracranial implanted grid, strips, and depth electrodes in patients with focal cortical dysplasia and refractory epilepsy. Rates of high frequency oscillations in patients with pathologically confirmed focal cortical dysplasia of Palmini type 1a and b were compared with those in type 2a and b. Patients with focal cortical dysplasia type 2 had significantly more seizures than those with type 1 (p high frequency oscillations were significantly higher in patients with focal cortical dysplasia type 2 versus type 1 (p high frequency oscillations were significantly higher in presumed epileptogenic areas than outside (p high frequency oscillations mirrors the higher epileptogenicity of focal cortical dysplasia type 2 lesions compared to type 1 lesions. Therefore, rates of high frequency oscillations can reflect disease activity of a lesion. This has implications for the use of high frequency oscillations as biomarkers for epileptogenic areas, because a detailed analysis of their rates may be necessary to use high frequency oscillations as a predictive tool in epilepsy surgery. Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.

  16. Efficacy of high intensity exercise on disease activity and cardiovascular risk in active axial spondyloarthritis: a randomized controlled pilot study.

    Directory of Open Access Journals (Sweden)

    Silje Halvorsen Sveaas

    Full Text Available BACKGROUND: Physical therapy is recommended for the management of axial spondyloarthritis (axSpA and flexibility exercises have traditionally been the main focus. Cardiovascular (CV diseases are considered as a major health concern in axSpA and there is strong evidence that endurance and strength exercise protects against CV diseases. Therefore, the aim of this study was to investigate the efficacy of high intensity endurance and strength exercise on disease activity and CV health in patients with active axSpA. METHODS: In a single blinded randomized controlled pilot study the exercise group (EG performed 12 weeks of endurance and strength exercise while the control group (CG received treatment as usual. The primary outcome was the Ankylosing Spondylitis (AS Disease Activity Score (ASDAS. Secondary outcomes included patient reported disease activity (Bath AS Disease Activity Index [BASDAI], physical function (Bath AS Functional Index [BASFI], and CV risk factors measured by arterial stiffness (Augmentation Index [Alx] and Pulse Wave Velocity [PWV], cardiorespiratory fitness (VO2 peak and body composition. ANCOVA on the post intervention values with baseline values as covariates was used to assess group differences, and Mann Whitney U-test was used for outcomes with skewed residuals. RESULTS: Twenty-eight patients were included and 24 (EG, n = 10, CG, n = 14 completed the study. A mean treatment effect of -0.7 (95%CI: -1.4, 0.1 was seen in ASDAS score. Treatment effects were also observed in secondary outcomes (mean group difference [95%CI]: BASDAI: -2.0 (-3.6, -0.4, BASFI: -1.4 (-2.6, -0.3, arterial stiffness (estimated median group differences [95% CI]: AIx (%: -5.3 (-11.0, -0.5, and for PVW (m/s: -0.3 (-0.7, 0.0, VO2 peak (ml/kg/min (mean group difference [95%CI]: 3.7 (2.1, 5.2 and trunk fat (%: -1.8 (-3.0, -0.6. No adverse events occurred. CONCLUSION: High intensity exercise improved disease activity and reduced CV risk factors in

  17. Efficacy of high intensity exercise on disease activity and cardiovascular risk in active axial spondyloarthritis: a randomized controlled pilot study.

    Science.gov (United States)

    Sveaas, Silje Halvorsen; Berg, Inger Jorid; Provan, Sella Aarrestad; Semb, Anne Grete; Hagen, Kåre Birger; Vøllestad, Nina; Fongen, Camilla; Olsen, Inge C; Michelsen, Annika; Ueland, Thor; Aukrust, Pål; Kvien, Tore K; Dagfinrud, Hanne

    2014-01-01

    Physical therapy is recommended for the management of axial spondyloarthritis (axSpA) and flexibility exercises have traditionally been the main focus. Cardiovascular (CV) diseases are considered as a major health concern in axSpA and there is strong evidence that endurance and strength exercise protects against CV diseases. Therefore, the aim of this study was to investigate the efficacy of high intensity endurance and strength exercise on disease activity and CV health in patients with active axSpA. In a single blinded randomized controlled pilot study the exercise group (EG) performed 12 weeks of endurance and strength exercise while the control group (CG) received treatment as usual. The primary outcome was the Ankylosing Spondylitis (AS) Disease Activity Score (ASDAS). Secondary outcomes included patient reported disease activity (Bath AS Disease Activity Index [BASDAI]), physical function (Bath AS Functional Index [BASFI]), and CV risk factors measured by arterial stiffness (Augmentation Index [Alx]) and Pulse Wave Velocity [PWV]), cardiorespiratory fitness (VO2 peak) and body composition. ANCOVA on the post intervention values with baseline values as covariates was used to assess group differences, and Mann Whitney U-test was used for outcomes with skewed residuals. Twenty-eight patients were included and 24 (EG, n = 10, CG, n = 14) completed the study. A mean treatment effect of -0.7 (95%CI: -1.4, 0.1) was seen in ASDAS score. Treatment effects were also observed in secondary outcomes (mean group difference [95%CI]): BASDAI: -2.0 (-3.6, -0.4), BASFI: -1.4 (-2.6, -0.3), arterial stiffness (estimated median group differences [95% CI]): AIx (%): -5.3 (-11.0, -0.5), and for PVW (m/s): -0.3 (-0.7, 0.0), VO2 peak (ml/kg/min) (mean group difference [95%CI]: 3.7 (2.1, 5.2) and trunk fat (%): -1.8 (-3.0, -0.6). No adverse events occurred. High intensity exercise improved disease activity and reduced CV risk factors in patients with active axSpA. These

  18. DID SPECULATIVE ACTIVITIES CONTRIBUTE TO HIGH CRUDE OIL PRICES DURING 1993 TO 2008?

    Institute of Scientific and Technical Information of China (English)

    Xun ZHANG; Kin Keung LAI; Shouyang WANG

    2009-01-01

    By applying two nonlinear Granger causality testing methods and rolling window strategy to explore the relationship between speculative activities and crude oil prices, the unidirectional Granger causality from speculative activities to returns of crude oil prices during the high price phase is discovered. It is proved that speculative activities did contribute to high crude oil prices after the Asian financial crisis and OPEC's output cut in 1998. The unidirectional Granger causality from returns of crude oil prices to speculative activities is significant in general. But after 2000, with the sharp rise in crude oil prices, this unidirectional Granger causality became a complex nonlinear relationship, which cannot be detected by any linear Granger causality test.

  19. Inactive experiments for advanced separation processes prior to high activity trials in ATALANTE

    Energy Technology Data Exchange (ETDEWEB)

    Duhamet, Jean; Lanoe, Jean-Yves; Rivalier, Patrick; Borda, Gilles [Commissariat a l' Energie Atomique (CEA), CEA/DEN/VRH/DTEC/SGCS, Centre de Marcoule - BP 17171, 302007 Bagnols-sur-Ceze cedex (France)

    2008-07-01

    Many trials have been performed in ATALANTE's shielded cells to demonstrate the technical feasibility of processes involving minor actinide separation. They required developments of new extractors as well as a step by step procedure have been used to lower the risks of malfunction during high active operation. The design of the extractors developed by Cea has included shielded cells restrictions, miniaturization to lower the quantity of high active material and wastes and the care for being representative of industrial equipment. After individual shake down inactive tests, with actual phases, each process experiment scheduled in ATALANTE has been tested at G1 Facility in Marcoule. The objective was to reproduce as much as possible all the equipment chosen for active tests. This procedure has demonstrated its efficiency to detect many problems that would have heavy impact if they have been discovered during active trials. It was also used for operators'training. (authors)

  20. High inorganic triphosphatase activities in bacteria and mammalian cells: identification of the enzymes involved.

    Directory of Open Access Journals (Sweden)

    Gregory Kohn

    Full Text Available BACKGROUND: We recently characterized a specific inorganic triphosphatase (PPPase from Nitrosomonas europaea. This enzyme belongs to the CYTH superfamily of proteins. Many bacterial members of this family are annotated as predicted adenylate cyclases, because one of the founding members is CyaB adenylate cyclase from A. hydrophila. The aim of the present study is to determine whether other members of the CYTH protein family also have a PPPase activity, if there are PPPase activities in animal tissues and what enzymes are responsible for these activities. METHODOLOGY/PRINCIPAL FINDINGS: Recombinant enzymes were expressed and purified as GST- or His-tagged fusion proteins and the enzyme activities were determined by measuring the release of inorganic phosphate. We show that the hitherto uncharacterized E. coli CYTH protein ygiF is a specific PPPase, but it contributes only marginally to the total PPPase activity in this organism, where the main enzyme responsible for hydrolysis of inorganic triphosphate (PPP(i is inorganic pyrophosphatase. We further show that CyaB hydrolyzes PPP(i but this activity is low compared to its adenylate cyclase activity. Finally we demonstrate a high PPPase activity in mammalian and quail tissue, particularly in the brain. We show that this activity is mainly due to Prune, an exopolyphosphatase overexpressed in metastatic tumors where it promotes cell motility. CONCLUSIONS AND GENERAL SIGNIFICANCE: We show for the first time that PPPase activities are widespread in bacteria and animals. We identified the enzymes responsible for these activities but we were unable to detect significant amounts of PPP(i in E. coli or brain extracts using ion chromatography and capillary electrophoresis. The role of these enzymes may be to hydrolyze PPP(i, which could be cytotoxic because of its high affinity for Ca(2+, thereby interfering with Ca(2+ signaling.

  1. Enabling High Energy Density Li-Ion Batteries through Li{sub 2}O Activation.

    Energy Technology Data Exchange (ETDEWEB)

    Abouimrane, Ali; Cui, Yanjie; Chen, Zonghai; Belharouak, Ilias; Yahia, Hamdi B.; Wu, Huiming; Assary, Rajeev; Curtiss, Larry A.; Amine, Khalil

    2016-09-01

    Lithium oxide (Li2O) is activated in the presence of a layered composite cathode material (HEM) significantly increasing the energy density of lithium-ion batteries. The degree of activation depends on the current rate, electrolyte salt, and anode type. In full-cell tests, the Li2O was used as a lithium source to counter the first-cycle irreversibility of high-capacity composite alloy anodes. When Li2O is mixed with HEM to serve as a cathode, the electrochemical performance was improved in a full cell having an SiO-SnCoC composite as an anode. The mechanism behind the Li2O activation could also explain the first charge plateau and the abnormal high capacity associated with these high energy cathode materials.

  2. Ten-year results of physical activity after high tibial osteotomy in patients with knee osteoarthritis.

    Science.gov (United States)

    W-Dahl, Annette; Toksvig-Larsen, Sören; Lindstrand, Anders

    2017-03-01

    The purpose was to describe physical activity with respect to leisure and working activity in patients operated on by high tibial osteotomy using the hemicallotasis technique for knee osteoarthritis (OA), preoperatively and 10 years postoperatively. Seventy-nine patients, median age 55 (range 35-66), operated on by high tibial osteotomy using the hemicallotasis technique for knee OA 2001-2003 were included. Questionnaires for evaluation of physical and working activity, satisfaction as well as the Knee injury and Osteoarthritis Outcome Score (KOOS) were filled in preoperatively and 2 and 10 years postoperatively. Conversion to knee arthroplasty was obtained through the Swedish Knee Arthroplasty Register. Changes between two postoperative measurements were assessed by Wilcoxon's rank test. Twenty-five patients were converted to a total knee arthroplasty, and nine patients were lost to follow-up during the 10 years, resulted in 45 patients available for follow-up. Preoperatively, 33/45 patients were physically active mainly in heavy yard/household work, and 43/45 patients were working active. Ten years after the HCO, 23/45 patients were still active with golf, dancing, hiking, etc., and 23/45 were retired. At 10 years postoperatively compared to 2 years postoperatively, the patients experienced more problems with pain (89 compared to 69, p = <0.0001). Of 45 patients, 36 were satisfied with the high tibial osteotomy surgery in general 10 years postoperatively, while 13/45 were satisfied with their sport and recreational function. The 10-year results indicate that high tibial osteotomy using the hemicallotasis technique for knee OA is an option for selected patients that improves the level of physical activity, with mild deterioration over time, and gives the majority of the patients the possibility to be working active until retirement. Level IV.

  3. Autophagic flux is highly active in early mitosis and differentially regulated throughout the cell cycle

    OpenAIRE

    Li, Zhiyuan; Ji, Xinmiao; Wang, Dongmei; Liu, Juanjuan; Zhang, Xin

    2016-01-01

    Mitosis is a fast process that involves dramatic cellular remodeling and has a high energy demand. Whether autophagy is active or inactive during the early stages of mitosis in a naturally dividing cell is still debated. Here we aimed to use multiple assays to resolve this apparent discrepancy. Although the LC3 puncta number was reduced in mitosis, the four different cell lines we tested all have active autophagic flux in both interphase and mitosis. In addition, the autophagic flux was highl...

  4. Highly oxygenated triterpenoids from the roots of Schisandra chinensis and their anti-inflammatory activities.

    Science.gov (United States)

    Song, Qiu-Yan; Gao, Kun; Nan, Zhi-Biao

    2016-01-01

    A new highly oxygenated triterpenoid, schinchinenlactone D (1), and three known compounds (2-4) were isolated from the roots of Schisandra chinensis. Their structures were determined by combining the spectroscopic analysis with the theoretical computations. The anti-inflammatory activities of compounds 1-4 were evaluated, and compound 3 exhibits the most significant activity in the inhibition of NO production with an IC50 value of 10.6 μM.

  5. Measurements and simulation of induced activity at the CERN-EU high- energy reference field facility

    CERN Document Server

    Brugger, M; Mitaroff, W A; Roesler, S

    2003-01-01

    Samples of aluminum, copper, stainless steel, iron, boron nitride, carbon composite and water were irradiated by the stray radiation field produced by interactions of high-energy hadrons in a copper target. The specific activity induced in the samples was measured by gamma spectrometry. In addition, the isotope production in the samples was calculated with detailed Monte-Carlo simulations using the FLUKA code. Results of the simulation are in reasonable agreement with the measured activities. 7 Refs.

  6. High-throughput measurement of the Ca2+-dependent ATPase activity in COS microsomes.

    Science.gov (United States)

    Vandecaetsbeek, Ilse; Holemans, Tine; Wuytack, Frank; Vangheluwe, Peter

    2014-08-01

    We provide a detailed procedure to determine the Ca(2+)-dependent ATPase activity in COS or HEK293 cells overexpressing a Ca(2+) pump. The ATPase activity is determined by the Baginsky method, which allows measurement of the steady-state production of inorganic phosphate (Pi). We have adapted this widely applied method into a sensitive, fast, and semi-high-throughput protocol suitable for use in a 96-well plate format.

  7. Ascaroside activity in Caenorhabditis elegans is highly dependent on chemical structure

    OpenAIRE

    Hollister, Kyle A.; Conner, Elizabeth S.; Zhang, Xinxing; Spell, Mark; Bernard, Gary M.; Patel, Pratik; de Carvalho, Ana Carolina G.V.; Butcher, Rebecca A.; Ragains, Justin R.

    2013-01-01

    The nematode Caenorhabditis elegans secretes ascarosides, structurally diverse derivatives of the 3,6-dideoxysugar ascarylose, and uses them in chemical communication. At high population densities, specific ascarosides, which are together known as the dauer pheromone, trigger entry into the stress-resistant dauer larval stage. In order to study the structure-activity relationships for the ascarosides, we synthesized a panel of ascarosides and tested them for dauer-inducing activity. This pane...

  8. Highly dispersive nano-TiO{sub 2} in situ growing on functional graphene with high photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Gonggang; Wang, Ruimeng; Liu, Hui, E-mail: liuhui@csu.edu.cn; Han, Kai; Cui, Huanqing; Ye, Hongqi [Central South University, Department of Chemistry and Chemical Engineering (China)

    2016-01-15

    We present a novel approach to prepare highly dispersive nano-TiO{sub 2} by in situ growth on functional graphene (FG) via impregnation-hydrothermal method. The functional graphene was obtained by means of triethanolamine to modify graphene oxide. The characterization results collected by Fourier-transform infrared spectra, transmission electron microscope, X-ray diffraction, and X-ray photoelectron spectroscopy showed that nano-TiO{sub 2} particles with anatase phase and a narrow size distribution (the average particle size is 5 nm) were dispersed on the surface of FG uniformly. Then, the photocatalytic activity of as-prepared catalyst under UV light was evaluated, and the results showed that it possessed better photocatalytic activity than pure TiO{sub 2} and TiO{sub 2} on GO prepared by similar method. In addition, the as-prepared photocatalyst revealed considerable photocatalytic ability under visible light.

  9. Activation Layer Stabilization of High Polarization Photocathodes in Sub-Optimal RF Gun Environments

    Energy Technology Data Exchange (ETDEWEB)

    Gregory A. Mulhollan

    2010-11-16

    Specific activation recipes for bulk, 100 nm thick MBE grown and high polarization III-V photocathode material have been developed which mitigate the effects of exposure to background gasses. Lifetime data using four representative gasses were acquired for bulk GaAs, 100 nm unstrained GaAs and strained superlattice GaAs/GaAsP, all activated both with Cs and then Cs and Li (bi-alkali). Each photoemitter showed marked resilience improvement when activated using the bi-alkali recipe compared to the standard single alkali recipe. A dual alkali activation system at SLAC was constructed, baked and commissioned with the purpose of performing spin-polarization measurements on electrons emitted from the bi-alkali activated surfaces. An end station at SSRL was configured with the required sources for energy resolved photoemission measurements on the bi-alkali activated and CO2 dosed surfaces. The bi-alkali recipes were successfully implemented at SLAC/SSRL. Measurements at SLAC of the photoelectron spin-polarization from the modified activation surface showed no sign of a change in value compared to the standard activated material, i.e., no ill effects. Analysis of photoemission data indicates that the addition of Li to the activation layer results in a multi-layer structure. The presence of Li in the activation layer also acts as an inhibitor to CO2 absorption, hence better lifetimes in worse vacuum were achieved. The bi-alkali activation has been tested on O2 activated GaAs for comparison with NF3 activated surfaces. Comparable resilience to CO2 exposure was achieved for the O2 activated surface. An RF PECVD amorphous silicon growth system was modified to allow high temperature heat cleaning of GaAs substrates prior to film deposition. Growth versus thickness data were collected. Very thin amorphous silicon germanium layers were optimized to exhibit good behavior as an electron emitter. Growth of the amorphous silicon germanium films on the above substrates was fine tuned

  10. Blueberry polyphenol oxidase: Characterization and the kinetics of thermal and high pressure activation and inactivation.

    Science.gov (United States)

    Terefe, Netsanet Shiferaw; Delon, Antoine; Buckow, Roman; Versteeg, Cornelis

    2015-12-01

    Partially purified blueberry polyphenol oxidase (PPO) in Mcllvaine buffer (pH=3.6, typical pH of blueberry juice) was subjected to processing at isothermal-isobaric conditions at temperatures from 30 to 80 °C and pressure from 0.1 to 700 MPa. High pressure processing at 30-50 °C at all pressures studied caused irreversible PPO activity increase with a maximum of 6.1 fold increase at 500 MPa and 30 °C. Treatments at mild pressure-mild temperature conditions (0.1-400 MPa, 60 °C) also caused up to 3 fold PPO activity increase. Initial activity increase followed by a decrease occurred at relatively high pressure-mild temperature (400-600 MPa, 60 °C) and mild pressure-high temperature (0.1-400 MPa, 70-80 °C) combinations. At temperatures higher than 76 °C, monotonic decrease in PPO activity occurred at 0.1 MPa and pressures higher than 500 MPa. The activation/inactivation kinetics of the enzyme was successfully modelled assuming consecutive reactions in series with activation followed by inactivation.

  11. Promotion of Physical Activity Among High-School Girls: A Randomized Controlled Trial

    Science.gov (United States)

    Pate, Russell R.; Ward, Dianne S.; Saunders, Ruth P.; Felton, Gwen; Dishman, Rod K.; Dowda, Marsha

    2005-01-01

    Objectives. Many adolescent girls fail to meet national guidelines for physical activity, and the prevalence of obesity is increasing among this group. Our study examined the effects of a comprehensive school-based intervention on physical activity among high-school girls. Methods. A group-randomized controlled field trial was conducted at 24 high schools. A school-based sample of 2744 girls (48.7% African American, 46.7% White) participated in a measurement protocol when they were in eighth and then ninth grade. A comprehensive physical activity intervention was designed to change the instructional program and the school environment to increase support for physical activity among girls. Results. At follow-up, 45% of girls in the intervention schools and 36% of girls in the control schools reported vigorous physical activity during an average of 1 or more 30-minute time blocks per day over a 3-day period. Conclusions. A comprehensive school-based intervention can increase regular participation in vigorous physical activity among high-school girls. PMID:16118370

  12. Absence of TGF-β Receptor Activation by Highly Purified hCG Preparations.

    Science.gov (United States)

    Koistinen, Hannu; Hautala, Laura; Koli, Katri; Stenman, Ulf-Håkan

    2015-12-01

    Recently, several LH/human chorionic gonadotropin (hCG) receptor-independent activities for hCG have been described, including activation of the TGF-β receptor (TGFβR) by hyperglycosylated hCG and stimulation of trophoblast invasion. Because the hCG concentrations used in these studies have been rather high, reflecting physiological hCG levels in pregnancy, even a minor contamination with growth factors, which act at very low concentrations, may be significant. Several commercial hCG preparations have been found to contain significant amounts of epidermal growth factor (EGF), which we also confirmed here. Furthermore, we found that some hCG preparations also contain significant amounts of TGF-β1. These hCG preparations were able to activate ERK1/2 in JEG-3 choriocarcinoma cells or TGFβR in mink lung epithelial cells transfected with a reporter gene for TGFβR activation. No such activation was found with highly purified hCG or its free β-subunit (hCGβ), irrespective of whether they were hyperglycosylated or not. Taken together, our results suggest that the growth factor contaminations in the hCG preparations can cause activation of TGFβR and, at least in JEG-3 cells, MAPK signaling. This highlights the importance to carefully control for potential contaminations and that highly purified hCG preparations have to be used for biological studies.

  13. Active Learning Strategies for Phenotypic Profiling of High-Content Screens.

    Science.gov (United States)

    Smith, Kevin; Horvath, Peter

    2014-06-01

    High-content screening is a powerful method to discover new drugs and carry out basic biological research. Increasingly, high-content screens have come to rely on supervised machine learning (SML) to perform automatic phenotypic classification as an essential step of the analysis. However, this comes at a cost, namely, the labeled examples required to train the predictive model. Classification performance increases with the number of labeled examples, and because labeling examples demands time from an expert, the training process represents a significant time investment. Active learning strategies attempt to overcome this bottleneck by presenting the most relevant examples to the annotator, thereby achieving high accuracy while minimizing the cost of obtaining labeled data. In this article, we investigate the impact of active learning on single-cell-based phenotype recognition, using data from three large-scale RNA interference high-content screens representing diverse phenotypic profiling problems. We consider several combinations of active learning strategies and popular SML methods. Our results show that active learning significantly reduces the time cost and can be used to reveal the same phenotypic targets identified using SML. We also identify combinations of active learning strategies and SML methods which perform better than others on the phenotypic profiling problems we studied.

  14. [Central nervous system infections in HIV patients in the era of high activity antiretroviral treatment].

    Science.gov (United States)

    Rivas González, P; Fernández Guerrero, M L

    2005-06-01

    Although the incidence of most central nervous system infections in HIV+ patients has decreased after the introduction of the modern antiretroviral treatments, they are still a major cause of morbidity and mortality. New technologies in molecular biology and neuroradiology establish the diagnosis in many cases and have decreased the need for cerebral biopsy. Prognosis has improved substantially after the introduction of high activity antiretroviral treatment; more active treatments are needed, however, for infections as PML or citomegalovirus encephalitis because of their still unacceptably high mortality.

  15. Access to highly active antiretroviral therapy (HAART) in the WHO European Region 2003-2005

    DEFF Research Database (Denmark)

    Bollerup, Annemarie R; Donoghoe, Martin C; Lazarus, Jeff

    2008-01-01

    To assess changes in access to highly active antiretroviral therapy (HAART) between the end of 2002 and the end of 2005, and to review the capacity for further HAART scale-up in the then 52 Member States of the WHO European Region.......To assess changes in access to highly active antiretroviral therapy (HAART) between the end of 2002 and the end of 2005, and to review the capacity for further HAART scale-up in the then 52 Member States of the WHO European Region....

  16. Thermal Activation Analyses of Dynamic Fracture Toughness of High Strength Low Alloy Steels

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A formula is derived for determining the influence of temperatureand loading rate on dynamic fracture toughness of a high strength low alloy steel (HQ785C) from thermal activation analysis of the experimental results of three-point bend specimens as well as introducing an Arrhenius formula. lt is shown that the results obtained by the given formula are in good agreement with the experimental ones in the thermal activation region. The present method is also valuable to describe the relationship between dynamic fracture toughness and temperature and loading rate of other high strength low alloy steels.

  17. High-affinity benzodiazepine receptor ligands among benzodiazepines and betacarbolines with different intrinsic activity

    Energy Technology Data Exchange (ETDEWEB)

    Yliniemelae, A.; Gynther, J. (Univ. of Kuopio (Finland)); Konschin, H.; Tylli, H. (Univ. of Helsinki (Finland)); Rouvinen, J. (Univ. of Joensuu (Finland))

    1989-01-01

    Structural and electrostatic features of diazepam, flumazenil, and methyl betacarboline-3-carboxylate (BCCM) have been investigated using the molecular superimposition method. These high-affinity benzodiazepine (BZ) receptor ligands are structurally unrelated and they have different intrinsic activity. These ligands are superimposed in such a way that common structural and electrostatic features essential for the high receptor binding affinity overlap. In addition to this binding pharmacophore, there are roughly three separate binding zones in the BZ receptor, one for each class of ligands. The intrinsic activity of BZ receptor ligands depends on the molecular structures and the way the ligand approaches the receptor.

  18. The effect of high pressure homogenization on the activity of a commercial β-galactosidase.

    Science.gov (United States)

    Tribst, Alline A L; Augusto, Pedro E D; Cristianini, Marcelo

    2012-11-01

    High pressure homogenization (HPH) has been proposed as a promising method for changing the activity and stability of enzymes. Therefore, this research studied the activity of β-galactosidase before and after HPH. The enzyme solution at pH values of 6.4, 7.0, and 8.0 was processed at pressures of up to 150 MPa, and the effects of HPH were determined from the residual enzyme activity measured at 5, 30, and 45 °C immediately after homogenization and after 1 day of refrigerated storage. The results indicated that at neutral pH the enzyme remained active at 30 °C (optimum temperature) even after homogenization at pressures of up to 150 MPa. On the contrary, when the β-galactosidase was homogenized at pH 6.4 and 8.0, a gradual loss of activity was observed, reaching a minimum activity (around 30 %) after HPH at 150 MPa and pH 8.0. After storage, only β-galactosidase that underwent HPH at pH 7.0 retained similar activity to the native sample. Thus, HPH did not affect the activity and stability of β-galactosidase only when the process was carried out at neutral pH; for the other conditions, HPH resulted in partial inactivation of the enzyme. Considering the use of β-galactosidase to produce low lactose milk, it was concluded that HPH can be applied with no deleterious effects on enzyme activity.

  19. Tumorigenesis induced by the HHV8-encoded chemokine receptor requires ligand modulation of high constitutive activity

    DEFF Research Database (Denmark)

    Holst, P J; Rosenkilde, M M; Manfra, D;

    2001-01-01

    ORF74 (or KSHV-vGPCR) is a highly constitutively active G protein-coupled receptor encoded by HHV8 that is regulated both positively and negatively by endogenous chemokines. When expressed in transgenic mice, this chemokine receptor induces an angioproliferative disease closely resembling Kaposi...... sarcoma (KS). Here we demonstrate that several lines of mice carrying mutated receptors deficient in either constitutive activity or chemokine regulation fail to develop KS-like disease. In addition, animals expressing a receptor that preserves chemokine binding and constitutive activity but that does...

  20. Lipophilic vancomycin aglycon dimer with high activity against vancomycin-resistant bacteria.

    Science.gov (United States)

    Yarlagadda, Venkateswarlu; Sarkar, Paramita; Manjunath, Goutham B; Haldar, Jayanta

    2015-12-01

    Antibiotic-resistant superbugs such as vancomycin-resistant Enterococci (VRE) and Staphylococci have become a major global health hazard. To address this issue, we synthesized vancomycin aglycon dimers to systematically probe the impact of a linker on biological activity. A dimer having a pendant lipophilic moiety in the linker showed ∼300-fold more activity than vancomycin against VRE. The high activity of the compound is attributed to its enhanced binding affinity to target peptides which resulted in improved peptidoglycan (cell wall) biosynthesis inhibition. Therefore, our studies suggest that these compounds, prepared by using facile synthetic methodology, can be used to combat vancomycin-resistant bacterial infections.

  1. Impact of high (131)I-activities on quantitative (124)I-PET

    DEFF Research Database (Denmark)

    Braad, P E N; Hansen, Søren B.; Høilund-Carlsen, P F

    2015-01-01

    relevant [Formula: see text]I/[Formula: see text]I-activities were performed on a clinical PET/CT-system. Noise equivalent count rate (NECR) curves and quantitation accuracy were determined from repeated scans performed over several weeks on a decaying NEMA NU-2 1994 cylinder phantom initially filled...... [Formula: see text]I-activities was good and image quantification unaffected except at very high count rates. Quantitation accuracy and contrast recovery were uninfluenced at [Formula: see text]I-activities below 1000 MBq, whereas image noise was slightly increased. The NECR peaked at 550 MBq of [Formula...

  2. Promoting social skills of mexican high school students through virtual activities in the Moodle platform

    Directory of Open Access Journals (Sweden)

    Laura Yolanda RODRÍGUEZ MATAMOROS

    2014-11-01

    Full Text Available With the intention of promoting social skills of Mexican high school students based on the graduate profile of this level, virtual activities were implemented in the Moodle platform to 169 students of second year, adopting the proposed Goldstein social skills. In order to establish the impact of these activities to a pretest-postest a one group design was used. The results show that the activities had a positive and significant impact in beginning social skills, advanced social skills, skills for dealing with feeling, social alternatives skills of the participants according to the results obtained by skills scale social Goldstein.

  3. Effect of the ionic liquid [bmim]Cl and high pressure on the activity of cellulase

    OpenAIRE

    Salvador, Ângelo C.; Santos, Mickael Da C.; Saraiva, Jorge A.

    2010-01-01

    The effect of the ionic liquid 1-butyl-3-methylimidazolium chloride ([bmim]Cl) and of high pressure on the activity of cellulase from Aspergillus niger were studied separately and in combination. The enzyme activity decreased with increasing concentrations of [bmim]Cl, reaching 50% the value in aqueous buffer with 20% [bmim]Cl. However, when the enzyme is held in 10% [bmim]Cl and is then assayed in 1% [bmim]Cl, it showed only 8% reduction of activity. These results can be explained by the ...

  4. Vasopressin activates Akt/mTOR pathway in smooth muscle cells cultured in high glucose concentration

    Energy Technology Data Exchange (ETDEWEB)

    Montes, Daniela K.; Brenet, Marianne; Muñoz, Vanessa C.; Burgos, Patricia V.; Villanueva, Carolina I. [Department of Physiology, Universidad Austral de Chile, Valdivia 509-9200 (Chile); Figueroa, Carlos D. [Department of Anatomy, Histology and Pathology, Universidad Austral de Chile, Valdivia 509-9200 (Chile); González, Carlos B., E-mail: cbgonzal@uach.cl [Department of Physiology, Universidad Austral de Chile, Valdivia 509-9200 (Chile); Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555 (United States)

    2013-11-29

    Highlights: •AVP induces mTOR phosphorylation in A-10 cells cultured in high glucose concentration. •The mTOR phosphorylation is mediated by the PI3K/Akt pathway activation. •The AVP-induced mTOR phosphorylation inhibited autophagy and stimulated cell proliferation. -- Abstract: Mammalian target of rapamycin (mTOR) complex is a key regulator of autophagy, cell growth and proliferation. Here, we studied the effects of arginine vasopressin (AVP) on mTOR activation in vascular smooth muscle cells cultured in high glucose concentration. AVP induced the mTOR phosphorylation in A-10 cells grown in high glucose, in contrast to cells cultured in normal glucose; wherein, only basal phosphorylation was observed. The AVP-induced mTOR phosphorylation was inhibited by a PI3K inhibitor. Moreover, the AVP-induced mTOR activation inhibited autophagy and increased thymidine incorporation in cells grown in high glucose. This increase was abolished by rapamycin which inhibits the mTORC1 complex formation. Our results suggest that AVP stimulates mTOR phosphorylation by activating the PI3K/Akt signaling pathway and, subsequently, inhibits autophagy and raises cell proliferation in A-10 cells maintained in high glucose concentration.

  5. High inorganic phosphate causes DNMT1 phosphorylation and subsequent fibrotic fibroblast activation

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Xiaoying [Department of Nephrology and Rheumatology, Göttingen University Medical Center, Georg August University, Göttingen (Germany); Department of Cardiology and Pneumology, Göttingen University Medical Center, Georg August University, Göttingen (Germany); Xu, Xingbo [Department of Cardiology and Pneumology, Göttingen University Medical Center, Georg August University, Göttingen (Germany); Zeisberg, Elisabeth M. [Department of Cardiology and Pneumology, Göttingen University Medical Center, Georg August University, Göttingen (Germany); German Center for Cardiovascular Research (DZHK), Göttingen (Germany); Zeisberg, Michael, E-mail: mzeisberg@med.uni-goettingen.de [Department of Nephrology and Rheumatology, Göttingen University Medical Center, Georg August University, Göttingen (Germany); German Center for Cardiovascular Research (DZHK), Göttingen (Germany)

    2016-04-08

    Phosphate is an essential constituent of critical cellular functions including energy metabolism, nucleic acid synthesis and phosphorylation-dependent cell signaling. Increased plasma phosphate levels are an independent risk factor for lowered life-expectancy as well as for heart and kidney failure. Nevertheless, direct cellular effects of elevated phosphate concentrations within the microenvironment are poorly understood and have been largely neglected in favor of phosphor-regulatory hormones. Because interstitial fibrosis is the common determinant of chronic progressive kidney disease, and because fibroblasts are major mediators of fibrogenesis, we here explored the effect of high extracellular phosphate levels on renal fibroblasts. We demonstrate that high inorganic phosphate directly induces fibrotic fibroblast activation associated with increased proliferative activity, increased expression of α-smooth muscle actin and increased synthesis of type I collagen. We further demonstrate that such fibroblast activation is dependent on phosphate influx, aberrant phosphorylation of DNA methyltransferase DNMT1 and aberrant CpG island promoter methylation. In summary, our studies demonstrate that elevated phosphate concentrations induce pro-fibrotic fibroblast activation independent of phospho-regulatory hormones. - Highlights: • We exposed human kidney fibroblasts to media containing 1 mM or 3 mM phosphate. • Increased phosphate influx causes phosphorylation of DNA methyltransferase Dnmt1. • Phosphorylated Dnmt1 causes promoter methylation and transcriptional silencing of RASAL1. • Depletion of RASAL1 causes increased intrinsic Ras-GTP activity and fibroblast activation. • Inorganic phosphate causes fibroblast activation independent of phospho-regulatory hormones.

  6. Chemical stability of a cold-active cellulase with high tolerance toward surfactants and chaotropic agent

    Directory of Open Access Journals (Sweden)

    Thaís V. Souza

    2016-03-01

    Full Text Available CelE1 is a cold-active endo-acting glucanase with high activity at a broad temperature range and under alkaline conditions. Here, we examined the effects of pH on the secondary and tertiary structures, net charge, and activity of CelE1. Although variation in pH showed a small effect in the enzyme structure, the activity was highly influenced at acidic conditions, while reached the optimum activity at pH 8. Furthermore, to estimate whether CelE1 could be used as detergent additives, CelE1 activity was evaluated in the presence of surfactants. Ionic and nonionic surfactants were not able to reduce CelE1 activity significantly. Therefore, CelE1 was found to be promising candidate for use as detergent additives. Finally, we reported a thermodynamic analysis based on the structural stability and the chemical unfolding/refolding process of CelE1. The results indicated that the chemical unfolding proceeds as a reversible two-state process. These data can be useful for biotechnological applications.

  7. Long-Term Exposure to High Corticosterone Levels Inducing a Decrease of Adenylate Kinase 1 Activity

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yu'nan; SHEN Jia; SU Hui; HUANG Yufang; XING Dongming; DU Lijun

    2009-01-01

    Corticosterone, a principal glucocorticoid synthesized in the rodent adrenal cortex, can be cumula-tively toxic to hippocampal neurons, the cause of which is not known. The present study determined whether the cytosol adenylate kinase (AK) system was involved in the neuronal damage induced by long-term exposure to high corticosterone levels. We investigated the effects of long-term exposure to high corticosterone levels on AK1 activity, AK1 mRNA expression, and energy levels in cultured hippocampal neurons. The results show that long-term exposure to high corticosterone levels induces a reduction of the cultured hippocampal neuron viability, significantly reduces energy levels, and causes a time-dependant re-duction of the AK1 activity. These findings indicate that changes in the AK system might be the mechanism underlying neuronal damage induced by long-term exposure to high corticosterone levels.

  8. SU-E-T-543: Measurement of Neutron Activation From Different High Energy Varian Linear Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Thatcher, T; Madsen, S; Sudowe, R [University of Nevada, Las Vegas, Las Vegas, NV (United States); Meigooni, A Soleimani [University of Nevada, Las Vegas, Las Vegas, NV (United States); Comprehensive Cancer Center of Nevada, Las Vegas, Nevada (United States)

    2015-06-15

    Purpose: Linear accelerators producing photons above 10 MeV may induce photonuclear reactions in high Z components of the accelerator. These liberated neutrons can then activate the structural components of the accelerator and other materials in the beam path through neutron capture reactions. The induced activity within the accelerator may contribute to additional dose to both patients and personnel. This project seeks to determine the total activity and activity per activated isotope following irradiation in different Varian accelerators at energies above 10 MeV. Methods: A Varian 21IX accelerator was used to irradiate a 30 cm × 30 cm × 20 cm solid water phantom with 15 MV x-rays. The phantom was placed at an SSD of 100 cm and at the center of a 20 cm × 20 cm field. Activation induced gamma spectra were acquired over a 5 minute interval after 1 and 15 minutes from completion of the irradiation. All measurements were made using a CANBERRA Falcon 5000 Portable HPGe detector. The majority of measurements were made in scattering geometry with the detector situated at 90° to the incident beam, 30 cm from the side of the phantom and approximately 10 cm from the top. A 5 minute background count was acquired and automatically subtracted from all subsequent measurements. Photon spectra were acquired for both open and MLC fields. Results: Based on spectral signatures, nuclides have been identified and their activities calculated for both open and MLC fields. Preliminary analyses suggest that activities from the activation products in the microcurie range. Conclusion: Activation isotopes have been identified and their relative activities determined. These activities are only gross estimates since efficiencies have not been determined for this source-detector geometry. Current efforts are focused on accurate determination of detector efficiencies using Monte Carlo calculations.

  9. Physical activity in People with High Blood Pressure: A Case – control Study

    Directory of Open Access Journals (Sweden)

    M Momayyezi

    2016-03-01

    Full Text Available Introduction: Regular physical activity is one of the main factors in maintaining and improving health throughout life. International studies have shown that regular exercise can increase life expectancy and reduce morbidity and mortality from chronic diseases. This study was conducted to determine the amount of physical activity in people with high blood pressure and comparing them with healthy people. Methods: The present study was a case-control study on 160 people (80 patients with hypertension (case group and 80 healthy individuals (control group. People with normal blood pressure were in the case group and the control group (systolic 140 mmHg or above and diastolic 90 mmHg or above were in the case group. Data were collected using a questionnaire with the simple random sampling. The first part of questionnaire included background characteristics and socio-economic status; the second part of the questionnaire measured physical activity level using international physical activity questionnaire (IPAQ. The statistical analyses included descriptive statistics, the Mann–Whitney test, Chi-square test, and logistic regression analysis using SPSS/16. Assessment of physical activity in case and control groups showed that 13.8% of cases and 27.5% of controls had physical activity in the last week; this difference was statistically significant. Based on the results, the risk of hypertension in people without physical activity was 37.2 times more than the people who had physical activity in the last week. The results of logistic regression showed that physical activity, education level and income were effective factors on hypertension. The results showed that physical activity with moderate and severe levels have a protective effect against hypertension. Also, people with less income and less education had a greater chance of hypertension than others. The results indicated physical activity reduces the risk of hypertension. These findings emphasize

  10. Molecular scaffolds with high propensity to form multi-target activity cliffs.

    Science.gov (United States)

    Hu, Ye; Bajorath, Jürgen

    2010-04-26

    In target-dependent activity landscapes of compound series, cliffs are formed by pairs of molecules that are structurally analogous but display significant differences in potency. The detection and analysis of such activity cliffs is a major task in structure-activity relationship analysis and compound optimization. In analogy to activity cliffs, selectivity cliffs can be defined that are formed by structural analogs having significantly different potencies against two targets. The formation of activity cliffs by analogs is generally a consequence of different R-group patterns; e.g., a specific substitution of a given scaffold might increase and another substitution decrease potency. Therefore, activity (or selectivity) cliffs are typically analyzed for a given scaffold representing an analog series, and it has thus far not been explored whether certain scaffolds might display a general tendency to yield compounds forming activity cliffs against different targets. We have exhaustively analyzed scaffolds and associated compound activity data in the ChemblDB and BindingDB databases in order to compare the availability of target-selective scaffolds in these databases and determine whether multi-target activity and multi-target selectivity cliff scaffolds exist. Perhaps unexpectedly, we have identified 143 scaffolds that are represented by multiple compounds and form activity or selectivity cliffs against different targets. These scaffolds have varying chemical complexities and are in part promiscuous binders (i.e., compounds containing these scaffolds bind to distantly related or unrelated targets). However, analogs derived from these scaffolds form steep activity cliffs against different targets. A catalog of scaffolds with high propensity to form activity or selectivity cliffs against multiple targets is provided to help identify potentially promiscuous candidate scaffolds during compound optimization efforts.

  11. Program-Controlled High Voltage Module in Active Voltage Dividers(AVD) for MPGD

    CERN Document Server

    Ginting, Muhammad Fadhil

    2016-01-01

    Micro Pattern Gas Detectors (MPGD) applications are rapidly developing and became an important part of upgrades for the LHC detectors. RD51/CERN have worked on Active Voltage Divider (AVD) technology for multistage MPGDs, One of the next developments for the AVD is to design and integrate high voltage module in a single box. The Program-Controlled High Voltage Module, part of one AIDA2020 project, has been successfully designed and developed, and can be integrated in AVD design.

  12. Erectile Dysfunction Among HIV Patients Undergoing Highly Active Antiretroviral Therapy: Dyslipidemia as a Main Risk Factor

    Directory of Open Access Journals (Sweden)

    Gustavo Romero‐Velez, MD

    2014-04-01

    Conclusions: ED is highly prevalent in HIV patients. Dyslipidemia should be considered as a risk factor for ED in HIV patients. Romero‐Velez G, Lisker‐Cervantes A, Villeda‐Sandoval CI, Sotomayor de Zavaleta M, Olvera‐Posada D, Sierra‐Madero JG, Arreguin‐Camacho LO, and Castillejos‐Molina RA. Erectile dysfunction among HIV patients undergoing highly active antiretroviral therapy: Dyslipidemia as a main risk factor. Sex Med 2014;2:24–30.

  13. INVESTIGATION OF LEADERSHIP BEHAVIOR OF HIGH SCHOOL STUDENTS PARTICIPATING IN SPORTING RECREATION ACTIVITIES

    OpenAIRE

    Tugay; Fikret; Hüseyin

    2015-01-01

    In this study, with the aim of examining the size of the leadership in understanding the behavior of high school students participating in sports recreation activities it is a descriptive study. 206 women studying at different high schools in the province of Gaziantep research group, which consisted of 392 students, including 186 men. Data collection tool for research, Halpin and Winer (1957) developed by (Leader Behavior Description Qestionnair a) LBDQ scale, Turkish translated into shape...

  14. Preparation and Metallurgical Analysis of High Activity Burnt Lime for Steelmaking

    Institute of Scientific and Technical Information of China (English)

    Hua-qiang HAO; Yu-zhu ZHANG; Su-ju HAO; Chao-fa ZHANG; Wu-feng JIANG; Peng-hui CUI

    2016-01-01

    Burnt lime is an important material in steelmaking and its activity degree is a key factor for liquid steel quality.The burnt lime was made by the calcination of limestone in a high pressure electric furnace.The burnt lime mineralogical phases and micro-morphologies were characterized by X-ray diffraction (XRD)and field emission scan-ning electron microscopy (FE-SEM).The burnt lime activity degree was determined by acid-base titration,the burnt lime pore distribution was measured by mercury intrusion porosimetry (MIP),and the thermal effect of a mixture of burnt lime and slag was measured by differential scanning calorimetry (DSC).The results showed that the CaO grain size and pore size of burnt lime made under high pressure were larger than those of burnt lime made under atmos-pheric pressure.The CaO grain size and pore size increased and the laminate phenomenon also occurred clearly under high pressure.The activity degree of burnt lime made under high pressure was greater than that made under atmos-pheric pressure.The maximum activity degree was 437 mL for burnt lime made under a pressure of 0.4 MPa.For the same ratio of CaO to SiO2 ,the melting temperature,hemisphere temperature and fluidity temperature of slag decreased with increasing burnt lime activity degree.The higher the activity degree the burnt lime had,the better the slag forming occurred.It was advantageous for 2CaO.SiO2 and 3CaO.SiO2 forming at lower temperatures if the burnt lime activity degree was increased.

  15. Validation of the French version of two on high-activity knee questionnaires.

    Science.gov (United States)

    Diesinger, Y; Jenny, J-Y

    2014-09-01

    Self-administered quality-of-life questionnaires are valuable evaluation tools in orthopedic surgery. The conventional questionnaires are limited by a substantial ceiling effect. We wished to validate a French translation of two English questionnaires for high-activity patients: the High-Activity Arthroplasty Score (HAAS) and the Activity Scale for Arthroplasty Patients (ASAP). One hundred patients operated on for knee replacement were selected. The answers to both questionnaires were analyzed and compared to the Oxford Knee Score (OKS) and to the scoring system of the American Knee Society (AKS). There is no correlation between the results of both high-activity questionnaires and of the two conventional scoring systems. All questions were easily understood. The mean scores of the HAAS and ASAP questionnaires were 8.2±3.0 and 30.7±9.6, respectively. The distributions were not considered normal. There was no floor effect, but there was a limited ceiling effect (0% and 14%, respectively). The internal coherence of both questionnaires was satisfactory. There was a significant correlation between the high-activity scores and the conventional scores. Both high-activity questionnaires in our French translation can potentially measure the overall function of a patient after knee replacement as accurately as the index English version. It is self-administered, easy to use, can collect patients' answers by postage mailing, and involves no ceiling effect. All these points should allow its routine use for evaluation after knee replacement. The HAAS evaluation seems to be superior to the ASAP evaluation. Case-control study, level III. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  16. Altered expression of urokinase-type plasminogen activator and plasminogen activator inhibitor in high-risk soft tissue sarcomas.

    Science.gov (United States)

    Benassi, M S; Ponticelli, F; Azzoni, E; Gamberi, G; Pazzaglia, L; Chiechi, A; Conti, A; Spessotto, P; Scapolan, M; Pignotti, E; Bacchini, P; Picci, P

    2007-09-01

    In recent years, classification of soft-tissue sarcomas (STS) has improved with cytogenetic analyses, but their clinical behavior is still not easily predictable. The aim of this study was to detect alterations in the urokinase-type plasminogen system, involved in tumor growth and invasion, by comparing mRNA levels of its components with those of paired normal tissues, and relating them with patient clinical course. Real-time PCR was performed on human STS cell lines and tissues from highly malignant STS, including leiomyosarcomas and malignant fibrous histiocytomas, to evaluate the expression of urokinase-type plasminogen activator (uPA), uPA receptor (uPAR) and plasminogen activator inhibitor-1 (PAI-1). Immunohistochemistry of gene products was also performed. Median mRNA values of all genes studied were higher in tumors than in paired normal tissues. In agreement with data on STS cell lines, significant up-regulation for uPA and PAI-1 genes compared to reference values was seen. Moreover, different levels of expression were related to histotype and metastatic phenotype. There was accordance between uPA mRNA and protein expression, while immunodetection of PAI-1 product was weak and scattered. Clearly, the controversial role of PAI-1 protein requires further biological analyses, but evident involvement of uPA/PAI-1 gene overexpression in STS malignancy may highlight a molecular defect useful in discriminating STS high-risk patients.

  17. Physical activity, health, BMI and body complaints in high school students.

    Science.gov (United States)

    Alricsson, M; Landstad, B J; Romild, U; Gundersen, K T

    2008-02-01

    Children and adolescents in the industrial world are becoming less physically active and are adopting a sedentary lifestyle in front of computers and TV. The aim of the present investigation was to determine self-related health, physical activity, prevalence of overweight and body complaints in high school students in Norway, and to compare students in academic programs with those in vocational programs. Seven hundred and two high school students aged 16-19 years were included in the study. A questionnaire was completed in three high schools and included questions about weight and height, health, physical activity, type of physical activity/sport, intensity, possible injuries or complaints during the last three months. Twenty three percent of the students suffers from overweight/obesity are at risk of being overweight. Males reported better health than females (Pprograms reported poorer self-related health than those in academic programs and the males reported better self-related health generally than females. Furthermore, there were a higher level of prevalence of overweight students in vocational programs than academic programs (P=0.039). It is important to make it easy for school children and adolescents to do physical activity at school and during leisure time in order to prevent overweight and obesity as well as chronic diseases later in life.

  18. Overweight, physical activity and high blood pressure in children: a review of the literature.

    Science.gov (United States)

    Torrance, Brian; McGuire, K Ashlee; Lewanczuk, Richard; McGavock, Jonathan

    2007-01-01

    Obesity is a growing problem in developed countries and is likely a major cause of the increased prevalence of high blood pressure in children. The aim of this review is to provide clinicians and clinical scientists with an overview of the current state of the literature describing the negative influence of obesity on blood pressure and it's determinants in children. In short, we discuss the array of vascular abnormalities seen in overweight children and adolescents, including endothelial dysfunction, arterial stiffening and insulin resistance. We also discuss the potential role of an increased activation of the sympathetic nervous system in the development of high blood pressure and vascular dysfunction associated with obesity. As there is little consensus regarding the methods to prevent or treat high blood pressure in children, we also provide a summary of the evidence supporting relationship between physical activity and blood pressure in children and adolescents. After reviewing a number of physical activity intervention studies performed in children, it appears as though 40 minutes of moderate to vigorous aerobic-based physical activity 3-5 days/week is required to improve vascular function and reduce blood pressure in obese children. Future studies should focus on describing the influence of physical activity on blood pressure control in overweight children.

  19. A High-Q Active Inductor Circuit for Quasi-Millimeter-Wave Frequency Range

    Science.gov (United States)

    Masuda, Toru; Hattori, Yukio; Shikama, Hiroki; Hyogo, Akira

    This paper describes a novel high-Q active inductor circuit configuration composed of an operational transconductance amplifier (OTA) and an input RC network. Due to the phase rotation made by the input RC network, the active inductor circuit provides high-Q inductive impedance at higher frequencies. According to circuit simulation with design-kit of a 90-GHz-fT SiGe HBT technology, an inductance of more than 0.53nH and Q of more than 80 can be obtained at quasi-millimeter-wave frequency, 24GHz. The Q value is tunable by controlling the transconductance of the OTA. These features are also ensured by means of measurements of fabricated active inductor circuit. Since the active inductor circuit needs small chip area, which is 25% of a conventional passive inductor, the proposed active inductor contributes to implement a cost-effective high-Q notch filter for frequencies up to quasi-millimeter-wave frequencies.

  20. Removal of phenol by activated alumina bed in pulsed high-voltage electric field

    Institute of Scientific and Technical Information of China (English)

    ZHU Li-nan; MA Jun; YANG Shi-dong

    2007-01-01

    A new process for removing the pollutants in aqueous solution-activated alumina bed in pulsed high-voltage electric field was investigated for the removal of phenol under different conditions. The experimental results indicated the increase in removal rate with increasing applied voltage, increasing pH value of the solution, aeration, and adding Fe2+. The removal rate of phenol could reach 72.1 % when air aeration flow rate was 1200 ml/min, and 88.2 % when 0.05 mmol/L Fe2+ was added into the solution under the conditions of applied voltage 25 kV, initial phenol concentration of 5 mg/L, and initial pH value 5.5. The addition of sodium carbonate reduced the phenol removal rate. In the pulsed high-voltage electric field, local discharge occurred at the surface of activated alumina, which promoted phenol degradation in the thin water film. At the same time, the space-time distribution of gas-liquid phases was more uniform and the contact areas of the activated species generated from the discharge and the pollutant molecules were much wider due to the effect of the activated alumina bed. The synthetical effects of the pulsed high-voltage electric field and the activated alumina particles accelerated phenol degradation.

  1. CREATING OF BILINGUAL COMPETENCES OF HIGH SCHOOL STUDENTS BY MEANS OF PROJECT ACTIVITIES IN CONDITIONS OF INFORMATIZATION OF HIGH EDUCATION

    Directory of Open Access Journals (Sweden)

    G. A. Kruchinina

    2015-01-01

    Full Text Available Public information and communication space is a favorable environment for the development of bilingualism. Modern communication bilingual techniques may be more effective with the use of computer technology. The article investigates the necessity and possibility of the use of information and communication technologies in the project activities at the professional training of bilingual foreign language in high school. The combination of a method of projects and information and communication technologies (ICT in the teaching of foreign languages allows you to save interest in learning through the creative potential of a student, increasing motivation, independence and initiative. Using information and communication technologies, along with other modern pedagogical technologies (such as cooperative learning, project methodology, and others. helps to implement the studentcentered approach to learning, providing individualization and differentiation of education taking into account the abilities of students, their level of training; to form a stable motivation of foreign language activities in the classroom through the use of authentic materials, discuss pressing issues; to improve the skills of education and self-education, to move from reproductive assimilation of information to interactive and productive forms of education. The article presents the results of the study to assess the degree of attraction for students of various activities with the use of ICT in professional and bilingual foreign language training.

  2. Activated carbon fibers with a high content of surface functional groups by phosphoric acid activation of PPTA.

    Science.gov (United States)

    Castro-Muñiz, Alberto; Suárez-García, Fabián; Martínez-Alonso, Amelia; Tascón, Juan M D

    2011-09-01

    Activated carbon fibers (ACFs) were prepared by chemical activation of poly(p-phenylene terephthalamide (PPTA) with phosphoric acid, with a particular focus on the effects of impregnation ratio and carbonization temperature on both surface chemistry and porous texture. Thermogravimetric studies of the pyrolysis of PPTA impregnated with different amounts of phosphoric acid indicated that this reagent has a strong influence on the thermal degradation of the polymer, lowering the decomposition temperature and increasing the carbon yield. As concerns surface chemistry, TPD and chemical analysis results indicated that the addition of phosphoric acid increases the concentration of oxygenated surface groups, with a maximum at an impregnation ratio of 100 wt.%. The resulting materials present uncommon properties, namely a large amount of oxygen- and phosphorus-containing surface groups and a high nitrogen content. Porosity development following H(3)PO(4) activation was very significant, with values close to 1700 m(2)/g and 0.80 cm(3)/g being reached for the BET surface area and total pore volume, respectively. The pore size distributions remained confined to the micropore and narrow mesopore (<10 nm) range.

  3. Health-Related Fitness Knowledge and Physical Activity of High School Students

    Science.gov (United States)

    Thompson, Angela; Hannon, James C.

    2012-01-01

    The purpose of this study was to determine if health-related fitness (HRF) knowledge is related to self-reported physical activity (PA) of high school students. Students (N=165) enrolled in physical education from two schools in the Southwestern U.S participated. A 100-point HRF knowledge test was assembled, focusing on the HRF concepts of…

  4. Heart Rates of High School Physical Education Students during Team Sports, Individual Sports, and Fitness Activities

    Science.gov (United States)

    Laurson, Kelly R.; Brown, Dale D.; Cullen, Robert W.; Dennis, Karen K.

    2008-01-01

    This study examined how activity type influenced heart rates and time spent in target heart rate zones of high school students participating in physical education classes. Significantly higher average heart rates existed for fitness (142 plus or minus 24 beats per minute [bpm]) compared to team (118 plus or minus 24 bpm) or individual (114 plus or…

  5. High Frequency AC Inductor Analysis and Design for Dual Active Bridge (DAB) Converters

    DEFF Research Database (Denmark)

    Zhang, Zhe; Andersen, Michael A. E.

    2016-01-01

    The dual active bridge (DAB) converter is an isolated bidirectional dc-dc topology which is the most critical part for the power conversion systems such as solid-state transformers (SST). This paper focuses on analysis and design of high frequency ac inductors which are the power interfacing...

  6. Stable amorphous georgeite as a precursor to a high-activity catalyst

    DEFF Research Database (Denmark)

    Kondrat, Simon A.; Smith, Paul J.; Wells, Peter P.

    2016-01-01

    and solvation power of supercritical carbon dioxide to rapidly expand and supersaturate solutions, can be used to prepare copper/zinc hydroxycarbonate precursors with low sodium content. These include stable georgeite, which we find to be a precursor to highly active methanol-synthesis and superior LTS...

  7. Implementing an Inexpensive and Accurate Introductory Gas Density Activity with High School Students

    Science.gov (United States)

    Cunningham, W. Patrick; Joseph, Christopher; Morey, Samantha; Santos Romo, Ana; Shope, Cullen; Strang, Jonathan; Yang, Kevin

    2015-01-01

    A simplified activity examined gas density while employing cost-efficient syringes in place of traditional glass bulbs. The exercise measured the density of methane, with very good accuracy and precision, in both first-year high school and AP chemistry settings. The participating students were tasked with finding the density of a gas. The…

  8. Effects of high hydrostatic pressure on genomic expression profiling of porcine parthenogenetic activated and cloned embryos

    DEFF Research Database (Denmark)

    Lin, Lin; Luo, Yonglun; Sørensen, Peter

    2014-01-01

    Handmade cloning (HMC) has been used to generate transgenic pigs for biomedical research. Recently, we found that parthenogenetic activation (PA) of porcine oocytes and improved HMC efficiency could be achieved by treatment with sublethal high hydrostatic pressure (HHP). However, the molecular...

  9. Detection of lipoatrophy in human immunodeficiency virus-1-infected children treated with highly active antiretroviral therapy.

    NARCIS (Netherlands)

    Hartman, K.; Verweel, G.; Groot, R. de; Hartwig, N.G.

    2006-01-01

    BACKGROUND: Highly active antiretroviral therapy has been associated with lipodystrophy in adults. Much is unknown about its characteristics, especially in children. OBJECTIVE: To obtain an objective case definition of the lipodystrophy syndrome. METHODS: This was a cross-sectional study. One invest

  10. Prevalence of Lipodystrophy in HIV-infected Children in Tanzania on Highly Active Antiretroviral Therapy

    NARCIS (Netherlands)

    Kinabo, G.; Sprengers, M.; Msuya, L.J.; Shayo, A.M.; Asten, H.A.G.H. van; Dolmans, W.M.V.; Ven, A.J.A.M. van der; Warris, A.

    2013-01-01

    OBJECTIVE: : Highly active antiretroviral therapy (HAART) has been associated with lipodystrophy (LD) in adults but data are more limited for children. The purpose of this study was to determine the prevalence of and risk factors for LD in Tanzanian children receiving HAART by clinical assessment an

  11. Esterification and transesterification of greases to fatty acid methyl esters with highly active diphanylammonium salts

    Science.gov (United States)

    We have conducted an investigation designed to identify alternate catalysts for the production of fatty acid methyl esters (FAME) to be used as biodiesel. Diphenylammonium sulfate (DPAS) and diphenylammonium chloride (DPA-HCl) salts were found to be highly active homogeneous catalysts for the simu...

  12. Esterification and Transesterification of greases to fatty acid methyl esters with highly active diphenylamine salts

    Science.gov (United States)

    Diphenylamine sulfate (DPAS) and diphenylamine hydrochloride (DPACl) salts were found to be highly active catalysts for esterification and transesterification of inexpensive greases to fatty acid methyl esters (FAME). In the presence of catalytic amounts of DPAS or DPACl and excess methanol, the fr...

  13. Critical currents and thermally activated flux motion in high-temperature superconductors

    NARCIS (Netherlands)

    Palstra, T.T.M.; Batlogg, B.; Dover, R.B. van; Schneemeyer, L.F.; Waszczak, J.V.

    1989-01-01

    We have measured the resistance below Tc of single crystals of the high-temperature superconductors Ba2YCu3O7 and Bi2.2Sr2Ca0.8Cu2O8+δ in magnetic fields up to 12 T. The resistive transition of both compounds is dominated by intrinsic dissipation which is thermally activated, resulting in an exponen

  14. A Multi-Institutional Examination of the Relationships between High School Activity Involvement and Leadership Characteristics

    Science.gov (United States)

    Simonsen, Jon C.; Velez, Jonathan J.; Foor, Ryan M.; Birkenholz, Robert J.; Foster, Daniel D.; Wolf, Kattlyn J.; Epps, Rebekah B.

    2014-01-01

    Developing leaders is vital to the future of our nation. As institutions of higher education address the need for leadership through courses and experiences, there is a need to recognize and acknowledge the potential impact of high school activity participation on leadership development. This descriptive-correlational study surveyed first-time…

  15. Laser thermal annealing of Ge, optimized for highly activated dopants and diode ION/IOFF ratios

    DEFF Research Database (Denmark)

    Shayesteh, M.; O'Connell, D.; Gity, F.;

    2014-01-01

    The authors compared the influence of laser thermal annealing (LTA) and rapid thermal annealing (RTA) on dopant activation and electrical performance of phosphorus and arsenic doped n+/p junction. High carrier concentration above 1020 cm-3 as well as an ION/IOFF ratio of approximately 105 and ide...

  16. Writing Chemistry Jingles as an Introductory Activity in a High School Chemistry Class

    Science.gov (United States)

    Heid, Peter F.

    2011-01-01

    Starting the school year in an introductory high school chemistry class can be a challenge. The topic and approach is new to the students; many of the early chapters in the texts can be a bit tedious; and for many students the activities are uninspiring. My goal in the first few weeks of school is to hook the students on chemistry by getting them…

  17. Calcium Oxide Supported on Monoclinic Zirconia as a Highly Active Solid Base Catalyst

    NARCIS (Netherlands)

    Frey, A.M.; Haasterecht, van T.; Jong, de K.P.; Bitter, J.H.

    2013-01-01

    Calcium oxide supported on ZrO2 is a highly active catalyst for base-catalyzed reactions such as aldol-type reactions and transesterification reactions. The role of key parameters during preparation, that is, impregnation versus precipitation, heat treatment, and metal oxide loading on the basicity

  18. HIGH-THROUGHPUT IDENTIFICATION OF CATALYTIC REDOX-ACTIVE CYSTEINE RESIDUES

    Science.gov (United States)

    Cysteine (Cys) residues often play critical roles in proteins; however, identification of their specific functions has been limited to case-by-case experimental approaches. We developed a procedure for high-throughput identification of catalytic redox-active Cys in proteins by se...

  19. Increased physical activity ameliorates high fat diet-induced bone resorption in mice

    Science.gov (United States)

    It has been recognized that mechanical stresses associated with physical activity (PA) have beneficial effects on increasing bone mineral density (BMD) and improving bone quality. On the other hand, high fat diet (HFD) and obesity increase bone marrow adiposity leading to increased excretion of pro-...

  20. Transforming Principles into Practice: Using Cognitive Active Learning Strategies in the High School Classroom

    Science.gov (United States)

    Swiderski, Suzanne M.

    2011-01-01

    High school teachers who engage students through active learning in their classrooms can more fully understand this instructional practice by examining the theories and strategies underlying the cognitive perspective of educational psychology, which addresses the development of knowledge in the individual mind. Two theoretical explanations,…

  1. High fat fed heart failure animals have enhanced mitochondrial function and acyl-coa dehydrogenase activities

    Science.gov (United States)

    We have previously shown that administration of high fat in heart failure (HF) increased mitochondrial respiration and did not alter left ventricular (LV) function. PPARalpha is a nuclear transcription factor that activates expression of genes involved in fatty acid uptake and utilization. We hypoth...

  2. Synthesis of tritium-labelled imipramine and desipramine with high specific activities

    Energy Technology Data Exchange (ETDEWEB)

    Yakovleva, L.A.; Kaminski, Ju.L.; Sosnova, L.P.; Kudelin, B.K. (Khlopin Radium Inst., St. Petersburg (Russian Federation))

    1992-09-01

    [G-[sup 3]H]imipramine and [G-[sup 3]H] desipramine with specific activities 110-160 and 80-100 kCi/mol, respectively were synthesized by high temperature solid-phase catalytic isotope exchange with gaseous tritium. (author).

  3. Heart Rates of High School Physical Education Students during Team Sports, Individual Sports, and Fitness Activities

    Science.gov (United States)

    Laurson, Kelly R.; Brown, Dale D.; Cullen, Robert W.; Dennis, Karen K.

    2008-01-01

    This study examined how activity type influenced heart rates and time spent in target heart rate zones of high school students participating in physical education classes. Significantly higher average heart rates existed for fitness (142 plus or minus 24 beats per minute [bpm]) compared to team (118 plus or minus 24 bpm) or individual (114 plus or…

  4. Self-related health, physical activity and complaints in Swedish high school students.

    Science.gov (United States)

    Alricsson, Marie; Landstad, Bodil J; Romild, Ulla; Werner, Suzanne

    2006-07-18

    The aim of this investigation was to study self-related health, physical activity and level of exertion, as well as body complaints in Swedish high school students. A total of 993 high school students aged 16-19 years participated in the study. A questionnaire was completed at school and included questions about self-related health, physical activity behavior, type of physical activity/sport, intensity, duration, possible injuries or complaints, and absence from physical training at school, during the last 3 months. The results showed that 26% of the high school students participated in sports on a regular basis. Males reported significantly better health than females (p health than those without complaints. There was a correlation between poor self-related health and a lower level of physical effort (0.219; p musculoskeletal symptoms was high in this population and demonstrated a certain association with self-related health. Therefore, it is important to make it easy for adolescents to perform physical activity at school and during their leisure time in order to prevent chronic diseases.

  5. A Highly Active and Selective Manganese Oxide Promoted Cobalt-on-Silica Fischer-Tropsch Catalyst

    NARCIS (Netherlands)

    den Breejen, Johan P.; Frey, Anne M.; Yang, Jia; Holmen, Anders; van Schooneveld, Matti M.; de Groot, Frank M. F.; Stephan, Odile; Bitter, Johannes H.; de Jong, Krijn P.

    2011-01-01

    A highly active and selective manganese oxide-promoted silica-supported cobalt catalyst for the Fischer-Tropsch reaction is reported. Co/MnO/SiO2 catalysts were prepared via impregnation of a cobalt nitrate and manganese nitrate precursor, followed by drying and calcination in an NO/He flow. The cat

  6. Low powdered activated carbon concentrations to improve MBR sludge filterability at high salinity and low temperature

    NARCIS (Netherlands)

    Remy, M.J.J.; Temmink, B.G.; Brink, van den P.; Rulkens, W.H.

    2011-01-01

    Previous research has demonstrated that powdered activated carbon (PAC), when applied at very low dosages and long SRTs, reduces membrane fouling in membrane bioreactor (MBRs). This effect was related to stronger flocs which are less sensitive to shear. Low temperature and high salt concentration ar

  7. Is Political Activism Still a "Masculine" Endeavor? Gender Comparisons among High School Political Activists.

    Science.gov (United States)

    Romer, Nancy

    1990-01-01

    Analyzes differences among high school political activists with conservative, liberal, and left perspectives. Discusses gender differences in the Bem Sex Role Inventory and other politically associated behaviors. No gender differences were found on extent of political activity. Females more often presented future family life as a limitation on…

  8. Characterization of Catalase from Psychrotolerant Psychrobacter piscatorii T-3 Exhibiting High Catalase Activity

    Directory of Open Access Journals (Sweden)

    Hidetoshi Matsuyma

    2012-02-01

    Full Text Available A psychrotolerant bacterium, strain T-3 (identified as Psychrobacter piscatorii, that exhibited an extraordinarily high catalase activity was isolated from the drain pool of a plant that uses H2O2 as a bleaching agent. Its cell extract exhibited a catalase activity (19,700 U·mg protein−1 that was higher than that of Micrococcus luteus used for industrial catalase production. Catalase was approximately 10% of the total proteins in the cell extract of the strain. The catalase (PktA was purified homogeneously by only two purification steps, anion exchange and hydrophobic chromatographies. The purified catalase exhibited higher catalytic efficiency and higher sensitivity of activity at high temperatures than M. luteus catalase. The deduced amino acid sequence showed the highest homology with catalase of Psycrobacter cryohalolentis, a psychrotolelant bacterium obtained from Siberian permafrost. These findings suggest that the characteristics of the PktA molecule reflected the taxonomic relationship of the isolate as well as the environmental conditions (low temperatures and high concentrations of H2O2 under which the bacterium survives. Strain T-3 efficiently produces a catalase (PktA at a higher rate than Exiguobacterium oxidotolerans, which produces a very strong activity of catalase (EktA at a moderate rate, in order to adapt to high concentration of H2O2.

  9. Novel high-activity catalysts for partial oxidation of methane to formaldehyde

    CSIR Research Space (South Africa)

    Parmaliana, A

    1993-05-07

    Full Text Available Vanadium oxide-silica catalysts can effect the partial oxidation of methane to formaldehyde with extremely high activities and the space time yield (STY) can reach a value in excess of 800 g kg-1cat h-1; bare silica also shows appreciable STY value...

  10. Geography of the Olympic Games: A Geographic Learning Activity for Upper Elementary and Junior High Schools.

    Science.gov (United States)

    Hodgman, Leonard; Lennert, James W.

    1996-01-01

    Presents a learning activity for students in upper elementary and junior high schools that capitalizes on the appeal of the Olympic Games. Using statistical information on the Games, students are asked to generate world maps indicating medal-winning countries. Includes sample Olympic data and maps. (DSK)

  11. Low-jitter and high-power 40 GHz all-active mode-locked lasers

    DEFF Research Database (Denmark)

    Yvind, Kresten; Larsson, David; Christiansen, Lotte Jin

    2004-01-01

    A novel design strategy for the epitaxial structure of monolithic mode-locked semiconductor lasers is presented. Using an all-active design, we fabricate 40-GHz lasers generating 2.8-ps almost chirp-free pulses with record low high-frequency jitter and more than 7-mW fiber coupled output power....

  12. A High-Throughput MALDI-TOF Mass Spectrometry-Based Assay of Chitinase Activity

    Science.gov (United States)

    A high-throughput MALDI-TOF mass spectrometric assay is described for assay of chitolytic enzyme activity. The assay uses unmodified chitin oligosaccharide substrates, and is readily achievable on a microliter scale (2 µL total volume, containing 2 µg of substrate and 1 ng of protein). The speed a...

  13. The Association between Premenstrual Syndrome and Physical Activity and Aerobic Power in Female High School Students

    Directory of Open Access Journals (Sweden)

    Sabaei Yekta

    2015-04-01

    Full Text Available Objective: The purpose of this study was to investigate the relationship between premenstrual syndrome (PMS and physical activity, aerobic power, and anaerobic power in female high school students. Materials and Methods: A total of 367 female high school students were selected randomly from district 5 of Tehran. Among them, 40 students who had the highest PMS score and all the inclusion criteria of the study were selected as subjects. The level of physical activity was assessed using the Baecke Physical Activity Questionnaire and PMS was assessed using a self-report questionnaire. Aerobic power was assessed using submaximal 1-mile track jog test. Pearson’s correlation coefficient was used for analyzing the relationship between variables. Results: The results indicated a significant negative correlation between PMS and physical activity (r = -0.86 and P < 0.05 and aerobic power (r = -0.71 and P < 0.05. Conclusion: Based on the findings, it seems that regular physical activity, especially aerobic activities, can be effective in reducing the symptoms of PMS.

  14. High versus low radioiodine activity in patients with differentiated thyroid cancer - A meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Valachis, Antonis [Dept. of Oncology, Maelarsjukhuset., Eskilstuna (Sweden); Univ. of Uppsala,, (Sweden)], e-mail: Valachis@hotmail.com, Antonis.Valachis@akademiska.uu.se; Nearchou, Andreas [Dept, of Oncology, Maelarsjukhuset., Eskilstuna (Sweden); Univ. of Uppsala., Uppsala (Sweden)

    2013-08-15

    Background: The purpose of the meta-analysis was to estimate the effectiveness and toxicity of low activity radioiodine ablation versus high activity in patients with differentiated thyroid cancer (DTC). Design: A systematic review and meta-analysis was performed by including all randomized trials of low activity versus high activity radioiodine ablation after thyroidectomy. Standard meta-analytic procedures were used to analyze the study outcomes. Results: Ten trials were considered eligible and were further analyzed. The pooled risk ratio (RR) of having a successful ablation for an activity of 1100 MBq versus 3700 MBq (seven trials, 1772 patients) was 0.94 (95% CI 0.85 - 1.04, p-value 0.21). The RR for successful ablation when only thyroid hormone withdrawal was used (five trials, 1116 patients) was 0.87 (95% CI 0.72 - 1.06, p-value 0.17) and it was comparable to RR when only recombinant-human TSH (rec-hTSH) (two trials, 812 patients) was used (1.00, 95% CI 0.93 - 1.07, p-value 0.92). Salivary dysfunction, nausea, and neck pain were significantly more frequent among patients with higher dose for ablation. Conclusion: Our meta-analysis provides some evidence from randomized trials that a lower activity of radioiodine ablation is as effective as higher dose after surgery in patients with DTC with lower toxicity.

  15. Examination of the Effect of High School Students Physical Activity Levels on Their Problem Solving Skills

    Directory of Open Access Journals (Sweden)

    Nimet Korkmaz

    2017-06-01

    Full Text Available The purpose of this study is to be knowledgeable with demographic characteristics, Body mass index, physical activity levels, problem solving skills and sub-dimensions of the students receiving education at Anatolia High Schools and examine the effect of the physical activity levels of these students on their problem solving skills. The population of the study was included a total of 451 students (female=264; male=187 receiving education at the Anatolia High Schools in the Osmangazi district. In this study, the data was collected via the “International Physical Activity Questionnaire-Short Form” and the “Problem Solving Skill Scale” (PSS. It was determined that the males’ physical activity values (3822.85 MET- min./week, were higher compared to those of the females (2103.17. On the contrary, the problem solving skills of the males (mean 2.91 were lower than those of the females (mean 2.95. The SPSS 23.0 for Windows program was used in the statistical analyses of the data. In order to see if the data distributed normally or not, Tabachnick and Fidell coefficients were used for the kurtosis and skewness values. For the comparison of the problem solving skills scores and the physical activity scores, the t test statistical method was used. In conclusion, no significant relationship at p<0.05 level was determined between the students’ problem solving skills and their physical activity states.

  16. A SYSTEMATIC SURVEY OF HIGH-TEMPERATURE EMISSION IN SOLAR ACTIVE REGIONS

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Winebarger, Amy R. [NASA Marshall Space Flight Center, VP 62, Huntsville, AL 35812 (United States); Brooks, David H. [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States)

    2012-11-10

    The recent analysis of observations taken with the EUV Imaging Spectrometer and X-Ray Telescope instruments on Hinode suggests that well-constrained measurements of the temperature distribution in solar active regions can finally be made. Such measurements are critical for constraining theories of coronal heating. Past analysis, however, has suffered from limited sample sizes and large uncertainties at temperatures between 5 and 10 MK. Here we present a systematic study of the differential emission measure distribution in 15 active region cores. We focus on measurements in the 'inter-moss' region, that is, the region between the loop footpoints, where the observations are easier to interpret. To reduce the uncertainties at the highest temperatures we present a new method for isolating the Fe XVIII emission in the AIA/SDO 94 A channel. The resulting differential emission measure distributions confirm our previous analysis showing that the temperature distribution in an active region core is often strongly peaked near 4 MK. We characterize the properties of the emission distribution as a function of the total unsigned magnetic flux. We find that the amount of high-temperature emission in the active region core is correlated with the total unsigned magnetic flux, while the emission at lower temperatures, in contrast, is inversely related. These results provide compelling evidence that high-temperature active region emission is often close to equilibrium, although weaker active regions may be dominated by evolving million degree loops in the core.

  17. Zelda overcomes the high intrinsic nucleosome barrier at enhancers during Drosophila zygotic genome activation.

    Science.gov (United States)

    Sun, Yujia; Nien, Chung-Yi; Chen, Kai; Liu, Hsiao-Yun; Johnston, Jeff; Zeitlinger, Julia; Rushlow, Christine

    2015-11-01

    The Drosophila genome activator Vielfaltig (Vfl), also known as Zelda (Zld), is thought to prime enhancers for activation by patterning transcription factors (TFs). Such priming is accompanied by increased chromatin accessibility, but the mechanisms by which this occurs are poorly understood. Here, we analyze the effect of Zld on genome-wide nucleosome occupancy and binding of the patterning TF Dorsal (Dl). Our results show that early enhancers are characterized by an intrinsically high nucleosome barrier. Zld tackles this nucleosome barrier through local depletion of nucleosomes with the effect being dependent on the number and position of Zld motifs. Without Zld, Dl binding decreases at enhancers and redistributes to open regions devoid of enhancer activity. We propose that Zld primes enhancers by lowering the high nucleosome barrier just enough to assist TFs in accessing their binding motifs and promoting spatially controlled enhancer activation if the right patterning TFs are present. We envision that genome activators in general will utilize this mechanism to activate the zygotic genome in a robust and precise manner.

  18. Thermal activation approaches to deformation mechanisms for high Nb containing TiAl base alloys

    Institute of Scientific and Technical Information of China (English)

    刘自成; 王艳丽; 林均品; 张卫军; 陈国良

    2002-01-01

    The deformation mechanisms in a wide temperature range from room temperature to 1200K were investigated by thermal activation approach. Using observed instantaneous stress response to the strain rate jump (Δσtr), the activation volume Va, then the activation enthalpy ΔH, activation free enthalpy ΔG and activation entropy ΔS were calculated. The apparent activation energy of high temperature deformation is estimated to be 3.66eV, which is larger than the self-diffusion coefficient of binary TiAl (3.01eV). The dislocations at 1173K are generally curved or bowed, even helical-shaped dislocations. The climb of ordinary dislocations as well as twinning has greatly contributed to the plastic deformation. The CRSS at 1173K is estimated to be 180MPa. The higher resisting stress at both room temperature and elevated temperature might relate to the high Nb content of the alloy.

  19. Dopaminergic parameters during social isolation in low- and high-active mice.

    Science.gov (United States)

    Rilke, O; Jähkel, M; Oehler, J

    1998-06-01

    Alterations induced by social isolation (1 day to 18 weeks) in low- and high-active mice (LAM and HAM) were studied in respect to locomotor activity, [3H]-spiperone binding in the striatum, striatal, and cortical dopamine metabolism, and presynaptic dopaminergic sensitivity to apomorphine (0.75 mg/kg; i.p.). Isolated HAM and LAM showed increased locomotor activity compared to group-housed mice after long-term isolation (6-18 weeks). Considering the studied dopaminergic parameters, it has been found that social isolation did not affect striatal D2 receptors, striatal and cortical dopamine metabolism, and apomorphine-mediated reduction of dopaminergic metabolism. The change of housing conditions was generally associated with an increase of cortical dopamine metabolism after 1 week. Activity type specific differences in group-housed LAM and HAM were found in the basal striatal dopamine metabolism and in the sensitivity of the nigrostriatal system to autoreceptor activation. The reduced striatal dopamine metabolism and the higher presynaptic sensitivity of HAM may be related to their high active running wheel behavior.

  20. Preparation and Characterization of High Surface Area Activated Carbon Fibers from Lignin

    Directory of Open Access Journals (Sweden)

    Jian Lin

    2016-10-01

    Full Text Available Activated carbon fibers (ACFs were successfully prepared from softwood lignin, which was isolated with polyethylene glycol 400 (PEG-400 as a solvolysis reagent, by water steam activation. The pore characterization and adsorption property of ACFs were investigated. The results showed that all the ACFs with more micropores exhibited high specific surface area and total pore volume which increased with the activation time prolonging; the highest ones were around 3100 m2/g and 1.5 mL/g, respectively. The specific surface area and total pore volume were much larger than those of other types of lignin-based ACFs and activated charcoal. Besides, with increasing activation time, the amount of graphitic carbon, which was the main compound on the surface of ACFs, decreased, while the amount of functional groups containing C–O slightly increased. In addition, the adsorption capacity of ACFs for methylene blue was highly increased as the activation time increased. Accordingly, lignin isolated with PEG is a promising precursor for ACF production.

  1. Biphasic catalysis using amphiphilic polyphenols-chelated noble metals as highly active and selective catalysts

    Science.gov (United States)

    Mao, Hui; Yu, Hong; Chen, Jing; Liao, Xuepin

    2013-07-01

    In the field of catalysis, it is highly desired to develop novel catalysts that combine the advantages of both homogeneous and heterogeneous catalysts. Here we disclose that the use of plant pholyphenol as amphiphilic large molecule ligand/stabilizer allows for the preparation of noble metal complex and noble metal nanoparticle catalysts. These catalysts are found to be highly selective and active in aqueous-organic biphasic catalysis of cinnamaldehyde and quinoline, and can be reused at least 3 times without significant loss of activity. Moreover, the catalytic activity and reusability of the catalysts can be rationally controlled by simply adjusting the content of polyphenols in the catalysts. Our strategy may be extended to design a wide range of aqueous-organic biphasic catalysis system.

  2. C-H bond activation by metal-superoxo species: what drives high reactivity?

    Science.gov (United States)

    Ansari, Azaj; Jayapal, Prabha; Rajaraman, Gopalan

    2015-01-01

    Metal-superoxo species are ubiquitous in metalloenzymes and bioinorganic chemistry and are known for their high reactivity and their ability to activate inert C-H bonds. The comparative oxidative abilities of M-O2(.-) species (M = Cr(III), Mn(III), Fe(III), and Cu(II)) towards C-H bond activation reaction are presented. These superoxo species generated by oxygen activation are found to be aggressive oxidants compared to their high-valent metal-oxo counterparts generated by O⋅⋅⋅O bond cleavage. Our calculations illustrate the superior oxidative abilities of Fe(III)- and Mn(III)-superoxo species compared to the others and suggest that the reactivity may be correlated to the magnetic exchange parameter.

  3. High-density localization of active molecules using Structured Sparse Model and Bayesian Information Criterion.

    Science.gov (United States)

    Quan, Tingwei; Zhu, Hongyu; Liu, Xiaomao; Liu, Yongfeng; Ding, Jiuping; Zeng, Shaoqun; Huang, Zhen-Li

    2011-08-29

    Localization-based super-resolution microscopy (or called localization microscopy) rely on repeated imaging and localization of active molecules, and the spatial resolution enhancement of localization microscopy is built upon the sacrifice of its temporal resolution. Developing algorithms for high-density localization of active molecules is a promising approach to increase the speed of localization microscopy. Here we present a new algorithm called SSM_BIC for such purpose. The SSM_BIC combines the advantages of the Structured Sparse Model (SSM) and the Bayesian Information Criterion (BIC). Through simulation and experimental studies, we evaluate systematically the performance between the SSM_BIC and the conventional Sparse algorithm in high-density localization of active molecules. We show that the SSM_BIC is superior in processing single molecule images with weak signal embedded in strong background.

  4. Human PHOSPHO1 exhibits high specific phosphoethanolamine and phosphocholine phosphatase activities

    Science.gov (United States)

    2004-01-01

    Human PHOSPHO1 is a phosphatase enzyme for which expression is upregulated in mineralizing cells. This enzyme has been implicated in the generation of Pi for matrix mineralization, a process central to skeletal development. PHOSPHO1 is a member of the haloacid dehalogenase (HAD) superfamily of Mg2+-dependent hydrolases. However, substrates for PHOSPHO1 are, as yet, unidentified and little is known about its activity. We show here that PHOSPHO1 exhibits high specific activities toward phosphoethanolamine (PEA) and phosphocholine (PCho). Optimal enzymic activity was observed at approx. pH 6.7. The enzyme shows a high specific Mg2+-dependence, with apparent Km values of 3.0 μM for PEA and 11.4 μM for PCho. These results provide a novel mechanism for the generation of Pi in mineralizing cells from PEA and PCho. PMID:15175005

  5. Return-to-activity after anatomical reconstruction of acute high-grade acromioclavicular separation.

    Science.gov (United States)

    Saier, T; Plath, J E; Beitzel, K; Minzlaff, P; Feucht, J M; Reuter, S; Martetschläger, F; Imhoff, Andreas B; Aboalata, M; Braun, S

    2016-04-02

    To evaluate return-to-activity (RtA) after anatomical reconstruction of acute high-grade acromioclavicular joint (ACJ) separation. A total of 42 patients with anatomical reconstruction of acute high-grade ACJ-separation (Rockwood Type V) were surveyed to determine RtA at a mean 31 months follow-up (f-u). Sports disciplines, intensity, level of competition, participation in overhead and/or contact sports, as well as activity scales (DASH-Sport-Module, Tegner Activity Scale) were evaluated. Functional outcome evaluation included Constant score and QuickDASH. All patients (42/42) participated in sporting activities at f-u. Neither participation in overhead/contact sports, nor level of activity declined significantly (n.s.). 62 % (n = 26) of patients reported subjective sports specific ACJ integrity to be at least the same as prior to the trauma. Sporting intensity (hours/week: 7.3 h to 5.4 h, p = .004) and level of competition (p = .02) were reduced. If activity changed, in 50 % other reasons but clinical symptoms/impairment were named for modified behavior. QuickDASH (mean 6, range 0-54, SD 11) and DASH-Sport-Module (mean 6, range 0-56, SD 13) revealed only minor disabilities at f-u. Over time Constant score improved significant to an excellent score (mean 94, range 86-100, SD 4; p < .001). Functional outcome was not correlated with RtA (n.s.). All patients participated in sporting activities after anatomical reconstruction of high-grade (Rockwood Type V) ACJ-separation. With a high functional outcome there was no significant change in activity level (Tegner) and participation in overhead and/or contact sports observed. There was no correlation between functional outcome and RtA. Limiting, there were alterations in time spent for sporting activities and level of competition observed. But in 50 % those were not related to ACJ symptoms/impairment. Unrelated to successful re-established integrity and function of the ACJ it should be considered that

  6. Progress in the development of active heat sink for high-power laser diodes

    Science.gov (United States)

    Vetrovec, John; Feeler, Ryan; Bonham, Steve

    2010-02-01

    We report on the development of a novel active heat sink for high-power laser diodes offering unparalleled capacity in high-heat flux handling and temperature control. The heat sink receives diode waste heat at high flux and transfers it at reduced flux to environment, coolant fluid, heat pipe, or structure. Thermal conductance of the heat sink is electronically adjustable, allowing for precise control of diode temperature and the output light wavelength. When pumping solid-state lasers, diode wavelength can be precisely tuned to the absorption features of the laser gain medium. This paper presents the AHS concept, scaling laws, model predictions, and data from initial testing.

  7. Optimized Laser Thermal Annealing on Germanium for High Dopant Activation and Low Leakage Current

    DEFF Research Database (Denmark)

    Shayesteh, Maryam; O' Connell, Dan; Gity, Farzan

    2014-01-01

    In this paper, state-of-the-art laser thermal annealing is used to fabricate Ge diodes. We compared the effect of laser thermal annealing (LTA) and rapid thermal annealing (RTA) on dopant activation and electrical properties of phosphorus and Arsenic-doped n +/p junctions. Using LTA, high carrier...... implant conditions. On the other hand, RTA revealed very high I on/I off ratio ∼ 107 and n ∼ 1, at the cost of high dopant diffusion and lower carrier concentrations which would degrade scalability and access resistance....

  8. Synchronous fire activity in the tropical high Andes: an indication of regional climate forcing.

    Science.gov (United States)

    Román-Cuesta, R M; Carmona-Moreno, C; Lizcano, G; New, M; Silman, M; Knoke, T; Malhi, Y; Oliveras, I; Asbjornsen, H; Vuille, M

    2014-06-01

    Global climate models suggest enhanced warming of the tropical mid and upper troposphere, with larger temperature rise rates at higher elevations. Changes in fire activity are amongst the most significant ecological consequences of rising temperatures and changing hydrological properties in mountainous ecosystems, and there is a global evidence of increased fire activity with elevation. Whilst fire research has become popular in the tropical lowlands, much less is known of the tropical high Andean region (>2000 masl, from Colombia to Bolivia). This study examines fire trends in the high Andes for three ecosystems, the Puna, the Paramo and the Yungas, for the period 1982-2006. We pose three questions: (i) is there an increased fire response with elevation? (ii) does the El Niño- Southern Oscillation control fire activity in this region? (iii) are the observed fire trends human driven (e.g., human practices and their effects on fuel build-up) or climate driven? We did not find evidence of increased fire activity with elevation but, instead, a quasicyclic and synchronous fire response in Ecuador, Peru and Bolivia, suggesting the influence of high-frequency climate forcing on fire responses on a subcontinental scale, in the high Andes. ENSO variability did not show a significant relation to fire activity for these three countries, partly because ENSO variability did not significantly relate to precipitation extremes, although it strongly did to temperature extremes. Whilst ENSO did not individually lead the observed regional fire trends, our results suggest a climate influence on fire activity, mainly through a sawtooth pattern of precipitation (increased rainfall before fire-peak seasons (t-1) followed by drought spells and unusual low temperatures (t0), which is particularly common where fire is carried by low fuel loads (e.g., grasslands and fine fuel). This climatic sawtooth appeared as the main driver of fire trends, above local human influences and fuel build

  9. High content analysis of phagocytic activity and cell morphology with PuntoMorph.

    Science.gov (United States)

    Al-Ali, Hassan; Gao, Han; Dalby-Hansen, Camilla; Peters, Vanessa Ann; Shi, Yan; Brambilla, Roberta

    2017-11-01

    Phagocytosis is essential for maintenance of normal homeostasis and healthy tissue. As such, it is a therapeutic target for a wide range of clinical applications. The development of phenotypic screens targeting phagocytosis has lagged behind, however, due to the difficulties associated with image-based quantification of phagocytic activity. We present a robust algorithm and cell-based assay system for high content analysis of phagocytic activity. The method utilizes fluorescently labeled beads as a phagocytic substrate with defined physical properties. The algorithm employs statistical modeling to determine the mean fluorescence of individual beads within each image, and uses the information to conduct an accurate count of phagocytosed beads. In addition, the algorithm conducts detailed and sophisticated analysis of cellular morphology, making it a standalone tool for high content screening. We tested our assay system using microglial cultures. Our results recapitulated previous findings on the effects of microglial stimulation on cell morphology and phagocytic activity. Moreover, our cell-level analysis revealed that the two phenotypes associated with microglial activation, specifically cell body hypertrophy and increased phagocytic activity, are not highly correlated. This novel finding suggests the two phenotypes may be under the control of distinct signaling pathways. We demonstrate that our assay system outperforms preexisting methods for quantifying phagocytic activity in multiple dimensions including speed, accuracy, and resolution. We provide a framework to facilitate the development of high content assays suitable for drug screening. For convenience, we implemented our algorithm in a standalone software package, PuntoMorph. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Highly stable plasminogen activator inhibitor type one (VLHL PAI-1) protects fibrin clots from tissue plasminogen activator-mediated fibrinolysis.

    Science.gov (United States)

    Jankun, Jerzy; Aleem, Ansari M; Selman, Steven H; Skrzypczak-Jankun, Ewa; Lysiak-Szydlowska, Wieslawa; Grafos, Nicholas; Fryer, Hugh J L; Greenfield, Robert S

    2007-11-01

    Plasminogen activator inhibitor-1 (PAI-1) is the major specific inhibitor of tissue-type plasminogen activator (tPA) which mediates fibrin clot lysis through activation of plasminogen. Wild-type-PAI-1 (wPAI-1) is rapidly converted to the latent form (half-life of approximately 2 h) and loses its ability to inhibit tPA. We developed a very long half-life PAI-1 (VLHL PAI-1), a recombinant protein with a half-life >700 h compared with wPAI-1. In this study, VLHL PAI-1 was assessed for its ability to inhibit clot lysis in vitro. Clot formation was initiated in normal plasma supplemented with tPA by the addition of either tissue factor or human recombinant FVIIa. Clot lysis time, monitored turbidimetrically in a microtiter plate reader, was determined at various concentrations of wPAI-1 and VLHL PAI-1. Both wPAI-1 and VLHL PAI-1 caused a significant increase in clot lysis time, although the latter was somewhat less effective at lower concentrations. The VLHL PAI-1, but not wPAI-1, maintained its anti-fibrinolytic activity after preincubation overnight at 37 degrees. These studies demonstrate that VLHL PAI-1 is an effective inhibitor of fibrin clot degradation. Due to the high stability of VLHL PAI-1 compared with wPAI-1, this novel inhibitor of tPA-mediated fibrinolysis may have therapeutic applications for treating surgical and trauma patients when used directly or in conjunction with the procoagulant recombinant FVIIa.

  11. High-fat feeding induces angiogenesis in skeletal muscle and activates angiogenic pathways in capillaries.

    Science.gov (United States)

    Silvennoinen, Mika; Rinnankoski-Tuikka, Rita; Vuento, Mikael; Hulmi, Juha J; Torvinen, Sira; Lehti, Maarit; Kivelä, Riikka; Kainulainen, Heikki

    2013-04-01

    High-fat diet (HFD) increases fatty acid oxidation in skeletal muscles. We hypothesized that this leads to increased oxygen demand and thus to increased capillarization. We determined the effects of high-fat diet on capillarization and angiogenic factors in skeletal muscles of mice that were either active or sedentary. Fifty-eight C57BL/6 J mice were divided into four groups: low-fat diet sedentary (LFS), low-fat diet active (LFA), high-fat diet sedentary (HFS), and high-fat diet active (HFA). The mice in active groups were housed in cages with running wheels and the sedentary mice were housed in similar cages without running wheels. After 19 weeks HFS, LFA and HFA had higher capillary density and capillary-to-fiber-ratio in quadriceps femoris muscles than LFS. Capillarization was similar in HFS and HFA. To reveal possible mechanisms of HFD induced angiogenesis, we measured protein and mRNA levels of angiogenic factors VEGF-A, HIF-1α, PGC-1α and ERRα. VEGF-A protein levels were higher in muscles of HFS, LFA and HFA compared to LFS. However, no significant differences were observed between HFA and HFS. Protein levels of HIF-1α, PGC-1α, and ERRα were similar in all groups. However, the mRNA expression of HIF-1α and VEGF-A was up-regulated in capillaries but not in muscle fibers of HFS. The sedentary and active mice groups had similar mRNA expression levels of angiogenesis regulators studied. We conclude that high-fat feeding induces angiogenesis in skeletal muscle and up-regulates the gene expression of HIF-1α and VEGF-A in capillaries.

  12. Effects of human activities on the ecological processes of river biofilms in a highly urbanized river

    Science.gov (United States)

    Hung, R.; Li, M.

    2013-12-01

    Many anthropogenic disturbances and their effects of aquatic ecosystem are difficult to quantify in urbanized rivers. In past, specific taxa analysis of community structure was a common approach in river health monitoring studies. However, it is still difficult to understand stream ecosystem integrity without considering ecosystem processes. The complex species composition and metabolism of a river biofilm have the capacity to interact and/or modulate their surrounding environment. Because of their short life cycles, species richness, and worldwide distribution, structure and function of river biofilm communities are sensitive to change in environmental conditions. Therefore, biofilms are widely used as early warning systems of water pollution for water quality monitoring studies. In this study, we used river biofilms as a bioindicator by examining their extracellular enzyme activities and photosynthesis efficiency to understand human activities on the ecological processes of river ecosystem in a highly urbanized river. We sampled four sites along the Keelung River, Taiwan, based on different intensities of anthropogenic disturbances including water pollution index, population densities, land use types and types of stream habitats. Two study sites are heavily influenced by human activities and the others are not. The activities of extracellular enzymes within the biofilm play an important function for organic matter decomposition and nutrient cycling. We measured seven extracellular enzyme activities (β-d-glucosidase, phosphatase, leucine-aminopeptidase, sulfatase, peroxidase, polyphenol oxidase, and esterase) to examine specific enzyme activity changes at four study sites monthly. In addition, relative proportion of each extracellular enzyme activity on total enzyme activities was calculated in order to examine the relationship between functional biofilm profiles and different urban intensities. Among four study sites, leucine-aminopeptidase and esterase

  13. Selective enrichment and production of highly urease active bacteria by non-sterile (open) chemostat culture.

    Science.gov (United States)

    Cheng, Liang; Cord-Ruwisch, Ralf

    2013-10-01

    In general, bioprocesses can be subdivided into naturally occurring processes, not requiring sterility (e.g., beer brewing, wine making, lactic acid fermentation, or biogas digestion) and other processes (e.g., the production of enzymes and antibiotics) that typically require a high level of sterility to avoid contaminant microbes overgrowing the production strain. The current paper describes the sustainable, non-sterile production of an industrial enzyme using activated sludge as inoculum. By using selective conditions (high pH, high ammonia concentration, and presence of urea) for the target bacterium, highly active ureolytic bacteria, physiologically resembling Sporosarcina pasteurii were reproducibly enriched and then continuously produced via chemostat operation of the bioreactor. When using a pH of 10 and about 0.2 M urea in a yeast extract-based medium, ureolytic bacteria developed under aerobic chemostat operation at hydraulic retention times of about 10 h with urease levels of about 60 μmol min⁻¹ ml⁻¹ culture. For cost minimization at an industrial scale the costly protein-rich yeast extract medium could be replaced by commercial milk powder or by lysed activated sludge. Glutamate, molasses, or glucose-based media did not result in the enrichment of ureolytic bacteria by the chemostat. The concentration of intracellular urease was sufficiently high such that the produced raw effluent from the reactor could be used directly for biocementation in the field.

  14. Ascaroside activity in Caenorhabditis elegans is highly dependent on chemical structure.

    Science.gov (United States)

    Hollister, Kyle A; Conner, Elizabeth S; Zhang, Xinxing; Spell, Mark; Bernard, Gary M; Patel, Pratik; de Carvalho, Ana Carolina G V; Butcher, Rebecca A; Ragains, Justin R

    2013-09-15

    The nematode Caenorhabditis elegans secretes ascarosides, structurally diverse derivatives of the 3,6-dideoxysugar ascarylose, and uses them in chemical communication. At high population densities, specific ascarosides, which are together known as the dauer pheromone, trigger entry into the stress-resistant dauer larval stage. In order to study the structure-activity relationships for the ascarosides, we synthesized a panel of ascarosides and tested them for dauer-inducing activity. This panel includes a number of natural ascarosides that were detected in crude pheromone extract, but as yet have no assigned function, as well as many unnatural ascaroside derivatives. Most of these ascarosides, some of which have significant structural similarity to the natural dauer pheromone components, have very little dauer-inducing activity. Our results provide a primer to ascaroside structure-activity relationships and suggest that slight modifications to ascaroside structure dramatically influence binding to the relevant G protein-coupled receptors that control dauer formation.

  15. Effect of high-fructose and high-fat diets on pulmonary sensitivity, motor activity, and body composition of brown Norway rats exposed to ozone

    Data.gov (United States)

    U.S. Environmental Protection Agency — pulmonary parameters, BALF biomarkers, body composition, motor activity data collected from rats exposed to ozone after high fructose or high fat diets. This dataset...

  16. Associations of Low- and High-Intensity Light Activity with Cardiometabolic Biomarkers.

    Science.gov (United States)

    Howard, Bethany; Winkler, Elisabeth A H; Sethi, Parneet; Carson, Valerie; Ridgers, Nicola D; Salmon, J O; Healy, Genevieve N; Owen, Neville; Dunstan, David W

    2015-10-01

    Light-intensity physical activity (LIPA) accounts for much of adults' waking hours (≈40%) and substantially contributes to overall daily energy expenditure. Encompassing activity behaviors of low intensity (standing with little movement) to those of higher intensity (slow walking), LIPA is ubiquitous, yet little is known about how associations with health may vary depending on its intensity. We examined the associations of objectively assessed LIPA (categorized as either low LIPA [LLPA] or high LIPA [HLPA]) and moderate- to vigorous-intensity activity with cardiometabolic risk biomarkers. Cardiometabolic biomarkers were measured in 4614 US adults (47 ± 17 yr) who participated in the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey cycles. Multiple linear regression analyses examined the associations of three accelerometer-derived physical activity (SD increment per day) intensity categories (LLPA, 100-761 counts per minute; HLPA, 762-1951 counts per minute; moderate-intensity physical activity [MPA], 1952-5724 counts per minute; vigorous-intensity physical activity [VPA], ≥5725 counts per minute) with cardiometabolic biomarkers, adjusting for potential sociodemographic, behavioral, and medical confounders. All intensities of physical activity were beneficially associated with waist circumference, C-reactive protein, triglycerides, fasting insulin, β-cell function, and insulin sensitivity (P activity intensities showed significant associations with systolic blood pressure (LLPA), body mass index, HDL cholesterol, fasting glucose, and 2-h plasma glucose (HLPA, MPA, and VPA). Generally, effect size increased with intensity of physical activity. Overall, further adjustment for waist circumference attenuated associations with MPA and VPA to a greater extent than associations with LLPA and HLPA. The cross-sectional findings provide novel evidence for the potential benefits of increasing both LLPA and HLPA. They further reinforce the

  17. Computational model explains high activity and rapid cycling of Rho GTPases within protein complexes.

    Directory of Open Access Journals (Sweden)

    Andrew B Goryachev

    2006-12-01

    Full Text Available Formation of multiprotein complexes on cellular membranes is critically dependent on the cyclic activation of small GTPases. FRAP-based analyses demonstrate that within protein complexes, some small GTPases cycle nearly three orders of magnitude faster than they would spontaneously cycle in vitro. At the same time, experiments report concomitant excess of the activated, GTP-bound form of GTPases over their inactive form. Intuitively, high activity and rapid turnover are contradictory requirements. How the cells manage to maximize both remains poorly understood. Here, using GTPases of the Rab and Rho families as a prototype, we introduce a computational model of the GTPase cycle. We quantitatively investigate several plausible layouts of the cycling control module that consist of GEFs, GAPs, and GTPase effectors. We explain the existing experimental data and predict how the cycling of GTPases is controlled by the regulatory proteins in vivo. Our model explains distinct and separable roles that the activating GEFs and deactivating GAPs play in the GTPase cycling control. While the activity of GTPase is mainly defined by GEF, the turnover rate is a sole function of GAP. Maximization of the GTPase activity and turnover rate places conflicting requirements on the concentration of GAP. Therefore, to achieve a high activity and turnover rate at once, cells must carefully maintain concentrations of GEFs and GAPs within the optimal range. The values of these optimal concentrations indicate that efficient cycling can be achieved only within dense protein complexes typically assembled on the membrane surfaces. We show that the concentration requirement for GEF can be dramatically reduced by a GEF-activating GTPase effector that can also significantly boost the cycling efficiency. Interestingly, we find that the cycling regimes are only weakly dependent on the concentration of GTPase itself.

  18. Porcine pancreatic lipase related protein 2 has high triglyceride lipase activity in the absence of colipase.

    Science.gov (United States)

    Xiao, Xunjun; Ross, Leah E; Sevilla, Wednesday A; Wang, Yan; Lowe, Mark E

    2013-09-01

    Efficient dietary fat digestion is essential for newborns who consume more dietary fat per body weight than at any other time of life. In many mammalian newborns, pancreatic lipase related protein 2 (PLRP2) is the predominant duodenal lipase. Pigs may be an exception since PLRP2 expression has been documented in the intestine but not in the pancreas. Because of the differences in tissue-specific expression, we hypothesized that the kinetic properties of porcine PLRP2 would differ from those of other mammals. To characterize its properties, recombinant porcine PLRP2 was expressed in HEK293T cells and purified to homogeneity. Porcine PLRP2 had activity against tributyrin, trioctanoin and triolein. The activity was not inhibited by bile salts and colipase, which is required for the activity of pancreatic triglyceride lipase (PTL), minimally stimulated PLRP2 activity. Similar to PLRP2 from other species, PLRP2 from pigs had activity against galactolipids and phospholipids. Importantly, porcine PLRP2 hydrolyzed a variety of dietary substrates including pasteurized human mother's milk and infant formula and its activity was comparable to that of PTL. In conclusion, porcine PLRP2 has broad substrate specificity and has high triglyceride lipase activity even in the absence of colipase. The data suggest that porcine PLRP2 would be a suitable lipase for inclusion in recombinant preparations for pancreatic enzyme replacement therapy.

  19. Spatiotemporal dynamics of word retrieval in speech production revealed by cortical high-frequency band activity.

    Science.gov (United States)

    Riès, Stephanie K; Dhillon, Rummit K; Clarke, Alex; King-Stephens, David; Laxer, Kenneth D; Weber, Peter B; Kuperman, Rachel A; Auguste, Kurtis I; Brunner, Peter; Schalk, Gerwin; Lin, Jack J; Parvizi, Josef; Crone, Nathan E; Dronkers, Nina F; Knight, Robert T

    2017-06-06

    Word retrieval is core to language production and relies on complementary processes: the rapid activation of lexical and conceptual representations and word selection, which chooses the correct word among semantically related competitors. Lexical and conceptual activation is measured by semantic priming. In contrast, word selection is indexed by semantic interference and is hampered in semantically homogeneous (HOM) contexts. We examined the spatiotemporal dynamics of these complementary processes in a picture naming task with blocks of semantically heterogeneous (HET) or HOM stimuli. We used electrocorticography data obtained from frontal and temporal cortices, permitting detailed spatiotemporal analysis of word retrieval processes. A semantic interference effect was observed with naming latencies longer in HOM versus HET blocks. Cortical response strength as indexed by high-frequency band (HFB) activity (70-150 Hz) amplitude revealed effects linked to lexical-semantic activation and word selection observed in widespread regions of the cortical mantle. Depending on the subsecond timing and cortical region, HFB indexed semantic interference (i.e., more activity in HOM than HET blocks) or semantic priming effects (i.e., more activity in HET than HOM blocks). These effects overlapped in time and space in the left posterior inferior temporal gyrus and the left prefrontal cortex. The data do not support a modular view of word retrieval in speech production but rather support substantial overlap of lexical-semantic activation and word selection mechanisms in the brain.

  20. Selective anticancer activity of a hexapeptide with sequence homology to a non-kinase domain of Cyclin Dependent Kinase 4

    Directory of Open Access Journals (Sweden)

    Agarwala Usha

    2011-06-01

    Full Text Available Abstract Background Cyclin-dependent kinases 2, 4 and 6 (Cdk2, Cdk4, Cdk6 are closely structurally homologous proteins which are classically understood to control the transition from the G1 to the S-phases of the cell cycle by combining with their appropriate cyclin D or cyclin E partners to form kinase-active holoenzymes. Deregulation of Cdk4 is widespread in human cancer, CDK4 gene knockout is highly protective against chemical and oncogene-mediated epithelial carcinogenesis, despite the continued presence of CDK2 and CDK6; and overexpresssion of Cdk4 promotes skin carcinogenesis. Surprisingly, however, Cdk4 kinase inhibitors have not yet fulfilled their expectation as 'blockbuster' anticancer agents. Resistance to inhibition of Cdk4 kinase in some cases could potentially be due to a non-kinase activity, as recently reported with epidermal growth factor receptor. Results A search for a potential functional site of non-kinase activity present in Cdk4 but not Cdk2 or Cdk6 revealed a previously-unidentified loop on the outside of the C'-terminal non-kinase domain of Cdk4, containing a central amino-acid sequence, Pro-Arg-Gly-Pro-Arg-Pro (PRGPRP. An isolated hexapeptide with this sequence and its cyclic amphiphilic congeners are selectively lethal at high doses to a wide range of human cancer cell lines whilst sparing normal diploid keratinocytes and fibroblasts. Treated cancer cells do not exhibit the wide variability of dose response typically seen with other anticancer agents. Cancer cell killing by PRGPRP, in a cyclic amphiphilic cassette, requires cells to be in cycle but does not perturb cell cycle distribution and is accompanied by altered relative Cdk4/Cdk1 expression and selective decrease in ATP levels. Morphological features of apoptosis are absent and cancer cell death does not appear to involve autophagy. Conclusion These findings suggest a potential new paradigm for the development of broad-spectrum cancer specific therapeutics with

  1. Rapid ester biosynthesis screening reveals a high activity alcohol-O-acyltransferase (AATase) from tomato fruit.

    Science.gov (United States)

    Lin, Jyun-Liang; Zhu, Jie; Wheeldon, Ian

    2016-05-01

    Ethyl and acetate esters are naturally produced in various yeasts, plants, and bacteria. The biosynthetic pathways that produce these esters share a common reaction step, the condensation of acetyl/acyl-CoA with an alcohol by alcohol-O-acetyl/acyltransferase (AATase). Recent metabolic engineering efforts exploit AATase activity to produce fatty acid ethyl esters as potential diesel fuel replacements as well as short- and medium-chain volatile esters as fragrance and flavor compounds. These efforts have been limited by the lack of a rapid screen to quantify ester biosynthesis. Enzyme engineering efforts have also been limited by the lack of a high throughput screen for AATase activity. Here, we developed a high throughput assay for AATase activity and used this assay to discover a high activity AATase from tomato fruit, Solanum lycopersicum (Atf-S.l). Atf1-S.l exhibited broad specificity towards acyl-CoAs with chain length from C4 to C10 and was specific towards 1-pentanol. The AATase screen also revealed new acyl-CoA substrate specificities for Atf1, Atf2, Eht1, and Eeb1 from Saccharomyces cerevisiae, and Atf-C.m from melon fruit, Cucumis melo, thus increasing the pool of characterized AATases that can be used in ester biosynthesis of ester-based fragrance and flavor compounds as well as fatty acid ethyl ester biofuels.

  2. Regrouping: organized activity involvement and social adjustment across the transition to high school.

    Science.gov (United States)

    Bohnert, Amy M; Aikins, Julie Wargo; Arola, Nicole T

    2013-01-01

    Although organized activities (OAs) have been established as important contexts of development, limited work has examined the role of OAs across the high school transition in buffering adolescents' social adjustment by providing opportunities for visibility and peer affiliation. The transition to high school is characterized by numerous changes and OAs may provide an important setting for establishing and maintaining peer relationships during this tumultuous time. This study included 151 8th grade U.S. students (58% male) who were assessed across the transition to high school (spring of 8th and 9th grade). Continuous involvement in academic activities across the transition and becoming involved (i.e., initiation) in community/service activities following the transition was associated with fewer depressive symptoms in the spring of 9th grade. Continuous involvement in sports and initiation of academic activities was associated with having more friendships. In addition, links between OAs and loneliness were only evident among females. There appear to be significant social benefits for OA involvement.

  3. The active methanotrophic community in a wetland from the High Arctic.

    Science.gov (United States)

    Graef, Christiane; Hestnes, Anne Grethe; Svenning, Mette Marianne; Frenzel, Peter

    2011-08-01

    The dominant terminal process of carbon mineralization in most freshwater wetlands is methanogenesis. With methane being an important greenhouse gas, the predicted warming of the Arctic may provide a positive feedback. However, the amount of methane released to the atmosphere may be controlled by the activity of methane-oxidizing bacteria (methanotrophs) living in the oxic surface layer of wetlands. Previously, methanotrophs have been isolated and identified by genetic profiling in High Arctic wetlands showing the presence of only a few genotypes. Two isolates from Solvatnet (Ny-Ålesund, Spitsbergen; 79°N) are available: Methylobacter tundripaludum (type I) and Methylocystis rosea (type II), raising the question whether the low diversity is a cultivation effect. We have revisited Solvatnet applying stable isotope probing (SIP) with (13) C-labelled methane. 16S rRNA profiling revealed active type I methanotrophs including M. tundripaludum, while no active type II methanotrophs were identified. These results indicate that the extant M. tundripaludum is an active methane oxidizer at its locus typicus; furthermore, Methylobacter seems to be the dominant active genus. Diversity of methanotrophs was low as compared, e.g. to wetland rice fields in the Mediterranean. This low diversity suggests a high vulnerability of Arctic methanotroph communities, which deserves more attention.

  4. Recent and episodic volcanic and glacial activity on Mars revealed by the High Resolution Stereo Camera.

    Science.gov (United States)

    Neukum, G; Jaumann, R; Hoffmann, H; Hauber, E; Head, J W; Basilevsky, A T; Ivanov, B A; Werner, S C; van Gasselt, S; Murray, J B; McCord, T

    2004-12-23

    The large-area coverage at a resolution of 10-20 metres per pixel in colour and three dimensions with the High Resolution Stereo Camera Experiment on the European Space Agency Mars Express Mission has made it possible to study the time-stratigraphic relationships of volcanic and glacial structures in unprecedented detail and give insight into the geological evolution of Mars. Here we show that calderas on five major volcanoes on Mars have undergone repeated activation and resurfacing during the last 20 per cent of martian history, with phases of activity as young as two million years, suggesting that the volcanoes are potentially still active today. Glacial deposits at the base of the Olympus Mons escarpment show evidence for repeated phases of activity as recently as about four million years ago. Morphological evidence is found that snow and ice deposition on the Olympus construct at elevations of more than 7,000 metres led to episodes of glacial activity at this height. Even now, water ice protected by an insulating layer of dust may be present at high altitudes on Olympus Mons.

  5. Passive and Active Protective Clothing against High-Power Laser Radiation

    Science.gov (United States)

    Hennigs, C.; Hustedt, M.; Kaierle, S.; Wenzel, D.; Markstein, S.; Hutter, A.

    The main objective of the work described in this paper was the development of passive and active protective clothing for the protection of the human skin against accidental laser irradiation and of active protective curtains. Here, the passive systems consist of functional multi-layer textiles, providing a high level of passive laser resistance. In addition, the active functional multi-layer textiles incorporate sensors that detect laser exposure and are, by means of a safety control, able to deactivate the laser beam automatically.Due to the lack of regulations for testing and qualifying textiles to be used as laser PPE, test methods were defined and validated. Additionally, corresponding testing set-ups were developed.Finally, the gap with respect to standardization was bridged by the definition of a test procedure and the requirements with respect to laser PPE.The developments were demonstrated by a set of tailored functional passive and active laser-protective clothing prototypes (gloves, jackets, aprons, trousers) and active curtains as well as by a prototype testing rig, providing the possibility to perform the specified low-power and high-power textile test procedure.

  6. Metabolic engineering of Escherichia coli cell factory for highly active xanthine dehydrogenase production.

    Science.gov (United States)

    Wang, Cheng-Hua; Zhang, Chong; Xing, Xin-Hui

    2017-05-31

    The aim of this work was to demonstrate the first proof-of-concept for the use of ab initio-aided assembly strategy intensifying in vivo biosynthesis process to construct Escherichia coli cell factory overproducing highly active xanthine dehydrogenase (XDH). Three global regulator (IscS, TusA and NarJ) and four chaperone proteins (DsbA, DsbB, NifS and XdhC) were overexpressed to aid the formation and ordered assembly of three redox center cofactors of Rhodobacter capsulatus XDH in E. coli. The NifS, IscS and DsbB enhanced the specific activity of RcXDH by 30%, 94% and 49%, respectively. The combinatorial expression of NarJ and IscS synergistically increased the specific activity by 129% and enhanced the total enzyme activity by a remarkable 3.9-fold. The crude enzyme showed nearly the same coupling efficiency of electron transfer and product formation as previously purified XDHs, indicating an integrity and efficient assembly of highly active XDH. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Autophagic flux is highly active in early mitosis and differentially regulated throughout the cell cycle

    Science.gov (United States)

    Li, Zhiyuan; Ji, Xinmiao; Wang, Dongmei; Liu, Juanjuan; Zhang, Xin

    2016-01-01

    Mitosis is a fast process that involves dramatic cellular remodeling and has a high energy demand. Whether autophagy is active or inactive during the early stages of mitosis in a naturally dividing cell is still debated. Here we aimed to use multiple assays to resolve this apparent discrepancy. Although the LC3 puncta number was reduced in mitosis, the four different cell lines we tested all have active autophagic flux in both interphase and mitosis. In addition, the autophagic flux was highly active in nocodazole-induced, double-thymidine synchronization released as well as naturally occurring mitosis in HeLa cells. Multiple autophagy proteins are upregulated in mitosis and the increased Beclin-1 level likely contributes to the active autophagic flux in early mitosis. It is interesting that although the autophagic flux is active throughout the cell cycle, early mitosis and S phase have relatively higher autophagic flux than G1 and late G2 phases, which might be helpful to degrade the damaged organelles and provide energy during S phase and mitosis. PMID:27213594

  8. Performance at high temperature of alkali-activated slag pastes produced with silica fume and rice husk ash based activators

    Directory of Open Access Journals (Sweden)

    Bernal, S. A.

    2015-06-01

    Full Text Available This study assessed the mechanical properties, and structural changes induced by high temperature exposure, of alkali-silicate activated slag cements produced with sodium silicates derived from silica fume (SF and rice husk ash (RHA. Similar reaction products were identified, independent of the type of silicate used, but with subtle differences in the composition of the C-S-H gels, leading to different strength losses after elevated temperature exposure. Cements produced with the alternative activators developed higher compressive strengths than those produced with commercial silicate. All samples retained strengths of more than 50 MPa after exposure to 600 °C, however, after exposure to 800 °C only the specimens produced with the RHA-based activator retained measurable strength. This study elucidated that silicate-activated slag binders, either activated with commercial silicate solutions or with sodium silicates based on SF or RHA, are stable up to 600 °C.Este estudio evaluó las propiedades mecánicas, y cambios estructurales inducidos por exposición a temperaturas elevadas, de cementos de escoria activada alcalinamente producidos con silicatos sódicos derivados de humo de sílice (SF y ceniza de cascarilla de arroz (RHA. Se identificaron productos de reacción similares, independiente del tipo de silicato utilizado, pero con diferencias menores en la composición de las geles C-S-H, lo cual indujo diferentes pérdidas de resistencia posterior a exposición a temperaturas elevadas. Los cementantes producidos con los activadores alternativos desarrollaron resistencias a la compresión más altas que aquellos producidos con silicato comercial. Todas las muestras retuvieron resistencias de más de 50 MPa posterior a la exposición a 600 °C, sin embargo, posterior a la exposición a 800 °C únicamente muestras producidas con activadores de RHA retuvieron resistencias medibles. Este estudio elucidó que cementantes de escoria activada con

  9. O+ heating associated with strong wave activity in the high altitude cusp and mantle

    Directory of Open Access Journals (Sweden)

    G. Stenberg

    2011-05-01

    Full Text Available We use the Cluster spacecraft to study three events with intense waves and energetic oxygen ions (O+ in the high altitude cusp and mantle. The ion energies considered are of the order 1000 eV and higher, observed above an altitude of 8 earth radii together with high wave power at the O+ gyrofrequency. We show that heating by waves can explain the observed high perpendicular energy of O+ ions, using a simple gyroresonance model and 25–45% of the observed wave spectral density at the gyrofrequency. This is in contrast to a recently published study where the wave intensity was too low to explain the observed high altitude ion energies. Long lasting cases (>10 min of high perpendicular-to-parallel temperature ratios are sometimes associated with low wave activity, suggesting that high perpendicular-to-parallel temperature ratio is not a good indicator of local heating. Using multiple spacecraft, we show that the regions of enhanced wave activity are at least one order of magnitude larger than the gyroradius of the heated ions.

  10. Pancreatic lipase activity in overnight effluent predicts high transport status in peritoneal dialysis patients.

    Science.gov (United States)

    Idei, Mayumi; Tabe, Yoko; Hamada, Chieko; Miyake, Kazunori; Takemura, Hiroyuki; Io, Hiroaki; Wakita, Mitsuru; Horii, Takashi; Tomino, Yasuhiko; Ohsaka, Akimichi; Miida, Takashi

    2016-11-01

    Long-term peritoneal dialysis (PD) causes peritoneal morphological and functional changes, resulting in high transport status featuring increased peritoneal permeability. High transport status is diagnosed by peritoneal equilibration test (PET), a reliable but time-consuming method. We identifed a reliable biomarker in peritoneal effluent to predict high transport status in PD patients. We collected peritoneal effluent and serum from 33 PD patients and measured common laboratory test parameters. High transport status was determined by PET if the dialysate/plasma ratio of creatinine at 4h dwell (D/P Cr 4h) was ≥0.81. There were significant correlations between D/P Cr 4h and some laboratory parameters in overnight effluent (pancreatic lipase activity, r=0.65, povernight effluent was identified as an independent predictor of high transport status even after adjusting for age, PD duration, and glomerular filtration rate [OR=1.43 (95% CI: 1.11-1.83), p=0.005]. The pancreatic lipase activity in overnight effluent is an independent predictor of high transport status in PD patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Asphalt-derived high surface area activated porous carbons for carbon dioxide capture.

    Science.gov (United States)

    Jalilov, Almaz S; Ruan, Gedeng; Hwang, Chih-Chau; Schipper, Desmond E; Tour, Josiah J; Li, Yilun; Fei, Huilong; Samuel, Errol L G; Tour, James M

    2015-01-21

    Research activity toward the development of new sorbents for carbon dioxide (CO2) capture have been increasing quickly. Despite the variety of existing materials with high surface areas and high CO2 uptake performances, the cost of the materials remains a dominant factor in slowing their industrial applications. Here we report preparation and CO2 uptake performance of microporous carbon materials synthesized from asphalt, a very inexpensive carbon source. Carbonization of asphalt with potassium hydroxide (KOH) at high temperatures (>600 °C) yields porous carbon materials (A-PC) with high surface areas of up to 2780 m(2) g(-1) and high CO2 uptake performance of 21 mmol g(-1) or 93 wt % at 30 bar and 25 °C. Furthermore, nitrogen doping and reduction with hydrogen yields active N-doped materials (A-NPC and A-rNPC) containing up to 9.3% nitrogen, making them nucleophilic porous carbons with further increase in the Brunauer-Emmett-Teller (BET) surface areas up to 2860 m(2) g(-1) for A-NPC and CO2 uptake to 26 mmol g(-1) or 114 wt % at 30 bar and 25 °C for A-rNPC. This is the highest reported CO2 uptake among the family of the activated porous carbonaceous materials. Thus, the porous carbon materials from asphalt have excellent properties for reversibly capturing CO2 at the well-head during the extraction of natural gas, a naturally occurring high pressure source of CO2. Through a pressure swing sorption process, when the asphalt-derived material is returned to 1 bar, the CO2 is released, thereby rendering a reversible capture medium that is highly efficient yet very inexpensive.

  12. Increased Low- and High-Frequency Oscillatory Activity in the Prefrontal Cortex of Fibromyalgia Patients

    Science.gov (United States)

    Lim, Manyoel; Kim, June Sic; Kim, Dajung J.; Chung, Chun Kee

    2016-01-01

    Recent human neuroimaging studies have suggested that fibromyalgia (FM), a chronic widespread pain disorder, exhibits altered thalamic structure and function. Since the thalamus has extensive reciprocal connection with the cortex, structural and functional thalamic alterations in FM might be linked to aberrant thalamocortical oscillation. This study investigated the presence of abnormal brain rhythmicity in low- and high-frequency bands during resting state in patients with FM and their relationship to clinical pain symptom. Spontaneous magnetoencephalography (MEG) activity was recorded in 18 females with FM and 18 age- and sex-matched healthy control (HC) subjects. The most remarkable finding was that FM patients had general increases in theta, beta and gamma power along with a slowing of the dominant alpha peak. Increased spectral powers in the theta-band were primarily localized to the left dorsolateral prefrontal (DLPFC) and orbitofrontal cortex (OFC). Beta and gamma over-activation were localized to insular, primary motor and primary and secondary somatosensory (S2) cortices, as well as the DLPFC and OFC. Furthermore, enhanced high-frequency oscillatory activities in the DLPFC and OFC were associated with higher affective pain scores in patients with FM. Our results demonstrate that FM patients feature enhanced low- and high-frequency oscillatory activity in the brain areas related to cognitive and emotional modulation of pain. Increased low- and high-frequency activity of the prefrontal cortex may contribute to persistent perception of pain in FM. Therapeutic intervention based on manipulating neural oscillation to restore normal thalamocortical rhythmicity may be beneficial to pain relief in FM. PMID:27014041

  13. Self-Related Health, Physical Activity and Complaints in Swedish High School Students

    Directory of Open Access Journals (Sweden)

    Marie Alricsson

    2006-01-01

    Full Text Available The aim of this investigation was to study self-related health, physical activity and level of exertion, as well as body complaints in Swedish high school students. A total of 993 high school students aged 16–19 years participated in the study. A questionnaire was completed at school and included questions about self-related health, physical activity behavior, type of physical activity/sport, intensity, duration, possible injuries or complaints, and absence from physical training at school, during the last 3 months. The results showed that 26% of the high school students participated in sports on a regular basis. Males reported significantly better health than females (p < 0.0005. A significantly higher number of females participated in physical activities at a lower level of effort (p < 0.0005 and a higher number of males trained at a higher level of effort (p < 0.005. Sixtyone percent reported body pain during the last 3 months, representing a higher number of females than males (p = 0.03. A higher number of females than males reported complaints from the back (p = 0.002, the knees (p = 0.015, the neck (p = 0.001, and the hip (p = 0.015. Females with body complaints reported poorer health than those without complaints. There was a correlation between poor self-related health and a lower level of physical effort (0.219; p < 0.001. The results showed that the prevalence of musculoskeletal symptoms was high in this population and demonstrated a certain association with self-related health. Therefore, it is important to make it easy for adolescents to perform physical activity at school and during their leisure time in order to prevent chronic diseases.

  14. The role of the catalysts with highly dispersed and isolated active sites in the selective oxidation of light hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    WANG Hongxuan; ZHAO Zhen

    2005-01-01

    This review summarizes the role of catalysts with highly dispersed and isolated active sites (active sites: supported atoms f≤0.5 % ) in the selective oxidation of light hydrocarbons, such as methane, ethane and propane, into oxygenatesand the epoxidation of olefins. The plausible structures of the highly dispersed and isolated active species, as well as their effects on the catalytic performances are discussed. The special physico-chemical properties and the functional mechanism of the catalysts with highly dispersed and isolated active sites, as well as the preparation, characterization of the catalysts with highly dispersed and isolated active sites and their applications in other types of reactions of lower hydrocarbons are summarized.

  15. Optimized over-expression of [FeFe] hydrogenases with high specific activity in Clostridium acetobutylicum

    Energy Technology Data Exchange (ETDEWEB)

    von Abendroth, Gregory; Stripp, Sven; Happe, Thomas [Ruhr-Universitaet Bochum, Lehrstuhl fuer Biochemie der Pflanzen, AG Photobiotechnologie, 44780 Bochum (Germany); Silakov, Alexey [Max-Planck-Institut fuer Bioanorganische Chemie, 45470 Muelheim an der Ruhr (Germany); Croux, Christian; Soucaille, Philippe; Girbal, Laurence [UMR5504, UMR792 Ingenierie des Systemes Biologiques et des Procedes, CNRS, INRA, INSA, 31400 Toulouse (France)

    2008-11-15

    It was previously shown that Clostridium acetobutylicum is capable to over-express various [FeFe] hydrogenases although the protein yield was low. In this study we report on doubling the yield of the clostridial hydrogenase by replacing the native gene hydA1{sub Ca} with a recombinant one via homologous recombination. The purified protein HydA1{sub Ca} shows an unexpected high specific activity (up to 2257 {mu}mol H{sub 2} min{sup -1} mg{sup -1}) for hydrogen evolution. Furthermore, the highly active green algal hydrogenase HydA1{sub Cr} from Chlamydomonas reinhardtii was heterologously expressed in C. acetobutylicum, and purified with increased yield (1 mg protein per liter of cells) and high activity (625 {mu}mol H{sub 2} min{sup -1} mg{sup -1}). EPR studies demonstrate intact H-clusters for homologously and heterologously expressed [FeFe] hydrogenases in the CO-inhibited oxidized redox state, and prove the high efficiency of the C. acetobutylicum expression system. (author)

  16. A High Power Density Integrated Charger for Electric Vehicles with Active Ripple Compensation

    Directory of Open Access Journals (Sweden)

    Liwen Pan

    2015-01-01

    Full Text Available This paper suggests a high power density on-board integrated charger with active ripple compensation circuit for electric vehicles. To obtain a high power density and high efficiency, silicon carbide devices are reported to meet the requirement of high-switching-frequency operation. An integrated bidirectional converter is proposed to function as AC/DC battery charger and to transfer energy between battery pack and motor drive of the traction system. In addition, the conventional H-bridge circuit suffers from ripple power pulsating at second-order line frequency, and a scheme of active ripple compensation circuit has been explored to solve this second-order ripple problem, in which a pair of power switches shared traction mode, a ripple energy storage capacitor, and an energy transfer inductor. Simulation results in MATLAB/Simulink validated the eligibility of the proposed topology. The integrated charger can work as a 70 kW motor drive circuit or a converter with an active ripple compensation circuit for 3 kW charging the battery. The impact of the proposed topology and control strategy on the integrated charger power losses, efficiency, power density, and thermal performance has also been analysed and simulated.

  17. Oleanolic acid ameliorates high glucose-induced endothelial dysfunction via PPARδ activation

    Science.gov (United States)

    Zhang, Zihui; Jiang, Manli; Xie, Xinya; Yang, Haixia; Wang, Xinfeng; Xiao, Lei; Wang, Nanping

    2017-01-01

    Oleanolic acid (3β-hydroxyolean-12-en-28-oic acid, OA) is a pentacyclic triterpenes widely distributed in food, medicinal plants and nutritional supplements. OA exhibits various pharmacological properties, such as hepatoprotective and anti-tumor effects. In this study, we analyzed the effect of OA on endothelial dysfunction induced by high glucose in human vascular endothelial cells (ECs). Western blotting showed that OA attenuated high glucose-reduced nitric production oxide (NO) as well as Akt-Ser473 and eNOS-Ser1177 phosphorylation in cultured human umbilical vein ECs (HUVECs). Next, luciferase reporter assay showed that OA activated peroxisome proliferators-activated receptor δ (PPARδ) activity. Quantitative reverse transcriptase PCR (qRT-PCR) demonstrated that OA increased the expressions of PPARδ target genes (PDK4, ADRP and ANGPTL4) in ECs. Meanwhile, the induced expressions of PDK4, ADRP and ANGPTL4 by OA were inhibited by GSK0660, a specific antagonist of PPARδ. In addition, inhibition of PPARδ abolished OA-induced the Akt-Ser473 and eNOS-Ser1177 phosphorylation, and NO production. Finally, by using Multi Myograph System, we showed that OA prevented high glucose-impaired vasodilation. This protective effect on vasodilation was inhibited in aortic rings pretreated with GSK0660. Collectively, we demonstrated that OA improved high glucose-impaired endothelial function via a PPARδ-mediated mechanism and through eNOS/Akt/NO pathway. PMID:28067284

  18. [Change of cholinesterase relative activity under modulated ultra high frequency electromagnetic radiation in experiments in vitro].

    Science.gov (United States)

    Pashovkina, M S; Pashovkin, T N

    2011-01-01

    Changes in the activity of enzyme cholinesterase (ChE) have been experimentally investigated under the influence of amplitude-modulated super-high-frequency electromagnetic radiation (carrier frequency of 2.375 MHz; power flux density of 8 mW/cm2, 20 mW/cm2 and 50 mW/cm2; modulation frequency range 10 to 210 Hz; exposure time 5 min). The appearance of peaks of the cholinesterase increased relative activity, as well as the changes in the direction and intensity of the reaction associated with the modulation frequency and power flux are observed at equal power flux densities and exposure times.

  19. Characterization of Catalase from Psychrotolerant Psychrobacter piscatorii T-3 Exhibiting High Catalase Activity

    OpenAIRE

    Hidetoshi Matsuyma; Isao Yumoto; Hideyuki Kimoto; Kazuaki Yoshimune

    2012-01-01

    A psychrotolerant bacterium, strain T-3 (identified as Psychrobacter piscatorii), that exhibited an extraordinarily high catalase activity was isolated from the drain pool of a plant that uses H2O2 as a bleaching agent. Its cell extract exhibited a catalase activity (19,700 U·mg protein−1) that was higher than that of Micrococcus luteus used for industrial catalase production. Catalase was approximately 10% of the total proteins in the cell extract of the strain. The catalase (PktA) was purif...

  20. Pt5Gd as a Highly Active and Stable Catalyst for Oxygen Electroreduction

    DEFF Research Database (Denmark)

    Escribano, Maria Escudero; Verdaguer-Casadevall, Arnau; Verdaguer Casadevall, Arnau

    2012-01-01

    The activity and stability of Pt5Gd for the oxygen reduction reaction (ORR) have been studied, using a combination of electrochemical measurements, angle-resolved X-ray photoelectron spectroscopy (AR-XPS), and density functional theory calculations. Sputter-cleaned, polycrystalline Pt5Gd shows a 5...... can be explained by means of compressive strain effects. Furthermore, these novel bimetallic electrocatalysts are highly stable, which, in combination with their enhanced activity, makes them very promising for the development of new cathode catalysts for fuel cells....

  1. Photon-activated charge domain in high-gain photoconductive switches

    Institute of Scientific and Technical Information of China (English)

    Wei Shi(施卫); Huiying Dai(戴慧莹); Xiaowei Sun(孙小卫)

    2003-01-01

    We report our experimental observation of charge domain oscillation in semi-insulating GaAs photoconductive semiconductor switches (PCSSs). The high-gain PCSS is intrinsically a photon-activated charge domain device. It is the photon-activated carriers that satisfy the requirement of charge domain formation on carrier concentration and device length product of 1012 cm-2. We also show that, because of the repeated process of domain formation, the domain travels with a compromised speed of electron saturation velocity and the speed of light. As a result, the transit time of charge domains in PCSS is much shorter than that of traditional Gunn domains.

  2. Exploring the Effects of Active Learning on High School Students' Outcomes and Teachers' Perceptions of Biotechnology and Genetics Instruction

    Science.gov (United States)

    Mueller, Ashley L.; Knobloch, Neil A.; Orvis, Kathryn S.

    2015-01-01

    Active learning can engage high school students to learn science, yet there is limited understanding if active learning can help students learn challenging science concepts such as genetics and biotechnology. This quasi-experimental study explored the effects of active learning compared to passive learning regarding high school students'…

  3. Regulation of pyruvate dehydrogenase activity and citric acid cycle intermediates during high cardiac power generation.

    Science.gov (United States)

    Sharma, Naveen; Okere, Isidore C; Brunengraber, Daniel Z; McElfresh, Tracy A; King, Kristen L; Sterk, Joseph P; Huang, Hazel; Chandler, Margaret P; Stanley, William C

    2005-01-15

    A high rate of cardiac work increases citric acid cycle (CAC) turnover and flux through pyruvate dehydrogenase (PDH); however, the mechanisms for these effects are poorly understood. We tested the hypotheses that an increase in cardiac energy expenditure: (1) activates PDH and reduces the product/substrate ratios ([NADH]/[NAD(+)] and [acetyl-CoA]/[CoA-SH]); and (2) increases the content of CAC intermediates. Measurements were made in anaesthetized pigs under control conditions and during 15 min of a high cardiac workload induced by dobutamine (Dob). A third group was made hyperglycaemic (14 mm) to stimulate flux through PDH during the high work state (Dob + Glu). Glucose and fatty acid oxidation were measured with (14)C-glucose and (3)H-oleate. Compared with control, the high workload groups had a similar increase in myocardial oxygen consumption ( and cardiac power. Dob increased PDH activity and glucose oxidation above control, but did not reduce the [NADH]/[NAD(+)] and [acetyl-CoA]/[CoA-SH] ratios, and there were no differences between the Dob and Dob + Glu groups. An additional group was treated with Dob + Glu and oxfenicine (Oxf) to inhibit fatty acid oxidation: this increased [CoA-SH] and glucose oxidation compared with Dob; however, there was no further activation of PDH or decrease in the [NADH]/[NAD(+)] ratio. Content of the 4-carbon CAC intermediates succinate, fumarate and malate increased 3-fold with Dob, but there was no change in citrate content, and the Dob + Glu and Dob + Glu + Oxf groups were not different from Dob. In conclusion, compared with normal conditions, at high myocardial energy expenditure (1) the increase in flux through PDH is regulated by activation of the enzyme complex and continues to be partially controlled through inhibition by fatty acid oxidation, and (2) there is expansion of the CAC pool size at the level of 4-carbon intermediates that is largely independent of myocardial fatty acid oxidation.

  4. Ionospheric response to sudden stratospheric warming events at low and high solar activity

    Science.gov (United States)

    Fang, Tzu-Wei; Fuller-Rowell, Tim; Wang, Houjun; Akmaev, Rashid; Wu, Fei

    2014-09-01

    The sensitivity of the ionospheric response to a sudden stratospheric warming (SSW) event has been examined under conditions of low and high solar activity through simulations using the whole atmosphere model (WAM) and the global ionosphere plasmasphere model (GIP). During non-SSW conditions, simulated daytime mean vertical drifts at the magnetic equator show similar solar activity dependence as an empirical model. Model results of ionospheric total electron content (TEC) and equatorial vertical drift for the January 2009 major SSW, which occurred at very low solar activity conditions, show reasonable agreement with observations. The simulations demonstrate that the E region dynamo is capable of creating the semidiurnal variation of vertical drift. WAM and GIP were also run at high solar activity conditions, using the same lower atmosphere conditions as present in the January 2009 SSW event. The simulations indicate that the amplitude and phase of migrating tides in the dynamo region during the event have similar magnitudes for both solar flux conditions. However, comparing the ionospheric responses to a major SSW under low and high solar activity periods, it was found that the changes in the ionospheric vertical drifts and relative changes in TEC decreased with increasing solar activity. The simulations indicate that the F region dynamo becomes more important throughout the daytime and contributes to the upward drift in the afternoon during the event when the solar activity is higher. Our test simulations also confirm that the increase of the ionospheric conductivity associated with increasing solar activity is responsible for the decrease of vertical drift changes during an SSW. In particular, first, the increase in F region conductivity allows the closure of E region currents through the F region, reducing the polarization electric field before noon. Second, the F region dynamo contributes an upward drift postnoon, maintaining upward drifts till after sunset

  5. Water-activated graphite felt as a high-performance electrode for vanadium redox flow batteries

    Science.gov (United States)

    Kabtamu, Daniel Manaye; Chen, Jian-Yu; Chang, Yu-Chung; Wang, Chen-Hao

    2017-02-01

    A simple, green, novel, time-efficient, and potentially cost-effective water activation method was employed to enhance the electrochemical activity of graphite felt (GF) electrodes for vanadium redox flow batteries (VRFBs). The GF electrode prepared with a water vapor injection time of 5 min at 700 °C exhibits the highest electrochemical activity for the VO2+/VO2+ couple among all the tested electrodes. This is attributed to the small, controlled amount of water vapor that was introduced producing high contents of oxygen-containing functional groups, such as sbnd OH groups, on the surface of the GF fibers, which are known to be electrochemically active sites for vanadium redox reactions. Charge-discharge tests further confirm that only 5 min of GF water activation is required to improve the efficiency of the VRFB cell. The average coulombic efficiency, voltage efficiency, and energy efficiency are 95.06%, 87.42%, and 83.10%, respectively, at a current density of 50 mA cm-2. These voltage and energy efficiencies are determined to be considerably higher than those of VRFB cells assembled using heat-treated GF electrodes without water activation and pristine GF electrodes.

  6. Semi-synthesis of oxygenated dolabellane diterpenes with highly in vitro anti-HIV-1 activity.

    Science.gov (United States)

    Pardo-Vargas, Alonso; Ramos, Freddy A; Cirne-Santos, Claudio Cesar; Stephens, Paulo Roberto; Paixão, Izabel Christina Palmer; Teixeira, Valeria Laneuville; Castellanos, Leonardo

    2014-09-15

    Research on dolabellane diterpenes of brown algae Dictyota spp. has shown that these diterpenoids have strong anti-HIV-1 activity, but there are not data about antiviral activity of dolabellane diterpenes isolated from octocorals, which are antipodes of those isolated from the brown algae. Dolabellanes 13-keto-1(R),11(S)-dolabella-3(E),7(E),12(18)-triene (1) and β-Araneosene (2) were isolated from the Caribbean octocoral Eunicea laciniata, and both showed low anti-HIV-1 activity and low toxicity. Since it was shown that oxygenated dolabellanes from algae have better anti-HIV-1 activity, in this work some derivatives of the main dolabellane of E. laciniata1 were obtained by epoxidation (3), epoxide opening (4), and allylic oxidation (5). The derivatives showed significant improvement in the anti-HIV-1potency (100-fold), being compounds 3 and 5 the most active ones. Their high antiviral activities, along with their low cytotoxicity, make them promissory antiviral compounds; and it is worth noting that the absolute configuration at the ring junction in the dolabellane skeleton does not seem to be determinant in the antiviral potency of these diterpeneoids.

  7. Serum Paraoxonase 1 Activity Is Associated with Fatty Acid Composition of High Density Lipoprotein

    Directory of Open Access Journals (Sweden)

    Maryam Boshtam

    2013-01-01

    Full Text Available Introduction. Cardioprotective effect of high density lipoprotein (HDL is, in part, dependent on its related enzyme, paraoxonase 1 (PON1. Fatty acid composition of HDL could affect its size and structure. On the other hand, PON1 activity is directly related to the structure of HDL. This study was designed to investigate the association between serum PON1 activity and fatty acid composition of HDL in healthy men. Methods. One hundred and forty healthy men participated in this research. HDL was separated by sequential ultracentrifugation, and its fatty acid composition was analyzed by gas chromatography. PON1 activity was measured spectrophotometrically using paraxon as substrate. Results. Serum PON1 activity was directly correlated with the amount of stearic acid and dihomo-gamma-linolenic acid (DGLA. PON1/HDL-C was directly correlated with the amount of miristic acid, stearic acid, and DGLA and was inversely correlated with total amount of ω6 fatty acids of HDL. Conclusion. The fatty acid composition of HDL could affect the activity of its associated enzyme, PON1. As dietary fats are the major determinants of serum lipids and lipoprotein composition, consuming some special dietary fatty acids may improve the activity of PON1 and thereby have beneficial effects on health.

  8. Understanding the different activities of highly promiscuous MbtI by computational methods.

    Science.gov (United States)

    Ferrer, Silvia; Martí, Sergio; Moliner, Vicent; Tuñón, Iñaki; Bertrán, Juan

    2012-03-14

    Salicylate synthase from Mycobacterium tuberculosis, MbtI, is a highly promiscuous Mg(2+) dependent enzyme with up to four distinct activities detected in vitro: isochorismate synthase (IS), isochorismate pyruvate lyase (IPL), salicylate synthase (SS) and chorismate mutase (CM). In this paper, Molecular Dynamic (MD) simulations employing hybrid quantum mechanics/molecular mechanics (QM/MM) potentials have been carried out to get a detailed knowledge of the IS and the IPL activities at the molecular level. According to our simulations, the architecture of the MbtI active site allows catalyzing the two reactions: the isochorismate formation, by means of a stepwise mechanism, and the salicylate production from isochorismate, that appears to be pericyclic in nature. Findings also explain the role of the magnesium cation and the pH dependence activity experimentally observed in MbtI. Mg(2+) would be polarizing and pre-organizing the substrate and active site, as well as shifting the pK(a) values of key active site residues.

  9. Graphdiyne oxides as excellent substrate for electroless deposition of Pd clusters with high catalytic activity.

    Science.gov (United States)

    Qi, Hetong; Yu, Ping; Wang, Yuexiang; Han, Guangchao; Liu, Huibiao; Yi, Yuanping; Li, Yuliang; Mao, Lanqun

    2015-04-29

    Graphdiyne (GDY), a novel kind of two-dimensional carbon allotrope consisting of sp- and sp(2)-hybridized carbon atoms, is found to be able to serve as the reducing agent and stabilizer for electroless deposition of highly dispersed Pd nanoparticles owing to its low reduction potential and highly conjugated electronic structure. Furthermore, we observe that graphdiyne oxide (GDYO), the oxidation form of GDY, can be used as an even excellent substrate for electroless deposition of ultrafine Pd clusters to form Pd/GDYO nanocomposite that exhibits a high catalytic performance toward the reduction of 4-nitrophenol. The high catalytic performance is considered to benefit from the rational design and electroless deposition of active metal catalysts with GDYO as the support.

  10. Influence of Mechanical Activation on Acid Leaching Dephosphorization of High-phosphorus Iron Ore Concentrates

    Institute of Scientific and Technical Information of China (English)

    De-qing ZHU; Hao WANG; Jian PAN; Cong-cong YANG

    2016-01-01

    High pressure roll grinding (HPRG)and ball milling were compared to investigate the influence of me-chanical activation on the acid leaching dephosphorization of a high-phosphorus iron ore concentrate,which was man-ufactured through magnetizing roasting-magnetic separation of high-phosphorus oolitic iron ores.The results indica-ted that when high-phosphorus iron ore concentrates containing 54·92 mass% iron and 0·76 mass% phosphorus were directly processed through acid leaching,iron ore concentrates containing 55·74 mass% iron and 0·33 mass%phosphorus with an iron recovery of 84·64% and dephosphorization of 63·79% were obtained.When high-phosphor-us iron ore concentrates activated by ball milling were processed by acid leaching,iron ore concentrates containing 56·03 mass% iron and 0·21 mass% phosphorus with an iron recovery of 85·65% and dephosphorization of 77·49%were obtained.Meanwhile,when high-phosphorus iron ore concentrates activated by HPRG were processed by acid leaching,iron ore concentrates containing 58·02 mass% iron and 0·10 mass% phosphorus were obtained,with the iron recovery reaching 88·42% and the dephosphorization rate reaching 88·99%.Mechanistic studies demonstrated that ball milling can reduce the particle size,demonstrating a prominent reunion phenomenon.In contrast,HPRG pretreatment contributes to the formation of more cracks within the particles and selective dissociation of iron and P bearing minerals,which can provide the favorable kinetic conditions to accelerate the solid-liquid reaction rate.As such,the crystal structure is destroyed and the surface energy of mineral particles is strengthened by mechanical ac-tivation,further strengthening the dephosphorization.

  11. Modulation of NCC activity by low and high K+ intake: insights into the signaling pathways involved

    Science.gov (United States)

    Castañeda-Bueno, María; Cervantes-Perez, Luz Graciela; Rojas-Vega, Lorena; Arroyo-Garza, Isidora; Vázquez, Norma; Moreno, Erika

    2014-01-01

    Modulation of Na+-Cl− cotransporter (NCC) activity is essential to adjust K+ excretion in the face of changes in dietary K+ intake. We used previously characterized genetic mouse models to assess the role of Ste20-related proline-alanine-rich kinase (SPAK) and with-no-lysine kinase (WNK)4 in the modulation of NCC by K+ diets. SPAK knockin and WNK4 knockout mice were placed on normal-, low-, or high-K+-citrate diets for 4 days. The low-K+ diet decreased and high-K+ diet increased plasma aldosterone levels, but both diets were associated with increased phosphorylation of NCC (phospho-NCC, Thr44/Thr48/Thr53) and phosphorylation of SPAK/oxidative stress responsive kinase 1 (phospho-SPAK/OSR1, Ser383/Ser325). The effect of the low-K+ diet on SPAK phosphorylation persisted in WNK4 knockout and SPAK knockin mice, whereas the effects of ANG II on NCC and SPAK were lost in both mouse colonies. This suggests that for NCC activation by ANG II, integrity of the WNK4/SPAK pathway is required, whereas for the low-K+ diet, SPAK phosphorylation occurred despite the absence of WNK4, suggesting the involvement of another WNK (WNK1 or WNK3). Additionally, because NCC activation also occurred in SPAK knockin mice, it is possible that loss of SPAK was compensated by OSR1. The positive effect of the high-K+ diet was observed when the accompanying anion was citrate, whereas the high-KCl diet reduced NCC phosphorylation. However, the effect of the high-K+-citrate diet was aldosterone dependent, and neither metabolic alkalosis induced by bicarbonate, nor citrate administration in the absence of K+ increased NCC phosphorylation, suggesting that it was not due to citrate-induced metabolic alkalosis. Thus, the accompanying anion might modulate the NCC response to the high-K+ diet. PMID:24761002

  12. Modulation of NCC activity by low and high K(+) intake: insights into the signaling pathways involved.

    Science.gov (United States)

    Castañeda-Bueno, María; Cervantes-Perez, Luz Graciela; Rojas-Vega, Lorena; Arroyo-Garza, Isidora; Vázquez, Norma; Moreno, Erika; Gamba, Gerardo

    2014-06-15

    Modulation of Na(+)-Cl(-) cotransporter (NCC) activity is essential to adjust K(+) excretion in the face of changes in dietary K(+) intake. We used previously characterized genetic mouse models to assess the role of Ste20-related proline-alanine-rich kinase (SPAK) and with-no-lysine kinase (WNK)4 in the modulation of NCC by K(+) diets. SPAK knockin and WNK4 knockout mice were placed on normal-, low-, or high-K(+)-citrate diets for 4 days. The low-K(+) diet decreased and high-K(+) diet increased plasma aldosterone levels, but both diets were associated with increased phosphorylation of NCC (phospho-NCC, Thr(44)/Thr(48)/Thr(53)) and phosphorylation of SPAK/oxidative stress responsive kinase 1 (phospho-SPAK/OSR1, Ser(383)/Ser(325)). The effect of the low-K(+) diet on SPAK phosphorylation persisted in WNK4 knockout and SPAK knockin mice, whereas the effects of ANG II on NCC and SPAK were lost in both mouse colonies. This suggests that for NCC activation by ANG II, integrity of the WNK4/SPAK pathway is required, whereas for the low-K(+) diet, SPAK phosphorylation occurred despite the absence of WNK4, suggesting the involvement of another WNK (WNK1 or WNK3). Additionally, because NCC activation also occurred in SPAK knockin mice, it is possible that loss of SPAK was compensated by OSR1. The positive effect of the high-K(+) diet was observed when the accompanying anion was citrate, whereas the high-KCl diet reduced NCC phosphorylation. However, the effect of the high-K(+)-citrate diet was aldosterone dependent, and neither metabolic alkalosis induced by bicarbonate, nor citrate administration in the absence of K(+) increased NCC phosphorylation, suggesting that it was not due to citrate-induced metabolic alkalosis. Thus, the accompanying anion might modulate the NCC response to the high-K(+) diet. Copyright © 2014 the American Physiological Society.

  13. Production of Medical Radioisotopes with High Specific Activity in Photonuclear Reactions with $\\gamma$ Beams of High Intensity and Large Brilliance

    CERN Document Server

    Habs, D

    2010-01-01

    We study the production of radioisotopes for nuclear medicine in $(\\gamma,x{\\rm n}+y{\\rm p})$ photonuclear reactions or ($\\gamma,\\gamma'$) photoexcitation reactions with high flux [($10^{13}-10^{15}$)$\\gamma$/s], small diameter $\\sim (100 \\, \\mu$m$)^2$ and small band width ($\\Delta E/E \\approx 10^{-3}-10^{-4}$) $\\gamma$ beams produced by Compton back-scattering of laser light from relativistic brilliant electron beams. We compare them to (ion,$x$n$ + y$p) reactions with (ion=p,d,$\\alpha$) from particle accelerators like cyclotrons and (n,$\\gamma$) or (n,f) reactions from nuclear reactors. For photonuclear reactions with a narrow $\\gamma$ beam the energy deposition in the target can be managed by using a stack of thin target foils or wires, hence avoiding direct stopping of the Compton and pair electrons (positrons). $(\\gamma,\\gamma')$ isomer production via specially selected $\\gamma$ cascades allows to produce high specific activity in multiple excitations, where no back-pumping of the isomer to the ground st...

  14. Methylglyoxal-Mediated Stress Correlates with High Metabolic Activity and Promotes Tumor Growth in Colorectal Cancer

    Science.gov (United States)

    Chiavarina, Barbara; Nokin, Marie-Julie; Bellier, Justine; Durieux, Florence; Bletard, Noëlla; Sherer, Félicie; Lovinfosse, Pierre; Peulen, Olivier; Verset, Laurine; Dehon, Romain; Demetter, Pieter; Turtoi, Andrei; Uchida, Koji; Goldman, Serge; Hustinx, Roland; Delvenne, Philippe; Castronovo, Vincent; Bellahcène, Akeila

    2017-01-01

    Cancer cells generally rely on aerobic glycolysis as a major source of energy. Methylglyoxal (MG), a dicarbonyl compound that is produced as a side product during glycolysis, is highly reactive and induces the formation of advanced glycation end-products that are implicated in several pathologies including cancer. All mammalian cells have an enzymatic defense against MG composed by glyoxalases GLO1 and GLO2 that converts MG to d-lactate. Colorectal cancer (CRC) is one of the most frequently occurring cancers with high morbidity and mortality. In this study, we used immunohistochemistry to examine the level of MG protein adducts, in a series of 102 CRC human tumors divided into four clinical stages. We consistently detected a high level of MG adducts and low GLO1 activity in high stage tumors compared to low stage ones suggesting a pro-tumor role for dicarbonyl stress. Accordingly, GLO1 depletion in CRC cells promoted tumor growth in vivo that was efficiently reversed using carnosine, a potent MG scavenger. Our study represents the first demonstration that MG adducts accumulation is a consistent feature of high stage CRC tumors. Our data point to MG production and detoxification levels as an important molecular link between exacerbated glycolytic activity and CRC progression. PMID:28117708

  15. Highly basic CaO nanoparticles in mesoporous carbon materials and their excellent catalytic activity.

    Science.gov (United States)

    Raja, Pradeep Kumar; Chokkalingam, Anand; Priya, Subramaniam V; Balasubramanian, Veerappan V; Benziger, Mercy R; Aldeyab, Salem S; Jayavell, Ramasamy; Ariga, Katsukiho; Vinu, Ajayan

    2012-06-01

    Highly basic CaO nanoparticles immobilized mesoporous carbon materials (CaO-CMK-3) with different pore diameters have been successfully prepared by using wet-impregnation method. The prepared materials were subjected to extensive characterization studies using sophisticated techniques such as XRD, nitrogen adsorption, HRSEM-EDX, HRTEM and temperature programmed desorption of CO2 (TPD of CO2). The physico-chemical characterization results revealed that these materials possess highly dispersed CaO nanoparticles, excellent nanopores with well-ordered structure, high specific surface area, large specific pore volume, pore diameter and very high basicity. We have also demonstrated that the basicity of the CaO-CMK-3 samples can be controlled by simply varying the amount of CaO loading and pore diameter of the carbon support. The basic catalytic performance of the samples was investigated in the base-catalyzed transesterification of ethylacetoacetate by aryl, aliphatic and cyclic primary alcohols. CMK-3 catalyst with higher CaO loading and larger pore diameter was found to be highly active with higher conversion within a very short reaction time. The activity of 30% CaO-CMK3-150 catalyst for transesterification of ethylacetoacetate using different alcohols increases in the following order: octanol > butanol > cyclohexanol > benzyl alcohol > furfuryl alcohol.

  16. Production study of high specific activity NCA Re-186g by proton and deuteron cyclotron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bonardi, M.L., E-mail: mauro.bonardi@mi.infn.i [L.A.S.A., Radiochemistry Laboratory, Universita degli Studi di Milano, UNIMI and Istituto Nazionale di Fisica Nucleare, INFN, Via F.lli Cervi 201, I-20090 Segrate (Italy); Groppi, F.; Manenti, S.; Persico, E.; Gini, L. [L.A.S.A., Radiochemistry Laboratory, Universita degli Studi di Milano, UNIMI and Istituto Nazionale di Fisica Nucleare, INFN, Via F.lli Cervi 201, I-20090 Segrate (Italy)

    2010-09-15

    Very high specific activity (A{sub S}) {sup 186g}Re could be produced by either proton or deuteron cyclotron irradiation on highly enriched {sup 186}W target in no-carrier-added (NCA) form, leading to a A{sub S} very close to the theoretical carrier free (CF) value of 6.88 GBq {mu}g{sup -1}. Thick target yields (TTYs), obtained irradiating both thick metal W targets of natural isotopic composition and highly enriched pressed powdered {sup 186}W targets, were measured at different particles energies taking into account high accuracy and precision on both yield and beam energy. The measurement of radionuclidic purity of {sup 186g}Re obtained activating highly enriched {sup 186}W by both p and d beams were also carried out and accurately compared. The excitation function as thin-target yields (tty, i.e. proportional to the reaction cross-sections) and the integrated TTYs for all Re (A=181, 182, 183, 184, 186 and their metastable levels), W and Ta co-produced radionuclides will be presented elsewhere in deep details.

  17. Effect of high fat diet on artificial oocyte activation following superovulation in mice.

    Science.gov (United States)

    Yamamoto, Daisuke; Yasui, Toshiyuki; Kobayashi, Chika; Kitazato, Takane; Iwasa, Takeshi; Irahara, Minoru

    2016-04-01

    The aim of the present study was to determine the effects of increased dietary intake and high fat diet (HFD) in mice on artificial oocyte activation by using puromycin or roscovitine. Six-week-old mice were fed as eithe