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Sample records for newly synthesized quaternary

  1. Green methodology for the recovery of Cr (VI from tannery effluent using newly synthesized quaternary ammonium salt

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    K.S. Yoganand

    2017-02-01

    Full Text Available Leather tanning industries release effluents into the river through various canals. These effluents contain chromium (VI contaminating the river and the ground water as well. To fix a solution for this issue a simple and selective solvent extraction method has been applied by using a newly synthesized quaternary ammonium salt viz 2-benzoylethylheptyldimethylammonium bromide. By varying the parameters such as quaternary ammonium salts, sulfuric acid, pH, solvents, equilibration time and aqueous organic ratio the extraction efficiency has been determined.

  2. Mutagenicity of quaternary ammonium salts containing carbohydrate moieties

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    Dmochowska, Barbara [Department of Carbohydrate Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Piosik, Jacek; Woziwodzka, Anna [Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Kladki 24, 80-822 Gdansk (Poland); Sikora, Karol; Wisniewski, Andrzej [Department of Carbohydrate Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Wegrzyn, Grzegorz, E-mail: wegrzyn@biotech.univ.gda.pl [Department of Molecular Biology, University of Gdansk, Kladki 24, 80-822 Gdansk (Poland)

    2011-10-15

    Highlights: {yields} A series of quaternary ammonium salts containing carbohydrate moieties, with configuration D-galacto, D-gluco and D-manno, was synthesized and characterized. {yields} The quaternary ammonium salts containing carbohydrate moieties revealed potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. {yields} The N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. {yields} We suggest that quaternary ammonium salts may be more hazardous than previously supposed. - Abstract: Quaternary ammonium salts are widely used in industrial, agricultural, healthcare and domestic applications. They are believed to be safe compounds, with little or no health hazard to humans. However, in this report, we demonstrate that a series of newly synthesized quaternary ammonium salts containing carbohydrate moieties reveal potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. D-Gluco- and D-galacto-derivatives were found to have a higher mutagenic potential than D-manno-derivatives. Among the former groups of compounds, the N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. These results suggest that the safety of quaternary ammonium salts may be lower than previously supposed, indicating a need for testing such compounds for their mutagenicity.

  3. Mutagenicity of quaternary ammonium salts containing carbohydrate moieties

    International Nuclear Information System (INIS)

    Dmochowska, Barbara; Piosik, Jacek; Woziwodzka, Anna; Sikora, Karol; Wisniewski, Andrzej; Wegrzyn, Grzegorz

    2011-01-01

    Highlights: → A series of quaternary ammonium salts containing carbohydrate moieties, with configuration D-galacto, D-gluco and D-manno, was synthesized and characterized. → The quaternary ammonium salts containing carbohydrate moieties revealed potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. → The N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. → We suggest that quaternary ammonium salts may be more hazardous than previously supposed. - Abstract: Quaternary ammonium salts are widely used in industrial, agricultural, healthcare and domestic applications. They are believed to be safe compounds, with little or no health hazard to humans. However, in this report, we demonstrate that a series of newly synthesized quaternary ammonium salts containing carbohydrate moieties reveal potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. D-Gluco- and D-galacto-derivatives were found to have a higher mutagenic potential than D-manno-derivatives. Among the former groups of compounds, the N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. These results suggest that the safety of quaternary ammonium salts may be lower than previously supposed, indicating a need for testing such compounds for their mutagenicity.

  4. Cross-Linking Mast Cell Specific Gangliosides Stimulates the Release of Newly Formed Lipid Mediators and Newly Synthesized Cytokines

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    Edismauro Garcia Freitas Filho

    2016-01-01

    Full Text Available Mast cells are immunoregulatory cells that participate in inflammatory processes. Cross-linking mast cell specific GD1b derived gangliosides by mAbAA4 results in partial activation of mast cells without the release of preformed mediators. The present study examines the release of newly formed and newly synthesized mediators following ganglioside cross-linking. Cross-linking the gangliosides with mAbAA4 released the newly formed lipid mediators, prostaglandins D2 and E2, without release of leukotrienes B4 and C4. The effect of cross-linking these gangliosides on the activation of enzymes in the arachidonate cascade was then investigated. Ganglioside cross-linking resulted in phosphorylation of cytosolic phospholipase A2 and increased expression of cyclooxygenase-2. Translocation of 5-lipoxygenase from the cytosol to the nucleus was not induced by ganglioside cross-linking. Cross-linking of GD1b derived gangliosides also resulted in the release of the newly synthesized mediators, interleukin-4, interleukin-6, and TNF-α. The effect of cross-linking the gangliosides on the MAP kinase pathway was then investigated. Cross-linking the gangliosides induced the phosphorylation of ERK1/2, JNK1/2, and p38 as well as activating both NFκB and NFAT in a Syk-dependent manner. Therefore, cross-linking the mast cell specific GD1b derived gangliosides results in the activation of signaling pathways that culminate with the release of newly formed and newly synthesized mediators.

  5. Localization and movement of newly synthesized cholesterol in rat ovarian granulosa cells

    International Nuclear Information System (INIS)

    Lange, Y.; Schmit, V.M.; Schreiber, J.R.

    1988-01-01

    The distribution and movement of cholesterol were studied in granulosa cells from the ovaries of estrogen-stimulated hypophysectomized immature rats cultured in serum-free medium. Plasma membrane cholesterol was distinguished from intracellular cholesterol with cholesterol oxidase, an enzyme that converts cell surface cholesterol to cholestenone, leaving intracellular cholesterol untouched. Using this approach we showed that 82% of unesterified cholesterol was associated with the plasma membrane in granulosa cells cultured for 48 h in serum-free medium in both the presence and absence of added androstenedione and FSH. FSH and androstenedione stimulated a marked increase in steroid hormone (progestin) production. The movement of newly synthesized cholesterol to the plasma membrane also was followed using cholesterol oxidase. Newly synthesized cholesterol reached the plasma membrane too rapidly to be measured in unstimulated cells (t1/2 less than 20 min); however, in cells stimulated by FSH and androstenedione, this rate was considerably slower (t1/2 approximately 2h). Therefore, cholesterol movement to the plasma membrane appears to be regulated by gonadotropins in these cells. We tested whether steroid biosynthesis used all cell cholesterol pools equally. To this end we administered [3H]acetate and [14C]acetate at different times and determined their relative specific contents in various steroids after defined intervals. The relative ages of the steroids (youngest to oldest) were: lanosterol, progestins, intracellular cholesterol, and plasma membrane cholesterol. This finding suggests that progestins use newly synthesized intracellular cholesterol in preference to preexisting intracellular or cell surface cholesterol

  6. Silica-coated quantum dots fluorescent spheres synthesized using a quaternary 'water-in-oil' microemulsion system

    International Nuclear Information System (INIS)

    Chu Maoquan; Sun Ye; Xu Shi

    2008-01-01

    Nanoscale and microscale silica spheres embedded with multiple CdSe quantum dots (QDs, having average diameters of about 2.4 and 5.0 nm, respectively.) were synthesized by using a quaternary 'water-in-oil' microemulsion. Comparing the uncoated QDs, the quantum yields (QYs) of the silica-coated QD spheres were enhanced when the QD cores were synthesized using mercaptoacetic acid (MA) as a stabilizer, while the QYs were dramatically decreased when the cores were synthesized using citric acid (CA) as a stabilizer. The enhanced QYs could be further improved by heating the silica-coated QDs in aqueous solution. Although the QYs of the silica-coated QDs were not high, these spheres emitted bright fluorescence. The silica shells contained numerous micropores (∼0.58-0.91 nm), and small amounts of toxic ions (such as Cd 2+ ) could be released from the silica spheres. However, the release rate of toxic ions from the silica spheres was significantly reduced compared with that of the uncoated QDs

  7. Bioorthogonal Chemistry for the Isolation and Study of Newly Synthesized Histones and Their Modifications.

    Science.gov (United States)

    Arnaudo, Anna M; Link, A James; Garcia, Benjamin A

    2016-03-18

    The nucleosome is an octamer containing DNA wrapped around one histone H3-H4 tetramer and two histone H2A-H2B dimers. Within the nucleosome, histones are decorated with post-translational modifications. Previous studies indicate that the H3-H4 tetramer is conserved during DNA replication, suggesting that old tetramers serve as a template for the modification of newly synthesized tetramers. Here, we present a method that merges bioorthogonal chemistry with mass spectrometry for the study of modifications on newly synthesized histones in mammalian cells. HeLa S3 cells are dually labeled with the methionine analog azidohomoalanine and heavy (13)C6,(15)N4 isotope labeled arginine. Heavy amino acid labeling marks newly synthesized histones while azidohomoalanine incorporation allows for their isolation using bioorthogonal ligation. Labeled mononucleosomes were covalently linked via a copper catalyzed reaction to a FLAG-GGR-alkyne peptide, immunoprecipitated, and subjected to mass spectrometry for quantitative modification analysis. Mononucleosomes containing new histones were successfully isolated using this approach. Additionally, the development of this method highlights the potential deleterious effects of azidohomoalanine labeling on protein PTMs and cell cycle progression, which should be considered for future studies utilizing bioorthogonal labeling strategies in mammalian cells.

  8. Vibrational imaging of newly synthesized proteins in live cells by stimulated Raman scattering microscopy

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    Wei, Lu; Yu, Yong; Shen, Yihui; Wang, Meng C.; Min, Wei

    2013-01-01

    Synthesis of new proteins, a key step in the central dogma of molecular biology, has been a major biological process by which cells respond rapidly to environmental cues in both physiological and pathological conditions. However, the selective visualization of a newly synthesized proteome in living systems with subcellular resolution has proven to be rather challenging, despite the extensive efforts along the lines of fluorescence staining, autoradiography, and mass spectrometry. Herein, we report an imaging technique to visualize nascent proteins by harnessing the emerging stimulated Raman scattering (SRS) microscopy coupled with metabolic incorporation of deuterium-labeled amino acids. As a first demonstration, we imaged newly synthesized proteins in live mammalian cells with high spatial–temporal resolution without fixation or staining. Subcellular compartments with fast protein turnover in HeLa and HEK293T cells, and newly grown neurites in differentiating neuron-like N2A cells, are clearly identified via this imaging technique. Technically, incorporation of deuterium-labeled amino acids is minimally perturbative to live cells, whereas SRS imaging of exogenous carbon–deuterium bonds (C–D) in the cell-silent Raman region is highly sensitive, specific, and compatible with living systems. Moreover, coupled with label-free SRS imaging of the total proteome, our method can readily generate spatial maps of the quantitative ratio between new and total proteomes. Thus, this technique of nonlinear vibrational imaging of stable isotope incorporation will be a valuable tool to advance our understanding of the complex spatial and temporal dynamics of newly synthesized proteome in vivo. PMID:23798434

  9. EVALUATION OF THE ANTIMICROBIAL EFFECTS OF NEW HETEROCYCLIC BIS-QUATERNARY AMMONIUM COMPOUNDS ON BIOFILMS

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    OANA E. CONSTANTIN

    2016-07-01

    Full Text Available Considering the well-known mechanism of adaptable resistance of microorganisms to chemical compounds through biofilms formation and the widespread use of N-heterocyclic quaternary ammonium salts (QAC as disinfectants, in this study we have evaluate the effect of 8 newly synthesized symmetrical and unsymmetrical diquaternary ammonium salts of 1,2-bis-(4-pyridil-ethane on bacterial biofilms produced by three different bacterial strains. The effect of the exposure to quaternary ammonium salts on biofilm communities was investigated within biofilms obtained in a conventional testing system, on stainless steel and glass surfaces. Differential plate counts were used to characterize the developed communities and the effects of QAC exposure and the results were correlated with epifluorescence microphotographs. The data obtained revealed a significant reduction of bacterial cells in the biofilms tested with 4-7 log CFU for all the QAC.

  10. Interaction Studies between Newly Synthesized Photosensitive Polymer and Ionic Liquids

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    In Tae Kim

    2015-01-01

    Full Text Available In this information age, different kinds of photosensitive materials have been used in the manufacture of information storage devices. But these photosensitive materials have the bane of low diffraction efficiency. In order to solve this problem, we have synthesized a novel photosensitive polymer from epoxy-based azopolymers (with three types of azochromophores. Furthermore, we have studied the interaction between this newly synthesized azopolymer and ionic liquids (ILs. For this purpose, we have used the ammonium and imidazolium families of ILs, such as diethylammonium dihydrogen phosphate (DEAP, tributylammonium methyl sulfate (TBMS, triethylammonium 4-aminotoluene-3-sulfonic acid (TASA, and 1-methylimidazolium chloride ([Mim]Cl. To investigate the molecular interaction between azopolymer and ILs, we have used the following spectroscopic methods of analysis: UV-visible spectroscopy, photoluminescence (PL spectroscopy, Fourier transformed infrared spectroscopy (FT-IR, and confocal Raman spectroscopy. In this study, we have developed new photosensitive materials by combining polymer with ILs.

  11. Release of newly synthesized nucleoplasmic ribosomal subunits or their precursor particles from isolated nuclei of regenerating rat liver

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    Usami, K; Ogata, K [Niigata Univ. (Japan). School of Medicine

    1930-06-16

    The authors present the time course of the labeling of RNA and protein moieties of these particles in vivo as well as the pattern of one-dimensional acrylamide gel electrophoresis of their protein moieties labeled with (/sup 35/S)methionine in vivo, which shows that released 60 S particles are newly synthesized ribosomal large subunits or their precursor particles in the nucleoplasm on their way from the nucleolus to the cytoplasm. It appears likely that released 40 S particles contain newly synthesized ribosomal small subunits or their precursors in the nucleoplasm.

  12. Influence of secretagogues on asynchronous secretion of newly synthesized pancreatic proteins in the conscious rat

    International Nuclear Information System (INIS)

    Keim, V.; Rohr, G.

    1987-01-01

    The secretion of newly synthesized pancreatic enzymes was studied in pancreatic duct cannulated rats after intravenous injection of 100 microCi of [ 35 S]methionine. Secretion rate was stimulated by intravenous infusion of either cerulein (0.2 microgram/kg h) or carbachol (10 nmol/kg h) starting simultaneously with or 180 min before the injection of the labeled methionine. Secretory proteins were analyzed by sodium dodecyl sulfate (SDS) gel electrophoresis or by nondenaturing gel electrophoresis followed by determination of the radioactivity associated with the individual proteins. Similar to unstimulated controls in all experiments, an early secretion of newly synthesized trypsinogen and chymotrypsinogen was found, whereas amylase and lipase were secreted only after a certain lag period. The results suggest that the intracellular transit of endoproteases is faster than that of other enzymes, irrespective of whether or not secretagogues were applied

  13. Direct measurement of newly synthesized ATP dissociation kinetics in sarcoplasmic reticulum ATPase

    International Nuclear Information System (INIS)

    Teruel-Puche, J.; Kurzmack, M.; Inesi, G.

    1987-01-01

    Incubation of SR vesicles with Ca 2+ and ( 32 P)acetylphosphate, yields steady state levels of ( 32 P)phosphorylated enzyme (ATPase) intermediate and high concentrations of Ca 2+ in the lumen of the vesicles. At this time, addition of ADP (and EGTA to lower the Ca 2+ concentration in the medium outside the vesicles) results in single cycle formation of (γ- 32 P)ATP by transfer of ( 32 P)phosphate from the enzyme intermediate to ADP. The phosphoenzyme decay and ATP formation exhibit a fast component within the first 20 msec following addition of ADP, and a slower component reaching an asymptote in approximately 100 msec. They have now measured by a rapid filtration method the fraction of newly synthesized ATP which is bound to the enzyme, as opposed to the fraction dissociated into the medium. They find that nearly all the ATP formed during the initial burst is still bound to the enzyme within the initial 20 msec of reaction. Dissociation of newly synthesized ATP occurs then with approximately 13 sec -1 rate constant, permitting reequilibration of the system and further formation of ATP. The rate limiting effect of ATP dissociation and other partial reactions on the slow component of single cycle ATP synthesis is evaluated by appropriate kinetic simulations

  14. PP32 and SET/TAF-Iβ proteins regulate the acetylation of newly synthesized histone H4.

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    Saavedra, Francisco; Rivera, Carlos; Rivas, Elizabeth; Merino, Paola; Garrido, Daniel; Hernández, Sergio; Forné, Ignasi; Vassias, Isabelle; Gurard-Levin, Zachary A; Alfaro, Iván E; Imhof, Axel; Almouzni, Geneviève; Loyola, Alejandra

    2017-11-16

    Newly synthesized histones H3 and H4 undergo a cascade of maturation steps to achieve proper folding and to establish post-translational modifications prior to chromatin deposition. Acetylation of H4 on lysines 5 and 12 by the HAT1 acetyltransferase is observed late in the histone maturation cascade. A key question is to understand how to establish and regulate the distinct timing of sequential modifications and their biological significance. Here, we perform proteomic analysis of the newly synthesized histone H4 complex at the earliest time point in the cascade. In addition to known binding partners Hsp90 and Hsp70, we also identify for the first time two subunits of the histone acetyltransferase inhibitor complex (INHAT): PP32 and SET/TAF-Iβ. We show that both proteins function to prevent HAT1-mediated H4 acetylation in vitro. When PP32 and SET/TAF-Iβ protein levels are down-regulated in vivo, we detect hyperacetylation on lysines 5 and 12 and other H4 lysine residues. Notably, aberrantly acetylated H4 is less stable and this reduces the interaction with Hsp90. As a consequence, PP32 and SET/TAF-Iβ depleted cells show an S-phase arrest. Our data demonstrate a novel function of PP32 and SET/TAF-Iβ and provide new insight into the mechanisms regulating acetylation of newly synthesized histone H4. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  15. Synthetic Strategies toward Natural Products Containing Contiguous Stereogenic Quaternary Carbon Atoms.

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    Büschleb, Martin; Dorich, Stéphane; Hanessian, Stephen; Tao, Daniel; Schenthal, Kyle B; Overman, Larry E

    2016-03-18

    Strategies for the total synthesis of complex natural products that contain two or more contiguous stereogenic quaternary carbon atoms in their intricate structures are reviewed with 12 representative examples. Emphasis has been put on methods to create quaternary carbon stereocenters, including syntheses of the same natural product by different groups, thereby showcasing the diversity of thought and individual creativity. A compendium of selected natural products containing two or more contiguous stereogenic quaternary carbon atoms and key reactions in their total or partial syntheses is provided in the Supporting Information. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Solid-phase extraction of the alcohol abuse biomarker phosphatidylethanol using newly synthesized polymeric sorbent materials containing quaternary heterocyclic groups.

    Science.gov (United States)

    Duarte, Mariana; Jagadeesan, Kishore Kumar; Billing, Johan; Yilmaz, Ecevit; Laurell, Thomas; Ekström, Simon

    2017-10-13

    Phosphatidylethanol (PEth) is an interesting biomarker finding increased use for detecting long term alcohol abuse with high specificity and sensitivity. Prior to detection, sample preparation is an unavoidable step in the work-flow of PEth analysis and new protocols may facilitate it. Solid-phase extraction (SPE) is a versatile sample preparation method widely spread in biomedical laboratories due to its simplicity of use and the possibility of automation. In this work, SPE was used for the first time to directly extract PEth from spiked human plasma and spiked human blood. A library of polymeric SPE materials with different surface functionalities was screened for PEth extraction in order to identify the surface characteristics that control PEth retention and recovery. The plasma samples were diluted 1:10 (v/v) in water and spiked at different concentrations ranging from 0.3 to 5μM. The library of SPE materials was then evaluated using the proposed SPE method and detection was done by LC-MS/MS. One SPE material efficiently retained and recovered PEth from spiked human plasma. With this insight, four new SPE materials were formulated and synthesized based on the surface characteristics of the best SPE material found in the first screening. These new materials were tested with spiked human blood, to better mimic a real clinical sample. All the newly synthetized materials outperformed the pre-existing commercially available materials. Recovery values for the new SPE materials were found between 29.5% and 48.6% for the extraction of PEth in spiked blood. A material based on quaternized 1-vinylimidazole with a poly(trimethylolpropane trimethacrylate) backbone was found suitable for PEth extraction in spiked blood showing the highest analyte recovery in this experiment, 48.6%±6.4%. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. ATAD2 is an epigenetic reader of newly synthesized histone marks during DNA replication.

    Science.gov (United States)

    Koo, Seong Joo; Fernández-Montalván, Amaury E; Badock, Volker; Ott, Christopher J; Holton, Simon J; von Ahsen, Oliver; Toedling, Joern; Vittori, Sarah; Bradner, James E; Gorjánácz, Mátyás

    2016-10-25

    ATAD2 (ATPase family AAA domain-containing protein 2) is a chromatin regulator harboring an AAA+ ATPase domain and a bromodomain, previously proposed to function as an oncogenic transcription co-factor. Here we suggest that ATAD2 is also required for DNA replication. ATAD2 is co-expressed with genes involved in DNA replication in various cancer types and predominantly expressed in S phase cells where it localized on nascent chromatin (replication sites). Our extensive biochemical and cellular analyses revealed that ATAD2 is recruited to replication sites through a direct interaction with di-acetylated histone H4 at K5 and K12, indicative of newly synthesized histones during replication-coupled chromatin reassembly. Similar to ATAD2-depletion, ectopic expression of ATAD2 mutants that are deficient in binding to these di-acetylation marks resulted in reduced DNA replication and impaired loading of PCNA onto chromatin, suggesting relevance of ATAD2 in DNA replication. Taken together, our data show a novel function of ATAD2 in cancer and for the first time identify a reader of newly synthesized histone di-acetylation-marks during replication.

  18. Bactericidal Specificity and Resistance Profile of Poly(Quaternary Ammonium) Polymers and Protein-Poly(Quaternary Ammonium) Conjugates.

    Science.gov (United States)

    Ji, Weihang; Koepsel, Richard R; Murata, Hironobu; Zadan, Sawyer; Campbell, Alan S; Russell, Alan J

    2017-08-14

    Antibacterial polymers are potentially powerful biocides that can destroy bacteria on contact. Debate in the literature has surrounded the mechanism of action of polymeric biocides and the propensity for bacteria to develop resistance to them. There has been particular interest in whether surfaces with covalently coupled polymeric biocides have the same mechanism of action and resistance profile as similar soluble polymeric biocides. We designed and synthesized a series of poly(quaternary ammonium) polymers, with tailorable molecular structures and architectures, to engineer their antibacterial specificity and their ability to delay the development of bacterial resistance. These linear poly(quaternary ammonium) homopolymers and block copolymers, generated using atom transfer radical polymerization, had structure-dependent antibacterial specificity toward Gram positive and negative bacterial species. When single block copolymers contained two polymer segments of differing antibacterial specificity, the polymer combined the specificities of its two components. Nanoparticulate human serum albumin-poly(quaternary ammonium) conjugates of these same polymers, synthesized via "grafting from" atom transfer radical polymerization, were strongly biocidal and also exhibited a marked decrease in the rate of bacterial resistance development relative to linear polymers. These protein-biocide conjugates mimicked the behavior of surface-presented polycationic biocides rather than their nonproteinaceous counterparts.

  19. Adipokines induce catabolism of newly synthesized matrix in cartilage and meniscus tissues.

    Science.gov (United States)

    Nishimuta, James F; Levenston, Marc E

    Altered synovial levels of various adipokines (factors secreted by fat as well as other tissues) have been associated with osteoarthritis (OA) onset and progression. However, the metabolic effects of adipokines on joint tissues, in particular the fibrocartilaginous menisci, are not well understood. This study investigated effects of several adipokines on release of recently synthesized extracellular matrix in bovine cartilage and meniscus tissue explants. After labeling newly synthesized proteins and sulfated glycosaminoglycans (sGAGs) with 3 H-proline and 35 S-sulfate, respectively; bovine cartilage and meniscus tissue explants were cultured for 6 days in basal medium (control) or media supplemented with adipokines (1 µg/ml of leptin, visfatin, adiponectin, or resistin) or 20 ng/ml interleukin-1 (IL-1). Release of radiolabel and sGAG to the media during culture and the final explant water, DNA, sGAG, and retained radiolabel were measured. Matrix metalloproteinase (MMP-2) and MMP-3 activities were assessed using gelatin and casein zymography, respectively. Water and DNA contents were not significantly altered by any treatment. Visfatin, adiponectin, resistin, and IL-1 stimulated sGAG release from meniscus, whereas only IL-1 stimulated sGAG release from cartilage. Release of 3 H and 35 S was stimulated not only by resistin and IL-1 in meniscus but also by IL-1 in cartilage. Retained 3 H was unaltered by any treatment, while retained 35 S was reduced by visfatin, resistin, and IL-1 in meniscus and by only IL-1 in cartilage. Resistin and IL-1 elevated active MMP-2 and total MMP-3 in meniscus, whereas cartilage MMP-3 activity was elevated by only IL-1. Resistin stimulated rapid and extensive catabolism of meniscus tissue, similar to IL-1, whereas adipokines minimally affected cartilage. Release of newly synthesized matrix was similar to overall release in both tissues. These observations provide further indications that meniscal tissue is more sensitive to pro

  20. Characteristics of newly found Quaternary fault, southern Korea, and its tectonic implication

    Science.gov (United States)

    Lee, Y.; Kim, M. C.; Cheon, Y.; Ha, S.; Kang, H. C.; Choi, J. H.; Son, M.

    2017-12-01

    This study introduces the detailed geometry and kinematics of recently found Quaternary fault in southern Korea, named Seooe Fault, and discusses its tectonic implication through a synthetic analysis with previous studies. The N-S striking Seooe Fault shows a top-to-the-east thrust geometry and cuts the Cretaceous Goseong Formation and overlying Quaternary deposits, and its slip senses and associated minor folds in the hanging wall indicate an E-W compressional stress. The age of the lower part of the Quaternary deposits obtained by OSL dating indicates that the last movement of the fault occurred after 61 60 ka. Arcuate geometry of the main fault showing an upward decreasing dip-angle, reverse offset of the fault breccias, and reverse-sense indicators observed on neighboring N-S striking high-angle fractures indicate that this Quaternary fault was produced by the reactivation of pre-existing fault under E-W compressional stress field. Using the apparent vertical displacement of the fault and the attitudes of cutting slope and main fault surface, its minimum net displacement is calculated as 2.17 m. When the value is applied to the empirical equation of maximum displacement - moment earthquake magnitude (Mw), the magnitude is estimated to reach about 6.7, assuming that this displacement was due to one seismic event. Most of the Quaternary faults in southern Korea are observed along major inherited fault zones, and their geometry and kinematics indicate that they were reactivated under ENE-WSW or E-W compressional stress field, which is concordant with the characteristics of the Seooe Fault. In addition, focal mechanism solutions and geotechnical in-situ stress data in and around the Korean peninsula also support the current ENE-WSW or E-W regional compression. On the basis of the regional stress trajectories in and around East Asia, the current stress field in Korean peninsula is interpreted to have resulted from the cooperation of westward shallow subduction of

  1. Potential of Start Codon Targeted (SCoT) markers for DNA fingerprinting of newly synthesized tritordeums and their respective parents.

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    Cabo, Sandra; Ferreira, Luciana; Carvalho, Ana; Martins-Lopes, Paula; Martín, António; Lima-Brito, José Eduardo

    2014-08-01

    Hexaploid tritordeum (H(ch)H(ch)AABB; 2n = 42) results from the cross between Hordeum chilense (H(ch)H(ch); 2n = 14) and cultivated durum wheat (Triticum turgidum ssp. durum (AABB; 2n = 28). Morphologically, tritordeum resembles the wheat parent, showing promise for agriculture and wheat breeding. Start Codon Targeted (SCoT) polymorphism is a recently developed technique that generates gene-targeted markers. Thus, we considered it interesting to evaluate its potential for the DNA fingerprinting of newly synthesized hexaploid tritordeums and their respective parents. In this study, 60 SCoT primers were tested, and 18 and 19 of them revealed SCoT polymorphisms in the newly synthesized tritordeum lines HT27 and HT22, respectively, and their parents. An analysis of the presence/absence of bands among tritordeums and their parents revealed three types of polymorphic markers: (i) shared by tritordeums and one of their parents, (ii) exclusively amplified in tritordeums, and (iii) exclusively amplified in the parents. No polymorphism was detected among individuals of each parental species. Three SCoT markers were exclusively amplified in tritordeums of lines HT22 and HT27, being considered as polyploidization-induced rearrangements. About 70% of the SCoT markers of H. chilense origin were not transmitted to the allopolyploids of both lines, and most of the SCoTs scored in the newly synthesized allopolyploids originated from wheat, reinforcing the potential use of tritordeum as an alternative crop.

  2. Synthesis and antibacterial activity screening of quaternary ...

    Indian Academy of Sciences (India)

    A series of quaternary ammonium derivatives of triazolyl pyranochromen-2-ones have been synthesized and characterized; their antibacterial potential were investigated against two gram negative (Pseudomonas aeruginosa and Escherichia coli) and two gram positive bacterial strains (Bacillus cereus and Staphylococcus ...

  3. Spectral, stoichiometric ratio, physicochemical, polarity and photostability studies of newly synthesized chalcone dye in organized media

    International Nuclear Information System (INIS)

    Marwani, Hadi M.; Asiri, Abdullah M.; Khan, Salman A.

    2013-01-01

    The main focus of this study was to investigate spectroscopic properties, stoichiometric ratios, physicochemical parameters, polarity and photostability behaviors of newly synthesized chalcone dye in organized media. The chalcone dye, 1-(2,5-Dimethyl-thiophen-3-yl)-3-(9-etnyl-9H-carbazol-3-yl)-propenone (DTEP), was prepared by the reaction of carbazole aldehyde with 3-acetyl-2,5-dimethythiophene. Data obtained from FT-IR, 1 H-–NMR, 13 C-NMR and elemental analysis were consistent with chemical structure of newly prepared DTEP. Increases in fluorescence intensities of DTEP with cetyltrimethyl ammonium bromide (CTAB) were observed. In comparison of fluorescence intensities for DTEP with CTAB, reductions in fluorescence intensities for DTEP with sodium dodecyl sulfate (SDS) were noticed under the same experimental and instrumental conditions. Additionally, Benesi–Hildebrand method was applied to determine stoichiometric ratios and association constants of DTEP with CTAB and SDS. Stern–Volmer plot was used in order to further confirm the stoichiometric ratio and association constant of DTEP with SDS. Physicochemical parameters such as singlet absorption, molar absorptivity, oscillator strength, dipole moment and fluorescence quantum yield of DTEP were also determined. Fluorescence polarity study displayed that DTEP was sensitive to the polarity of the microenvironment provided by different solvents. Finally, fluorescence steady-state measurements revealed that DTEP has high photostability against photobleaching. -- Highlights: ► Mechanistic understanding of molecular structure of newly synthesized chalcone dye. ► Exploring spectral behaviors and physicochemical parameters of chalcone dye. ► Determination of stoichiometric ratios and association constants of chalcone dye. ► Determination of fluorescence quantum yield in different solvents. ► High photostability against photobleaching of chalcone dye was observed

  4. Antibacterial activity of three newly-synthesized chalcones & synergism with antibiotics against clinical isolates of methicillin-resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Dragana D Bozic

    2014-01-01

    Interpretation & conclusions: o0 ur study demonstrated that three newly-synthesized chalcones exhibited significant anti-MRSA effect and synergism with non-β-lactam antibiotics. The most effective compound was 1,3-Bis-(2-hydroxy-phenyl-propenone. Our results provide useful information for future research of possible application of chalcones in combination with conventional anti-MRSA therapy as promising new antimicrobial agents.

  5. Design, synthesis of novel chitosan derivatives bearing quaternary phosphonium salts and evaluation of antifungal activity.

    Science.gov (United States)

    Tan, Wenqiang; Zhang, Jingjing; Luan, Fang; Wei, Lijie; Chen, Yuan; Dong, Fang; Li, Qing; Guo, Zhanyong

    2017-09-01

    Two novel chitosan derivatives modified with quaternary phosphonium salts were successfully synthesized, including tricyclohexylphosphonium acetyl chitosan chloride (TCPACSC) and triphenylphosphonium acetyl chitosan chloride (TPPACSC), and characterized by FTIR, 1 H NMR, and 13 C NMR spectra. The degree of substitution was also calculated by elemental analysis results. Their antifungal activities against Colletotrichum lagenarium, Watermelon fusarium, and Fusarium oxysporum were investigated in vitro using the radial growth assay, minimal inhibitory concentration, and minimum bactericidal concentration assay. The fungicidal assessment revealed that the synthesized chitosan derivatives had superior antifungal activity compared with chitosan. Especially, TPPACSC exhibited the best antifungal property with inhibitory indices of over 75% at 1.0mg/mL. The results obviously showed that quaternary phosphonium groups could effectively enhance antifungal activity of the synthesized chitosan derivatives. Meanwhile, it was also found that their antifungal activity was influenced by electron-withdrawing ability of the quaternary phosphonium salts. The synthetic strategy described here could be utilized for the development of chitosan as antifungal biomaterials. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Synthesis of Main-Chain Chiral Quaternary Ammonium Polymers for Asymmetric Catalysis Using Quaternization Polymerization

    Directory of Open Access Journals (Sweden)

    Md. Masud Parvez

    2012-06-01

    Full Text Available Main-chain chiral quaternary ammonium polymers were successfully synthesized by the quaternization polymerization of cinchonidine dimer with dihalides. The polymerization occurred smoothly under optimized conditions to give novel type of main-chain chiral quaternary ammonium polymers. The catalytic activity of the polymeric chiral organocatalysts was investigated on the asymmetric benzylation of N-(diphenylmethylideneglycine tert-butyl ester.

  7. Hydrazine-hydrothermal syntheses, characterizations and photoelectrochemical properties of two quaternary chalcogenidoantimonates(III) BaCuSbQ{sub 3} (Q = S, Se)

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chang; Hou, Peipei [State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Chai, Wenxiang [College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China); Tian, Jiawei; Zheng, Xuerong; Shen, Yaying; Zhi, Mingjia; Zhou, Chunmei [State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Liu, Yi, E-mail: liuyimse@zju.edu.cn [State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)

    2016-09-15

    Two isostructural quaternary chalcogenidoantimonates(III) BaCuSbQ{sub 3} (Q = S, Se): BaCuSbS{sub 3} (1) and BaCuSbSe{sub 3} (2) have been successfully synthesized through a facile hydrazine-hydrothermal method. Both two compounds crystallize in the orthorhombic space group and feature a three-dimensional (3D) channeled [Cu{sub 2}Sb{sub 2}Q{sub 6}]{sup 4-} framework, which is constructed by the distorted tetrahedral CuQ{sub 4} and pyramid SbQ{sub 3} units via vertex sharing. Both optical properties and theoretical studies show 1 and 2 are semiconductors with narrow band gaps. In addition, their photoelectrochemical properties have been investigated. - Highlights: • BaCuSbQ{sub 3} (Q = S, Se) were synthesized through a hydrazine-hydrothermal method. • BaCuSbQ{sub 3} (Q = S, Se) feature a 3D framework by single-crystal X-ray diffraction. • Experimental and theoretical studies confirm BaCuSbQ{sub 3} (Q = S, Se) are semiconductors. • Photoelectrochemical properties of BaCuSbQ{sub 3} (Q = S, Se) have been investigated.

  8. Quaternary Ammonium Polyethyleneimine: Antibacterial Activity Ira

    International Nuclear Information System (INIS)

    Farber, Y.; Domb, A.G.; Golenser, J.; Beyth, N.; Weiss, E.I.

    2010-01-01

    Quaternary ammonium polyethyleneimine- (QA-PEI-) based nanoparticles were synthesized using two synthetic methods, reductive amination and N-alkylation. According to the first method, QA-PEI nanoparticles were synthesized by cross-linking with glutaraldehyde followed by reductive amination with octanal and further N-methylation with methyl iodide. The second method is based on crosslinking with dialkyl halide followed by N-alkylation with octyl halide and further N-methylation with methyl iodide. QA-PEI nanoparticles completely inhibited bacterial growth (>106 bacteria), including both Gram-positive, that is, Staphylococcus aureus at 80 μ/mL, and Gram-negative, that is, Escherichia coli at 320 μ/mL. Activity analysis revealed that the degree of alkylation and N-methylation of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl alkylated QA-PEI alkylated at 1 : 1 mole ratio (primary amine of PEI monomer units/alkylating agent). Also, cytotoxicity studies on MAT-LyLu and MBT cell lines were performed with QA-PEI nanoparticles. These findings confirm previous reports that poly cations bearing quaternary ammonium moieties inhibit bacterial growth in vitro and have a potential use as additives in medical devices which need antibacterial properties.

  9. New quantum codes constructed from quaternary BCH codes

    Science.gov (United States)

    Xu, Gen; Li, Ruihu; Guo, Luobin; Ma, Yuena

    2016-10-01

    In this paper, we firstly study construction of new quantum error-correcting codes (QECCs) from three classes of quaternary imprimitive BCH codes. As a result, the improved maximal designed distance of these narrow-sense imprimitive Hermitian dual-containing quaternary BCH codes are determined to be much larger than the result given according to Aly et al. (IEEE Trans Inf Theory 53:1183-1188, 2007) for each different code length. Thus, families of new QECCs are newly obtained, and the constructed QECCs have larger distance than those in the previous literature. Secondly, we apply a combinatorial construction to the imprimitive BCH codes with their corresponding primitive counterpart and construct many new linear quantum codes with good parameters, some of which have parameters exceeding the finite Gilbert-Varshamov bound for linear quantum codes.

  10. Measurement of T-lymphocyte responses in whole-blood cultures using newly synthesized DNA and ATP.

    Science.gov (United States)

    Sottong, P R; Rosebrock, J A; Britz, J A; Kramer, T R

    2000-03-01

    The proliferative response is most frequently determined by estimating the amount of [(3)H]thymidine incorporated into newly synthesized DNA. The [(3)H]thymidine procedure requires the use of radioisotopes as well as lengthy periods of incubation (>72 h). An alternative method of assessing T-lymphocyte activation in whole-blood cultures involves the measurement of the nucleotide ATP instead of [(3)H]thymidine incorporation. In addition, the Luminetics assay of T-cell activation measures specific T-lymphocyte subset responses through the use of paramagnetic particles coated with monoclonal antibodies against CD antigens. This assay permits rapid (24 h) analysis of lymphocyte subset activation responses to mitogens and recall antigens in small amounts of blood.

  11. Biodistribution of newly synthesized PHEA-based polymer-coated SPION in Sprague Dawley rats as magnetic resonance contrast agent

    Directory of Open Access Journals (Sweden)

    Park J

    2013-10-01

    Full Text Available Junsung Park,1,2,* Wonkyung Cho,1,2,* Hee Jun Park,1,2 Kwang-Ho Cha,1,2 Dae-Chul Ha,2,5 Youn-Woong Choi,5 Ha-Young Lee,3 Sun-Hang Cho,5 Sung-Joo Hwang1,4 1Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea; 2College of Pharmacy, Chungnam National University, Daejeon, Republic of Korea; 3Biomaterials Laboratory, Korea Research Institutes of Chemical Technology, Daejeon, Republic of Korea; 4College of Pharmacy, Yonsei University, Incheon, Republic of Korea; 5Korea United Pharm Inc, Seoul, Republic of Korea *These authors contributed equally to this work Objectives: The purpose of this study was to observe the pharmacokinetic behavior of newly synthesized biocompatible polymers based on polyhydroxyethylaspartamide (PHEA to be used to coat an iron oxide core to make superparamagnetic iron oxide nanoparticles (SPION. Materials and methods: The isotopes [14C] and [59Fe] were used to label the polymer backbone (CLS and iron oxide core (FLS, respectively. In addition, unradiolabeled cold superparamagnetic iron oxide nanoparticles (SPION/ULS were synthesized to characterize particle size by dynamic light scattering, morphology by transmission electron microscopy, and in vivo magnetic resonance imaging (MRI. CLS and FLS were used separately to investigate the behavior of both the synthesized polymer and [Fe] in Sprague Dawley (SD rats, respectively. Because radioactivity of the isotopes was different by β for CLS and γ for FLS, synthesis of the samples had to be separately prepared. Results: The mean particle size of the ULS was 66.1 nm, and the biodistribution of CLS concentrations in various organs, in rank order of magnitude, was liver > kidney > small intestine > other. The biodistribution of FLS concentrations was liver > spleen > lung > other. These rank orders show that synthesized SPION mainly accumulates in the liver. The differences in the distribution were caused by the SPION metabolism. Radiolabeled

  12. Identification of Newly Synthesized Proteins by Echinococcus granulosus Protoscoleces upon Induction of Strobilation.

    Directory of Open Access Journals (Sweden)

    João Antonio Debarba

    2015-09-01

    Full Text Available The proteins responsible for the key molecular events leading to the structural changes between the developmental stages of Echinococcus granulosus remain unknown. In this work, azidohomoalanine (AHA-specific labeling was used to identify proteins expressed by E. granulosus protoscoleces (PSCs upon the induction of strobilar development.The in vitro incorporation of AHA with different tags into newly synthesized proteins (NSPs by PSCs was analyzed using SDS-PAGE and confocal microscopy. The LC-MS/MS analysis of AHA-labeled NSPs by PSCs undergoing strobilation allowed for the identification of 365 proteins, of which 75 were differentially expressed in comparison between the presence or absence of strobilation stimuli and 51 were expressed exclusively in either condition. These proteins were mainly involved in metabolic, regulatory and signaling processes.After the controlled-labeling of proteins during the induction of strobilar development, we identified modifications in protein expression. The changes in the metabolism and the activation of control and signaling pathways may be important for the correct parasite development and be target for further studies.

  13. Complexes cobalt(II, zinc(II and copper(II with some newly synthesized benzimidazole derivatives and their antibacterial activity

    Directory of Open Access Journals (Sweden)

    S. O. PODUNAVAC-KUZMANOVIC

    1999-05-01

    Full Text Available The preparation and properties of some complexes of cobalt(II, zinc(II and copper(II with several newly synthesized benzimidazole derivatives (L are reported. The complexes, of the general formula [MCl2L2] (M=Co(II, Zn(II and [CuCl2L(H2O], have a tetrahedral structure. The complexes were characterized by elemental analysis, molar conductivity, magnetic susceptibility measurements, IR and absorption electronic spectra. The antibacterial activitiy of the benzimidazoles and their complexes was evaluated against Erwinia carotovora subsp. carotovora and Erwinia amylovora. The complexes were found to be more toxic than the ligands.

  14. Electrochemical Study on Newly Synthesized Chlorocurcumin as an Inhibitor for Mild Steel Corrosion in Hydrochloric Acid

    Directory of Open Access Journals (Sweden)

    Ahmed A. Al-Amiery

    2013-11-01

    Full Text Available A new curcumin derivative, i.e., (1E,4Z,6E-5-chloro-1,7-bis(4-hydroxy-3-methoxyphenylhepta-1,4,6-trien-3-one (chlorocurcumin, was prepared starting with the natural compound curcumin. The newly synthesized compound was characterized by elemental analysis and spectral studies (IR, 1H-NMR and 13C-NMR. The corrosion inhibition of mild steel in 1 M HCl by chlorocurcumin has been studied using potentiodynamic polarization (PDP measurements and electrochemical impedance spectroscopy (EIS. The inhibition efficiency increases with the concentration of the inhibitor but decreases with increases in temperature. The potentiodynamic polarization reveals that chlorocurcumin is a mixed-type inhibitor. The kinetic parameters for mild steel corrosion were determined and discussed.

  15. Electrochemical Study on Newly Synthesized Chlorocurcumin as an Inhibitor for Mild Steel Corrosion in Hydrochloric Acid

    Science.gov (United States)

    Al-Amiery, Ahmed A.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Musa, Ahmed Y.; Li, Cheong Jiun

    2013-01-01

    A new curcumin derivative, i.e., (1E,4Z,6E)-5-chloro-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,4,6-trien-3-one (chlorocurcumin), was prepared starting with the natural compound curcumin. The newly synthesized compound was characterized by elemental analysis and spectral studies (IR, 1H-NMR and 13C-NMR). The corrosion inhibition of mild steel in 1 M HCl by chlorocurcumin has been studied using potentiodynamic polarization (PDP) measurements and electrochemical impedance spectroscopy (EIS). The inhibition efficiency increases with the concentration of the inhibitor but decreases with increases in temperature. The potentiodynamic polarization reveals that chlorocurcumin is a mixed-type inhibitor. The kinetic parameters for mild steel corrosion were determined and discussed. PMID:28788402

  16. Preparation and Characterization of Novel Cationic Chitosan Derivatives Bearing Quaternary Ammonium and Phosphonium Salts and Assessment of Their Antifungal Properties.

    Science.gov (United States)

    Tan, Wenqiang; Li, Qing; Dong, Fang; Chen, Qiuhong; Guo, Zhanyong

    2017-08-31

    Chitosan is an abundant and renewable polysaccharide, its derivatives exhibit attractive bioactivities and the wide applications in various biomedical fields. In this paper, two novel cationic chitosan derivatives modified with quaternary phosphonium salts were successfully synthesized via trimethylation, chloride acetylation, and quaternization with tricyclohexylphosphine and triphenylphosphine. The structures and properties of synthesized products in the reactions were characterized by FTIR spectroscopy, ¹H-NMR, 31 P-NMR, elemental and thermogravimetric analysis. The antifungal activities of chitosan derivatives against four kinds of phytopathogens, including Phomopsis asparagi , Watermelon fusarium , Colletotrichum lagenarium , and Fusarium oxysporum were tested using the radial growth assay in vitro. The results revealed that the synthesized cationic chitosan derivatives showed significantly improved antifungal efficiency compared to chitosan. It was reasonably suggested that quaternary phosphonium groups enabled the obviously stronger antifungal activity of the synthesized chitosans. Especially, the triphenylphosphonium-functionalized chitosan derivative inhibited the growth of Phomopsis asparagi most effectively, with inhibitory indices of about 80% at 0.5 mg/mL. Moreover, the data demonstrated that the substituted groups with stronger electron-withdrawing ability relatively possessed greater antifungal activity. The results suggest the possibility that cationic chitosan derivatives bearing quaternary phosphonium salts could be effectively employed as novel antifungal biomaterials for application in the field of agriculture.

  17. Quaternary and Geomorphology.

    Science.gov (United States)

    Andrews, J. T.; Graf, W. L.

    1983-01-01

    Highlights conferences and meetings of organizations involved with quaternary geology and geomorphology, including International Union of Quaternary Research Conference held in Moscow. The impetus of a revision of "The Quaternary of the United States" resulted from this conference. Includes activities/aims of "Friends of the…

  18. A newly synthesized macakurzin C-derivative attenuates acute and chronic skin inflammation: The Nrf2/heme oxygenase signaling as a potential target

    Energy Technology Data Exchange (ETDEWEB)

    Akram, Muhammad [College of Pharmacy Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan (Korea, Republic of); Shin, Iljin [College of Pharmacy and Research Institute of Pharmaceutical Science and Technology (RIPST), Ajou University, Suwon (Korea, Republic of); Kim, Kyeong-A; Noh, Dabi [College of Pharmacy Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan (Korea, Republic of); Baek, Seung-Hoon; Chang, Sun-Young [College of Pharmacy and Research Institute of Pharmaceutical Science and Technology (RIPST), Ajou University, Suwon (Korea, Republic of); Kim, Hyoungsu, E-mail: hkimajou@ajou.ac.kr [College of Pharmacy and Research Institute of Pharmaceutical Science and Technology (RIPST), Ajou University, Suwon (Korea, Republic of); Bae, Ok-Nam, E-mail: onbae@hanyang.ac.kr [College of Pharmacy Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan (Korea, Republic of)

    2016-09-15

    Impaired immune responses in skin play a pivotal role in the development and progression of chemical-associated inflammatory skin disorders. In this study, we synthesized new flavonoid derivatives from macakurzin C, and identified in vitro and in vivo efficacy of a potent anti-inflammatory flavonoid, Compound 14 (CPD 14), with its underlying mechanisms. In lipopolysaccharide (LPS)-stimulated murine macrophages and IFN-γ/TNF-α-stimulated human keratinocytes, CPD 14 significantly inhibited the release of inflammatory mediators including nitric oxide (NO), prostaglandins, and cytokines (IC{sub 50} for NO inhibition in macrophages: 4.61 μM). Attenuated NF-κB signaling and activated Nrf2/HO-1 pathway were responsible for the anti-inflammatory effects of CPD 14. The in vivo relevance was examined in phorbol 12-myristate 13-acetate (TPA)-induced acute skin inflammation and oxazolone-induced atopic dermatitis models. Topically applied CPD 14 significantly protected both irritation- and sensitization-associated skin inflammation by suppressing the expression of inflammatory mediators. In summary, we demonstrated that a newly synthesized flavonoid, CPD 14, has potent inhibitory effects on skin inflammation, suggesting it is a potential therapeutic candidate to treat skin disorders associated with excessive inflammation. - Highlights: • An anti-inflammatory flavonoid CPD 14 was newly synthesized from macakurzin C. • CPD 14 potently inhibited inflammatory reaction in keratinocytes and macrophages. • Dermal toxicity by irritation or sensitization in rats was protected by CPD 14. • Attenuated NF-κB and activated Nrf2/HO-1 were main mechanisms of CPD 14 action.

  19. Influence of branched quaternary ammonium surfactant molecules as levelers for copper electroplating from acidic sulfate bath

    International Nuclear Information System (INIS)

    Wang, An-yin; Chen, Biao; Fang, Lei; Yu, Jian-jun; Wang, Li-min

    2013-01-01

    A family of branched quaternary ammonium surfactants (compounds 1a–1c) with different carbon chains were synthesized for levelers applied in copper electroplating. Their inhibitory actions on copper electroplating were characterized by cyclic voltammetry (CV). Compound 1b, as representative structure type, was tested by means of different electrochemical methods including CV, polarization curve and electrochemical impedance spectroscopy (EIS) with different concentrations. The interaction between compound 1b and copper surface was investigated using atomic force microscope (AFM) and X-ray photoelectron spectra (XPS). The results indicated that our newly synthesized compounds, particular 1b, were effective levelers used for copper electroplating. Compound 1b could adsorb on copper surface to form an adsorption layer. The adsorption behavior of compound 1b on copper surface indicated that compound 1b could inhibit the copper electrodeposition, which provided favorable conditions used as a leveler. Moreover, the addition of compound 1b could increase the cathodic polarization, which was attributed to the adsorption of compound 1b during copper electroplating process. In addition, various surface morphologies and crystalline orientation of the plated copper films caused by different concentrations of compound 1b were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD) respectively. Effects of compound 1b on refining the grain size and changing the preferential orientation of the plated copper films were exhibited

  20. Formal total syntheses of classic natural product target molecules via palladium-catalyzed enantioselective alkylation

    Directory of Open Access Journals (Sweden)

    Yiyang Liu

    2014-10-01

    Full Text Available Pd-catalyzed enantioselective alkylation in conjunction with further synthetic elaboration enables the formal total syntheses of a number of “classic” natural product target molecules. This publication highlights recent methods for setting quaternary and tetrasubstituted tertiary carbon stereocenters to address the synthetic hurdles encountered over many decades across multiple compound classes spanning carbohydrate derivatives, terpenes, and alkaloids. These enantioselective methods will impact both academic and industrial settings, where the synthesis of stereogenic quaternary carbons is a continuing challenge.

  1. KFeSbTe3: A quaternary chalcogenide aerogel for preferential adsorption of polarizable hydrocarbons and gases

    KAUST Repository

    Ahmed, Ejaz; Rothenberger, Alexander

    2015-01-01

    The first telluride-based quaternary aerogel KFeSbTe3 is synthesized by a sol-gel metathesis reaction between Fe(OAc)2 and K3SbTe3 in dimethyl formamide. The aerogel has an exceptionally large surface area 652 m2 g-1 which is amongst the highest

  2. Size and frequency of gaps in newly synthesized DNA of xeroderma pigmentosum human cells irradiated with ultraviolet light

    International Nuclear Information System (INIS)

    Meneghini, R.; Cordeiro-Stone, M.; Schumacher, R.I.

    1981-01-01

    Native newly synthesized DNA from human cells (xeroderma pigmentosum type) irradiated with ultraviolet light releases short pieces of DNA (L-DNA) when incubated with the single-strand specific S 1 nuclease. This is not observed in the case of unirradiated cells. Previous experiments had shown that the L-DNA resulted from the action of S 1 nuclease upon gaps, i.e., single-stranded DNA discontinuities in larger pieces of double-stranded DNA. We verified that the duplex L-DNA, that arises from the inter-gap regions upon S 1 nuclease treatment, has a size which approximates the distance between two pyrimidine dimers on the same strand. A method was devised to measure the size of the gaps. These parameters have been considered in the proposition of a model for DNA synthesis on a template containing pyrimidine dimers

  3. Synthesis of inulin derivatives with quaternary phosphonium salts and their antifungal activity.

    Science.gov (United States)

    Chen, Yuan; Tan, Wenqiang; Li, Qing; Dong, Fang; Gu, Guodong; Guo, Zhanyong

    2018-03-13

    Inulin is a kind of renewable and biodegradable carbohydrate with good water solubility and numerous physiological functions. For further utilization of inulin, chemical modification can be applied to improve its bioactivities. In this paper, five novel inulin derivatives were synthesized via chemical modification with quaternary phosphonium salt. Their antifungal activity against three kinds of plant pathogens including Colletotrichum lagenarium, Phomopsis asparagi, and Fusarium oxysporum was assessed with radial growth assay in vitro. Results revealed that all the inulin derivatives exhibited improved antifungal activity compared with inulin. Particularly, inulin modified with triphenylphosphine (TPhPAIL) exhibited the best antifungal activity with inhibitory indices of 80.0%, 78.8%, and 87.4% against Colletotrichum lagenarium, Phomopsis asparagi, and Fusarium oxysporum at 1.0mg/mL respectively. The results clearly showed that chemical modification of inulin with quaternary phosphonium salt could efficiently improve derivatives' antifungal activity. Further analysis of results indicated that the antifungal activity was influenced by alkyl chain length or electron-withdrawing ability of the grafted quaternary phosphonium salts. Longer alkyl chain lengths or the stronger electron-withdrawing groups would lead to enhanced antifungal efficacy. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Spectroscopic and structural study of the newly synthesized heteroligand complex of copper with creatinine and urea.

    Science.gov (United States)

    Gangopadhyay, Debraj; Singh, Sachin Kumar; Sharma, Poornima; Mishra, Hirdyesh; Unnikrishnan, V K; Singh, Bachcha; Singh, Ranjan K

    2016-02-05

    Study of copper complex of creatinine and urea is very important in life science and medicine. In this paper, spectroscopic and structural study of a newly synthesized heteroligand complex of copper with creatinine and urea has been discussed. Structural studies have been carried out using DFT calculations and spectroscopic analyses were carried out by FT-IR, Raman, UV-vis absorption and fluorescence techniques. The copper complex of creatinine and the heteroligand complex were found to have much increased water solubility as compared to pure creatinine. The analysis of FT-IR and Raman spectra helps to understand the coordination properties of the two ligands and to determine the probable structure of the heteroligand complex. The LIBS spectra of the heteroligand complex reveal that the complex is free from other metal impurities. UV-visible absorption spectra and the fluorescence emission spectra of the aqueous solution of Cu-Crn-urea heteroligand complex at different solute concentrations have been analyzed and the complex is found to be rigid and stable in its monomeric form at very low concentrations. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. The Human Nuclear Exosome Targeting Complex Is Loaded onto Newly Synthesized RNA to Direct Early Ribonucleolysis

    Directory of Open Access Journals (Sweden)

    Michal Lubas

    2015-01-01

    Full Text Available The RNA exosome complex constitutes the major nuclear eukaryotic 3′-5′ exonuclease. Outside of nucleoli, the human nucleoplasmic exosome is directed to some of its substrates by the nuclear exosome targeting (NEXT complex. How NEXT targets RNA has remained elusive. Using an in vivo crosslinking approach, we report global RNA binding sites of RBM7, a key component of NEXT. RBM7 associates broadly with RNA polymerase II-derived RNA, including pre-mRNA and short-lived exosome substrates such as promoter upstream transcripts (PROMPTs, enhancer RNAs (eRNAs, and 3′-extended products from snRNA and replication-dependent histone genes. Within pre-mRNA, RBM7 accumulates at the 3′ ends of introns, and pulse-labeling experiments demonstrate that RBM7/NEXT defines an early exosome-targeting pathway for 3′-extended snoRNAs derived from such introns. We propose that RBM7 is generally loaded onto newly synthesized RNA to accommodate exosome action in case of available unprotected RNA 3′ ends.

  6. Newly synthesized proteins in seminiferous intertubular and intratubular compartments of the rat testis

    International Nuclear Information System (INIS)

    Shabanowitz, R.B.; Kierszenbaum, A.L.

    1986-01-01

    Two-dimensional gel electrophoresis combined with autoradiography and Western blot procedures have been used to characterize newly synthesized proteins in testicular intertubular fluid (TIF) and seminiferous tubular fluid (SNF). Fluids were collected following in vivo and in vitro intratesticular injection of [ 35 S]methionine into control and hypophysectomized adult rats. A discrete number of [ 35 S]methionine-labeled proteins were detected within TIF and SNF. Their presence and relative abundance varied according to in vivo and in vitro labeling conditions. While two major blood plasma proteins, albumin and transferrin, were radioactively labeled after in vivo labeling, these two proteins were insignificantly labeled in samples collected after in vitro labeling. Three acidic proteins, possibly secreted by Sertoli cells (Mr = 72,000, 45,000 and 35,000), were more abundant in TIF samples collected after in vitro [ 35 S]methionine labeling than after in vivo labeling. Incubated seminiferous tubules and TIF of hypophysectomized rats showed a decrease in [35S]methionine-labeling intensity of the Mr = 72,000 acidic protein, possibly reflecting changes in the seminiferous epithelium caused by pituitary hormonal deprivation. Autoradiographs of TIF and most remarkably, of SNF, showed many protein spots that suggested cell breakage and leakage during sample collection. Results of this study suggest that most albumin and transferrin found in TIF and SNF have an extratesticular origin and that proteins secreted by the Sertoli cell can gain access to both TIF and SNF

  7. Preparation of porous three-dimensional quaternary thioantimonates(III) ACuSb{sub 2}S{sub 4} (A=Rb, Cs) through a surfactant-thermal method

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Yaying; Liu, Chang; Hou, Peipei; Zhi, Mingjia; Zhou, Chunmei; Liu, Yi [Zhejiang Univ., Hangzhou (China). State Key Lab. of Silicon Materials; Chai, Wenxiang [China Jiliang Univ., Hangzhou (China). College of Materials Science and Engineering; Cheng, Jian-Wen [Zhejiang Normal Univ., Jinhua (China). Inst. of Physical Chemistry; Zhang, Quichun [Nanyang Technological Univ., Singapore (Singapore). School of Materials Science and Engineering; Nanyang Technological Univ., Singapore (Singapore). Div. of Chemistry and Biological Chemistry

    2015-12-15

    Two novel porous three-dimensional quaternary thioantimonates(III) ACuSb{sub 2}S{sub 4} (A=Rb, Cs) were successfully synthesized by employing the neutral surfactant PEG-400 (PEG=polyethyleneglycol) as reaction media, these are significantly different from the known quaternary A-Cu-Sb-S thioantimonates(III) with two-dimensional (2D) crystal structures. This is the first time that crystalline quaternary chalcogenides have been prepared in surfactant media. Both experimental and theoretical studies confirm they are semiconductors with narrow band gaps. Our results demonstrated that the surfactant-thermal strategy could offer a new opportunity to explore novel chalcogenides with diverse crystal structures and interesting physicochemical properties.

  8. Newly Synthesized Doxorubicin Complexes with Selected Metals—Synthesis, Structure and Anti-Breast Cancer Activity

    Directory of Open Access Journals (Sweden)

    Agata Jabłońska-Trypuć

    2017-07-01

    Full Text Available Doxorubicin (DOX is very effective chemotherapeutic agent, however it has several major drawbacks. Therefore the motivation for developing novel drug complexes as anticancer agents with different mechanism of action has arisen. The aim of the present study was to evaluate the influence of newly synthesized DOX complexes with selected metals (Mg, Mn, Co, Ni, Fe, Cu, Zn on apoptosis, cell cycle, viability, proliferation and cytotoxicity in the breast cancer cell line MCF-7. Complexation of DOX with metals has likewise been the subject of our research. The current work showed that the tested bivalent metals at a given pH condition formed metal:DOX complexes in a ratio of 2:1, while iron complexes with DOX in a ratio of 3:1. The studies also showed that selected metal-DOX complexes (Mg-DOX, Mn-DOX, Ni-DOX at 0.5 µM concentration significantly decreased cell viability and proliferation, however they increased caspase 7 activity. Results also indicated that studied metal-DOX complexes showed high cytotoxicity in MCF-7 cells. Therefore they were chosen for cell cycle check-points and apoptosis/necrosis analysis studied by flow cytometry. Obtained results suggest that doxorubicin complexed by specified metals can be considered as a potential anti-breast cancer agent, which is characterized by a higher efficacy than a parent drug.

  9. Fluorescence quenching of newly synthesized biologically active coumarin derivative by aniline in binary solvent mixtures

    International Nuclear Information System (INIS)

    Evale, Basavaraj G.; Hanagodimath, S.M.

    2009-01-01

    The fluorescence quenching of newly synthesized coumarin (chromen-2-one) derivative, 4-(5-methyl-3-furan-2-yl-benzofuran-2-yl)-7-methyl-chromen-2-one (MFBMC) by aniline in different solvent mixtures of benzene and acetonitrile was determined at room temperature (296 K) by steady-state fluorescence measurements. The quenching is found to be appreciable and positive deviation from linearity was observed in the Stern-Volmer (S-V) plots in all the solvent mixtures. This could be explained by static and dynamic quenching models. The positive deviation in the S-V plot is interpreted in terms of ground-state complex formation model and sphere of action static quenching model. Various rate parameters for the fluorescence quenching process have been determined by using the modified Stern-Volmer equation. The sphere of action static quenching model agrees very well with experimental results. The dependence of Stern-Volmer constant K SV , on dielectric constant ε of the solvent mixture suggests that the fluorescence quenching is diffusion-limited. Further with the use of finite sink approximation model, it is concluded that these bimolecular quenching reactions are diffusion-limited. Using lifetime (τ o ) data, the distance parameter R' and mutual diffusion coefficient D are estimated independently.

  10. Synthesis of quaternary derivatives of ortho-coco di-amido toluene and investigation of these compounds as cationic bitumen emulsifier

    Energy Technology Data Exchange (ETDEWEB)

    Hassanzadeh, Masoumeh; Tayebi, Leila; Dezfouli, Hedieh; Kambarani, Masoud; Avval, Parviz Ahmadi [Tehran Univ. (Iran, Islamic Republic of). ACECR, Designing Chemical Process Research Group

    2012-05-15

    Bitumen emulsions are preferred over conventional pavement systems due to their biologically and environmentally acceptable formulation, safety, low viscosity, storage stability, and cost effectiveness. The present investigation deals with the systematic study to synthesize ortho-cocodi-amido toluene and four quaternary derivatives by amidation of coconut oil and ortho toluene diamine (OTD), followed by quaternization with formaldehyde, formic acid mixture, and acrylonitrile, resulted in a new quaternary compound useful as cationic emulsifier in bitumen emulsions. The roles of temperature and reaction time in determining optimum conditions were investigated as well. Emulsifying behavior of these quaternary compounds was studied by sieve residue test, settlement and storage stability test of emulsified asphalt, and water solubility. The results show that the acrylonitrile imidazolinium derivative of o-cocodi-amido toluene (VI) can be used as a rapid-medium setting emulsifier. (orig.)

  11. Soft antimicrobial agents: synthesis and activity of labile environmentally friendly long chain quaternary ammonium compounds.

    Science.gov (United States)

    Thorsteinsson, Thorsteinn; Másson, Már; Kristinsson, Karl G; Hjálmarsdóttir, Martha A; Hilmarsson, Hilmar; Loftsson, Thorsteinn

    2003-09-11

    A series of soft quaternary ammonium antimicrobial agents, which are analogues to currently used quaternary ammonium preservatives such as cetyl pyridinium chloride and benzalkonium chloride, were synthesized. These soft analogues consist of long alkyl chain connected to a polar headgroup via chemically labile spacer group. They are characterized by facile nonenzymatic and enzymatic degradation to form their original nontoxic building blocks. However, their chemical stability has to be adequate in order for them to have antimicrobial effects. Stability studies and antibacterial and antiviral activity measurements revealed relationship between activity, lipophilicity, and stability. Their minimum inhibitory concentration (MIC) was as low as 1 microg/mL, and their viral reduction was in some cases greater than 6.7 log. The structure-activity studies demonstrate that the bioactive compounds (i.e., MIC for Gram-positive bacteria of <10 microg/mL) have an alkyl chain length between 12 and 18 carbon atoms, with a polar headgroup preferably of a small quaternary ammonium group, and their acquired inactivation half-life must be greater than 3 h at 60 degrees C.

  12. Vasorelaxant Effect of a Newly Synthesized Dihydropyridine Ethyl Ester (DHPEE on Rat Thoracic Aorta: Dual Mechanism of Action

    Directory of Open Access Journals (Sweden)

    Hossein Babaei

    2011-06-01

    Full Text Available Introduction: DHPEE is a newly synthesized compound by merging the key structural elements in an angiotensin receptor blocker (Telmisartan with key structural elements in 1,4- dihydropyridine calcium channel blocker (Nifedipine. In this study, we examined dual calcium channel blocking and AT1 antagonist activity for DHPEE. Methods: The functional inhibitory characteristics of DHPEE were studied in vitro in rat thoracic aorta preparations precontracted by phenylephrine (1µM or KCl (80µM or Ang II in normal or calcium-free solutions. Results: Concentration–dependent significant relaxation was observed in aortic rings precontracted with phenylephrine, KCl or Ang II. The tension increment produced by increasing external calcium was also reduced by DHPEE. DHPEE caused a marked decrease in the maximal contractile response of the vasoactive agents and shifted their concentration-response curves to the right. Conclusion: DHPEE possesses dual characteristics and cause vasorelaxation by blocking the L-type calcium channels and blocking Ang II receptors (AT1 in rat aortic smooth muscle.

  13. Synthesis and Characterization of Novel Ternary and Quaternary Alkali Metal Thiophosphates

    KAUST Repository

    Alahmary, Fatimah S.

    2014-05-01

    The ongoing development of nonlinear optical (NLO) crystals such as coherent mid-IR sources focuses on various classes of materials such as ternary and quaternary metal chalcophosphates. In case of thiophosphates, the connection between PS4-tetrahedral building blocks and metals gives rise to a broad structural variety where approximately one third of all known ternary (A/P/S) and quaternary (A/M/P/S) (A = alkali metal, M = metal) structures are acentric and potential nonlinear optical materials. The molten alkali metal polychalcophosphate fluxes are a well-established method for the synthesis of new ternary and quaternary thiophosphate and selenophosphate compounds. It has been a wide field of study and investigation through the last two decades. Here, the flux method is used for the synthesis of new quaternary phases containing Rb, Ag, P and S. Four new alkali metal thiophosphates, Rb4P2S10, RbAg5(PS4), Rb2AgPS4 and Rb3Ag9(PS4)4, have been synthesized successfully from high purity elements and binary starting materials. The new compounds were characterized by single crystal and powder X-ray diffraction, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), ultraviolet-visible (UV-VIS), Raman spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). These compounds show interesting structural variety and physical properties. The crystal structures feature 3D anionic framework built up of PS4 tetrahedral units and charge balanced by Ag and alkali metal cations. All prepared compounds are semiconductors with band gap between 2.3 eV to 2.6 eV and most of them are thermally stable up to 600ºC.

  14. Association with β-COP Regulates the Trafficking of the Newly Synthesized Na,K-ATPase*

    Science.gov (United States)

    Morton, Michael J.; Farr, Glen A.; Hull, Michael; Capendeguy, Oihana; Horisberger, Jean-Daniel; Caplan, Michael J.

    2010-01-01

    Plasma membrane expression of the Na,K-ATPase requires assembly of its α- and β-subunits. Using a novel labeling technique to identify Na,K-ATPase partner proteins, we detected an interaction between the Na,K-ATPase α-subunit and the coat protein, β-COP, a component of the COP-I complex. When expressed in the absence of the Na,K-ATPase β-subunit, the Na,K-ATPase α-subunit interacts with β-COP, is retained in the endoplasmic reticulum, and is targeted for degradation. In the presence of the Na,K-ATPase β-subunit, the α-subunit does not interact with β-COP and traffics to the plasma membrane. Pulse-chase experiments demonstrate that in cells expressing both the Na,K-ATPase α- and β-subunits, newly synthesized α-subunit associates with β-COP immediately after its synthesis but that this interaction does not constitute an obligate intermediate in the assembly of the α- and β-subunits to form the pump holoenzyme. The interaction with β-COP was reduced by mutating a dibasic motif at Lys54 in the Na,K-ATPase α-subunit. This mutant α-subunit is not retained in the endoplasmic reticulum and reaches the plasma membrane, even in the absence of Na,K-ATPase β-subunit expression. Although the Lys54 α-subunit reaches the cell surface without need for β-subunit assembly, it is only functional as an ion-transporting ATPase in the presence of the β-subunit. PMID:20801885

  15. Turbulence and Cavitation Suppression by Quaternary Ammonium Salt Additives.

    Science.gov (United States)

    Naseri, Homa; Trickett, Kieran; Mitroglou, Nicholas; Karathanassis, Ioannis; Koukouvinis, Phoevos; Gavaises, Manolis; Barbour, Robert; Diamond, Dale; Rogers, Sarah E; Santini, Maurizio; Wang, Jin

    2018-05-16

    We identify the physical mechanism through which newly developed quaternary ammonium salt (QAS) deposit control additives (DCAs) affect the rheological properties of cavitating turbulent flows, resulting in an increase in the volumetric efficiency of clean injectors fuelled with diesel or biodiesel fuels. Quaternary ammonium surfactants with appropriate counterions can be very effective in reducing the turbulent drag in aqueous solutions, however, less is known about the effect of such surfactants in oil-based solvents or in cavitating flow conditions. Small-angle neutron scattering (SANS) investigations show that in traditional DCA fuel compositions only reverse spherical micelles form, whereas reverse cylindrical micelles are detected by blending the fuel with the QAS additive. Moreover, experiments utilising X-ray micro computed tomography (micro-CT) in nozzle replicas, quantify that in cavitation regions the liquid fraction is increased in the presence of the QAS additive. Furthermore, high-flux X-ray phase contrast imaging (XPCI) measurements identify a flow stabilization effect in the region of vortex cavitation by the QAS additive. The effect of the formation of cylindrical micelles is reproduced with computational fluid dynamics (CFD) simulations by including viscoelastic characteristics for the flow. It is demonstrated that viscoelasticity can reduce turbulence and suppress cavitation, and subsequently increase the injector's volumetric efficiency.

  16. Palladium-Catalyzed Asymmetric Conjugate Addition of Arylboronic Acids to Five-, Six-, and Seven-Membered β-Substituted Cyclic Enones: Enantioselective Construction of All-Carbon Quaternary Stereocenters

    KAUST Repository

    Kikushima, Kotaro

    2011-05-11

    The first enantioselective Pd-catalyzed construction of all-carbon quaternary stereocenters via 1,4-addition of arylboronic acids to β-substituted cyclic enones is reported. Reaction of a wide range of arylboronic acids and cyclic enones using a catalyst prepared from Pd(OCOCF(3))(2) and a chiral pyridinooxazoline ligand yields enantioenriched products bearing benzylic stereocenters. Notably, this transformation is tolerant to air and moisture, providing a practical and operationally simple method of synthesizing enantioenriched all-carbon quaternary stereocenters.

  17. Galvanostatic bottom-up filling of TSV-like trenches: Choline-based leveler containing two quaternary ammoniums

    International Nuclear Information System (INIS)

    Kim, Myung Jun; Seo, Youngran; Kim, Hoe Chul; Lee, Yoonjae; Choe, Seunghoe; Kim, Young Gyu; Cho, Sung Ki; Kim, Jae Jeong

    2015-01-01

    Highlights: • The choline-based leveler having two quaternary ammoniums was synthesized. • The adsorption of this leveler with suppressor and accelerator was examined. • Galvanostatic Cu bottom-up filling was achieved with three-additive system. • The mechanism of gap-filling was elucidated based on the additive adsorption. - Abstract: Through Silicon Via (TSV) technology is essential to accomplish 3-dimensional packaging of electronics. Hence, more reliable and faster TSV filling by Cu electrodeposition is required. Our approach to improve Cu gap-filling in TSV is based on the development of new organic additives for feature filling. Here, we introduce our achievements from the synthesis of choline-based leveler to the feature filling using a synthesized leveler. The choline-based leveler, which includes two quaternary ammoniums at both ends of the molecule, is synthesized from glutaric acid. The characteristics of the choline-based additive are examined by the electrochemical analyses, and it is confirmed that the choline-based leveler shows a convection dependent adsorption behavior, which is essential for leveling. The interactions between the polymeric suppressor, accelerator, and the choline-based leveler are also investigated by changing the convection condition. Using the combination of suppressor, accelerator, and the choline-based leveler, the extreme bottom-up filling of Cu at trenches with dimensions similar to TSV are fulfilled. The mechanism of Cu gap-filling is demonstrated based on the results of electrochemical analyses and feature filling

  18. Comparison of GPS and Quaternary slip rates: Insights from a new Quaternary fault database for Central Asia

    Science.gov (United States)

    Mohadjer, Solmaz; Ehlers, Todd; Bendick, Rebecca; Mutz, Sebastian

    2016-04-01

    Previous studies related to the kinematics of deformation within the India-Asia collision zone have relied on slip rate data for major active faults to test kinematic models that explain the deformation of the region. The slip rate data, however, are generally disputed for many of the first-order faults in the region (e.g., Altyn Tagh and Karakorum faults). Several studies have also challenged the common assumption that geodetic slip rates are representative of Quaternary slip rates. What has received little attention is the degree to which geodetic slip rates relate to Quaternary slip rates for active faults in the India-Asia collision zone. In this study, we utilize slip rate data from a new Quaternary fault database for Central Asia to determine the overall relationship between Quaternary and GPS-derived slip rates for 18 faults. The preliminary analysis investigating this relationship uses weighted least squares and a re-sampling analysis to test the sensitivity of this relationship to different data point attributes (e.g., faults associated with data points and dating methods used for estimating Quaternary slip rates). The resulting sample subsets of data points yield a maximum possible Pearson correlation coefficient of ~0.6, suggesting moderate correlation between Quaternary and GPS-derived slip rates for some faults (e.g., Kunlun and Longmen Shan faults). Faults with poorly correlated Quaternary and GPS-derived slip rates were identified and dating methods used for the Quaternary slip rates were examined. Results indicate that a poor correlation between Quaternary and GPS-derived slip rates exist for the Karakorum and Chaman faults. Large differences between Quaternary and GPS slip rates for these faults appear to be connected to qualitative dating of landforms used in the estimation of the Quaternary slip rates and errors in the geomorphic and structural reconstruction of offset landforms (e.g., offset terrace riser reconstructions for Altyn Tagh fault

  19. Deposition of newly synthesized histones: new histones H2A and H2B do not deposit in the same nucleosome with new Histones H3 and H4

    International Nuclear Information System (INIS)

    Jackson, V.

    1987-01-01

    The authors have developed procedures to study histone-histone interactions during the deposition of histones in replicating cells. Cells are labeled for 60 min with dense amino acids, and subsequently, the histones within the nucleosomes are cross-linked into an octameric complex with formaldehyde. These complexes are sedimented to equilibrium in density gradients and octamer and dioctamer complexes separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. With reversal of the cross-link, the distribution of the individual density-labeled histones in the octamer is determined. Newly synthesized H3 and H4 deposits as a tetramer and are associated with old H2A and H2B. Newly synthesized H2A and H2B deposit as a dimer associated with old H2A, H2B, H3, and H4. The significance of these results with respect to the dynamics of histone interactions in the nucleus is discussed. Control experiments are presented to test for artifactual formation of these complexes during preparative procedures. In addition, reconstitution experiments were performed to demonstrate that the composition of these octameric complexes can be determined from their distribution of density gradients

  20. Fabrication of GaInPSb quaternary alloy nanowires and its room temperature electrical properties

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yadan; Ma, Liang; Li, Dan; Yang, Yankun; Wan, Qiang [Hunan University, School of Physics and Electronics, Changsha, Hunan (China); Liu, Ruping [Beijing Institute of Graphic Communication, Beijing (China); Dai, Guozhang [Central South University, School of Physics and Electronics, Changsha, Hunan (China)

    2017-01-15

    GaInPSb quaternary alloy nanowires were first synthesized via a simple chemical vapor deposition method. The synthesized nanowires' length can reach up to 20 μm and diameter ranging from 50 to 100 nm. Raman measurements and high-resolution transmission electron microscopy image illustrate that the as-grown nanowires have a high crystallinity. Room temperature near-infrared photodetector based on as-prepared GaInPSb nanowires was also built for the first time. It shows a good contact with the electrode, and the device has a strong light response to light illumination. This novel near-infrared photodetector may find promising applications in integrated infrared photodetection, information communication, and processing. (orig.)

  1. Global transgenerational gene expression dynamics in two newly synthesized allohexaploid wheat (Triticum aestivum lines

    Directory of Open Access Journals (Sweden)

    Qi Bao

    2012-01-01

    Full Text Available Abstract Background Alteration in gene expression resulting from allopolyploidization is a prominent feature in plants, but its spectrum and extent are not fully known. Common wheat (Triticum aestivum was formed via allohexaploidization about 10,000 years ago, and became the most important crop plant. To gain further insights into the genome-wide transcriptional dynamics associated with the onset of common wheat formation, we conducted microarray-based genome-wide gene expression analysis on two newly synthesized allohexaploid wheat lines with chromosomal stability and a genome constitution analogous to that of the present-day common wheat. Results Multi-color GISH (genomic in situ hybridization was used to identify individual plants from two nascent allohexaploid wheat lines between Triticum turgidum (2n = 4x = 28; genome BBAA and Aegilops tauschii (2n = 2x = 14; genome DD, which had a stable chromosomal constitution analogous to that of common wheat (2n = 6x = 42; genome BBAADD. Genome-wide analysis of gene expression was performed for these allohexaploid lines along with their parental plants from T. turgidum and Ae. tauschii, using the Affymetrix Gene Chip Wheat Genome-Array. Comparison with the parental plants coupled with inclusion of empirical mid-parent values (MPVs revealed that whereas the great majority of genes showed the expected parental additivity, two major patterns of alteration in gene expression in the allohexaploid lines were identified: parental dominance expression and non-additive expression. Genes involved in each of the two altered expression patterns could be classified into three distinct groups, stochastic, heritable and persistent, based on their transgenerational heritability and inter-line conservation. Strikingly, whereas both altered patterns of gene expression showed a propensity of inheritance, identity of the involved genes was highly stochastic, consistent with the involvement of diverse Gene Ontology (GO

  2. Essential oils-oriented fenvalerate analogues: syntheses, characterization and biological evaluation

    International Nuclear Information System (INIS)

    Su, H.; Li, H.

    2016-01-01

    A series of essential oils oriented ester derivatives have been designed, synthesized and characterized based on the skeleton of fenvalerate. The preliminary bioassay results indicated that some of the newly synthesized compounds showed better insecticidal activities against Pyrausta nubilalis and Heliothis armigera than that of the control trans-prallethrin chloride. (author)

  3. Designing Novel Quaternary Quantum Reversible Subtractor Circuits

    Science.gov (United States)

    Haghparast, Majid; Monfared, Asma Taheri

    2018-01-01

    Reversible logic synthesis is an important area of current research because of its ability to reduce energy dissipation. In recent years, multiple valued logic has received great attention due to its ability to reduce the width of the reversible circuit which is a main requirement in quantum technology. Subtractor circuits are between major components used in quantum computers. In this paper, we will discuss the design of a quaternary quantum reversible half subtractor circuit using quaternary 1-qudit, 2-qudit Muthukrishnan-Stroud and 3-qudit controlled gates and a 2-qudit Generalized quaternary gate. Then a design of a quaternary quantum reversible full subtractor circuit based on the quaternary half subtractor will be presenting. The designs shall then be evaluated in terms of quantum cost, constant input, garbage output, and hardware complexity. The proposed quaternary quantum reversible circuits are the first attempt in the designing of the aforementioned subtractor.

  4. Polydimethylsiloxane-polymethacrylate block copolymers tethering quaternary ammonium salt groups for antimicrobial coating

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Xiaoshuai; Li, Yancai; Zhou, Fang; Ren, Lixia; Zhao, Yunhui, E-mail: zhaoyunhui@tju.edu.cn; Yuan, Xiaoyan

    2015-02-15

    Highlights: • A series of PDMS-b-QPDMAEMA block copolymers were synthesized via RAFT polymerization. • The composition and morphology of the copolymer films strongly depended on the content of QPDMAEMA. • Migration of QPDMAEMA blocks toward surface was promoted when contacting with water. • Heterogeneous film surfaces with higher N{sup +} content exhibited more obvious antimicrobial activity. - Abstract: Block copolymers PDMS-b-PDMAEMA were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization involving N,N-dimethylaminoethyl methacrylate (DMAEMA) by using poly(dimethylsiloxane) (PDMS) macro-chain transfer agent. And, the tertiary amino groups in PDMAEMA were quaternized with n-octyliodide to provide quaternary ammonium salts (QPDMAEMA). The well-defined copolymers generated composition variation and morphology evolvement on film surfaces, which were characterized by X-ray photoelectron spectroscopy, atomic force microscopy, and contact angle measurements. The results indicated that the enrichment of QPDMAEMA brought about lower elemental ratios of Si/N on the film surfaces. The surface morphologies evolved with the variations of QPDMAEMA content, and the variation trend of film roughness was exactly opposite to that of water contact angle hysteresis. With regard to structure-antimicrobial relationships, the copolymer films had more evident antimicrobial activity against Gram-positive, Bacillus subtilis, and the surfaces with heterogeneous morphology and higher N{sup +} content presented better antimicrobial activity. The functionalized copolymers based PDMS and quaternary ammonium salts materials have the potential applications as antimicrobial coatings.

  5. Multi-wavelength spectrophotometric determination of acidity constant of some newly synthesized Schiff bases and their QSPR study

    Science.gov (United States)

    Hemmateenejad, Bahram; Emami, Leila; Sharghi, Hashem

    2010-01-01

    The acidity constants of some newly synthesized Schiff base derivatives were determined by hard-model based multivariate data analysis of the spectrophotometric data in the course of pH-metric titration in 50% (v/v) methanol-water binary solvent. The employed data analysis method was also able to extract the pure spectra and pH-dependent concentration profiles of the acid-base species. The molecules that possess different substituents (both electron donating and withdrawing) on the ortho-, meta- and para-positions of one of the phenyl ring showed variable acidity constants ranging from 8.77 to 11.07 whereas the parent molecule had an acidity constant of 10.25. To investigate the quantitative effects of changing of substitution pattern on the acidity constant, a quantitative structure-property relation analysis was conducted using substituent constants and molecular descriptor. Some models with high statistical quality (measured by cross-validation Q2) were obtained. It was found that the acidity constant of the studied molecules in the methanol-water mixed solvent not only is affected by electronic features of the solutes but also by the lipophilic interaction between methanol part of solvent and the deprotonated solutes.

  6. Formation of newly synthesized adeno-associated virus capsids in the cell nucleus.

    Science.gov (United States)

    Bell, Peter; Vandenberghe, Luk H; Wilson, James M

    2014-06-01

    Adeno-associated virus (AAV) particles inside the nucleus of a HEK 293 cell are shown by electron microscopy. Cells have been triple-transfected for vector production and were analyzed for capsid formation three days later. Newly assembled particle are visible as seemingly unstructured conglomerates or crystal-like arrays.

  7. Optical analysis of lens-like Cu{sub 2}CdSnS{sub 4} quaternary alloy nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Odeh, Ali Abu; Ayub, R.M. [University Malaysia Perlis, Institute of Nano Electronic Engineering, Kangar, Perlis (Malaysia); Al-Douri, Y. [University Malaysia Perlis, Institute of Nano Electronic Engineering, Kangar, Perlis (Malaysia); University of Sidi-Bel-Abbes, Physics Department, Faculty of Science, Sidi-Bel-Abbes (Algeria); Ameri, M. [Universite Djilali Liabes de Sidi Bel- Abbes, Laboratoire Physico-Chimie des Materiaux Avances (LPCMA), Sidi-Bel-Abbes (Algeria); Bouhemadou, A. [University of Setif 1, Laboratory for Developing New Materials and Their Characterization, Setif (Algeria); Prakash, Deo [SMVD University, Faculty of Engineering, School of Computer Science and Engineering, Kakryal, Katra, J and K (India); Verma, K.D. [S.V. College, Material Science Research Laboratory, Department of Physics, Aligarh, U.P. (India)

    2016-10-15

    Cu{sub 2}CdSnS{sub 4} quaternary alloy nanostructures with different copper concentrations (0.2, 0.4, 0.6, 0.8 and 1.0 M) were successfully synthesized on n-type silicon substrates using spin coating technique with annealing temperature at 300 C. Optical properties were analyzed through UV-Vis and Photoluminescence spectroscopies, and thus, there is a change in energy band gap with increasing Cu concentration from 0.2 to 1.0 M. The structural properties of Cu{sub 2}CdSnS{sub 4} quaternary alloy nanostructures were investigated by X-ray diffraction. The particles size and shape have a direct relationship with copper concentration. Morphological and topographical studies were carried out by using scanning electron microscopy and atomic force microscopy. The obtained results are investigated to be available in the literature for future studies. (orig.)

  8. Synthesis, Spectroscopic and Theoretical Studies of New Quaternary N,N-Dimethyl-3-phthalimidopropylammonium Conjugates of Sterols and Bile Acids

    Directory of Open Access Journals (Sweden)

    Bogumil Brycki

    2014-04-01

    Full Text Available New quaternary 3-phthalimidopropylammonium conjugates of steroids were obtained by reaction of sterols (ergosterol, cholesterol, cholestanol and bile acids (lithocholic, deoxycholic, cholic with bromoacetic acid bromide to give sterol 3β-bromoacetates and bile acid 3α-bromoacetates, respectively. These intermediates were subjected to nuclephilic substitution with N,N-dimethyl-3-phthalimidopropylamine to give the final quaternary ammonium salts. The structures of products were confirmed by spectral (1H-NMR, 13C-NMR, and FT-IR analysis, mass spectrometry (ESI-MS, MALDI as well as PM5 semiempirical methods and B3LYP ab initio methods. Estimation of the pharmacotherapeutic potential has been accomplished for synthesized compounds on the basis of Prediction of Activity Spectra for Substances (PASS.

  9. Fibronectin-synthesizing activity of free and membrane-bound polyribosomes from human embryonic fibroblasts and chick embryos

    International Nuclear Information System (INIS)

    Belkin, V.M.; Volodarskaya, S.M.

    1986-01-01

    The fibronectin-synthesizing activity of membrane-bound and free polyribosomes in a cell-free system was studied using immunochemical methods. It was found that fibronectin biosynthesis on membrane-bound polyribosomes from human embryonic fibroblasts accounts for 4.9% and those from 10-day-old chick embryos for 1.1% of the total amount of newly synthesized proteins, whereas on free polyribosomes it is 1.0 and 0.3%, respectively. Fibronectin monomers with a molecular weight of 220,000 were found only in the material of the cell-free system containing heavy fractions of membrane-bound polyribosomes newly synthesized in the presence of spermidine. Thus, it was shown that fibronectin is synthesized primarily on membrane-bound polyribosomes

  10. Quaternary fault in Hwalseong-ri, Oedong-up, Gyeongju, Korea.

    Energy Technology Data Exchange (ETDEWEB)

    Ryoo, Chung-Ryul; Chwae, Uee-Chan; Choi, Sung-Ja [Korea Institute of Geoscience and Mineral Resources, Taejeon(Korea); Son, Moon [Pusan National University, Pusan(Korea)

    2001-09-01

    We describe a Quaternary fault occurring in Hwalseong-ri, Oedong-up, Gyeongju in the eastern part of Ulsan Fault Zone, Korea. This fault (Hwalseongri Fault) is developed around the contact between the early Tertiary granite and the Quaternary gravel layer. Four different faults are distinguished from west to east: (1) fault within Quaternary gravel layer, (2) fault between Quaternary gravel layer and granite, (3) fault between Quaternary gravel layer overlying granite and granite, (4) fault between granite and Quaternary layer. General strike of the fault zone vary from NNW to NE, dipping to east. Two striations, E-W and N-S, are developed. The former is related mainly to the reverse faulting, and the latter to the sinistral shearing. This fault zone was reactivated, and considered as a positive flower structure mainly by the results of the E-W compression in the southeastern part of the Korean Peninsula during Quaternary. (author). 45 refs., 6 figs.

  11. Novel Evaporation Process for Deposition of Kesterite Thin Films Synthesized by Solvothermal Method

    Directory of Open Access Journals (Sweden)

    J. A. Estrada-Ayub

    2017-01-01

    Full Text Available Kesterite, a quaternary compound of Cu2ZnSnS4, is a promising option as a material absorber to reduce the cost of photovoltaic solar cells. The solvothermal method is a way to synthesize nanoparticles of this material. In this work, once synthesized, particles were deposited on a substrate through evaporation, and their morphological, structural, and optical properties were studied. Results show that changes of precursor ratios during solvothermal synthesis result in a modification of particle morphology but not on its size. The deposition of already synthesized kesterite through evaporation preserves kesterite structure and permits the formation of a homogenous film on a substrate. Optical reflectance and transmittance measurements allowed estimating the band-gap energy between 1.41 and 1.46 eV for representative samples, which is near the optimum for the absorber material.

  12. Low Pt content Pt-Ru-Ir-Sn quaternary catalysts for anodic methanol oxidation in DMFC

    Energy Technology Data Exchange (ETDEWEB)

    Neburchilov, Vladimir; Wang, Haijiang; Zhang, Jiujun [Institute for Fuel Cell Innovation, National Research Council (Canada)

    2007-07-15

    In this communication we report our research work on low Pt content Pt-Ru-Ir-Sn quaternary catalysts for use in DMFC anodes. The carbon-supported quaternary metal alloy catalyst was synthesized according to the solution reduction method and was deposited onto a carbon fiber paper or a carbon aerogel nanofoam to form the anode for direct methanol fuel cells. The Pt loading of the electrode is 0.1 mg/cm{sup 2}. The testing results from a three-electrode electrochemical cell show that the simultaneous use of higher Ir (25-35 wt.%) and Sn (10 wt.%) content gives satisfactory stability and higher activity for methanol oxidation than the commercially available E-TEK anode (80%[0.5Pt 0.5Ru]/C on carbon cloth). Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), scanning electron microscope (SEM), and Bruner-Emmett-Teller method (BET) measurements were carried out to characterize the composition, structure, morphology, and surface area of the developed catalysts. (author)

  13. Quaternary palaeoceanography and palaeogeography in Northern Denmark

    DEFF Research Database (Denmark)

    Knudsen, Karen Luise; Conradsen, Keld; Heier‐Nielsen, Susanne

    1996-01-01

    Palaeoenvironmental reconstructions from the Skagen record contribute to the understanding of Late Quaternary climatic changes and variations in the oceanographic circulation pattern in the entire North Atlantic region. The Skagen cores penetrated c. 192 m of Quaternary sediments comprising two...... the Holocene, including the Pleistocene-Holocene transition. Results from the study of lithology, foraminifera, stable isotope measurements and radiocarbon dates are reviewed while emphasizing the most important contributions to the general understanding of the North Atlantic Quaternary history....

  14. Physical, chemical and antimicrobial evaluation of a composite material containing quaternary ammonium salt for braces cementation

    International Nuclear Information System (INIS)

    Sugii, Mari Miura; Ferreira, Fábio Augusto de Souza; Müller, Karina Cogo; Lima, Debora Alves Nunes Leite; Groppo, Francisco Carlos; Imasato, Hidetake; Rodrigues-Filho, Ubirajara Pereira

    2017-01-01

    The antibiofilm effect of iodide quaternary ammonium methacryloxy silicate (IQAMS) in Transbond XT Light Cure Adhesive resin used for braces cementation was evaluated. Fourier Transform Infrared (FTIR) spectroscopy confirmed IQAMS formation and Scanning Electron Microscopy coupled to Energy-Dispersive X-ray Spectroscopy (SEM-EDS) revealed that as coating, the quaternary ammonium groups from IQAMS were homogeneously dispersed throughout the surface. When incorporated, the composite material presented homogeneous dispersion throughout the resin. Assays with Streptococcus mutans demonstrated enhanced antibiofilm effect for the IQAMS coated resin, with much lower colony-forming units (CFU), in comparison to incorporated IQAMS. Such a difference was assigned to low availability of quaternary ammonium groups at the surface of resin when IQAMS was incorporated, hindering its antibiofilm effect. Additionally, the incorporation of IQAMS led to slight decrease in ultimate bond strength (UBS) and shear bond strength (SBS), in comparison to the neat commercial resin. Thus, the synthesized IQAMS displays great potential as antibiofilm coating or sealant to prevent oral infections in brackets during orthodontic treatment. - Highlights: • Synthesis of ORMOSIL-based material with antibiofilm activity is performed. • Antibiofilm activity of the ORMOSIL-based material on commercial available resin for braces cementation is evaluated. • Antibiofilm ORMOSIL-based coating with potential application as varnish or sealant in orthodontic appliances is presented.

  15. Physical, chemical and antimicrobial evaluation of a composite material containing quaternary ammonium salt for braces cementation

    Energy Technology Data Exchange (ETDEWEB)

    Sugii, Mari Miura [Departamento de Odontologia Restaurativa, Faculdade de Odontologia de Piracicaba – Universidade de Campinas, Piracicaba, SP 13414-903 (Brazil); Ferreira, Fábio Augusto de Souza, E-mail: ferreira.fabio.a.s@gmail.com [Grupo de Química de Materiais Híbridos e Inorgânicos, Instituto de Química de São Carlos – Universidade de São Paulo, São Carlos, SP 13563-120 (Brazil); Müller, Karina Cogo [Departamento de Ciências Fisiológicas, Área de Farmacologia, Anestesiologia e Terapeutica, Faculdade de Odontologia de Piracicaba – Universidade de Campinas, Piracicaba, SP 13414-903 (Brazil); Lima, Debora Alves Nunes Leite [Departamento de Odontologia Restaurativa, Faculdade de Odontologia de Piracicaba – Universidade de Campinas, Piracicaba, SP 13414-903 (Brazil); Groppo, Francisco Carlos [Departamento de Ciências Fisiológicas, Área de Farmacologia, Anestesiologia e Terapeutica, Faculdade de Odontologia de Piracicaba – Universidade de Campinas, Piracicaba, SP 13414-903 (Brazil); Imasato, Hidetake; Rodrigues-Filho, Ubirajara Pereira [Grupo de Química de Materiais Híbridos e Inorgânicos, Instituto de Química de São Carlos – Universidade de São Paulo, São Carlos, SP 13563-120 (Brazil); and others

    2017-04-01

    The antibiofilm effect of iodide quaternary ammonium methacryloxy silicate (IQAMS) in Transbond XT Light Cure Adhesive resin used for braces cementation was evaluated. Fourier Transform Infrared (FTIR) spectroscopy confirmed IQAMS formation and Scanning Electron Microscopy coupled to Energy-Dispersive X-ray Spectroscopy (SEM-EDS) revealed that as coating, the quaternary ammonium groups from IQAMS were homogeneously dispersed throughout the surface. When incorporated, the composite material presented homogeneous dispersion throughout the resin. Assays with Streptococcus mutans demonstrated enhanced antibiofilm effect for the IQAMS coated resin, with much lower colony-forming units (CFU), in comparison to incorporated IQAMS. Such a difference was assigned to low availability of quaternary ammonium groups at the surface of resin when IQAMS was incorporated, hindering its antibiofilm effect. Additionally, the incorporation of IQAMS led to slight decrease in ultimate bond strength (UBS) and shear bond strength (SBS), in comparison to the neat commercial resin. Thus, the synthesized IQAMS displays great potential as antibiofilm coating or sealant to prevent oral infections in brackets during orthodontic treatment. - Highlights: • Synthesis of ORMOSIL-based material with antibiofilm activity is performed. • Antibiofilm activity of the ORMOSIL-based material on commercial available resin for braces cementation is evaluated. • Antibiofilm ORMOSIL-based coating with potential application as varnish or sealant in orthodontic appliances is presented.

  16. Nano-sized quaternary CuGa2In3S8 as an efficient photocatalyst for solar hydrogen production

    KAUST Repository

    Kandiel, Tarek

    2014-09-03

    The synthesis of quaternary metal sulfide (QMS) nanocrystals is challenging because of the difficulty to control their stoichiometry and phase structure. Herein, quaternary CuGa2In3S8 photocatalysts with a primary particle size of ≈4nm are synthesized using a facile hot-injection method by fine-tuning the sulfur source injection temperature and aging time. Characterization of the samples reveals that quaternary CuGa2In3S8 nanocrystals exhibit n-type semiconductor characteristics with a transition band gap of ≈1.8eV. Their flatband potential is located at -0.56V versus the standard hydrogen electrode at pH6.0 and is shifted cathodically by 0.75V in solutions with pH values greater than 12.0. Under optimized conditions, the 1.0wt% Ru-loaded CuGa2In3S8 photocatalyst exhibits a photocatalytic H2 evolution response up to 700nm and an apparent quantum efficiency of (6.9±0.5)% at 560nm. These results indicate clearly that QMS nanocrystals have great potential as nano-photocatalysts for solar H2 production. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Fabrication of copper-selective PVC membrane electrode based on newly synthesized copper complex of Schiff base as carrier

    Directory of Open Access Journals (Sweden)

    Sulekh Chandra

    2016-09-01

    Full Text Available The newly synthesized copper(II complex of Schiff base p-hydroxyacetophenone semicarbazone was explored as neutral ionophore for the fabrication of poly(vinylchloride (PVC based membrane electrode selective to Cu(II ions. The electrode shows a Nernstian slope of 29.8 ± 0.3 mV/decade with improved linear range of 1.8 × 10−7 to 1.0 × 10−1 M, comparatively lower detection limit 5.7 × 10−8 M between pH range of 2.0–8.0, giving a relatively fast response within 5s and can be used for at least 16 weeks without any divergence in potential. The selectivity coefficient was calculated using the fixed interference method (FIM. The electrode can also be used in partially non-aqueous media having up to 25% (v/v methanol, ethanol or acetone content with no significant change in the value of slope or working concentration range. It was successfully applied for the direct determination of copper content in water and tea samples with satisfactory results. The electrode has been used in the potentiometric titration of Cu2+ with EDTA.

  18. Phase study in Sr-Th-P-O system: Structural and thermal investigations of quaternary compounds

    International Nuclear Information System (INIS)

    Keskar, Meera; Phatak, Rohan; Sali, S.K.; Krishnan, K.; Dahale, N.D.; Kulkarni, N.K.; Kannan, S.

    2011-01-01

    The sub-solidus phase relations in Sr-Th-P-O quaternary system were determined at 1223 K in air. To confirm the formation and stability of reported phases, ternary and quaternary compounds in Sr-Th-O, Sr-P-O, Th-P-O and Sr-Th-P-O systems were synthesized by solid state reactions of SrCO 3 , ThO 2 and NH 4 H 2 PO 4 in desired molar proportions at 1223 K. A pseudo-ternary phase diagram of SrO-ThO 2 -P 2 O 5 system was drawn on the basis of the phase analysis of various phase mixtures and phase fields were established by powder X-ray diffraction. In the phase diagram, three quaternary compounds SrTh(PO 4 ) 2 , SrTh 4 (PO 4 ) 6 and Sr 7 Th(PO 4 ) 6 were identified. When heated in air at 1673 K, these compounds decompose to ThO 2 . Structures of SrTh(PO 4 ) 2 , SrTh 4 (PO 4 ) 6 and Sr 7 Th(PO 4 ) 6 were derived from X-ray powder data using the Rietveld refinement method. Thermal expansion behaviors of SrTh(PO 4 ) 2 , SrTh 4 (PO 4 ) 6 and Sr 7 Th(PO 4 ) 6 were investigated using high-temperature X-ray diffraction in the temperature range of 298-1273 K.

  19. Random quaternary ammonium Diels-Alder poly(phenylene) copolymers for improved vanadium redox flow batteries

    Science.gov (United States)

    Largier, Timothy D.; Cornelius, Chris J.

    2017-06-01

    This study analyzes the effect of quaternary ammonium homopolymer (AmPP) and ionic and non-ionic random unit copolymerization (AmPP-PP) of Diels-Alder poly(phenylene)s on electrochemical and transport properties, vanadium redox flow battery performance, and material stability. AmPP-PP materials were synthesized with IEC's up to 2.2 meq/g, displaying a carbonate form ion conductivity of 17.3 mS/cm and water uptake of 57.3%. Vanadium ion permeability studies revealed that the random copolymers possess superior charge carrier selectivity. For materials of comparable ion content, at 10 mA/cm2 the random copolymer displayed a 14% increase in coulombic efficiency (CE) corresponding to a 7% increase in energy efficiency. All quaternary ammonium materials displayed ex situ degradation in a 0.5 M V5+ + 5 M H2SO4 solution, with the rate of degradation appearing to increase with IEC. Preliminary studies reveal that the neutralizing counter-ion has a significant effect on VRB performance, proportional to changes in vanadium ion molecular diffusion.

  20. Synthesis of Zeolite from Fly Ash and Removal of Heavy Metal Ions from Newly Synthesized Zeolite

    OpenAIRE

    Solanki, Parag; Gupta, Vikal; Kulshrestha, Ruchi

    2010-01-01

    Coal fly ash was used to synthesize X-type zeolite by alkali fusion followed by hydrothermal treatment. Characteristics of the various Fly ash samples were carried out. Coal proximate analysis was done. Batch experiment was carried out for the adsorption of some heavy metal ions on to synthesized Zeolite. The cost of synthesized zeolite was estimated to be almost one-fifth of that of commercial 13X zeolite available in the market.

  1. Unstable structure of ribosomal particles synthesized in. gamma. -irradiated Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, H; Morita, K [National Inst. of Radiological Sciences, Chiba (Japan)

    1975-06-01

    Stability of Escherichia coli ribosomes newly synthesized after ..gamma..-irradiation was compared with that of normal ribosomes. The ribosomal particles around 70-S synthesized in irradiated cells were more sensitive to digestion by pancreatic ribonuclease A. A larger number of the salt-unstable '50-S' precursor particles existed in the extract from irradiated cells than in the extract from unirradiated cells. These facts suggest that ribosomal particles, synthesized during an earlier stage in irradiated cells, maintain an incomplete structure even though they are not distinguishable from normal ribosomes by means of sucrose density-gradient centrifugation.

  2. Quaternary ammonium-functionalized MCM-48 mesoporous silica as a sorbent for the dispersive solid-phase extraction of endocrine disrupting compounds in water.

    Science.gov (United States)

    Zhang, Shijuan; Lu, Fengli; Ma, Xiaoyun; Yue, Mingbo; Li, Yanxin; Liu, Jiammin; You, Jinmao

    2018-07-06

    MCM-48 mesoporous silica was functionalized with dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, a quaternary ammonium salt with a long hydrophobic chain, to prepare a new sorbent for the dispersive solid-phase extraction (DSPE) of seven endocrine disrupting compounds (EDCs) including 4-hexylphenol, 4-octylphenol, 4-nonylphenol, bisphenol A, estrone, 17β-estradiol and estriol in water. A series of differently functionalized MCM-48 materials were also synthesized, and they served as reference materials to study the mechanism. The developed DSPE method was combined with HPLC with fluorescence detection to evaluate the adsorption performance. The results indicated that the quaternary ammonium-functionalized MCM-48 mesoporous silica can be used as ideal sorbent for EDCs in water with recoveries of higher than 95% due to the electrostatic interactions and hydrophobic effect. Hydrogen bonding and π-π interactions in other synthesized materials could lead to about 25-30% increase in recoveries, but the results for polyhydroxy compounds were still not satisfying. The quaternary ammonium-functionalized MCM-48 mesoporous silica was successfully applied to the DSPE of EDCs in real water samples. The optimum extraction conditions were sorbent amount, 15 mg; desorption time; 5 min; elution volume, 0.8 mL; sample pH 3.0; and salt addition, 5 g/L. The limits of detection were in the range of 1.2-2.6 ng/L, while the limits of quantitation were in the range of 4.3-8.3 ng/L. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Structural and optical properties of alloyed quaternary CdSeTeS core and CdSeTeS/ZnS core–shell quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Adegoke, Oluwasesan, E-mail: adegoke.sesan@mailbox.co.za [Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Lynnwood Road, Pretoria 0002 (South Africa); Nyokong, Tebello, E-mail: t.nyokong@ru.ac.za [Department of Chemistry, Rhodes University, Grahamstown 6140 (South Africa); Forbes, Patricia B.C., E-mail: patricia.forbes@up.ac.za [Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Lynnwood Road, Pretoria 0002 (South Africa)

    2015-10-05

    Highlights: • Alloyed quaternary CdSeTeS core quantum dots (QDs) were synthesized. • Passivation was carried out using a ZnS shell. • Quaternary CdSeTeS core exhibited unique optical properties over CdSeTe/ZnS. • CdSeTeS can be employed as a useful alternative to core/shell QDs. - Abstract: Synthesis of fluorescent alloyed quantum dots (QDs) with unique optical properties suitable for a wide array of chemical, physical and biological applications is of research interest. In this work, highly luminescent and photostable alloyed quaternary CdSeTeS core QDs of two different sizes were fabricated via the organometallic hot-injection synthetic route. Characterization of the nanocrystals were performed using TEM, XRD, UV/vis and fluorescence spectrophotometric techniques. We have demonstrated in this work that the well fabricated alloyed quaternary CdSeTeS core QDs possess unique optical properties that are advantageous over conventional core/shell systems. Formation of the CdSeTeS/ZnS core/shell with the desired optical properties comes with a number of challenges, hence the advantages of the quaternary alloyed core over the core/shell QDs are (i) avoidance of the challenging process of determining the proper shell thickness which can provide the desired optical properties in the core/shell system and (ii) avoidance of the lattice-induced mismatch between the core and the shell material which can either lead to incomplete exciton confinement or dislocation at the core/shell interface.

  4. A Quaternary Polybenzimidazole Membrane for Intermediate Temperature Polymer Electrolyte Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Xu, C.; Scott, K.; Li, Qingfeng

    2013-01-01

    at 150 °C with the PA acid loading level of 3.5 PRU (amount of H3PO4 per repeat unit of polymer QPBI). The QPBI membrane was characterized in terms of composition, structure and morphology by NMR, FTIR, SEM, and EDX. The fuel cell performance with the membrane gave peak power densities of 440 and 240 m......A quaternary ammonium polybenzimidazole (QPBI) membrane was synthesized for applications in intermediate temperature (100–200 °C) hydrogen fuel cells. The QPBI membrane was imbibed with phosphoric acid to provide suitable proton conductivity. The proton conductivity of the membrane was 0.051 S cm–1......W cm–2 using oxygen and air, respectively, at 175 °C....

  5. Measurement and study of density, surface tension, and viscosity of quaternary ammonium-based ionic liquids ([N222(n)]Tf2N)

    International Nuclear Information System (INIS)

    Ghatee, Mohammad Hadi; Bahrami, Maryam; Khanjari, Neda

    2013-01-01

    Highlights: • Characterization of high purity synthesized alkyl quaternary ammonium ionic liquids. • Measurement of temperature dependent surface tension, density, viscosity and critical point. • Systematic increase of surface energy and surface entropy having plateau at high chain length. • Accurate application of VFT and fluidity equations to temperature dependent viscosities. • Particular variation of fluidity exponent with a plateau at high alkyl chain length. -- Abstract: In this work five quaternary ammonium-based ionic liquids with bis(trifluoromethylsulfonyl)imide anion were synthesized and their density, viscosity and surface tensions were measured in the temperature range (298 to 373) K. Surface tensions were measured by capillary rise method using a homemade capillary apparatus, in which the liquid/vapor can be brought into equilibrium practically. Measurements of viscosities and surface tensions were performed under water–vapor free atmosphere. The surface tension of quaternary ammonium-based ILs decreases as the alkyl chain length increases. Also surface energy and surface entropy are found as increasing functions of alkyl chain length with a plateau at high lengths in the surface. The viscosities measured by capillary viscometer fit in VFT equation, indication of non-Arrhenius ionic liquids. Viscosities are also fitted quite accurately in the relation we have developed recently as the fluidity equation with the characteristics exponent ϕ. Values of ϕ for ionic liquids are close to one another and tend to the limiting value, almost 0.328, asymptotically as the alkyl chain length increases. The critical temperatures predicted via the temperature dependent surface tensions decrease with increasing alkyl chain length of the cation. The trend of predicted critical temperature of these ionic liquids conforms to those of imidazolium-based ILs

  6. Doxycycline and its quaternary ammonium derivative for adjuvant therapies of chondrosarcoma.

    Science.gov (United States)

    Miladi, Imen; Vivier, Magali; Dauplat, Marie-Mélanie; Chatard, Morgane; Besse, Sophie; Vidal, Aurélien; Chassain, Karine; Jean, Betty; Forestier, Christiane; Chezal, Jean-Michel; Rédini, Francoise; Degoul, Francoise; Miot-Noirault, Elisabeth

    2017-09-01

    This study was conducted during the development of innovative treatment targeting the microenvironment of chondrosarcoma. In this context, MMP inhibitors were conjugated with a quaternary ammonium (QA) function as a targeting ligand to proteoglycans of chondrosarcoma extracellular matrix. Here we report the proof of concept of this strategy applied to the MMP13 inhibitor, doxycycline (Dox). A quaternary ammonium derivative of the MMP13 inhibitor doxycycline (QA-Dox) was synthesized, and its anticancer activity was evaluated in the Swarm rat chondrosarcoma (SRC) model compared with the parent drug doxycycline, in vitro and in vivo. In vivo, dox and QA-Dox efficiency was assessed at equimolar doses according to a q4dx4 schedule by monitoring tumour volume by MRI and PG-targeted scintigraphy. Molecular mechanism (MMP13 expression, proteoglycan level) and histology studies were performed on tumours. The link of QA targeting function to Dox maintained the MMP13 inhibitory activity in vitro. Interestingly, the bacteriostatic activity was lost. SRC cells incubated with both drugs were blocked in S and G2 M phases. Tumour growth inhibition (confirmed by histology) was observed for both Dox and QA-Dox. Undesirable blood effects (leukocyte decrease) were reduced when Dox was targeted to tumour tissue using the QA function. In the SRC model, the MMP13 inhibitor Dox and its QA derivative are promising as adjuvant therapies for chondrosarcoma management.

  7. PRN 88-2: Clustering of Quaternary Ammonium Compounds

    Science.gov (United States)

    This Notice announces that EPA has clustered the Quaternary Ammonium Compounds into four groups for the purpose of testing chemicals to build a database that will support continued registration of the entire family of quaternary ammonium compounds

  8. Syntheses and characterization of novel oxoisoaporphine derivatives as dual inhibitors for cholinesterases and amyloid beta aggregation.

    Science.gov (United States)

    Li, Yan-Ping; Ning, Fang-Xian; Yang, Meng-Bi; Li, Yong-Cheng; Nie, Min-Hua; Ou, Tian-Miao; Tan, Jia-Heng; Huang, Shi-Liang; Li, Ding; Gu, Lian-Quan; Huang, Zhi-Shu

    2011-05-01

    A series of 3-substituted (5c-5f, 6c-6f) and 4-substituted (10a-10g) oxoisoaporphine derivatives were synthesized. It was found that all these synthetic compounds had IC50 values at micro or nano molar range for cholinesterase inhibition, and most of them could inhibit amyloid β (Aβ) self-induced aggregation with inhibition ratio from 31.8% to 57.6%. The structure-activity relationship studies revealed that the derivatives with higher selectivity on AChE also showed better inhibition on Aβ self-induced aggregation. The results from cell toxicity study indicated that most quaternary methiodide salts had higher IC50 values than the corresponding non-quaternary compounds. This study provided potentially important information for further development of oxoisoaporphine derivatives as lead compounds for the treatment of Alzheimer's disease. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  9. Climate predictors of late quaternary extinctions

    DEFF Research Database (Denmark)

    Nogués-Bravo, David; Ohlemüller, Ralf; Batra, Persaram

    2010-01-01

    Between 50,000 and 3,000 years before present (BP) 65% of mammal genera weighing over 44 kg went extinct, together with a lower proportion of small mammals. Why species went extinct in such large numbers is hotly debated. One of the arguments proposes that climate changes underlie Late Quaternary...... extinctions, but global quantitative evidence for this hypothesis is still lacking. We test the potential role of global climate change on the extinction of mammals during the Late Quaternary. Our results suggest that continents with the highest climate footprint values, in other words, with climate changes...... of greater magnitudes during the Late Quaternary, witnessed more extinctions than continents with lower climate footprint values, with the exception of South America. Our results are consistent across species with different body masses, reinforcing the view that past climate changes contributed to global...

  10. Synthesis, Crystal and Electronic Structure of the Quaternary Magnetic EuTAl4Si2 (T = Rh and Ir) Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, Arvind [Tata Institute of Fundamental Research; Thamizhavel, Arumugam [Tata Institute of Fundamental Research; Provino, Alessia [University of Genova; Pani, Marcella [University of Genova; Manfrinetti, Pietro [University of Genova; Paudyal, Durga [Ames Laboratory; Dhar, Sudesh Kumar [Tata Institute of Fundamental Research

    2014-01-22

    Single crystals of the quaternary europium compounds EuRhAl4Si2 and EuIrAl4Si2 were synthesized by using the Al–Si binary eutectic as a flux. The structure of the two quaternary compounds has been refined by single crystal X-ray diffraction. Both compounds are stoichiometric and adopt an ordered derivative of the ternary KCu4S3 structure type (tetragonal tP8, P4/mmm). The two compounds reported here represent the first example of a quaternary and truly stoichiometric 1:1:4:2 phase crystallizing with this structure type. In light of our present results, the structure of the BaMg4Si3 compound given in literature as representing a new prototype is actually isotypic with the KCu4S3 structure. Local spin density approximation including the Hubbard U parameter (LSDA + U) calculations show that Eu ions are in the divalent state, with a significant hybridization between the Eu 5d, Rh (Ir) 4d (5d), Si 3p and Al 3p states. Magnetic susceptibility measured along the [001] direction confirms the divalent nature of the Eu ions in EuRhAl4Si2 and EuIrAl4Si2, which order magnetically near 11 and 15 K, respectively.

  11. Supramolecular assembly of borate with quaternary ammonium: Crystal structure and tunable luminescent properties

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Jie; Wang, Yong-gang [Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Wang, Ying-xia, E-mail: wangyx@pku.edu.cn [Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Liao, Fu-hui [Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Lin, Jian-hua, E-mail: jhlin@pku.edu.cn [Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

    2013-04-15

    A new borate [C{sub 6}H{sub 16}N][B{sub 5}O{sub 6}(OH){sub 4}] (1) is synthesized hydrothermally by the reaction of isopropyltrimethylammonium hydroxide with boric acid. It crystallizes in the triclinic space group P-1 with the parameters a=9.1578(10) Å, b=9.372(9) Å, c=9.9812(10) Å, α=66.508(2)°, β=74.751(2)°, γ=81.893(2)°. The [B{sub 5}O{sub 6}(OH){sub 4}]{sup −} anions are interlinked via hydrogen bonding forming a 3D supramolecular network containing large cavities, where reside the (CH{sub 3}){sub 3}(i-C{sub 3}H{sub 7}) N{sup +} cations. This borate shows tunable luminescent properties with temperature, heating-treatment, exciting-light, and solvents. The fluorescent intensity of 1 enhances 6-fold with decreasing the temperature from 25 K to 78 K. By treatment under different temperatures, the luminescence of 1 shifted from blue to white and the sample treated at 230 °C emits bright white light to naked eyes. The hybrid borate can disperse in different solvents, and shows a red-shifted and intense emission in polar solvents. - Graphical abstract: The new quaternary ammonium borate [C{sub 6}H{sub 17}N][B{sub 5}O{sub 6}(OH){sub 4}] contains a 3D supramolecular network formed by hydrogen bond linked [B{sub 5}O{sub 6}(OH){sub 4}]{sup −} anions and shows tunable luminescent properties with temperature, excitation light, and solvents. Highlights: ► A novel quaternary ammonium borate was synthesized. ► It possesses a supramolecular network fomed by H-bonded [B{sub 5}O{sub 6}(OH){sub 4}]{sup −} anions. ► This borate shows tunable luminescent properties with temperature, heating treatment, excitation light, and solvents.

  12. Investigation of formation constant of complex of a new synthesized ...

    African Journals Online (AJOL)

    The complex formation between a newly synthesized tripodal ligand and the cation Cu2+ in water and surfactant media was studied spectrophotometrically using rank annihilation factor analysis (RAFA). According to molar ratio data the stoichiometry of complexation between the ligand and the cation Cu2+ was 1:1.

  13. Newly synthesized bis-benzimidazole compound 8 induces apoptosis, autophagy and reactive oxygen species generation in HeLa cells.

    Science.gov (United States)

    Chu, Naying; Yao, Guodong; Liu, Yuan; Cheng, Maosheng; Ikejima, Takashi

    2016-09-01

    Compound 8 (C8) is a newly synthesized bis-benzimidazole derivative and exerts significant anti-tumor activity in vitro. Previous studies demonstrated that C8 induced apoptosis and autophagy in human promyelocytic leukemia HL60 cells. However, cytotoxicity study on human peripheral blood mononuclear cells (hPBMC) showed that C8 exhibited less toxicity in normal cells. In this study, the molecular mechanism of C8 on human cervical carcinoma HeLa cells was investigated. The results showed that C8 inhibited the growth of HeLa cells and triggered both apoptotic and autophagic cell death. Subsequent experiment also indicated that reactive oxygen species (ROS) generation was induced in C8-treated HeLa cells. Since ROS scavenger decreased the ratio of apoptotic and autophagic cells, ROS generation contributed to C8-induced apoptosis and autophagy. Furthermore, inhibitors of apoptosis and autophagy also reduced ROS generation, respectively. Autophagy inhibition increased cell growth compared to C8-treated group and attenuated apoptotic cell death, indicating that C8-induced autophagy promoted apoptosis for cell death. However, the percentage of autophagic cells was enhanced when limiting apoptosis process. Taken together, C8 induced ROS-mediated apoptosis and autophagy in HeLa cells, autophagy promoted apoptosis but the former was antagonized by the latter. The data also gave us a new perspective on the anti-tumor effect of C8. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Thermotropic phase transitions of catanionic dodecylsulfates with multi-charged and multi-tailed quaternary ammonium centers

    Energy Technology Data Exchange (ETDEWEB)

    Mihelj, Tea, E-mail: tmihelj@irb.hr [Ruđer Bošković Institute, Department of Physical Chemistry, Laboratory for Synthesis and Processes of Self-assembling of Organic Molecules, Bijenička c. 54, P.O. Box 180, HR-10002 Zagreb (Croatia); Popović, Jasminka [Division for Materials Physics, Ruđer Bošković Institute, POB 180, HR-10002 Zagreb (Croatia); Skoko, Željko [Department of Physics, Faculty of Science, University of Zagreb, Bijenička cesta 32, HR-10000 Zagreb (Croatia); Tomašić, Vlasta, E-mail: vlastom@irb.hr [Ruđer Bošković Institute, Department of Physical Chemistry, Laboratory for Synthesis and Processes of Self-assembling of Organic Molecules, Bijenička c. 54, P.O. Box 180, HR-10002 Zagreb (Croatia)

    2014-09-10

    Highlights: • Thermal behavior of quaternary ammonium n-dodecylsulfates is characterized. • Typical layered structure dominates in all examined compounds at room temperature. • The dimeric didodecylsulfate crystallizes in monoclinic space group P21/m. • Thermotropic phases formation characteristic for multi-tailed n-dodecylsulfates. • Multi-charged n-dodecylsulfates are soft crystals at higher temperatures. - Abstract: Five novel anhydrous catanionic dodecylsulfates containing multi-charged and multi-tailed quaternary ammonium centers were synthesized and examined with light microscopy, differential scanning calorimetry and X-ray powder diffraction. This study is an attempt to explain the relationship between chemical structure, molecular architecture, phase transition characteristics and thermodynamics and the nature of intermolecular interactions of the individual amphiphiles that ultimately lead to different mesomorphic product. All examined compounds are of typical layered structure at room temperature. The long spacing decreases linearly with the increase of either ionic head or n-dodecyl chain number. The thermal analysis of the examined multi-charged catanionics indicates thermotropic mesomorphism, whereas multi-tailed dodecylsulfates show only properties of soft crystals. Maltese crosses, oily streaks textures, stepped drops and fan-shaped textures affirmed the existence of various smectic mesophases at room and higher temperatures. Thermodynamically the most ordered compound is dimeric didodecylsulfate, and the most disordered is three-tailed dodecylsulfate. The addition of the new quaternary ammonium center or alkyl chain causes the increment of the lattice energy first, and it decreases by further changes in the structure. The temperatures of crystallization decrease by any mentioned addition.

  15. Spectroscopic markers of the TR quaternary transition in human hemoglobin.

    Science.gov (United States)

    Schirò, Giorgio; Cammarata, Marco; Levantino, Matteo; Cupane, Antonio

    2005-04-01

    In this work, we use a sol-gel protocol to trap and compare the R and T quaternary states of both the deoxygenated (deoxyHb) and carbonmonoxide (HbCO) derivatives of human hemoglobin. The near infrared optical absorption band III and the infrared CO stretching band are used to detect the effect of quaternary structure on the spectral properties of deoxyHb and HbCO; comparison with myoglobin allows for an assessment of tertiary and quaternary contributions to the measured band shifts. The RT transition is shown to cause a blue shift of the band III by approximately 35 cm(-1) for deoxyHb and a red shift of the CO stretching band by only approximately 0.3 cm(-1) for HbCO. This clearly shows that quaternary structure changes are transmitted to the heme pocket and that effects on deoxyHb are much larger than on HbCO, at least as far as the band energies are concerned. Experiments performed in the ample temperature interval of 300-10K show that the above quaternary structure effects are "static" and do not influence the dynamic properties of the heme pocket, at least as probed by the temperature dependence of band III and of the CO stretching band. The availability of quaternary structure sensitive spectroscopic markers and the quantitative measurement of the quaternary structure contribution to band shifts will be of considerable help in the analysis of flash-photolysis experiments on hemoglobin. Moreover, it will enable one to characterize the dynamic properties of functionally relevant hemoglobin intermediates and to study the kinetics of both the T-->R and R-->T quaternary transitions through time-resolved spectroscopy.

  16. Quaternary sediments in Rybalsryi quarry of Dnipropetrovsk

    Directory of Open Access Journals (Sweden)

    Manyuk V.V.

    2014-12-01

    Full Text Available The results of a study of the typical section of Quaternary sediments in the Rybalske quarry and first time been reported to shift to the South boundary of the spread of the Dneprovian ice cover. Long-term observation of the geological structure subaerial and subaqueous deposits in Quaternary escarpment quarry clearly demonstrates the exceptional value, integrity, and at the same time, a certain exclusivity individual elements Quaternary section. Middle-upper Pleistocene section of substantially exceeds disclosed in Sazhovka draw, where the stratotype Kodatskiy fossil soil and elevated section of Quaternary sediments. If old Kodak can see only fragments section, an opened side by deep ravines and conditions of use cleared, the Rybalske quarry ledge submitted in one complete section alternation fossil soil horizons and loess - loess from the Dnieper to the modern black soil, and another ledge next to, well the rest of the section is exposed (from Tilihulske to Shyrokynske klimatolite. Established that among the many famous sections subaerial deposits located in the Middle Dnieper in the north-eastern part of the Dnieper-Donets basin, in the Black Sea and the Crimea and studied by the author in different years, and described loess and soil horizons (from the Black Sea to the Dnieper differ markedly lack of connectivity, flowability and friability. It is logical to assume that lithofacies conditions of the thicker subaerial deposits in the wellhead part Samara, where the Rybalske quarry markedly different from existing in these areas. Despite the obvious influence of the Dnieper glacier, direct signs which surround Dnipropetrovs’k north must be other reasons not yet explored. It is worth noting another important feature of the section of Quaternary sediments in fishing career. The above section is characteristic of the north-eastern part of the quarry, while the north, at higher marks of the watershed in the lower parts of thicker Quaternary

  17. Newly synthesized MgAl2Ge2: A first-principles comparison with its silicide and carbide counterparts

    Science.gov (United States)

    Tanveer Karim, A. M. M.; Hadi, M. A.; Alam, M. A.; Parvin, F.; Naqib, S. H.; Islam, A. K. M. A.

    2018-06-01

    Using plane-wave pseudopotential density functional theory (DFT), the first-principle calculations are performed to investigate the structural aspects, mechanical behaviors and electronic features of the newly synthesized CaAl2Si2-prototype intermetallic compound, MgAl2Ge2 for the first time and the results are compared with those calculated for its silicide and carbide counterparts MgAl2Si2 and MgAl2C2. The calculated lattice constants agree fairly well with their corresponding experimental values. The estimated elastic tensors satisfy the mechanical stability conditions for MgAl2Ge2 along with MgAl2Si2 and MgAl2C2. The level of elastic anisotropy increases following the sequence of X-elements Ge → Si → C. MgAl2Ge2 and MgAl2Si2 are expected to be ductile and damage tolerant, while MgAl2C2 is a brittle one. MgAl2Ge2 and MgAl2Si2 should exhibit better thermal shock resistance and low thermal conductivity and accordingly these can be used as thermal barrier coating (TBC) materials. The Debye temperature of MgAl2Ge2 is lowest among three intermetallic compounds. MgAl2Ge2 and MgAl2Si2 should exhibit metallic conductivity; while the dual characters of weak-metals and semiconductors are expected for MgAl2C2. The values of theoretical Vickers hardness for MgAl2Ge2, MgAl2Si2, and MgAl2C2 are 3.3, 2.7, and 7.7 GPa, respectively, indicating that these three intermetallics are soft and easily machinable.

  18. Antibacterial effect of composite resins containing quaternary ammonium polyethyleneimine nanoparticles

    International Nuclear Information System (INIS)

    Yudovin-Farber, Ira; Beyth, Nurit; Weiss, Ervin I.; Domb, Abraham J.

    2010-01-01

    Quaternary ammonium polyethyleneimine (QA-PEI)-based nanoparticles were synthesized by crosslinking with dibromopentane followed by N-alkylation with various alkyl halides and further N-methylation with methyl iodide. Insoluble pyridinium-type particles were prepared by suspension polymerization of 4-vinyl pyridine followed by N-alkylation with alkyl halides. Polyamine-based nanoparticles embedded in restorative composite resin at 1% w/w were tested for antibacterial activity against Streptococcus mutans using direct contact test. Activity analysis revealed that the alkyl chain length of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl-alkylated QA-PEI embedded in restorative composite resin at 1% w/w that totally inhibited S. mutans growth in 3-month-aged samples. This data indicates that restorative composite resin with antibacterial properties can be produced by the incorporation of QA-PEI nanoparticles.

  19. Antibacterial effect of composite resins containing quaternary ammonium polyethyleneimine nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Yudovin-Farber, Ira [Hebrew University of Jerusalem, Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Faculty of Medicine (Israel); Beyth, Nurit; Weiss, Ervin I. [Hebrew University of Jerusalem, Department of Prosthodontics, Faculty of Dentistry (Israel); Domb, Abraham J., E-mail: avid@ekmd.huji.ac.i [Hebrew University of Jerusalem, Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Faculty of Medicine (Israel)

    2010-02-15

    Quaternary ammonium polyethyleneimine (QA-PEI)-based nanoparticles were synthesized by crosslinking with dibromopentane followed by N-alkylation with various alkyl halides and further N-methylation with methyl iodide. Insoluble pyridinium-type particles were prepared by suspension polymerization of 4-vinyl pyridine followed by N-alkylation with alkyl halides. Polyamine-based nanoparticles embedded in restorative composite resin at 1% w/w were tested for antibacterial activity against Streptococcus mutans using direct contact test. Activity analysis revealed that the alkyl chain length of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl-alkylated QA-PEI embedded in restorative composite resin at 1% w/w that totally inhibited S. mutans growth in 3-month-aged samples. This data indicates that restorative composite resin with antibacterial properties can be produced by the incorporation of QA-PEI nanoparticles.

  20. Quaternary ammonium-functionalized silica sorbents for the solid-phase extraction of aromatic amines under normal phase conditions.

    Science.gov (United States)

    Vidal, Lorena; Robin, Orlane; Parshintsev, Jevgeni; Mikkola, Jyri-Pekka; Riekkola, Marja-Liisa

    2013-04-12

    Quaternary ammonium-functionalized silica materials were synthesized and applied for solid-phase extraction (SPE) of aromatic amines, which are classified as priority pollutants by US Environmental Protection Agency. Hexamethylenetetramine used for silica surface modification for the first time was employed as SPE sorbent under normal phase conditions. Hexaminium-functionalized silica demonstrated excellent extraction efficiencies for o-toluidine, 4-ethylaniline and quinoline (recoveries 101-107%), while for N,N-dimethylaniline and N-isopropylaniline recoveries were from low to moderate (14-46%). In addition, the suitability of 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica as SPE sorbent was tested under normal phase conditions. The recoveries achieved for the five aromatic amines ranged from 89 to 99%. The stability of the sorbent was evaluated during and after 150 extractions. Coefficients of variation between 4.5 and 10.2% proved a high stability of the synthesized sorbent. Elution was carried out using acetonitrile in the case of hexaminium-functionalized silica and water for 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent. After the extraction the analytes were separated and detected by liquid chromatography ultraviolet detection (LC-UV). The retention mechanism of the materials was primarily based on polar hydrogen bonding and π-π interactions. Comparison made with activated silica proved the quaternary ammonium-functionalized materials to offer different selectivity and better extraction efficiencies for aromatic amines. Finally, 1-alkyl-3-(propyl-3-sulfonate) imidazolium-functionalized silica sorbent was successfully tested for the extraction of wastewater and soil samples. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Thiolated quaternary ammonium-chitosan conjugates for enhanced precorneal retention, transcorneal permeation and intraocular absorption of dexamethasone.

    Science.gov (United States)

    Zambito, Ylenia; Di Colo, Giacomo

    2010-06-01

    Previously, a quaternary ammonium (N(+))-chitosan (Ch) conjugate (N(+)(60)-Ch) characterized by short pendant chains, made of 1.7+/-0.1 adjacent diethyl-dimethylene-ammonium groups, substituted onto the primary amino group of the chitosan repeating units (degree of substitution, 59.2+/-4.5%) was used to synthesize a multifunctional non-cytotoxic thiomer (N(+)(60)-Ch-SH(5)), carrying 4.5+/-0.7% thiol-bearing 3-mercaptopropionamide besides quaternary ammonium groups. The present work was aimed at evaluating the potential of N(+)(60)-Ch-SH(5) and N(+)(60)-Ch as bioactive excipients for dexamethasone (DMS) eyedrops. The DMS permeability across excised rabbit cornea was enhanced over the control value by the thiomer and the parent polymer to about the same extent (3.8 vs. 4.1 times). The mean precorneal retention time and AUC in the aqueous of DMS instilled in rabbit eyes via eyedrops were enhanced by the thiomer (MRT=77.96+/-3.57 min, AUC=33.19+/-6.96 microg ml(-1) min) more than the parent polymer (MRT=65.74+/-4.91 min, AUC=21.48+/-3.81 microg ml(-1) min) over the control (MRT=5.07+/-0.25 min, AUC=6.25+/-0.65 microg ml(-1) min). The quaternary ammonium ions were responsible for both permeabilization of corneal epithelium and polymer adhesion to precorneal mucus, while the thiols increased the latter. This synergistic action is the basis of the higher thiomer bioactivity in vivo. A good ocular tolerability of the chitosan derivatives resulted from in vivo experiments. Copyright 2010 Elsevier B.V. All rights reserved.

  2. Second Quaternary dating workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    The second Quaternary dating methods workshop was held at Lucas Heights and sponsored by ANSTO and AINSE. Topics covered include, isotope and thermoluminescence dating, usage of accelerator and thermal ionisation mass spectrometry in environmental studies emphasizing on the methodologies used and sample preparation

  3. Second Quaternary dating workshop

    International Nuclear Information System (INIS)

    1999-01-01

    The second Quaternary dating methods workshop was held at Lucas Heights and sponsored by ANSTO and AINSE. Topics covered include, isotope and thermoluminescence dating, usage of accelerator and thermal ionisation mass spectrometry in environmental studies emphasizing on the methodologies used and sample preparation

  4. Increased therapeutic efficacy of a newly synthesized tyrosinase inhibitor by solid lipid nanoparticles in the topical treatment of hyperpigmentation

    Directory of Open Access Journals (Sweden)

    Al-Amin M

    2016-12-01

    Full Text Available Md Al-Amin, Jiafu Cao, Muhammad Naeem, Hasanul Banna, Min-Soo Kim, Yunjin Jung, Hae Young Chung, Hyung Ryong Moon, Jin-Wook Yoo College of Pharmacy, Pusan National University, Busan, South Korea Abstract: Hyperpigmentation caused by melanin overproduction is a major skin disorder in humans. Inhibition of tyrosinase, a key regulator of melanin production, has been used as an effective strategy to treat hyperpigmentation. In this study, we investigated the use of solid lipid nanoparticles (SLNs as a highly effective and nontoxic means to deliver a newly synthesized potent tyrosinase inhibitor, MHY498, and to target melanocytes through the skin. MHY498-loaded SLNs (MHY-SLNs were prepared by an oil-in-water emulsion solvent-evaporation method, and their morphological and physicochemical properties were characterized. MHY-SLNs showed a prolonged drug-release profile and higher skin permeation than that of MHY solution. In an in vivo evaluation of antimelanogenic activity, MHY-SLNs showed a prominent inhibitory effect against ultraviolet B-induced melanogenesis, resulting in no change in the skin color of C57BL/6 mouse, compared with that observed in an MHY solution-treated group and an untreated control group. The antimelanogenic effect of MHY-SLNs was further confirmed through Fontana–Masson staining. Importantly, MHY-SLNs did not induce any toxic effects in the L929 cell line. Overall, these data indicate that MHY-SLNs show promise in the topical treatment of hyperpigmentation. Keywords: melanogenesis, hyperpigmentation, MHY498, solid lipid nanoparticles, skin delivery

  5. Quaternary oxide halides of group 15 with zinc and cadmium

    International Nuclear Information System (INIS)

    Rueck, Nadia

    2014-01-01

    The present thesis ''Quaternary oxide halides of group 15 with zinc and cadmium'' deals with the chemical class of oxide halides, which contain d-block element cations and pnicogens. Over the past few years compounds containing pnicogene cations are intensively investigated. The reason for this is the free electron pair of the Pn"3"+ cation, which is responsible for some interesting properties. Free electron pairs do not only impact the spatial structure of molecules but also the properties of materials. The object of this work was the synthesis and characterization of compounds containing Pn"3"+ cations with free electron pairs. Due to the structure-determining effect of these free electron pairs and in combination with halides it is possible to synthesize compounds with low-dimensional structures like chains and layers. In these compounds the structure is separated into halophilic and chalcophilic sub-structures, which are held together only by weak Van der Waals forces.

  6. Absolute age determination of quaternary fault and formation

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Chang Sik; Lee, Kwang Sik; Choi, Man Sik [Korea Basic Science Institute, Seoul (Korea, Republic of)] (and others)

    2002-04-15

    The annual ('01-'01) objective of this project is to data the fault activity for the presumed quaternary fault zones to the western part of the Ulsam fault system and southeastern coastal area near the Wolseong Nuclear Power Plant. Rb-Sr, K-Ar, OSL, C-14 and U-series disequilibrium methods were applied to the fault rocks, organic matter and quaternary formations collected from the Pyeonghae, Bogyeongsa, Yugyeri, Byegkye, Gacheon-1 and Joil outcrops of the Yangsan fault system, the Baenaegol outcrop of the Moryang fault system, the Susyongji(Madong-2), Singye, Hwalseongri, Ipsil and Wonwonsa outcrops of the Ulsan fault system and from quaternary marine terraces (Oryoo and Kwangseong sites) in the southeastern coastal area. The experimental procedure of the OSL SAR protocol was reexamined to get more reliable dating results.

  7. First-principles study of half-metallic properties in RbCaNZ (Z = O, S, and Se) quaternary Heusler compounds

    Science.gov (United States)

    Rezaei, S.; Ahmadian, F.

    2018-06-01

    On the basis of first principles calculations, the electronic structures and magnetic properties of quaternary Heusler alloys RbCaNZ (Z = O, S, and Se) were studied. The negative formation energies indicated that all these compounds were thermodynamically stable and thus may be experimentally synthesized at appropriate conditions in the future. The results showed that YI structure was the most favorable configuration among the three possible structures. All compounds were found to be half-metallic ferromagnets. The characteristic of energy bands and origin of half-metallicity were also verified. The total magnetic moments of RbCaNZ (Z = O, S, and Se) compounds were obtained 2μB per formula unit, which were in an agreement with Slater-Pauling rule (Mtot = 12 - Ztot). Half-metallicity was preserved at ranges of 5.06-8.36 Å, 5.96-8.81 Å, and 6.13-8.73 Å for RbCaNO, RbCaNS, and RbCaNSe compounds, respectively, which show that these quaternary Heusler compounds may be potential candidates in spintronic applications.

  8. Sequential character of low-energy ternary and quaternary nuclear fission

    Energy Technology Data Exchange (ETDEWEB)

    Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru; Bulychev, A. O. [Voronezh State University (Russian Federation)

    2016-09-15

    An analysis of low-energy true ternary (quaternary) nuclear fission leads to the conclusion that these fission modes have a sequential two-step (three-step) character such that the emission of a third particle (third and fourth particles) and the separation of fission fragments occur at distinctly different instants, in contrast to the simultaneous emergence of all fission products in the case of onestep ternary (quaternary) fission. This conclusion relies on the following arguments. First, the emission of a third particle (third and fourth particles) from a fissile nucleus is due to a nonevaporative mechanism associated with a nonadiabatic character of the collective deformation motion of this nucleus at the stages preceding its scission. Second, the axial symmetry of the deformed fissile compound nucleus and the direction of its symmetry axis both remain unchanged at all stages of ternary (quaternary) fission. This circumstancemakes it possible to explain themechanism of the appearance of observed anisotropies and T — odd asymmeries in the angular distributions of products of ternary (quaternary) nuclear fission. Third, the T —odd asymmetry discovered experimentally in ternary nuclear fission induced by cold polarized neutrons obeys the T —invariance condition only in the case of a sequential two-step (three-step) character of true ternary (quaternary) nuclear fission. At the same time, this asymmetry is not a T —invariant quantity in the case of the simultaneous emission of products of true ternary (quaternary) nuclear fission from the fissile compound nucleus.

  9. Sequential character of low-energy ternary and quaternary nuclear fission

    International Nuclear Information System (INIS)

    Kadmensky, S. G.; Bulychev, A. O.

    2016-01-01

    An analysis of low-energy true ternary (quaternary) nuclear fission leads to the conclusion that these fission modes have a sequential two-step (three-step) character such that the emission of a third particle (third and fourth particles) and the separation of fission fragments occur at distinctly different instants, in contrast to the simultaneous emergence of all fission products in the case of onestep ternary (quaternary) fission. This conclusion relies on the following arguments. First, the emission of a third particle (third and fourth particles) from a fissile nucleus is due to a nonevaporative mechanism associated with a nonadiabatic character of the collective deformation motion of this nucleus at the stages preceding its scission. Second, the axial symmetry of the deformed fissile compound nucleus and the direction of its symmetry axis both remain unchanged at all stages of ternary (quaternary) fission. This circumstancemakes it possible to explain themechanism of the appearance of observed anisotropies and T — odd asymmeries in the angular distributions of products of ternary (quaternary) nuclear fission. Third, the T —odd asymmetry discovered experimentally in ternary nuclear fission induced by cold polarized neutrons obeys the T —invariance condition only in the case of a sequential two-step (three-step) character of true ternary (quaternary) nuclear fission. At the same time, this asymmetry is not a T —invariant quantity in the case of the simultaneous emission of products of true ternary (quaternary) nuclear fission from the fissile compound nucleus.

  10. Diatom records in the Quaternary marine sequences around the Japanese Islands

    OpenAIRE

    Koizumi, Itaru; Yamamoto, Hirofumi

    2016-01-01

    Understanding the Quaternary is a key to estimating what the Earth's climate will be like in the future. Such studies demand high-resolution analyses based on paleoclimatic proxy records of changing Earth's orbital forcing and solar insolation that affect the climate system. Quaternary diatom biostratigraphy and paleoceanography have been well established based on the Quaternary marine sequences obtained by piston coring and deep-sea drilling around the Japanese Islands. This paper firstly re...

  11. Molecular Docking and Anticonvulsant Activity of Newly Synthesized Quinazoline Derivatives

    Directory of Open Access Journals (Sweden)

    Hatem A. Abuelizz

    2017-06-01

    Full Text Available A new series of quinazoline-4(3H-ones are evaluated for anticonvulsant activity. After intraperitoneal (ip injection to albino mice at a dose of 100 mg/kg body weight, synthesized quinazolin-4(3H-ones (1–24 were examined in the maximal electroshock (MES induced seizures and subcutaneous pentylenetetrazole (scPTZ induced seizure models in mice. The Rotarod method was applied to determine the neurotoxicity. Most of the compounds displayed anticonvulsant activity in the scPTZ screen at a dose range of 0.204–0.376 mmol/mL. Out of twenty-four, compounds 8, 13 and 19 proved to be the most active with a remarkable protection (100% against PTZ induced convulsions and four times more potent activity than ethosuximide. The structure-activity relationship concluded valuable pharmacophoric information, which was confirmed by the molecular docking studies using the target enzyme human carbon anhydrase II (HCA II. The studied quinazoline analogues suggested that the butyl substitution at position 3 has a significant effect on preventing the spread of seizure discharge and on raising the seizure threshold. However, benzyl substitution at position 3 has shown a strong anticonvulsant activity but with less seizure prevention compared to the butyl substitution.

  12. Cationic nanoparticles with quaternary ammonium-functionalized PLGA–PEG-based copolymers for potent gene transfection

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yan-Hsung [Kaohsiung Medical University, School of Dentistry, College of Dental Medicine (China); Fu, Yin-Chih [Kaohsiung Medical University, Graduate Institute of Medicine, College of Medicine (China); Chiu, Hui-Chi [Kaohsiung Medical University, Department of Medicinal and Applied Chemistry, College of Life Science (China); Wang, Chau-Zen [Kaohsiung Medical University, Department of Physiology, College of Medicine (China); Lo, Shao-Ping [Kaohsiung Medical University, Department of Medicinal and Applied Chemistry, College of Life Science (China); Ho, Mei-Ling [Kaohsiung Medical University, Department of Physiology, College of Medicine (China); Liu, Po-Len [Kaohsiung Medical University, Department of Respiratory Therapy, College of Medicine (China); Wang, Chih-Kuang, E-mail: ckwang@kmu.edu.tw [Kaohsiung Medical University, Department of Medicinal and Applied Chemistry, College of Life Science (China)

    2013-11-15

    The objective of the present work was to develop new cationic nanoparticles (cNPs) with amphiphilic cationic copolymers for the delivery of plasmid DNA (pDNA). Cationic copolymers were built on the synthesis of quaternary ammonium salt compounds from diethylenetriamine (DETA) to include the positively charged head group and amphiphilic multi-grafts. PLGA-phe-PEG-qDETA (PPD), phe-PEG-qDETA-PLGA (PDP), and PLGA-phe-PEG-qDETA-PLGA (PPDP) cationic copolymers were created by this moiety of DETA quaternary ammonium, heterobifunctional polyethylene glycol (COOH-PEG-NH{sub 2}), phenylalanine (phe), and poly(lactic-co-glycolic acid) (PLGA). These new cNPs were prepared by the water miscible solvent displacement method. They exhibit good pDNA binding ability, as shown in a retardation assay that occurred at a particle size of ∼217 nm. The zeta potential was approximately +21 mV when the cNP concentration was 25 mg/ml. The new cNPs also have a better buffering capacity than PLGA NPs. However, the pDNA binding ability was demonstrated starting at a weight ratio of approximately 6.25 cNPs/pDNA. Gene transfection results showed that these cNPs had transfection effects similar to those of Lipofectamine 2000 in 293T cells. Furthermore, cNPs can also transfect human adipose-derived stem cells. The results indicate that the newly developed cNP is a promising candidate for a novel gene delivery vehicle.

  13. Nanocrystals of the quaternary thermoelectric materials: AgPb{sub m}SbTe{sub m+2}(m=1-18): Phase-segregated or solid solutions?

    Energy Technology Data Exchange (ETDEWEB)

    Arachchige, Indika U [Department of Chemistry, Northwestern University Evanston, IL (United States); Wu, Jinsong; Dravid, Vinayak P [Department of Materials Science and Engineering, Northwestern University Evanston, IL (United States); Kanatzidis, Mercouri G [Department of Chemistry, Northwestern University Evanston, IL (United States); Material Science Division, Argonne National Laboratory Argonne, IL (United States)

    2008-10-02

    Facile synthesis of a series of thermoelectrically relevant AgPb{sub m}SbTe{sub m+2}(m=1-18) nanoparticles is carried out by using a colloidal synthetic route. As-synthesized nanocrystals are spherical in geometry and adopt a cubic NaCl-type structure. These quaternary nanocrystals behave as solid solutions at room temperature and tend to phase separate into AgSbTe{sub 2} and PbTe upon annealing at moderately high temperature. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  14. Is Quaternary geology ready for the future?

    Science.gov (United States)

    Ritter, Dale F.

    1996-07-01

    Armed with a better understanding of process and an array of developing dating techniques, Quaternary geology is poised to achieve greater recognition in the general scientific community. This recognition however, will require some thought adjustment. Quaternary geologists will have to convince government, industry and a variety of scientific groups that they possess unique training and expertise that is needed as part of the thrust to fully understand and/or resolve major scientific problems. Therefore, future research and education efforts should not focus on developing a rigidly defined identity within geoscience, but instead should seek ways to be integrated with interdisciplinary teams that will investigate complex environmental and climate change problems. Such a scenaria creates and enermous dilemma for Quaternary geologists because they will derive greater intellectual stimulation from scientists working in discplines other than geology, and their scientific collaboratiors will most likely not be their academic colleagues. This outward expansion of our scientific network will require the development of interdsciplinary research collaboration and/or degree-granting programs at the graduate level. To accomplish such goals, universities must resist "turf protection", and funding agencies muts become more efficient at facilitating interdisciplinary research.

  15. DNA Barcoding through Quaternary LDPC Codes.

    Science.gov (United States)

    Tapia, Elizabeth; Spetale, Flavio; Krsticevic, Flavia; Angelone, Laura; Bulacio, Pilar

    2015-01-01

    For many parallel applications of Next-Generation Sequencing (NGS) technologies short barcodes able to accurately multiplex a large number of samples are demanded. To address these competitive requirements, the use of error-correcting codes is advised. Current barcoding systems are mostly built from short random error-correcting codes, a feature that strongly limits their multiplexing accuracy and experimental scalability. To overcome these problems on sequencing systems impaired by mismatch errors, the alternative use of binary BCH and pseudo-quaternary Hamming codes has been proposed. However, these codes either fail to provide a fine-scale with regard to size of barcodes (BCH) or have intrinsic poor error correcting abilities (Hamming). Here, the design of barcodes from shortened binary BCH codes and quaternary Low Density Parity Check (LDPC) codes is introduced. Simulation results show that although accurate barcoding systems of high multiplexing capacity can be obtained with any of these codes, using quaternary LDPC codes may be particularly advantageous due to the lower rates of read losses and undetected sample misidentification errors. Even at mismatch error rates of 10(-2) per base, 24-nt LDPC barcodes can be used to multiplex roughly 2000 samples with a sample misidentification error rate in the order of 10(-9) at the expense of a rate of read losses just in the order of 10(-6).

  16. DNA Barcoding through Quaternary LDPC Codes.

    Directory of Open Access Journals (Sweden)

    Elizabeth Tapia

    Full Text Available For many parallel applications of Next-Generation Sequencing (NGS technologies short barcodes able to accurately multiplex a large number of samples are demanded. To address these competitive requirements, the use of error-correcting codes is advised. Current barcoding systems are mostly built from short random error-correcting codes, a feature that strongly limits their multiplexing accuracy and experimental scalability. To overcome these problems on sequencing systems impaired by mismatch errors, the alternative use of binary BCH and pseudo-quaternary Hamming codes has been proposed. However, these codes either fail to provide a fine-scale with regard to size of barcodes (BCH or have intrinsic poor error correcting abilities (Hamming. Here, the design of barcodes from shortened binary BCH codes and quaternary Low Density Parity Check (LDPC codes is introduced. Simulation results show that although accurate barcoding systems of high multiplexing capacity can be obtained with any of these codes, using quaternary LDPC codes may be particularly advantageous due to the lower rates of read losses and undetected sample misidentification errors. Even at mismatch error rates of 10(-2 per base, 24-nt LDPC barcodes can be used to multiplex roughly 2000 samples with a sample misidentification error rate in the order of 10(-9 at the expense of a rate of read losses just in the order of 10(-6.

  17. Photoluminescent nano-sized ternary and quaternary complexes of thorium(IV)

    International Nuclear Information System (INIS)

    Baranwal, B.P.; Jain, A.K.; Varma, A.; Singh, A.K.; Fatma, T.

    2011-01-01

    Some ternary and quaternary complexes of thorium(IV) with the general formula [Th(OOCCH 3 ) 2-n (SB) n (OOCC 15 H 31 ) 2 ] (HSB=Schiff bases and n=1 or 2) have been synthesized by the stepwise substitutions of acetate ions from thorium(IV) acetate, first with straight chain carboxylic acid and then with Schiff bases. The complexes are characterized by elemental analyses, spectral (electronic, infrared, 1 H NMR, FAB mass, photoluminescence and powder XRD) and TEM studies. Conductance measurements indicated non-conducting behaviour of the complexes. Structural parameters from powder XRD data for complexes 5 and 6 which indicate poorly crystalline nano-sized triclinic particles. Electronic absorption spectra of the complexes showed π → π * and n → π * charge transfer transitions. All complexes displayed fluorescence and a correlation was sought between luminescence spectra of complexes in solution at room temperature. On the basis of physico-chemical studies, coordination number 8 was assigned for thorium(IV) in the complexes. The morphology and microstructure of the complexes were examined with transmission electron microscopy (TEM) and the selected area electron diffraction (SAED). (orig.)

  18. Atomic-scale properties of Ni-based FCC ternary, and quaternary alloys

    International Nuclear Information System (INIS)

    Tamm, Artur; Aabloo, Alvo; Klintenberg, Mattias; Stocks, Malcolm; Caro, Alfredo

    2015-01-01

    The aim of this study is to characterize some atomic-scale properties of Ni-based FCC multicomponent alloys. For this purpose, we use Monte Carlo method combined with density functional theory calculations to study short-range order (SRO), atomic displacements, electronic density of states, and magnetic moments in equimolar ternary NiCrCo, and quaternary NiCrCoFe alloys. According to our study, the salient features for the ternary alloy are a negative SRO parameter between Ni–Cr and a positive between Cr–Cr pairs as well as a weakly magnetic state. For the quaternary alloy we predict negative SRO parameter for Ni–Cr and Ni–Fe pairs and positive for Cr–Cr and Fe–Fe pairs. Atomic displacements for both ternary and quaternary alloys are negligible. In contrast to the ternary, the quaternary alloy shows a complex magnetic structure. The electronic structure of the ternary and quaternary alloys shows differences near the Fermi energy between a random solid solution and the predicted structure with SRO. Despite that, the calculated EXAFS spectra does not show enough contrast to discriminate between random and ordered structures. The predicted SRO has an impact on point-defect energetics, electron–phonon coupling and thermodynamic functions and thus, SRO should not be neglected when studying properties of these two alloys

  19. Radio-labelled quaternary compounds and their diagnostic use

    International Nuclear Information System (INIS)

    Woo, D.V.

    1984-01-01

    Radio-labelled compounds having a lipophilic cation, which are quaternary ammonium, phosphonium or arsonium halides, in which the halide is a chloride, bromide or iodide, and in which the four quaternary substituents are independently selected from Csub(1-3) alkyl, phenyl and benzyl, at least two substituents being phenyl or benzyl, and one phenyl or benzyl substituent carrying a ring-substituent selected from 123 I, 125 I, 131 I, 77 Br, 82 Br and 18 F. Such compounds can be administered by injection, and a radio-image of the myocardium obtained. (author)

  20. Mitochondrial nucleoid clusters protect newly synthesized mtDNA during Doxorubicin- and Ethidium Bromide-induced mitochondrial stress

    Energy Technology Data Exchange (ETDEWEB)

    Alán, Lukáš, E-mail: lukas.alan@fgu.cas.cz; Špaček, Tomáš; Pajuelo Reguera, David; Jabůrek, Martin; Ježek, Petr

    2016-07-01

    Mitochondrial DNA (mtDNA) is compacted in ribonucleoprotein complexes called nucleoids, which can divide or move within the mitochondrial network. Mitochondrial nucleoids are able to aggregate into clusters upon reaction with intercalators such as the mtDNA depletion agent Ethidium Bromide (EB) or anticancer drug Doxorobicin (DXR). However, the exact mechanism of nucleoid clusters formation remains unknown. Resolving these processes may help to elucidate the mechanisms of DXR-induced cardiotoxicity. Therefore, we addressed the role of two key nucleoid proteins; mitochondrial transcription factor A (TFAM) and mitochondrial single-stranded binding protein (mtSSB); in the formation of mitochondrial nucleoid clusters during the action of intercalators. We found that both intercalators cause numerous aberrations due to perturbing their native status. By blocking mtDNA replication, both agents also prevented mtDNA association with TFAM, consequently causing nucleoid aggregation into large nucleoid clusters enriched with TFAM, co-existing with the normal nucleoid population. In the later stages of intercalation (> 48 h), TFAM levels were reduced to 25%. In contrast, mtSSB was released from mtDNA and freely distributed within the mitochondrial network. Nucleoid clusters mostly contained nucleoids with newly replicated mtDNA, however the nucleoid population which was not in replication mode remained outside the clusters. Moreover, the nucleoid clusters were enriched with p53, an anti-oncogenic gatekeeper. We suggest that mitochondrial nucleoid clustering is a mechanism for protecting nucleoids with newly replicated DNA against intercalators mediating genotoxic stress. These results provide new insight into the common mitochondrial response to mtDNA stress and can be implied also on DXR-induced mitochondrial cytotoxicity. - Highlights: • The mechanism for mitochondrial nucleoid clustering is proposed. • DNA intercalators (Doxorubicin or Ethidium Bromide) prevent TFAM

  1. Minimal erosion of Arctic alpine topography during late Quaternary glaciation

    Science.gov (United States)

    Gjermundsen, Endre F.; Briner, Jason P.; Akçar, Naki; Foros, Jørn; Kubik, Peter W.; Salvigsen, Otto; Hormes, Anne

    2015-10-01

    The alpine topography observed in many mountainous regions is thought to have formed during repeated glaciations of the Quaternary period. Before this time, landscapes had much less relief. However, the spatial patterns and rates of Quaternary exhumation at high latitudes--where cold-based glaciers may protect rather than erode landscapes--are not fully quantified. Here we determine the exposure and burial histories of rock samples from eight summits of steep alpine peaks in northwestern Svalbard (79.5° N) using analyses of 10Be and 26Al concentrations. We find that the summits have been preserved for at least the past one million years. The antiquity of Svalbard’s alpine landscape is supported by the preservation of sediments older than one million years along a fjord valley, which suggests that both mountain summits and low-elevation landscapes experienced very low erosion rates over the past million years. Our findings support the establishment of northwestern Svalbard’s alpine topography during the early Quaternary. We suggest that, as the Quaternary ice age progressed, glacial erosion in the Arctic became inefficient and confined to ice streams, and high-relief alpine landscapes were preserved by minimally erosive glacier armour.

  2. The ichthyofauna of limnic systems in Quaternary deposits of extreme southern Brazil

    Directory of Open Access Journals (Sweden)

    Cindy Marques

    2016-12-01

    Full Text Available The Quaternary in the state of Rio Grande do Sul (RS, southern Brazil, is geologically represented by the coastal plain and was originated by successive events of Pleistocene-Holocene marine transgressions and the occurrence of alluvial deposits. This paper aimed to characterize the fish assemblage occurring in a swampy Quaternary area adjacent to Lagoa Pequena, a lacustrine system connected to the west margin of the Laguna dos Patos estuary. A checklist is also provided of the ichthyofauna so far recorded in limnic systems of Quaternary deposits in the state of Rio Grande do Sul. A total of 42 species was recorded, distributed in nine orders, 18 families and 31 genera. Characidae and Cichlidae were the most representative families, comprising 15 and 4 species respectively. A bibliographic revision associated to our sample data revealed the occurrence of 156 species in limnic systems inserted in RS Quaternary deposits (114 limnic, 15 marine/estuarine/limnic, ten marine/estuarine, nine estuarine/limnic and eight marine. Characiformes and Siluriformes are the most diverse orders, corroborating the Neotropical pattern. Seven species can be considered endemic to RS Quaternary deposits.

  3. The fate and role of macromolecules synthesized during mammalian oocyte meiotic maturation. I. Autoradiographic topography of newly synthesized RNA and protein in the germinal vesicle of the pig and rabbit

    International Nuclear Information System (INIS)

    Motlik, J.; Kopecny, V.; Pivko, J.

    1978-01-01

    Pig and rabbit oocytes were cytoautoradiographically checked for their synthetic activities during meiotic maturation. Tritiated uridine and lysine or 35 S-methionine were introduced into the culture medium in which the oocytes were maintained either immediately at the beginning of the germinal vesicle breakdown in vitro or after reaching a more advanced stage of this process in vitro or in vivo. Some oocytes were maintained thereafter in a cold medium to trace the metabolism of the labelled protein. In addition to uridine- 3 H incorporation into the nucleolus and nucleoplasm, during pig oocyte maturation it was found that an intensive RNA synthesis site appeared in association with condensing chromocentres of the GV II. A considerable proportion of oocytes from slaughterhouse material did not show intensive GV activity in RNA synthesis during maturation in vitro. In the pig and rabbit oocyte it was shown that the newly synthesized 3 H-lysine-labelled protein accumulated to a high degree in the GV and in the nucleolus. The labelled protein accumulated in the GV up to the stage of GV IV (pig) and persisted during the chase period in the ooplasm; it was found to be associated with chromosomes of metaphase I (pig) or metaphase II (rabbit) of the meiotic division. The process of protein accumulation in the GV was not influenced by meiotic arrest during oocyte culture in autologous follicular fluid. A similar accumulation of the label in the GV was detected in oocytes which were cultured in a medium enriched by 35 S-methionine. In some oocytes the labelled protein failed to accumulate in the nucleolar area during maturation in vitro

  4. Electrochemical oxidation of quaternary ammonium electrolytes : Unexpected side reactions in organic electrochemistry

    NARCIS (Netherlands)

    Nouri Nigjeh, Eslam; de Vries, Marcel; Bruins, Andries P.; Bischoff, Rainer; Permentier, Hjalmar P.

    Quaternary ammonium salts are among the most widely used electrolytes in organic electrochemistry, but there is little known about their unwanted side oxidation reactions. We have, therefore, studied the constant potential oxidation products of quaternary ammonium electrolytes using mass

  5. Quaternary naltrexone reverses radiogenic and morphine-induced locomotor hyperactivity

    Energy Technology Data Exchange (ETDEWEB)

    Mickley, G.A.; Stevens, K.E.; Galbraith, J.A.; White, G.A.; Gibbs, G.L.

    1984-04-01

    The present study attempted to determine the relative role of the peripheral and central nervous system in the production of morphine-induced or radiation-induced locomotor hyperactivity of the mouse. Toward this end, we used a quaternary derivative of an opiate antagonist (naltrexone methobromide), which presumably does not cross the blood-brain barrier. Quaternary naltrexone was used to challenge the stereotypic locomotor response observed in these mice after either an i.p. injection of morphine or exposure to 1500 rads /sup 60/Co. The quaternary derivative of naltrexone reversed the locomotor hyperactivity normally observed in the C57BL/6J mouse after an injection of morphine. It also significantly attenuated radiation-induced locomotion. The data reported here support the hypothesis of endorphin involvement in radiation-induced and radiogenic behaviors. However, these conclusions are contingent upon further research which more fully evaluates naltrexone methobromide's capacity to cross the blood-brain barrier.

  6. Quaternary Pt{sub 2}Ru{sub 1}Fe{sub 1}M{sub 1}/C (M=Ni, Mo, or W) catalysts for methanol electro-oxidation reaction

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Min Ku; Lee, Ki Rak; Kang, Kweon Ho; Park, Geun Il [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Jeon, Hyung Joon [Kyoto University, Kyoto (Japan); McGinn, Paul J. [University of Notre Dame, Indiana (United States)

    2015-02-15

    Quaternary Pt{sub 2}Ru{sub 1}Fe{sub 1}M{sub 1}/C (M=Ni, Mo, or W) catalysts were investigated for the methanol electro-oxidation reaction (MOR). Electrocatalytic activities of the quaternary catalysts for CO electro-oxidation were studied via CO stripping experiments, and the Pt{sub 2}Ru{sub 1}Fe{sub 1}Ni{sub 1}/C and Pt{sub 2}Ru{sub 1}Fe{sub 1}W{sub 1}/C catalysts exhibited lowered on-set potential compared to that of a commercial PtRu/C catalyst. MOR activities of the quaternary catalysts were determined by linear sweep voltammetry (LSV) experiments, and the Pt{sub 2}Ru{sub 1}Fe{sub 1}W{sub 1}/C catalyst outperformed the commercial PtRu/C catalyst by 170 and 150% for the mass and specific activities, respectively. X-ray photoelectron spectroscopy (XPS) was employed to analyze surface oxidation states of constituent atoms, and it was identified that the structure of the synthesized catalysts are close to a nano-composite of Pt and constituent metal hydroxides and oxides. In addition, the XPS results suggested that the bi-functional mechanism accounts for the improved performance of the Pt{sub 2}Ru{sub 1}Fe{sub 1}Ni{sub 1}/C and Pt{sub 2}Ru{sub 1} Fe{sub 1}W{sub 1}/C catalysts.

  7. The Plio-Quaternary Magdalena Turbidite System

    OpenAIRE

    Estrada, Ferran; Alonso, Belén; Ercilla, Gemma

    2011-01-01

    2006. Estrada F., Alonso B., Ercilla G. The Plio-Quaternary Magdalena Turbidite System. SEPM/Geological Society of London conference “External Controls on Deepwater Depositional Systems”, to be held at the Geological Society in Piccadilly, London, March 27th to 29th.

  8. KFeSbTe3: A quaternary chalcogenide aerogel for preferential adsorption of polarizable hydrocarbons and gases

    KAUST Repository

    Ahmed, Ejaz

    2015-01-01

    The first telluride-based quaternary aerogel KFeSbTe3 is synthesized by a sol-gel metathesis reaction between Fe(OAc)2 and K3SbTe3 in dimethyl formamide. The aerogel has an exceptionally large surface area 652 m2 g-1 which is amongst the highest reported for chalcogenide-based aerogels. This predominantly mesoporous material shows preferential adsorption for toluene vapors over cyclohexane or cyclopentane and CO2 over CH4 or H2. The remarkably high adsorption capacity for toluene (9.31 mmol g-1) and high selectivity for gases (CO2/H2: 121 and CO2/CH4: 75) suggest a potential use of such materials in adsorption-based separation processes for the effective purification of hydrocarbons and gases. © The Royal Society of Chemistry 2015.

  9. In vitro studies of immunoglobulin heavy-chain binding protein (BiP, GRP78). Interactions of BiP with newly synthesized proteins and adenine nucleotides

    International Nuclear Information System (INIS)

    Kassenbrock, C.K.

    1988-01-01

    Here we examine the interaction of BiP with newly synthesized polypeptides in an in vitro protein translations-translocation system. We find that BiP forms tight complexes with nonglycosylated yeast invertase and incorrectly disulfide-bonded prolactin but not with glycosylated invertase or correctly disulfide-bonded prolactin. Moreover, BiP associates detectably only with completed chains of prolactin, not with chains undergoing synthesis. We conclude that BiP recognizes and binds with high affinity to aberrantly folded or aberrantly glycosylated polypeptides in vitro, but not to all nascent chains as they are folding. BiP also binds APT and can be purified by APT affinity chromatography. We show that submicromolar levels of ATP or ADP decrease the rate of absorption of 125 I-BiP to nitrocellulose filters coated with protein or nonionic detergents. ATP and ADP also protect portions of BiP from proteolytic degradation. In contrast, micromolar levels of AMP increase the rate of adsorption and the rate of proteolytic degradation of BiP. We also show that an ATPase activity co-purifies with BiP, but its slow turnover number suggests a regulatory, rather than a functional role. The BiP-associated ATPase shares several properties with the related cytoplasmic protein, HSC70/clathrin uncoating ATPase

  10. LW-214, a newly synthesized flavonoid, induces intrinsic apoptosis pathway by down-regulating Trx-1 in MCF-7 human breast cells.

    Science.gov (United States)

    Pan, Di; Li, Wei; Miao, Hanchi; Yao, Jing; Li, Zhiyu; Wei, Libin; Zhao, Li; Guo, Qinglong

    2014-02-15

    In this study, the anticancer effect of LW-214, a newly synthesized flavonoid, against MCF-7 human breast cancer cells and the underlying mechanisms were investigated. LW-214 triggered the mitochondrial apoptotic pathway by increasing Bax/Bcl-2 ratio, loss of mitochondrial membrane potential (ΔΨm) and caspase-9 activation, degradation of poly (ADP-ribose) polymerase (PARP), cytochrome c (Cyt c) release and apoptosis-inducing factor (AIF) transposition. Further research revealed that both the reactive oxygen species (ROS) generation and the apoptosis signal regulating kinase 1 (ASK1) activation by LW-214 were induced by down-regulating the thioredoxin-1 (Trx-1) expression. The ROS elevation and ASK1 activation induced a sustained phosphorylation of c-Jun N-terminal kinase (JNK), while SP600125, as known as JNK inhibitor, almost reversed LW-214-induced apoptosis in MCF-7 cells. Overexpression of Trx-1 in MCF-7 cells attenuated LW-214-mediated apoptosis as well as the JNK activation and reversed the expression of mitochondrial apoptosis-related protein. Accordingly, the in vivo study showed that LW-214 exhibited a potential antitumor effect in BALB/c species mice inoculated MCF-7 tumor with low systemic toxicity, and the mechanism was the same as in vitro study. Taken together, these findings indicated that LW-214 may down-regulated Trx-1 function, causing intracellular ROS generation and releasing the ASK1, and lead to JNK activation, which consequently induced the mitochondrial apoptosis in vitro and in vivo. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. A Physicochemical and Pharmacological Study of the Newly Synthesized Complex of Albendazole and the Polysaccharide Arabinogalactan from Larch Wood.

    Science.gov (United States)

    Chistyachenko, Yulia S; Meteleva, Elizaveta S; Pakharukova, Maria Y; Katokhin, Aleksey V; Khvostov, Mikhail V; Varlamova, Anastasiya I; Glamazdin, Igor I; Khalikov, Salavat S; Polyakov, Nikolay E; Arkhipov, Ivan A; Tolstikova, Tatyana G; Mordvinov, Viatcheslav A; Dushkin, Alexander V; Lyakhov, Nikolay Z

    2015-01-01

    Inclusion complexes of albendazole (ABZ) with the polysaccharide arabinogalactan from larch wood Larix sibirica and Larix gmelinii were synthesized using a solid-state mechanochemical technology. We investigated physicochemical properties of the synthesized complexes in the solid state and in aqueous solutions as well as their anthelmintic activity against Trichinella spiralis, Hymenolepis nаna, Fasciola hepatica, Opisthorchis felineus, and mixed nematodoses of sheep. Formation of the complexes was demonstrated by means of intrinsic solubility and the NMR relaxation method. The mechanochemically synthesized complexes were more stable in comparison with the complex produced by mixing solutions of the components. The complexes of ABZ showed anthelmintic activity at 10-fold lower doses than did free ABZ. The complexes also showed lower acute toxicity and hepatotoxicity. These results suggest that it is possible to design new drugs on the basis of the ABZ:arabinogalactan complex that are safer and more effective than albendazole.

  12. Direct preparation of a graphene oxide modified monolith in a glass syringe as a solid-phase extraction cartridge for the extraction of quaternary ammonium alkaloids from Chinese patent medicine.

    Science.gov (United States)

    Liang, Xiaojing; Wang, Licheng; Wang, Shuai; Li, Yijing; Guo, Yong

    2017-11-01

    Packed cartridges have been widely used in solid-phase extraction. However, there are still some drawbacks, such as they are blocked easily and the method is time-consuming. In view of the advantages of monoliths, a monolithic extraction material has been directly synthesized in a glass syringe without any gap between the monolith and syringe inner wall. The monolithic syringe was modified with graphene oxide by loading graphene oxide dispersion onto it. The content of graphene oxide and the surface topography of the monolith have been evaluated by elemental analysis and scanning electron microscopy, respectively, which confirmed the successful modification. This prepared graphene oxide-modified monolithic syringe was directly used as a traditional solid-phase extraction cartridge. As expected, it shows good permeability and excellent capability for the extraction of quaternary ammonium alkaloids. The sample loading velocity (1-6 mL/min) does not affect the recovery. Under the optimal conditions, good linearities (R = 0.9992-0.9998) were obtained for five quaternary ammonium alkaloids, and the limits of detection and quantification were 0.5-1 and 1-2 μg/L, respectively. The proposed method was successfully applied for the analysis of quaternary ammonium alkaloids in Chinese patent medicine. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Thermal transitions in Fe-Ti-Cr-C quaternary system used as precursor during laser in situ carbide coating

    International Nuclear Information System (INIS)

    Singh, Anshul; Porter, Wallace D.; Dahotre, Narendra B.

    2005-01-01

    The temperature range of thermal transitions within the quaternary system (Fe, Ti, Cr, and C) and the thermal stability of the evolved phases were studied with the help of differential scanning calorimetry (DSC). DSC studies indicated that the major exothermic reactions (formation of carbides) take place within 850-1150 deg. C. The evolved phases (TiC, M 7 C 3 , Fe-Cr, and Fe 3 C) were characterized using X-ray diffraction (XRD). This multicomponent powder mixture was used as a precursor for synthesizing a composite coating on the surface of steel via laser surface engineering (LSE). The intended wear applications of the coating made thermal stability investigations vital. Experimental evaluation of thermal stability of the phases formed was done

  14. Quaternary Alkylammonium Conjugates of Steroids: Synthesis, Molecular Structure, and Biological Studies

    Directory of Open Access Journals (Sweden)

    Bogumił Brycki

    2015-11-01

    Full Text Available The methods of synthesis as well as physical, spectroscopic (1H-NMR, 13C-NMR, and FT-IR, ESI-MS, and biological properties of quaternary and dimeric quaternary alkylammonium conjugates of steroids are presented. The results were contrasted with theoretical calculations (PM5 methods and potential pharmacological properties (PASS. Alkylammonium sterols exhibit a broad spectrum of antimicrobial activity comparable to squalamine.

  15. Palladium-Catalyzed Asymmetric Quaternary Stereocenter Formation

    NARCIS (Netherlands)

    Gottumukkala, Aditya L.; Matcha, Kiran; Lutz, Martin; de Vries, Johannes G.; Minnaard, Adriaan J.

    2012-01-01

    An efficient palladium catalyst is presented for the formation of benzylic quaternary stereocenters by conjugate addition of arylboronic acids to a variety of beta,beta-disubstituted carbocyclic, heterocyclic, and acyclic enones. The catalyst is readily prepared from PdCl2, PhBOX, and AgSbF6, and

  16. Palladium-catalyzed asymmetric quaternary stereocenter formation

    NARCIS (Netherlands)

    Gottumukkala, A.L.; Matcha, K.; Lutz, M.; de Vries, J.G.; Minnaard, A.J.

    2012-01-01

    An efficient palladium catalyst is presented for the formation of benzylic quaternary stereocenters by conjugate addition of arylboronic acids to a variety of β,β-disubstituted carbocyclic, heterocyclic, and acyclic enones. The catalyst is readily prepared from PdCl2, PhBOX, and AgSbF6, and provides

  17. Quaternary ground siting technology of nuclear power plants

    International Nuclear Information System (INIS)

    Nishi, K.; Kokusho, T.; Iwatate, Y.; Ishida, K.; Honsho, S.; Okamoto, T.; Tohma, J.; Tanaka, Y.; Kanatani, M.

    1992-01-01

    A seismic stability evaluation method for a nuclear power plant to be located on Quaternary sandy/gravelly ground is discussed herein in terms of a geological and geotechnical survey, a design earthquake motion evaluation and geotechnical seismic stability analyses. The geological and geotechnical exploration tunnel in the rock foundation siting will be difficult in the Quaternary ground siting. Boring, geophysical surveys and soil sampling will play a major role in this case. A design earthquake input spectrum for this siting is proposed to take in account the significant effect of longer period motion on ground stability. Equivalent and non-linear analyses demonstrate the seismic stability of the foundation ground so long as the soil density is high. (author)

  18. Newly developed chitosan-silver hybrid nanoparticles: biosafety and apoptosis induction in HepG2 cells

    International Nuclear Information System (INIS)

    El-Sherbiny, Ibrahim M.; Salih, Ehab; Yassin, Abdelrahman M.; Hafez, Elsayed E.

    2016-01-01

    The present study reports the biosafety assessment, the exact molecular effects, and apoptosis induction of newly developed chitosan-silver hybrid nanoparticles (Cs–Ag NPs) in HepG2 cells. The investigated hybrid NPs were green synthesized using Cs/grape leaves aqueous extract (Cs/GLE) or Cs/GLE NPs as reducing and stabilizing agents. The successful formation of Cs/GLE NPs and Cs–Ag hybrid NPs has been confirmed by UV–Vis spectrophotometry, FTIR spectroscopy, XRD, and HRTEM. From the TEM analysis, the prepared Cs/GLE NPs are uniform and spherical with an average size of 150 nm, and the AgNPs (5–10 nm) were formed mainly on their surface. The UV–Vis spectra of Cs–Ag NPs showed a surface plasmon resonance (SPR) peak at about 450 nm confirming their formation. The synthesized Cs–Ag NPs were found to be crystalline as shown by XRD patterns with fcc phase oriented along the (111), (200), (220), and (311) planes. The cytotoxicity patterns, the antiproliferative activities, and the possible mechanisms of anticancer activity at molecular level of the newly developed Cs–Ag hybrid NPs were investigated. Cytotoxicity patterns of all the preparations demonstrated that the nontoxic treatment concentrations are ranged from 0.39 to 50 %, and many of the newly prepared Cs–Ag hybrid NPs showed high anticancer activities against HpG2 cells, and induced cellular apoptosis by downregulating BCL2 gene and upregulating P53.Graphical Abstract

  19. Newly developed chitosan-silver hybrid nanoparticles: biosafety and apoptosis induction in HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    El-Sherbiny, Ibrahim M., E-mail: ielsherbiny@Zewailcity.edu.eg; Salih, Ehab [Zewail City of Science and Technology, Center for Materials Science (Egypt); Yassin, Abdelrahman M. [Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technology Applications, Biopharmaceutical Product Research Department (Egypt); Hafez, Elsayed E. [City of Scientific Research and Technology Applications, Plant Protection and Biomolecular Diagnosis Department (Egypt)

    2016-07-15

    The present study reports the biosafety assessment, the exact molecular effects, and apoptosis induction of newly developed chitosan-silver hybrid nanoparticles (Cs–Ag NPs) in HepG2 cells. The investigated hybrid NPs were green synthesized using Cs/grape leaves aqueous extract (Cs/GLE) or Cs/GLE NPs as reducing and stabilizing agents. The successful formation of Cs/GLE NPs and Cs–Ag hybrid NPs has been confirmed by UV–Vis spectrophotometry, FTIR spectroscopy, XRD, and HRTEM. From the TEM analysis, the prepared Cs/GLE NPs are uniform and spherical with an average size of 150 nm, and the AgNPs (5–10 nm) were formed mainly on their surface. The UV–Vis spectra of Cs–Ag NPs showed a surface plasmon resonance (SPR) peak at about 450 nm confirming their formation. The synthesized Cs–Ag NPs were found to be crystalline as shown by XRD patterns with fcc phase oriented along the (111), (200), (220), and (311) planes. The cytotoxicity patterns, the antiproliferative activities, and the possible mechanisms of anticancer activity at molecular level of the newly developed Cs–Ag hybrid NPs were investigated. Cytotoxicity patterns of all the preparations demonstrated that the nontoxic treatment concentrations are ranged from 0.39 to 50 %, and many of the newly prepared Cs–Ag hybrid NPs showed high anticancer activities against HpG2 cells, and induced cellular apoptosis by downregulating BCL2 gene and upregulating P53.Graphical Abstract.

  20. Ecological impacts of the late Quaternary megaherbivore extinctions.

    Science.gov (United States)

    Gill, Jacquelyn L

    2014-03-01

    As a result of the late Quaternary megafaunal extinctions (50,000-10,000 before present (BP)), most continents today are depauperate of megaherbivores. These extinctions were time-transgressive, size- and taxonomically selective, and were caused by climate change, human hunting, or both. The surviving megaherbivores often act as ecological keystones, which was likely true in the past. In spite of this and extensive research on the causes of the Late Quaternary Extinctions, the long-term ecological consequences of the loss of the Pleistocene megafauna remained unknown until recently, due to difficulties in linking changes in flora and fauna in paleorecords. The quantification of Sporormiella and other dung fungi have recently allowed for explicit tests of the ecological consequences of megafaunal extirpations in the fossil pollen record. In this paper, I review the impacts of the loss of keystone megaherbivores on vegetation in several paleorecords. A growing number of studies support the hypothesis that the loss of the Pleistocene megafauna resulted in cascading effects on plant community composition, vegetation structure and ecosystem function, including increased fire activity, novel communities and shifts in biomes. Holocene biota thus exist outside the broader evolutionary context of the Cenozoic, and the Late Quaternary Extinctions represent a regime shift for surviving plant and animal species.

  1. Poly(3,4-ethylenedioxythiophene)-Poly(styrenesulfonate) Interlayer Insertion Enables Organic Quaternary Memory.

    Science.gov (United States)

    Cheng, Xue-Feng; Hou, Xiang; Qian, Wen-Hu; He, Jing-Hui; Xu, Qing-Feng; Li, Hua; Li, Na-Jun; Chen, Dong-Yun; Lu, Jian-Mei

    2017-08-23

    Herein, for the first time, quaternary resistive memory based on an organic molecule is achieved via surface engineering. A layer of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) was inserted between the indium tin oxide (ITO) electrode and the organic layer (squaraine, SA-Bu) to form an ITO/PEDOT-PSS/SA-Bu/Al architecture. The modified resistive random-access memory (RRAM) devices achieve quaternary memory switching with the highest yield (∼41%) to date. Surface morphology, crystallinity, and mosaicity of the deposited organic grains are greatly improved after insertion of a PEDOT-PSS interlayer, which provides better contacts at the grain boundaries as well as the electrode/active layer interface. The PEDOT-PSS interlayer also reduces the hole injection barrier from the electrode to the active layer. Thus, the threshold voltage of each switching is greatly reduced, allowing for more quaternary switching in a certain voltage window. Our results provide a simple yet powerful strategy as an alternative to molecular design to achieve organic quaternary resistive memory.

  2. Evolutionary selection of enzymatically synthesized semiconductors from biomimetic mineralization vesicles.

    Science.gov (United States)

    Bawazer, Lukmaan A; Izumi, Michi; Kolodin, Dmitriy; Neilson, James R; Schwenzer, Birgit; Morse, Daniel E

    2012-06-26

    The way nature evolves and sculpts materials using proteins inspires new approaches to materials engineering but is still not completely understood. Here, we present a cell-free synthetic biological platform to advance studies of biologically synthesized solid-state materials. This platform is capable of simultaneously exerting many of the hierarchical levels of control found in natural biomineralization, including genetic, chemical, spatial, structural, and morphological control, while supporting the evolutionary selection of new mineralizing proteins and the corresponding genetically encoded materials that they produce. DNA-directed protein expression and enzymatic mineralization occur on polystyrene microbeads in water-in-oil emulsions, yielding synthetic surrogates of biomineralizing cells that are then screened by flow sorting, with light-scattering signals used to sort the resulting mineralized composites differentially. We demonstrate the utility of this platform by evolutionarily selecting newly identified silicateins, biomineralizing enzymes previously identified from the silica skeleton of a marine sponge, for enzyme variants capable of synthesizing silicon dioxide (silica) or titanium dioxide (titania) composites. Mineral composites of intermediate strength are preferentially selected to remain intact for identification during cell sorting, and then to collapse postsorting to expose the encoding genes for enzymatic DNA amplification. Some of the newly selected silicatein variants catalyze the formation of crystalline silicates, whereas the parent silicateins lack this ability. The demonstrated bioengineered route to previously undescribed materials introduces in vitro enzyme selection as a viable strategy for mimicking genetic evolution of materials as it occurs in nature.

  3. Evaluation of quaternary aquifer between qena and luxur. (Nile Valley, Egypt)

    OpenAIRE

    Mohamaden, Mahmoud Ismail Ismail [محمود اسماعيل اسماعيل محمدين

    2001-01-01

    In order to evaluate the hydrogeological setting of the Quaternary aquifer and the related geological structures controlling its characteristics. A total of 50 vertical electrical soundings (VES.s) were conducted along 13 profiles covering the area between Qena and Luxur. As revealed from the present study, the Quaternary section in the area is subdivided into four main geoelectrical zones distributed irregularly in the study area: Zone (A) with very high electrical resistivity values rang...

  4. The Gediz River fluvial archive : A benchmark for Quaternary research in Western Anatolia

    NARCIS (Netherlands)

    Maddy, D.; Veldkamp, A.; Demir, T.; van Gorp, W.; Wijbrans, J.R.; van Hinsbergen, D.J.J.; Dekkers, M.J.; Schreve, D.; Schoorl, J.M.; Scaife, R.; Stemerdink, C.; van der Schriek, T.; Bridgland, D.R.; Aytaç, A.S.

    2017-01-01

    The Gediz River, one of the principal rivers of Western Anatolia, has an extensive Pleistocene fluvial archive that potentially offers a unique window into fluvial system behaviour on the western margins of Asia during the Quaternary. In this paper we review our work on the Quaternary Gediz River

  5. Quaternary Tectonic and Climatic Processes shaping the Central Andean hyperarid forearc (southern Peru)

    Science.gov (United States)

    Audin, Laurence; Benavente, Carlos; Zerathe, Swann; Saillard, Marianne; Hall, Sarah R.; Farber, Daniel L.

    2015-04-01

    Understanding the forearc structure and processes related to Quaternary evolution and uplift of the Western Andean Cordillera remains an outstanding scientific issue. Models of Andean Plateau evolution based on Tertiary volcanic stratigraphy since 5Ma suggest that the deformation was focused along the eastern margin of the plateau and that minimal uplift occurred along the Pacific margin. On the contrary, new tectonic data and Quaternary surface 10Be dating highlight the presence of recently active deformation, incision and alluvial processes within the upper Andean forearc together with a regional uplift of the coastal zone. Additionally, the high obliquity observed in the northern Arica Bend region makes it an ideal target to discuss whether partitioning of the oblique convergence is accommodated by the neotectonic features that dissect the Quaternary forearc. Our goals are both to decipher the Quaternary tectonic and climatic processes shaping the hyperarid forearc along strike and across strike. Finally, we aim to quantify the respective influence of these factors in the overall uplift of the Western Andes. Indeed, sequences of pediment surfaces, landslide products, paleolake deposits and marine terraces found along the oblique Peruvian margin are a unique set of datable markers that can be used to quantify the rates of Quaternary processes. In this study, we focus on the southern Peru hyperarid Atacama area where regional surfaces and tectonic markers (scarps, folds, temporary streams and paleolake levels offsets…) are well preserved for the Quaternary timescale. Numerous landsliding events align on the major fault segments and reflect Plio-Pleistocene climatic and tectonic activity together with filled and strath terraces. As the present day sea-level is one of the highest levels recorded for Quaternary time span, any emerged marine terrace is preserved by tectonic coastal uplift. In particular, the geomorphic and chronologic correlation between marine and

  6. Quaternary epitopes of α345(IV) collagen initiate Alport post-transplant anti-GBM nephritis

    DEFF Research Database (Denmark)

    Olaru, Florina; Luo, Wentian; Wang, Xu-Ping

    2013-01-01

    Alport post-transplant nephritis (APTN) is an aggressive form of anti-glomerular basement membrane disease that targets the allograft in transplanted patients with X-linked Alport syndrome. Alloantibodies develop against the NC1 domain of α5(IV) collagen, which occurs in normal kidneys, including...... of alloantibodies against allogeneic collagen IV. Some alloantibodies targeted alloepitopes within α5NC1 monomers, shared by α345NC1 and α1256NC1 hexamers. Other alloantibodies specifically targeted alloepitopes that depended on the quaternary structure of α345NC1 hexamers. In Col4a5-null mice, immunization...... with native forms of allogeneic collagen IV exclusively elicited antibodies to quaternary α345NC1 alloepitopes, whereas alloimmunogens lacking native quaternary structure elicited antibodies to shared α5NC1 alloepitopes. These results imply that quaternary epitopes within α345NC1 hexamers may initiate...

  7. Thermally Reduced Graphene Oxide Electrochemically Activated by Bis-Spiro Quaternary Alkyl Ammonium for Capacitors.

    Science.gov (United States)

    He, Tieshi; Meng, Xiangling; Nie, Junping; Tong, Yujin; Cai, Kedi

    2016-06-08

    Thermally reduced graphene oxide (RGO) electrochemically activated by a quaternary alkyl ammonium-based organic electrolytes/activated carbon (AC) electrode asymmetric capacitor is proposed. The electrochemical activation process includes adsorption of anions into the pores of AC in the positive electrode and the interlayer intercalation of cations into RGO in the negative electrode under high potential (4.0 V). The EA process of RGO by quaternary alkyl ammonium was investigated by X-ray diffraction and electrochemical measurements, and the effects of cation size and structure were extensively evaluated. Intercalation by quaternary alkyl ammonium demonstrates a small degree of expansion of the whole crystal lattice (d002) and a large degree of expansion of the partial crystal lattice (d002) of RGO. RGO electrochemically activated by bis-spiro quaternary alkyl ammonium in propylene carbonate/AC asymmetric capacitor exhibits good activated efficiency, high specific capacity, and stable cyclability.

  8. A major change in precipitation gradient on the Chinese Loess Plateau at the Pliocene-Quaternary boundary

    Science.gov (United States)

    Peng, Wenbin; Nie, Junsheng; Wang, Zhao; Qiang, Xiaoke; Garzanti, Eduardo; Pfaff, Katharina; Song, Yougui; Stevens, Thomas

    2018-04-01

    Spatiotemporal variations in East Asian Monsoon (EAM) precipitation during the Quaternary have been intensively studied. However, spatial variations in pre-Quaternary EAM precipitation remain largely uninvestigated, preventing a clear understanding of monsoon dynamics during a warmer climatic period. Here we compare the spatial differences in heavy mineral assemblages between Quaternary loess and pre-Quaternary Red Clay on the Chinese Loess Plateau (CLP) to analyze spatial patterns in weathering. Prior studies have revealed that unstable hornblende is the dominant (∼50%) heavy mineral in Chinese loess deposited over the past 500 ka, whereas hornblende content decreases to climate at Jiaxian must have been initiated since ∼2.7 Ma, preventing hornblende dissolution to amounts change in climatic patterns at ∼2.7 Ma to decreased northward moisture transportation associated with Northern Hemisphere glaciation and cooling in the Quaternary. This study therefore demonstrates the potential usefulness of employing heavy mineral analysis in both paleoclimatic and paleooceanographic reconstructions.

  9. Geo-Electric and Hydrogeochemical Mapping of Quaternary ...

    African Journals Online (AJOL)

    Michael Horsfall

    basically different from those observed in nearby Warri and indicative of possible ... exist in the Quaternary superficial deposits of the Niger Delta environment. ... the petroleum geology of the area has been subject of ... of Commerce and Industry, 2001; Atakpo and ... purposes of aquifer vulnerability assessments and the.

  10. Nano magnetic solid phase extraction for preconcentration of lead ions in environmental samples by a newly synthesized reagent.

    Science.gov (United States)

    Golshekan, Mostafa; Shariati, Shahab

    2013-01-01

    In this study, magnetite nanoparticles with particle size lower than 47 nm were synthesized and were applied for preconcentration of Pb2+ ions from aqueous solutions. To preconcentrate the Pb2+ ions, the surface of the synthesized nano particles was modified with sodium dodecyl sulfate (SDS) as an anionic surfactant. A new chelating agent (2-((E)-2-amino-4,5-dinitrophenylimino)methyl)phenol) was synthesized and used to form a very stable complex with Pb2+ ions. The lead ions formed complexes and were quantitatively extracted with SDS-coated magnetite nanoparticles. After magnetic separation of adsorbent, the adsorbent was eluted with 0.5% (v/v) HC1 in dimethyl sulfoxide (DMSO) prior to analysis by flame atomic absorption spectrometry (FAAS). Orthogonal array design (OAD) was used to study and optimize the different experimental parameters. Under the optimum conditions, enhancement factor up to 63.5 was achieved for extraction from only 10 mL of sample solution and the relative standard deviation (RSD %) of the method was lower than 2.8%. The obtained calibration curve was linear in the range of 1-300 pg L-' with reasonable linearity (r2 > 0.998). The limit of detection (LOD) based on S/N = 3 was 0.04 microg L(-1) for 10 mL sample volumes. Finally, applicability of the proposed method was successfully confirmed by preconcentration and determination of trace amounts of lead ions in environmental samples and satisfactory results were obtained.

  11. Derivatization of peptides as quaternary ammonium salts for sensitive detection by ESI-MS.

    Science.gov (United States)

    Cydzik, Marzena; Rudowska, Magdalena; Stefanowicz, Piotr; Szewczuk, Zbigniew

    2011-06-01

    A series of model peptides in the form of quaternary ammonium salts at the N-terminus was efficiently prepared by the solid-phase synthesis. Tandem mass spectrometric analysis of the peptide quaternary ammonium derivatives was shown to provide sequence confirmation and enhanced detection. We designed the 2-(1,4-diazabicyclo[2.2.2] octylammonium)acetyl quaternary ammonium group which does not suffer from neutral losses during MS/MS experiments. The presented quaternization of 1,4-diazabicyclo[2.2.2]octane (DABCO) by iodoacetylated peptides is relatively easy and compatible with standard solid-phase peptide synthesis. This methodology offers a novel sensitive approach to analyze peptides and other compounds. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.

  12. Seismic stability analyses of various reactor buildings on quaternary deposit

    International Nuclear Information System (INIS)

    Takeuchi, Y.; Tsutagawa, M.; Asakura, S.; Katoh, T.; Tomura, H.; Uchiyama, S.; Koyama, M.; Oguro, E.; Akino, K.; Iizuka, S.; Hayashi, M.

    1993-01-01

    Many nuclear power plants have been built on Quaternary deposits in Europe and U.S.A., however, Japanese basic policy is to construct the reactor building and other auxiliary buildings on a bed rock which are important to safety, because large earthquakes are postulated to occur. Being limited bed rock sites in Japan, it has become necessary to increase possible place for nuclear power plant in order to cope with the middle and long term siting problems. For the purpose of establishing the draft of guideline on seismic design of reactor building on the Quaternary sand and gravel deposit in Japan, foundation soil stability and seismic resistance of the reactor building and plant equipment have been investigated and studied from 1983 to 1998. The studies have shown the following: 1) The response rotation angles of both common light weight basement (CL) and step basement (ES) plants during the earthquake reduce to 1/2 of the BR plant value, and the bearing pressure between the basement and the soil of improved plant are reduced as well; (2) every structure built on quaternary sand and gravel deposit, having 400m/s shear velocity, maintains enough seismic resistance, because the shear stress caused in the wall is small. The maximum shear strain of soil below the basemat of BR-BWR, which suffers the largest bearing pressure, is 1.1x10 -9 , but it can be said that the soil has enough stability according to the past soil tests for the Quaternary sand and gravel deposit that had been done by authors

  13. Synthesis of Tertiary and Quaternary Amine Derivatives from Wood Resin as Chiral NMR Solvating Agents

    Directory of Open Access Journals (Sweden)

    Tiina Laaksonen

    2015-11-01

    Full Text Available Chiral tertiary and quaternary amine solvating agents for NMR spectroscopy were synthesized from the wood resin derivative (+-dehydroabietylamine (2. The resolution of enantiomers of model compounds [Mosher’s acid (3 and its n-Bu4N salt (4] (guests by (+-dehydroabietyl-N,N-dimethylmethanamine (5 and its ten different ammonium salts (hosts was studied. The best results with 3 were obtained using 5 while with 4 the best enantiomeric resolution was obtained using (+-dehydroabietyl-N,N-dimethylmethanaminium bis(trifluoromethane-sulfonimide (6. The compounds 5 and 6 showed a 1:1 complexation behaviour between the host and guest. The capability of 5 and 6 to recognize the enantiomers of various α-substituted carboxylic acids and their n-Bu4N salts in enantiomeric excess (ee determinations was demonstrated. A modification of the RES-TOCSY NMR pulse sequence is described, allowing the enhancement of enantiomeric discrimination when the resolution of multiplets is insufficient.

  14. Quaternary tectonic evolution of the Pamir-Tian Shan convergence zone, Northwest China

    Science.gov (United States)

    Thompson Jobe, Jessica Ann; Li, Tao; Chen, Jie; Burbank, Douglas W.; Bufe, Aaron

    2017-12-01

    The Pamir-Tian Shan collision zone in the western Tarim Basin, northwest China, formed from rapid and ongoing convergence in response to the Indo-Eurasian collision. The arid landscape preserves suites of fluvial terraces crossing structures active since the late Neogene that create fault and fold scarps recording Quaternary deformation. Using geologic and geomorphic mapping, differential GPS surveys of deformed terraces, and optically stimulated luminescence dating, we create a synthesis of the active structures that delineate the timing, rate, and migration of Quaternary deformation during ongoing convergence. New deformation rates on eight faults and folds, when combined with previous studies, highlight the spatial and temporal patterns of deformation within the Pamir-Tian Shan convergence zone during the Quaternary. Terraces spanning 130 to 8 ka record deformation rates between 0.1 and 5.6 mm/yr on individual structures. In the westernmost Tarim Basin, where the Pamir and Tian Shan are already juxtaposed, the fastest rates occur on actively deforming structures at the interface of the Pamir-Tian Shan orogens. Farther east, as the separation between the Pamir-Tian Shan orogens increases, the deformation has not been concentrated on a single structure, but rather has been concurrently distributed across a zone of faults and folds in the Kashi-Atushi fold-and-thrust belt and along the NE Pamir margin, where shortening rates vary on individual structures during the Quaternary. Although numerous structures accommodate the shortening and the locus of deformation shifts during the Quaternary, the total shortening across the western Tarim Basin has remained steady and approximately matches the current geodetic rate of 6-9 mm/yr.

  15. Late Quaternary changes in surface productivity and oxygen ...

    Indian Academy of Sciences (India)

    University of Allahabad, Allahabad 211 002, India. ∗ e-mail: ... This process lowers the pH of water which results into increased dissolution of ..... causes a rapid melting of the inland glaciers, an .... Quaternary climate changes; J. Atmos. Sci.

  16. Potentiometric studies on quaternary complexes of dioxouranium(VI)

    Energy Technology Data Exchange (ETDEWEB)

    Kumari, Vinod; Chaturvedi, G K [Agra Coll., (India). Chemical Laboratories

    1979-10-01

    The formation of quaternary complexes of dioxouranium(VI) with three different organic acids (OX, MALN and SA, SSA, TAR or TMA) has been inferred from the potentiometric studies. The formation constants for the resulting triligand complexes have been evaluated.

  17. Thermoelectric performance of tellurium-reduced quaternary p-type lead–chalcogenide composites

    International Nuclear Information System (INIS)

    Aminorroaya Yamini, Sima; Wang, Heng; Gibbs, Zachary M.; Pei, Yanzhong; Mitchell, David R.G.; Dou, Shi Xue; Snyder, G. Jeffrey

    2014-01-01

    Graphical abstract: - Abstract: A long-standing technological challenge to the widespread application of thermoelectric generators is obtaining high-performance thermoelectric materials from abundant elements. Intensive study on PbTe alloys has resulted in a high figure of merit for the single-phase ternary PbTe–PbSe system through band structure engineering, and the low thermal conductivity achieved due to nanostructuring leads to high thermoelectric performance for ternary PbTe–PbS compounds. Recently, the single-phase p-type quaternary PbTe–PbSe–PbS alloys have been shown to provide thermoelectric performance superior to the binary and ternary lead chalcogenides. This occurs via tuning of the band structure and from an extraordinary low thermal conductivity resulting from high-contrast atomic mass solute atoms. Here, we present the thermoelectric efficiency of nanostructured p-type quaternary PbTe–PbSe–PbS composites and compare the results with corresponding single-phase quaternary lead chalcogenide alloys. We demonstrate that the very low lattice thermal conductivity achieved is attributed to phonon scattering at high-contrast atomic mass solute atoms rather than from the contribution of secondary phases. This results in a thermoelectric efficiency of ∼1.4 over a wide temperature range (650–850 K) in a p-type quaternary (PbTe) 0.65 (PbSe) 0.1 (PbS) 0.25 composite that is lower than that of single-phase (PbTe) 0.85 (PbSe) 0.1 (PbS) 0.05 alloy without secondary phases

  18. A quaternary lead based perovskite structured materials with diffuse phase transition behavior

    International Nuclear Information System (INIS)

    Puli, Venkata Sreenivas; Martínez, R.; Kumar, Ashok; Scott, J.F.; Katiyar, Ram S.

    2011-01-01

    Graphical abstract: (a) Curie–Weiss plot for the inverse of the relative dielectric permittivity and (b) log (1/ε − 1/ε m ) as function of log (T − T m ) for ceramics at 1 kHz. Highlights: ► Retaining phase pure structure with quaternary complex stoichiometric compositions. ► P–E loops with good saturation polarization (P s ∼ 30.7 μC/cm 2 ). ► Diffused relaxor phase transition behavior with γ estimated is ∼1.65. -- Abstract: A lead based quaternary compound composed of 0.25(PbZr 0.52 Ti 0.48 O 3 ) + 0.25(PbFe 0.5 Ta 0.5 O 3 ) + 0.25 (PbF 0.67 W 0.33 O 3 ) + 0.25(PbFe 0.5 Nb 0.5 O 3 ) – (PZT–PFT–PFW–PFN) was synthesized by conventional solid-state reaction techniques. It showed moderate high dielectric constant, low dielectric loss, and two diffuse phase transitions, one below the room temperature ∼261 K and other above ∼410 K. X-ray diffraction (XRD) patterns revealed a tetragonal crystal structure at room temperature where as scanning electron micrograph (SEM) indicates inhomogeneous surface with an average grain size of 500 nm–3 μm. Well saturated ferroelectric hysteresis loops with good saturation polarization (spontaneous polarization, P s ∼ 30.68 μC/cm 2 ) were observed. Temperature-dependent ac conductivity displayed low conductivity with kink in spectra near the phase transition. In continuing search for developing new ferroelectric materials, in the present study we report stoichiometric compositions of complex perovskite ceramic materials: (PZT–PFT–PFW–PFN) with diffuse phase transition behavior. The crystal structure, dielectric properties, and ferroelectric properties were characterized by XRD, SEM, dielectric spectroscopy, and polarization. 1/ε versus (T) plots revealed diffuse relaxor phase transition (DPT) behavior. The compositional variation on the phase transition temperature, dielectric constant, and ferroelectric to paraelectric phase transitions are discussed.

  19. A quaternary lead based perovskite structured materials with diffuse phase transition behavior

    Energy Technology Data Exchange (ETDEWEB)

    Puli, Venkata Sreenivas, E-mail: pvsri123@gmail.com [Department of Physics and Institute for Functional Nano Materials, University of Puerto Rico, San Juan, PR 00936 (United States); Martinez, R.; Kumar, Ashok [Department of Physics and Institute for Functional Nano Materials, University of Puerto Rico, San Juan, PR 00936 (United States); Scott, J.F. [Department of Physics and Institute for Functional Nano Materials, University of Puerto Rico, San Juan, PR 00936 (United States); Cavendish Laboratory, Dept. Physics, University of Cambridge, Cambridge CB0 3HE (United Kingdom); Katiyar, Ram S., E-mail: rkatiyar@uprrp.edu [Department of Physics and Institute for Functional Nano Materials, University of Puerto Rico, San Juan, PR 00936 (United States)

    2011-12-15

    Graphical abstract: (a) Curie-Weiss plot for the inverse of the relative dielectric permittivity and (b) log (1/{epsilon} - 1/{epsilon}{sub m}) as function of log (T - T{sub m}) for ceramics at 1 kHz. Highlights: Black-Right-Pointing-Pointer Retaining phase pure structure with quaternary complex stoichiometric compositions. Black-Right-Pointing-Pointer P-E loops with good saturation polarization (P{sub s} {approx} 30.7 {mu}C/cm{sup 2}). Black-Right-Pointing-Pointer Diffused relaxor phase transition behavior with {gamma} estimated is {approx}1.65. -- Abstract: A lead based quaternary compound composed of 0.25(PbZr{sub 0.52}Ti{sub 0.48}O{sub 3}) + 0.25(PbFe{sub 0.5}Ta{sub 0.5}O{sub 3}) + 0.25 (PbF{sub 0.67}W{sub 0.33}O{sub 3}) + 0.25(PbFe{sub 0.5}Nb{sub 0.5}O{sub 3}) - (PZT-PFT-PFW-PFN) was synthesized by conventional solid-state reaction techniques. It showed moderate high dielectric constant, low dielectric loss, and two diffuse phase transitions, one below the room temperature {approx}261 K and other above {approx}410 K. X-ray diffraction (XRD) patterns revealed a tetragonal crystal structure at room temperature where as scanning electron micrograph (SEM) indicates inhomogeneous surface with an average grain size of 500 nm-3 {mu}m. Well saturated ferroelectric hysteresis loops with good saturation polarization (spontaneous polarization, P{sub s} {approx} 30.68 {mu}C/cm{sup 2}) were observed. Temperature-dependent ac conductivity displayed low conductivity with kink in spectra near the phase transition. In continuing search for developing new ferroelectric materials, in the present study we report stoichiometric compositions of complex perovskite ceramic materials: (PZT-PFT-PFW-PFN) with diffuse phase transition behavior. The crystal structure, dielectric properties, and ferroelectric properties were characterized by XRD, SEM, dielectric spectroscopy, and polarization. 1/{epsilon} versus (T) plots revealed diffuse relaxor phase transition (DPT) behavior. The

  20. Fluorosilicone multi-block copolymers tethering quaternary ammonium salt groups for antimicrobial purpose

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Fang; Qin, Xiaoshuai; Li, Yancai; Ren, Lixia; Zhao, Yunhui, E-mail: zhaoyunhui@tju.edu.cn; Yuan, Xiaoyan

    2015-08-30

    Highlights: • QAS-containing fluorosilicone multi-block copolymers were synthesized. • The block length of PHFBMA in the copolymers was tailored via RAFT polymerization. • Surface roughness of the copolymers decreased with the increased PHFBMA content. • A certain length of PHFBMA block enhanced C−N{sup +} percentage on the surface. - Abstract: Symmetrically structured fluorosilicone multi-block copolymers containing poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and poly(hexafluorobutyl methacrylate) (PHFBMA) were sequentially synthesized via reversible addition–fragmentation chain transfer polymerization, using a polydimethylsiloxane (PDMS) chain transfer agent with dithiocarbonate groups at both ends. Then, the CBABC-type block copolymers were quaternized with n-octyliodide to tether quaternary ammonium salt (QAS) groups in the PDMAEMA blocks for the antimicrobial use. The obtained fluorosilicone copolymers showed clear variations in the C-N{sup +} composition and surface morphology on their films depending on the content of the PHFBMA blocks, which were characterized by X-ray photoelectron spectroscopy and atomic force microscopy, respectively. The results indicated that the symmetrical CBABC structure favored PDMS and QAS tethered blocks migrating to the film surface. With the mass percentage of the PHFBMA increased from 0 to 32.5%, the surface roughness of the copolymer film decreased gradually with a tendency to form a smooth surface. Owing to the surface properties, fluorosilicone multi-block copolymers containing a certain amount of PHFBMA with higher C-N{sup +} content and relatively smooth morphology demonstrated obvious antimicrobial activity against Gram-positive bacteria, Bacillus subtilis and Gram-negative bacteria, Escherichia coli. The functionalized multi-block copolymers based on fluorosilicone and QAS groups would have potential applications in antimicrobial coatings.

  1. Fluorosilicone multi-block copolymers tethering quaternary ammonium salt groups for antimicrobial purpose

    International Nuclear Information System (INIS)

    Zhou, Fang; Qin, Xiaoshuai; Li, Yancai; Ren, Lixia; Zhao, Yunhui; Yuan, Xiaoyan

    2015-01-01

    Highlights: • QAS-containing fluorosilicone multi-block copolymers were synthesized. • The block length of PHFBMA in the copolymers was tailored via RAFT polymerization. • Surface roughness of the copolymers decreased with the increased PHFBMA content. • A certain length of PHFBMA block enhanced C−N + percentage on the surface. - Abstract: Symmetrically structured fluorosilicone multi-block copolymers containing poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and poly(hexafluorobutyl methacrylate) (PHFBMA) were sequentially synthesized via reversible addition–fragmentation chain transfer polymerization, using a polydimethylsiloxane (PDMS) chain transfer agent with dithiocarbonate groups at both ends. Then, the CBABC-type block copolymers were quaternized with n-octyliodide to tether quaternary ammonium salt (QAS) groups in the PDMAEMA blocks for the antimicrobial use. The obtained fluorosilicone copolymers showed clear variations in the C-N + composition and surface morphology on their films depending on the content of the PHFBMA blocks, which were characterized by X-ray photoelectron spectroscopy and atomic force microscopy, respectively. The results indicated that the symmetrical CBABC structure favored PDMS and QAS tethered blocks migrating to the film surface. With the mass percentage of the PHFBMA increased from 0 to 32.5%, the surface roughness of the copolymer film decreased gradually with a tendency to form a smooth surface. Owing to the surface properties, fluorosilicone multi-block copolymers containing a certain amount of PHFBMA with higher C-N + content and relatively smooth morphology demonstrated obvious antimicrobial activity against Gram-positive bacteria, Bacillus subtilis and Gram-negative bacteria, Escherichia coli. The functionalized multi-block copolymers based on fluorosilicone and QAS groups would have potential applications in antimicrobial coatings

  2. Analysis of polarized photoluminescence emission of ordered III–V semiconductor quaternary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Prutskij, Tatiana, E-mail: tatiana.prutskij@correo.buap.mx [Instituto de Ciencias, BUAP, Privada 17 Norte, No 3417, Col. San Miguel Huyeotlipan, 72050 Puebla, Pue., México (Mexico); Makarov, Nykolay, E-mail: nykolay.makarov@correo.buap.mx [Instituto de Ciencias, BUAP, Privada 17 Norte, No 3417, Col. San Miguel Huyeotlipan, 72050 Puebla, Pue., México (Mexico); Attolini, Giovanni, E-mail: giovanni@imem.cnr.it [IMEM/CNR, Parco Area delle Scienze 37/A, 43010 Parma (Italy)

    2016-04-15

    Ternary and quaternary III–V alloys obtained by metal-organic vapor-phase epitaxy (MOVPE) grow very often with some degree of atomic ordering. Atomic ordering reduces the symmetry of the crystal lattice and thus drastically changes optical properties of the alloy. Moreover, the photoluminescence (PL) emission becomes polarized and its study helps to understand the atomic arrangement within the crystal lattice. In this work we experimentally studied the polarization of the PL emission from different crystallographic planes of several quaternary III–V semiconductor alloys grown on GaAs substrates by MOVPE. We compare the measured PL emission polarization angular patterns with those calculated with a model made for ternary alloys and discuss the limits of application of this model for quaternaries. It is found that the experimentally obtained polarization patterns are consistent with the existence of different ordering crystallographic planes for III- and for V-group atoms.

  3. Cytoplasmic assembly of snRNP particles from stored proteins and newly transcribed snRNA's in L929 mouse fibroblasts

    International Nuclear Information System (INIS)

    Sauterer, R.A.; Feeney, R.J.; Zieve, G.W.

    1988-01-01

    Newly synthesized snRNAs appear transiently in the cytoplasm where they assemble into ribonucleoprotein particles, the snRNP particles, before returning permanently to the interphase nucleus. In this report, bona fide cytoplasmic fractions, prepared by cell enucleation, are used for a quantitative analysis of snRNP assembly in growing mouse fibroblasts. The half-lives and abundances of the snRNP precursors in the cytoplasm and the rates of snRNP assembly are calculated in L929 cells. With the exception of U6, the major snRNAs are stable RNA species; U1 is almost totally stable while U2 has a half-life of about two cell cycles. In contrast, the majority of newly synthesized U6 decays with a half-life of about 15 h. The relative abundances of the newly synthesized snRNA species U1, U2, U3, U4 and U6 in the cytoplasm are determined by Northern hybridization using cloned probes and are approximately 2% of their nuclear abundance. The half-lives of the two major snRNA precursors in the cytoplasm (U1 and U2) are approximately 20 min as determined by labeling to steady state. The relative abundance of the snRNP B protein in the cytoplasm is determined by Western blotting with the Sm class of autoantibodies and is approximately 25% of the nuclear abundance. Kinetic studies, using the Sm antiserum to immunoprecipitate the methionine-labeled snRNP proteins, suggest that the B protein has a half-life of 90 to 120 min in the cytoplasm. These data are discussed and suggest that there is a large pool of more stable snRNP proteins in the cytoplasm available for assembly with the less abundant but more rapidly turning-over snRNAs

  4. Positively charged gold nanoparticles capped with folate quaternary chitosan: Synthesis, cytotoxicity, and uptake by cancer cells.

    Science.gov (United States)

    Yen, Hui-Ju; Young, Yen-An; Tsai, Tsung-Neng; Cheng, Kuang-Ming; Chen, Xin-An; Chen, Ying-Chuan; Chen, Cheng-Cheung; Young, Jenn-Jong; Hong, Po-da

    2018-03-01

    In this study, we synthesized various quaternary chitosan derivatives and used them to stabilize gold nanoparticles (AuNPs). These chitosan derivatives comprised N-(2-hydroxy)propyl-3-trimethylammonium chitosan chloride (HTCC), folate-HTCC, galactosyl-HTCC, and their fluorescein isothiocyanate-conjugated derivatives. Various positively surface-charged AuNPs were prepared under alkaline conditions using glucose as a reducing agent in the presence of the HTCC derivatives (HTCCs). The effects of the concentration of NaOH, glucose, and HTCCs on the particles size, zeta potential, and stability were studied in detail. Cell cycle assays verify that none of the HTCCs or HTCCs-AuNPs was cytotoxic to human umbilical vein endothelial cells. Flow cytometry analysis showed that the folate HTCC-AuNPs were internalized in Caco-2, HepG2, and HeLa cancer cells to a significantly greater extent than AuNPs without folate. But, galactosyl HTCC-AuNPs only showed high cell uptake by HepG2 cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Recent advances in quaternary geochronology

    International Nuclear Information System (INIS)

    Poupeau, G.

    1983-01-01

    Significant progress has occurred in quaternary geochronology. These include both (i) improvements in Fission Track and Thermoluminescence dating, as well as (ii) new technologies for short-lived (i.e. with half lives 6 yrs) radionuclide measurements as with the 14 C or uranium series desequilibrium dating, and finally (iii) the emergence of entirely new dating approches as the Electron Spin Resonnance Method. The aim of this paper is to review these progresses and the new areas they open geochronology for the past-miocene times. (author) [pt

  6. Auxotrophy-stimulated sensitivity to quaternary ammonium salts and its relation to active transport in yeast

    International Nuclear Information System (INIS)

    Lachowicz, T.M.; Oblak, E.; Piatkowski, J.

    1992-01-01

    In previous studies we have observed that auxotrophic mutants of yeast were much more sensitive to quaternary ammonium salts than the corresponding isogenic wild type strains. The super sensitivity of the auxotrophs seems to be a characteristic feature of yeast and yeast-like microorganisms: the level of sensitivity of the quaternary ammonium salts of the bacterial auxotrophs and their original prototrophic forms appeared to be the same. The super sensitivity of yeast auxotrophs disappeared on minimal media with ammonium as a nitrogen source. In this report there are presented the data indicating that enrichment of the minimal medium with arginine restores the super sensitivity of auxotrophic yeast mutants to the quaternary ammonium salts. The results of amino-acid transport into the auxotrophic yeast cells treated with a quaternary ammonium salt in the presence and absence of arginine are given. A working hypothesis of the mechanism of these salts action as a specific inhibition of nutrient transport is discussed. (author). 19 refs, 3 figs, 8 figs

  7. Plio-quaternary deposits in the Eastern Rharb (Nw Morocco): Electrosequential characterization

    Science.gov (United States)

    Al Mazini, Imane; Mridekh, Abdelaziz; Kili, Malika; El Mansouri, Bouâbid; El Bouhaddioui, Mohamed; Magrane, Bouchaib

    2018-02-01

    The Rharb basin, of which our study area is part, is located at the western extremity of the south Rif corridor. It corresponds to a subsiding zone that appeared in the Upper Miocene, between two major structural domains: the Rif to the north and east and the Meseta domain to the south. The eastern part of this basin is characterized by a Plio-Quaternary continental fill. Its geographical position and its structural and paleo-environmental contexts are reflected by a great facies heterogeneity. This work aims to image the subsurface structure and to characterize the distribution mode of Plio-Quaternary deposits of the eastern Rharb. The use of a database consisting of geo-electrical cross sections, hydrogeological drilling and wireline logging integrated in a Geographic Information System (GIS) allowed us to establish a new three-dimensional model of the top of the Mio-Pliocene substratum, new geo-electrical cross sections, as well as the isopach maps of lower, intermediate, upper and superficial geo-electric interval. This approach allowed us to characterize the Plio-Quaternary deposits of the study area and to highlight the effects of the tectonic regime and the relative sea level fluctuations on the sequential organization of these deposits. Our new model shows the development of prograding, aggrading and retrograding parasequences denoting the existence of autogenic mechanisms in the organization of plio-quaternary deposits of the eastern part of the Rharb basin. Therefore, it opens new perspectives for the exploration of water resources and monitoring their quality throughout the basin.

  8. Organo-Functionalization of Silicon Nanocrystals Synthesized by Inductively Coupled Plasma Chemical Vapor Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Don-Sung; Choe, Dong-Hoe; Jeong, Hyun-Dam [Chonnam National University, Gwangju (Korea, Republic of); Yoo, Seung-Wan; Kim, Jung-Hyung [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2016-05-15

    Octadecyl-terminated silicon nanocrystals (ODE-Si NCs) are obtained via a surface-initiated thermal hydrosilylation reaction on hydride-terminated Si NCs (H-Si NCs). Pristine Si NCs were synthesized at the gram scale by using inductively coupled plasma chemical vapor deposition (ICP-CVD) . The H-Si NCs were produced through a chemical etching process with hydrofluoric acid (HF), ethanol (EtOH), and distilled water (d-H{sub 2}O). The results obtained from X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) indicate that the synthesized Si NCs obtained via ICP-CVD have diamond cubic-structured silicon with a grain size of 10 nm and a densely packed Si NC array consisting of individual NCs. Organo-functionalized Si NCs, i.e., ODE-Si NCs, are well soluble in organic solvent whereas pristine Si NCs synthesized through ICP-CVD are not. The surface chemistry of the ODE-Si NCs was confirmed via Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy ({sup 1}H-NMR), and field emission transmission electron microscopy (FE-TEM). Thereby, these newly synthesized and scalable organo-functionalized Si NCs are applicable as raw materials for practical use in devices by tuning the surface chemistry with various capping molecules.

  9. Polarization encoded all-optical quaternary R-S flip-flop using binary latch

    Science.gov (United States)

    Chattopadhyay, Tanay; Roy, Jitendra Nath; Chakraborty, Ajoy Kumar

    2009-04-01

    The developments of different multi-valued logic (MVL) systems have received considerable interests in recent years all over the world. In electronics, efforts have already been made to incorporate multi-valued system in logic and arithmetic data processing. But, very little efforts have been given in realization of MVL with optics. In this paper we present novel designs of certain all-optical circuits that can be used for realizing multi-valued logic functions. Polarization encoded all-optical quaternary (4-valued) R-S flip-flop is proposed and described. Two key circuits (all-optical encoder/decoder and a binary latch) are designed first. They are used to realize quaternary flip-flop in all-optical domain. Here the different quaternary logical states are represented by different polarized state of light. Terahertz Optical Asymmetric Demultiplexer (TOAD) based interferometric switch can take an important role. Computer simulation result confirming described methods and conclusion are given in this paper.

  10. Community ecology in a changing environment: Perspectives from the Quaternary.

    Science.gov (United States)

    Jackson, Stephen T; Blois, Jessica L

    2015-04-21

    Community ecology and paleoecology are both concerned with the composition and structure of biotic assemblages but are largely disconnected. Community ecology focuses on existing species assemblages and recently has begun to integrate history (phylogeny and continental or intercontinental dispersal) to constrain community processes. This division has left a "missing middle": Ecological and environmental processes occurring on timescales from decades to millennia are not yet fully incorporated into community ecology. Quaternary paleoecology has a wealth of data documenting ecological dynamics at these timescales, and both fields can benefit from greater interaction and articulation. We discuss ecological insights revealed by Quaternary terrestrial records, suggest foundations for bridging between the disciplines, and identify topics where the disciplines can engage to mutual benefit.

  11. QuaBingo: A Prediction System for Protein Quaternary Structure Attributes Using Block Composition

    Directory of Open Access Journals (Sweden)

    Chi-Hua Tung

    2016-01-01

    Full Text Available Background. Quaternary structures of proteins are closely relevant to gene regulation, signal transduction, and many other biological functions of proteins. In the current study, a new method based on protein-conserved motif composition in block format for feature extraction is proposed, which is termed block composition. Results. The protein quaternary assembly states prediction system which combines blocks with functional domain composition, called QuaBingo, is constructed by three layers of classifiers that can categorize quaternary structural attributes of monomer, homooligomer, and heterooligomer. The building of the first layer classifier uses support vector machines (SVM based on blocks and functional domains of proteins, and the second layer SVM was utilized to process the outputs of the first layer. Finally, the result is determined by the Random Forest of the third layer. We compared the effectiveness of the combination of block composition, functional domain composition, and pseudoamino acid composition of the model. In the 11 kinds of functional protein families, QuaBingo is 23% of Matthews Correlation Coefficient (MCC higher than the existing prediction system. The results also revealed the biological characterization of the top five block compositions. Conclusions. QuaBingo provides better predictive ability for predicting the quaternary structural attributes of proteins.

  12. Original Article. Protection studies of new bis quaternary 2-(hydroxyimino-N-(pyridin-3yl acetamide derivatives (HNK-series oximes against acute poisoning by dichlorvos (DDVP in Swiss albino mice

    Directory of Open Access Journals (Sweden)

    Kumar Pravin

    2016-12-01

    Full Text Available The available antidotal therapy against acute poisoning by organophosphates involves the use of atropine alone or in combination with one of the oximes, e.g. 2-PAM, Obidoxime, TMB-4 or HI-6. Each of these oximes has some limitation, raising the question of the universal antidotal efficacy against poisoning by all OPs/nerve agents. In the present study, newly synthesized bis quaternary 2-(hydroxyimino-N-(pyridin-3yl acetamide derivatives (HNK-series oximes were evaluated for their antidotal efficacy against DDVP intoxicated Swiss mice, in terms of the Protection Index (PI and AChE reactivation in brain and serum. The inhibition concentration (IC50 was determined in brain and serum after optimizing the time point for maximum inhibition (60 min post DDVP exposure. AChE reactivation efficacy of the HNK series was evaluated at IC50 and compared with 2-PAM. HNK-102 showed a ~2 times better Protection Index (PI as compared to 2-PAM against DDVP toxicity. IC50 at 60 min DDVP post exposure was found to be approximately one fifth and one half of the LD50 dose for brain and serum AChE, respectively. Out of three HNK oximes, HNK-102 & 106 at 0.20 LD50 dose significantly reactivated DDVP intoxicated brain AChE (p<0.05 as compared to 2-PAM at double IC50 dose of DDVP. In light of double PI and higher AChE reactivation, HNK 102 was found to be a better oxime than 2-PAM in the treatment of acute poisoning by DDVP.

  13. Fibronectin synthesized by a human hepatoma cell line

    International Nuclear Information System (INIS)

    Glasgow, J.E.; Colman, R.W.

    1984-01-01

    Fibronectin is a family of immunologically similar glycoproteins which mediate a variety of cell-cell and cell-substratum interactions. It is a constituent of the extracellular matrix of connective tissue and circulates in plasma. When suspension and adherent cultures of a human hepatoma cell line (SK-HEP-1) were incubated in serum-free medium, the resulting conditioned medium contained material which was specifically immunoprecipitated by antisera to human plasma fibronectin. By double immunodiffusion, a component in the conditioned culture medium was shown to form a line of identity with fibronectin in human plasma and to migrate as an alpha 2- to beta-globulin during immunoelectrophoresis. Human fibronectin was quantified in conditioned medium by electroimmunodiffusion, and was found to increase for at least three days at about 0.1 micrograms/10(6) cells/day. Adherent cultures of SK-HEP-1 cells were incubated with L-[ 35 S]methionine to label newly synthesized proteins. Labeled fibronectin in conditioned medium or in cell extracts comigrated with fibronectin in human plasma as shown by autoradiography following crossed-immunoelectrophoresis. Fibronectin was demonstrated in the extra-cellular matrix of adherent SK-HEP-1 cultures by immunofluorescence. It was shown previously that SK-HEP-1 cells synthesize alpha 1-protease inhibitor, one of the products of normal hepatocytes. The finding that these hepatoma cells also synthesize fibronectin supports the concept that the hepatocyte may be one source of circulating fibronectin, a possibility consistent with the established role of this cell type in blood plasma protein synthesis

  14. Characterization and bioactivity of novel calcium antagonists - N-methoxy-benzyl haloperidol quaternary ammonium salt

    Science.gov (United States)

    Chen, Yi-Cun; Zhu, Wei; Zhong, Shu-Ping; Zheng, Fu-Chun; Gao, Fen-Fei; Zhang, Yan-Mei; Xu, Han; Zheng, Yan-Shan; Shi, Gang-Gang

    2015-01-01

    BACKGROUND AND PURPOSE Calcium antagonists play an important role in clinical practice. However, most of them have serious side effects. We have synthesized a series of novel calcium antagonists, quaternary ammonium salt derivatives of haloperidol with N-p-methoxybenzyl (X1), N-m-methoxybenzyl (X2) and N-o-methoxybenzyl (X3) groups. The objective of this study was to investigate the bioactivity of these novel calcium antagonists, especially the vasodilation activity and cardiac side-effects. The possible working mechanisms of these haloperidol derivatives were also explored. EXPERIMENTAL APPROACH Novel calcium antagonists were synthesized by amination. Compounds were screened for their activity of vasodilation on isolated thoracic aortic ring of rats. Their cardiac side effects were explored. The patch-clamp, confocal laser microscopy and the computer-fitting molecular docking experiments were employed to investigate the possible working mechanisms of these calcium antagonists. RESULTS The novel calcium antagonists, X1, X2 and X3 showed stronger vasodilation effect and less cardiac side effect than that of classical calcium antagonists. They blocked L-type calcium channels with an potent effect order of X1 > X2 > X3. Consistently, X1, X2 and X3 interacted with different regions of Ca2+-CaM-CaV1.2 with an affinity order of X1 > X2 > X3. CONCLUSIONS The new halopedidol derivatives X1, X2 and X3 are novel calcium antagonists with stronger vasodilation effect and less cardiac side effect. They could have wide clinical application. PMID:26544729

  15. Room temperature Ultraviolet B emission from InAlGaN films synthesized by plasma-assisted molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Kong, W., E-mail: wei.kong@duke.edu; Jiao, W. Y.; Kim, T. H.; Brown, A. S. [Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 (United States); Roberts, A. T. [Charles Bowden Laboratory, Army Aviation and Missile RD& E Center, Redstone Arsenal, Alabama 35898 (United States); Fournelle, J. [Department of Geoscience, University of Wisconsin, Madison, Wisconsin 53706 (United States); Losurdo, M. [CNR-NANOTEC, Istituto di Nanotecnologia, via Orabona, 4-70126 Bari (Italy); Everitt, H. O. [Charles Bowden Laboratory, Army Aviation and Missile RD& E Center, Redstone Arsenal, Alabama 35898 (United States); Department of Physics, Duke University, Durham, North Carolina 27708 (United States)

    2015-09-28

    Thin films of the wide bandgap quaternary semiconductor In{sub x}Al{sub y}Ga{sub (1−x−y)}N with low In (x = 0.01–0.05) and high Al composition (y = 0.40–0.49) were synthesized on GaN templates by plasma-assisted molecular beam epitaxy. High-resolution X-ray diffraction was used to correlate the strain accommodation of the films to composition. Room temperature ultraviolet B (280 nm–320 nm) photoluminescence intensity increased with increasing In composition, while the Stokes shift remained relatively constant. The data suggest a competition between radiative and non-radiative recombination occurs for carriers, respectively, localized at centers produced by In incorporation and at dislocations produced by strain relaxation.

  16. Characterization of Newly Synthesized ZrFe2O5 Nanomaterial and Investigations of Its Tremendous Photocatalytic Properties under Visible Light Irradiation

    Directory of Open Access Journals (Sweden)

    Shaukat Ali Shahid

    2013-01-01

    Full Text Available High functional ZrFe2O5 nanoparticles were synthesized using coprecipitation technique. The chemical composition of nanomaterials was studied by energy-dispersive X-ray (EDX. To observe the morphology, field emission scanning electron microscopy (FE-SEM was used. X-ray diffraction (XRD technique was utilized to appraise the structure of the synthesized material. The photocatalytic behavior of ZrFe2O5 nano-particles was investigated by measuring the degradation rate of toluidine blue O (TBO dye in aqueous solution in the presence of ZrFe2O5 nano-particles under visible light irradiation. A steady decrease in absorption peak under visible light irradiation was observed by increasing exposure time. The degradation efficiency was observed as 92% after 140 min of exposure to visible light. Besides, ZrFe2O5 nanophotocatalyst could be recovered and recycled easily. The rate of TBO and total organic carbon (TOC removal under visible light irradiation decreased by only 5% and 10%, respectively, after seven cycles of use, demonstrating the high photostability of the synthesized nano-photocatalyst material.

  17. Late Quaternary evolution of the Rotoaira Basin, northern Tongariro ring plain, New Zealand

    International Nuclear Information System (INIS)

    Lecointre, J.A.; Neall, V.E.; Wallace, R.C.; Elliot, M.B.; Sparks, R.J.

    2004-01-01

    The last 100,000 yr record of volcaniclastic sedimentation in the Rotoaira Basin reflects the critical role played by tectonic and eruptive activity that led to: (1) the catastrophic emplacement of Te Whaiau Formation (60-55 ka); (2) major episodes of effusive activity (c. 30 ka and c. 15 ka); and (3) syn- and post-eruptive lahar aggradation on the shores of Lake Rotoaira. Stratigraphic unconformities, fluvial and aeolian reworking, and subsequent volcanogenic sedimentation indicate that climate change driven periods of erosion contributed significantly to the evolution of the landscape during the late Quaternary. Waters that accumulated in a newly expanded graben formed Lake Rotoaira. An attempt to core through the sediments on the lake's floor revealed a >6.5 m thick mantling of Taupo ignimbrite, restricting chronostratigraphic sampling to the last 1.85 ka. Lake Rotoaira pollen profiles record: (1) the destruction of the indigenous forest by the Taupo ignimbrite eruption; (2) the following period of vegetation recovery (c. 300 yr); and (3) periods of human occupation of the lakeshores (bracken spores and Pinus pollen) in the younger sediments. Coarse sand generated by the 1995-96 tephra-producing Ruapehu eruptions also contributed to the recent lake sedimentation. (author). 59 refs., 9 figs., 1 tab

  18. Quaternary Geologic Map of the Lake Superior 4° x 6° Quadrangle, United States and Canada

    Data.gov (United States)

    Department of the Interior — The Quaternary Geologic Map of the Lake Superior 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as...

  19. Study on Quaternary ground siting of nuclear power plant, (1)

    International Nuclear Information System (INIS)

    Kokusho, Takaji; Nishi, Koichi; Honsho, Shizumitsu

    1991-01-01

    A seismic stability evaluation method for a nuclear power plant to be located on a Quaternary sandy/gravelly ground is discussed herein in terms of the geological and geotechnical survey, design earthquake motion evaluation and geotechnical seismic stability analyses. The geological and geotechnical exploration tunnel in the rock-foundation siting will be difficult in the Quaternary ground siting. Boring, geophysical surveys and soil samplings will play a major role in this case. The design earthquake input spectrum for this siting is proposed so as to take account the significant effect of longer period motion on the ground stability. Equivalent and non-linear analyses demonstrate the seismic stability of the foundation ground so long as the soil density is high. (author)

  20. Late quaternary faulting along the Death Valley-Furnace Creek fault system, California and Nevada

    International Nuclear Information System (INIS)

    Brogan, G.E.; Kellogg, K.S.; Terhune, C.L.; Slemmons, D.B.

    1991-01-01

    The Death Valley-Furnace Creek fault system, in California and Nevada, has a variety of impressive late Quaternary neotectonic features that record a long history of recurrent earthquake-induced faulting. Although no neotectonic features of unequivocal historical age are known, paleoseismic features from multiple late Quaternary events of surface faulting are well developed throughout the length of the system. Comparison of scarp heights to amount of horizontal offset of stream channels and the relationships of both scarps and channels to the ages of different geomorphic surfaces demonstrate that Quaternary faulting along the northwest-trending Furnace Creek fault zone is predominantly right lateral, whereas that along the north-trending Death Valley fault zone is predominantly normal. These observations are compatible with tectonic models of Death Valley as a northwest- trending pull-apart basin

  1. Radiocarbon dating for the Quaternary scientist

    International Nuclear Information System (INIS)

    Pilcher, J.R.

    1991-01-01

    The accuracy of many conventional and accelerator mass spectrometry (AMS) radiocarbon dates is not adequate for the sort of questions now being asked in Quaternary studies. The need for, and effects of, radiocarbon calibration are discussed and guide-lines offered for the selection of a laboratory. High precision laboratories and the use of wiggle matching will go a long way to answering the critical questions of rates of change and durations of events in the Holocene. (Author)

  2. Newly Synthesized Water Soluble Cholinium-Purpurin Photosensitizers and Their Stabilized Gold Nanoparticles as Promising Anticancer Agents

    Directory of Open Access Journals (Sweden)

    Young Key Shim

    2008-05-01

    Full Text Available For possible future use in Photodynamic Therapy (PDT and/or Photothermal Therapy (PTT of cancer and screening of cancer cells a new type of ionic liquid photosensitizer –Cholinium-Purpurin-18 (Chol-Pu-18 – was synthesized and small gold (Au nanoparticles, stabilized by this photosensitizer were prepared without adding any particular reducing agents and CTAB. UV-Vis spectroscopy and Transmission Electron Microscopy (TEM were used for characterization of the nanoparticles and FAB-MS and NMR of the ionic liquid choline hydroxide, purpurin carboxylate and their ionic liquid type of photosensitizer were obtained.

  3. Late Quaternary sea level and environmental changes from relic ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Keywords. Late Quaternary sea level; western margin of India; subsidence; uplift; depositional environment. ...... sea level rise by about 80m (between 12,000 and. 7,000 yr BP) or, .... from the Florida Keys; Palaentology 28 189–206. Carballo ...

  4. Map showing thickness of saturated Quaternary deposits, Sugar House quadrangle, Salt Lake County, Utah, February 1972

    Science.gov (United States)

    Mower, R.W.

    1973-01-01

    Saturated Quaternary deposits in the Sugar Horse quadrangle supply significant quantities of water to wells from which water is withdrawn for domestic, municipal, industrial, and irrigation uses. The deposits consist of clay, silt, sand, and gravel; individual beds range from a few inches to several tens of feet thick. The principal aquifer, which is almost completely within the Quaternary deposits, supplied about 4 percent, or 9,000 acre-feet, of the municipal and industrial water used annually in Salt Lake County during 1964-68.As a general rule, more water is stored and more water will be yielded to a well where aquifers are thicker. This map can be used as a general guide to those areas where greatest amounts of water are stored in the aquifer, and where yields to wells may be greater. Local variations in the ability of saturated deposits to transmit water can alter the general relationship between aquifer thickness and yield of wells.The thickness of saturated Quaternary deposits within the area of the Sugar Horse quadrangle ranges from zero to about 650 feet, as shown on the map. The thickest section of these deposits is near the southwestern corner of the quadrangle, and the thinnest section is along the mountain front adjacent to the approximate eastern limit of saturated Quaternary deposits.The thickness of saturated Quaternary deposits shown on this map is based on drillers’ logs for 55 deep wells (which show the thickness of the Quaternary deposits) and on water-level measurements made in February 1972 in wells in unconfined shallow aquifers.Reports in the following list of selected references contain other information about the saturated Quaternary deposits in this and adjacent parts of Jordan Valley, Utah. The basic-data reports and releases contain well logs, water-level measurements, and other types of basic ground-water data. The interpretive repots contain discussions of the occurrence of ground water, tests to determine hydraulic properties of

  5. Isotopic and chemical investigations of quaternary aquifer in sinai peninsula

    International Nuclear Information System (INIS)

    Sadek, M.A.; Ahmed, M.A.; Awad, M.A.

    2001-01-01

    The present study has been conducted to investigate the renewal activity and mineralization potential of the quaternary aquifer in Sinai peninsula using environmental isotopes and hydrochemistry. The quaternary aquifer is vital for development processes as it has a wide extension and shallow water table. The total dissolved salts vary greatly from one location to another and range widely between 510-7060 mg/1, reflecting all categories from fresh to saline water. The change in salinity all over Sinai can be attributed to variations in the rate of evaporation. Leaching and dissolution of terrestrial salts during floods as well as the effects of sea spray and saline water intrusion. The main sources of groundwater recharge are the infiltration of Local precipitation and surface runoff as well as lateral flow through hydraulic connection with fractured aquifers. Snow melt also contributes to aquifer recharge in some areas in the central part of southern Sinai. The environmental stable isotopic contents of the ground water in the quaternary aquifer in Sinai reflect the isotopic composition of rain water from continental and east Mediterranean precipitation and monsonal air mass which comes from Indian ocean as well as the seepage of partly evaporated floodwater. The southern samples are more suitable for drinking and irrigation purposes due to its lower salinity and sodium hazard

  6. Ion-pair hollow-fiber liquid-phase microextraction of the quaternary ammonium surfactant dicocodimethylammonium chloride.

    Science.gov (United States)

    Hultgren, Sofie; Larsson, Niklas; Nilsson, Bo F; Jönsson, Jan Ake

    2009-02-01

    A two-phase hollow-fiber (HF) liquid-phase microextraction (LPME) method was developed for determination of a quaternary ammonium compound surfactant, dicocodimethylammonium chloride, in aqueous samples. The porous HF was fixed on a metal rod support and was impregnated with approximately 6.6 microL of organic extractant, which was immobilized in the HF pores. Surfactant extraction was facilitated by addition of carboxylic acid to the sample forming neutral ion pairs with the quaternary ammonium compound. After extraction, the analyte was transferred from the organic extractant in the fiber pores by dissolving the 1-octanol into 100 microL methanol. The methanol extract was analyzed by liquid chromatography-mass spectrometry. The method was optimized (with optimized parameters in brackets) with regard to type of organic extractant (1-octanol), fiber length (2 cm), choice and concentration of anionic carrier (600 microg L(-1) octanoate), procedure of transfer to methanol (15-min sonication), sample volume (250 mL), extraction time (17 h), pH (10), and ionic strength (50 mM carbonate). Aspects influencing repeatability in LPME of (quaternary ammonium) surfactants are discussed. The enrichment factor achieved in 250-mL carbonate buffer was around 400. Due to matrix effects, the enrichment factors achieved when industrial process water was analyzed were 120 or about 30% of that in carbonate buffer. Detection limits of 0.3 microg L(-1) in carbonate buffer and 0.9 microg L(-1) in industrial process water were obtained. If the studied compound is seen as a model substance representing quaternary dialkylated dimethylated ammonium surfactants in general, the developed method may be applied to other quaternary ammonium surfactants.

  7. Quaternary ammonium as vector of radioisotopes toward cartilage proteoglycans: in vivo imaging and monitoring of chondrosarcoma

    International Nuclear Information System (INIS)

    Peyrode, C.; Weber, V.; Vidal, A.; Auzeloux, P.; Besse, S.; Chezal, J.M.; Miot-Noirault, E.; Dauplat, M.M.; Gouin, F.; Redini, F.

    2013-01-01

    The full text of the publication follows. AIM: Our strategy consists in using the quaternary ammonium function, that exhibits a high affinity for proteoglycans, as a selective carrier to cartilage of (i) drugs for improving the selectivity or (ii) radioisotopes for imaging and evaluating response to treatment. For diagnosis, a radiotracer radiolabeled with 99m Tc ( 99m Tc-NTP 15-5) was selected and for therapeutic application, a quaternary ammonium derivative of melphalan (Mel-AQ) was synthesized. This study demonstrates the interest of this strategy for the diagnosis and treatment of chondrosarcoma. Methods: 99m Tc-NTP 15-5 imaging was performed at regular intervals in rats bearing ortho-topic swarm chondrosarcoma, controls or treated (Mel-AQ: three intravenous doses of 10 mg/kg). 99m Tc-HMDP imaging (the only radiotracer available for nuclear medicine diagnosis of chondrosarcoma) was also performed. Results: All rats exhibited a significant tumoral uptake of 99m Tc-NTP 15-5 at very early stage of pathology while no palpable nor measurable tumour could be assessed. Furthermore, tumoral uptake increased as pathology progressed over time. When animals were treated with Mel-AQ, a significant tumor growth inhibition was observed with 99m Tc-NTP 15-5 tumoral uptake being significantly decreased as compared to controls. 99m Tc-HMDP bone scans were negative during the whole study. Conclusion: These experimental results underline (i) the potential of the proteoglycan targeting strategy for the early and specific diagnosis imaging of chondrosarcoma and its response to therapy and (ii) the efficiency of the targeted anti-tumoral therapy. In future, we could plan to substitute technetium atom for copper atom for radionuclide therapy application. Grants: INCa, CPER, Ligue contre le cancer, FRI/OSEO. (authors)

  8. Study of ternary and quaternary spontaneous fission of 252Cf with the NESSI detector

    International Nuclear Information System (INIS)

    Tishchenko, V.G.; Jahnke, U.; Herbach, C.M.; Hilscher, D.

    2002-11-01

    Ternary and quaternary spontaneous decay of 252 Cf was studied with the NESSI detector, a combination of two 4π detectors for charged particles, neutrons and γ-rays. The applied method of particle identification by measuring the energies and relative time-of-flights of the decay products is shown to be very effective for the study of rare decay modes. The energy and angular distributions of the decay products, the associated neutron multiplicities, the total energy of the prompt γ-radiation as well as correlations between the various observables were measured for the first time in a single full-scale experiment. The characteristics of ternary fission known from previous investigations are confirmed in the frame of a methodically independent experiment. Preliminary estimates of the quaternary fission yield are presented. An attempt is made to determine the mechanism of quaternary fission. (orig.)

  9. Towards dating Quaternary sediments using the quartz Violet Stimulated Luminescence (VSL) signal

    DEFF Research Database (Denmark)

    Ankjærgaard, C.; Jain, Mayank; Wallinga, J.

    2013-01-01

    Quaternary sediments using the violet (402 nm) stimulated luminescence (VSL) signal of quartz.We develop and test a new post-blue VSL single aliquot regenerative dose dating protocol, and demonstrate that the VSL signal originates from a deep trap at about 1.9 eV with a thermal lifetime of 1011 years at 10......Quartz optically stimulated luminescence (OSL) dating is widely used to determine the time of deposition and burial of Late Quaternary sediments. Application of the method is usually limited to the past 150,000 years due to early saturation of the OSL signal. Here we explore the potential to date...

  10. Synthesis of quaternary aryl phosphonium salts: photoredox-mediated phosphine arylation.

    Science.gov (United States)

    Fearnley, A F; An, J; Jackson, M; Lindovska, P; Denton, R M

    2016-04-11

    We report a synthesis method for the construction of quaternary aryl phoshonium salts at ambient temperature. The regiospecific reaction involves the coupling of phosphines with aryl radicals derived from diaryliodonium salts under photoredox conditions.

  11. Origin, Extent, and Thickness of Quaternary Geologic Units in the Willamette Valley, Oregon

    Science.gov (United States)

    O'Connor, Jim E.; Sarna-Wojcicki, Andrei M.; Wozniak, Karl C.; Polette, Danial J.; Fleck, Robert J.

    2001-01-01

    Stratigraphic and chronologic information collected for Quaternary deposits in the Willamette Valley, Oregon, provides a revised stratigraphic framework that serves as a basis for a 1:250,000-scale map, as well as for thickness estimates of widespread Quaternary geologic units. We have mapped 11 separate Quaternary units that are differentiated on the basis of stratigraphic, topographic, pedogenic, and hydrogeologic properties. In summation, these units reflect four distinct episodes in the Quaternary geologic development of the Willamette Valley: 1) Fluvial sands and gravels that underlie terraces flanking lowland margins and tributary valleys were probably deposited between 2.5 and 0.5 million years ago. They are the oldest widespread surficial Quaternary deposits in the valley. Their present positions and preservation are undoubtedly due to postdepositional tectonic deformation - either by direct tectonic uplift of valley margins, or by regional tectonic controls on local base level. 2) Tertiary and Quaternary excavation or tectonic lowering of the Willamette Valley accommodated as much as 500 m (meters) of lacustrine and fluvial fill. Beneath the lowland floor, much of the upper 10 to 50 m of fill is Quaternary sand and gravel deposited by braided channel systems in subhorizontal sheets 2 to 10 m thick. These deposits grade to gravel fans 40 to 100 m thick where major Cascade Range rivers enter the valley and are traced farther upstream as much thinner valley trains of coarse gravel. The sand and gravel deposits have ages that range from greater than 420,000 to about 12,000 years old. A widely distributed layer of sand and gravel deposited at about 12 ka (kiloannum, thousands of years before the present) is looser and probably more permeable than older sand and gravel. Stratigraphic exposures and drillers' logs indicate that this late Pleistocene unit is mostly between 5 and 20 m thick where it has not been subsequently eroded by the Willamette River and its

  12. Quaternary dating methods

    International Nuclear Information System (INIS)

    Mahaney, W.C.

    1984-01-01

    The papers in this book cover absolute, relative and multiple dating methods, and have been written by specialists from a number of different earth sciences disciplines - their common interest being the dating of geological materials within the Quaternary. Papers on absolute dating methods discuss radiocarbon, uranium-series, potassium argon, 40 Ar/ 39 Ar, paleomagnetic, obsidian hydration, thermoluminescence, amino acid racemization, tree rings, and lichenometric techniques. Those on relative dating include discussions on various geomorphic relative age indicators such as drainage density changes, hypsometric integrals, bifurcation ratios, stream junction angles, spur morphology, hillslope geometry, and till sheet characteristics. The papers on multiple dating cite examples from the Rocky Mountains, Australia, Lake Agassiz Basin, and the Southern Andes. Also included is the panel discussion which reviews and assesses the information presented, and a field trip guide which discusses the sequences of Wisconian tills and interlayered lacustrine and fluvial sediments. (orig.)

  13. Thermoelectric properties of quaternary (Bi,Sb)2(Te,Se)3 compound

    International Nuclear Information System (INIS)

    Lu, Pengfei; Li, Yiluan; Wu, Chengjie; Yu, Zhongyuan; Cao, Huawei; Zhang, Xianlong; Cai, Ningning; Zhong, Xuxia; Wang, Shumin

    2014-01-01

    Highlights: • Sb and Se spin–orbit coupling play a key role in the band structure. • Substituted Bi/Sb and Te/Se have a limited impact on the transport coefficients. • n-Type doping will be preferred for quaternary (Bi,Sb) 2 (Te,Se) 3 compound. -- Abstract: The quaternary (Bi,Sb) 2 (Te,Se) 3 compounds are investigated using first-principles study and Boltzmann transport theory. The energy band structure and density of states are studied in detail. The electronic transport coefficients are then calculated as a function of chemical potential. The figure of merit ZT is obtained assuming a constant relaxation time and an averaged thermal conductivity. Our theoretical result agrees well with previous experimental data

  14. All-optical conversion scheme: Binary to quaternary and quaternary to binary number

    Science.gov (United States)

    Chattopadhyay, Tanay; Roy, Jitendra Nath

    2009-04-01

    To achieve the inherent parallelism in optics a suitable number system and efficient encoding/decoding scheme for handling the data are very much essential. Binary number is accepted as the best representing number system in almost all types of existing electronic computers. But, binary number (0 and 1) is insufficient in respect to the demand of the coming generation. Multi-valued logic (with radix >2) can be viewed as an alternative approach to solve many problems in transmission, storage and processing of large amount of information in digital signal processing. Here, in this paper all-optical scheme for the conversion of binary to quaternary number and vice versa have been proposed and described. Simulation has also been done. In this all-optical scheme the numbers are represented by different discrete polarized state of light.

  15. 13C NMR and XPS characterization of anion adsorbent with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse

    International Nuclear Information System (INIS)

    Cao, Wei; Wang, Zhenqian; Zeng, Qingling; Shen, Chunhua

    2016-01-01

    Highlights: • 13 C NMR and XPS were successfully used to characterize quaternary ammonium groups in the surface of crop straw based anion adsorbents. • The results obtained from different kinds of crop straw material clearly confirmed the presence of quaternary ammonium groups. • The composition of C-groups and N-groups also were determined by curving fitting of high-resolution XPS C1 and N1 spectra. - Abstract: Despite amino groups modified crop straw has been intensively studied as new and low-cost adsorbent for removal of anionic species from water, there is still a lack of clear characterization for amino groups, especially quaternary ammonium groups in the surface of crop straw. In this study, we used 13 C NMR and XPS technologies to characterize adsorbents with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse. 13 C NMR spectra clearly showed the presence of quaternary ammonium groups in lignocelluloses structure of modified crop straw. The increase of nitrogen observed in XPS survey spectra also indicated the existence of quaternary ammonium group in the surface of the adsorbents. The curve fitting of high-resolution XPS N1s and C1s spectra were conducted to probe the composition of nitrogen and carbon contained groups, respectively. The results showed the proportion of quaternary ammonium group significantly increased in the prepared adsorbent’s surface that was dominated by methyl/methylene, hydroxyl, quaternary ammonium, ether and carbonyl groups. This study proved that 13 C NMR and XPS could be successfully utilized for characterization of quaternary ammonium modified crop straw adsorbents.

  16. Combined spectroscopic, DFT, TD-DFT and MD study of newly synthesized thiourea derivative

    Science.gov (United States)

    Menon, Vidya V.; Sheena Mary, Y.; Shyma Mary, Y.; Panicker, C. Yohannan; Bielenica, Anna; Armaković, Stevan; Armaković, Sanja J.; Van Alsenoy, Christian

    2018-03-01

    A novel thiourea derivative, 1-(3-bromophenyl)-3-[3-(trifluoromethyl)phenyl]thiourea (ANF-22) is synthesized and characterized by FTIR, FT-Raman and NMR spectroscopy experimentally and theoretically. A detailed conformational analysis of the title molecule has been conducted in order to locate the lowest energy geometry, which was further subjected to the detailed investigation of spectroscopic, reactive, degradation and docking studies by density functional theory (DFT) calculations and molecular dynamics (MD) simulations. Time dependent DFT (TD-DFT) calculations have been used also in order to simulate UV spectra and investigate charge transfer within molecule. Natural bond orbital analysis has been performed analyzing the charge delocalization and using HOMO and LUMO energies the electronic properties are analyzed. Molecular electrostatic potential map is used for the quantitative measurement of active sites in the molecule. In order to determine the locations possibly prone to electrophilic attacks we have calculated average local ionization energies and mapped them to the electron density surface. Further insight into the local reactivity properties have been obtained by calculation of Fukui functions, also mapped to the electron density surface. Possible degradation properties by the autoxidation mechanism have been assessed by calculations of bond dissociation energies for hydrogen abstraction. Atoms of title molecule with significant interactions with water molecules have been determined by calculations of radial distribution functions. The title compound can be a lead compound for developing new analgesic drug.

  17. High order quaternary arrangement confers increased structural stability to Brucella Spp. lumazine synthase

    Energy Technology Data Exchange (ETDEWEB)

    Zylberman, V.; Craig, P.O.; Klinke, S.; Cauerhff, A.; Goldbaum, F.A. [Instituto Leloir, Buenos Aires (Argentina); Braden, B.C. [Bowie State Univ., Maryland (United States)

    2004-07-01

    The penultimate step in the pathway of riboflavin biosynthesis is catalyzed by the enzyme lumazine synthase (LS). One of the most distinctive characteristics of this enzyme is the structural quaternary divergence found in different species. The protein exists as pentameric and icosahedral forms, built from practically the same structural monomeric unit. The pentameric structure is formed by five 18 kDa monomers, each extensively contacting neighboring monomers. The icosahedral structure consists of 60 LS monomers arranged as twelve pentamers giving rise to a capsid exhibiting icosahedral 532 symmetry. In all lumazine synthases studied, the topologically equivalent active sites are located at the interfaces between adjacent subunits in the pentameric modules. The Brucella spp. lumazine synthase (BLS) sequence clearly diverges from pentameric and icosahedral enzymes. This unusual divergence prompted to further investigate on its quaternary arrangement. In the present work, we demonstrate by means of solution Light Scattering and X-ray structural analyses that BLS assembles as a very stable dimer of pentamers representing a third category of quaternary assembly for lumazine synthases. We also describe by spectroscopic studies the thermodynamic stability of this oligomeric protein, and postulate a mechanism for dissociation/unfolding of this macromolecular assembly. The higher molecular order of BLS increases its stability 20 deg C compared to pentameric lumazine synthases. The decameric arrangement described in this work highlights the importance of quaternary interactions in the stabilization of proteins. (author)

  18. High order quaternary arrangement confers increased structural stability to Brucella Spp. lumazine synthase

    International Nuclear Information System (INIS)

    Zylberman, V.; Craig, P.O.; Klinke, S.; Cauerhff, A.; Goldbaum, F.A.; Braden, B.C.

    2004-01-01

    The penultimate step in the pathway of riboflavin biosynthesis is catalyzed by the enzyme lumazine synthase (LS). One of the most distinctive characteristics of this enzyme is the structural quaternary divergence found in different species. The protein exists as pentameric and icosahedral forms, built from practically the same structural monomeric unit. The pentameric structure is formed by five 18 kDa monomers, each extensively contacting neighboring monomers. The icosahedral structure consists of 60 LS monomers arranged as twelve pentamers giving rise to a capsid exhibiting icosahedral 532 symmetry. In all lumazine synthases studied, the topologically equivalent active sites are located at the interfaces between adjacent subunits in the pentameric modules. The Brucella spp. lumazine synthase (BLS) sequence clearly diverges from pentameric and icosahedral enzymes. This unusual divergence prompted to further investigate on its quaternary arrangement. In the present work, we demonstrate by means of solution Light Scattering and X-ray structural analyses that BLS assembles as a very stable dimer of pentamers representing a third category of quaternary assembly for lumazine synthases. We also describe by spectroscopic studies the thermodynamic stability of this oligomeric protein, and postulate a mechanism for dissociation/unfolding of this macromolecular assembly. The higher molecular order of BLS increases its stability 20 deg C compared to pentameric lumazine synthases. The decameric arrangement described in this work highlights the importance of quaternary interactions in the stabilization of proteins. (author)

  19. 13C NMR and XPS characterization of anion adsorbent with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse

    Science.gov (United States)

    Cao, Wei; Wang, Zhenqian; Zeng, Qingling; Shen, Chunhua

    2016-12-01

    Despite amino groups modified crop straw has been intensively studied as new and low-cost adsorbent for removal of anionic species from water, there is still a lack of clear characterization for amino groups, especially quaternary ammonium groups in the surface of crop straw. In this study, we used 13C NMR and XPS technologies to characterize adsorbents with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse. 13C NMR spectra clearly showed the presence of quaternary ammonium groups in lignocelluloses structure of modified crop straw. The increase of nitrogen observed in XPS survey spectra also indicated the existence of quaternary ammonium group in the surface of the adsorbents. The curve fitting of high-resolution XPS N1s and C1s spectra were conducted to probe the composition of nitrogen and carbon contained groups, respectively. The results showed the proportion of quaternary ammonium group significantly increased in the prepared adsorbent's surface that was dominated by methyl/methylene, hydroxyl, quaternary ammonium, ether and carbonyl groups. This study proved that 13C NMR and XPS could be successfully utilized for characterization of quaternary ammonium modified crop straw adsorbents.

  20. Mechanical and bio-corrosion properties of quaternary Mg–Ca–Mn–Zn alloys compared with binary Mg–Ca alloys

    International Nuclear Information System (INIS)

    Bakhsheshi-Rad, H.R.; Idris, M.H.; Abdul-Kadir, M.R.; Ourdjini, A.; Medraj, M.; Daroonparvar, M.; Hamzah, E.

    2014-01-01

    Highlights: • Quaternary alloy show better mechanical and corrosion properties than binary alloy. • Mg–2Ca–0.5Mn–2Zn alloy showed suitable mechanical properties for bone application. • The improved corrosion resistance with addition of Mn and Zn into the Mg–Ca alloy. • Formation of protective surface film Mn-containing magnesium on quaternary alloy. • Secondary phases have strong effect on micro-galvanic corrosion of Mg alloys. - Abstract: Binary Mg–xCa alloys and the quaternary Mg–Ca–Mn–xZn were studied to investigate their bio-corrosion and mechanical properties. The surface morphology of specimens was characterized by X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results of mechanical properties show that the yield strength (YS), ultimate tensile strength (UTS) and elongation of quaternary alloy increased significantly with the addition of zinc (Zn) up to 4 wt.%. However, further addition of Zn content beyond 4 wt.% did not improve yield strength and ultimate tensile strength. In contrast, increasing calcium (Ca) content has a deleterious effect on binary Mg–Ca alloys. Compression tests of the magnesium (Mg) alloys revealed that the compression strength of quaternary alloy was higher than that of binary alloy. However, binary Mg–Ca alloy showed higher reduction in compression strength after immersion in simulated body fluid. The bio-corrosion behaviour of the binary and quaternary Mg alloys were investigated using immersion tests and electrochemical tests. Electrochemical tests shows that the corrosion potential (E corr ) of binary Mg–2Ca significantly shifted toward nobeler direction from −1996.8 to −1616.6 mV SCE with the addition of 0.5 wt.% manganese (Mn) and 2 wt.% Zn content. However, further addition of Zn to 7 wt.% into quaternary alloy has the reverse effect. Immersion tests show that the quaternary

  1. Uranium-series dating of Quaternary deposits

    International Nuclear Information System (INIS)

    Schwarcz, H.; Gascoyne, M.

    1984-01-01

    In view of the interest in the problem of time scales in geomorphology it is fortunate that there exists a number of geochronometers applicable to the measurement of the age of such young deposits. This paper is specifically devoted to those which arise from the disequilibrium between the daughter isotopes of U-238 and U-235, and their respective parents. The authors describe applications to Quaternary continental deposits that can give information about climatic change (travertine, lacrustine limestones, pedogenic carbonates, detrinal sediments, volcanic rocks). (Auth.)

  2. Quaternary climate changes explain diversity among reptiles and amphibians

    DEFF Research Database (Denmark)

    Bastos Araujo, Miguel; Nogués-Bravo, David; Diniz-Filho, Alexandre F.

    2008-01-01

    debated without reaching consensus. Here, we test the proposition that European species richness of reptiles and amphibians is driven by climate changes in the Quaternary. We find that climate stability between the Last Glacial Maximum (LGM) and the present day is a better predictor of species richness...

  3. The Heidelberg Basin Drilling Project - Sedimentology and Stratigraphy of the Quaternary succession

    Science.gov (United States)

    Ellwanger, Dietrich; Gabriel, Gerald; Hahne, Jürgen; Hoselmann, Christian; Menzies, John; Simon, Theo; Weidenfeller, Michael; Wielandt-Schuster, Ulrike

    2010-05-01

    Within the context of the Heidelberg Basin Drilling Project (Gabriel et al. 2008), a detailed sediment succession is presented here based upon deep drillings taken at Heidelberg UniNord and Mannheim Käfertal. Sediment structures, and micromorphological and pollen analyses were conducted and used to reconsider some of the climate transitions within the lower Pleistocene. A new and novel scenario is postulated regarding the preservation of Quaternary sediment packages within the Cenozoic Graben environment of the Heidelberg basin. The palynological evidence comprises the periods of warm climate of the Holsteinian (mainly Abies (fir), some Fagus (beech), Pterocarya & Azolla); the Cromerian (Pinus-Picea-QM (pine-spruce-QM)); the Bavelian (Abies, Tsuga (hemlock fir), QM & phases of increased NAP including Pinus); the Waalian (Abies, Tsuga, QM); and the Tiglian (Fagus & early Pleistocene taxa especially Sciadopytis, downward increasing Tertiary taxa). The sediment package was studied both macroscopically and microscopically. Both techniques provide evidence of fluvial, lacustrine and mass movement sedimentary processes. Some include evidence of periglacial processes (silt droplets within fine grained sands indicative of frozen ground conditions). The periglacial structures are often, not always, accompanied by pollen spectra dominated by pine and NAP. E.g. the Tiglian part of the succession shows periglacial sediment structures at its base and top but not in its middle sections. I.e. it appears not as a series of warm and cold phases but rather as a constant warm period with warm-cold-alternations at its bottom and top. All results illustrate sediment preservation in the Heidelberg basin almost throughout the Quaternary. This may be due to tectonic subsidence, but also to compaction by sediment loading of underlying fine sediments (Oligocene to Quaternary) leading to incomplete but virtually continuous sediment preservation (Tanner et al. 2009). References Gabriel, G

  4. QUATERNARY HISTORY OF CEDRUS IN SOUTHERN EUROPE

    Directory of Open Access Journals (Sweden)

    D. Magri

    2012-05-01

    Full Text Available A database of 68 pollen records of Pleistocene age was compiled from the western Mediterranean regions, with the aim of reconstructing the history of Cedrus in south Europe during the last 2 Ma. Marine pollen records from the Alboran Sea suggest that Cedrus was present in Morocco throughout the Quaternary, while it was absent from the Iberian peninsula, except a possible local presence in a coastal site of southern Spain. In France, Cedrus pollen was recorded in Pliocene deposits, but its Quaternary finds are always very sparse and suggest a long distance origin of cedar pollen. Cedrus was widespread in all the Italian sites during the Early Pleistocene, but it is sporadically found in the Middle Pleistocene deposits. Although times and modes of the disappearance of Cedrus from Italy are not known, it appears that the marked climate changes occurred between 0.9 and 0.7 Ma determined its local extinction. A similar trend is found in Greece, where Cedrus may have persisted a little longer than in the Italian Peninsula. On the whole, the history of Cedrus in southern Europe indicates that it is a taxon vulnerable to global climate changes and warns of a future risk of extinction also in the rest of the Mediterranean Basin.

  5. Quaternary magnetic excursions recorded in marine sediments.

    Science.gov (United States)

    Channell, J. E. T.

    2017-12-01

    This year is the golden (50th) anniversary of the first documentation of a magnetic excursion, the Laschamp excursion in volcanics from the Chaine des Puys (Bonhommet and Babkine, 1967). The first recording of an excursion in sediments was from the Blake Outer Ridge (Smith and Foster, 1969). Magnetic excursions are directional aberrations of the geomagnetic field apparently involving short-lived reversal of the main dipole field. They have durations of a few kyrs, and are therefore rarely recorded in sediments with mean sedimentation rates Palma), and 670 ka (Osaka Bay), implying at least 11 excursions in the Brunhes Chron. For the Matuyama Chron, excursions have been recorded in marine sediments at 868 ka (Kamikatsura?), 932 ka (Santa Rosa), 1051 ka (Intra-Jaramillo), 1115 ka (Punaruu), 1255 ka (Bjorn), 1476 ka (Gardar), 1580 ka (Gilsa), and 2737 ka (Porcupine). Excursions coincide with minima in relative paleointensity (RPI) records. Ages are from correlation of excursion records to oxygen isotope records in the same cores, and ice-volume calibration of the oxygen isotope template. The marine sediment record of excursions, combined with independent documentation of excursions in lavas with Ar/Ar age control, is progressively strengthening our knowledge of the excursion inventory in the Quaternary, and enhancing the importance of excursions and RPI in Quaternary stratigraphy.

  6. A multi-disciplinary review of late Quaternary palaeoclimates and environments for Lesotho

    Directory of Open Access Journals (Sweden)

    Jennifer M. Fitchett

    2016-07-01

    Full Text Available Lesotho provides a unique context for palaeoclimatic research. The small country is entirely landlocked by South Africa, yet has considerable variation in topography, climate, and associated vegetation over an approximate east-west transect. The region has been of archaeological interest for over a century, and hosts many Early to Late Stone Age sites with occupation preceding 80 000 years before present. The eastern Lesotho highlands are of interest to periglacial and glacial geomorphologists because of their well-preserved relict landforms and contentious evidence for permafrost and niche glaciation during the late Quaternary. However, continuous proxy records for palaeoenvironmental reconstructions for Lesotho are scarce and hampered by a range of methodological shortfalls. These challenges include uncertain ages, poor sampling resolution, and proxies extracted from archaeological excavations for which there may be bias in selection. Inferences on palaeoclimates are thus based predominantly on archaeological and palaeogeomorphological evidence for discrete periods during the late Quaternary. This review paper presents a more detailed multidisciplinary synthesis of late Quaternary conditions in Lesotho. We simultaneously considered the varying data that contribute to the under-studied palaeoenvironmental record for southern Africa. The collective palaeoenvironmental data for eastern Lesotho were shown to be relatively contradictory, with considerable variations in contemporaneous palaeoclimatic conditions within the study area. We argue that although methodological challenges may contribute to this variation, the marked changes in topography result in contrasting late Quaternary palaeoenvironments. Such environments are characterised by similar contrasting microclimates and niche ecologies as are witnessed in the contemporary landscape. These spatial variations within a relatively small landlocked country are of importance in understanding

  7. Quaternary alluvial stratigraphy and palaeoclimatic reconstruction at the Thar margin

    DEFF Research Database (Denmark)

    Jain, M.; Tandon, S.K.

    2003-01-01

    Quaternary alluvial record at the Thar desert margin has been examined using the exposed succession along Mahudi, Sabarmati river, Western India. Different alluvial facies, their associations and granulometry have been studied for palaeoenvironmental reconstruction. Clay mineral indices smectite/...

  8. Nano-sized quaternary CuGa2In3S8 as an efficient photocatalyst for solar hydrogen production

    KAUST Repository

    Kandiel, Tarek; Anjum, Dalaver H.; Takanabe, Kazuhiro

    2014-01-01

    The synthesis of quaternary metal sulfide (QMS) nanocrystals is challenging because of the difficulty to control their stoichiometry and phase structure. Herein, quaternary CuGa2In3S8 photocatalysts with a primary particle size of ≈4nm

  9. Electron paramagnetic resonance: A new method of quaternary dating

    International Nuclear Information System (INIS)

    Poupeau, G.; Rossi, A.; Teles, M.M.; Danon, J.

    1984-01-01

    Significant progress has occurred in the last years in quaternary geochronology. One of this is the emergence of a new dating approach, the Electron Spin Resonance Method. The aim of this paper is to briefly review the method and discuss some aspects of the work at CBPF. (Author) [pt

  10. Electron paramagnetic resonance: a new method of quaternary dating

    International Nuclear Information System (INIS)

    Poupeau, G.; Rossi, A.; Universidade Federal Rural do Rio de Janeiro; Telles, M.; Danon, J.

    1984-01-01

    Significant progress has occurred in the last years in quaternary geochronology. One of this is the emergence of a new dating approach, the Electron Spin Resonance Method. The aim of this paper is to briefly review the method and discuss some aspects of the work at CBPF. (Author) [pt

  11. Studies on the site of protein and RNA syntheses in poxvirus-infected cells

    Energy Technology Data Exchange (ETDEWEB)

    Sakaue, Y [Osaka Univ. (Japan). Research Inst. for Microbial Diseases

    1974-04-01

    Pulse labelling of short time and the chase of it were conducted to Poxvirus-infected cells using /sup 3/H-uridine and /sup 3/H-leucine with high concentration, and autoradiography (AR) was taken. As the result, protein synthesis, which was in accordance with ''B''-type inclusion, was markedly observed in one-minute labelling at the site of protein synthesis of infected cells. Although the protein synthesis was observed at the peripheral site of ''A''-type inclusion, it was not found within inclusions. However, it was found from the experiment of chase that protein collected markedly within ''B''-type inclusion. They were found that ''B''-type inclusion is the site of Virus DNA synthesis as well as the site of Virus mRNA synthesis, and that it is also absolutely possible for ''B''-type inclusion to synthesize Virus protein. In addition, it was found that ''A''-type inclusion is not the site of synthesis, but newly-synthesized protein.

  12. Studies on the site of protein and RNA syntheses in poxvirus-infected cells

    International Nuclear Information System (INIS)

    Sakaue, Yoshihiro

    1974-01-01

    Pulse labelling of short time and the chase of it were conducted to Poxvirus-infected cells using 3 H-uridine and 3 H-leucine with high concentration, and autoradiography (AR) was taken. As the result, protein synthesis, which was in accordance with ''B''-type inclusion, was markedly observed in one-minute labelling at the site of protein synthesis of infected cells. Although the protein synthesis was observed at the peripheral site of ''A''-type inclusion, it was not found within inclusions. However, it was found from the experiment of chase that protein collected markedly within ''B''-type inclusion. They were found that ''B''-type inclusion is the site of Virus DNA synthesis as well as the site of Virus mRNA synthesis, and that it is also absolutely possible for ''B''-type inclusion to synthesize Virus protein. In addition, it was found that ''A''-type inclusion is not the site of synthesis, but newly-synthesized protein. (Ichikawa, K.)

  13. Characterization of Quaternary and suspected Quaternary faults, Amargosa area, Nevada and California

    International Nuclear Information System (INIS)

    Anderson, R.E.; Crone, A.J.; Machette, M.N.; Bradley, L.A.; Diehl, S.F.

    1995-01-01

    This report presents the results of geologic studies that help define the Quaternary history of selected faults in the region around Yucca Mountain, Nevada. These results are relevant to the seismic-design basis of a potential nuclear waste repository at Yucca Mountain. The relevancy is based, in part, on a need for additional geologic data that became apparent in ongoing studies by S. Pezzopane (written commun., 1995) that resulted in the identification of 51 relevant and potentially relevant (see appendix A for definitions) individual and compound faults and fault zones in the 100-km-radius region around the Yucca Mountain site. These structures were divided into local and regional categories by Pezzopane (1995); this report deals with selected regional structures. In this introduction, the authors outline the scope and strategy of the studies and the tectonic environment of the studied structures

  14. Characterization of Quaternary and suspected Quaternary faults, Amargosa area, Nevada and California

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, R.E.; Crone, A.J.; Machette, M.N.; Bradley, L.A.; Diehl, S.F.

    1995-12-31

    This report presents the results of geologic studies that help define the Quaternary history of selected faults in the region around Yucca Mountain, Nevada. These results are relevant to the seismic-design basis of a potential nuclear waste repository at Yucca Mountain. The relevancy is based, in part, on a need for additional geologic data that became apparent in ongoing studies by S. Pezzopane (written commun., 1995) that resulted in the identification of 51 relevant and potentially relevant (see appendix A for definitions) individual and compound faults and fault zones in the 100-km-radius region around the Yucca Mountain site. These structures were divided into local and regional categories by Pezzopane (1995); this report deals with selected regional structures. In this introduction, the authors outline the scope and strategy of the studies and the tectonic environment of the studied structures.

  15. Peptides derivatized with bicyclic quaternary ammonium ionization tags. Sequencing via tandem mass spectrometry.

    Science.gov (United States)

    Setner, Bartosz; Rudowska, Magdalena; Klem, Ewelina; Cebrat, Marek; Szewczuk, Zbigniew

    2014-10-01

    Improving the sensitivity of detection and fragmentation of peptides to provide reliable sequencing of peptides is an important goal of mass spectrometric analysis. Peptides derivatized by bicyclic quaternary ammonium ionization tags: 1-azabicyclo[2.2.2]octane (ABCO) or 1,4-diazabicyclo[2.2.2]octane (DABCO), are characterized by an increased detection sensitivity in electrospray ionization mass spectrometry (ESI-MS) and longer retention times on the reverse-phase (RP) chromatography columns. The improvement of the detection limit was observed even for peptides dissolved in 10 mM NaCl. Collision-induced dissociation tandem mass spectrometry of quaternary ammonium salts derivatives of peptides showed dominant a- and b-type ions, allowing facile sequencing of peptides. The bicyclic ionization tags are stable in collision-induced dissociation experiments, and the resulted fragmentation pattern is not significantly influenced by either acidic or basic amino acid residues in the peptide sequence. Obtained results indicate the general usefulness of the bicyclic quaternary ammonium ionization tags for ESI-MS/MS sequencing of peptides. Copyright © 2014 John Wiley & Sons, Ltd.

  16. Hydrolysis of cellulose catalyzed by quaternary ammonium perrhenates in 1-allyl-3-methylimidazolium chloride.

    Science.gov (United States)

    Wang, Jingyun; Zhou, Mingdong; Yuan, Yuguo; Zhang, Quan; Fang, Xiangchen; Zang, Shuliang

    2015-12-01

    Quaternary ammonium perrhenates were applied as catalyst to promote the hydrolysis of cellulose in 1-allyl-3-methylimidazolium chloride ([Amim]Cl). The quaternary ammonium perrhenates displayed good catalytic performance for cellulose hydrolysis. Water was also proven to be effective to promote cellulose hydrolysis. Accordingly, 97% of total reduced sugar (TRS) and 42% of glucose yields could be obtained under the condition of using 5mol% of tetramethyl ammonium perrhenate as catalyst, 70μL of water, ca. 0.6mmol of microcrystalline cellulose (MCC) and 2.0g of [Amim]Cl as solvent under microwave irradiation for 30min at 150°C (optimal conditions). The influence of quaternary ammonium cation on the efficiency of cellulose hydrolysis was examined based on different cation structures of perrhenates. The mechanism on perrhenate catalyzed cellulose hydrolysis is also discussed, whereas hydrogen bonding between ReO4 anion and hydroxyl groups of cellulose is assumed to be the key step for depolymerization of cellulose. Copyright © 2015. Published by Elsevier Ltd.

  17. Quaternary oxide halides of group 15 with zinc and cadmium; Quaternaere Oxidhalogenide der Gruppe 15 mit Zink und Cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Rueck, Nadia

    2014-07-30

    The present thesis ''Quaternary oxide halides of group 15 with zinc and cadmium'' deals with the chemical class of oxide halides, which contain d-block element cations and pnicogens. Over the past few years compounds containing pnicogene cations are intensively investigated. The reason for this is the free electron pair of the Pn{sup 3+} cation, which is responsible for some interesting properties. Free electron pairs do not only impact the spatial structure of molecules but also the properties of materials. The object of this work was the synthesis and characterization of compounds containing Pn{sup 3+} cations with free electron pairs. Due to the structure-determining effect of these free electron pairs and in combination with halides it is possible to synthesize compounds with low-dimensional structures like chains and layers. In these compounds the structure is separated into halophilic and chalcophilic sub-structures, which are held together only by weak Van der Waals forces.

  18. UVB-emitting InAlGaN multiple quantum well synthesized using plasma-assisted molecular beam epitaxy

    Directory of Open Access Journals (Sweden)

    W. Kong

    2017-03-01

    Full Text Available A high Al-content (y > 0.4 multi-quantum-well (MQW structure with a quaternary InxAlyGa(1-x-yN active layer was synthesized using plasma-assisted molecular beam epitaxy. The MQW structure exhibits strong carrier confinement and room temperature ultraviolet-B (UVB photoluminescence an order of magnitude stronger than that of a reference InxAlyGa(1-x-yN thin film with comparable composition and thickness. The samples were characterized using spectroscopic ellipsometry, atomic force microscopy, and high-resolution X-ray diffraction. Numerical simulations suggest that the UVB emission efficiency is limited by dislocation-related non-radiative recombination centers in the MQW and at the MQW - buffer interface. Emission efficiency can be significantly improved by reducing the dislocation density from 109cm−2 to 107cm−2 and by optimizing the width and depth of the quantum wells.

  19. Quaternary structure of the lactose transport protein of Streptococcus thermophilus in the detergent-solubilized and membrane-reconstituted state

    NARCIS (Netherlands)

    Friesen, R.H.E.; Poolman, B.; Knol, J.

    2000-01-01

    The quaternary structure of LacS, the lactose transporter of Streptococcus thermophilus, has been determined for the detergent-solubilized and the membrane-reconstituted state of the protein. The quaternary structure of the n-dodecyl-β-D-maltoside-solubilized state was studied using a combination of

  20. Origin of Bermuda's clay-rich Quaternary paleosols and their paleoclimatic significance

    Science.gov (United States)

    Herwitz, S.R.; Muhs, D.R.; Prospero, J.M.; Mahan, S.; Vaughn, B.

    1996-01-01

    Red clayey paleosols that are chiefly the product of aerosolic dust deposition are interbedded in the Quaternary carbonate formations of the Bermuda oceanic island system. These paleosols provide a basis for reconstructing Quaternary atmospheric circulation patterns in the northwestern Atlantic. Geochemical analyses were performed on representative paleosol samples to identify their parent dust source. Fine-grained fractions were analyzed by energy-dispersive X ray fluorescence to determine trace element (Zr, Y, La, Ti, and Nb) concentrations and to derive geochemical signatures based on immobile element ratios. These ratios were compared with geochemical signatures determined for three possible sources of airborne dust: (1) Great Plains loess, (2) Mississippi River Valley loess, and (3) Saharan dust. The Zr/Y and Zr/La ratios provided the clearest distinction between the hypothesized dust sources. The low ratios in the paleosol B horizons most closely resemble Saharan dust in the the two North American loessial source areas could not be clearly detected. Thus Bermuda paleosols have a predominantly Saharan aerosolic dust signature. Saharan dust deposition on Bermuda during successive Quaternary glacial periods is consistent with patterns of general circulation models, which indicate that during glacial maxima the northeast summer trade winds were stronger than at present and reached latitudes higher than 30 ?? N despite lower-than-present sea surface temperatures in the North Atlantic.

  1. Syntheses and anti-microbial evaluation of new quinoline scaffold derived pyrimidine derivatives

    Directory of Open Access Journals (Sweden)

    Shikha S. Dave

    2016-09-01

    Full Text Available A series of diversely substituted chalcones derived from a quinoline scaffold, e.g. (E-3-(2-chloroquinolin-3-yl-1-(2-hydroxyphenyl prop-2-en-1-one and its pyrimidine analogues e.g. 2-[2-amino-6-(2-chloroquinolin-3-yl-5,6-dihydropyrimidin-4-yl]phenols have been prepared by condensation of 2-chloro-3-formyl quinoline with differently substituted 2-hydroxy acetophenones and further treatment with guanidine carbonate. All the newly synthesized compounds have been evaluated for their in vitro growth inhibitory activity against Escherichia coli, Pseudomonas vulgaris, Bacillus subtilis, Staphylococcus aureus, Staphylococcus typhi, Candida albicans, Aspergillus niger and Pseudomonas chrysogenum.

  2. {sup 13}C NMR and XPS characterization of anion adsorbent with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Wei, E-mail: weicao@hqu.edu.cn; Wang, Zhenqian; Zeng, Qingling; Shen, Chunhua

    2016-12-15

    Highlights: • {sup 13}C NMR and XPS were successfully used to characterize quaternary ammonium groups in the surface of crop straw based anion adsorbents. • The results obtained from different kinds of crop straw material clearly confirmed the presence of quaternary ammonium groups. • The composition of C-groups and N-groups also were determined by curving fitting of high-resolution XPS C1 and N1 spectra. - Abstract: Despite amino groups modified crop straw has been intensively studied as new and low-cost adsorbent for removal of anionic species from water, there is still a lack of clear characterization for amino groups, especially quaternary ammonium groups in the surface of crop straw. In this study, we used {sup 13}C NMR and XPS technologies to characterize adsorbents with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse. {sup 13}C NMR spectra clearly showed the presence of quaternary ammonium groups in lignocelluloses structure of modified crop straw. The increase of nitrogen observed in XPS survey spectra also indicated the existence of quaternary ammonium group in the surface of the adsorbents. The curve fitting of high-resolution XPS N1s and C1s spectra were conducted to probe the composition of nitrogen and carbon contained groups, respectively. The results showed the proportion of quaternary ammonium group significantly increased in the prepared adsorbent’s surface that was dominated by methyl/methylene, hydroxyl, quaternary ammonium, ether and carbonyl groups. This study proved that {sup 13}C NMR and XPS could be successfully utilized for characterization of quaternary ammonium modified crop straw adsorbents.

  3. Synthesis of Quaternary Ammonium Salts Based on Diketopyrrolopyrroles Skeletons and Their Applications in Copper Electroplating.

    Science.gov (United States)

    Chen, Biao; Xu, Jie; Wang, Limin; Song, Longfeng; Wu, Shengying

    2017-03-01

    A series of DPP derivatives bearing quaternary ammonium salt centers with different lengths of carbon chains have been designed and synthesized. Their inhibition actions on copper electroplating were first investigated. A total of four diketopyrrolopyrrole (DPP) derivatives showed different inhibition capabilities on copper electroplating. To investigate interactions between metal surface and additives, we used quantum chemical calculations. Static and dynamic surface tension of four DPP derivatives had been measured, and the results showed DPP-10C (1c) with a faster-decreasing rate of dynamic surface tension among the four derivatives, which indicated higher adsorption rate of additive on the cathode surface and gives rise to stronger inhibiting effect of copper electrodeposition. Then, DPP-10C (1c) as the representative additive, was selected for the systematic study of the leveling influence during microvia filling through comprehensive electroplating tests. In addition, field-emission scanning electron microscope images and X-ray diffraction results showed the surface morphology, which indicated that addition of DPP derivative (1c) could lead a fine copper deposit and cause the preferential orientations of copper deposits to change from [220] to [111], which happened in particular at higher concentrations.

  4. Analysis of multiple quaternary ammonium compounds in the brain using tandem capillary column separation and high resolution mass spectrometric detection.

    Science.gov (United States)

    Falasca, Sara; Petruzziello, Filomena; Kretz, Robert; Rainer, Gregor; Zhang, Xiaozhe

    2012-06-08

    Endogenous quaternary ammonium compounds are involved in various physiological processes in the central nervous system. In the present study, eleven quaternary ammonium compounds, including acetylcholine, choline, carnitine, acetylcarnitine and seven other acylcarnitines of low polarity, were analyzed from brain extracts using a two dimension capillary liquid chromatography-Fourier transform mass spectrometry method. To deal with their large difference in hydrophobicities, tandem coupling between reversed phase and hydrophilic interaction chromatography columns was used to separate all the targeted quaternary ammonium compounds. Using high accuracy mass spectrometry in selected ion monitoring mode, all the compounds could be detected from each brain sample with high selectivity. The developed method was applied for the relative quantification of these quaternary ammonium compounds in three different brain regions of tree shrews: prefrontal cortex, striatum, and hippocampus. The comparative analysis showed that quaternary ammonium compounds were differentially distributed across the three brain areas. The analytical method proved to be highly sensitive and reliable for simultaneous determination of all the targeted analytes from brain samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Sensitive electrospray mass spectrometry analysis of one-bead-one-compound peptide libraries labeled by quaternary ammonium salts.

    Science.gov (United States)

    Bąchor, Remigiusz; Cydzik, Marzena; Rudowska, Magdalena; Kluczyk, Alicja; Stefanowicz, Piotr; Szewczuk, Zbigniew

    2012-08-01

    A rapid and straightforward method for high-throughput analysis of single resin beads from one-bead-one-compound combinatorial libraries with high resolution electrospray ionization tandem mass spectrometry (HR ESI-MS/MS) is presented. The application of an efficient method of peptide derivatization by quaternary ammonium salts (QAS) formation increases ionization efficiency and reduces the detection limit, allowing analysis of trace amounts of compounds by ESI-MS. Peptides, synthesized on solid support, contain a new cleavable linker composed of a Peg spacer (9-aza-3,6,12,15-tetraoxa-10-on-heptadecanoic acid), lysine with ɛ-amino group marked by the N,N,N-triethylglycine salt, and methionine, which makes possible the selective cleavage by cyanogen bromide. Even a small portion of peptides derivatized by QAS cleaved from a single resin bead is sufficient for sequencing by HR ESI-MS/MS experiments. The developed strategy was applied to a small training library of α chymotrypsin substrates. The obtained results confirm the applicability of the proposed method in combinatorial chemistry.

  6. Acid resistance of quaternary blended recycled aggregate concrete

    Directory of Open Access Journals (Sweden)

    K Jagannadha Rao

    2018-06-01

    Full Text Available The possibility of reusing the aggregate from demolished structures in fresh concrete, in order to reduce the CO2 impact on the environment [23] and to preserve natural resources, was explored worldwide and it is established that recycled aggregates can be used as a partial replacement of natural aggregates. Due to its potential to be used in eco-friendly structures and shortage of supply of natural aggregates in some parts of the world, there is an increasing interest in using the recycled aggregate. The durability aspects are also of equal concern along with the strength and economy of any material to be used in the construction. Studies reveal that the behaviour of ternary and quaternary blended concretes is superior from durability point of view compared to conventional concrete. Therefore a study is conducted to assess the acid resistance of recycled aggregate based Quaternary Blended Cement Concrete (QBCC of two grades M40 and M60. Fly ash and silica fume are fixed at 20% and 10% respectively from the previous studies while two percentages of Nano silica (2 and 3% were used along with the cement to obtain QBCC. Three percentages of recycled aggregates as partial replacement of conventional aggregate (0%, 50% and 75% were used in this study. Two different acids (HCL and H2SO4 with different concentrations (3 and 5% were used in this study. Acid resistance of QBCC with Recycled Concrete Aggregate (RCA is assessed in terms of visual appearance, weight loss, and compressive strength loss by destructive and non-destructive tests at regular intervals for a period of 56 days. The test results showed marginal weight loss and strength loss in both M40 and M60 grades of concretes. The Ultrasonic Pulse Velocity (UPV results show that the quality of QBCC is good even after being subjected to acid exposure. Keywords: Recycled concrete aggregate (RCA, Quaternary blended cement concrete (QBCC, Acid resistance, Ultrasonic pulse velocity (UPV, Mineral

  7. Late Quaternary climate change shapes island biodiversity.

    Science.gov (United States)

    Weigelt, Patrick; Steinbauer, Manuel Jonas; Cabral, Juliano Sarmento; Kreft, Holger

    2016-04-07

    Island biogeographical models consider islands either as geologically static with biodiversity resulting from ecologically neutral immigration-extinction dynamics, or as geologically dynamic with biodiversity resulting from immigration-speciation-extinction dynamics influenced by changes in island characteristics over millions of years. Present climate and spatial arrangement of islands, however, are rather exceptional compared to most of the Late Quaternary, which is characterized by recurrent cooler and drier glacial periods. These climatic oscillations over short geological timescales strongly affected sea levels and caused massive changes in island area, isolation and connectivity, orders of magnitude faster than the geological processes of island formation, subsidence and erosion considered in island theory. Consequences of these oscillations for present biodiversity remain unassessed. Here we analyse the effects of present and Last Glacial Maximum (LGM) island area, isolation, elevation and climate on key components of angiosperm diversity on islands worldwide. We find that post-LGM changes in island characteristics, especially in area, have left a strong imprint on present diversity of endemic species. Specifically, the number and proportion of endemic species today is significantly higher on islands that were larger during the LGM. Native species richness, in turn, is mostly determined by present island characteristics. We conclude that an appreciation of Late Quaternary environmental change is essential to understand patterns of island endemism and its underlying evolutionary dynamics.

  8. Synthesis and Characterization of Novel Ternary and Quaternary Alkali Metal Thiophosphates

    KAUST Repository

    Alahmary, Fatimah S.

    2014-01-01

    The ongoing development of nonlinear optical (NLO) crystals such as coherent mid-IR sources focuses on various classes of materials such as ternary and quaternary metal chalcophosphates. In case of thiophosphates, the connection between PS4

  9. Study of the influence of pre-activation of vermiculite and concentration of the quaternary ammonium salt in obtaining of organovermiculita

    International Nuclear Information System (INIS)

    Silva, A.L.; Barboza, E.A.; Souza, F.K.A.; Neves, G.A.; Santana, L.N.L.

    2011-01-01

    Organoclays, are derived from the addition of quaternary ammonium salts in aqueous dispersions of natural clays or sodium. The aim of this study was to obtain organoclays from the intercalation of clay mineral vermiculite and quaternary ammonium salt Praepagem WB, thus, was used to study the concentrations of salt activation of Na 2 CO 3 , the cure time of this salt and varying the concentration the quaternary ammonium salt. The X-ray diffraction was used to determine whether there was a change in basal spacing after intercalation process with the quaternary ammonium salt. The process of organophilization of vermiculite, was confirmed by change in clay basal interplanar distance, which was 14.32 Å and after the addition of salt increased to 60.04 Å when activated for 5 days. (author)

  10. A revision of the Pliocene and Quaternary Lutrinae from Europe

    NARCIS (Netherlands)

    Willemsen, G.F.

    1992-01-01

    In this paper, a revision of the Pliocene and Quaternary Lutrinae from Europe is presented. Such a revision, including fossil material, has not been published since the work of Pohle (1919). Three tribes within the Lutrinae are recognized: the Lutrini, the Aonyxini and the Enhydrini. The latter

  11. Human Dispersals Along the African Rift Valley in the Late Quaternary

    Science.gov (United States)

    Tryon, C. A.; Faith, J. T.; Peppe, D. J.

    2014-12-01

    Climate- and tectonic-driven environmental dynamics of the East African Rift System (EARS) during the Quaternary played an important role in the demographic history of early Homo sapiens, including expansions of modern humans across and out of Africa. Human forager population size, geographic range, and behaviors such as hunting strategies and residential mobility likely varied in response to changes in the local and regional environment. Throughout the Quaternary, floral and faunal change was linked at least in part to variations in moisture availability, temperature, and atmospheric CO2, which in addition to uplift and faulting, contributed to the expansion and contraction of a number of large lakes that served as biogeographic barriers to many taxa. This is particularly clear for the Lake Victoria basin, where biogeographic, geological, and paleontological evidence documents repeated expansion and contraction of the ranges of species in response to lake level and vegetation change. Across much of eastern Africa, the topography of the rift facilitated north-south dispersals, the timing of which may have depended in part on the expansion and contraction of the equatorial forest belt. Dispersal potential likely increased during the more arid periods of the late Quaternary, when the roles of lakes and forests as dispersal barriers was reduced and the extent of low net primary productivity dry grasslands increased, the latter requiring large home ranges for human foragers, conditions suitable for range expansions within H. sapiens.

  12. Groundwater and quaternary geological studies of potential peat production areas - useful tool for sustainable peat production

    Energy Technology Data Exchange (ETDEWEB)

    Valpola, S.E.; Paalijaervi, M. (Geological Survey of Finland, Kokkola (Finland)), Email: samu.valpola@gtk.fi, Email: miikka.paalijarvi@gtk.fi

    2009-07-01

    Potential peat production areas in Finland are often situated in vicinity of eskers or other quaternary (glaciofluvial) formations. Frequently these formations are also important groundwater resources and it is essential for sustainable peat production to assure that these resources will not be endangered. The Geological Survey of Finland (GTK) has concluded several quaternary geological studies on potential peat production areas, which are connected to locally important groundwater areas. These studies have been made using mainly ground penetrating radar (GPR) and light drilling equipment. The main objective of these studies has been to establish the local groundwater flow directions and the quality and extent of quaternary deposits. The increasing need of peat production areas has created an evident demand of cost-effective and fast research methods which can be used for providing reliable information for planning of new production areas. (orig.)

  13. Evaluating the Significance of Paleophylogeographic Species Distribution Models in Reconstructing Quaternary Range-Shifts of Nearctic Chelonians

    OpenAIRE

    R?dder, Dennis; Lawing, A. Michelle; Flecks, Morris; Ahmadzadeh, Faraham; Dambach, Johannes; Engler, Jan O.; Habel, Jan Christian; Hartmann, Timo; H?rnes, David; Ihlow, Flora; Schidelko, Kathrin; Stiels, Darius; Polly, P. David

    2013-01-01

    The climatic cycles of the Quaternary, during which global mean annual temperatures have regularly changed by 5-10°C, provide a special opportunity for studying the rate, magnitude, and effects of geographic responses to changing climates. During the Quaternary, high- and mid-latitude species were extirpated from regions that were covered by ice or otherwise became unsuitable, persisting in refugial retreats where the environment was compatible with their tolerances. In this study we combine ...

  14. Quaternary sediment thickness and bedrock topography of the glaciated United States east of the Rocky Mountains

    Science.gov (United States)

    Soller, David R.; Garrity, Christopher P.

    2018-01-26

    Beginning roughly 2.6 million years ago, global climate entered a cooling phase known as the Pleistocene Epoch. As snow in northern latitudes compacted into ice several kilometers thick, it flowed as glaciers southward across the North American continent. These glaciers extended across the northern United States, dramatically altering the landscape they covered. East of the Rocky Mountains, the ice coalesced into continental glaciers (called the Laurentide Ice Sheet) that at times blanketed much of the north-central and northeastern United States. To the west of the Laurentide Ice Sheet, glaciers formed in the mountains of western Canada and the United States and coalesced into the Cordilleran ice sheet; this relatively smaller ice mass extended into the conterminous United States in the northernmost areas of western Montana, Idaho, and Washington. Throughout the Pleistocene, landscape alteration occurred by (1) glacial erosion of the rocks and sediments; (2) redeposition of the eroded earth materials in a form substantially different from their source rocks, in terms of texture and overall character; and (3) disruption of preexisting drainage patterns by the newly deposited sediments. In many cases, pre-glacial drainage systems (including, for example, the Mississippi River) were rerouted because their older drainage courses became blocked with glacial sediment.The continental glaciers advanced and retreated many times across those areas. During each ice advance, or glaciation, erosion and deposition occurred, and the landscape was again altered. Through successive glaciations, the landscape and the bedrock surface gradually came to resemble their present configurations. As continental ice sheets receded and the Pleistocene ended, erosion and deposition of sediment (for example in stream valleys) continued to shape the landscape up to the present day (albeit to a lesser extent than during glaciation). The interval of time since the last recession of the glaciers

  15. Palladium-catalyzed asymmetric alkylation in the synthesis of cyclopentanoid and cycloheptanoid core structures bearing all-carbon quaternary stereocenters

    KAUST Repository

    Hong, Allen Y.

    2011-12-01

    General catalytic asymmetric routes toward cyclopentanoid and cycloheptanoid core structures embedded in numerous natural products have been developed. The central stereoselective transformation in our divergent strategies is the enantioselective decarboxylative alkylation of seven-membered β-ketoesters to form α-quaternary vinylogous esters. Recognition of the unusual reactivity of β-hydroxyketones resulting from the addition of hydride or organometallic reagents enabled divergent access to γ-quaternary acylcyclopentenes through a ring contraction pathway or γ-quaternary cycloheptenones through a carbonyl transposition pathway. Synthetic applications of these compounds were explored through the preparation of mono-, bi-, and tricyclic derivatives that can serve as valuable intermediates for the total synthesis of complex natural products. This work complements our previous work with cyclohexanoid systems.

  16. Studies on ternary and quaternary copper, lithium and silver sulfides with a diamond structure; Untersuchungen an ternaeren und quaternaeren Kupfer-, Lithium-, und Silbersulfiden mit Diamantstruktur

    Energy Technology Data Exchange (ETDEWEB)

    Greil, Sebastian

    2015-04-09

    Within this work new attempts have been done to prepare unknown compounds in the field of quaternary tetrahedral compounds. Therefore it was tried to synthesize compounds of the composition A{sup I}{sub 2}M{sup II}M{sup IV}S{sub 4} with A = Ag, Li, M{sup II} = Fe, Co, Mn, Hg, Cd, Zn, Pb, MIV = Si, Ge, Sn, which are not known in the literature so far. For these compositions the known copper compounds were used as a model. Using this route, the new compounds Ag{sub 2}MnSnS{sub 4}, Ag{sub 2}FeGeS{sub 4}, Li{sub 2}MnSnS{sub 4} and Li{sub 2}FeSnS{sub 4} were synthesized. All of the mentioned compounds except Ag{sub 2}FeGeS{sub 4}, that crystallizes tetragonal, crystallize in the wurtzite-type. The predicted anti-ferromagnetism for Ag{sub 2}MnSnS{sub 4} mentioned in the literature could not be confirmed. Furthermore it was attempted to synthesize new compounds containing titanium, zirconium and hafnium as tetravalent cation that resulted in the compound Cu{sub 2}ZrS{sub 3} which was not known in the literature before. Additionally, the compounds Cu{sub 10}Cd{sub 2}As{sub 4}S{sub 13} and Cu{sub 10}Mn{sub 2}As{sub 4}S{sub 13} were prepared, which could be derived from Cu{sub 12}As{sub 4}S{sub 13}.

  17. Band gap depiction of quaternary FeMnTiAl alloy using Hubbard (U) potential

    Science.gov (United States)

    Bhat, Tahir Mohiuddin; Yousuf, Saleem; Khandy, Shakeel Ahmad; Gupta, Dinesh C.

    2018-05-01

    We have employed self-consistent ab-initio calculations to investigate new quaternary alloy FeMnTiAl by applying Hubbard potential (U). The alloy is found to be stable in ferromagnetic phase with cubic structure. The alloy shows half-metallic (HM) ferromagnet character. The values of minority band gap FeMnTiAl are found to be 0.33 eV respectively. Electronic charge density reveals that both types of bonds covalent as well as ionic are present in the alloy. Thus the new quaternary alloy can be proved as vital contender for spin valves and spin generator devices.

  18. Significant differences in late Quaternary bedrock erosion and transport

    DEFF Research Database (Denmark)

    Andrews, John; Bjørk, Anders Anker; Eberl, Dennis

    2015-01-01

    in 10 cores from the two margins. On the East Greenland Shelf (EGS), late Quaternary samples have an average quartz weight per cent of 6.22.3 versus 12.83.9 from the West Greenland Shelf (WGS), and 12.024.8 versus 1.9 2.3wt% for pyroxene. K-means clustering indicated only 9% of the samples did not fit...

  19. The determination of B and Sr isotopes of quaternary biologic fossils in Yanghuzhuang Yanqing basin and their living environment

    International Nuclear Information System (INIS)

    Xiao Yingkai; Xiao Jun; Zhao Zhiqi; He Maoyong; Li Shizhen

    2007-01-01

    The B and Sr isotopic compositions of early Quaternary biologic fossils in Yanghuzhuang and living bivalves in Weishui river were measured. Comparing with the data of marine foraminifer, the results show a non-marine living environment for these foraminifers lived in early Quaternary in Yanghuzhuang, Yanqing; Basin. (authors)

  20. Sex allocation and functional bias of quaternary and quinary flowers on same inflorescence in the hermaphrodite Ruta graveolens

    Science.gov (United States)

    Tang, Jing-Yu; Ren, Ming-Xun

    2011-09-01

    Intra-inflorescence variation in floral traits is important to understand the pollination function of an inflorescence and the real reproductive outputs of a plant. Ruta graveolens (Rutaceae) produce both quaternary (four petals and eight stamens) and quinary (five petals and ten stamens) flowers on the same cymes, while their pollination roles and the effects on the reproductive success remained unexplored. We experimentally examined the biomass of female versus male organs and pollen viability and stigma receptivity to explore the sex allocation patterns between the flowers. The breeding systems and reproductive outputs through either female function (seed set) or male function (pollen dispersal) were also studied for quinary and quaternary flowers to determine whether there was functional bias. The results showed that R. graveolens was protandrous, with a mixed mating system. Its stamens could slowly move one by one and only dehisce when positioning at the flower center, which could greatly enhance pollen dispersal. The first-opened quinary flower allocated significantly higher resources (dry biomass) in female organs while quaternary flowers allocated more resource in male organs. The quaternary flowers experienced higher pollen limitation in seed production but were more successful in pollen dispersal and the quinary flowers reproduced both through female and male functions. Our data suggested that quinary and quaternary flower on same inflorescence in R. graveolens functioned mainly as the sex role that most resources were allocated, which probably reflect an adaptation for floral phenology and pollination process in this plant.

  1. Formation of low charge state ions of synthetic polymers using quaternary ammonium compounds.

    Science.gov (United States)

    Nasioudis, Andreas; Joyce, William F; van Velde, Jan W; Heeren, Ron M A; van den Brink, Oscar F

    2010-07-01

    Factors such as high polymer dispersity and variation in elemental composition (of copolymers) often complicate the electrospray ionization mass spectrometry (ESI-MS) analysis of synthetic polymers with high molar mass. In the experiments described in this study, quaternary ammonium compounds were observed to facilitate the production of low charge state pseudomolecular ions when added to the spray solution for ESI-MS. This approach was then used for the ESI time-of-flight mass spectrometry (TOF-MS) analysis of synthetic polymers. Hexadecyltrimethylammonium chloride permitted the successful analysis of poly(ethylene glycol) of 2-40 kDa, poly(propylene glycol) and poly(tetramethylene glycol) oligomers. Increasing the quaternary ammonium compounds' concentration results in the production of low charge state pseudomolecular ions. A comparison of structurally different quaternary ammonium compounds showed that the best performance is expected from large molecules with specific charge localization, which leaves the charge available for interactions. The applicability of the method for the MS analysis of other polymeric systems was also studied. In the case of poly(tetramethylene glycol), the method not only shifted the distributions to higher m/z values but also allowed the detection of high molecular weight material that was not observed without addition of the modifier to the spray solution.

  2. Mechanical properties of some binary, ternary and quaternary III-V compound semiconductor alloys

    International Nuclear Information System (INIS)

    Navamathavan, R.; Arivuoli, D.; Attolini, G.; Pelosi, C.; Choi, Chi Kyu

    2007-01-01

    Vicker's microindentation tests have been carried out on InP/InP, GaAs/InP, InGaAs/InP and InGaAsP/InP III-V compound semiconductor alloys. The detailed mechanical properties of these binary, ternary and quaternary epilayers were determined from the indentation experiments. Microindentation studies of (1 1 1) GaAs/InP both A and B faces show that the hardness value increases with load and attains a constant for further increase in load and the microhardness values were found to lie between 3.5 and 4.0 GPa. The microhardness values of InGaAs/InP epilayers with different thickness were found to lie between 3.93 and 4.312 GPa. The microhardness values of InGaAsP/InP with different elemental composition were found to lie between 5.08 and 5.73 GPa. The results show that the hardness of the quaternary alloy drastically increases, the reason may be that the increase in As concentration hardens the lattice when phosphorous concentration is less and hardness decreases when phosphorous is increased. It was interestingly observed that the hardness value increases as we proceed from binary to quaternary III-V compound semiconductor alloys

  3. Fault control on patterns of Quaternary monogenetic vents in the ...

    African Journals Online (AJOL)

    Field and remote sensing data are used to examine the distribution of volcanism and fault geometry in the Ethiopian Rift between Omo-Chew Bahir rift and Tendaho graben during the Quaternary and evaluate their influence on the location and shape of individual vents as well as the development of alignments. The results ...

  4. Diverse range dynamics and dispersal routes of plants on the Tibetan Plateau during the late Quaternary.

    Directory of Open Access Journals (Sweden)

    Haibin Yu

    Full Text Available Phylogeographical studies have suggested that several plant species on the Tibetan Plateau (TP underwent recolonization during the Quaternary and may have had distinct range dynamics in response to the last glacial. To further test this hypothesis and locate the possible historical dispersal routes, we selected 20 plant species from different parts of the TP and modeled their geographical distributions over four time periods using species distribution models (SDMs. Furthermore, we applied the least-cost path method together with SDMs and shared haplotypes to estimate their historical dispersal corridors. We identified three general scenarios of species distribution change during the late Quaternary: the 'contraction-expansion' scenario for species in the northeastern TP, the 'expansion-contraction' scenario for species in the southeast and the 'stable' scenario for widespread species. During the Quaternary, we identified that these species were likely to recolonize along the low-elevation valleys, huge mountain ranges and flat plateau platform (e.g. the Yarlung Zangbo Valley and the Himalaya. We inferred that Quaternary cyclic glaciations along with the various topographic and climatic conditions of the TP could have resulted in the diverse patterns of range shift and dispersal of Tibetan plant species. Finally, we believe that this study would provide valuable insights for the conservation of alpine species under future climate change.

  5. Role of quaternary additions on dislocated martensite, retain austenite and mechanical properties of Fe/Cr/C structural steels

    International Nuclear Information System (INIS)

    Rao, B.V.N.

    1978-02-01

    The influence of quaternary alloy additions of Mn and Ni to Fe/Cr/C steels which have been designed to provide superior mechanical properties has been investigated. Transmission electron microscopy and x-ray analysis revealed increasing amounts of retained austenite with Mn up to 2 w/o and with 5 w/o Ni additions after quenching from 1100 0 C. This is accompanied by a corresponding improvement in toughness properties of the quaternary alloys. In addition, the generally attractive combinations of strength and toughness in these quaternary alloys is attributed to the production of dislocated lath martensite from a homogeneous austenite phase free from undissolved alloy carbides. Grain-refining resulted in a further increase in the amount of retained austenite

  6. 40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.

    Science.gov (United States)

    2010-07-01

    ... fluorinated alkylaryl amide. 721.9075 Section 721.9075 Protection of Environment ENVIRONMENTAL PROTECTION... amide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as quaternary ammonium salt of fluorinated alkylaryl amide (PMN No. P-92-688) is...

  7. Spontaneous quaternary and tertiary T-R transitions of human hemoglobin in molecular dynamics simulation.

    Directory of Open Access Journals (Sweden)

    Jochen S Hub

    2010-05-01

    Full Text Available We present molecular dynamics simulations of unliganded human hemoglobin (Hb A under physiological conditions, starting from the R, R2, and T state. The simulations were carried out with protonated and deprotonated HC3 histidines His(beta146, and they sum up to a total length of 5.6 micros. We observe spontaneous and reproducible T-->R quaternary transitions of the Hb tetramer and tertiary transitions of the alpha and beta subunits, as detected from principal component projections, from an RMSD measure, and from rigid body rotation analysis. The simulations reveal a marked asymmetry between the alpha and beta subunits. Using the mutual information as correlation measure, we find that the beta subunits are substantially more strongly linked to the quaternary transition than the alpha subunits. In addition, the tertiary populations of the alpha and beta subunits differ substantially, with the beta subunits showing a tendency towards R, and the alpha subunits showing a tendency towards T. Based on the simulation results, we present a transition pathway for coupled quaternary and tertiary transitions between the R and T conformations of Hb.

  8. Microstructural aspects of manganese metal during its electrodeposition from sulphate solutions in the presence of quaternary amines

    International Nuclear Information System (INIS)

    Padhy, Subrat Kumar; Patnaik, P.; Tripathy, B.C.; Bhattacharya, I.N.

    2015-01-01

    Graphical abstract: - Highlights: • Quaternary amines produced smooth and bright manganese electrodeposits. • TEABr produced smooth and bright deposits with euhedral shaped crystals. • TBABr produced dendritic deposits with elongated poly-nodular crystals. • All the quaternary amines behaved as cathode polarisers. • TEABr was found to be the most efficient organic additive. - Abstract: In the present study investigation was made on the electrodeposition of manganese from sulphate solutions in the presence of quaternary amines TEABr, TPABr and TBABr. The concentrations of these additives were varied over a relatively broad range to evaluate their effect on the deposit morphology and preferred crystal orientations of the electrodeposited metal. TEABr resulted in bright and smooth manganese electrodeposits giving euhedral shape to the crystals with distinct triple junction points. TPABr also showed similar results at lower concentrations. However, TBABr resulted in the formation of dendritic growths with elongated poly-nodular crystals similar to that of Paragorgia corals having uniform multistep growths. The presence of these quaternary amines in the electrolyte causes polarisation of the cathode. TBABr being the strongest cathode polariser adsorbs strongly on the cathode resulting in poor deposit quality. TEABr was found to be the most efficient additive producing the desired quality manganese electrodeposit

  9. Quaternary association in β-prism I fold plant lectins: Insights from X ...

    Indian Academy of Sciences (India)

    The importance of quaternary association in the structure and function of proteins .... a locally maintained PDB-FTP anonymous server at the. Bioinformatics ... TIP4P water model using the program genbox available in the GROMACS suite.

  10. Practicing on Newly Dead

    Directory of Open Access Journals (Sweden)

    Jewel Abraham

    2015-07-01

    Full Text Available A newly dead cadaver simulation is practiced on the physical remains of the dead before the onset of rigor mortis. This technique has potential benefits for providing real-life in-situ experience for novice providers in health care practices. Evolving ethical views in health care brings into question some of the ethical aspects associated with newly dead cadaver simulation in terms of justification for practice, autonomy, consent, and the need of disclosure. A clear statement of policies and procedures on newly dead cadaver simulation has yet to be implemented. Although there are benefits and disadvantages to an in-situ cadaver simulation, such practices should not be carried out in secrecy as there is no compelling evidence that suggests such training as imperative. Secrecy in these practices is a violation of honor code of nursing ethics. As health care providers, practitioners are obliged to be ethically honest and trustworthy to their patients. The author explores the ethical aspects of using newly dead cadaver simulation in training novice nursing providers to gain competency in various lifesaving skills, which otherwise cannot be practiced on a living individual. The author explores multiple views on cadaver simulation in relation to ethical theories and practices such as consent and disclosure to family.

  11. Analysis of residual products in benzyl chloride used for the industrial synthesis of quaternary compounds by liquid chromatography with diode-array detection.

    Science.gov (United States)

    Prieto-Blanco, M C; López-Mahía, P; Prada-Rodríguez, D

    2009-02-01

    In industrial and pharmaceutical processes, the study of residual products becomes essential to guarantee the quality of compounds and to eliminate or minimize toxic residual products. Knowledge about the origin of impurities (raw materials, processes, the contamination of industrial plants, etc.) is necessary in preventive treatment and in the control of a product's lifecycle. Benzyl chloride is used as raw material to synthesize several quaternary ammonium compounds, such as benzalkonium chloride, which may have pharmaceutical applications. Benzaldehyde, benzyl alcohol, toluene, chloro derivatives of toluene, and dibenzyl ether are compounds that may be found as impurities in technical benzyl chloride. We proposed a high-performance liquid chromatography method for the separation of these compounds, testing two stationary phases with different dimensions and particle sizes, with the application of photodiode array-detection. The linearity for four possible impurities (benzaldehyde, toluene, alpha,alpha-dichlorotoluene, and 2-chlorotoluene) ranged from 0.1 to 10 microg/mL, limits of detection from 11 to 34 ng/mL, and repeatability from 1% to 2.9% for a 0.3-1.2 microg/mL concentration range. The method was applied to samples of technical benzyl chloride, and alpha,alpha-dichlorotoluene and benzaldehyde were identified by spectral analysis and quantitated. The selection of benzyl chloride with lower levels of impurities is important to guarantee the reduction of residual products in further syntheses.

  12. The competition of charge remote and charge directed fragmentation mechanisms in quaternary ammonium salt derivatized peptides--an isotopic exchange study.

    Science.gov (United States)

    Cydzik, Marzena; Rudowska, Magdalena; Stefanowicz, Piotr; Szewczuk, Zbigniew

    2011-12-01

    Derivatization of peptides as quaternary ammonium salts (QAS) is a promising method for sensitive detection by electrospray ionization tandem mass spectrometry (Cydzik et al. J. Pept. Sci. 2011, 17, 445-453). The peptides derivatized by QAS at their N-termini undergo fragmentation according to the two competing mechanisms - charge remote (ChR) and charge directed (ChD). The absence of mobile proton in the quaternary salt ion results in ChR dissociation of a peptide bond. However, Hofmann elimination of quaternary salt creates an ion with one mobile proton leading to the ChD fragmentation. The experiments on the quaternary ammonium salts with deuterated N-alkyl groups or amide NH bonds revealed that QAS derivatized peptides dissociate according to the mixed ChR-ChD mechanism. The isotopic labeling allows differentiation of fragments formed according to ChR and ChD mechanisms. © The Author(s) 2011. This article is published with open access at Springerlink.com

  13. Newly synthesized quinazolinone HMJ-38 suppresses angiogenetic responses and triggers human umbilical vein endothelial cell apoptosis through p53-modulated Fas/death receptor signaling

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Jo-Hua [Department of Life Sciences, National Chung Hsing University, 250, Kuo-Kuang Road, Taichung 402, Taiwan (China); Yang, Jai-Sing [Department of Pharmacology, China Medical University, Taichung 404, Taiwan (China); Lu, Chi-Cheng [Department of Life Sciences, National Chung Hsing University, 250, Kuo-Kuang Road, Taichung 402, Taiwan (China); Hour, Mann-Jen; Chang, Shu-Jen [School of Pharmacy, China Medical University, Taichung 40402, Taiwan (China); Lee, Tsung-Han, E-mail: thlee@email.nchu.edu.tw [Department of Life Sciences, National Chung Hsing University, 250, Kuo-Kuang Road, Taichung 402, Taiwan (China); Department of Biological Science and Technology, China Medical University, 91, Hsueh-Shih Road, Taichung 404, Taiwan (China); Chung, Jing-Gung, E-mail: jgchung@mail.cmu.edu.tw [Department of Biological Science and Technology, China Medical University, 91, Hsueh-Shih Road, Taichung 404, Taiwan (China); Department of Biotechnology, Asia University, Taichung 413, Taiwan (China)

    2013-06-01

    The current study aims to investigate the antiangiogenic responses and apoptotic death of human umbilical vein endothelial cells (HUVECs) by a newly synthesized compound named 2-(3′-methoxyphenyl)-6-pyrrolidinyl-4-quinazolinone (HMJ-38). This work attempted to not only explore the effects of angiogenesis on in vivo and ex vivo studies but also hypothesize the implications for HUVECs (an ideal cell model for angiogenesis in vitro) and further undermined apoptotic experiments to verify the underlying molecular signaling by HMJ-38. Our results demonstrated that HMJ-38 significantly inhibited blood vessel growth and microvessel formation by the mouse Matrigel plug assay of angiogenesis, and the suppression of microsprouting from the rat aortic ring assay was observed after HMJ-38 exposure. In addition, HMJ-38 disrupted the tube formation and blocked the ability of HUVECs to migrate in response to VEGF. We also found that HMJ-38 triggered cell apoptosis of HUVECs in vitro. HMJ-38 concentration-dependently suppressed viability and induced apoptotic damage in HUVECs. HMJ-38-influenced HUVECs were performed by determining the oxidative stress (ROS production) and ATM/p53-modulated Fas and DR4/DR5 signals that were examined by flow cytometry, Western blotting, siRNA and real-time RT-PCR analyses, respectively. Our findings demonstrate that p53-regulated extrinsic pathway might fully contribute to HMJ-38-provoked apoptotic death in HUVECs. In view of these observations, we conclude that HMJ-38 reduces angiogenesis in vivo and ex vivo as well as induces apoptosis of HUVECs in vitro. Overall, HMJ-38 has a potent anti-neovascularization effect and could warrant being a vascular targeting agent in the future. - Highlights: • HMJ-38 suppresses angiogenic actions in vivo and ex vivo. • Inhibitions of blood vessel and microvessel formation by HMJ-38 are acted. • Cytotoxic effects of HUVECs occur by HMJ-38 challenge. • p53-modulated extrinsic pathway contributes to HMJ-38

  14. Quaternary Magmatism in the Cascades - Geologic Perspectives

    Science.gov (United States)

    Hildreth, Wes

    2007-01-01

    Foreward The Cascade magmatic arc is a belt of Quaternary volcanoes that extends 1,250 km from Lassen Peak in northern California to Meager Mountain in Canada, above the subduction zone where the Juan de Fuca Plate plunges beneath the North American Plate. This Professional Paper presents a synthesis of the entire volcanic arc, addressing all 2,300 known Quaternary volcanoes, not just the 30 or so visually prominent peaks that comprise the volcanic skyline. Study of Cascade volcanoes goes back to the geological explorers of the late 19th century and the seminal investigations of Howel Williams in the 1920s and 1930s. However, major progress and application of modern scientific methods and instrumentation began only in the 1970s with the advent of systematic geological, geophysical, and geochemical studies of the entire arc. Initial stimulus from the USGS Geothermal Research Program was enhanced by the USGS Volcano Hazards Program following the 1980 eruption of Mount St. Helens. Together, these two USGS Programs have provided more than three decades of stable funding, staffing, and analytical support. This Professional Paper summarizes the resultant USGS data sets and integrates them with the parallel contributions of other investigators. The product is based upon an all-encompassing and definitive geological database, including chemical and isotopic analyses to characterize the rocks and geochronology to provide the critical time constraints. Until now, this massive amount of data has not been summarized, and a systematic and uniform interpretation firmly grounded in geological fact has been lacking. Herein lies the primary utility of this Cascade volume. It not only will be the mandatory starting point for new workers, but also will provide essential geological context to broaden the perspectives of current investigators of specific Cascade volcanoes. Wes Hildreth's insightful understanding of volcanic processes and his uncompromising scientific integrity make him

  15. Species-specific responses of Late Quaternary megafauna to climate and humans

    DEFF Research Database (Denmark)

    Lorenzen, Eline; Nogues, David Bravo; Orlando, Ludovic Antoine Alexandre

    2011-01-01

    Despite decades of research, the roles of climate and humans in driving the dramatic extinctions of large-bodied mammals during the Late Quaternary period remain contentious. Here we use ancient DNA, species distribution models and the human fossil record to elucidate how climate and humans shape...

  16. Quaternary isobaric (vapor + liquid + liquid) equilibrium and (vapor + liquid) equilibrium for the system (water + ethanol + cyclohexane + heptane) at 101.3 kPa

    International Nuclear Information System (INIS)

    Pequenin, Ana; Asensi, Juan Carlos; Gomis, Vicente

    2011-01-01

    Highlights: → Water-ethanol-cyclohexane-heptane and water-cyclohexane-heptane isobaric VLLE. → Isobaric experimental data were determined at 101.3 kPa. → A dynamic recirculating still with an ultrasonic homogenizer was used. → The quaternary system does not present quaternary azeotropes. - Abstract: Experimental isobaric (vapor + liquid + liquid) and (vapor + liquid) equilibrium data for the ternary system {water (1) + cyclohexane (2) + heptane (3)} and the quaternary system {water (1) + ethanol (2) + cyclohexane (3) + heptane (4)} were measured at 101.3 kPa. An all-glass, dynamic recirculating still equipped with an ultrasonic homogenizer was used to determine the VLLE. The results obtained show that the system does not present quaternary azeotropes. The point-by-point method by Wisniak for testing the thermodynamic consistency of isobaric measurements was used to test the equilibrium data.

  17. Experimental and thermodynamic study of the Mg–Sn–In–Zn quaternary system

    International Nuclear Information System (INIS)

    Wang, Jian; Hudon, Pierre; Kevorkov, Dmytro; Chartrand, Patrice; Jung, In-Ho; Medraj, Mamoun

    2014-01-01

    Highlights: • Phase equilibria in the Mg-rich region of the Mg–Sn–In are determined. • Phase equilibria in the Mg-rich region of the Mg–Sn–Zn are determined. • Evaluation and thermodynamic optimization of the Mg–Sn–In–Zn quaternary system are developed. -- Abstract: Phase equilibria in the Mg-rich region of the Mg–Sn–In (at 415 °C and 330 °C), and Mg–Sn–Zn (at 300 °C) ternary systems were determined by quenching experiments, electron probe micro-analyzer (EPMA), and X-ray diffraction (XRD) techniques. The ternary isoplethal sections with constant 5 In and 10 Sn at.% of Mg–In–Sn system, and 10 Sn at.% of Mg–In–Zn system were determined by differential scanning calorimetry (DSC). No ternary compounds were found in the Mg–Sn–Zn and Mg–Sn–In isothermal sections. Critical evaluation and thermodynamic optimization of the Mg–Sn–In–Zn quaternary system were carried out using CALPHAD (Calculation of Phase Diagrams) technique. The Modified Quasichemical Model in the Pair Approximation (MQMPA) was used for modeling the liquid solution, which exhibits a high degree of short-range ordering behavior. The solid phases were modeled with the Compound Energy Formalism (CEF). All available and reliable experimental data were reproduced within experimental error limits. A self-consistent thermodynamic database was constructed for the Mg–Sn–In–Zn quaternary system, which can be used as a guide for Mg-based alloys development

  18. Three-Dimensional Geological Model of Quaternary Sediments in Walworth County, Wisconsin, USA

    Directory of Open Access Journals (Sweden)

    Jodi Lau

    2016-07-01

    Full Text Available A three-dimensional (3D geologic model was developed for Quaternary deposits in southern Walworth County, WI using Petrel, a software package primarily designed for use in the energy industry. The purpose of this research was to better delineate and characterize the shallow glacial deposits, which include multiple shallow sand and gravel aquifers. The 3D model of Walworth County was constructed using datasets such as the U.S. Geological Survey 30 m digital elevation model (DEM of land surface, published maps of the regional surficial geology and bedrock topography, and a database of water-well records. Using 3D visualization and interpretation tools, more than 1400 lithostratigraphic picks were efficiently interpreted amongst 725 well records. The final 3D geologic model consisted of six Quaternary lithostratigraphic units and a bedrock horizon as the model base. The Quaternary units include in stratigraphic order from youngest to oldest: the New Berlin Member of the Holy Hill Formation, the Tiskilwa Member of the Zenda Formation, a Sub-Tiskilwa Sand/Gravel unit, the Walworth Formation, a Sub-Walworth Sand/Gravel unit, and a Pre-Illinoisan unit. Compared to previous studies, the results of this study indicate a more detailed distribution, thickness, and interconnectivity between shallow sand and gravel aquifers and their connectivity to shallow bedrock aquifers. This study can also help understand uncertainty within previous local groundwater-flow modeling studies and improve future studies.

  19. Thermoelectric properties of quaternary (Bi,Sb){sub 2}(Te,Se){sub 3} compound

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Pengfei, E-mail: photon.bupt@gmail.com [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Li, Yiluan; Wu, Chengjie; Yu, Zhongyuan; Cao, Huawei; Zhang, Xianlong; Cai, Ningning; Zhong, Xuxia [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Wang, Shumin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Photonics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Gothenburg (Sweden)

    2014-01-25

    Highlights: • Sb and Se spin–orbit coupling play a key role in the band structure. • Substituted Bi/Sb and Te/Se have a limited impact on the transport coefficients. • n-Type doping will be preferred for quaternary (Bi,Sb){sub 2}(Te,Se){sub 3} compound. -- Abstract: The quaternary (Bi,Sb){sub 2}(Te,Se){sub 3} compounds are investigated using first-principles study and Boltzmann transport theory. The energy band structure and density of states are studied in detail. The electronic transport coefficients are then calculated as a function of chemical potential. The figure of merit ZT is obtained assuming a constant relaxation time and an averaged thermal conductivity. Our theoretical result agrees well with previous experimental data.

  20. Integrating Quaternary science research in land management, restoration, and conservation

    Science.gov (United States)

    C.I. Millar; W.B. Woolfenden

    2001-01-01

    Most of us have come to expect that the general public will ignore the primary message of Quaternary science that change happens. A flurry, however, of recent media attention to 20th-century global warming and its anomalies from climates of the last millennium has brought climate science at least momentarily into popular focus. Similarly, public land-managing agencies...

  1. Performance properties and antibacterial activity of crosslinked films of quaternary ammonium modified starch and poly(vinyl alcohol).

    Science.gov (United States)

    Sekhavat Pour, Zahra; Makvandi, Pooyan; Ghaemy, Mousa

    2015-09-01

    There has been a growing interest in developing antibacterial polymeric materials. In the present work, novel antibacterial cross-linked blend films were prepared based on polyvinyl alcohol (PVA) and quaternary ammonium starch (ST-GTMAC) using citric acid (CA) as plasticizer and glutaraldehyde (GA) as cross-linker. The ST-GTMAC was successfully synthesized from reaction between water-soluble oxidized starch and glycidyltrimethylammonium chloride (GTMAC). The effect of ST-GTMAC, CA and GA contents on the swelling, solubility, mechanical and thermal properties of the films was investigated. It was found that incorporation of ST-GTMAC reduced UV-transmittance and provided antibacterial properties, increasing GA content increased tensile strength and decreased solubility and swelling degree of the films, while CA acted as plasticizer when its concentration was above 10 wt%. The results showed that ST-GTMAC/PVA/CA/GA film has fair antibacterial activity against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. These results suggest that the prepared film might be used as potential antibacterial material in medical and packaging applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Reduction of quaternary ammonium-induced ocular surface toxicity by emulsions: an in vivo study in rabbits.

    Science.gov (United States)

    Liang, H; Brignole-Baudouin, F; Rabinovich-Guilatt, L; Mao, Z; Riancho, L; Faure, M O; Warnet, J M; Lambert, G; Baudouin, C

    2008-01-31

    To evaluate and compare the toxicological profiles of two quaternary ammonium compounds (QAC), benzalkonium chloride (BAK), and cetalkonium chloride (CKC), in standard solution or cationic emulsion formulations in rabbit eyes using newly developed in vivo and ex vivo experimental approaches. Seventy eyes of 35 adult male New Zealand albino rabbits were used in this study. They were randomly divided into five groups: 50 microl of phosphate-buffered saline (PBS), PBS containing 0.02% BAK or 0.002% CKC (BAK Sol and CKC Sol, respectively), and emulsion containing 0.02% BAK or 0.002% CKC (BAK Em and CKC Em, respectively) were applied to rabbit eyes 15 times at 5-min intervals. The ocular surface changes induced by these eye drops were investigated using slit-lamp examination, flow cytometry (FCM), impression cytology (IC) on conjunctiva, and corneal in vivo confocal microscopy (IVCM). Standard immunohistology in cryosections was also examined for cluster of differentiation (CD) 45+ infiltrating and terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL)+ apoptotic cells. Clinical observations and IVCM showed that the highest toxicity was induced by BAK Sol, characterized by damaged corneal epithelium and a high level of inflammatory infiltration. BAK Em and CKC Sol presented moderate effects, and CKC Em showed the lowest toxicity with results similar to those of PBS. Conjunctival imprints analyzed by FCM showed a higher expression of RLA-DR and TNFR1 markers in BAK Sol-instilled eyes than in all other groups, especially at 4 h. Immunohistology was correlated with in vivo and ex vivo findings and confirmed this toxicity profile. A high level of infiltration of CD45+ inflammatory cells and TUNEL+ apoptotic cells was observed in limbus and conjunctiva, especially in QAC solution-receiving eyes compared to QAC emulsion-instilled eyes. The acute administration of 15 instillations at 5 min intervals was a rapid and efficient model to assess quaternary

  3. First-principles study of new quaternary Heusler compounds without 3d transition metal elements: ZrRhHfZ (Z = Al, Ga, In)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaotian [School of Material Sciences and Engineering, Hebei University of Technology, Tianjin 300130 (China); Institute for Superconducting & Electronic Materials (ISEM), University of Wollongong, Wollongong 2500 (Australia); Cheng, Zhenxiang, E-mail: cheng@uow.edu.au [Institute for Superconducting & Electronic Materials (ISEM), University of Wollongong, Wollongong 2500 (Australia); Guo, Ruikang [School of Material Sciences and Engineering, Hebei University of Technology, Tianjin 300130 (China); Wang, Jianli [Institute for Superconducting & Electronic Materials (ISEM), University of Wollongong, Wollongong 2500 (Australia); Rozale, Habib [Condensed Matter and Sustainable Development Laboratory, Physics Department, University of Sidi-Bel-Abbès, 22000 Sidi-Bel-Abbès (Algeria); Wang, Liying [Department of Physics, Tianjin University, Tianjin 300350 (China); Yu, Zheyin [Institute for Superconducting & Electronic Materials (ISEM), University of Wollongong, Wollongong 2500 (Australia); Liu, Guodong, E-mail: gdliu1978@126.com [School of Material Sciences and Engineering, Hebei University of Technology, Tianjin 300130 (China)

    2017-06-01

    Plane-wave pseudo-potential methods based on density functional theory are employed to investigate the electronic structures, and the magnetic and half-metallic properties of the newly designed quaternary Heusler compounds ZrRhHfZ (Z = Al, Ga, In) without 3d transition metal elements. The calculated results show that ZrRhHfZ (Z = Al, Ga, In) compounds are half-metallic, with 100% spin polarization around the Fermi level. The structural stability of these compounds has been tested from the aspects of their cohesion energy and formation. The spin-flip/half-metallic gaps of ZrRhHfZ (Z = Al, Ga, In) compounds are quite large, with values of 0.2548 eV, 0.3483 eV, and 0.2866 eV, respectively. These compounds show Slater-Pauling behavior, and the total spin magnetic moment per unit cell (M{sub t}) scales with the total number of valence electrons (Z{sub t}) following the rule: M{sub t} = Z{sub t} - 18. The magnetization of ZrRhHfZ (Z = Al, Ga, In) compounds mainly comes from the 4d electrons of the Zr atoms and the 5d electrons of the Hf atoms. Furthermore, the effects of uniform strain and tetragonal deformation on the half metallicity has been investigated in detail, which is important for practical application. Finally, we reveal that the half-metallicity can be maintained when the Coulomb interactions are considered. - Highlights: • New quaternary compounds without 3d transition metal elements have been designed. • The electronic structures and magnetism of the ZrRhHfZ compounds have been studied. • The effect of strain on the half-metallic behavior has been tested. • The effect of the Coulomb interactions on the half-metallicity has been investigated.

  4. Late Tertiary and Quaternary geology of the Tecopa basin, southeastern California

    Energy Technology Data Exchange (ETDEWEB)

    Hillhouse, J.W.

    1987-12-31

    Stratigraphic units in the Tecopa basin, located in southeastern California, provide a framework for interpreting Quaternary climatic change and tectonism along the present Amargosa River. During the late Pliocene and early Pleistocene, a climate that was appreciably wetter than today`s sustained a moderately deep lake in the Tecopa basin. Deposits associated with Lake Tecopa consists of lacustrine mudstone, conglomerate, volcanic ash, and shoreline accumulations of tufa. Age control within the lake deposits is provided by air-fall tephra that are correlated with two ash falls from the Yellowstone caldera and one from the Long Valley caldera. Lake Tecopa occupied a closed basin during the latter part, if not all, of its 2.5-million-year history. Sometime after 0.5 m.y. ago, the lake developed an outlet across Tertiary fanglomerates of the China Ranch Beds leading to the development of a deep canyon at the south end of the basin and establishing a hydrologic link between the northern Amargosa basins and Death Valley. After a period of rapid erosion, the remaining lake beds were covered by alluvial fans that coalesced to form a pediment in the central part of the basin. Holocene deposits consist of unconsolidated sand and gravel in the Amargosa River bed and its deeply incised tributaries, a small playa near Tecopa, alluvial fans without pavements, and small sand dunes. The pavement-capped fan remnants and the Holocene deposits are not faulted or tilted significantly, although basins to the west, such as Death Valley, were tectonically active during the Quaternary. Subsidence of the western basins strongly influenced late Quaternary rates of deposition and erosion in the Tecopa basin.

  5. Enhancement of device performance by using quaternary capping over ternary capping in strain-coupled InAs/GaAs quantum dot infrared photodetectors

    International Nuclear Information System (INIS)

    Tongbram, B.; Shetty, S.; Ghadi, H.; Adhikary, S.; Chakrabarti, S.

    2015-01-01

    We investigate and compare the performance of 30 layers strain-coupled quantum dot (SCQD) infrared photodetectors capped with one of two different layers: a quaternary (In 0.21 Al 0.21 Ga 0.58 As) or ternary (In 0.15 Ga 0.85 As) alloy of 30 Aa and a GaAs layer with a thickness of 120-150 Aa. Measurements of optical properties, spectral responsivity, and cross-sectional transmission electron microscopy were conducted. Results showed that quaternary capping yielded more superior multilayer QD infrared photodetectors than ternary capping. Quaternary capping resulted in enhanced dot size, order, and uniformity of the QD array. The presence of Al in the capped layer helped in the reduction in dark current density and spectral linewidth as well as led to higher electron confinement of the QDs and enhanced device detectivity. The vertically ordered SCQD system with quaternary capping exhibited higher peak detectivity (∝10 10 cm Hz 1/2 /W) than that with ternary capping (∝10 7 cm Hz 1/2 /W). In addition, a very low noise current density of ∝10 -16 A/cm 2 Hz 1/2 at 77 K was achieved with quaternary-capped QDs. (orig.)

  6. Newly graduated nurses' use of knowledge sources

    DEFF Research Database (Denmark)

    Voldbjerg, Siri Lygum; Grønkjaer, Mette; Sørensen, Erik Elgaard

    2016-01-01

    AIM: To advance evidence on newly graduated nurses' use of knowledge sources. BACKGROUND: Clinical decisions need to be evidence-based and understanding the knowledge sources that newly graduated nurses use will inform both education and practice. Qualitative studies on newly graduated nurses' use...... underscoring progression in knowledge use and perception of competence and confidence among newly graduated nurses. CONCLUSION: The transition phase, feeling of confidence and ability to use critical thinking and reflection, has a great impact on knowledge sources incorporated in clinical decisions....... The synthesis accentuates that for use of newly graduated nurses' qualifications and skills in evidence-based practice, clinical practice needs to provide a supportive environment which nurtures critical thinking and questions and articulates use of multiple knowledge sources....

  7. A new quaternary phase observed in a laser treated Zn–Al–Mg–Si coating

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z., E-mail: zchen@uowmail.edu.au [School of Mechanical, Materials and Mechatronic Engineering, Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, NSW 2522 (Australia); Peng, C.-T. [School of Mechanical, Materials and Mechatronic Engineering, Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, NSW 2522 (Australia); Liu, Q.; Smith, R.; Nolan, D. [Bluescope Steel Research, Bluescope Steel Limited, Locked Bag 8825, Wollongong DC, NSW 2500 (Australia)

    2014-03-15

    Highlights: • A new quaternary phase was discovered in laser treated Zn–55Al–2Mg–1Si coating. • The crystal structure of the new phase was determined by TEM. • The new phase was not a metastable phase induced by the rapid cooling of the laser treatment. • Laser treatment led to not only a much finer microstructure but also changes of phases in the interdendritic areas of the coating. -- Abstract: The microstructure of laser resurfaced Zn–55Al–2Mg–1.5Si coating produced on a hot-dip simulator was characterised by transmission electron microscopy. A new quaternary phase was observed and its crystal structure was determined by electron diffraction.

  8. A new quaternary phase observed in a laser treated Zn–Al–Mg–Si coating

    International Nuclear Information System (INIS)

    Chen, Z.; Peng, C.-T.; Liu, Q.; Smith, R.; Nolan, D.

    2014-01-01

    Highlights: • A new quaternary phase was discovered in laser treated Zn–55Al–2Mg–1Si coating. • The crystal structure of the new phase was determined by TEM. • The new phase was not a metastable phase induced by the rapid cooling of the laser treatment. • Laser treatment led to not only a much finer microstructure but also changes of phases in the interdendritic areas of the coating. -- Abstract: The microstructure of laser resurfaced Zn–55Al–2Mg–1.5Si coating produced on a hot-dip simulator was characterised by transmission electron microscopy. A new quaternary phase was observed and its crystal structure was determined by electron diffraction

  9. separation of strontium and cesium from ternary and quaternary lithium chloride-potassium chloride salts via melt crystallization

    Directory of Open Access Journals (Sweden)

    Ammon N. Williams

    2015-12-01

    Full Text Available Separation of cesium chloride (CsCl and strontium chloride (SrCl2 from the lithium chloride-potassium chloride (LiCl-KCl salt was studied using a melt crystallization process similar to the reverse vertical Bridgeman growth technique. A ternary SrCl2-LiCl-KCl salt was explored at similar growth rates (1.8–5 mm/h and compared with CsCl ternary results to identify similarities. Quaternary experiments were also conducted and compared with the ternary cases to identify trends and possible limitations to the separations process. In the ternary case, as much as 68% of the total salt could be recycled per batch process. In the quaternary experiments, separation of Cs and Sr was nearly identical at the slower rates; however, as the growth rate increased, SrCl2 separated more easily than CsCl. The quaternary results show less separation and rate dependence than in both ternary cases. As an estimated result, only 51% of the total salt could be recycled per batch. Furthermore, two models have been explored to further understand the growth process and separation. A comparison of the experimental and modeling results reveals that the nonmixed model fits reasonably well with the ternary and quaternary data sets. A dimensional analysis was performed and a correlation was identified to semipredict the segregation coefficient.

  10. Separation of strontium and cesium from ternary and quaternary lithium chloride-potassium chloride salts via melt crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Ammon n.; Pack, Michael [Dept. of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond (United States); Phongikaroon, Spathorn [Dept. of Chemical and Materials Engineering and Nuclear Engineering Program, University of Idaho, Idaho Falls (United States)

    2015-12-15

    Separation of cesium chloride (CsCl) and strontium chloride (SrCl{sub 2}) from the lithium chloride-potassium chloride (LiCl-KCl) salt was studied using a melt crystallization process similar to the reverse vertical Bridgeman growth technique. A ternary SrCl2-LiCl-KCl salt was explored at similar growth rates (1.8-5 mm/h) and compared with CsCl ternary results to identify similarities. Quaternary experiments were also conducted and compared with the ternary cases to identify trends and possible limitations to the separations process. In the ternary case, as much as 68% of the total salt could be recycled per batch process. In the quaternary experiments, separation of Cs and Sr was nearly identical at the slower rates; however, as the growth rate increased, SrCl{sub 2} separated more easily than CsCl. The quaternary results show less separation and rate dependence than in both ternary cases. As an estimated result, only 51% of the total salt could be recycled per batch. Furthermore, two models have been explored to further understand the growth process and separation. A comparison of the experimental and modeling results reveals that the nonmixed model fits reasonably well with the ternary and quaternary data sets. A dimensional analysis was performed and a correlation was identified to semipredict the segregation coefficient.

  11. Ecosystem resilience to abrupt late Quaternary change in continental southern Siberia

    Science.gov (United States)

    Harding, Poppy; Mackay, Anson; Bezrukova, Elena; Shchetnikov, Alexander

    2017-04-01

    Quaternary climate variability is dominated by long term orbital forcing along with abrupt sub-Milankovitch events on the scales of millennia to centuries, driven by internal feedback mechanisms, volcanic forcing and fluctuating solar activity. Although these are well documented in the North Atlantic region, their expression is poorly understood in Siberia, particularly in relation to abrupt climatic events. Siberia has the world's highest level of continentality offering an opportunity to study changes remote from oceanic influences and improving understanding of interactions between the Siberian High and other atmospheric systems including the Aleutian Low, Arctic oscillation and Icelandic Low1 and ENSO2. Understanding of palaeoenvironmental change in Siberia is essential due to the region's high sensitivity to climatic change, with warming rates considerably higher than the global average over the past 50 years3, triggering significant environmental changes, including permafrost degradation, shifts in the forest-steppe biome, increases in forest fires and warming of seasonally ice-covered lakes. Additionally, the region provides essential palaeoenvironmental context for early hominins, for example at globally important sites such as Denisova cave4, and megafauna extinctions5. This presentation outlines ongoing work at Lake Baunt, SE Siberia including: key quaternary climate forcings, the site and its regional context, the key methods and preliminary results. These include a dated record back to ˜30ka BP (based on multiple 14C dates and Bayesian age modelling), multiproxy indicators of palaeoproductivity (e.g. biogenic silica and diatom analyses) and lake mixing regimes (inferred from diatom analyses). Together these highlight several key Quaternary fluctuations potentially correlated to events recorded in Greenland Ice Cores (GS2, GS2.1, GI1, GS1), and these are considered against key Quaternary records including those from nearby Lake Baikal and Hulu Cave in

  12. Thermodynamic modeling of ternary and quaternary (liquid + liquid) systems containing water, FeCl3, HCl and diisopropyl ether

    International Nuclear Information System (INIS)

    Milosevic, Miran; Hendriks, Ilse; Smits, Ralph E.R.; Schuur, Boelo; Haan, André B. de

    2013-01-01

    Highlights: • Literature data from various sources was validated experimentally. • Ternary and quaternary (liquid + liquid) systems were successfully described with the NRTL model. • Some deflection at higher HCl concentrations between model and data. • Additional data verification proved correctness of the literature data. -- Abstract: Liquid–liquid extraction using ethers as solvents is a potentially energy saving alternative for the concentration of aqueous ferric chloride solutions. Adequate thermodynamic models that describe the behavior of the resulting quaternary systems (FeCl 3 , ether, acid and water) are not available in the literature. In this paper, the development of an equilibrium description applying the NRTL-model is presented, including experimental validation and fitting of the NRTL-parameters on the validated data. Equilibrium experiments were performed for the ternary systems (water + HCl + DiPE) and (water + FeCl 3 + DiPE) and the obtained data is in good agreement with the results from Maljkovic et al.[37] and Cambell et al.[39]. Experimental data of the quaternary system is taken from Maljkovic et al.[37]. The obtained binary interaction parameters to describe the (liquid + liquid) quaternary system (water + FeCl 3 + HCl + DiPE) and the constituting ternaries by the NRTL model are presented. Model predictions are in good agreement with the experimental data

  13. Evaluation of quaternary ammonium halides for removal of methyl iodide from flowing air streams

    International Nuclear Information System (INIS)

    Freeman, W.P.; Mohacsi, T.G.; Kovach, J.L.

    1985-01-01

    The quaternary ammonium halides of several tertiary amines were used as impregnants on activated carbon and were tested for methyl iodide penetration in accordance with test Method A, ASTM D3803, 1979, ''Standard Test Methods for Radio-iodine Testing of Nuclear Grade Gas Phase Adsorbents''. The results suggest that the primary removal mechanism for methyl iodide-131 is isotopic exchange with the quaternary ammonium halide. For example, a 5 wt% impregnation of each of the tetramethyl, tetraethyl, tetrapropyl and tetrabutyl ammonium iodides on activated carbon yielded percent penetrations of 0.47, 0.53, 0.78, and 0.08 respectively when tested according to Method A of ASTM D3803. A sample impregnated with 5% tetramethyl ammonium hydroxide gave a methyl iodide penetration of 64.87%, thus supporting the isotopic exchange mechanism for removal. It has been a generally held belief that the success of tertiary amines as impregnants for radioiodine removal is a result of their ability to complex with the methyl iodide. The results of the work indicates that the superiority of the tertiary amines similar to triethylene diamine and quinuclidine, when compared to their straight chain analogs, is a result of their ease in reacting with methyl iodide-127 to form the quaternary ammonium iodide followed by isotopic exchange

  14. Plio-Quaternary tectonic evolution off Al Hoceima, Moroccan Margin of the Alboran Basin.

    Science.gov (United States)

    Lafosse, Manfred; d'Acremont, Elia; Rabaute, Alain; Mercier de Lépinay, Bernard; Gorini, Christian; Ammar, Abdellah; Tahayt, Abdelilah

    2015-04-01

    We use data from a compilation of industrial and academic 2D surveys and recent data from MARLBORO-1 (2011), MARLBORO-2 (2012), and SARAS (2012) surveys, which provide high resolution bathymetry and 2D seismic reflexion data. We focus on the key area located south of the Alboran Ridge and the Tofiño Bank, and encompassing the Nekor and Boudinar onshore-offshore basins on the Moroccan side of the Alboran Sea. The Nekor basin is a present pull-apart basin in relay between inherited N050° sinistral strike-slip faults. We consider that these faults define the Principal Displacement Zones (PDZ). The northern PDZ marks the position of the crustal Bokkoya fault, which is connected to the Al-Idrisi Fault Zone en relais with the Adra and Carboneras Fault Zones. On the seabed, right-stepping non-coalescent faults characterize the sinistral kinematics of the northern PDZ and give a general N050° azimuth for the crustal discontinuity. The southern PDZ corresponds to the Nekor fault Zone, a Miocene sinistral strike-slip fault acting as the structural limit of the External Rif. On its eastern edge, the Nekor basin is bounded by the N-S onshore-offshore Trougout fault, connecting the northern and the southern PDZ. The western boundary of the Nekor basin is marked by the Rouadi and El-Hammam Quaternary active N-S normal faults. In the offshore Nekor basin, recent N155° conjugated normal faults affect the seabed. Further east, the Boudinar basin is a Plio-Quaternary uplifted Neogene basin. The northeastern segment of the Nekor fault bounds this basin to the south but is inactive in the Quaternary. Normal east-dipping N150° faults are visible offshore in the continuity of the Boudinar fault. From our perspective, the orientation of major tectonic structures (Bokkoya, Nekor and Carboneras faults and the Alboran ridge) under the present compressive regime due to the Europe/Africa convergence is not compatible with a strike-slip motion. The orientation of the most recent Plio-Quaternary

  15. Research on the neutron flux, secular equilibrium of chlorine-36 and groundwater age of the deep quaternary sediments, Hebei plain

    International Nuclear Information System (INIS)

    Dong Yuean; He Ming; Jiang Songsheng; Wu Shaoyong; Jiang Shan

    2001-01-01

    For the study of the neutron flux, secular equilibrium of chlorine-36 in the deep quaternary sediments of Hebei plain, the main chemical composition of water sand and confining bed was determined by neutron activation analysis. The mean neutron flux is 2.79 x 10 -5 cm -2 s -1 which was calculated by the chemical composition of the strata. The mean 36 Cl/Cl ratio in secular equilibrium is 1.27 x 10 -14 in the deep quaternary sediments, Hebei Plain. For the study of the groundwater age of the deep Quaternary sediments of Hebei Plain, the 36 Cl/Cl ratio of groundwater samples were determined by tandem accelerator mass spectrometry. The mixed groundwater 36 Cl/Cl ratio of the second and the third aquifer of Quaternary sediments in Baoding district is 247 x 10 -15 , that of the fourth aquifer in Baoding city is 224 x 10 -15 and the third aquifer in Cangzhou district is 40.5 x 10 -15 . The groundwater age of Baoding district was young and that of the third aquifer in Cangzhou was 229.2 ka

  16. Epoxidation of Alkenes with Aqueous Hydrogen Peroxide and Quaternary Ammonium Bicarbonate Catalysts

    DEFF Research Database (Denmark)

    Mielby, Jerrik Jørgen; Kegnæs, Søren

    2013-01-01

    A range of solid and liquid catalysts containing bicarbonate anions were synthesised and tested for the epoxidation of alkenes with aqueous hydrogen peroxide. The combination of bicarbonate anions and quaternary ammonium cations opens up for new catalytic systems that can help to overcome...

  17. Novel immobilization of a quaternary ammonium moiety on keratin fibers for medical applications.

    Science.gov (United States)

    Yu, Dan; Cai, Jackie Y; Liu, Xin; Church, Jeffrey S; Wang, Lijing

    2014-09-01

    This paper introduces a new approach for immobilizing a quaternary ammonium moiety on a keratinous substrate for enhanced medical applications. The method involves the generation of thiols by controlled reduction of cystine disulfide bonds in the keratin, followed by reaction with [2-(acryloyloxy)ethyl]trimethylammonium chloride through thiol-ene click chemistry. The modified substrate was characterized with Raman and infrared spectroscopy, and assessed for its antibacterial efficacy and other performance changes. The results have demonstrated that the quaternary ammonium moiety has been effectively attached onto the keratin structure, and the resultant keratin substrate exhibits a multifunctional effect including antibacterial and antistatic properties, improved liquid moisture management property, improved dyeability and a non-leaching characteristic of the treated substrate. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  18. Ascomycin macrolactam derivative SDZ ASM 981 inhibits the release of granule-associated mediators and of newly synthesized cytokines in RBL 2H3 mast cells in an immunophilin-dependent manner.

    Science.gov (United States)

    Hultsch, T; Müller, K D; Meingassner, J G; Grassberger, M; Schopf, R E; Knop, J

    1998-09-01

    Mast cells play an important role in the pathological development of many inflammatory and allergic diseases and inhibition of mast cell activation is a potential target for therapeutic intervention. Therefore, the effect of the novel ascomycin macrolactam derivative SDZ ASM 981 on Fc epsilonRI-mediated activation of rat basophilic leukemia (RBL) cells, as a model for mast cell activation, was investigated. First, the ability to inhibit different mast cell immunophilins in vitro was tested. Using recombinant macrophilin-12 (FKBP-12), inhibition of rotamase activity with an IC50 of approximately 6 nM was observed. The rotamase activity of cyclophilin A (18 kDa) was not affected. Secondly, the effect of SDZ ASM 981 on Fc epsilonRI-mediated mast cell activation was investigated in the RBL cell model. SDZ ASM 981 inhibited exocytosis of preformed mediators (e.g. serotonin) with an IC50 of approximately 30 nM. Transcription and release of newly synthesized mediators (e.g. TNF-alpha) was inhibited with an IC50 of approximately 100 nM. The inhibitory effect of SDZ ASM 981 was antagonized by rapamycin. We conclude that SDZ ASM 981 is a potent inhibitor of Fc epsilonRI-mediated activation of mast cells in vitro. The mechanism of action involves formation of (calcineurin) inhibitory complexes with macrophilins. We suggest that this inhibitory action on mast cells might contribute to the antiinflammatory effect of SDZ ASM 981 observed in vivo (e.g. in aptopic dermatitis and psoriasis).

  19. Soil-landscape development and late Quaternary environmental change in coastal Estremadura, Portugal

    Science.gov (United States)

    Daniels, Michael; Haws, Jonathan; Benedetti, Michael; Bicho, Nuno

    2015-04-01

    This poster integrates soil-landscape analysis with archaeological survey and paleoenvironmental reconstruction. Soils in surface and buried contexts in Estremadura, Portugal, provide evidence of landscape stability and instability, relative age relationships between landforms, and general paleoenvironmental conditions during the late Quaternary. These factors provide insight into the distribution and condition of Paleolithic archaeological sites and help understand the record of human settlement in the region. Late Pleistocene and Holocene dunes extend inland approximately 10 km from coastal source regions. Surface soils in Holocene dunes under maritime pine (Pinus pinaster) forest exhibit A, E, C/Bh and A, C horizon sequences and classify as Quartzipsamments. Surface soils in late Pleistocene dunes exhibit A, E, Bh, Bhs, Bs horizon sequences and classify as Haplorthods. Both Pleistocene and Holocene dunes commonly bury a heavily weathered soil formed in calcareous sandstone. The boundary between underlying buried soils and overlying surface soils is characterized by a lag deposit of medium to coarse, moderately-rounded gravels, underlain immediately by subsurface Bt and Bss horizons. The lag deposit and absence of buried A horizons both indicate intense and/or prolonged surface erosion prior to burial by late Quaternary dunes. Soil-geomorphic relationships therefore suggest at least two distinct episodes of dune emplacement and subsequent landscape stability following an extensive episode late Pleistocene landscape instability and soil erosion. A conceptual model of soil-landscape evolution through the late Quaternary and Holocene results from the integration of soil profile data, proxy paleoenvironmental data, and the partial record of human settled as revealed in the archaeological record.

  20. Recycling endosomes in human cytotoxic T lymphocytes constitute an auxiliary intracellular trafficking pathway for newly synthesized perforin

    Science.gov (United States)

    Lesteberg, Kelsey E.; Orange, Jordan S.; Makedonas, George

    2018-01-01

    Background Although cytotoxic T lymphocytes (CTLs) store perforin within cytoplasmic secretory granules for immediate use, perforin is synthesized anew within hours of TCR stimulation. Previously, we observed new perforin protein at an immunologic synapse independent of secretory lysosomes; herein we aimed to determine how new perforin transits to the synapse if not via lytic granules. Results We analyzed antigen-specific human CTLs via imaging flow cytometry and high-resolution confocal microscopy, with attention to intracellular trafficking components and new perforin. The recycling endosome compartments identified by rab8, rab11a, rab4, and rab37 co-localized with new perforin, as well as the SNAREs vti1b and VAMP4. After ablating the function of the recycling endosome pathway, we observed a relative accumulation of new perforin in rab8 vesicles. Conclusions The recycling endosome pathway may serve as an auxiliary intracellular route for the delivery of new perforin to an immunologic synapse in order to perpetuate a cytotoxic response. PMID:28822075

  1. Mineralogical and geological study of quaternary deposits and weathering profiles

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Gi Young; Lee, Bong Ho [Andong National Univ., Andong (Korea, Republic of)

    2004-01-15

    Movement history of a quaternary reverse fault cutting marine terrace deposit and tertiary bentonite in the Yangnammyon, Gyoungju city was studied by the mineralogical and microtextural analysis of the fault clays and weathered terrace deposits. Two types of fault clays were identified as greenish gray before the deposition of the marine terrace deposits and reddish brown after deposition. Greenish gray fault clay is composed mostly of smectite probably powdered from bentonite showing at least two events of movement from microtextures. After the bentonite was covered by quaternary marine gravel deposits, the reverse fault was reactivated cutting marine gravel deposits to form open spaces along the fault plane which allowed the hydrological infiltration of soil particles and deposition of clays in deep subsurface. The reddish brown 'fault' clays enclosed the fragments of dark brown ultrafine varved clay, proving two events of faulting, and slicken sides bisecting reddish brown clays suggest another faulting event in the final stage. Mineralogical and microtextural analysis of the fault clay show total five events of faulting, which had not been recognized even by thorough conventional paleoseismological investigation using trench, highlighting the importance of microtextural and mineralogical analysis in paleoseismology.

  2. Late Quaternary stratigraphy and depositional history of the Long Island Sound basin

    Science.gov (United States)

    Lewis, Ralph S.; Stone, Janet R.

    1991-01-01

    The stratigraphy of Late Quaternary geologic units beneath Long Island Sound (LIS) is interpreted from 3,500 km of high-resolution, seismic-reflection profiles supplemented by vibracore data. Knowledge gained from onshore regional geologic studies and previous offshore investigations is also incorporated in these interpretations.

  3. Quaternary coastal geology of Pernambuco State

    International Nuclear Information System (INIS)

    Dominguez, J.M.L.; Silva Pinto Bittencourt, A.C. da; Andrade Nery Leao, Z.M. de; Azevedo, A.E.G. de

    1990-01-01

    This paper presents a geological map of Quaternary deposits occuring along the coast of the State of Pernambuco. These deposits comprise: 1. two sets of beach-ridge terraces of Pleistocene (120,000 years B.P.) and Holocene (5,000 years B.P.) age; 2. paleolagoonal deposits (5,140-6,030 years B.P.); 3. sandstone and coralgal reefs with ages spanning from 1,830 to 5,170 years B.P.; and 4, alluvial, freshwater swamp, and coralgal reefs with ages spanning from 1,830 to 5,170 years B.P.; and 4. alluvial, freshwater swamp, and mangrove swamp deposits of Holocene age. Eighteen new radiocarbon dates of paleolagoonal deposits, sandstone reefs, coral, coralline algae, and vermetid gastropod incrustations are also reported herein. (author)

  4. Quaternary ammonium promoted ultra selective and sensitive fluorescence detection of fluoride ion in water and living cells.

    Science.gov (United States)

    Li, Long; Ji, Yuzhuo; Tang, Xinjing

    2014-10-21

    Highly selective and sensitive fluorescent probes with a quaternary ammonium moiety have been rationally designed and developed for fast and sensitive fluorescence detection of fluoride ion (F(-) from NaF, not TBAF) in aqueous solution and living cells. With the sequestration effect of quaternary ammonium, the detection time was less than 2 min and the detection limit of fluoride ion was as low as 0.57 ppm that is among the lowest detection limits in aqueous solutions of many fluoride fluorescence probes in the literature.

  5. pH-controlled quaternary ammonium herbicides capture/release by carboxymethyl-β-cyclodextrin functionalized magnetic adsorbents: Mechanisms and application

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chang; Wang, Peng [Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing 100193 (China); Shen, Zhigang [Zhong Nong Fa Seed Industry Group Co. Ltd, Beijing 600313 (China); Liu, Xueke; Zhou, Zhiqiang [Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing 100193 (China); Liu, Donghui, E-mail: liudh@cau.edu.cn [Department of Applied Chemistry, China Agricultural University, No. 2 West Yuanmingyuan Road, Beijing 100193 (China)

    2015-12-11

    In our work, the pH-controlled magnetic solid phase extraction for the determination of paraquat and diquat was introduced firstly. Furthermore, to clarify the mechanism of carboxymethyl-β-cyclodextrin functionalized magnetic adsorbents, we studied the pH-responsive supramolecular interaction between carboxymethyl-β-cyclodextrin (CM-β-CD) and paraquat/diquat by ultraviolet–visible (UV–vis) spectroscopy and nuclear magnetic resonance (NMR) experiment, and the energy-minimized structures were also obtained. Then, the functional group CM-β-CD was modified on the surface of magnetic materials to synthesize the adsorbent. The Fourier transform infrared spectrum (FT-IR) results proved the successful modification of CM-β-CD. Thus, this absorbent was applied for the determination of paraquat and diquat in water. Under the optimal condition, limits of detection (LODs) of paraquat and diquat were 0.8 μg L{sup −1} and 0.9 μg L{sup −1}, relative standard deviations (RSD) and recoveries varied 0.7–4.6% and 86.5–106.6%, respectively. Good recoveries (70.2–100.0%) and low RSD (1.7–9.6%) were achieved in analyzing spiked water samples. Furthermore, with the capillary electrophoresis (CE) as the analyser, the whole analytical process did not need the attendance of organic solvents. - Highlights: • The carboxymethyl-β-cyclodextrin functionalized magnetic adsorbents were synthesized. • The adsorbents could capture or release quaternary ammonium herbicides by changing pH. • The adsorbents were applied in the analysis of real water samples. • There is no attendance of organic solvents in the whole analysis process.

  6. Late Quaternary changes in climate

    Energy Technology Data Exchange (ETDEWEB)

    Holmgren, K; Karlen, W [Stockholm Univ. (Sweden). Dept. of Physical Geography

    1998-12-01

    This review concerns the Quaternary climate with an emphasis on the last 200 000 years. The present state of art in this field is described and evaluated. The review builds on a thorough examination of classic and recent literature. General as well as detailed patterns in climate are described and the forcing factors and feed-back effects are discussed. Changes in climate occur on all time-scales. During more than 90% of the Quaternary period earth has experienced vast ice sheets, i.e. glaciations have been more normal for the period than the warm interglacial conditions we face today. Major changes in climate, such as the 100 000 years glacial/interglacial cycle, are forced by the Milankovitch three astronomical cycles. Because the cycles have different length climate changes on earth do not follow a simple pattern and it is not possible to find perfect analogues of a certain period in the geological record. Recent discoveries include the observation that major changes in climate seem to occur at the same time on both hemispheres, although the astronomical theory implies a time-lag between latitudes. This probably reflects the influence of feed-back effects within the climate system. Another recent finding of importance is the rapid fluctuations that seem to be a normal process. When earth warmed after the last glaciation temperature jumps of up to 10 deg C occurred within less than a decade and precipitation more than doubled within the same time. The forcing factors behind these rapid fluctuations are not well understood but are believed to be a result of major re-organisations in the oceanic circulation. Realizing that nature, on its own, can cause rapid climate changes of this magnitude put some perspective on the anthropogenic global warming debate, where it is believed that the release of greenhouse gases will result in a global warming of a few C. To understand the forcing behind natural rapid climate changes appears as important as to understand the role

  7. Late Quaternary changes in climate

    International Nuclear Information System (INIS)

    Holmgren, K.; Karlen, W.

    1998-12-01

    This review concerns the Quaternary climate with an emphasis on the last 200 000 years. The present state of art in this field is described and evaluated. The review builds on a thorough examination of classic and recent literature. General as well as detailed patterns in climate are described and the forcing factors and feed-back effects are discussed. Changes in climate occur on all time-scales. During more than 90% of the Quaternary period earth has experienced vast ice sheets, i.e. glaciations have been more normal for the period than the warm interglacial conditions we face today. Major changes in climate, such as the 100 000 years glacial/interglacial cycle, are forced by the Milankovitch three astronomical cycles. Because the cycles have different length climate changes on earth do not follow a simple pattern and it is not possible to find perfect analogues of a certain period in the geological record. Recent discoveries include the observation that major changes in climate seem to occur at the same time on both hemispheres, although the astronomical theory implies a time-lag between latitudes. This probably reflects the influence of feed-back effects within the climate system. Another recent finding of importance is the rapid fluctuations that seem to be a normal process. When earth warmed after the last glaciation temperature jumps of up to 10 deg C occurred within less than a decade and precipitation more than doubled within the same time. The forcing factors behind these rapid fluctuations are not well understood but are believed to be a result of major re-organisations in the oceanic circulation. Realizing that nature, on its own, can cause rapid climate changes of this magnitude put some perspective on the anthropogenic global warming debate, where it is believed that the release of greenhouse gases will result in a global warming of a few C. To understand the forcing behind natural rapid climate changes appears as important as to understand the role

  8. Electrochemical studies on electroless ternary and quaternary Ni-P based alloys

    International Nuclear Information System (INIS)

    Balaraju, J.N.; Selvi, V. Ezhil; Grips, V.K. William; Rajam, K.S.

    2006-01-01

    The autocatalytic (electroless) deposition of Ni-P based alloys is a well-known commercial process that has found numerous applications because of their excellent anticorrosive, wear, magnetic, solderable properties, etc. It is a barrier coating, protecting the substrate by sealing it off from the corrosive environments, rather than by sacrificial action. The corrosion resistance varies with the phosphorus content of the deposit: relatively high for a high-phosphorus electroless nickel deposit but low for a low-phosphorus electroless nickel deposit. In the present investigation ternary Ni-W-P alloy films were prepared using alkaline citrate-based bath. Quaternary Ni-W-Cu-P films were deposited by the addition of 3 mM copper ions in ternary Ni-W-P bath. X-ray diffraction (XRD) studies indicated that all the deposits were nanocrystalline, i.e. 1.2, 2.1 and 6.0 nm, respectively, for binary, ternary and quaternary alloys. Corrosion resistance of the films was evaluated in 3.5% sodium chloride solution in non-deaerated and deaerated conditions by potentiodynamic polarization and electrochemical impedance (EIS) methods. Lower corrosion current density values were obtained for the coatings tested in deaerated condition. EIS studies showed that higher charge transfer resistance values were obtained for binary Ni-P coatings compared to ternary or quaternary coatings. For all the coatings a gradual increase in the anodic current density had been observed beyond 740 mV. In deaerated condition all the reported coatings exhibited a narrow passive region and all the values of E p , E tp and i pass were very close showing no major changes in the electrochemical behavior. In the non-deaerated conditions no passivation behavior had been observed for all these coatings

  9. Development of antibacterial quaternary ammonium silane coatings on polyurethane catheters

    Czech Academy of Sciences Publication Activity Database

    Zanini, S.; Polissi, A.; Maccagni, E.A.; Dell'Orto, E.C.; Liberatore, Chiara; Riccardi, C.

    2015-01-01

    Roč. 451, Aug (2015), 78-84 ISSN 0021-9797 R&D Projects: GA MŠk EE2.3.20.0143 Grant - others:OP VK 6(XE) CZ.1.07/2.3.00/20.0143 Institutional support: RVO:68378271 Keywords : plasma-induced graft-polymerization * acrylic acid * ATR/FTIR * AFM * quaternary ammonium silane * Escherichia coli Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.782, year: 2015

  10. Polarization encoded all-optical quaternary successor with the help of SOA assisted Sagnac switch

    Science.gov (United States)

    Chattopadhyay, Tanay; Roy, Jitendra Nath

    2011-06-01

    The application of multi-valued (non-binary) signals can provide a considerable relief in transmission, storage and processing of large amount of information in digital signal processing. Optical multi-valued logical operation is an interesting challenge for future optical signal processing where we can expect much innovation. A novel all-optical quaternary successor (QSUC) circuit with the help of semiconductor optical amplifier (SOA)-assisted Sagnac switch is proposed and described. This circuit exploits the polarization properties of light. Different logical states are represented by different polarization state of light. Simulation result confirming described method is given in this paper. Proposed all-optical successor circuit can take an important and significant role in designing of all-optical quaternary universal inverter and modulo arithmetic unit (addition and multiplication).

  11. Quaternary ammonium isobaric tag for a relative and absolute quantification of peptides.

    Science.gov (United States)

    Setner, Bartosz; Stefanowicz, Piotr; Szewczuk, Zbigniew

    2018-02-01

    Isobaric labeling quantification of peptides has become a method of choice for mass spectrometry-based proteomics studies. However, despite of wide variety of commercially available isobaric tags, none of the currently available methods offers significant improvement of sensitivity of detection during MS experiment. Recently, many strategies were applied to increase the ionization efficiency of peptides involving chemical modifications introducing quaternary ammonium fixed charge. Here, we present a novel quaternary ammonium-based isobaric tag for relative and absolute quantification of peptides (QAS-iTRAQ 2-plex). Upon collisional activation, the new stable benzylic-type cationic reporter ion is liberated from the tag. Deuterium atoms were used to offset the differential masses of a reporter group. We tested the applicability of QAS-iTRAQ 2-plex reagent on a series of model peptides as well as bovine serum albumin tryptic digest. Obtained results suggest usefulness of this isobaric ionization tag for relative and absolute quantification of peptides. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Planktonic foraminifera from a quaternary deep sea core from the southern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Naidu, P.D.; Rao, P.S.; Pattan, J.N.

    An investigation on planktonic foraminifera and calcium carbonate content of a box core collected at a depth of 2556 m from the southern part of the Arabian sea indicates faunal changes depicting Quaternary climatic fluctuations. Based on the study...

  13. Uplift of quaternary shorelines in eastern Patagonia: Darwin revisited

    Science.gov (United States)

    Pedoja, Kevin; Regard, Vincent; Husson, Laurent; Martinod, Joseph; Guillaume, Benjamin; Fucks, Enrique; Iglesias, Maximiliano; Weill, Pierre

    2011-04-01

    During his journey on the Beagle, Darwin observed the uniformity in the elevation of coastal Eastern Patagonia along more than 2000 km. More than one century later, the sequences of Quaternary shorelines of eastern Patagonia have been described and their deposits dated but not yet interpreted in terms of geodynamics. Consequently, we i) mapped the repartition of the Quaternary coastal sequences in Argentinean Patagonia, ii) secured accurate altitudes of shoreline angles associated with erosional morphologies (i.e. marine terraces and notches), iii) took into account previous chrono-stratigraphical interpretations in order to calculate mean uplift rates since ~ 440 ka (MIS 11) and proposed age ranges for the higher and older features (up to ~ 180 m), and iv) focused on the Last Interglacial Maximum terrace (MIS 5e) as the best constrained marine terrace (in terms of age and altitude) in order to use it as a tectonic benchmark to quantify uplift rates along the entire passive margin of Eastern South America. Our results show that the eastern Patagonia uplift is constant through time and twice the uplift of the rest of the South American margin. We suggest that the enhanced uplift along the eastern Patagonian coast that interested Darwin during his journey around South America on the Beagle could originate from the subduction of the Chile ridge and the associated dynamic uplift.

  14. Design of quaternary logic circuit using quantum dot gate-quantum dot channel FET (QDG-QDCFET)

    Science.gov (United States)

    Karmakar, Supriya

    2014-10-01

    This paper presents the implementation of quaternary logic circuits based on quantum dot gate-quantum dot channel field effect transistor (QDG-QDCFET). The super lattice structure in the quantum dot channel region of QDG-QDCFET and the electron tunnelling from inversion channel to the quantum dot layer in the gate region of a QDG-QDCFET change the threshold voltage of this device which produces two intermediate states between its ON and OFF states. This property of QDG-QDCFET is used to implement multi-valued logic for future multi-valued logic circuit. This paper presents the design of basic quaternary logic operation such as inverter, AND and OR operation based on QDG-QDCFET.

  15. Kinematics of the quaternary fault zones in the Kyeongju area of the southeastern Korean Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Seob; Lee, Byeong Hyui; Kwon, Hyeok Sang [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)] (and others)

    1998-09-15

    The purposes of this study are to interpret the kinematics of the Quaternary fault zones in the Kyeongju area, to determine deformation mechanisms during faulting by analyzing micorstrucutres of fault rocks from the fault zones, and to unravel the technic evaluation of the regional fault structures in the Kyeongju-Wolsung area. The scope of this study consists of ; collection and interpretation of structural elements through a detailed geologic investigation on the Quaternary faults in the Kyeongju-Wolsung area, interpretation of fault-rock microstructures from the fault zones using oriented samples of faults rocks, determination of deformation processes and mechanisms of the fault rocks and, interpretation of faulting kinematics and evaluation of the fault zones.

  16. Kinematics of the quaternary fault zones in the Kyeongju area of the southeastern Korean Peninsula

    International Nuclear Information System (INIS)

    Kim, In Seob; Lee, Byeong Hyui; Kwon, Hyeok Sang

    1998-09-01

    The purposes of this study are to interpret the kinematics of the Quaternary fault zones in the Kyeongju area, to determine deformation mechanisms during faulting by analyzing micorstrucutres of fault rocks from the fault zones, and to unravel the technic evaluation of the regional fault structures in the Kyeongju-Wolsung area. The scope of this study consists of ; collection and interpretation of structural elements through a detailed geologic investigation on the Quaternary faults in the Kyeongju-Wolsung area, interpretation of fault-rock microstructures from the fault zones using oriented samples of faults rocks, determination of deformation processes and mechanisms of the fault rocks and, interpretation of faulting kinematics and evaluation of the fault zones

  17. Theoretical study of quaternary compounds as thin-film solar cell absorber

    International Nuclear Information System (INIS)

    Su, Huai Wei

    2010-01-01

    Full text : Design of chalcogenide photovoltaic absorbers is carried out systematically through sequential cation mutation, from binary to ternary to quaternary compounds, using first-principles electronic structure calculations. Several universal trends are found for the ternary and two classes of quaternary chalcogenides. For example, the lowest-energy structure always has larger lattice constant a, smaller tetragonal distortion parameter η=c/2a, and larger band gap than the metastable structures for common-row cation mutations. The band gap is reduced during the mutation. The band gap decreases from binary II-VI to ternary I-III-VI 2 are mostly due to the p-d repulsion in the valence band, the decreases from ternary I-III-VI 2 to quaternary I 2 -II-IV-VI 4 chalcogenides are due to the downshift in the conduction band caused by the wavefunction localization on the group IV cation site. It was found that I 2 -II-IV-VI 4 compounds are more stable in the kesterite structure, whereas the widely-assumed stannite structure reported in the literature is most likely due to partial disorder in the I-II layer of the kesterite phase. Among the derived quaternary compounds, Cu 2 ZnSnS 4 (CZTS) is one of the ideal candidate absorber materials for thin-film solar cells with an optimal band gap, high absorption coefficient, abundant elemental components, and is adaptable to various growth techniques. It was performed a series of first-principles electronic structure calculations for CZTS. Also it was found that in the ground state kesterite structure, (i) the chemical potential region that CZTS can form is very small. Therefore, it will be very difficult to obtain high quality stoichiometric CZTS samples; (ii) The dominant p-type acceptor in CZTS is CuZn, however, the associated acceptor level is relatively high, suggesting that p-type doping in CZTS is more difficult than ternary compounds such as CuInSe 2 ; (iii) The formation of the self-compensated defect pair [Cu

  18. Antitumor activity of newly synthesized oxo and ethylidene derivatives of bile acids and their amides and oxazolines.

    Science.gov (United States)

    Bjedov, Srđan; Jakimov, Dimitar; Pilipović, Ana; Poša, Mihalj; Sakač, Marija

    2017-04-01

    Bile acid derivatives with modifications in side chain and modifications on steroid skeleton were synthetized and their antitumor activity against five human cancer cell lines was investigated. Modifications in side chain include amid group, formed in reaction with 2-amino-2-methylpropanol, and 4,4-dimethyloxazoline group, obtained after cyclization of amides. In the steroid skeleton oxo groups were introduced in position 7 (2, 2a, 2b) and 7,12 (3, 3a, 3b). Ethylidene groups were introduced regio- and stereoselectively on C-7, and/or without stereoselectivity on C-3 by Wittig reaction. By combination of these modifications, a series of 19 bile acid derivatives were synthesized. Compounds containing both C-7 ethylidene and C-12 carbonyl groups (6, 6a, 6b) shown very good antitumor activity with IC 50 amide or oxazoline group has positive effect on cytotoxicity. Different molecular descriptors were determined in silico and after principal component analysis was found that molecular descriptor BLTF96 can be used for fast assessment of experimental cytotoxicity of bile acid derivatives. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Determination of quaternary ammonium compounds by potentiometric titration with an ionic surfactant electrode: single-laboratory validation.

    Science.gov (United States)

    Price, Randi; Wan, Ping

    2010-01-01

    A potentiometric titration for determining the quaternary ammonium compounds (QAC) commonly found in antimicrobial products was validated by a single laboratory. Traditionally, QACs were determined by using a biphasic (chloroform and water) manual titration procedure. Because of safety considerations regarding chloroform, as well as the subjectivity of color indicator-based manual titration determinations, an automatic potentiometric titration procedure was tested with quaternary nitrogen product formulations. By using the Metrohm Titrando system coupled with an ionic surfactant electrode and an Ag/AgCl reference electrode, titrations were performed with various QAC-containing formulation products/matrixes; a standard sodium lauryl sulfate solution was used as the titrant. Results for the products tested are sufficiently reproducible and accurate for the purpose of regulatory product enforcement. The robustness of the method was measured by varying pH levels, as well as by comparing buffered versus unbuffered titration systems. A quantitation range of 1-1000 ppm quaternary nitrogen was established. Eight commercially available antimicrobial products covering a variety of matrixes were assayed; the results obtained were comparable to those obtained by the manual titration method. Recoveries of 94 to 104% were obtained for spiked samples.

  20. A Quaternary Geomagnetic Instability Time Scale

    Science.gov (United States)

    Singer, B. S.

    2013-12-01

    Reversals and excursions of Earth's geomagnetic field create marker horizons that are readily detected in sedimentary and volcanic rocks worldwide. An accurate and precise chronology of these geomagnetic field instabilities is fundamental to understanding several aspects of Quaternary climate, dynamo processes, and surface processes. For example, stratigraphic correlation between marine sediment and polar ice records of climate change across the cryospheres benefits from a highly resolved record of reversals and excursions. The temporal patterns of dynamo behavior may reflect physical interactions between the molten outer core and the solid inner core or lowermost mantle. These interactions may control reversal frequency and shape the weak magnetic fields that arise during successive dynamo instabilities. Moreover, weakening of the axial dipole during reversals and excursions enhances the production of cosmogenic isotopes that are used in sediment and ice core stratigraphy and surface exposure dating. The Geomagnetic Instability Time Scale (GITS) is based on the direct dating of transitional polarity states recorded by lava flows using the 40Ar/39Ar method, in parallel with astrochronologic age models of marine sediments in which O isotope and magnetic records have been obtained. A review of data from Quaternary lava flows and sediments yields a GITS comprising 10 polarity reversals and 27 excursions during the past 2.6 million years. Nine of the ten reversals bounding chrons and subchrons are associated with 40Ar/39Ar ages of transitionally-magnetized lava flows. The tenth, the Guass-Matuyama chron boundary, is tightly bracketed by 40Ar/39Ar dated ash deposits. Of the 27 well-documented excursions, 14 occurred during the Matuyama chron and 13 during the Brunhes chron; 19 have been dated directly using the 40Ar/39Ar method on transitionally-magnetized volcanic rocks and form the backbone of the GITS. Excursions are clearly not the rare phenomena once thought

  1. Geomorphic evidence for enhanced Pliocene-Quaternary faulting in the northwestern Basin and Range

    Science.gov (United States)

    Ellis, Magdalena A; Barnes Jason B,; Colgan, Joseph P.

    2014-01-01

    Mountains in the U.S. Basin and Range Province are similar in form, yet they have different histories of deformation and uplift. Unfortunately, chronicling fault slip with techniques like thermochronology and geodetics can still leave sizable, yet potentially important gaps at Pliocene–Quaternary (∼105–106 yr) time scales. Here, we combine existing geochronology with new geomorphic observations and approaches to investigate the Miocene to Quaternary slip history of active normal faults that are exhuming three footwall ranges in northwestern Nevada: the Pine Forest Range, the Jackson Mountains, and the Santa Rosa Range. We use the National Elevation Dataset (10 m) digital elevation model (DEM) to measure bedrock river profiles and hillslope gradients from these ranges. We observe a prominent suite of channel convexities (knickpoints) that segment the channels into upper reaches with low steepness (mean ksn = ∼182; θref = 0.51) and lower, fault-proximal reaches with high steepness (mean ksn = ∼361), with a concomitant increase in hillslope angles of ∼6°–9°. Geologic maps and field-based proxies for rock strength allow us to rule out static causes for the knickpoints and interpret them as transient features triggered by a drop in base level that created ∼20% of the existing relief (∼220 m of ∼1050 m total). We then constrain the timing of base-level change using paleochannel profile reconstructions, catchment-scale volumetric erosion fluxes, and a stream-power–based knickpoint celerity (migration) model. Low-temperature thermochronology data show that faulting began at ca. 11–12 Ma, yet our results estimate knickpoint initiation began in the last 5 Ma and possibly as recently as 0.1 Ma with reasonable migration rates of 0.5–2 mm/yr. We interpret the collective results to be evidence for enhanced Pliocene–Quaternary fault slip that may be related to tectonic reorganization in the American West, although we cannot rule out climate as a

  2. Preliminary maps of Quaternary deposits and liquefaction susceptibility, nine-county San Francisco Bay region, California: a digital database

    Science.gov (United States)

    Knudsen, Keith L.; Sowers, Janet M.; Witter, Robert C.; Wentworth, Carl M.; Helley, Edward J.; Nicholson, Robert S.; Wright, Heather M.; Brown, Katherine H.

    2000-01-01

    This report presents a preliminary map and database of Quaternary deposits and liquefaction susceptibility for the nine-county San Francisco Bay region, together with a digital compendium of ground effects associated with past earthquakes in the region. The report consists of (1) a spatial database of fivedata layers (Quaternary deposits, quadrangle index, and three ground effects layers) and two text layers (a labels and leaders layer for Quaternary deposits and for ground effects), (2) two small-scale colored maps (Quaternary deposits and liquefaction susceptibility), (3) a text describing the Quaternary map, liquefaction interpretation, and the ground effects compendium, and (4) the databse description pamphlet. The nine counties surrounding San Francisco Bay straddle the San Andreas fault system, which exposes the region to serious earthquake hazard (Working Group on California Earthquake Probabilities, 1999). Much of the land adjacent to the Bay and the major rivers and streams is underlain by unconsolidated deposits that are particularly vulnerable to earthquake shaking and liquefaction of water-saturated granular sediment. This new map provides a modern and regionally consistent treatment of Quaternary surficial deposits that builds on the pioneering mapping of Helley and Lajoie (Helley and others, 1979) and such intervening work as Atwater (1982), Helley and others (1994), and Helley and Graymer (1997a and b). Like these earlier studies, the current mapping uses geomorphic expression, pedogenic soils, and inferred depositional environments to define and distinguish the map units. In contrast to the twelve map units of Helley and Lajoie, however, this new map uses a complex stratigraphy of some forty units, which permits a more realistic portrayal of the Quaternary depositional system. The two colored maps provide a regional summary of the new mapping at a scale of 1:275,000, a scale that is sufficient to show the general distribution and relationships of

  3. Nano-Architecture of nitrogen-doped graphene films synthesized from a solid CN source.

    Science.gov (United States)

    Maddi, Chiranjeevi; Bourquard, Florent; Barnier, Vincent; Avila, José; Asensio, Maria-Carmen; Tite, Teddy; Donnet, Christophe; Garrelie, Florence

    2018-02-19

    New synthesis routes to tailor graphene properties by controlling the concentration and chemical configuration of dopants show great promise. Herein we report the direct reproducible synthesis of 2-3% nitrogen-doped 'few-layer' graphene from a solid state nitrogen carbide a-C:N source synthesized by femtosecond pulsed laser ablation. Analytical investigations, including synchrotron facilities, made it possible to identify the configuration and chemistry of the nitrogen-doped graphene films. Auger mapping successfully quantified the 2D distribution of the number of graphene layers over the surface, and hence offers a new original way to probe the architecture of graphene sheets. The films mainly consist in a Bernal ABA stacking three-layer architecture, with a layer number distribution ranging from 2 to 6. Nitrogen doping affects the charge carrier distribution but has no significant effects on the number of lattice defects or disorders, compared to undoped graphene synthetized in similar conditions. Pyridinic, quaternary and pyrrolic nitrogen are the dominant chemical configurations, pyridinic N being preponderant at the scale of the film architecture. This work opens highly promising perspectives for the development of self-organized nitrogen-doped graphene materials, as synthetized from solid carbon nitride, with various functionalities, and for the characterization of 2D materials using a significant new methodology.

  4. Newly Homeless Youth Typically Return Home

    OpenAIRE

    Milburn, Norweeta G.; Rosenthal, Doreen; Rotheram-Borus, Mary Jane; Mallett, Shelley; Batterham, Philip; Rice, Eric; Solorio, Rosa

    2007-01-01

    165 newly homeless adolescents from Melbourne, Australia and 261 from Los Angeles, United States were surveyed and followed for two years. Most newly homeless adolescents returned home (70% U.S., 47% Australia) for significant amounts of time (39% U.S., 17% Australia more than 12 months) within two years of becoming homeless.

  5. Synoptic climate change as a driver of late Quaternary glaciations in the mid-latitudes of the Southern Hemisphere

    Science.gov (United States)

    Rother, H.; Shulmeister, J.

    2006-05-01

    The relative timing of late Quaternary glacial advances in mid-latitude (40-55° S) mountain belts of the Southern Hemisphere (SH) has become a critical focus in the debate on global climate teleconnections. On the basis of glacial data from New Zealand (NZ) and southern South America it has been argued that interhemispheric synchrony or asynchrony of Quaternary glacial events is due to Northern Hemisphere (NH) forcing of SH climate through either the ocean or atmosphere systems. Here we present a glacial snow-mass balance model that demonstrates that large scale glaciation in the temperate and hyperhumid Southern Alps of New Zealand can be generated with moderate cooling. This is because the rapid conversion of precipitation from rainfall to snowfall drives massive ice accumulation at small thermal changes (1-4°C). Our model is consistent with recent paleo-environmental reconstructions showing that glacial advances in New Zealand during the Last Glacial Maximum (LGM) and the Last Glacial Interglacial Transition (LGIT) occurred under very moderate cooling. We suggest that such moderate cooling could be generated by changes in synoptic climatology, specifically through enhanced regional flow of moist westerly air masses. Our results imply that NH climate forcing may not have been the exclusive driver of Quaternary glaciations in New Zealand and that synoptic style climate variations are a better explanation for at least some late Quaternary glacial events, in particular during the LGIT (e.g. Younger Dryas and/or Antarctic Cold Reversal).

  6. Synoptic climate change as a driver of late Quaternary glaciations in the mid-latitudes of the Southern Hemisphere

    Directory of Open Access Journals (Sweden)

    H. Rother

    2006-01-01

    Full Text Available The relative timing of late Quaternary glacial advances in mid-latitude (40-55° S mountain belts of the Southern Hemisphere (SH has become a critical focus in the debate on global climate teleconnections. On the basis of glacial data from New Zealand (NZ and southern South America it has been argued that interhemispheric synchrony or asynchrony of Quaternary glacial events is due to Northern Hemisphere (NH forcing of SH climate through either the ocean or atmosphere systems. Here we present a glacial snow-mass balance model that demonstrates that large scale glaciation in the temperate and hyperhumid Southern Alps of New Zealand can be generated with moderate cooling. This is because the rapid conversion of precipitation from rainfall to snowfall drives massive ice accumulation at small thermal changes (1-4°C. Our model is consistent with recent paleo-environmental reconstructions showing that glacial advances in New Zealand during the Last Glacial Maximum (LGM and the Last Glacial Interglacial Transition (LGIT occurred under very moderate cooling. We suggest that such moderate cooling could be generated by changes in synoptic climatology, specifically through enhanced regional flow of moist westerly air masses. Our results imply that NH climate forcing may not have been the exclusive driver of Quaternary glaciations in New Zealand and that synoptic style climate variations are a better explanation for at least some late Quaternary glacial events, in particular during the LGIT (e.g. Younger Dryas and/or Antarctic Cold Reversal.

  7. Late Quaternary extinctions: The promise of TAMS 14C dating

    International Nuclear Information System (INIS)

    Martin, P.S.

    1987-01-01

    In the last 30 000 years late Quaternary extinctions eliminated over two-thirds of the large land mammals of America and Australia and most of the endemic land vertebrates on oceanic islands. Specimens of extinct animals yielding too little organic material for measurement in decay counters are suitable for TAMS dating. Initial results support older evidence of an extinction chronology that was catastrophic regionally, transgressive globally, and linked to the spread of prehistoric people. (orig.)

  8. Effects of two newly synthesized analogues of lidocaine on rat arterial blood pressure and heart rate.

    Science.gov (United States)

    Al Rasheed, N M; Al Sayed, M I; Al Zuhair, H H; Al Obaid, A R; Fatani, A J

    2001-04-01

    Two new analogues of lidocaine were synthesized at the College of Pharmacy, King Saud University: compound I (Methyl-2-[2-(N,N-diethylamino) acetamido]-3-cyano-4,5-dimethylbenzoate) and compound II (Methyl-2-[2-(piperidino) acetamido]-3-cyano-4,5-dimethylbenzoate). Their influence on the arterial blood pressure and the heart rate of urethane-anaesthetized rats was studied and compared with the actions of lidocaine. Compounds I, II and lidocaine induced significant dose-dependent decreases in the arterial blood pressure and heart rate, which usually returned to basal values within 3-5 min. There were significant differences in the potency of the three compounds in producing their effects on blood pressure and heart rate (Plidocaine and compound I, respectively. The results of this study also indicated the ineffectiveness of antagonists of autonomic, histaminergic and 5-HT receptor, and various vasodilators in blocking the actions of the three compounds on blood pressure and heart rate. Pretreatment with CaCl(2)significantly reduced the hypotension and bradycardia induced by the three compounds, suggesting the involvement of calcium channels, probably of the L type. Several possible mechanisms are postulated. In conclusion, the results direct attention to the capability of the two new compounds to decrease blood pressure and heart rate; affects that may have clinical potential. Copyright 2001 Academic Press.

  9. Syntheses and characterization of one-dimensional alkali metal antimony(III) thiostannates(IV), A{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} (A=K, Rb, Cs)

    Energy Technology Data Exchange (ETDEWEB)

    Yohannan, Jinu P.; Vidyasagar, Kanamaluru, E-mail: kvsagar@iitm.ac.in

    2015-01-15

    Three new isostructural quaternary antimony(III) thiostannates(IV), A{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} (A=K, Rb, Cs) have been synthesized by using alkali metal thiosulfate flux and structurally characterized by X-ray diffraction. Their structures contain A{sup +} ions around the [Sb{sub 2}Sn{sub 3}S{sub 10}]{sup 2−} chains, which are built from SbS{sub 3} pyramids, SnS{sub 6} octahedra and SnS{sub 4} tetrahedra. Raman and Mössbauer spectroscopic measurements corroborate the oxidation states and coordination environments of Sb(III) and Sn(IV). All three compounds are wide band gap semiconductors. Potassium compound undergoes partial exchange with strontium, cadmium and lead ions. - Graphical abstract: Syntheses, crystal structure, spectroscopic and partial ion-exchange studies of new one-dimensional alkali metal antimony(III) thiostannates(IV), A{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} (A=K, Rb, Cs) are described. - Highlights: • Syntheses of new alkali metal antimony(III) thiostannates(IV), A{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} (A=K, Rb, Cs). • Wide band gap semiconductors with one-dimensional structure. • Topotactic partial exchange of K{sup +} ions of K{sub 2}Sb{sub 2}Sn{sub 3}S{sub 10} with Sr{sup 2+}, Cd{sup 2+} and Pb{sup 2+} ions.

  10. Electrical imaging and self-potential survayes to study the geological setting of the Quaternary, slope depositsin the Agri high valley (Southern Italy

    Directory of Open Access Journals (Sweden)

    M. Schiattarella

    2000-06-01

    Full Text Available We present the results of a geophysical survey carried out to outline the structural modelling of Quaternary slopedeposits in the northern part of the Agri high valley (Basilicata, Southern Italy. Quaternary folding and brittle deformations of the subaerial slope deposits have been studied combining electrical imaging and self-potential surveys with geological structural analysis. This integrated approach indicates that the area underwent both transpressional and transtensional tectonics during Pleistocene times as testified by the existence of a push up structure in the basement buried by deformed Quaternary breccias. On this basis, the valley appears to be a more complex structure than a simple extensional graben, as traditionally assumed in the literature.

  11. Global late Quaternary megafauna extinctions linked to humans, not climate change.

    Science.gov (United States)

    Sandom, Christopher; Faurby, Søren; Sandel, Brody; Svenning, Jens-Christian

    2014-07-22

    The late Quaternary megafauna extinction was a severe global-scale event. Two factors, climate change and modern humans, have received broad support as the primary drivers, but their absolute and relative importance remains controversial. To date, focus has been on the extinction chronology of individual or small groups of species, specific geographical regions or macroscale studies at very coarse geographical and taxonomic resolution, limiting the possibility of adequately testing the proposed hypotheses. We present, to our knowledge, the first global analysis of this extinction based on comprehensive country-level data on the geographical distribution of all large mammal species (more than or equal to 10 kg) that have gone globally or continentally extinct between the beginning of the Last Interglacial at 132,000 years BP and the late Holocene 1000 years BP, testing the relative roles played by glacial-interglacial climate change and humans. We show that the severity of extinction is strongly tied to hominin palaeobiogeography, with at most a weak, Eurasia-specific link to climate change. This first species-level macroscale analysis at relatively high geographical resolution provides strong support for modern humans as the primary driver of the worldwide megafauna losses during the late Quaternary.

  12. Forms of Knowledge Incorporated in Clinical Decision-making among Newly-Graduated Nurses: A Metasynthesis

    DEFF Research Database (Denmark)

    Voldbjerg, Siri; Elgaard Sørensen, Erik; Grønkjær, Mette

    2014-01-01

    Clinical-decision-making is of decisive importance to how evidence-based practice is put into practice. Schools of Nursing have a responsibility to teach and train nursing students to make clinical decisions within a frame of evidence-based practice. Clinical decision-making among nurses has been...... explored from numerous angles using a diversity of methodologies. Existing research has mainly focused on promoting and inhibiting factors for implementation of evidence-based practice and incorporation of research evidence in the clinical-decision. Little attention has been given to the nurses' behavior......, including the knowledge that actually informs the newly graduated nurses’ clinical decision. The aim of the study is to combine and synthesize results from qualitative research. Noblit and Hare’s meta-ethnographic approach is used to conduct a metasynthesis of qualitative research that has studied...

  13. The Tl{sub 2}S–PbS–SiS{sub 2} system and the crystal and electronic structure of quaternary chalcogenide Tl{sub 2}PbSiS{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Mozolyuk, M.Y.; Piskach, L.V. [Department of Inorganic and Physical Chemistry, Lesya Ukrainka Eastern European National University, 13 Voli Avenue, 43025, Lutsk (Ukraine); Fedorchuk, A.O. [Department of Inorganic and Organic Chemistry, Lviv National University of Veterinary Medicine and Biotechnologies, 50 Pekarska Street, 79010, Lviv (Ukraine); Olekseyuk, I.D.; Parasyuk, O.V. [Department of Inorganic and Physical Chemistry, Lesya Ukrainka Eastern European National University, 13 Voli Avenue, 43025, Lutsk (Ukraine); Khyzhun, O.Y., E-mail: khyzhun@ipms.kiev.ua [Frantsevych Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Krzhyzhanivsky Street, 03142, Kyiv (Ukraine)

    2017-07-01

    Chalcogenides of the quasi-ternary system Tl{sub 2}S–PbS–SiS{sub 2} were synthesized in the evacuated silica ampoules by the melting and annealing technique. Phase equilibria in the system was investigated by XRD method. Isothermal section of the system was studied, and two intermediate quaternary phases were discovered to exist (Tl{sub 2}PbSiS{sub 4}, ∼Tl{sub 2}PbSi{sub 3}S{sub 8}). The quasi-binary section Tl{sub 2}SiS{sub 3}–PbS was investigated by DTA. Its phase diagram was constructed, and it was established that the equimolar compound melts incongruently at 818 K. The crystal structure of the quaternary compound Tl{sub 2}PbSiS{sub 4} was determined by X-ray powder diffraction. It crystallizes in the monoclinic space group P2{sub 1}/a with the unit-cell parameters a = 8.8141(4), b = 9.0150(5), c = 10.4383(5) Å, and β = 94.490(4)° (Tl{sub 2}PbGeS{sub 4} structure type). Reliability factors calculated in the isotropic approximation were found to be R{sub I} = 0.0564 and R{sub P} = 0.1070. The Tl{sub 2}PbSiS{sub 4} single crystal was tested with X-ray photoelectron spectroscopy. In particular, the XPS core-level and valence-band spectra were recorded for pristine and Ar{sup +}-ion bombarded surfaces of Tl{sub 2}PbSiS{sub 4}. The Tl{sub 2}PbSiS{sub 4} single crystal was found to be rather stable with respect to Ar{sup +}-ion irradiation. We have also measured the X-ray emission band depicting the energy distribution of mainly the S 3p states and compared it on a common energy scale with the XPS valence-band spectrum of the Tl{sub 2}PbSiS{sub 4} crystal. The above comparison indicates that the S 3p states contribute substantively in the upper portion of the valence band of Tl{sub 2}PbSiS{sub 4}, with their significant contributions in other portions of the valence-band region. - Highlights: • Chalcogenides of the quasi-ternary system Tl{sub 2}S–PbS–SiS{sub 2} were synthesized. • Two intermediate quaternary phases were discovered to exist (Tl

  14. Separation of rhodium(III and iridium(IV chlorido species by quaternary diammonium centres hosted on silica microparticles

    Directory of Open Access Journals (Sweden)

    A. Majavu

    2017-12-01

    Full Text Available Silica gel was functionalized with six different quaternary diammonium centres derived from ethylenediamine (EDA, tetramethylenediamine (TMDA, hexamethylenediamine (HMDA, 1,8-diaminooctane (OMDA, 1,10-diaminodecane (DMDA and 1,12-diaminododecane (DDMDA to produce Si-QUAT EDA, Si-QUAT TMDA, Si-QUAT HMDA, Si-QUAT OMDA, Si-QUAT DMDA and Si-QUAT DDMDA, respectively. The synthesized silica-based resins were characterized by means of FTIR, XPS, SEM, BET surface area, thermogravimetric analysis and elemental analysis. The materials were used to investigate the adsorption and separation of [RhCl5(H2O]2− and [IrCl6]2−. Batch studies (equilibrium and kinetic studies were conducted to study the adsorption of [RhCl5(H2O]2− and [IrCl6]2− onto Si-QUAT EDA, Si-QUAT TMDA, Si-QUAT HMDA, Si-QUAT OMDA, Si-QUAT DMDA and Si-QUAT DDMDA using single metal aqueous solutions. The Freundlich isotherm confirmed multilayer adsorption and the Freundlich constant (kf displayed the following ascending order; Si-QUAT EDA, Si-QUAT TMDA, Si-QUAT HMDA, Si-QUAT OMDA and Si-QUAT DMDA, and a decrease in kf for Si-QUAT DDMDA. Kinetic studies suggest a pseudo-first order kinetic model. Column studies were also conducted for a binary mixture of these metal ion chlorido species ([RhCl5(H2O]2− and [IrCl6]2−. The iridium loading capacities increased as the carbon spacer between the diammonium centres increased in the following order; Si-QUAT EDA, Si-QUAT TMDA, Si-QUAT HMDA, Si-QUAT OMDA and Si-QUAT DMDA (4.56 mg/g, 6.88 mg/g, 14.63 mg/g, 19.01 mg/g and 29.35 mg/g, respectively. It was observed that the iridium loading capacity of Si-QUAT DDMDA decreased to 8.90 mg/g. This paper presents iridium-specific materials that could be applied in solutions of secondary PGMs sources containing rhodium and iridium as well as in feed solutions from ore processing. Keywords: Silica gel, Quaternary diammonium centres, Rhodium, Iridium, Separation

  15. Quaternary structure of the yeast pheromone receptor Ste2 in living cells.

    Science.gov (United States)

    Stoneman, Michael R; Paprocki, Joel D; Biener, Gabriel; Yokoi, Koki; Shevade, Aishwarya; Kuchin, Sergei; Raicu, Valerică

    2017-09-01

    Transmembrane proteins known as G protein-coupled receptors (GPCRs) have been shown to form functional homo- or hetero-oligomeric complexes, although agreement has been slow to emerge on whether homo-oligomerization plays functional roles. Here we introduce a platform to determine the identity and abundance of differing quaternary structures formed by GPCRs in living cells following changes in environmental conditions, such as changes in concentrations. The method capitalizes on the intrinsic capability of FRET spectrometry to extract oligomer geometrical information from distributions of FRET efficiencies (or FRET spectrograms) determined from pixel-level imaging of cells, combined with the ability of the statistical ensemble approaches to FRET to probe the proportion of different quaternary structures (such as dimers, rhombus or parallelogram shaped tetramers, etc.) from averages over entire cells. Our approach revealed that the yeast pheromone receptor Ste2 forms predominantly tetramers at average expression levels of 2 to 25 molecules per pixel (2.8·10 -6 to 3.5·10 -5 molecules/nm 2 ), and a mixture of tetramers and octamers at expression levels of 25-100 molecules per pixel (3.5·10 -5 to 1.4·10 -4 molecules/nm 2 ). Ste2 is a class D GPCR found in the yeast Saccharomyces cerevisiae of the mating type a, and binds the pheromone α-factor secreted by cells of the mating type α. Such investigations may inform development of antifungal therapies targeting oligomers of pheromone receptors. The proposed FRET imaging platform may be used to determine the quaternary structure sub-states and stoichiometry of any GPCR and, indeed, any membrane protein in living cells. This article is part of a Special Issue entitled: Interactions between membrane receptors in cellular membranes edited by Kalina Hristova. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Beyond BLASTing: Tertiary and Quaternary Structure Analysis Helps Identify Major Vault Proteins

    Science.gov (United States)

    Daly, Toni K.; Sutherland-Smith, Andrew J.; Penny, David

    2013-01-01

    We examine the advantages of going beyond sequence similarity and use both protein three-dimensional (3D) structure prediction and then quaternary structure (docking) of inferred 3D structures to help evaluate whether comparable sequences can fold into homologous structures with sufficient lateral associations for quaternary structure formation. Our test case is the major vault protein (MVP) that oligomerizes in multiple copies to form barrel-like vault particles and is relatively widespread among eukaryotes. We used the iterative threading assembly refinement server (I-TASSER) to predict whether putative MVP sequences identified by BLASTp and PSI Basic Local Alignment Search Tool are structurally similar to the experimentally determined rodent MVP tertiary structures. Then two identical predicted quaternary structures from I-TASSER are analyzed by RosettaDock to test whether a pair-wise association occurs, and hence whether the oligomeric vault complex is likely to form for a given MVP sequence. Positive controls for the method are the experimentally determined rat (Rattus norvegicus) vault X-ray crystal structure and the purple sea urchin (Strongylocentrotus purpuratus) MVP sequence that forms experimentally observed vaults. These and two kinetoplast MVP structural homologs were predicted with high confidence value, and RosettaDock predicted that these MVP sequences would dock laterally and therefore could form oligomeric vaults. As the negative control, I-TASSER did not predict an MVP-like structure from a randomized rat MVP sequence, even when constrained to the rat MVP crystal structure (PDB:2ZUO), thus further validating the method. The protocol identified six putative homologous MVP sequences in the heterobolosean Naegleria gruberi within the excavate kingdom. Two of these sequences are predicted to be structurally similar to rat MVP, despite being in excess of 300 residues shorter. The method can be used generally to help test predictions of homology via

  17. Quantitative analysis of deuterium using the isotopic effect on quaternary {sup 13}C NMR chemical shifts

    Energy Technology Data Exchange (ETDEWEB)

    Darwish, Tamim A., E-mail: tamim.darwish@ansto.gov.au [National Deuteration Facility, Australian Nuclear Science and Technology Organisation, Locked Bag 21, Kirrawee DC, NSW 2232 (Australia); Yepuri, Nageshwar Rao; Holden, Peter J. [National Deuteration Facility, Australian Nuclear Science and Technology Organisation, Locked Bag 21, Kirrawee DC, NSW 2232 (Australia); James, Michael [Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168 (Australia)

    2016-07-13

    Quantitative analysis of specifically deuterated compounds can be achieved by a number of conventional methods, such as mass spectroscopy, or by quantifying the residual {sup 1}H NMR signals compared to signals from internal standards. However, site specific quantification using these methods becomes challenging when dealing with non-specifically or randomly deuterated compounds that are produced by metal catalyzed hydrothermal reactions in D{sub 2}O, one of the most convenient deuteration methods. In this study, deuterium-induced NMR isotope shifts of quaternary {sup 13}C resonances neighboring deuterated sites have been utilized to quantify the degree of isotope labeling of molecular sites in non-specifically deuterated molecules. By probing {sup 13}C NMR signals while decoupling both proton and deuterium nuclei, it is possible to resolve {sup 13}C resonances of the different isotopologues based on the isotopic shifts and the degree of deuteration of the carbon atoms. We demonstrate that in different isotopologues, the same quaternary carbon, neighboring partially deuterated carbon atoms, are affected to an equal extent by relaxation. Decoupling both nuclei ({sup 1}H, {sup 2}H) resolves closely separated quaternary {sup 13}C signals of the different isotopologues, and allows their accurate integration and quantification under short relaxation delays (D1 = 1 s) and hence fast accumulative spectral acquisition. We have performed a number of approaches to quantify the deuterium content at different specific sites to demonstrate a convenient and generic analysis method for use in randomly deuterated molecules, or in cases of specifically deuterated molecules where back-exchange processes may take place during work up. - Graphical abstract: The relative intensities of quaternary {sup 13}C {"1H,"2H} resonances are equal despite the different relaxation delays, allowing the relative abundance of the different deuterated isotopologues to be calculated using NMR fast

  18. Mineralogy of auriferous deposits of the quaternary deposits in the San Luis Province, Argentina

    International Nuclear Information System (INIS)

    Karlsson, A.; Ayala, R. . E mail: Karlsson@arnet.com.ar

    2004-01-01

    The objective of this work is to study the mineralogy of the sands and clays of the quaternary deposits in the San Luis Mountain, Argentina. A series of algorithms applied to the sand fraction has permitted to determine sedimentary discontinuities. The two micron fraction of the sediments has been studied by a quantification technique based on X-ray diffraction by means of oriented preparations and run with copper tube. These quaternary silts have received fluvial lateral contributions. The high cristalinidad of non expandibles and fireclay clay show the antique of the silts. The polygenic processes have generated a great variety of clay mineral species like a large quantities of illite and in lesser extend kaolinite and smectites. The illite was probably generated by diagenetic changes. The high cristalinidad of non expandibles and fireclay clay show the antique of the silts [es

  19. Histological evaluation of tissue reactions to newly synthetized calcium silicate- and hydroxyapatite-based bioactive materials: in vivo study

    Directory of Open Access Journals (Sweden)

    Opačić-Galić Vanja

    2017-01-01

    Full Text Available Introduction/Objective. Development of materials which could be used as biological bone substitutes is one of the most valuable and active fields of biomaterial research. The goal of the study was to research the reaction of tissue on calcium silicate- (CS and hydroxyapatitebased (CS-HA newly synthesized nanomaterials, after being implanted into the subcutaneous tissue of a rats and direct pulp capping of rabbit teeth. Methods. The tested materials were implanted in 40 Wistar male rats, sacrificed after seven, 15, 30, and 60 days. The direct pulp capping was performed on the teeth of rabbits. Cavities were prepared on the vestibular surface of the incisors. The animals were sacrificed after 10 and 15 days. The control material was mineral trioxide aggregate (MTA. Histological analysis covered the tracking of inflammatory reaction cellular components, presence of gigantic cells, and necrosis of the tissue. Results. Seven days after the implantation, the strongest inflammatory response was given by the MTA (3.3 Ѓ} 0.48, while CS and CS-HA scored 3 ± 0.71. After 60 days, the rate of inflammatory reactions dropped, which was the least visible with CS-HA (0.2 ± 0.45. The least visible inflammatory reaction of the rabbits’ pulp tissue was spotted with the CS (1.83 ± 0.75, than with the MTA and CS-HA (2.67 ± 1.53, 3 ± 0.63. Conclusion. The newly synthesized materials caused a slight reaction of the subcutaneous tissue. CS-HA showed the best tissue tolerance. Nanostructural biomaterials caused a slight to moderate inflammatory reaction of the rabbits’ pulp tissue only in the immediate vicinity of the implanted material.

  20. Distribution and metabolism of quaternary amines in salt marshes

    Science.gov (United States)

    King, Gary M.

    1985-01-01

    Quaternary amines such as glycine betaine (GBT) are common osmotically active solutes in much of the marine biota. GBT is accumulated by various bacteria, algae, higher plants, invertebrates, and vertebrates in response to salinity or water stresses; in some species, GBT occurs at tens to hundreds of millimolar concentrations and can account for a significant fraction of total nitrogen. Initial studies suggest that GBT is readily converted to two potential methane precursors, trimethylamine (TMA) and acetate, in anoxic sediments. TMA is apparently the most important methane precursor in surface sediments containing sulfate reducing bacteria. In salt marshes, the bulk of the methane formed may be due to the metabolism of TMA rather than other substrates. Current research is focussed on testing this hypothesis and on determining the role of quaternary amino osmoregulatory solutes in methane fluxes from marine environments. Preliminary studies have dealt with several problems: (1) determination of GBT concentrations in the dominant flora and fauna of salt marshes; (2) synthesis of radiolabelled GBT for metabolic studies; and (3) determination of fates of BGT in marine sediments using radiotracers. Both GC and HPLC techniques have been used to assay GBT concentrations in plant and animal tissues. S. alterniflora is probably the only significant source of GBT (and indirectly of methane) since the biomass and distribution of most other species is limited. Current estimates suggest that S. alterniflora GBT could account for most of the methane efflux from salt marshes.

  1. Different virucidal activities of hyperbranched quaternary ammonium coatings on poliovirus and influenza virus

    NARCIS (Netherlands)

    Tuladhar, E.; Koning, de M.C.; Fundeanu, I.; Beumer, R.R.; Duizer, E.

    2012-01-01

    Virucidal activity of immobilized quaternary ammonium compounds (IQACs) coated onto glass and plastic surfaces was tested against enveloped influenza A (H1N1) virus and nonenveloped poliovirus Sabin1. The IQACs tested were virucidal against the influenza virus within 2 min, but no virucidal effect

  2. Lattice vibrations study of Ga1-xInxAsySb1-y quaternary alloys with low (In, As) content grown by liquid phase epitaxy

    International Nuclear Information System (INIS)

    Olvera-Herandez, J; Olvera-Cervantes, J; Rojas-Lopez, M; Navarro-Contreras, H; Vidal, M A; Anda, F de

    2006-01-01

    Raman scattering spectroscopy was used to measure and analyze the lattice vibrations in some quaternary Ga 1-x In x As y Sb 1-y alloys with low (In, As) contents (0.03 0 C. High Resolution X-Ray Diffraction results showed profiles associated with a quaternary layer lattice matched to the GaSb substrate as obtained from the (004) reflection. The experimental diffractograms were simulated to estimate alloy composition, thickness and lattice mismatch of the layer. Raman scattering results show phonon frequencies associated to the TO and LO GaAs-like modes as well as GaSb + InAs-like mode, which are characteristic of this quaternary alloy. The As content dependence of the phonon frequency measured in this alloy for low (In, As) contents agree well with the modified Random-Element Isodisplacement (REI) model and also with other available experimental reports. This method can also be used to estimate alloy compositions for this kind of quaternary alloys

  3. Tertiary and Quaternary sedimentation in a part of the Duero Basin Palencia, (Spain)

    NARCIS (Netherlands)

    Mabesoone, J.M.

    1959-01-01

    Sediments in the foreland of a mountain chain are sometimes suited to reconstitute the conditions in these mountains at the time of deposition of the sediments. The present study gives the results of a sedimentological investigation of the Tertiary and Quaternary deposits in a part of the Duero

  4. Hydration Structure of the Quaternary Ammonium Cations

    KAUST Repository

    Babiaczyk, Wojtek Iwo

    2010-11-25

    Two indicators of the hydropathicity of small solutes are introduced and tested by molecular dynamics simulations. These indicators are defined as probabilities of the orientation of water molecules\\' dipoles and hydrogen bond vectors, conditional on a generalized distance from the solute suitable for arbitrarily shaped molecules. Using conditional probabilities, it is possible to distinguish features of the distributions in close proximity of the solute. These regions contain the most significant information on the hydration structure but cannot be adequately represented by using, as is usually done, joint distance-angle probability densities. Our calculations show that using our indicators a relative hydropathicity scale for the interesting test set of the quaternary ammonium cations can be roughly determined. © 2010 American Chemical Society.

  5. Immunoparesis in newly diagnosed Multiple Myeloma patients

    DEFF Research Database (Denmark)

    Sorrig, Rasmus; Klausen, Tobias W.; Salomo, Morten

    2017-01-01

    Immunoparesis (hypogammaglobulinemia) is associated to an unfavorable prognosis in newly diagnosed Multiple myeloma (MM) patients. However, this finding has not been validated in an unselected population-based cohort. We analyzed 2558 newly diagnosed MM patients in the Danish Multiple Myeloma...

  6. Quaternary nanofossils on the Brazilian continental shelf; Nanofosseis calcarios do quaternario da margem continental brasileira

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, Rogerio Loureiro [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Gerencia de Bioestratigrafia e Paleoecologia], E-mail: rlantunes@petrobras.com.br

    2007-07-01

    The study of calcareous nanofossils occurring in the deposits on the Brazilian continental margin began in the late 1960s, undertaken solely by PETROBRAS. Instead of presenting an academic outlook, the purpose of these investigations is first to formulate a biostratigraphic framework to apply to oil well samples. The initial result was the first zoning for the Brazilian continental margin, which considered the deposits formed between the Aptian and Miocene series. Since the 1960s to date, many papers have been written either with details of that original zoning or applying nanofossil biostratigraphy to solve stratigraphic problems. Regardless of all the papers and studies undertaken, little attention has been paid to the Quaternary, since these deposits are normally of no interest to petroleum geology stricto sensu, especially in a large part of the Brazilian margin. On the other hand, there are a few articles and some Master's dissertations and PhD theses that were written and/or are in progress in Brazilian universities. On the other hand, elsewhere in the world, Quaternary nanofossils have been thoroughly investigated in terms of biostratigraphy and paleoceanography. It is, therefore, very clear that there is a gap between what is being done elsewhere in the world and what has been done in Brazil. In fact, this gap is not larger simply because of a few researchers in Brazilian universities who are studying this topic. The intention of this paper is to contribute toward a richer study of Quaternary nanofossils. It, therefore, contains illustrations and taxonomic descriptions of many species observed in the younger strata of the Brazilian margin basins. This article not only aspires to portray and disseminate the potential of nanofossils for the marine Quaternary study but is also an invitation to students (under and post-graduates) and university researchers - an invitation to learn a little more about the subject and spend some time studying these real gems

  7. Quaternary nanofossils on the Brazilian continental shelf; Nanofosseis calcarios do quaternario da margem continental brasileira

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, Rogerio Loureiro [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Gerencia de Bioestratigrafia e Paleoecologia], E-mail: rlantunes@petrobras.com.br

    2007-07-01

    The study of calcareous nanofossils occurring in the deposits on the Brazilian continental margin began in the late 1960s, undertaken solely by PETROBRAS. Instead of presenting an academic outlook, the purpose of these investigations is first to formulate a biostratigraphic framework to apply to oil well samples. The initial result was the first zoning for the Brazilian continental margin, which considered the deposits formed between the Aptian and Miocene series. Since the 1960s to date, many papers have been written either with details of that original zoning or applying nanofossil biostratigraphy to solve stratigraphic problems. Regardless of all the papers and studies undertaken, little attention has been paid to the Quaternary, since these deposits are normally of no interest to petroleum geology stricto sensu, especially in a large part of the Brazilian margin. On the other hand, there are a few articles and some Master's dissertations and PhD theses that were written and/or are in progress in Brazilian universities. On the other hand, elsewhere in the world, Quaternary nanofossils have been thoroughly investigated in terms of biostratigraphy and paleoceanography. It is, therefore, very clear that there is a gap between what is being done elsewhere in the world and what has been done in Brazil. In fact, this gap is not larger simply because of a few researchers in Brazilian universities who are studying this topic. The intention of this paper is to contribute toward a richer study of Quaternary nanofossils. It, therefore, contains illustrations and taxonomic descriptions of many species observed in the younger strata of the Brazilian margin basins. This article not only aspires to portray and disseminate the potential of nanofossils for the marine Quaternary study but is also an invitation to students (under and post-graduates) and university researchers - an invitation to learn a little more about the subject and spend some time studying these real gems of

  8. Pliocene-Quaternary history of Futuna island, south Vanuatu, southwest Pacific

    International Nuclear Information System (INIS)

    Neef, G.; McCulloch, M.T.

    2001-01-01

    Uranium-series ages from thermal ionisation mass spectrometry are reported here for the raised coral reefs of Futuna Island, which lies adjacent to the eastern margin of the backarc Futuna Trough in south Vanuatu, southwest Pacific. U-series ages from coral from the lowest raised reef indicate that its upper part is most likely to be ca 210 ka, whereas the most elevated raised reef has a likely age of ca 520 ka (range 600-440 ka). The inferred Pliocene-Quaternary history for Futuna Island and the adjacent Futuna Trough is: (i) formation of the Pliocene - Early Quaternary basaltic-andesite cone in a southeast part of the Vanuatu Island Arc; (ii) inception of the Futuna Trough (adjacent to the west margin of Futuna Island) since 1.8Ma; (iii) subsequent uplift of the volcanic cone above sea-level caused ∼ 500 m of its upper part to be removed by marine erosion; (iv) the island then subsided and at least 160 m of limestone was deposited on the truncated cone; and (v) during the period 520 ka to ca 210 ka seven fringing reefs formed at the margin of the cone as the island was uplifted. Since ca 210 ka Futuna further subsided and, as a result, the post ca 210 ka history of the island is obscure. Copyright (2001) Geological Society of Australia

  9. [Quaternary prevention: An attempt to avoid the excesses of Medicine].

    Science.gov (United States)

    Noble, María

    2015-09-01

    Seduced by technology, biometrics, practical guidelines and the use of medication, medicine has been driven away from the subject of its care. Quaternary prevention is, among other voices around the world, trying to denounce the consequent excesses of medical practice given by this situation. There are visible excesses, such as the long list of studies being performed on patients without indication, and others, much more subtle, as excessive prevention and the continuous and progressive medicalization of life itself that are rooted in our culture and demanded by a society that requests certainty at almost any cost. Quaternary prevention proposes a series of actions leaning towards avoiding and diminishing the damage produced by health care activities, in order to protect the subject of overdiagnosis and overtreatment; offering also ethical and viable alternatives in which the balance of risks and benefits (based on the best evidences) respects the autonomy of the subject by properly informing and allowing him to decide among the best options he has; altogether in a process that contemplates a rational and equitable use of resources. In order to achieve this, reliable sources of information and a medical education not dependent on industries related to technology or pharmaceuticals, are vital; in conjuction with a medicine that restablishes the subject as its main and central interest.

  10. Enantioselective construction of quaternary N-heterocycles by palladium-catalysed decarboxylative allylic alkylation of lactams

    KAUST Repository

    Behenna, Douglas C.

    2011-12-18

    The enantioselective synthesis of nitrogen-containing heterocycles (N-heterocycles) represents a substantial chemical research effort and resonates across numerous disciplines, including the total synthesis of natural products and medicinal chemistry. In this Article, we describe the highly enantioselective palladium-catalysed decarboxylative allylic alkylation of readily available lactams to form 3,3-disubstituted pyrrolidinones, piperidinones, caprolactams and structurally related lactams. Given the prevalence of quaternary N-heterocycles in biologically active alkaloids and pharmaceutical agents, we envisage that our method will provide a synthetic entry into the de novo asymmetric synthesis of such structures. As an entry for these investigations we demonstrate how the described catalysis affords enantiopure quaternary lactams that intercept synthetic intermediates previously used in the synthesis of the Aspidosperma alkaloids quebrachamine and rhazinilam, but that were previously only available by chiral auxiliary approaches or as racemic mixtures. © 2012 Macmillan Publishers Limited. All rights reserved.

  11. Quaternary system LiF-LiCl-LiVO3-Li2MoO4

    International Nuclear Information System (INIS)

    Anipchenko, B.V.; Garkushin, I.K.

    2000-01-01

    Interactions in the LiF-LiCl-LiVO 3 -Li 2 MoO 4 system are studied by differential thermal analysis. Rate of heating/cooling of the samples comprised 15 Grad/min, mass of sample composed 0.2 g. The system was investigated in the 300-650 Deg C range. X-ray diffraction method was used for determination of purity of the reagents. Composition and temperature of quaternary component eutectics are determined: 16.5 mol. % of LiF, 47.0 mol. % of LiCl, 28.8 mol. % of LiVO 3 , 7.6 mol. % of Li 2 MoO 4 ; 387 Deg C. Mean value of melting enthalpy of quaternary eutectics mixture in the LiF-LiCl-LiVO 3 -Li 2 MoO 4 system on the results of the tests was in the range of 222 kJ/kg [ru

  12. Small Quaternary Inhibitors K298 and K524: Cholinesterases Inhibition, Absorption, Brain Distribution, and Toxicity.

    Science.gov (United States)

    Karasova, Jana Zdarova; Hroch, Milos; Musilek, Kamil; Kuca, Kamil

    2016-02-01

    Inhibitors of acetylcholinesterase (AChE) may be used in the treatment of various cholinergic deficits, among them being myasthenia gravis (MG). This paper describes the first in vivo data for promising small quaternary inhibitors (K298 and K524): acute toxicity study, cholinesterase inhibition, absorption, and blood-brain barrier penetration. The newly prepared AChE inhibitors (bis-quinolinium and quinolinium compounds) possess a positive charge in the molecule which ensures that anti-AChE action is restricted to peripheral effect. HPLC-MS was used for determination of real plasma and brain concentration in the pharmacokinetic part of the study, and standard non-compartmental analysis was performed. The maximum plasma concentrations were attained at 30 min (K298; 928.76 ± 115.20 ng/ml) and 39 min (K524; 812.40 ± 54.96 ng/ml) after i.m. Both compounds are in fact able to target the central nervous system. It seems that the difference in the CNS distribution profile depends on an active efflux system. The K524 brain concentration was actively decreased to below an effective level; in contrast, K298 progressively accumulated in brain tissue. Peripheral AChE inhibitors are still first-line treatment in the mild forms of MG. Commonly prescribed carbamates have many severe side effects related to AChE carbamylation. The search for new treatment strategies is still important. Unlike carbamates, these new compounds target AChE via apparent π-π or π-cationic interaction aside at the AChE catalytic site.

  13. A revision of the Pliocene and Quaternary Lutrinae from Europe

    OpenAIRE

    Willemsen, G.F.

    1992-01-01

    In this paper, a revision of the Pliocene and Quaternary Lutrinae from Europe is presented. Such a revision, including fossil material, has not been published since the work of Pohle (1919). Three tribes within the Lutrinae are recognized: the Lutrini, the Aonyxini and the Enhydrini. The latter comprises both Enhydra and the Enhydriodon group. The genus Nesolutra, consisting of three insular species, is not retained. Two are included in Lutra and for N. ichnusae a new genus, Sardolutra, is pr...

  14. Biotic response to late Quaternary rapid climate switches in Santa Barbara Basin: Ecological and evolutionary implications

    International Nuclear Information System (INIS)

    Cannariato, K.G.; Kennett, J.P.; Behl, R.J.

    1999-01-01

    Benthic foraminiferal assemblages from Santa Barbara Basin exhibit major faunal and ecological switches associated with late Quaternary millennial- to decadal-scale global climate oscillations. Repeated turnovers of entire faunas occurred rapidly (<40--400 yr) without extinction or speciation in conjunction with Dansgaard-Oeschger shifts in thermohaline circulation, ventilation, and climate, confirming evolutionary model predictions of Roy et al. Consistent faunal successions of dysoxic taxa during successive interstadials reflect the extreme sensitivity and adaptation of the benthic ecosystem to the rapid environmental changes that marked the late Quaternary and possibly other transitional intervals in the history of the Earth's ocean-atmosphere-cryosphere system. These data support the hypothesis that broad segments of the biosphere are well adapted to rapid climate change

  15. Assessment by X-ray diffraction the process of bentonite organophilization using a different quaternary ammonium salts

    International Nuclear Information System (INIS)

    Silva, L.A. da; Rosario, J.A. do; Lima, R.B.; Milioli, C.C.; Gusatti, M.; Linhares, R.H.; Kuhnen, N.C.; Riella, H.G.

    2010-01-01

    The process was conducted in an organophilization Bentonite originated from the Company of Industrial Minerals of Mozambique Ltd. (Mimoc). The transformation of bentonite organophilic clay were performed in laboratory procedures that aim to mechanochemical exchange of Na + and Ca 2+ from the interlayer space of clay minerals by cations of quaternary ammonium salts. In this study we used two types of salts, which are: the cetyl trimethyl ammonium chloride and alkyl dimethyl benzyl ammonium chloride at different concentrations (30, 50, 80, 100 meq/100 g clay). The natural bentonite and organophilic clay samples were characterized by X-ray diffraction (XRD) to obtain the mineralogical constituents and analysis phases of the increase in interlayer distance confirming the incorporation of quaternary ammonium salts in the structure of clays. (author)

  16. Quaternary structure of methemoglobin

    International Nuclear Information System (INIS)

    Chevion, M.; Ilan, Y.A.; Samuni, A.; Navok, T.; Czapski, G.

    1979-01-01

    The pulse radiolysis of solutions of adult human methemoglobin was used to reduce a single heme iron within the protein tetramers. The valence hybrids thus formed were reacted with oxygen. Kinetics of the reactions were studied. The effects of pH and inositol hexaphosphate were examined. The kinetics of the ligation of oxygen to stripped valence hybrids showed a single phase behavior at the pH range 6.5 to 9. As the pH was lowered below 6.5, a second, slower phase became apparent. In the presence of inositol hexaphosphate, above pH 8, the kinetics of oxygen binding was of a single phase. As the pH was lowered, a transition to a second, slower phase was noticed. Below pH 7, the slower phase was the only detectable one. On this basis, it is concluded that human adult stripped methemoglobin resides in an R quarternary structure, while the presence of IHP stabilizes the T structure at pH below 7.5. This transition between the quaternary structures of methemoglobin cannot be accounted for by the switch between the high spin and the low spin states of the ferric iron. This switch of spin state takes place at pH>8.2

  17. Generational differences among newly licensed registered nurses.

    Science.gov (United States)

    Keepnews, David M; Brewer, Carol S; Kovner, Christine T; Shin, Juh Hyun

    2010-01-01

    Responses of 2369 newly licensed registered nurses from 3 generational cohorts-Baby Boomers, Generation X, and Generation Y-were studied to identify differences in their characteristics, work-related experiences, and attitudes. These responses revealed significant differences among generations in: job satisfaction, organizational commitment, work motivation, work-to-family conflict, family-to-work conflict, distributive justice, promotional opportunities, supervisory support, mentor support, procedural justice, and perceptions of local job opportunities. Health organizations and their leaders need to anticipate intergenerational differences among newly licensed nurses and should provide for supportive working environments that recognize those differences. Orientation and residency programs for newly licensed nurses should be tailored to the varying needs of different generations. Future research should focus on evaluating the effectiveness of orientation and residency programs with regard to different generations so that these programs can be tailored to meet the varying needs of newly licensed nurses at the start of their careers. Copyright 2010 Mosby, Inc. All rights reserved.

  18. Water-quality characteristics of quaternary unconsolidated-deposit aquifers and lower tertiary aquifers of the Bighorn Basin, Wyoming and Montana, 1999-2001

    Science.gov (United States)

    Bartos, Timothy T.; Eddy-Miller, Cheryl A.; Norris, Jody R.; Gamper, Merry E.; Hallberg, Laura L.

    2004-01-01

    As part of the Yellowstone River Basin National Water Quality Assessment study, ground-water samples were collected from Quaternary unconsolidated-deposit and lower Tertiary aquifers in the Bighorn Basin of Wyoming and Montana from 1999 to 2001. Samples from 54 wells were analyzed for physical characteristics, major ions, trace elements, nutrients, dissolved organic carbon, radionuclides, pesticide compounds, and volatile organic compounds (VOCs) to evaluate current water-quality conditions in both aquifers. Water-quality samples indicated that waters generally were suitable for most uses, and that natural conditions, rather than the effects of human activities, were more likely to limit uses of the waters. Waters in both types of aquifers generally were highly mineralized, and total dissolved-solids concentrations frequently exceeded the U.S. Environmental Protection Agency (USEPA) Secondary Maximum Contaminant Level (SMCL) of 500 milligrams per liter (mg/L). Because of generally high mineralization, waters from nearly one-half of the samples from Quaternary aquifers and more than one-half of the samples from lower Tertiary aquifers were not classified as fresh (dissolved-solids concentration were not less than 1,000 mg/L). The anions sulfate, fluoride, and chloride were measured in some ground-water samples at concentrations greater than SMCLs. Most waters from the Quaternary aquifers were classified as very hard (hardness greater than 180 mg/L), but hardness varied much more in waters from the lower Tertiary aquifers and ranged from soft (less than 60 mg/L) to very hard (greater than 180 mg/L). Major-ion chemistry varied with dissolved-solids concentrations. In both types of aquifers, the predominant anion changes from bicarbonate to sulfate with increasing dissolved-solids concentrations. Samples from Quaternary aquifers with fresh waters generally were calcium-bicarbonate, calcium-sodium-bicarbonate, and calcium-sodium-sulfate-bicarbonate type waters, whereas

  19. OPTIMIZATION OF TRANSESTERIFICATION PARAMETERS FOR OPTIMAL BIODIESEL YIELD FROM CRUDE JATROPHA OIL USING A NEWLY SYNTHESIZED SEASHELL CATALYST

    Directory of Open Access Journals (Sweden)

    A. N. R. REDDY

    2017-10-01

    Full Text Available Heterogeneous catalysts are promising catalysts for optimal biodiesel yield from transesterification of vegetable oils. In this work calcium oxide (CaO heterogeneous catalyst was synthesized from Polymedosa erosa seashell. Calcination was carried out at 900ºC for 2h and characterized using Fourier transform infrared spectroscopy. Catalytic efficiency of CaO was testified in transesterification of crude Jatropha oil (CJO. A response surface methodology (RSM based on five-level-two-factor central composite design (CCD was employed to optimize two critical transesterification parameters catalyst concentration to pretreated CJO (0.01-0.03 w/w % and the reaction time (90 min - 150 min. A JB yield of 96.48% was estimated at 0.023 w/w% catalyst and 125.76 min reaction using response optimizer. The legitimacy of the predicted model was verified through the experiments. The validation experiments conformed a yield of JB 96.4%±0.01% as optimal at 0.023 w/w% catalyst to pretreated oil ratio and 126 min reaction time.

  20. Electrical imaging and self-potential survayes to study the geological setting of the Quaternary, slope depositsin the Agri high valley (Southern Italy)

    OpenAIRE

    M. Schiattarella; S. Piscitelli; V. Lapenna; S. I. Giano

    2000-01-01

    We present the results of a geophysical survey carried out to outline the structural modelling of Quaternary slopedeposits in the northern part of the Agri high valley (Basilicata, Southern Italy). Quaternary folding and brittle deformations of the subaerial slope deposits have been studied combining electrical imaging and self-potential surveys with geological structural analysis. This integrated approach indicates that the area underwent both transpressional and transtensional tectonics dur...

  1. Surface Functionalization of Polyethersulfone Membrane with Quaternary Ammonium Salts for Contact-Active Antibacterial and Anti-Biofouling Properties

    Directory of Open Access Journals (Sweden)

    Xiao Hu

    2016-05-01

    Full Text Available Biofilm is a significant cause for membrane fouling. Antibacterial-coated surfaces can inhibit biofilm formation by killing bacteria. In this study, polyethersulfone (PES microfiltration membrane was photografted by four antibiotic quaternary ammonium compounds (QACs separately, which were synthesized from dimethylaminoethyl methacrylate (DMAEMA by quaternization with butyl bromide (BB, octyl bromide (OB, dodecyl bromide (DB, or hexadecyl bromide (HB. XPS, ATR-FTIR, and SEM were used to confirm the surfaces’ composition and morphology. After modification, the pores on PES-g-DMAEMA-BB and PES-g-DMAEMA-OB were blocked, while PES-g-DMAEMA-DB and PES-g-DMAEMA-HB were retained. We supposed that DMAEMA-BB and DMAEMA-OB aggregated on the membrane surface due to the activities of intermolecular or intramolecular hydrogen bonds. Bacteria testing found the antibacterial activities of the membranes increased with the length of the substituted alkyl chain. Correspondingly, little bacteria were observed on PES-g-DMAEMA-DB and PES-g-DMAEMA-HB by SEM. The antifouling properties were investigated by filtration of a solution of Escherichia coli. Compared with the initial membrane, PES-g-DMAEMA-DB and PES-g-DMAEMA-HB showed excellent anti-biofouling performance with higher relative flux recovery (RFR of 88.3% and 92.7%, respectively. Thus, surface functionalization of the PES membrane with QACs can prevent bacteria adhesion and improve the anti-biofouling activity by the contact-active antibacterial property.

  2. Paleomagnetic dating of tectonically influenced Plio-Quaternary fan-system deposits from the Apennines (Italy

    Directory of Open Access Journals (Sweden)

    Michele Saroli

    2015-03-01

    Full Text Available The Roveto Valley is a narrow, elongated, NW-trending depression filled with continental Plio-Quaternary deposits that outcrop at different topographic elevations. A morpho-lithostratigraphic succession of the continental deposits has been defined in order to reconstruct the geological Quaternary evolution of the area. These deposits do not contain materials suitable for biostratigraphic dating; therefore, in order to determine their chronology, three different units were sampled for magnetostratigraphic investigations. Paleomagnetic results demonstrated that standard demagnetization techniques are effective in removing secondary remanence components and in isolating the characteristic remanent magnetization, allowing us to determine, for each cycle, whether it was deposited before or after the Brunhes-Matuyama geomagnetic reversal at 781 ka. Preliminary rock magnetic analyses indicated that magnetite is the main magnetic carrier and that hematite, which gives the pink colour to the matrix, is in the superparamagnetic grain-size range and thus does not retain any paleomagnetic remanence.

  3. Growth of quaternary InAlGaN barrier with ultrathin thickness for HEMT application

    Science.gov (United States)

    Li, Zhonghui; Li, Chuanhao; Peng, Daqing; Zhang, Dongguo; Dong, Xun; Pan, Lei; Luo, Weike; Li, Liang; Yang, Qiankun

    2018-06-01

    Quaternary InAlGaN barriers with thickness of 7 nm for HEMT application were grown on 3-inch semi-insulating 4H-SiC substrates by metal organic chemical vapor deposition (MOCVD). Focused on growth mechanism of the InAlGaN barrier, the surface morphology and characteristics of InAlGaN/AlN/GaN heterostructures were studied with different growth parameters, including the temperature, Al/Ga ratio and chamber pressure. Among the as-grown samples, high electron mobility is consistent with smooth surface morphology, while high crystalline quality of the quaternary barrier is confirmed by measurements of Photoluminescence (PL) and Mercury-probe Capacity-Voltage (C-V). The recommended heterostructures without SiN passivation is characterized by mobility of 1720 cm2/(V·s), 2DEG density of 1.71*1013 cm-2, sheet resistance of about 210 Ω/□ with a smooth surface morphology and moderate tensile state, specially applied for microwave devices.

  4. PULSE SYNTHESIZING GENERATOR

    Science.gov (United States)

    Kerns, Q.A.

    1963-08-01

    >An electronlc circuit for synthesizing electrical current pulses having very fast rise times includes several sinewave generators tuned to progressively higher harmonic frequencies with signal amplitudes and phases selectable according to the Fourier series of the waveform that is to be synthesized. Phase control is provided by periodically triggering the generators at precisely controlled times. The outputs of the generators are combined in a coaxial transmission line. Any frequency-dependent delays that occur in the transmission line can be readily compensated for so that the desired signal wave shape is obtained at the output of the line. (AEC)

  5. Anti-inflammatory and antinociceptive evaluation of newly synthesized 4-(substituted ethanoyl amino-3-mercapto-5-(4-methoxy phenyl-1,2,4-triazoles

    Directory of Open Access Journals (Sweden)

    Neeraj Upmanyu

    2011-01-01

    Full Text Available Introduction: 1,2,4-triazoles and its derivatives have been reported to possess anti-inflammatory, analgesic, antimicrobial, anticancer, antitumor, antitubercular, anticonvulsant, openers of Ca-activated potassium (Maxi-K channels, antiviral properties, hypoglycemic, anxiolytic and antidepressant activity. Therefore, 1,2,4-triazole seems to be an important pharmacophore. Materials and Methods: The synthesis of 4-(substituted ethanoyl amino-3-mercapto-5-(4-methoxy phenyl-1,2,4-triazoles (6a-o were prepared following six step starting 4-methoxy benzoic acid and using different secondary amines and were characterized with the help of FT-IR, 1 H, 13 C NMR, FAB Mass and nitrogen analysis. These synthesized compounds (6a-o were then evaluated for anti-inflammatory activity by carrageenan induced paw edema method.Out of these synthesized compounds, some (6f, i and k were evaluated for antinociceptive activity by Hot plate method and Tail immersion method. Results and Discussion: The synthesis of 4-(substituted amino-3-mercapto-5-(4-methoxy phenyl-1,2,4-triazoles (6a-o was accomplished. The IR spectra exhibited characteristic bands for C-N, C=N, SH and C=O at 1350-1360, 1511-1548, 2520-2594.3 and 1650-1719 cm -1 . The C-O-C asymmetric and symmetric str. was at 1250-1254 and 1027-1079.3 cm -1 respectively. In 1 H-NMR spectra, a singlet of CONH was found in the range of δ 9.92-10.18 ppm and another singlet of thiol group was observed in the range of δ 8.63-9.92 ppm. A singlet of Ar-OCH 3 was also found between δ 3.57-3.91 ppm. In 13 C- NMR spectra, C-3 and C-5 of the 1,2,4 - triazole nucleus were observed in the range of δ 147-166.9 ppm. Carbonyl carbon and methylene carbon of -NHCOCH 2 N< were found between δ 166.5-177.5 and δ 47.1-62 ppm respectively. Acute toxicity study was donr following OECD-423 and cut-off dose was found to be between 1000-1500 mg/kg body weight. At the dose level of 100 mg/kg, 6f, 6i and 6k exhibited appreciable inhibition

  6. Quaternary phosphorites from the continental margin off Chennai, southeast India: Analogs of ancient phosphate stromatolites

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Rao, K.M.; Raju, D.S.N.

    . The microbial mats were formed on the outer shelf, most probably during conditions of low sea level in the Quaternary, and microbial processes played a major role in direct phosphatization of these mats. The primary phosphorus source seems to have been...

  7. Study of proton and carbon 13 nuclear magnetic resonance spectra of an allyl phenol derivatives series; Estudo de espectros de ressonancia magnetica nuclear protonica e de carbono 13 de uma serie de derivados de alilfenois

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Thais Horta Alvares da [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Farmacia. Dept. de Produtos Farmaceuticos; Oliveira, Alaide Braga de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica

    1991-12-31

    Quaternary ammonium salt derivates of natural ally phenols were synthesized with the purpose of obtaining peripheral analgesics. Eugenol, O-methyleugenol and safrole were submitted to nitration, reduction, per methylation. The amines were also transformed into their hydro chlorides. The {sup 1} HNMR spectra of the nitro compounds, amines, amine hydro chlorides, quaternary ammonium salts and dymethylamines were analysed, as well as the {sup 13} C NMR spectra of the nitro compounds and of the quaternary ammonium salts. (author). 8 refs., 4 tabs.

  8. Absolute age determination of quaternary faults

    International Nuclear Information System (INIS)

    Cheong, Chang Sik; Lee, Seok Hoon; Choi, Man Sik

    2000-03-01

    To constrain the age of neotectonic fault movement, Rb-Sr, K-Ar, U-series disequilibrium, C-14 and Be-10 methods were applied to the fault gouges, fracture infillings and sediments from the Malbang, Ipsil, Wonwonsa faults faults in the Ulsan fault zone, Yangsan fault in the Yeongdeog area and southeastern coastal area. Rb-Sr and K-Ar data imply that the fault movement of the Ulan fault zone initiated at around 30 Ma and preliminary dating result for the Yang san fault is around 70 Ma in the Yeongdeog area. K-Ar and U-series disequilibrium dating results for fracture infillings in the Ipsil fault are consistent with reported ESR ages. Radiocarbon ages of quaternary sediments from the Jeongjari area are discordant with stratigraphic sequence. Carbon isotope data indicate a difference of sedimentry environment for those samples. Be-10 dating results for the Suryum fault area are consistent with reported OSL results

  9. Absolute age determination of quaternary faults

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Chang Sik; Lee, Seok Hoon; Choi, Man Sik [Korea Basic Science Institute, Seoul (Korea, Republic of)] (and others)

    2000-03-15

    To constrain the age of neotectonic fault movement, Rb-Sr, K-Ar, U-series disequilibrium, C-14 and Be-10 methods were applied to the fault gouges, fracture infillings and sediments from the Malbang, Ipsil, Wonwonsa faults faults in the Ulsan fault zone, Yangsan fault in the Yeongdeog area and southeastern coastal area. Rb-Sr and K-Ar data imply that the fault movement of the Ulan fault zone initiated at around 30 Ma and preliminary dating result for the Yang san fault is around 70 Ma in the Yeongdeog area. K-Ar and U-series disequilibrium dating results for fracture infillings in the Ipsil fault are consistent with reported ESR ages. Radiocarbon ages of quaternary sediments from the Jeongjari area are discordant with stratigraphic sequence. Carbon isotope data indicate a difference of sedimentry environment for those samples. Be-10 dating results for the Suryum fault area are consistent with reported OSL results.

  10. New quaternary ammonium salts based decontaminants

    Directory of Open Access Journals (Sweden)

    Diana M. Popescu

    2014-06-01

    Full Text Available Decontamination after terrorist attacks or industrial accidents with biological and/or chemical agents („bio-chem“ must be fast and efficient, in order to reduce the number of victims and to eliminate the consequent damages. The decontamination of living biological agents (bacteria, viruses or nonliving ones (toxins, regulators and toxic chemicals could be accomplished by reactions of hydrolysis in various experimental conditions, in particular in alkaline medium, reactions with amines or ammonia, alcohols, phenols etc. and by their transformation into less toxic degradation products. “Bio-chem” intentional or unintentional contamination is a real risk, towards which an effective management must be available to prevent and control it. Decontamination is an essential measure to protect the personnel and the environment. Synthesis and testing of new „bio-chem“ decontaminants, based on quaternary ammonium salts, complete the arsenal of protection against chemical and biological agents. The most effective selected substances could be produced and used for decontamination in accordance with legal procedures

  11. Establishment probability in newly founded populations

    Directory of Open Access Journals (Sweden)

    Gusset Markus

    2012-06-01

    Full Text Available Abstract Background Establishment success in newly founded populations relies on reaching the established phase, which is defined by characteristic fluctuations of the population’s state variables. Stochastic population models can be used to quantify the establishment probability of newly founded populations; however, so far no simple but robust method for doing so existed. To determine a critical initial number of individuals that need to be released to reach the established phase, we used a novel application of the “Wissel plot”, where –ln(1 – P0(t is plotted against time t. This plot is based on the equation P0t=1–c1e–ω1t, which relates the probability of extinction by time t, P0(t, to two constants: c1 describes the probability of a newly founded population to reach the established phase, whereas ω1 describes the population’s probability of extinction per short time interval once established. Results For illustration, we applied the method to a previously developed stochastic population model of the endangered African wild dog (Lycaon pictus. A newly founded population reaches the established phase if the intercept of the (extrapolated linear parts of the “Wissel plot” with the y-axis, which is –ln(c1, is negative. For wild dogs in our model, this is the case if a critical initial number of four packs, consisting of eight individuals each, are released. Conclusions The method we present to quantify the establishment probability of newly founded populations is generic and inferences thus are transferable to other systems across the field of conservation biology. In contrast to other methods, our approach disaggregates the components of a population’s viability by distinguishing establishment from persistence.

  12. Characterization of quaternary metal oxide films by synchrotron x-ray fluorescence microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Perry, D.L.; Thompson, A.C.; Russo, R.E. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    A high demand for thin films in industrial technology has been responsible for the creation of new techniques for the fabrication of such films. One highly effective method for the syntheses of variable composition thin films is pulsed-laser deposition (PLD). The technique has a large number of characteristics which make it an attractive approach for making films. It offers rapid deposition rates, congruent material transfer, simple target requirements from which to make the films, in situ multilayer deposition, and no gas composition or pressure requirements. Additionally, the technique can also afford crystalline films and films with novel structures. Pulsed-laser deposition can be used to make films of semiconductors, insulators, high-temperature superconductors, diamond-like films, and piezoelectric materials. Quaternary metal oxides involving calcium, nickel, and potassium have been shown to be quite effective in the catalysis of coal gasification and methane coupling. One approach to incorporating all three of the metal oxides into one phase is the use of laser ablation to prepare films of the catalysts so that they may be used for coatings, smooth surfaces on which to conduct detailed studies of gas-solid interface reactions that are involved in catalytic processes, and other applications. The problem of dissimilar boiling points of the three metal oxides system is overcome, since the laser ablation process effects the volatilization of all three components from the laser target essentially simultaneously. There is strong interest in gaining an understanding of the chemical and morphological aspects of the films that are deposited. Phenomena such as lattice defects and chemical heterogeneity are of interest. The experimental data discussed here are restricted to the matrix homogeneity of the films themselves for films which were void of microparticles.

  13. Micropaleontologic record of Quaternary paleoenvironments in the Central Albemarle Embayment, North Carolina, U.S.A.

    Science.gov (United States)

    Culver, Stephen J.; Farrell, Kathleen M.; Mallinson, David J.; Willard, Debra A.; Horton, Benjamin P.; Riggs, Stanley R.; Thieler, E. Robert; Wehmiller, John F.; Parham, Peter; Snyder, Scott W.; Hillier, Caroline

    2011-01-01

    To understand the temporal and spatial variation of eustatic sea-level fluctuations, glacio-hydro-isostacy, tectonics, subsidence, geologic environments and sedimentation patterns for the Quaternary of a passive continental margin, a nearly complete stratigraphic record that is fully integrated with a three dimensional chronostratigraphic framework, and paleoenvironmental information are necessary. The Albemarle Embayment, a Cenozoic regional depositional basin in eastern North Carolina located on the southeast Atlantic coast of the USA, is an ideal setting to unravel these dynamic, interrelated processes.Micropaleontological data, coupled with sedimentologic, chronostratigraphic and seismic data provide the bases for detailed interpretations of paleoenvironmental evolution and paleoclimates in the 90. m thick Quaternary record of the Albemarle Embayment. The data presented here come from a transect of cores drilled through a barrier island complex in the central Albemarle Embayment. This area sits in a ramp-like setting between late Pleistocene incised valleys.The data document the episodic infilling of the Albemarle Embayment throughout the Quaternary as a series of transgressive-regressive (T-R) cycles, characterized by inner shelf, midshelf, and shoreface assemblages, that overlie remnants of fluvial to estuarine valley-fill. Barrier island and marginal marine deposits have a low preservation potential. Inner to mid-shelf deposits of the early Pleistocene are overlain by similar middle Pleistocene shelf sediments in the south of the study area but entirely by inner shelf deposits in the north. Late Pleistocene marine sediments are of inner shelf origin and Holocene deposits are marginal marine in nature. Pleistocene marine sediments are incised, particularly in the northern half of the embayment by lowstand paleovalleys, partly filled by fluvial/floodplain deposits and in some cases, overlain by remnants of transgressive estuarine sediments. The shallowing

  14. Specialization in plant-hummingbird networks is associated with species richness, contemporary precipitation and quaternary climate-change velocity

    DEFF Research Database (Denmark)

    Dalsgaard, Bo; Magård, Else; Fjeldså, Jon

    2011-01-01

    patterns of contemporary biotic specialization and its drivers, we use network analysis to determine the degree of specialization in plant-hummingbird mutualistic networks sampled at 31 localities, spanning a wide range of climate regimes across the Americas. We found greater biotic specialization at lower...... latitudes, with latitude explaining 20-22% of the spatial variation in plant-hummingbird specialization. Potential drivers of specialization--contemporary climate, Quaternary climate-change velocity, and species richness--had superior explanatory power, together explaining 53-64% of the variation...... specialization. These results suggest that both ecological and evolutionary processes at Quaternary time scales can be important in driving large-scale geographical patterns of contemporary biotic specialization, at least for co-evolved systems such as plant-hummingbird networks....

  15. Late Quaternary paleoseismicity and seismic potential of the Yilan-Yitong Fault Zone in NE China

    Science.gov (United States)

    Yu, Zhongyuan; Yin, Na; Shu, Peng; Li, Jincheng; Wei, Qinghai; Min, Wei; Zhang, Peizhen

    2018-01-01

    The Yilan-Yitong Fault Zone (YYFZ), which is composed of two nearly parallel branches with a spacing of 5-30 km and a length of ∼1100 km, is considered to be the key branch of the Tancheng-Lujiang Fault Zone (TLFZ) in NE China. It was traditionally believed that the YYFZ experienced weak activity or was inactive during the Late Quaternary, without the capability to generate strong earthquakes (M ≥ 7), based on the absence of typical outcrops and large historical or instrumental earthquakes (M > 6). However, our paleoseismic study shows that the YYFZ is the primary seismotectonic structure (M ≥ 7) that poses significant earthquake threats to NE China. The synthesis of data collected from geologic investigations, geomorphic mapping, trench logging and the dating of samples indicates that the YYFZ is an active structure that has undergone segmented strong tectonic deformation since the Late Quaternary with a characteristic assemblage of landforms, including linear scarps and troughs, offset or deflected streams, linear sag ponds, small horsts and grabens. The latest ruptures of the YYFZ migrated from previous boundary faults into the basin interior, forming a left-stepping en echelon pattern in plain view, and the kinematics of these events in the Late Quaternary were dominated by reverse dextral slipping. Multi-segment cluster faulting might have occurred during three cluster periods, i.e., ∼34750-35812 a BP, ∼21700-22640 a BP, and ∼4000 a BP-present, which implies that the recurrence interval of large earthquakes along the YYFZ may be as long as tens of thousands of years.

  16. External controls on Quaternary fluvial incision and terrace formation at the Segre River, Southern Pyrenees

    NARCIS (Netherlands)

    Stange, K.M.; van Balen, R.T.; Vandenberghe, J.; Peña, J.L.; Sancho, C.

    2013-01-01

    Focusing on climatic- and structural (tectonic) controls, we aim to determine their relative importance for the (Pliocene to Quaternary) fluvial landscape evolution in the Southern Pyrenees foreland. We investigate the Segre River, which is one of the major streams of the Southern Pyrenees that

  17. Total Syntheses of Polycyclic Polyprenylated Acylphloroglucinol Natural Products and Analogs Utilizing Alkylative Dearomatizations and Cationic Cyclizations

    Science.gov (United States)

    Boyce, Jonathan H.

    Polycyclic polyprenylated acylphloroglucinols (PPAPs) are structurally complex natural products with promising biological activities. These compounds have interesting anticancer and anti-HIV properties as well as other biological activities making them highly attractive synthetic targets. We report a stereodivergent, asymmetric total synthesis of (-)-clusianone in six steps from commercial materials. We have implemented a challenging cationic cyclization forging a bond between two sterically encumbered quaternary carbon atoms. Mechanistic studies point to the unique ability of formic acid to mediate the cyclization forming the clusianone framework. We also present a biosynthesis-inspired, diversity-oriented synthesis approach for rapid construction of PPAP analogs via palladium-catalyzed dearomative conjunctive allylic alkylation (DCAA). These efficient palladium-catalyzed protocols construct the [3.3.1]-bicyclic PPAP core in a single step from their stable aromatic precursors. The first syntheses of 13,14-didehydroxyisogarcinol and garcimultiflorone A stereoisomers are reported in six steps from a commercially available phloroglucinol. Lewis acid-controlled, diastereoselective cationic oxycyclizations enabled asymmetric syntheses of (-)-6-epi-13,14-didehydroxyisogarcinol and (+)-30-epi-13,14-didehydroxyisogarcinol. A similar strategy enabled production of the meso-derived isomers (+/-)-6,30- epi-13,14-didehydroxyisogarcinol and (+/-)-6,30-epi -garcmultiflorone A. A convenient strategy for gram scale synthesis of these stereoisomers was developed utilizing diastereomer separation at a later stage in the synthesis that minimized the number of necessary synthetic operations to access all possible stereoisomers. Finally, we report cationic rearrangements of dearomatized acylphloroglucinols leading to the formation of unprecedented PPAP scaffolds. A novel type A [3.3.1]-bicyclic PPAP was produced as a major product and the structure confirmed by X-ray crystallographic

  18. The diversity in thermal behavior of novel catanionic cholates: The dominant effect of quaternary ammonium centers

    International Nuclear Information System (INIS)

    Mihelj, Tea; Vojta, Danijela; Tomašić, Vlasta

    2014-01-01

    Graphical abstract: - Highlights: • Quaternary ammonium cholates characterized as crystal smectics at room temperature. • The domination of quaternary ammonium center seen through diverse thermal behavior. • Thermal changes of cholates keto–enol balance results with prevalence of one form. • Polynomial regression of isotropisation temperatures vs. dodecyl chain number. • Linear descending trend of isotropisation temperatures with higher headgroup number. - Abstract: The thermal behavior of novel catanionic compounds based on cholate anion was examined. The study explains the effect of the raising dodecyl chain number, as well as of the raising headgroup number in quaternary ammonium salts on their physico-chemical properties. The examined samples are crystal smectic phases at room temperature. Their rich and diverse thermal behavior is seen through polymorphic phase transitions, thermotropic mesomorphism of smectic nature and in some cases, kinetically managed crystallization that lasts in days. The changes of the cholates keto–enol isomer balance during thermal treatment are obtained. For both groups of samples temperatures of isotropisation and the thermodynamic parameters follow polynomial regression. Introduction of the new dodecyl chain leads to more ordered structure, while implementation the new headgroup leads to advanced polymer-like structure. The obtained results demonstrate an effort for getting and controlling the regularity of the physico-chemical and thermotropic properties for new compounds by systematic changing of cationic part of the molecule. These informations could provide in the future the easiest way for selection of potentially new and targeted applicable materials

  19. The diversity in thermal behavior of novel catanionic cholates: The dominant effect of quaternary ammonium centers

    Energy Technology Data Exchange (ETDEWEB)

    Mihelj, Tea, E-mail: tmihelj@irb.hr [Department of Physical Chemistry, Ruđer Bošković Institute, POB 180, HR-10002 Zagreb (Croatia); Vojta, Danijela [Department of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, POB 180, HR-10002 Zagreb (Croatia); Tomašić, Vlasta [Department of Physical Chemistry, Ruđer Bošković Institute, POB 180, HR-10002 Zagreb (Croatia)

    2014-05-01

    Graphical abstract: - Highlights: • Quaternary ammonium cholates characterized as crystal smectics at room temperature. • The domination of quaternary ammonium center seen through diverse thermal behavior. • Thermal changes of cholates keto–enol balance results with prevalence of one form. • Polynomial regression of isotropisation temperatures vs. dodecyl chain number. • Linear descending trend of isotropisation temperatures with higher headgroup number. - Abstract: The thermal behavior of novel catanionic compounds based on cholate anion was examined. The study explains the effect of the raising dodecyl chain number, as well as of the raising headgroup number in quaternary ammonium salts on their physico-chemical properties. The examined samples are crystal smectic phases at room temperature. Their rich and diverse thermal behavior is seen through polymorphic phase transitions, thermotropic mesomorphism of smectic nature and in some cases, kinetically managed crystallization that lasts in days. The changes of the cholates keto–enol isomer balance during thermal treatment are obtained. For both groups of samples temperatures of isotropisation and the thermodynamic parameters follow polynomial regression. Introduction of the new dodecyl chain leads to more ordered structure, while implementation the new headgroup leads to advanced polymer-like structure. The obtained results demonstrate an effort for getting and controlling the regularity of the physico-chemical and thermotropic properties for new compounds by systematic changing of cationic part of the molecule. These informations could provide in the future the easiest way for selection of potentially new and targeted applicable materials.

  20. Ligand-Enabled γ-C–H Olefination and Carbonylation: Construction of β-Quaternary Carbon Centers

    Science.gov (United States)

    2015-01-01

    Monoselective γ-C–H olefination and carbonylation of aliphatic acids has been accomplished by using a combination of a quinoline-based ligand and a weakly coordinating amide directing group. The reaction provides a new route for constructing richly functionalized all-carbon quaternary carbon centers at the β-position of aliphatic acids. PMID:24666182

  1. LFG-500, a newly synthesized flavonoid, attenuates lipopolysaccharide-induced acute lung injury and inflammation in mice.

    Science.gov (United States)

    Li, Chenglin; Yang, Dan; Cao, Xin; Wang, Fan; Jiang, Haijing; Guo, Hao; Du, Lei; Guo, Qinglong; Yin, Xiaoxing

    2016-08-01

    Acute lung injury (ALI) often causes significant morbidity and mortality worldwide. Improved treatment and effective strategies are still required for ALI patients. Our previous studies demonstrated that LFG-500, a novel synthesized flavonoid, has potent anti-cancer activities, while its anti-inflammatory effect has not been revealed. In the present study, the in vivo protective effect of LFG-500 on the amelioration of lipopolysaccharide (LPS)-induced ALI and inflammation was detected. LFG-500 attenuated LPS-induced histological alterations, suppressed the infiltration of inflammatory cells in lung tissues and bronchoalveolar lavage fluid, as well as inhibited the secretion of several inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6 in lung tissues after LPS challenge. In addition, the in vitro effects and mechanisms were studied in LPS stimulated RAW 264.7 cells and THP-1 cells. LFG-500 significantly decreased the secretion and expression of TNF-α, IL-1β, and IL-6 through inhibiting the transcriptional activation of NF-κB. Moreover, overexpression of NF-κB p65 reversed the inhibitory effect of LFG-500 on LPS-induced NF-κB activation and inflammatory cytokine secretion. Further elucidation of the mechanism revealed that p38 and JNK MAPK pathways were involved in the anti-inflammation effect of LFG-500, through which LFG-500 inhibited the classical IKK-dependent pathway and led to inactivation of NF-κB. More importantly, LFG-500 suppressed the expression and nuclear localization of NF-κB in LPS-induced ALI mice. Taken together, these results demonstrated that LFG-500 could attenuate LPS-induced ALI and inflammation by suppressing NF-κB activation, which provides new evidence for the anti-inflammation activity of LFG-500. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Synthesis and crystal structure of the quaternary compound AgFe{sub 2}GaTe{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, Gerzon E., E-mail: gerzon@ula.ve [Laboratorio de Cristalografía, Departamento de Química, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101 (Venezuela, Bolivarian Republic of); Quintero, Eugenio; Tovar, Rafael; Grima-Gallardo, Pedro; Quintero, Miguel [Centro de Estudio de Semiconductores, Departamento de Física, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101 (Venezuela, Bolivarian Republic of)

    2014-11-15

    Highlights: • New quaternary compound. • Synthesis from solid state reaction. • Crystal structure. • Rietveld refinement. - Abstract: The crystal structure of the quaternary compound AgFe{sub 2}GaTe{sub 4}, belonging to the system I–II{sub 2}–III–VI{sub 4}, was characterized by Rietveld refinement using X-ray powder diffraction data. The powder pattern was composed by 84.5% of the principal phase AgFe{sub 2}GaTe{sub 4} and 15.5% of the secondary phase FeTe. This material crystallizes with stannite structure in the tetragonal space group I-42m (N° 121), Z = 2, unit cell parameters a = 6.3409(2) Å, c = 12.0233(4) Å, V = 483.42(3) Å{sup 3}, and is isostructural with CuFe{sub 2}InSe{sub 4}.

  3. Southern Dobrogea coastal potable water sources and Upper Quaternary Black Sea level changes

    Science.gov (United States)

    Caraivan, Glicherie; Stefanescu, Diana

    2013-04-01

    Southern Dobrogea is a typical geologic platform unit, placed in the south-eastern part of Romania, with a Pre-Cambrian crystalline basement and a Paleozoic - Quaternary sedimentary cover. It is bordered to the north by the Capidava - Ovidiu fault and by the Black Sea to the east. A regional WNW - ESE and NNE - SSW fault system divides the Southern Dobrogea structure in several tectonic blocks. Four drinking water sources have been identified: surface water, phreatic water, medium depth Sarmatian aquifer, and deep Upper Jurassic - Lower Cretaceous aquifer. Surface water sources are represented by several springs emerged from the base of the loess cliff, and a few small rivers, barred by coastal beaches. The phreatic aquifer develops at the base of the loess deposits, on the impervious red clay, overlapping the Sarmatian limestones. The medium depth aquifer is located in the altered and karstified Sarmatian limestones, and discharges into the Black Sea. The Sarmatian aquifer is unconfined where covered by silty loess deposits, and locally confined, where capped by clayey loess deposits. The aquifer is supplied from the Pre-Balkan Plateau. The Deep Upper Jurassic - Lower Cretaceous aquifer, located in the limestone and dolomite deposits, is generally confined and affected by the regional WNW - ESE and NNE - SSW fault system. In the south-eastern Dobrogea, the deep aquifer complex is separated from the Sarmatian aquifer by a Senonian aquitard (chalk and marls). The natural boundary of the Upper Jurassic - Lower Cretaceous aquifer is the Capidava - Ovidiu Fault. The piezometric heads show that the Upper Jurassic - Lower Cretaceous aquifer is supplied from the Bulgarian territory, where the Upper Jurassic deposits crop out. The aquifer discharges into the Black Sea to the east and into Lake Siutghiol to the northeast. The cyclic Upper Quaternary climate changes induced drastic remodeling of the Black Sea level and the corresponding shorelines. During the Last Glacial

  4. Linking micro- and macroevolutionary perspectives to evaluate the role of Quaternary sea-level oscillations in island diversification.

    Science.gov (United States)

    Papadopoulou, Anna; Knowles, L Lacey

    2017-12-01

    With shifts in island area, isolation, and cycles of island fusion-fission, the role of Quaternary sea-level oscillations as drivers of diversification is complex and not well understood. Here, we conduct parallel comparisons of population and species divergence between two island areas of equivalent size that have been affected differently by sea-level oscillations, with the aim to understand the micro- and macroevolutionary dynamics associated with sea-level change. Using genome-wide datasets for a clade of seven Amphiacusta ground cricket species endemic to the Puerto Rico Bank (PRB), we found consistently deeper interspecific divergences and higher population differentiation across the unfragmented Western PRB, in comparison to the currently fragmented Eastern PRB that has experienced extreme changes in island area and connectivity during the Quaternary. We evaluate alternative hypotheses related to the microevolutionary processes (population splitting, extinction, and merging) that regulate the frequency of completed speciation across the PRB. Our results suggest that under certain combinations of archipelago characteristics and taxon traits, the repeated changes in island area and connectivity may create an opposite effect to the hypothesized "species pump" action of oscillating sea levels. Our study highlights how a microevolutionary perspective can complement current macroecological work on the Quaternary dynamics of island biodiversity. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  5. Measurements and modeling of quaternary (liquid + liquid) equilibria for mixtures of (methanol or ethanol + water + toluene + n-dodecane)

    International Nuclear Information System (INIS)

    Mohammad Doulabi, F.S.; Mohsen-Nia, M.; Modarress, H.

    2006-01-01

    The extraction of aromatic compound toluene from alkane, dodecane, by mixed solvents (water + methanol) (water + ethanol) and (methanol + ethanol) have been studied by (liquid + liquid) equilibrium (LLE) measurements at three temperatures (298.15, 303.15, and 313.15) K and ambient pressure. The compositions of liquid phases at equilibrium were determined by gas liquid chromatography. The experimental tie-line data for three quaternary mixtures of {(water + methanol) + toluene + dodecane}, {(water + ethanol) + toluene + dodecane}, and {(methanol + ethanol) + toluene + dodecane} are presented. The experimental quaternary LLE data have been satisfactorily correlated by using the UNIQUAC and NRTL activity coefficient models. The parameters of the models have been evaluated and presented. The tie-line data of the studied quaternary mixtures also were correlated using the Hand method. The partition coefficients and the selectivity factor of solvent are calculated and compared for the three mixed solvents. The comparisons indicate that the selectivity factor for mixed solvent (methanol + ethanol) is higher than the other two mixed solvents at the three studied temperatures. However, considering the temperature variations of partition coefficients of toluene in two liquid phases at equilibrium, an optimum temperature may be obtained for an efficient extraction of toluene from dodecane by the mixed solvents

  6. Multi-process Late Quaternary landscape evolution modelling reveals lags in climate response over small spatial scales

    NARCIS (Netherlands)

    Temme, A.J.A.M.; Veldkamp, A.

    2009-01-01

    Landscapes evolve in complex, non-linear ways over Quaternary timespans. Integrated geomorphological field studies usually yield plausible hypotheses about timing and impact of process activity. Landscape Evolution Models (LEMs) have the potential to test and falsify these landscape evolution

  7. Natural responses to Quaternary climatic change in the Nevada Test Site region

    International Nuclear Information System (INIS)

    Gibson, J.D.

    1993-01-01

    Migration of hazardous contaminants within geologic settings depends on natural processes. Climatic fluctuations can affect the magnitudes and rates of many of these processes. In any long-term environmental evaluation of natural processes, responses to climatic change must be considered. Four generalized categories of natural responses to Quaternary climatic change are recognized for the Nevada Test Site (NTS) region of southwestern Nevada and adjacent California: (1) biologic, (2) geomorphic, (3) hydrologic (including surface and subsurface) and (4) pedologic/diagenetic. Specific examples that correspond to the four categories illustrate the broad range of complex natural processes the are affected by climatic change. These responses dictate the potential effects of climatic change on contaminant transport, effects that are being examined by existing and planned environmental-restoration and waste-management programs within the region. Regulatory requirements for many of these programs include long-term (>10,000-year) waste isolation because of radiologic components. The purpose here is not to be exhaustive in documenting all known natural responses to climatic change in the NTS region, but rather to give a flavor of the scope of interdisciplinary and interrelated fields of Quaternary science that must be considered in evaluating the possible effects of climatic change on long-term environmental programs

  8. A newly developed Fe-doped calcium sulfide nanoparticles with magnetic property for cancer hyperthermia

    Science.gov (United States)

    Wu, Steven Yueh-Hsiu; Tseng, Ching-Li; Lin, Feng-Huei

    2010-05-01

    In this study, a magnetic iron-doped calcium sulfide (Fe-CaS) nanoparticle was newly developed and studied for the purpose of hyperthermia due to its promising magnetic property, adequate biodegradation rate, and relatively good biocompatibility. Fe-CaS nanoparticles were synthesized by a wet chemical co-precipitation process with heat treatment in a N2 atmosphere, and were subsequently cooled in N2 and exposed to air at a low temperature. The crystal structure of the Fe-CaS nanoparticles was similar to that of the CaS, which was identified by an X-ray diffractometer (XRD). The particle size was less than 40 nm based on a Debye-Scherrer equation and transmission electron microscope (TEM) examination. Magnetic properties obtained from the SQUID magnetometer demonstrated that the synthesized CaS was a diamagnetic property. Once the Fe ions were doped, the synthesized Fe-CaS converted into paramagnetism which showed no hysteresis loop. Having been heated above 600 °C in N2, the Fe-CaS showed a promising magnetic property to produce enough energy to increase the temperature for hyperthermia. 10 mg/ml of the Fe-CaS was able to generate heat to elevate the media temperature over 42.5 °C within 6 min. The area of the hysteresis loop increased with the increasing of the treated temperature, especially at 800 °C for 1 h. This is because more Fe ions replaced Ca ions in the lattice at the higher heat treatment temperature. The heat production was also increasing with the increasing of heat treatment temperature, which resulted in an adequate specific absorption ratio (SAR) value, which was found to be 45.47 W/g at 37 °C under an alternative magnetic field of f = 750 KHz , H = 10 Oe. The in vitro biocompatibility test of the synthesized Fe-CaS nanoparticles examined by the LDH assay showed no cytotoxicity to 3T3 fibroblast. The result of in vitro cell hyperthermia shows that under magnetic field the Fe-CaS nanoparticles were able to generate heat and kill the CT-26 cancer

  9. A newly developed Fe-doped calcium sulfide nanoparticles with magnetic property for cancer hyperthermia

    International Nuclear Information System (INIS)

    Wu, Steven Yueh-Hsiu; Tseng, Ching-Li; Lin, Feng-Huei

    2010-01-01

    In this study, a magnetic iron-doped calcium sulfide (Fe-CaS) nanoparticle was newly developed and studied for the purpose of hyperthermia due to its promising magnetic property, adequate biodegradation rate, and relatively good biocompatibility. Fe-CaS nanoparticles were synthesized by a wet chemical co-precipitation process with heat treatment in a N 2 atmosphere, and were subsequently cooled in N 2 and exposed to air at a low temperature. The crystal structure of the Fe-CaS nanoparticles was similar to that of the CaS, which was identified by an X-ray diffractometer (XRD). The particle size was less than 40 nm based on a Debye-Scherrer equation and transmission electron microscope (TEM) examination. Magnetic properties obtained from the SQUID magnetometer demonstrated that the synthesized CaS was a diamagnetic property. Once the Fe ions were doped, the synthesized Fe-CaS converted into paramagnetism which showed no hysteresis loop. Having been heated above 600 o C in N 2 , the Fe-CaS showed a promising magnetic property to produce enough energy to increase the temperature for hyperthermia. 10 mg/ml of the Fe-CaS was able to generate heat to elevate the media temperature over 42.5 o C within 6 min. The area of the hysteresis loop increased with the increasing of the treated temperature, especially at 800 o C for 1 h. This is because more Fe ions replaced Ca ions in the lattice at the higher heat treatment temperature. The heat production was also increasing with the increasing of heat treatment temperature, which resulted in an adequate specific absorption ratio (SAR) value, which was found to be 45.47 W/g at 37 o C under an alternative magnetic field of f = 750 KHz, H = 10 Oe. The in vitro biocompatibility test of the synthesized Fe-CaS nanoparticles examined by the LDH assay showed no cytotoxicity to 3T3 fibroblast. The result of in vitro cell hyperthermia shows that under magnetic field the Fe-CaS nanoparticles were able to generate heat and kill the CT-26

  10. Quaternary geologic map of the Austin 4° x 6° quadrangle, United States

    Science.gov (United States)

    State compilations by Moore, David W.; Wermund, E.G.; edited and integrated by Moore, David W.; Richmond, Gerald Martin; Christiansen, Ann Coe; Bush, Charles A.

    1993-01-01

    This map is part of the Quaternary Geologic Atlas of the United States (I-1420). It was first published as a printed edition in 1993. The geologic data have now been captured digitally and are presented here along with images of the printed map sheet and component parts as PDF files. The Quaternary Geologic Map of the Austin 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the Earth. They make up the ground on which we walk, the dirt in which we dig foundations, and the soil in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. In recent years, surficial deposits and materials have become the focus of much interest by scientists, environmentalists, governmental agencies, and the general public. They are the foundations of ecosystems, the materials that support plant growth and animal habitat, and the materials through which travels much of the water required for our agriculture, our industry, and our general well being. They also are materials that easily can become contaminated by pesticides, fertilizers, and toxic wastes. In this context, the value of the surficial geologic map is evident.

  11. Composites comprising biologically-synthesized nanomaterials

    Science.gov (United States)

    Curran, Seamus; Dias, Sampath; Blau, Werner; Wang, Jun; Oremland, Ronald S; Baesman, Shaun

    2013-04-30

    The present disclosure describes composite materials containing a polymer material and a nanoscale material dispersed in the polymer material. The nanoscale materials may be biologically synthesized, such as tellurium nanorods synthesized by Bacillus selenitireducens. Composite materials of the present disclosure may have optical limiting properties and find use in optical limiting devices.

  12. Thermoluminescence properties of Li2B4O7:Cu, B phosphor synthesized using solution combustion technique

    Science.gov (United States)

    Ozdemir, A.; Altunal, V.; Kurt, K.; Depci, T.; Yu, Y.; Lawrence, Y.; Nur, N.; Guckan, V.; Yegingil, Z.

    2017-12-01

    To determine the effects of various concentrations of the activators copper (Cu) and boron (B) on the thermoluminescence (TL) properties of lithium tetraborate, the phosphor was first synthesized and doped with five different concentrations of copper (0.1-0.005 wt%) using solution combustion method. 0.01 wt% Cu was the concentration which showed the most significant increase in the sensitivity of the phosphor. The second sort of Li2B4O7:Cu material was prepared by adding B (0.001-0.03 wt%) to it. The newly developed copper-boron activated lithium tetraborate (Li2B4O7:Cu, B) material with 0.01 wt% Cu and 0.001 wt% B impurity concentrations was shown to have promise as a TL phosphor. The material formation was examined using powder x-Ray Diffraction (XRD) analysis and Scanning Electron Microscope (SEM) imaging. Fourier Transform Infrared (FT-IR) spectrum of the synthesized polycrystalline powder sample was also recorded. The TL glow curves were analyzed to determine various dosimetric characteristics of the synthesized luminophosphors. The dose response increased in a ;linear; way with the beta-ray exposure between 0.1-20 Gy, a dose range being interested in medical dosimetry. The response with changing photon and electron energy was studied. The rate of decay of the TL signal was investigated both for dark storage and under direct sunlight. Li2B4O7:Cu, B showed no individual variation of response in 9 recycling measurements. The fluorescence spectrum was determined. The kinetic parameters were estimated by different methods and the results discussed. The studied properties of synthesized Li2B4O7:Cu, B were found all favorable for dosimetric purposes.

  13. Electronic, magnetic and transport properties of quaternary (Cu,Ni)MnSb alloys

    Czech Academy of Sciences Publication Activity Database

    Kudrnovský, Josef; Drchal, Václav; Máca, František; Turek, Ilja

    2008-01-01

    Roč. 88, 18-20 (2008), s. 2739-2746 ISSN 1478-6435 R&D Projects: GA ČR GA202/07/0456; GA MŠk OC 150; GA AV ČR IAA100100616 Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z20410507 Keywords : density functional theory * exchange interaction * effective Heisenberg model * magnetic disorder * Curie temperature * quaternary Heusler alloys Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.384, year: 2008

  14. Quaternary continental deposits in north of Uruguay: stratigraphy and paleontology

    International Nuclear Information System (INIS)

    Goso Aguilar, C.; Ubilla, M.

    2004-01-01

    Conglomeradic and sandstones lithofacies corresponding to fluvial and alluvial environments were recognized. These sediments partially belong to the quaternary Mataojos Formation. A discordant contact with the upper pelitic deposits identified with the Sopas Formation was detected. This paper deals with sedimentological and stratigraphical considerations in order to explain the sedimentary processes during the genesis of these stratigraphic sections as well as to begin a lithostratigraphical discussion about the operability of those units. In turn, chronologic and paleoenvironment comments are provided taken into account vertebrates fossils and tools to perform chronocorrelation with southern sedimentological units of Uruguay [es

  15. Geophysical Characterization of the Quaternary-Cretaceous Contact Using Surface Resistivity Methods in Franklin and Webster Counties, South-Central Nebraska

    Science.gov (United States)

    Teeple, Andrew; Kress, Wade H.; Cannia, James C.; Ball, Lyndsay B.

    2009-01-01

    To help manage and understand the Platte River system in Nebraska, the Platte River Cooperative Hydrology Study (COHYST), a group of state and local governmental agencies, developed a regional ground-water model. The southern boundary of this model lies along the Republican River, where an area with insufficient geologic data immediately north of the Republican River led to problems in the conceptualization of the simulated flow system and to potential problems with calibration of the simulation. Geologic descriptions from a group of test holes drilled in south-central Nebraska during 2001 and 2002 indicated a possible hydrologic disconnection between the Quaternary-age alluvial deposits in the uplands and those in the Republican River lowland. This disconnection was observed near a topographic high in the Cretaceous-age Niobrara Formation, which is the local bedrock. In 2003, the U.S. Geological Survey, in cooperation with the COHYST, collected surface geophysical data near these test holes to better define this discontinuity. Two-dimensional imaging methods for direct-current resistivity and capacitively coupled resistivity were used to define the subsurface distribution of resistivity along several county roads near Riverton and Inavale, Nebraska. The relation between the subsurface distribution of resistivity and geology was defined by comparing existing geologic descriptions of test holes to surface-geophysical resistivity data along two profiles and using the information gained from these comparisons to interpret the remaining four profiles. In all of the resistivity profile sections, there was generally a three-layer subsurface interpretation, with a resistor located between two conductors. Further comparison of geologic data with the geophysical data and with surficial features was used to identify a topographic high in the Niobrara Formation near the Franklin Canal which was coincident with a resistivity high. Electrical properties of the Niobrara

  16. Controls on Cyclic Formation of Quaternary Early Diagenetic Dolomite

    Science.gov (United States)

    McCormack, J.; Bontognali, T. R. R.; Immenhauser, A.; Kwiecien, O.

    2018-04-01

    The origin of sedimentary dolomite and the factors that control its formation within the geological record remain speculative. In most models, dolomite formation is linked to evaporative conditions, high water temperature, increasing Mg/Ca ratio, increasing alkalinity, and high amounts of biomass. Here we challenge these archetypal views, by documenting a case example of Quaternary dolomite which formed in Lake Van at constantly low temperature (stress, resulting from reventilation of the water-sediment interface. Independently from the validity of this hypothesis, our results call for a reevaluation of the paleoenvironmental conditions often invoked for early diagenetic dolomite-rich intervals within sedimentary sequences and for caution when interpreting time series of subrecent lacustrine carbonates.

  17. Post-translational Introduction of D-Alanine into Ribosomally Synthesized Peptides by the Dehydroalanine Reductase NpnJ.

    Science.gov (United States)

    Yang, Xiao; van der Donk, Wilfred A

    2015-10-07

    Ribosomally synthesized peptides are generally limited to L-amino acid building blocks. Given the advantageous properties of peptides containing D-amino acids such as stabilization of certain turns and against proteolytic degradation, methods to introduce D-stereocenters are valuable. Here we report the first in vitro reconstitution and characterization of a dehydrogenase that carries out the asymmetric reduction of dehydroalanine. NpnJA reduces dehydroalanine to D-Ala using NAPDH as cosubstrate. The enzyme displays high substrate tolerance allowing introduction of D-Ala into a range of non-native substrates. In addition to the in vitro reactions, we describe five examples of using Escherichia coli as biosynthetic host for D-alanine introduction into ribosomal peptides. A deuterium-label-based coupled-enzyme assay was used to rapidly determine the stereochemistry of the newly installed alanine.

  18. Mechanism of Osmotic Activation of the Quaternary Ammonium Compound Transporter (QacT) of Lactobacillus plantarum

    NARCIS (Netherlands)

    Glaasker, Erwin; Heuberger, Esther H.M.L.; Konings, Wil N.; Poolman, Bert

    1998-01-01

    The accumulation of quaternary ammonium compounds in Lactobacillus plantarum is mediated via a single transport system with a high affinity for glycine betaine (apparent Km of 18 μM) and carnitine and a low affinity for proline (apparent Km of 950 μM) and other analogues. Mutants defective in the

  19. Evidences of late quaternary neotectonic activity and sea-level changes along the western continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Veerayya, M.; Thamban, M.; Wagle, B.G.

    The offshore data on sea-level changes along the western margin of India have been reviewed and evidences of Late Quaternary neotectonic activity and subsidence are documented, based on the diagenetic textures of limestones from deeper submarine...

  20. Characterization of Quaternary and suspected Quaternary faults, regional studies, Nevada and California

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, R.E.; Bucknam, R.C.; Crone, A.J.; Haller, K.M.; Machette, M.N.; Personius, S.F.; Barnhard, T.P.; Cecil, M.J.; Dart, R.L.

    1995-12-31

    This report presents the results of geologic studies that help define the Quaternary history of selected faults in the region around Yucca Mountain, Nevada. These results are relevant to the seismic-design basis of a potential nuclear waste repository at Yucca Mountain. The relevancy is based, in part, on a need for additional geologic data that became apparent in ongoing studies that resulted in the identification of 51 relevant and potentially relevant individual and compound faults and fault zones in the 100-km-radius region around the Yucca Mountain site. Geologic data used to characterize the regional faults and fault zones as relevant or potentially relevant seismic sources includes age and displacement information, maximum fault lengths, and minimum distances between the fault and the Yucca Mountain site. For many of the regional faults, no paleoseismic field studies have previously been conducted, and age and displacement data are sparse to nonexistent. In November 1994, the Branch of Earthquake and Landslide Hazards entered into two Memoranda of Agreement with the Yucca Mountain Project Branch to conduct field reconnaissance, analysis, and interpretation of six relevant and six potentially relevant regional faults. This report describes the results of study of those faults exclusive of those in the Pahrump-Stewart Valley-Ash Meadows-Amargosa Valley areas. We also include results of a cursory study of faults on the west flank of the Specter Range and in the northern part of the Last Chance Range. A four-phase strategy was implemented for the field study.

  1. A glimpse of the Quaternary monsoon history from India and adjoining seas

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswat, R.; Nigam, R.; Correge, T.

    /plain; charset=UTF-8 1    Author version: Palaeogeogr. Palaeoclimatol. Palaeoecol., vol.397; 2014; 1-6 A glimpse of the Quaternary monsoon history from India and adjoining seas Rajeev Saraswat1, Rajiv Nigam1, Thierry Correge2 1 National... and radionuclide (210Pb) analyses to understand past environmental changes from the sediment cores collected from mudflat regions of central west coast of India. A significant shift in sediment characteristics is observed post 1980, probably in response...

  2. Characterisation and discrimination of various types of lac resin using gas chromatography mass spectrometry techniques with quaternary ammonium reagents.

    Science.gov (United States)

    Sutherland, K; del Río, J C

    2014-04-18

    A variety of lac resin samples obtained from artists' suppliers, industrial manufacturers, and museum collections were analysed using gas chromatography mass spectrometry (GCMS) and reactive pyrolysis GCMS with quaternary ammonium reagents. These techniques allowed a detailed chemical characterisation of microgram-sized samples, based on the detection and identification of derivatives of the hydroxy aliphatic and cyclic (sesquiterpene) acids that compose the resin. Differences in composition could be related to the nature of the resin, e.g. wax-containing (unrefined), bleached, or aged samples. Furthermore, differences in the relative abundances of aliphatic hydroxyacids appear to be associated with the biological source of the resin. The diagnostic value of newly characterised lac components, including 8-hydroxyacids, is discussed here for the first time. Identification of derivatised components was aided by AMDIS deconvolution software, and discrimination of samples was enhanced by statistical evaluation of data using principal component analysis. The robustness of the analyses, together with the minimal sample size required, make these very powerful approaches for the characterisation of lac resin in museum objects. The value of such analyses for enhancing the understanding of museum collections is illustrated by two case studies of objects in the collection of the Philadelphia Museum of Art: a restorer's varnish on a painting by Luca Signorelli, and a pictorial inlay in an early nineteenth-century High Chest by George Dyer. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Numerical modelling of Quaternary terrace staircase formation in the Ebro foreland basin, southern Pyrenees, NE Iberia

    NARCIS (Netherlands)

    van Balen, R.T.; Stange, K.M.; Cloetingh, S.A.P.L.; Garcia-Castellanos, D.

    2016-01-01

    The southern foreland basin of the Pyrenees (Ebro basin) is an exorheic drainage basin since Late Miocene times. Remnants of an early exorheic Ebro drainage system are not preserved, but morphology provides evidence for the Pliocene–Quaternary drainage development. The incision history of the Ebro

  4. Impact of Quaternary climatic changes and interspecific competition on the demographic history of a highly mobile generalist carnivore, the coyote.

    Science.gov (United States)

    Koblmüller, Stephan; Wayne, Robert K; Leonard, Jennifer A

    2012-08-23

    Recurrent cycles of climatic change during the Quaternary period have dramatically affected the population genetic structure of many species. We reconstruct the recent demographic history of the coyote (Canis latrans) through the use of Bayesian techniques to examine the effects of Late Quaternary climatic perturbations on the genetic structure of a highly mobile generalist species. Our analysis reveals a lack of phylogeographic structure throughout the range but past population size changes correlated with climatic changes. We conclude that even generalist carnivorous species are very susceptible to environmental changes associated with climatic perturbations. This effect may be enhanced in coyotes by interspecific competition with larger carnivores.

  5. Coating of adenovirus type 5 with polymers containing quaternary amines prevents binding to blood components

    Czech Academy of Sciences Publication Activity Database

    Šubr, Vladimír; Kostka, Libor; Selby-Milic, T.; Fisher, K.; Ulbrich, Karel; Seymour, W.; Carlisle, R. C.

    2009-01-01

    Roč. 135, č. 2 (2009), s. 152-158 ISSN 0168-3659 R&D Projects: GA AV ČR KJB400500803 EU Projects: European Commission(XE) 512087 - GIANT Institutional research plan: CEZ:AV0Z40500505 Keywords : quaternary ammonium * HPMA * adenovirus Subject RIV: CD - Macromolecular Chemistry Impact factor: 5.949, year: 2009

  6. Antibacterial Activity of Orthodontic Cement Containing Quaternary Ammonium Polyethylenimine Nanoparticles Adjacent to Orthodontic Brackets

    OpenAIRE

    Eldad Sharon; Revital Sharabi; Adi Eden; Asher Zabrovsky; Gilad Ben-Gal; Esi Sharon; Yoav Pietrokovski; Yael Houri-Haddad; Nurit Beyth

    2018-01-01

    Enamel demineralization is a common problem found in patients using orthodontic devices, such as orthodontic braces. It was found that Streptoccocus mutans growth increases adjacent to orthodontic devices, which may result in caries development. Incorporated antibacterial quaternary ammonium polyethylenimine (QPEI) nanoparticles were previously shown to be highly efficacious against various bacteria. Combining antibacterial materials in orthodontic cement may be advantageous to prevent bacter...

  7. Quaternary ammonium compounds – New occupational hazards

    Directory of Open Access Journals (Sweden)

    Agnieszka Lipińska-Ojrzanowska

    2014-10-01

    Full Text Available Quaternary ammonium compounds (QACs, quats belong to organic ionic chemical agents which display unique properties of both surfactants and disinfectants. Their wide distribution in the work environment and also in private households brings about new occupational hazards. This paper reviews reports about the health effects of QACs. QACs could play a role of sensitizers and irritants to the skin and mucous membranes. It is suspected that particular QACs can display an immunologic crossreactivity between each other and with other chemical compounds containing ammonium ion, such as muscle relaxants widely used in anesthesia. They may promote the development of airway allergy, however, the background mechanisms are still unclear and need to be further investigated. Until now, a few cases of occupational asthma induced by QACs have been described and their involvement in contact dermatitis has been documented. The possibility of anaphylaxis due to QACs cannot be excluded as well. Med Pr 2014;65(5:675–682

  8. U-series disequilibrium dating of Quaternary carbonates

    International Nuclear Information System (INIS)

    Stirling, C.

    2006-01-01

    One of the key dating methods used in paleoclimate research utilizes the natural radioactive decay of uranium to thorium in archives containing U-bearing minerals, such as the calcium carbonate forming the skeletons of fossil corals and speleothems. More specifically, this chronometer, commonly referred to as the U-series dating method, is based on the decay of 238 U to its longest-lived intermediate daughters, 234 U and 230 Th, and subsequent decay through to stable isotopes of Pb. It is the respective 250,000 and 75,000 year half-lives of these daughter isotopes, which make the U-series system particularly useful for dating Quaternary climate events spanning the last 600,000 years of Earth's history. The U-series thus bridges the gap between the ∼45,000 year upper limit of conventional radiocarbon dating and the ∼200,000 year lower limit of K-Ar and 40 Ar- 39 Ar dating. 2 refs., 5 figs

  9. Geochemical evidence for the origin of late Quaternary loess in central Alaska

    Science.gov (United States)

    Muhs, D.R.; Budahn, J.R.

    2006-01-01

    Loess is extensive in central Alaska, but there are uncertainties about its source and the direction of paleo-winds that deposited it. Both northerly and southerly winds have been inferred. The most likely sources of loess are the Tanana River (south), the Nenana River (southeast), and the Yukon River (north). Late Quaternary loess in central Alaska has immobile trace-element compositions (Cr/Sc, Th/Ta, Th/ Sc, Th/U, Eu/Eu*, GdN/YbN) that indicate derivation mostly from the Tanana River. However, other ratios (As/Sb, Zr/Hf, LaN/YbN) and quantitative modeling indicate that the Yukon River was also a source. During the last glacial period, there may have been a longer residence time of the Siberian and Canadian high-pressure cells, along with a strengthened Aleutian low-pressure cell. This would have generated regional-scale northeasterly winds and explains derivation of loess from the Yukon River. However, superim-posed upon this synoptic-scale circulation, there may have been strong, southerly katabatic winds from expanded glaciers on the northern flank of the Alaska Range. These winds could have provided eolian silt from the Tanana River. Yukon River and Tanana River sediments are highly calcareous, whereas Fairbanks-area loess is not. This suggests that carbonate leaching in loess kept ahead of sedimentation and that late Quaternary loess in central Alaska was deposited relatively slowly. ?? 2006 NRC Canada.

  10. New quaternary thallium indium germanium selenide TlInGe2Se6: Crystal and electronic structure

    Science.gov (United States)

    Khyzhun, O. Y.; Parasyuk, O. V.; Tsisar, O. V.; Piskach, L. V.; Myronchuk, G. L.; Levytskyy, V. O.; Babizhetskyy, V. S.

    2017-10-01

    Crystal structure of a novel quaternary thallium indium germanium selenide TlInGe2Se6 was investigated by means of powder X-ray diffraction method. It was determined that the compound crystallizes in the trigonal space group R3 with the unit cell parameters a = 10.1798(2) Å, c = 9.2872(3) Å. The relationship with similar structures was discussed. The as-synthesized TlInGe2Se6 ingot was tested with X-ray photoelectron spectroscopy (XPS) and X-ray emission spectroscopy (XES). In particular, the XPS valence-band and core-level spectra were recorded for initial and Ar+ ion-bombarded surfaces of the sample under consideration. The XPS data allow for statement that the TlInGe2Se6 surface is rigid with respect to Ar+ ion-bombardment. Particularly, Ar+ ion-bombardment (3.0 keV, 5 min duration, ion current density fixed at 14 μA/cm2) did not cause substantial modifications of stoichiometry in topmost surface layers. Furthermore, comparison on a common energy scale of the XES Se Kβ2 and Ge Kβ2 bands and the XPS valence-band spectrum reveals that the principal contributions of the Se 4p and Ge 4p states occur in the upper and central portions of the valence band of TlInGe2Se6, respectively, with also their substantial contributions in other portions of the band. The bandgap energy of TlInGe2Se6 at the level of αg=103 cm-1 is equal to 2.38 eV at room temperature.

  11. Applicability of a dilute quaternary model in interpreting the thermodynamic properties of the Fe-Ni-Ta-N system

    International Nuclear Information System (INIS)

    Jayaganthan, R.; Hajra, J.P.

    1997-01-01

    Interaction parameter formalism is considered to be important for representation of the excess thermodynamic properties of multi-component systems. In the present article, the same method as adopted in their earlier article has been used for deducing the partials of the Quatenary System. The derivation of lnγ 1 , lnγ 2 , lnγ 3 and lnγ 4 of the quaternary system involves extensive summation of various infinite series pertaining to first order and quaternary parameters in order to preserve thermodynamic consistency. Although the derivation and consistency of the partials are described elsewhere, a brief outline of the latter with an emphasis of their applicability to the experimental data of the Fe-Ni-Ta-N system in the temperature range of 1,796--1,983K are presented

  12. Rapid visual detection of quaternary ammonium surfactants using citrate-capped silver nanoparticles (Ag NPs) based on hydrophobic effect.

    Science.gov (United States)

    Zheng, Li-Qing; Yu, Xiao-Dong; Xu, Jing-Juan; Chen, Hong-Yuan

    2014-01-01

    In this work, a rapid, sensitive and low-cost colorimetric method for detection of quaternary ammonium surfactants using citrate-capped silver nanoparticles (Ag NPs) was developed. The quaternary ammonium surfactants induce the aggregation of Ag NPs through the hydrophobic effect, which is a novel aggregation mechanism of Ag NPs. The addition of cationic surfactant results in color change of Ag NPs solution from yellow to red and finally to colorless, which is due to the broadening of the surface plasmon band. The color change was monitored using a UV-vis spectrophotometer. The LOD of different cationic surfactants was in the range of 0.5-5 µM. More importantly, this detection method was successfully utilized to the disinfectant residual sample. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved.

  13. Confidence in leadership among the newly qualified.

    Science.gov (United States)

    Bayliss-Pratt, Lisa; Morley, Mary; Bagley, Liz; Alderson, Steven

    2013-10-23

    The Francis report highlighted the importance of strong leadership from health professionals but it is unclear how prepared those who are newly qualified feel to take on a leadership role. We aimed to assess the confidence of newly qualified health professionals working in the West Midlands in the different competencies of the NHS Leadership Framework. Most respondents felt confident in their abilities to demonstrate personal qualities and work with others, but less so at managing or improving services or setting direction.

  14. Multiple ash layers in late Quaternary sediments from the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas-Pereira, M.B.L.; Nath, B.N.; Iyer, S.D.; Borole, D.V.; Parthiban, G.; Jijin, R.; Khedekar, V.D.

    to those originated from Toba, the age (>180 ka) of the shard-bearing sediments was different from the major Quaternary Toba eruptions namely Young, Middle and Old Toba Tuff (YTT, MTT and OTT) and other rhyolitic eruptions in the Indian Ocean. This fact.... 4. Discussion Prior to delving into the discussion it would be pertinent to clarify certain aspects that may have a bearing on the distribution, characteristics, composition, source and age of the volcanic horizons. The premises that we have...

  15. Deployment of an in-house designed training process in a quaternary care hospital.

    Science.gov (United States)

    Kumar, Ajit; Bhatia, Saurabh; Chiang, I-Jen

    2013-01-01

    Healthcare providers, such as doctors and nurses, have been famous for high resistance to change. A careful change management plan, particularly training process, is utmost necessary. A quaternary care hospital in India changed its system, from manual to Electronic Medical Record/Health Information System (EMR/HIS). The hospital management wanted to train its 4000 diverse end-users on the EMR/HIS in two months' time. This paper describes an in-house designed training process and its deployment in the given healthcare organizational settings. We designed a training process named DRIPDA. The training process was deployed to train 4000 end-users of EMR/HIS, in the quaternary care hospital. Various factors, such as methods and tools of training, constraints of trainees, trainers, and organization were considered while deploying the training process. The effectiveness of the DRIPDA was assessed using the Kirkpatrick model. End-users received training on the new system only in 25% of estimated time and 28% of the projected expense, without having any distraction in their usual workflow, or any productivity loss. We found that the DRIPDA training process could train all employees effectively and efficiently. A decent training process can help in managing the change, thereby reduce the training time and cost.

  16. Quaternary Geologic Map of the Lake Nipigon 4 Degrees x 6 Degrees Quadrangle, United States and Canada

    Science.gov (United States)

    Sado, Edward V.; Fullerton, David S.; Farrand, William R.; Edited and Integrated by Fullerton, David S.

    1994-01-01

    The Quaternary Geologic Map of the Lake Nipigon 4 degree x 6 degree Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. This map is a product of collaboration of the Ontario Geological Survey, the University of Michigan, and the U.S. Geological Survey, and is designed for both scientific and practical purposes. It was prepared in two stages. First, separate maps and map explanations were prepared by the compilers. Second, the maps were combined, integrated, and supplemented by the editor. Map unit symbols were revised to a uniform system of classification and the map unit descriptions were prepared by the editor from information received from the compilers and from additional sources listed under Sources of Information. Diagrams accompanying the map were prepared by the editor. For scientific purposes, the map differentiates Quaternary surficial deposits on the basis of lithology or composition, texture or particle size, structure, genesis, stratigraphic relationships, engineering geologic properties, and relative age, as shown on the correlation diagram and indicated in the map unit descriptions. Deposits of some constructional landforms, such as kame moraine deposits, are distinguished as map units. Deposits of

  17. Evaluation of drug-carrier interactions in quaternary powder mixtures containing perindopril tert-butylamine and indapamide.

    Science.gov (United States)

    Voelkel, Adam; Milczewska, Kasylda; Teżyk, Michał; Milanowski, Bartłomiej; Lulek, Janina

    2016-04-30

    Interactions occurring between components in the quaternary powder mixtures consisting of perindopril tert-butylamine, indapamide (active pharmaceutical ingredients), carrier substance and hydrophobic colloidal silica were examined. Two grades of lactose monohydrate: Spherolac(®) 100 and Granulac(®) 200 and two types of microcrystalline cellulose: M101D+ and Vivapur(®) 102 were used as carriers. We determined the size distribution (laser diffraction method), morphology (scanning electron microscopy) and a specific surface area of the powder particles (by nitrogen adsorption-desorption). For the determination of the surface energy of powder mixtures the method of inverse gas chromatography was applied. Investigated mixtures were characterized by surface parameters (dispersive component of surface energy, specific interactions parameters, specific surface area), work of adhesion and cohesion as well as Flory-Huggins parameter χ23('). Results obtained for all quaternary powder mixtures indicate existence of interactions between components. The strongest interactions occur for both blends with different types of microcrystalline cellulose (PM-1 and PM-4) while much weaker ones for powder mixtures with various types of lactose (PM-2 and PM-3). Published by Elsevier B.V.

  18. Quaternary-geological results and problems of the Gorleben project for final storage of radioactive waste

    International Nuclear Information System (INIS)

    Duphorn, K.

    1984-01-01

    The measured results and the ground-water flow models elaborated by the Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover, show that the ground-water flows relatively fast in the high-permeability quaternary sands and gravels of the Gorleben channel down to the caprock. This accounts for the current subrosion rate which has been determined to be up to 1 mm per annum, so that a subrosion volume of up to 10.000 m 3 a year is to be expected, which means that ground-water flow from the channel bottom to the soil surface is expected to take a period of only 600 up to 3700 years. These quaternary-hydrogeological results give reason to doubt whether the model of the geologic multi-barriers, according to which a protective function is attributed to the ''caprock barrier'', can really be applied. The results show that the ''salt-bed barrier'' at the Gorleben site is geologically unstable and endangered by subrosion, which is reason enough to likewise question the protective effect of this salt formation in the long run. (orig./HP) [de

  19. A LREE-depleted component in the Afar plume: Further evidence from Quaternary Djibouti basalts

    Science.gov (United States)

    Daoud, Mohamed A.; Maury, René C.; Barrat, Jean-Alix; Taylor, Rex N.; Le Gall, Bernard; Guillou, Hervé; Cotten, Joseph; Rolet, Joël

    2010-02-01

    Major, trace element and isotopic (Sr, Nd, Pb) data and unspiked K-Ar ages are presented for Quaternary (0.90-0.95 Ma old) basalts from the Hayyabley volcano, Djibouti. These basalts are LREE-depleted (La n/Sm n = 0.76-0.83), with 87Sr/ 86Sr ratios ranging from 0.70369 to 0.70376, and rather homogeneous 143Nd/ 144Nd ( ɛNd = + 5.9-+ 7.3) and Pb isotopic compositions ( 206Pb/ 204Pb = 18.47-18.55, 207Pb/ 204Pb = 15.52-15.57, 208Pb/ 204Pb = 38.62-38.77). They are very different from the underlying enriched Tadjoura Gulf basalts, and from the N-MORB erupted from the nascent oceanic ridges of the Red Sea and Gulf of Aden. Their compositions closely resemble those of (1) depleted Quaternary Manda Hararo basalts from the Afar depression in Ethiopia and (2) one Oligocene basalt from the Ethiopian Plateau trap series. Their trace element and Sr, Nd, Pb isotope systematics suggest the involvement of a discrete but minor LREE-depleted component, which is probably an intrinsic part of the Afar plume.

  20. Newly synthesized benzanthrone derivatives as prospective fluorescent membrane probes

    International Nuclear Information System (INIS)

    Zhytniakivska, Olga; Trusova, Valeriya; Gorbenko, Galyna; Kirilova, Elena; Kalnina, Inta; Kirilov, Georgiy; Kinnunen, Paavo

    2014-01-01

    Fluorescence spectral properties of a series of novel benzanthrone derivatives have been explored in lipid bilayers composed of zwitterionic lipid phosphatidylcholine (PC) and its mixtures with cholesterol (Chol) and anionic phospholipid cardiolipin (CL). Analysis of partition coefficients showed that all the examined compounds possess rather high lipid-associating ability, with the amidino derivatives exhibiting stronger membrane partitioning compared with the aminobenzanthrones. To understand how benzanthrone partition properties correlate with their structure, quantitative structure property relationship (QSPR) analysis was performed involving a range of quantum chemical molecular descriptors. -- Highlights: • Benzanthrone partitioning into lipid bilayer correlates with lipophilicity of the dyes. • Partition properties of benzanthrones depend on the dye dipole moment. • Amidino derivatives exhibit higher membrane affinity than aminobenzanthrones

  1. Quaternary Prevention, an Answer of Family Doctors to Overmedicalization

    Directory of Open Access Journals (Sweden)

    Marc Jamoulle

    2015-02-01

    Full Text Available In response to the questioning of Health Policy and Management (HPAM by colleagues on the role of rank and file family physicians in the same journal, the author, a family physician in Belgium, is trying to highlight the complexity and depth of the work of his colleagues and their contribution to the understanding of the organization and economy of healthcare. It addresses, in particular, the management of health elements throughout the ongoing relationship of the family doctor with his/her patients. It shows how the three dimensions of prevention, clearly included in the daily work, are complemented with the fourth dimension, quaternary prevention or prevention of medicine itself, whose understanding could help to control the economic and human costs of healthcare.

  2. Synthesis, crystal structure and electrical properties of the tetrahedral quaternary chalcogenides CuM{sub 2}InTe{sub 4} (M=Zn, Cd)

    Energy Technology Data Exchange (ETDEWEB)

    Nolas, George S., E-mail: gnolas@usf.edu [Department of Physics, University of South Florida, Tampa, FL 33620 (United States); Hassan, M. Shafiq; Dong, Yongkwan [Department of Physics, University of South Florida, Tampa, FL 33620 (United States); Martin, Joshua [Material Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899 (United States)

    2016-10-15

    Quaternary chalcogenides form a large class of materials that continue to be of interest for energy-related applications. Certain compositions have recently been identified as possessing good thermoelectric properties however these materials typically have the kesterite structure type with limited variation in composition. In this study we report on the structural, optical and electrical properties of the quaternary chalcogenides CuZn{sub 2}InTe{sub 4} and CuCd{sub 2}InTe{sub 4} which crystallize in the modified zinc-blende crystal structure, and compare their properties with that of CuZn{sub 2}InSe{sub 4}. These p-type semiconductors have direct band gaps of about 1 eV resulting in relatively high Seebeck coefficient and resistivity values. This work expands on the research into quaternary chalcogenides with new compositions and structure types in order to further the fundamental investigation of multinary chalcogenides for potential thermoelectrics applications. - Graphical abstract: The structural, optical and electrical properties of the quaternary chalcogenides CuZn{sub 2}InTe{sub 4} and CuCd{sub 2}InTe{sub 4} are reported for the first time. The unique crystal structure allows for relatively good electrical transports and therefore potential for thermoelectric applications. - Highlights: • The physical properties of CuZn{sub 2}InTe{sub 4} and CuCd{sub 2}InTe{sub 4} are reported for the first time. • These materials have potential for thermoelectric applications. • Their direct band gaps also suggest potential for photovoltaics applications.

  3. CAMAC programmable-control frequency synthesizer

    International Nuclear Information System (INIS)

    Yumaguzin, T.Kh.; Vyazovkin, D.E.; Nazirov, Eh.P.; Tuktarov, R.F.

    1989-01-01

    Synthesizer allows to set frequency with 0.015% accuracy and to scan it with variable step. Frequency controlled divider with further summing-up of divided frequency with fundamental one is used in synthesizer, and it has allowed to use digit of the input code and to obtain 3-4 MHz frequency range. Variation of operation flowsheet in the other frequency range is possible. K-155 and K-531 series microcircuits were used during development

  4. Polymerization-Driven Immobilization of dc-APGD Synthesized Gold Nanoparticles into a Quaternary Ammonium-Based Hydrogel Resulting in a Polymeric Nanocomposite with Heat-Transfer Applications

    Directory of Open Access Journals (Sweden)

    Piotr Cyganowski

    2018-03-01

    Full Text Available A new method for the production of nanocomposites, composed of gold nanoparticles (AuNPs and (vinylbenzyltrimethylammonium chloride-co-N,N-methylene bisacrylamide (VBTAC-co-MBA hydrogel, is described. Raw-AuNPs of defined optical and granulometric properties were synthesized using direct current atmospheric pressure glow discharge (dc-APGD generated in contact with a solution of HAuCl4. Different approaches to the polymerization-driven synthesis of Au/VBTAC-co-MBA nanocomposites were tested. It was established that homogenous dispersion of AuNPs in this new nanomaterial with was achieved in the presence of NaOH in the reaction mixture. The new nanocomposite was found to have excellent heat-transfer properties.

  5. Thermoluminescence and new 14C age estimates for late quaternary loesses in southwestern Nebraska

    Science.gov (United States)

    Maat, P.B.; Johnson, W.C.

    1996-01-01

    Loess of late Quaternary age mantles most of Nebraska south of the Platte River Valley. At least five late Quaternary loesses are recognized: from oldest to youngest, one or more undifferentiated pre-lllinoian loesses, the Loveland Loess, the Gilman Canyon Loess, which exhibits a well developed soil and rests unconformably on the Sangamon soil, the Peoria Loess capped by the Brady soil, and the Bignell Loess, which is distributed discontinuously. Previous research shows that the Loveland Loess is Illinoian. the Gilman Canyon Loess and Peoria Loess are Wisconsin, and the Bignell Loess is Holocene. We present here the first thermoluminescence (TL) age estimates and new C ages for these late Quaternary loesses at two key sections in southwestern Nebraska, the Eustis ash pit and the Bignell Hill road cut. TL age estimates from all samples collected from Eustis ash pit and Bignell Hill were internally consistent. TL and C age estimates from these two sections generally agree and support previous age determinations. The TL age estimate on Loveland Loess indicates deposition at 163 ka. TL and radiocarbon age estimates indicate that Oilman Canyon Loess, believed to be deposited during the Farmdale interstade, first began to accumulate at about 40 ka: the lower part of the Gilman Canyon Loess is 36 ka at Eustis and the middle of the unit is 30 ka at Bignell Hill. The lower and upper parts of the Peoria Loess give age estimates of 24 ka and 17 ka, respectively. TL age estimates for deposition of the Bignell Loess are 9 ka near the base, in agreement with radiocarbon age estimates, and 6 ka immediately below the modern soil, substantiating its Holocene age. Comparisons of TL age estimates with ??18O and insolation curves which show loess deposition during interglacial and interstadial as well as glacial periods, indicate that loess deposition on the Great Plains can occur under a variety of climatic conditions.

  6. Diploid hybrid origin of Ostryopsis intermedia (Betulaceae) in the Qinghai-Tibet Plateau triggered by Quaternary climate change.

    Science.gov (United States)

    Liu, Bingbing; Abbott, Richard J; Lu, Zhiqiang; Tian, Bin; Liu, Jianquan

    2014-06-01

    Despite the well-known effects that Quaternary climate oscillations had on shaping intraspecific diversity, their role in driving homoploid hybrid speciation is less clear. Here, we examine their importance in the putative homoploid hybrid origin and evolution of Ostryopsis intermedia, a diploid species occurring in the Qinghai-Tibet Plateau (QTP), a biodiversity hotspot. We investigated interspecific relationships between this species and its only other congeners, O. davidiana and O. nobilis, based on four sets of nuclear and chloroplast population genetic data and tested alternative speciation hypotheses. All nuclear data distinguished the three species clearly and supported a close relationship between O. intermedia and the disjunctly distributed O. davidiana. Chloroplast DNA sequence variation identified two tentative lineages, which distinguished O. intermedia from O. davidiana; however, both were present in O. nobilis. Admixture analyses of genetic polymorphisms at 20 SSR loci and sequence variation at 11 nuclear loci and approximate Bayesian computation (ABC) tests supported the hypothesis that O. intermedia originated by homoploid hybrid speciation from O. davidiana and O. nobilis. We further estimated that O. davidiana and O. nobilis diverged 6-11 Ma, while O. intermedia originated 0.5-1.2 Ma when O. davidiana is believed to have migrated southward, contacted and hybridized with O. nobilis possibly during the largest Quaternary glaciation that occurred in this region. Our findings highlight the importance of Quaternary climate change in the QTP in causing hybrid speciation in this important biodiversity hotspot. © 2014 John Wiley & Sons Ltd.

  7. Problems faced by newly diagnosed diabetes mellitus patients at ...

    African Journals Online (AJOL)

    Diabetes mellitus can be a frightening experience for newly diagnosed patients. The aim of this study was to determine and describe the problems faced by newly diagnosed diabetes mellitus patients at primary healthcare facilities at Mopani district, Limpopo Province. A qualitative, descriptive and contextual research ...

  8. Quaternary volcanism, tectonics, and sedimentation in the Idaho National Engineering Laboratory area

    Energy Technology Data Exchange (ETDEWEB)

    Hackett, W.R.; Smith, R.P.

    1992-09-01

    In this article, we discuss the regional context and describe localities for a two-day field excursion in the vicinity of the Idaho National Engineering Laboratory (INEL). We address several geologic themes: (1) Late Cenozoic, bimodal volcanism of the Eastern Snake River Plain (ESRP), (2) the regional tectonics and structural geology of the Basin and Range province to the northwest of the ESRP, (3) fluvial, lacustrine, and aeolian sedimentation in the INEL area, and (4) the influence of Quaternary volcanism and tectonics on sedimentation near the INEL.

  9. Quaternary volcanism, tectonics, and sedimentation in the Idaho National Engineering Laboratory area

    Energy Technology Data Exchange (ETDEWEB)

    Hackett, W.R.; Smith, R.P.

    1992-01-01

    In this article, we discuss the regional context and describe localities for a two-day field excursion in the vicinity of the Idaho National Engineering Laboratory (INEL). We address several geologic themes: (1) Late Cenozoic, bimodal volcanism of the Eastern Snake River Plain (ESRP), (2) the regional tectonics and structural geology of the Basin and Range province to the northwest of the ESRP, (3) fluvial, lacustrine, and aeolian sedimentation in the INEL area, and (4) the influence of Quaternary volcanism and tectonics on sedimentation near the INEL.

  10. Newly graduated nurses' use of knowledge sources in clinical decision-making

    DEFF Research Database (Denmark)

    Voldbjerg, Siri Lygum; Grønkjaer, Mette; Wiechula, Rick

    2017-01-01

    AIMS AND OBJECTIVES: To explore which knowledge sources newly graduated nurses' use in clinical decision-making and why and how they are used. BACKGROUND: In spite of an increased educational focus on skills and competencies within evidence based practice newly graduated nurses' ability to use...... approaches to strengthen the knowledgebase used in clinical decision-making. DESIGN AND METHODS: Ethnographic study using participant-observation and individual semi-structured interviews of nine Danish newly graduated nurses in medical and surgical hospital settings. RESULTS: Newly graduates use...... in clinical decision-making. If newly graduates are to be supported in an articulate and reflective use of a variety of sources, they have to be allocated to experienced nurses who model a reflective, articulate and balanced use of knowledge sources. This article is protected by copyright. All rights reserved....

  11. Quaternary (liquid + liquid) equilibrium data for the extraction of toluene from alkanes using the ionic liquid [EMim][MSO4

    International Nuclear Information System (INIS)

    Corderí, Sandra; Calvar, Noelia; Gómez, Elena; Domínguez, Ángeles

    2014-01-01

    Highlights: • EMim[MSO 4 ] was proposed as solvent for the extraction of toluene from alkanes. • The quaternary system {heptane + cyclohexane + toluene + [EMim][MSO 4 ]} was evaluated. • The extraction of toluene would be facilitated in the presence of one alkane. • Experimental LLE data were successfully correlated with the NRTL model. - Abstract: (Liquid + liquid) equilibrium (LLE) studies for the extraction of aromatics from alkanes present in the petroleum fractions are important to develop theoretical/semiempirical (liquid + liquid) equilibrium models, which are used in the design of extraction processes. In this work, the ionic liquid 1-ethyl-3-methylimidazolium methylsulfate, [EMim][MSO 4 ], was evaluated as potential solvent for the separation of toluene from heptane and cyclohexane. The LLE data for the quaternary system {heptane (1) + cyclohexane (2) + toluene (3) + [EMim][MSO 4 ] (4)} were experimentally determined at T = 298.15 K and atmospheric pressure. Moreover, the LLE data for the ternary systems {heptane or cyclohexane (1) + toluene (2) + [EMim][MSO 4 ] (3)} were also determined. Solute distribution ratios and selectivities were calculated and analysed in order to evaluate the capability of the ionic liquid to accomplish the separation target. A comparison between the solute distribution ratios and selectivities for the quaternary and the ternary systems was also made. Finally, the experimental tie-line data were correlated with the NRTL model

  12. Value of a newly sequenced bacterial genome

    DEFF Research Database (Denmark)

    Barbosa, Eudes; Aburjaile, Flavia F; Ramos, Rommel Tj

    2014-01-01

    and annotation will not be undertaken. It is important to know what is lost when we settle for a draft genome and to determine the "scientific value" of a newly sequenced genome. This review addresses the expected impact of newly sequenced genomes on antibacterial discovery and vaccinology. Also, it discusses...... heightened expectations that NGS would boost antibacterial discovery and vaccine development. Although many possible drug and vaccine targets have been discovered, the success rate of genome-based analysis has remained below expectations. Furthermore, NGS has had consequences for genome quality, resulting...

  13. On the high characteristic temperature of an InAs/GaAs/InGaAsP QD laser with an emission wavelength of ~1.5 μm on an InP substrate

    DEFF Research Database (Denmark)

    Zubov, F.; Semenova, Elizaveta; Kulkova, Irina

    2017-01-01

    We report on a study of lasers with an emission wavelength of about 1.5 μm and high temperature stability, synthesized on an InP (001) substrate. Self-organized InAs quantum dots capped with a thin GaAs layer are used as the active region of the laser. A quaternary InGaAsP solid solution with a b......We report on a study of lasers with an emission wavelength of about 1.5 μm and high temperature stability, synthesized on an InP (001) substrate. Self-organized InAs quantum dots capped with a thin GaAs layer are used as the active region of the laser. A quaternary InGaAsP solid solution...

  14. Corrosion inhibition of mild steel in acidic media using newly synthesized heterocyclic organic molecules: Correlation between inhibition efficiency and chemical structure

    Energy Technology Data Exchange (ETDEWEB)

    Ouici, H. B., E-mail: ouici.houari@yahoo.fr; Guendouzi, A., E-mail: guendouzzi@yahoo.fr [Departement of Chimistry, Faculty of Sciences, University of Saïda (Algeria); Benali, O. [Department of Biology, Faculty of Science, University of Saida (Algeria)

    2015-03-30

    The corrosion inhibition of mild steel in 5% HCl solutions by some new synthesized organic compounds namely 3-(2-methoxyphenyl) 5-mercapto-1. 2. 4-triazole (2-MMT), 3-(3-methoxyphenyl) 5-mercapto-1. 2. 4-triazole (3-MMT) and 3-(2-hydroxyphenyl) 5-mercapto-1. 2. 4-triazole (2-HMT) was investigated using weight loss and potentiostatic polarization techniques. These measurements reveal that the inhibition efficiency obtained by these compounds increased by increasing their concentration. The inhibition efficiency follows the order 2-MMT >3-MMT >2-HMT. Polarization studies show that these compounds are of the mixed type but dominantly act as a cathodic inhibitors for mild steel in 5% HCl solutions. These inhibitors function through adsorption following Langmuir isotherm. Activation energy and Gibbs free energy for adsorption of inhibitors are calculated. Molecular modeling has been conducted to correlate the corrosion inhibition properties with the calculated quantum chemical parameters.

  15. Quaternary geophysical framework of the northeastern North Carolina coastal system

    Science.gov (United States)

    Thieler, E.R.; Foster, D.S.; Mallinson, D.M.; Himmelstoss, E.A.; McNinch, J.E.; List, J.H.; Hammar-Klose, E.S.

    2013-01-01

    The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that mapped the Quaternary geologic framework of the estuaries, barrier islands, and inner continental shelf. This information provides a basis to understand the linkage between geologic framework, physical processes, and coastal evolution at time scales from storm events to millennia. The study area attracts significant tourism to its parks and beaches, contains a number of coastal communities, and supports a local fishing industry, all of which are impacted by coastal change. Knowledge derived from this research program can be used to mitigate hazards and facilitate effective management of this dynamic coastal system.

  16. Synthesizing Modular Invariants for Synchronous Code

    Directory of Open Access Journals (Sweden)

    Pierre-Loic Garoche

    2014-12-01

    Full Text Available In this paper, we explore different techniques to synthesize modular invariants for synchronous code encoded as Horn clauses. Modular invariants are a set of formulas that characterizes the validity of predicates. They are very useful for different aspects of analysis, synthesis, testing and program transformation. We describe two techniques to generate modular invariants for code written in the synchronous dataflow language Lustre. The first technique directly encodes the synchronous code in a modular fashion. While in the second technique, we synthesize modular invariants starting from a monolithic invariant. Both techniques, take advantage of analysis techniques based on property-directed reachability. We also describe a technique to minimize the synthesized invariants.

  17. Functionalizing aluminum substrata by quaternary ammonium for antifouling performances

    Science.gov (United States)

    He, Xiaoyan; Suo, Xinkun; Bai, Xiuqin; Yuan, Chengqing; Li, Hua

    2018-05-01

    Due to the great loss induced by biofouling, developing new strategies for combating biofouling has attracted extensive attention. Quaternary ammonium salts are potent cationic antimicrobials used in consumer products and their use for surface immobilization could create a contact-active antimicrobial layer. Here we report the facile preparation of a contact-active antifouling coating by tethering polyethyleneimine (PEI) onto flat/nanostructured aluminum surface by hydrogen bonding between PEI and AlOOH. Quaternized PEI (QPEI) is obtained through quaternization reactions. Biofouling testing suggests excellent antifouling performances of the samples by declining the adhesion of 95% Phaeodactylum tricornutum and 98% of Chlorella pyrenoidosa. The antifouling properties of PEI/QPEI are attributed predominately to their hydrophilic and antimicrobial nature. The technical route of PEI/QPEI surface grafting shows great potential for modifying marine infrastructures for enhanced antifouling performances.

  18. The pragmatic roots of American Quaternary geology and geomorphology

    Science.gov (United States)

    Baker, Victor R.

    1996-07-01

    H.L. Fairchild's words from the 1904 Geological Society of America Bulletin remain appropriate today: "Geologists have been too generous in allowing other people to make their philosophy for them". Geologists have quietly followed a methodological trinity involving (1) inspiration by analogy, (2) impartial and critical assessment of hypotheses, and (3) skepticism of authority (prevailing theoretical constraints or paradigms). These methods are described in classical papers by Quaternary geologists and geomorphologists, mostly written a century ago. In recent years these papers have all been criticized in modern philosophical terms with little appreciation for the late 19th century American philosophical tradition from which they arose. Recent scholarly research, however, has revealed some important aspects of that tradition, giving it a coherence that has largely been underappreciated as 20th century philosophy of science pursued its successive fads of logical positivism, critical rationalism, relativism, and deconstructivism — for all of which "science" is synonymous with "physics". Nearly all this ideology is geologically irrelevant. As philosophy of science in the late 20th century has come to be identical with philosophy of analytical physics, focused on explanations via ideal truths, much of geology has remained true to its classical doctrines of commonsensism, fallibilism, and realism. In contrast to the conceptualism and the reductionism of the analytical sciences, geology has emphasized synthetic thinking: the continuous activity of comparing, connecting, and putting together thoughts and perceptions. The classical methodological studies of geological reasoning all concern the formulation and testing of hypotheses. Analysis does not serve to provide the ultimate answers for intellectual puzzles predefined by limiting assumptions imposed on the real world. Rather, analysis in geology allows the investigator to consider the consequential effects of

  19. IODP Expeditions 303 and 306 Monitor Miocene- Quaternary Climate in the North Atlantic

    Directory of Open Access Journals (Sweden)

    Carlos Alvarez-Zarikian

    2006-03-01

    Full Text Available Introduction The IODP Expeditions 303 and 306 drilling sites were chosen for two reasons: (1 to capture Miocene-Quaternary millennial-scale climate variability in sensitive regions at the mouth of the Labrador Sea and in the North Atlantic icerafted debris (IRD belt (Ruddiman et al., 1977, and (2 to provide the sedimentary and paleomagnetic attributes, including adequate sedimentation rates, for constructinghigh-resolution isotopic and magnetic stratigraphies.High accumulation rates, reaching 20 cm ky-1, permit the study of millennial-scale variations in climate and in the Earth's magnetic fi eld over the past several million years, when the amplitude and frequency of climate variability changed substantially. Shipboard logging and scanning data (magnetic susceptibility and remanence, density, natural gamma radiation, digital images and color refl ectance and post-expedition x-ray fl uorescence (XRF scanning datahave revealed that the sediment cores recovered on Expeditions 303 and 306 contain detailed histories of millennial-scale climate and geomagnetic fi eld variability throughout the late Miocene to Quaternary epochs. The climate proxies will be integrated with paleomagnetic data to place the records of millennial-scale climate change into a high resolution stratigraphy based on oxygen isotope andrelative paleomagnetic intensity (RPI. The paleomagnetic record of polarity reversals, excursions and RPI in these cores is central to the construction of the stratigraphic template and will provide detailed documentation of geomagnetic fi eld behavior.

  20. Mapping process and age of Quaternary deposits on Santa Rosa Island, Channel Islands National Park, California

    Science.gov (United States)

    Schmidt, K. M.; Minor, S. A.; Bedford, D.

    2016-12-01

    Employing a geomorphic process-age classification scheme, we mapped the Quaternary surficial geology of Santa Rosa (SRI) within the Channel Islands National Park. This detailed (1:12,000 scale) map represents upland erosional transport processes and alluvial, fluvial, eolian, beach, marine terrace, mass wasting, and mixed depositional processes. Mapping was motivated through an agreement with the National Park Service and is intended to aid natural resource assessments, including post-grazing disturbance recovery and identification of mass wasting and tectonic hazards. We obtained numerous detailed geologic field observations, fossils for faunal identification as age control, and materials for numeric dating. This GPS-located field information provides ground truth for delineating map units and faults using GIS-based datasets- high-resolution (sub-meter) aerial imagery, LiDAR-based DEMs and derivative raster products. Mapped geologic units denote surface processes and Quaternary faults constrain deformation kinematics and rates, which inform models of landscape change. Significant findings include: 1) Flights of older Pleistocene (>120 ka) and possibly Pliocene marine terraces were identified beneath younger alluvial and eolian deposits at elevations as much as 275 m above modern sea level. Such elevated terraces suggest that SRI was a smaller, more submerged island in the late Neogene and (or) early Pleistocene prior to tectonic uplift. 2) Structural and geomorphic observations made along the potentially seismogenic SRI fault indicate a protracted slip history during the late Neogene and Quaternary involving early normal slip, later strike slip, and recent reverse slip. These changes in slip mode explain a marked contrast in island physiography across the fault. 3) Many of the steeper slopes are dramatically stripped of regolith, with exposed bedrock and deeply incised gullies, presumably due effects related to past grazing practices. 4) Surface water presence is

  1. The ``Problem of the quaternary'' and the taxonomic rank of the late cenozoic in the international stratigraphic scale

    Science.gov (United States)

    Zubakov, V. A.

    2011-02-01

    An international scientific conflict has arisen around the International Stratigraphic Scale, the main document that regulates the rules of reading of geological records and, hence, concerns all Earth sciences. The matter of debate is the geological time scale of 2004, developed by the International Commission on Stratigraphy, where the Quaternary system was abandoned. This ICS decision triggered a protest among Quaternary geologists, members of INQUA, and became the subject of much controversy. This article provides a comprehensive analysis of the Quaternary problem and proposes a reasonable scientific solution that may be appropriate for both parties. The subject of Late Cenozoic geology is discussed: glaciations, human evolution, and recent deposits. In contrast to Charles Lyell's definition of the Plio-Pleistocene according to the percentage of modern mollusk species, it is defined here as a blanket formation, which is correlative to the topography and consists of mapped stratogens hosting fossils of modern biogeocenoses. Features of the description of the Plio-Pleistocene in terms of gravitational orbital tuning are considered. Four paleogeographic phases of modern environment evolution are recognized and ranked as stages: (1) The Messinian evolutionary explosion involved the appearance of many biogeocenoses and the bipedal walking of our extinct ancestors armed with sticks. It was a consequence of the Early Greenland (7.6 Ma BP) and Patagonian (6.7 Ma BP) hyperglaciations. (2) The Zanclean age is marked by climatic and hydrological but not evolutionary boundaries. (3) The appearance of the Villafranchian animal assemblage and Australopithecus, who used stones as weapon: 4.0-3.6 Ma BP. Orogeny and isolation of the Arctic Ocean changed the global climate dramatically. (4) The sexual revolution became the third evolutionary jump: the appearance of the first woman, "Eve", and the genus Homo with her: 1.9 Ma BP. According to the current view, the Plio

  2. Newly Generated Liquid Waste Processing Alternatives Study, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Landman, William Henry; Bates, Steven Odum; Bonnema, Bruce Edward; Palmer, Stanley Leland; Podgorney, Anna Kristine; Walsh, Stephanie

    2002-09-01

    This report identifies and evaluates three options for treating newly generated liquid waste at the Idaho Nuclear Technology and Engineering Center of the Idaho National Engineering and Environmental Laboratory. The three options are: (a) treat the waste using processing facilities designed for treating sodium-bearing waste, (b) treat the waste using subcontractor-supplied mobile systems, or (c) treat the waste using a special facility designed and constructed for that purpose. In studying these options, engineers concluded that the best approach is to store the newly generated liquid waste until a sodium-bearing waste treatment facility is available and then to co-process the stored inventory of the newly generated waste with the sodium-bearing waste. After the sodium-bearing waste facility completes its mission, two paths are available. The newly generated liquid waste could be treated using the subcontractor-supplied system or the sodium-bearing waste facility or a portion of it. The final decision depends on the design of the sodium-bearing waste treatment facility, which will be completed in coming years.

  3. Investigation of mineral composition of differently treated devonian, quaternary and triassic clays of Latvia

    International Nuclear Information System (INIS)

    Kosorukovs, A.; Viss, R.

    1999-01-01

    Clayey fractions (particle size less than 5 μm )of the Latvian Devonian (Kuprava and Liepa deposits), Quaternary (Laza and Ugale deposits) and Triassic (Akmene deposit, Republic of Lithuania) clays have been obtained. The clayey fractions were converted in the form in which all the cations were exchanged for magnesium ions. After the ion exchange the fractions were treated with dimethyl sulfoxide or glycerol in the course for two days, one sample being subjected to thermal treatment at 550±110 C for two hours. Diffractograms for the treated samples have been obtained using a DRON-2,0 diffractometer (Co-radiation). Analysis of the obtained diffractograms show that: 1) the main clayey minerals of the Devonian clays occur to be hydromicas (mainly hydromuscovite) containing admixtures of kaolinite and quartz; 2) the main clayey minerals of the Quarternary clays also occur to be hydromicas - mixtures of hydrobiotite and hydromuscovite containing admixtures of kaolinite and iron-containing chlorite; 3) smectite occurs to be the main mineral of the Triassic clay; it contains admixtures of hydromica and chlorite; 4) the Triassic and Quaternary clays contain fine- and coarse-grained carbonates, mainly calcite, in quantities of 10-16%; 5) iron and titanium are included in fine grained minerals. (author)

  4. New quaternary indides RE{sub 7}Ni{sub 5-x}Ge{sub 3+x}In{sub 6} (RE = La, Nd, Sm)

    Energy Technology Data Exchange (ETDEWEB)

    Dominyuk, Nataliya [Lviv Univ. (Ukraine). Dept. of Inorganic Chemistry; Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Zaremba, Vasyl I. [Lviv Univ. (Ukraine). Dept. of Inorganic Chemistry; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie

    2011-04-15

    The quaternary indides RE{sub 7}Ni{sub 5-x}Ge{sub 3+x}In{sub 6} (RE = La,Nd, Sm) were synthesized from the elements by arc-melting. Single crystals were grown by slow cooling of the polycrystalline samples. The structures were characterized by powder and single-crystal X-ray diffraction: Ce{sub 7}Ni{sub 4.73}Ge{sub 3.27}In{sub 6} type, P6/m, Z = 1, a = 1147.05(9), c = 426.82(4) pm, wR2 = 0.0652, 528 F{sup 2} values for La{sub 7}Ni{sub 4.46}Ge{sub 3.54}In{sub 6}, a = 1134.5(7), c = 407.1(7) pm, wR2 = 0.0419, 441 F{sup 2} values for Nd{sub 7}Ni{sub 4.91}Ge{sub 3.09}In{sub 6}, and a = 1133.5(2), c = 404.3(1) pm, wR2 = 0.0619, 498 F{sup 2} values for Sm{sub 7}Ni{sub 4.31}Ge{sub 3.69}In{sub 6}, with 25 parameters per refinement. Characteristic features of the RE{sub 7}Ni{sub 5-x}Ge{sub 3+x}In{sub 6} structures are hexagonal, AlB{sub 2}-related prisms around the RE1 atoms and a tricapped, trigonalprismatic coordination of the nickel atoms. (orig.)

  5. Late Quaternary seismic sequence stratigraphy of the Gulf of Kachchh, northwest of India

    Digital Repository Service at National Institute of Oceanography (India)

    Michael, L.; Rao, D.G.; Krishna, K.S.; Vora, K.H.

    sediments of Late Quaternary (Chamyal, Maurya, and Raj, 2003) and Holocene (Juyal et al., 1995; Prakash et al., 2000) of Saurashtra and Kachchh peninsula and the submergence of coastal areas i.e., Bet Dwarka sometime after 3,870 yr BP (Gaur, Vora... (Juyal et al., 1995; Prakash et al., 2000) and Recent (Chandrasekhar et al., 2004) mark post-Pleistocene-Holocene neotectonics of the Saurashtra and Kachchh peninsula. Contrary to that, submergence of coastal areas i.e., Bet Dwarka sometime after 3...

  6. Agricultural contaminants in Quaternary aquitards: A review of occurrence and fate in North America

    Science.gov (United States)

    Rodvang, S. J.; Simpkins, W. W.

    2001-01-01

    The intensity of agriculture has increased significantly during the past 30 years, resulting in increased detection of agricultural contaminants (nutrients, pesticides, salts, trace elements, and pathogens) in groundwater. Till, glaciolacustrine, and loess deposits of Quaternary age compose the most common surficial deposits underlying agricultural areas in North America. Quaternary aquitards generally contain higher concentrations of solid organic carbon (SOC, as much as 1.4%), dissolved organic carbon (DOC, as much as 205 mg/L), and reduced sulfur (as much as 0.9%) than do aquifers. Their potential to sorb pesticides increases with the percent of older SOC, because diagenesis increases Koc. Denitrification consistently reduces nitrate to non-detectable levels in unweathered Quaternary aquitards. Organic carbon of Quaternary age is a more labile electron donor than carbon from shale clasts. Pyrite is a more labile electron donor than carbon in many instances. Unweathered Quaternary aquitards provide a high degree of protection for underlying aquifers, due to their large reserves of SOC and reduced sulfur for sorption and denitrification, combined with their typically low hydraulic conductivity. In contrast, agricultural contaminants are common in weathered Quaternary aquitards. Lower reserves of reduced sulfur and sorptive/labile organic carbon, and a higher bulk K due to fractures, limit their ability to attenuate nitrate and pesticides. Subsurface drainage, which is common in Quaternary aquitards because of high water tables, bypasses the attenuation capacity of Quaternary aquitards and facilitates the transport of agricultural contaminants to surface water. Résumé. L'agriculture s'est significativement accrue au cours des dernières 30 années, provoquant une détection plus fréquente dans les eaux souterraines de contaminants agricoles (engrais, pesticides, sels, éléments en traces et germes pathogènes). Les moraines, les formations glacio-lacustres et

  7. Phytolith analysis in fluvial quaternary sediment (San Salvador and Palmar formation) Uruguay river and Argentina eastern

    International Nuclear Information System (INIS)

    Patterer, N.; Passeggi, E.; Zucol, A.; Brea, M.; Krohling, D.

    2012-01-01

    This work is about two microfossils fluvial units deposited by the Uruguay river during the Quaternary. These are San Salvador and Palmar formation (Plio-Pleistocene - Upper Pleistocene).The Palmar formation is a band of 4-15 km along the right bank of the Uruguay river outcropping from the eastern provinces of Corrientes and Entre Rios, to Concepcion del Uruguay

  8. Quantifying Quaternary Deformation in the Eastern Cordillera of the Colombian Andes Using Cosmogenic Nuclide Geochronology and Fluvial Geomorphology

    Science.gov (United States)

    Dalman, E.; Taylor, M. H.; Veloza-fajardo, G.; Mora, A.

    2014-12-01

    Northwest South America is actively deforming through the interaction between the Nazca, South American, and Caribbean plates. Though the Colombian Andes are well studied, much uncertainty remains in the rate of Quaternary deformation along the east directed frontal thrust faults hundreds of kilometers in board from the subduction zones. The eastern foothills of the Eastern Cordillera (EC) preserve deformed landforms, allowing us to quantify incision rates. Using 10Be in-situ terrestrial cosmogenic nuclide (TCN) geochronology, we dated 2 deformed fluvial terraces in the hanging wall of the Guaicaramo thrust fault. From the 10Be concentration and terrace profile relative to local base level, we calculated incision rates. We present a reconstructed slip history of the Guaicaramo thrust fault and its Quaternary slip rate. Furthermore, to quantify the regional Quaternary deformation, we look at the fluvial response to tectonic uplift. Approximately 20 streams along the eastern foothills of the Eastern Cordillera (EC) were studied using a digital elevation model (DEM). From the DEM, longitudinal profiles were created and normalized channel steepness (Ksn) values calculated from plots of drainage area vs. slope. Knickpoints in the longitudinal profiles can record transient perturbations or differential uplift. Calculated Ksn values indicate that the EC is experiencing high rates of uplift, with the highest mean Ksn values occurring in the Cocuy region. Mean channel steepness values along strike of the foothills are related to increasing uplift rates from south to north. In contrast, we suggest that high channel steepness values in the south appear to be controlled by high rates of annual precipitation.

  9. Quaternary faulting in the Tatra Mountains, evidence from cave morphology and fault-slip analysis

    OpenAIRE

    Szczygieł Jacek

    2015-01-01

    Tectonically deformed cave passages in the Tatra Mts (Central Western Carpathians) indicate some fault activity during the Quaternary. Displacements occur in the youngest passages of the caves indicating (based on previous U-series dating of speleothems) an Eemian or younger age for those faults, and so one tectonic stage. On the basis of stress analysis and geomorphological observations, two different mechanisms are proposed as responsible for the development of these displacements. The firs...

  10. Ring-Contraction Strategy for the Practical, Scalable, Catalytic Asymmetric Synthesis of Versatile γ-Quaternary Acylcyclopentenes

    KAUST Repository

    Hong, Allen Y.

    2011-02-24

    Contraction action! A simple protocol for the catalytic asymmetric synthesis of highly functionalized γ-quaternary acylcyclopentenes (see schematic) in up to 91 % overall yield and 92 % ee has been developed. The reaction sequence employs a palladium-catalyzed enantioselective alkylation reaction and exploits the unusual stability of β-hydroxy cycloheptanones to achieve a general and robust method for performing two-carbon ring contractions.

  11. Ring-Contraction Strategy for the Practical, Scalable, Catalytic Asymmetric Synthesis of Versatile γ-Quaternary Acylcyclopentenes

    KAUST Repository

    Hong, Allen Y.; Krout, Michael R.; Jensen, Thomas; Bennett, Nathan B.; Harned, Andrew M.; Stoltz, Brian M.

    2011-01-01

    Contraction action! A simple protocol for the catalytic asymmetric synthesis of highly functionalized γ-quaternary acylcyclopentenes (see schematic) in up to 91 % overall yield and 92 % ee has been developed. The reaction sequence employs a palladium-catalyzed enantioselective alkylation reaction and exploits the unusual stability of β-hydroxy cycloheptanones to achieve a general and robust method for performing two-carbon ring contractions.

  12. Observation of the bone mineral density of newly formed bone using rabbits. Compared with newly formed bone around implants and cortical bone

    International Nuclear Information System (INIS)

    Nakada, Hiroshi; Numata, Yasuko; Sakae, Toshiro; Tamaki, Hiroyuki; Kato, Takao

    2009-01-01

    There have been many studies reporting that newly formed bone around implants is spongy bone. However, although the morphology is reported as being like spongy bone, it is difficult to discriminate whether the bone quality of newly formed bone appears similar to osteoid or cortical bone; therefore, evaluation of bone quality is required. The aims of this study were to measure the bone mineral density (BMD) values of newly formed bone around implants after 4, 8, 16, 24 and 48 weeks, to represent these values on three-dimensional color mapping (3Dmap), and to evaluate the change in bone quality associated with newly formed bone around implants. The animal experimental protocol of this study was approved by the Ethics Committee for Animal Experiments of our University. This experiment used 20 surface treatment implants (Ti-6Al-4V alloy: 3.1 mm in diameter and 30.0 mm in length) by grit-blasting. They were embedded into surgically created flaws in femurs of 20 New Zealand white rabbits (16 weeks old, male). The rabbits were sacrificed with an ear intravenous overdose of pentobarbital sodium under general anesthesia each period, and the femurs were resected. We measured BMD of newly formed bone around implants and cortical bone using Micro-CT, and the BMD distribution map of 3Dmap (TRI/3D Bon BMD, Ratoc System Engineering). The BMD of cortical bone was 1,026.3±44.3 mg/cm 3 at 4 weeks, 1,023.8±40.9 mg/cm 3 at 8 weeks, 1,048.2±45.6 mg/cm 3 at 16 weeks, 1,067.2±60.2 mg/cm 3 at 24 weeks, and 1,069.3±50.7 mg/cm 3 at 48 weeks after implantation, showing a non-significant increase each period. The BMD of newly formed bone around implants was 296.8±25.6 mg/cm 3 at 4 weeks, 525.0±72.4 mg/cm 3 at 8 weeks, 691.2±26.0 mg/cm 3 at 16 weeks, 776.9±27.7 mg/cm 3 at 24 weeks, and 845.2±23.1 mg/cm 3 at 48 weeks after implantation, showing a significant increase after each period. It was revealed that the color scale of newly formed bone was Low level at 4 weeks, and then it

  13. Quaternary reciprocal system Na,K//Cl,Co3,MoO4

    International Nuclear Information System (INIS)

    Kochkarov, Zh.A.; Gasanaliev, A.M.

    2004-01-01

    Quaternary reciprocal system Na,K//Cl,Co 3 ,MoO 4 has been investigated for the first time by differential thermal analysis using the methods of projective and differential geometry. A stable (KCl) 2 -Na 2 CO 3 -K 2 CO 3 -K 2 MoO 4 tetrahedron and (NaCl) 2 -(KCl) 2 -Na 2 CO 3 -K 2 MoO 4 -Na 2 MoO 4 pentatope have been revealed in the system. It has been found that four quadruple invariant points are realized in the Na,K//Cl,Co 3 ,MoO 4 system, including one eutectic and three peritectic points [ru

  14. Experimental and theoretical studies on tautomeric structures of a newly synthesized 2,2‧(hydrazine-1,2-diylidenebis(propan-1-yl-1-ylidene))diphenol

    Science.gov (United States)

    Karakurt, Tuncay; Cukurovali, Alaaddin; Subasi, Nuriye Tuna; Onaran, Abdurrahman; Ece, Abdulilah; Eker, Sıtkı; Kani, Ibrahim

    2018-02-01

    In the present study, a single crystal of a Schiff base, 2,2‧(hydrazine-1,2-diylidenebis(propan-1-yl-1-ylidene))diphenol, was synthesized. The structure of the synthesized crystal was confirmed by 1H and 13C NMR spectroscopic and X-ray diffraction analysis techniques. Experimental and theoretical studies were carried out on two tautomeric structures. It has been observed that the title compound studied can be in two different tautomeric forms, phenol-imine and keto-amine. Theoretical calculations have been performed to support experimental results. Accordingly, the geometric parameters of the compound were optimized by the density functional theory (DFT) method using the Gaussian 09 and Quantum Espresso (QE) packet program was used for periodic boundary conditions (PBC) studies. Furthermore, the compound was also tested for in vitro antifungal activity against Sclerotinia sclerotiorum, Alternaria solani, Fusarium oxysporum f. sp. lycopersici and Monilinia fructigena plant pathogens. Promising inhibition profiles were observed especially towards A. solani. Finally, molecular docking studies and post-docking procedure based on Molecular Mechanics-Generalized Born Surface Area (MM-GBSA) were also carried out to get insight into the compound's binding interactions with the potential. Although theoretical calculations showed that the phenol-imine form was more stable, keto-amine form was predicted to have better binding affinity which was concluded to result from loss of rotational entropy in phenol-imine upon binding. The results obtained here from both experimental and computational methods might serve as a potential lead in the development of novel anti-fungal agents.

  15. Non-linear response of the Golo River system, Corsica, France, to Late Quaternary climatic and sea level variations

    NARCIS (Netherlands)

    Forzoni, A.; Storms, J.E.A.; Reimann, T.; Moreau, J.; Jouet, G.

    2015-01-01

    Disentangling the impact of climatic and sea level variations on fluvio-deltaic stratigraphy is still an outstanding question in sedimentary geology and geomorphology. We used the Golo River system, Corsica, France, as a natural laboratory to investigate the impact of Late Quaternary climate and sea

  16. Thermodynamic modeling of ternary and quaternary (liquid + liquid) systems containing water, FeCl3, HCl and diisopropyl ether

    NARCIS (Netherlands)

    Milosevic, M.; Hendriks, I.; Smits, R.E.R.; Schuur, B.; Haan, de A.B.

    2013-01-01

    Liquid–liquid extraction using ethers as solvents is a potentially energy saving alternative for the concentration of aqueous ferric chloride solutions. Adequate thermodynamic models that describe the behavior of the resulting quaternary systems (FeCl3, ether, acid and water) are not available in

  17. Geological and climatic changes in quaternary shaped the evolutionary history of Calibrachoa heterophylla, an endemic South-Atlantic species of petunia.

    Science.gov (United States)

    Mäder, Geraldo; Fregonezi, Jéferson N; Lorenz-Lemke, Aline P; Bonatto, Sandro L; Freitas, Loreta B

    2013-08-29

    The glacial and interglacial cycles that characterized the Quaternary greatly affected the distribution and genetic diversity of plants. In the Neotropics, few phylogeographic studies have focused on coastal species outside of the Atlantic Rainforest. Climatic and sea level changes during the Quaternary played an important role in the evolutionary history of many organisms found in coastal regions. To contribute to a better understanding of plant evolution in this environment in Southern South America, we focused on Calibrachoa heterophylla (Solanaceae), an endemic and vulnerable wild petunia species from the South Atlantic Coastal Plain (SACP). We assessed DNA sequences from two cpDNA intergenic spacers and analyzed them using a phylogeographic approach. The present phylogeographic study reveals the influence of complex geologic and climatic events on patterns of genetic diversification. The results indicate that C. heterophylla originated inland and subsequently colonized the SACP; the data show that the inland haplogroup is more ancient than the coastal one and that the inland was not affected by sea level changes in the Quaternary. The major diversification of C. heterophylla that occurred after 0.4 Myr was linked to sea level oscillations in the Quaternary, and any diversification that occurred before this time was obscured by marine transgressions that occurred before the coastal sand barrier's formation. Results of the Bayesian skyline plot showed a recent population expansion detected in C. heterophylla seems to be related to an increase in temperature and humidity that occurred at the beginning of the Holocene. The geographic clades have been formed when the coastal plain was deeply dissected by paleochannels and these correlate very well with the distributional limits of the clades. The four major sea transgressions formed a series of four sand barriers parallel to the coast that progressively increased the availability of coastal areas after the

  18. The practical skills of newly qualified nurses.

    Science.gov (United States)

    Danbjørg, Dorthe Boe; Birkelund, Regner

    2011-02-01

    This paper reports the findings from a study of newly qualified nurses and which subjects the nurses regarded as the most important in order to be able to live up to the requirements of clinical practice, and how they experience their potential for developing practical and moral skills, after the decrease in practical training. A qualitative approach guided the research process and the analysis of the data. The data was collected by participant observation and qualitative interviews with four nurses as informants. The conclusions made in this study are based on the statements and the observations of the newly qualified nurses. Our findings are discussed in relation to the Aristotelian concept and other relevant literature. The main message is that the newly qualified nurses did not feel equipped when they finished their training. This could be interpreted as a direct consequence of the decrease in practical training. Our study also underlines that the way nursing theory is perceived and taught is problematic. The interviews revealed that the nurses think that nursing theories should be applied directly in practice. This misunderstanding is probably also applicable to the teachers of the theories. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Late Pliocene Quaternary tectonics in the frontal part of the SE Carpathians: Insights from tectonic geomorphology

    Science.gov (United States)

    Necea, Diana; Fielitz, W.; Matenco, L.

    2005-12-01

    The Romanian East Carpathians display large-scale heterogeneities along the mountain belt, unusual foredeep geometries, significant post-collisional and neotectonic activity, and major variations in topography, mostly developed in the aftermath of late Miocene (Sarmatian; ˜11 Ma) subduction/underthrusting and continental collision between the East European/Scythian/Moesian foreland and the inner Carpathians Tisza-Dacia unit. In particular, the SE corner of the arcuate orogenic belt represents the place of still active large-scale differential vertical movements between the uplifting mountain chain and the subsiding Focşani foredeep basin. In this key area, we have analysed the configuration of the present day landforms and the drainage patterns in order to quantify the amplitude, timing and kinematics of these post-collisional late Pliocene-Quaternary vertical movements. A river network is incising in the upstream a high topography consisting of the external Carpathians nappes and the Pliocene-Lower Pleistocene sediments of the foreland. Further eastwards in the downstream, this network is cross-cutting a low topography consisting of the Middle Pleistocene-Holocene sediments of the foreland. Geological observations and well-preserved geomorphic features demonstrate a complex succession of geological structures. The late Pliocene-Holocene tectonic evolution is generally characterised by coeval uplift in the mountain chain and subsidence in the foreland. At a more detailed scale, these vertical movements took place in pulses of accelerated motion, with laterally variable amplitude both in space and in time. After a first late Pliocene uplifting period, subsidence took place during the Earliest Pleistocene resulting in a basal Quaternary unconformity. This was followed by two, quantifiable periods of increased uplift, which affected the studied area at the transition between the Carpathians orogen and the Focşani foreland basin in the late Early Pleistocene and the

  20. Newly graduated nurses' use of knowledge sources: a meta-ethnography.

    Science.gov (United States)

    Voldbjerg, Siri Lygum; Grønkjaer, Mette; Sørensen, Erik Elgaard; Hall, Elisabeth O C

    2016-08-01

    To advance evidence on newly graduated nurses' use of knowledge sources. Clinical decisions need to be evidence-based and understanding the knowledge sources that newly graduated nurses use will inform both education and practice. Qualitative studies on newly graduated nurses' use of knowledge sources are increasing though generated from scattered healthcare contexts. Therefore, a metasynthesis of qualitative research on what knowledge sources new graduates use in decision-making was conducted. Meta-ethnography. Nineteen reports, representing 17 studies, published from 2000-2014 were identified from iterative searches in relevant databases from May 2013-May 2014. Included reports were appraised for quality and Noblit and Hare's meta-ethnography guided the interpretation and synthesis of data. Newly graduated nurses' use of knowledge sources during their first 2-year postgraduation were interpreted in the main theme 'self and others as knowledge sources,' with two subthemes 'doing and following' and 'knowing and doing,' each with several elucidating categories. The metasynthesis revealed a line of argument among the report findings underscoring progression in knowledge use and perception of competence and confidence among newly graduated nurses. The transition phase, feeling of confidence and ability to use critical thinking and reflection, has a great impact on knowledge sources incorporated in clinical decisions. The synthesis accentuates that for use of newly graduated nurses' qualifications and skills in evidence-based practice, clinical practice needs to provide a supportive environment which nurtures critical thinking and questions and articulates use of multiple knowledge sources. © 2016 John Wiley & Sons Ltd.

  1. Coupling of tertiary and quaternary changes in human hemoglobin: A 1D and 2D NMR study of hemoglobin Saint Mande (βN102Y)

    International Nuclear Information System (INIS)

    Craescu, C.T.; Blouquit, Y.; Mispelter, J.

    1990-01-01

    Hemoglobin Saint Mande (βN102Y) is a low-affinity mutant with the substitution site situated in the quaternary-sensitive α 1 β 2 interface. In adult hemoglobin the Asn102β contributes to the stability of the liganded (R) state, forming a hydrogen bond with Asp94α. The quaternary and tertiary perturbations subsequent to the Tyr for Asn substitution in monocarboxylated hemoglobin Saint Mande have been investigated by one-and two-dimensional nuclear magnetic resonance (NMR) spectroscopy. Analysis of the one-dinensional NMR spectra of the liganded and unliganded samples in 1 H 2 O provides evidence that both R and T quaternary structures of Hb Saint Mande are different from the corresponding ones in HbA. In the monocarboxylated form of the mutant hemoglobin, at acid pH, the authors have observed the disappearance of an R-type hydrogen bond and the appearance of a new one whose proton resonates like a deoxy T marker. Using two-dimensional NMR methods and on the basis of previous results on the monocarboxylated HbA, they have obtained a significant number of resonance assignments in the spectra of monocarboxylated Hb Saint Mande at pH 5.6 in the presence or absence of a strong allosteric effector, inositol hexaphosphate. This enabled us to characterize the tertiary conformational changes triggered by the quaternary-state modification. The observed structural variations are confined within the heme pocket regions but concern both the α and β subunits

  2. Maps of Quaternary Deposits and Liquefaction Susceptibility in the Central San Francisco Bay Region, California

    Science.gov (United States)

    Witter, Robert C.; Knudsen, Keith L.; Sowers, Janet M.; Wentworth, Carl M.; Koehler, Richard D.; Randolph, Carolyn E.; Brooks, Suzanna K.; Gans, Kathleen D.

    2006-01-01

    This report presents a map and database of Quaternary deposits and liquefaction susceptibility for the urban core of the San Francisco Bay region. It supercedes the equivalent area of U.S. Geological Survey Open-File Report 00-444 (Knudsen and others, 2000), which covers the larger 9-county San Francisco Bay region. The report consists of (1) a spatial database, (2) two small-scale colored maps (Quaternary deposits and liquefaction susceptibility), (3) a text describing the Quaternary map and liquefaction interpretation (part 3), and (4) a text introducing the report and describing the database (part 1). All parts of the report are digital; part 1 describes the database and digital files and how to obtain them by downloading across the internet. The nine counties surrounding San Francisco Bay straddle the San Andreas fault system, which exposes the region to serious earthquake hazard (Working Group on California Earthquake Probabilities, 1999). Much of the land adjacent to the Bay and the major rivers and streams is underlain by unconsolidated deposits that are particularly vulnerable to earthquake shaking and liquefaction of water-saturated granular sediment. This new map provides a consistent detailed treatment of the central part of the 9-county region in which much of the mapping of Open-File Report 00-444 was either at smaller (less detailed) scale or represented only preliminary revision of earlier work. Like Open-File Report 00-444, the current mapping uses geomorphic expression, pedogenic soils, inferred depositional environments, and geologic age to define and distinguish the map units. Further scrutiny of the factors controlling liquefaction susceptibility has led to some changes relative to Open-File Report 00-444: particularly the reclassification of San Francisco Bay mud (Qhbm) to have only MODERATE susceptibility and the rating of artificial fills according to the Quaternary map units inferred to underlie them (other than dams - adf). The two colored

  3. 40Ar/39Ar dating of Quaternary volcanic ashes by multi-collection noble gas mass spectrometry: protocols, precision and intercalibration

    DEFF Research Database (Denmark)

    Storey, Michael; Rivera, Tiffany; Flude, Stephanie

    ) higher mass resolution allows hydrocarbon interferences to be pseudo resolved for the different argon isotopes; and (iv) multi-collection, allowing more data to be gathered in a fixed time in comparison with single-collector peak-switching measurements. We evaluate (i) protocols for detector inter......The recent availability of commercial high-resolution, multi-collector, noble gas mass spectrometers equipped with ion-counting electron multipliers provides new opportunities for improved precision in 40Ar/39Ar dating. This is particularly true for single crystal dating of Quaternary aged samples...... where potassium-bearing phenocrysts may contain relatively small amounts of radiogenic 40Ar. In 2005, the Quaternary Dating Laboratory, Roskilde University, installed a Nu-Instruments multi-collector Noblesse noble gas mass spectrometer, which is configured with a Faraday detector and three ion...

  4. The geological characteristics during the quaternary period around Japan island

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, Shigeru [Chuo Kaihatsu Corp., Enterprises Promotion Bureau, Tokyo (Japan); Sakamoto, Yoshiaki; Ogawa, Hiromichi; Nakayama, Shinichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-11-01

    Radioactive wastes arising from radioisotope facilities and nuclear research facilities should be disposed of in the surface of the earth, the shallow underground, the adequate depth and the deep underground according to radioactivity concentrations, and should be managed during several hundreds years. The earth scientific phenomena observed in Japan island at present occurred continuously from the past, and the same phenomena at the future should occur in the similar factor. Therefore, for the purpose to get the fundamental data for the selection of disposal site, this report reviewed on the genesis and classification of the sediments, earth scientific phenomena observed in Japan island and the feature of each place (10 districts) concerning to the Quaternary period in the newest geological time unit. (author)

  5. Late Quaternary climatic changes in the Ross Sea area, Antarctica

    International Nuclear Information System (INIS)

    Brambati, A.; Melis, R.; Quaia, T.; Salvi, G.

    2002-01-01

    Ten cores from the Ross Sea continental margin were investigated to detect Late Quaternary climatic changes. Two main climatic cycles over the last 300,000 yr (isotope stages 1-8) were recognised in cores from the continental slope, whereas minor fluctuations over the last 30,000 yr were found in cores from the continental shelf. The occurrence of calcareous taxa within the Last Glacial interval and their subsequent disappearance reveal a general raising of the CCD during the last climatic cycle. In addition, periodical trends of c. 400, c. 700, and c. 1400 yr determined on calcareous foraminifers from sediments of the Joides Basin, indicate fluctuations of the Ross Ice Shelf between 15 and 30 ka BP. (author). 24 refs., 5 figs

  6. Assessment voice synthesizers for reading in digital books

    Directory of Open Access Journals (Sweden)

    Sérvulo Fernandes da Silva Neto

    2013-07-01

    Full Text Available The digital accessibility shows ways to information access in digital media that assist people with different types of disabilities to a better interaction with the computer independent of its limitations. Of these tools are composed by voice synthesizers, that supposedly simplifying their access to any recorded knowledge through digital technologies. However such tools have emerged originally in countries foreign language. Which brings us to the following research problem: the voice synthesizers are appropriate for reading digital books in the Portuguese language? The objective of this study was to analyze and classify different software tools voice synthesizers in combination with software digital book readers to support accessibility to e-books in Portuguese. Through literature review were identified applications software voice synthesizers, composing the sample analyzed in this work. We used a simplified version of the method of Multiple Criteria Decision Support - MMDA, to assess these. In the research 12 were considered readers of e-books and 11 software voice synthesizer, tested with six formats of e-books (E-pub, PDF, HTML, DOC, TXT, and Mobi. In accordance with the results, the software Virtual Vision achieved the highest score. Relative to formats, it was found that the PDF has measured a better score when summed the results of the three synthesizers. In the studied universe contacted that many synthesizers simply cannot be used because they did not support the Portuguese language.

  7. High-Throughput Screening Across Quaternary Alloy Composition Space: Oxidation of (AlxFeyNi1-x-y)∼0.8Cr∼0.2.

    Science.gov (United States)

    Payne, Matthew A; Miller, James B; Gellman, Andrew J

    2016-09-12

    Composition spread alloy films (CSAFs) are commonly used as libraries for high-throughput screening of composition-property relationships in multicomponent materials science. Because lateral gradients afford two degrees of freedom, an n-component CSAF can, in principle, contain any composition range falling on a continuous two-dimensional surface through an (n - 1)-dimensional composition space. However, depending on the complexity of the CSAF gradients, characterizing and graphically representing this composition range may not be straightforward when n ≥ 4. The standard approach for combinatorial studies performed using quaternary or higher-order CSAFs has been to use fixed stoichiometric ratios of one or more components to force the composition range to fall on some well-defined plane in the composition space. In this work, we explore the synthesis of quaternary Al-Fe-Ni-Cr CSAFs with a rotatable shadow mask CSAF deposition tool, in which none of the component ratios are fixed. On the basis of the unique gradient geometry produced by the tool, we show that the continuous quaternary composition range of the CSAF can be rigorously represented using a set of two-dimensional "pseudoternary" composition diagrams. We then perform a case study of (AlxFeyNi1-x-y)∼0.8Cr∼0.2 oxidation in dry air at 427 °C to demonstrate how such CSAFs can be used to screen an alloy property across a continuous two-dimensional subspace of a quaternary composition space. We identify a continuous boundary through the (AlxFeyNi1-x-y)∼0.8Cr∼0.2 subspace at which the oxygen uptake into the CSAF between 1 and 16 h oxidation time increases abruptly with decreasing Al content. The results are compared to a previous study of the oxidation of AlxFeyNi1-x-y CSAFs in dry air at 427 °C.

  8. Высокая характеристическая температура лазера на квантовых точках InAs/GaAs/InGaAsP с длиной волны излучения около 1.5 мкм, синтезированного на подложке InP

    DEFF Research Database (Denmark)

    Zubov, F.I.; Semenova, Elizaveta; Kulkova, Irina

    2017-01-01

    We report on high temperature stability of a near-1.5 µm laser synthesized on an InP (001) substrate. Self-organized InAs quantum dots capped with a thin GaAs layer were used as an active region of the laser. An InGaAsP quaternary alloy having the bandgap energy of 1.15 eV was utilized as a waveg......We report on high temperature stability of a near-1.5 µm laser synthesized on an InP (001) substrate. Self-organized InAs quantum dots capped with a thin GaAs layer were used as an active region of the laser. An InGaAsP quaternary alloy having the bandgap energy of 1.15 eV was utilized...

  9. Perception of Paralinguistic Traits in Synthesized Voices

    DEFF Research Database (Denmark)

    Baird, Alice Emily; Hasse Jørgensen, Stina; Parada-Cabaleiro, Emilia

    2017-01-01

    Along with the rise of artificial intelligence and the internet-of-things, synthesized voices are now common in daily–life, providing us with guidance, assistance, and even companionship. From formant to concatenative synthesis, the synthesized voice continues to be defined by the same traits we...

  10. The variation of the energy gap with composition in the quaternary alloy system ZnTe/sub 1-2x/S/sub x/Se/sub x/

    International Nuclear Information System (INIS)

    Litvinchuk, A.P.; Vitrikhovskii, N.I.

    1983-01-01

    Studies are presented of photoluminescence spectra of the quaternary ZnTe/sub 1-2x/S/sub x/Se/sub x/ alloy (x = 0.05, 0.10, and 0.20). The determination of the energy gap variation with composition at 85 K is given. The nonlinear variation of the energy gap E/sub g/ with composition for the quaternary ZnTe/sub 1-2x/S/sub x/Se/sub x/ alloy may be interpreted in the framework of the pseudopotential theory based on the nonlinear crystal field properties

  11. Constraining fault activity by investigating tectonically-deformed Quaternary palaeoshorelines using a synchronous correlation method: the Capo D'Orlando Fault as a case study (NE Sicily, Italy)

    Science.gov (United States)

    Meschis, Marco; Roberts, Gerald P.; Robertson, Jennifer

    2016-04-01

    Long-term curstal extension rates, accommodated by active normal faults, can be constrained by investigating Late Quaternary vertical movements. Sequences of marine terraces tectonically deformed by active faults mark the interaction between tectonic activity, sea-level changes and active faulting throughout the Quaternary (e.g. Armijo et al., 1996, Giunta et al, 2011, Roberts et al., 2013). Crustal deformation can be calculated over multiple seismic cycles by mapping Quaternary tectonically-deformed palaeoshorelines, both in the hangingwall and footwall of active normal faults (Roberts et al., 2013). Here we use a synchronous correlation method between palaeoshorelines elevations and the ages of sea-level highstands (see Roberts et al., 2013 for further details) which takes advantage of the facts that (i) sea-level highstands are not evenly-spaced in time, yet must correlate with palaeoshorelines that are commonly not evenly-spaced in elevation, and (ii) that older terraces may be destroyed and/or overprinted by younger highstands, so that the next higher or lower paleoshoreline does not necessarily correlate with the next older or younger sea-level highstand. We investigated a flight of Late Quaternary marine terraces deformed by normal faulting as a result of the Capo D'Orlando Fault in NE Sicily (e.g. Giunta et al., 2011). This fault lies within the Calabrian Arc which has experienced damaging seismic events such as the 1908 Messina Straits earthquake ~ Mw 7. Our mapping and previous mapping (Giunta et al. (2011) demonstrate that the elevations of marine terraces inner edges change along the strike the NE - SW oriented normal fault. This confirms active deformation on the Capo D'Orlando Fault, strongly suggesting that it should be added into the Database of Individual Seismogenic Sources (DISS, Basili et al., 2008). Giunta et al. (2011) suggested that uplift rates and hence faults lip-rates vary through time for this examples. We update the ages assigned to

  12. Medical overuse and quaternary prevention in primary care - A qualitative study with general practitioners.

    Science.gov (United States)

    Alber, Kathrin; Kuehlein, Thomas; Schedlbauer, Angela; Schaffer, Susann

    2017-12-08

    Medical overuse is a topic of growing interest in health care systems and especially in primary care. It comprises both over investigation and overtreatment. Quaternary prevention strategies aim at protecting patients from unnecessary or harmful medicine. The objective of this study was to gain a deeper understanding of relevant aspects of medical overuse in primary care from the perspective of German general practitioners (GPs). We focused on the scope, consequences and drivers of medical overuse and strategies to reduce it (=quaternary prevention). We used the qualitative Grounded Theory approach. Theoretical sampling was carried out to recruit GPs in Bavaria, Germany. We accessed the field of research through GPs with academic affiliation, recommendations by interview partners and personal contacts. They differed in terms of primary care experience, gender, region, work experience abroad, academic affiliation, type of specialist training, practice organisation and position. Qualitative in-depth face-to-face interviews with a semi-structured interview guide were conducted (n = 13). The interviews were audiotaped and transcribed verbatim. Data analysis was carried out using open and axial coding. GPs defined medical overuse as unnecessary investigations and treatment that lack patient benefit or bear the potential to cause harm. They observed that medical overuse takes place in all three German reimbursement categories: statutory health insurance, private insurance and individual health services (direct payment). GPs criticised the poor acceptance of gate-keeping in German primary care. They referred to a low-threshold referral policy and direct patient access to outpatient secondary care, leading to specialist treatment without clear medical indication. The GPs described various direct drivers of medical overuse within their direct area of influence. They also emphasised indirect drivers related to system or societal processes. The proposed strategies for

  13. The impact of organisational culture on the adaptation of newly ...

    African Journals Online (AJOL)

    Usually newly employed nurses find adjusting to a work setting a challenging experience. Their successful adaptation to their work situation is greatly influenced by the socialisation process inherent in the organisational culture. The newly employed nurse often finds that the norms are unclear, confusing and restrictive.

  14. Raman assisted lightwave synthesized frequency sweeper

    DEFF Research Database (Denmark)

    Pedersen, Anders Tegtmeier; Rottwitt, Karsten

    2010-01-01

    We present a Lightwave Synthesized Frequency Sweeper comprising a Raman amplifier for loss compensation. The generated pulse train contains 123 pulses and has a flat signal level as well as a low noise level.......We present a Lightwave Synthesized Frequency Sweeper comprising a Raman amplifier for loss compensation. The generated pulse train contains 123 pulses and has a flat signal level as well as a low noise level....

  15. Assessment for markers of nephropathy in newly diagnosed type 2 ...

    African Journals Online (AJOL)

    Objective: To assess for markers of nephropathy in newly diagnosed type 2 diabetics, using blood pressure levels, endogenous creatinine clearance and urinary protein excretion as markers of renal disease. Study design: Ninety newly diagnosed type 2 diabetics were studied within 6 weeks of diagnosis. They were in ...

  16. Resistance to phenicol compounds following adaptation to quaternary ammonium compounds in Escherichia coli.

    Science.gov (United States)

    Soumet, C; Fourreau, E; Legrandois, P; Maris, P

    2012-07-06

    Bacterial adaptation to quaternary ammonium compounds (QACs) is mainly documented for benzalkonium chloride (BC) and few data are available for other QACs. The aim of this study was to assess the effects of repeated exposure to different quaternary ammonium compounds (QACs) on the susceptibility and/or resistance of bacteria to other QACs and antibiotics. Escherichia coli strains (n=10) were adapted by daily exposure to increasingly sub-inhibitory concentrations of a QAC for 7 days. Three QACs were studied. Following adaptation, we found similar levels of reduction in susceptibility to QACs with a mean 3-fold increase in the minimum inhibitory concentration (MIC) compared to initial MIC values, whatever the QAC used during adaptation. No significant differences in antibiotic susceptibility were observed between the tested QACs. Antibiotic susceptibility was reduced from 3.5- to 7.5-fold for phenicol compounds, β lactams, and quinolones. Increased MIC was associated with a shift in phenotype from susceptible to resistant for phenicol compounds (florfenicol and chloramphenicol) in 90% of E. coli strains. Regardless of the QAC used for adaptation, exposure to gradually increasing concentrations of this type of disinfectant results in reduced susceptibility to QACs and antibiotics as well as cross-resistance to phenicol compounds in E. coli strains. Extensive use of QACs at sub-inhibitory concentrations may lead to the emergence of antibiotic-resistant bacteria and may represent a public health risk. Published by Elsevier B.V.

  17. Radiocarbon ages of upper quaternary deposit in central Nepal and their geomorphological significance

    International Nuclear Information System (INIS)

    Yamanaka, Hidetsugu

    1982-01-01

    The author visited Nepal from October, 1980, to February, 1981, investigated the geomorphology and upper Quaternary geology in Central Nepal, and collected a number of samples for radiocarbon dating. After returning to his university, he dated ten samples by himself. In Nepal, radiocarbon age has been scarcely reported as yet, besides in Kathmandu valley. Therefore, the author's ten data of the age are very important for the late Quaternary chronological study of Nepal Himalayas. In this paper, the author describes sampling localities and horizons, dating results and their geomorphological significance. These ten samples included Pokhara valley, Marsyandi Kohla, Modi Khola, Madi Khola and Muktinath samples. Some conclusion was derived as for the geomorphological development in central Nepal: The last Himalayan glacial age had already ended before 9,000 yr BP (years before A.D. 1950); In the Midland region, from 4,300 to 600 yr BP, some large-scale mudflows broke out nearly contemporaneously in the upper valleys, and they flowed down torrentially and catastrophically to deposit in the middle course of rivers. But the cause of vast quantity of material suddenly brought down from the Great Himalayas has been still left unexplained. The conclusion like this also was able to be applied to the middle Marsyandi Khola and the Pokhara valley. The wide-spread schema that the river was aggraded in the glacial age and degraded in the interglacial age may not be applicable to the rivers in the Midland region of Nepal Himalayas. (Wakatsuki, Y.)

  18. Structural contour, isopach and feature maps of quaternary sediments in Western Lake Ontario

    International Nuclear Information System (INIS)

    Lewis, C.F.M.; King, E.L.; Todd, B.J.; Blasco, S.M.

    1995-06-01

    A systematic high-resolution acoustic reconnaissance survey of Quaternary sediments (> 50 m thick, in places) and the underlying bedrock surface was completed for western Lake Ontario between Burlington and Port Hope, Ontario, to determine if geophysical lineaments through the area of Pickering and Darlington nuclear power stations are potentially seismically active. A total of 2530 line-km of data were obtained along N-S and E-W lines spaced 10 and 5 km respectively, using a high-resolution subbottom profiler (boomer and IKB-SEISTEC), a 100 kHz sidescan sonar (150-m range) with 3.5 kHz profiler, a 10 or 40 cu. in. sleeve gun seismic reflection system, and, intermittently, a marine magnetometer. Six piston cores up to 15-m long were collected to compare sediment lithology with key regional seismic reflectors. Sediments deposited over the past 13,000 years were imaged with vertical resolution in the order of 10-30 cm just below the lakebed and less than 1 m at the bedrock surface; resolution for the sleeve gun system is approximately 3-5 m. Digital processing and rescaling of selected seismic profiles aided interpretation. Structural contour maps for three Quaternary sequence boundaries and the bedrock surface were generated together with the related sequence isopach maps. Three additional maps portray lakebed features identified on sidescan sonar records and subsurface features identified on seismic profiles. All maps are at 1:250,000 scale. (author). 2 tabs., 48 figs., 12 maps

  19. Determination of selected quaternary ammonium compounds by liquid chromatography with mass spectrometry. Part II. Application to sediment and sludge samples in Austria

    International Nuclear Information System (INIS)

    Martinez-Carballo, Elena; Gonzalez-Barreiro, Carmen; Sitka, Andrea; Kreuzinger, Norbert; Scharf, Sigrid; Gans, Oliver

    2007-01-01

    Soxhlet extraction and high-performance liquid chromatography (HPLC) coupled to tandem mass spectrometry detection (MS/MS) was used for the determination of selected quaternary ammonium compounds (QACs) in solid samples. The method was applied for the determination of alkyl benzyl, dialkyl and trialkyl quaternary ammonium compounds in sediment and sludge samples in Austria. The overall method quantification limits range from 0.6 to 3 μg/kg for sediments and from 2 to 5 μg/kg for sewage sludges. Mean recoveries between 67% and 95% are achieved. In general sediments were especially contaminated by C12 chain benzalkonium chloride (BAC-C12) as well as by the long C-chain dialkyldimethylammonium chloride (DDAC-C18) with a maximum concentration of 3.6 mg/kg and 2.1 mg/kg, respectively. Maxima of 27 mg/kg for DDAC-C10, 25 mg/kg for BAC-C12 and 23 mg/kg for BAC-C14 were determined for sludge samples. The sums of the 12 selected target compounds range from 22 mg/kg to 103 mg/kg in the sludge samples. - The presence of quaternary ammonium surfactants in sediment and sludge samples is reported for the first time in Austria

  20. Quantification of synthesized hydration products using synchrotron microtomography and spectral analysis

    Energy Technology Data Exchange (ETDEWEB)

    Deboodt, Tyler; Ideker, Jason H.; Isgor, O. Burkan; Wildenschild, Dorthe

    2017-12-01

    The use of x-ray computed tomography (CT) as a standalone method has primarily been used to characterize pore structure, cracking and mechanical damage in cementitious systems due to low contrast in the hydrated phases. These limitations have resulted in the inability to extract quantifiable information on such phases. The goal of this research was to address the limitations caused by low contrast and improving the ability to distinguish the four primary hydrated phases in portland cement; C-S-H, calcium hydroxide, monosulfate, and ettringite. X-ray CT on individual layers, binary mixtures of phases, and quaternary mixtures of phases to represent a hydrated portland cement paste were imaged with synchrotron radiation. Known masses of each phase were converted to a volume and compared to the segmented image volumes. It was observed that adequate contrast in binary mixing of phases allowed for segmentation, and subsequent image analysis indicated quantifiable volumes could be extracted from the tomographic volume. However, low contrast was observed when C-S-H and monosulfate were paired together leading to difficulties segmenting in an unbiased manner. Quantification of phases in quaternary mixtures included larger errors than binary mixes due to histogram overlaps of monosulfate, C-S-H, and calcium hydroxide.

  1. Effect of zinc oxide nanoparticles synthesized by a precipitation

    Indian Academy of Sciences (India)

    ZnO nanoparticles were synthesized by a precipitation method in aqueous media from zinc nitrate hexahydrate and sodium hydroxide. The synthesized ZnO nanoparticles exhibited a crystalline structure with hexagonal structure of the wurtzite. The morphology of the synthesized ZnO nanoparticles presented a spherical ...

  2. Isothermal Vapor-Liquid Equilibrium in the Quaternary Water + 2-Propanol + Acetic Acid + Isopropyl Acetate System with Chemical Reaction

    Czech Academy of Sciences Publication Activity Database

    Teodorescu, M.; Aim, Karel; Wichterle, Ivan

    2001-01-01

    Roč. 46, č. 2 (2001), s. 261-266 ISSN 0021-9568 R&D Projects: GA ČR GA203/98/1446 Institutional research plan: CEZ:AV0Z4072921 Keywords : vapor-liquid equilibrium * quaternary water Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.960, year: 2001

  3. Lattice vibrations study of Ga{sub 1-x}In{sub x}As{sub y}Sb{sub 1-y} quaternary alloys with low (In, As) content grown by liquid phase epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Olvera-Herandez, J [Centro de Investigacion en Dispositivos Semiconductores (CIDS), BUAP, Puebla, Pue. 72570 (Mexico); Olvera-Cervantes, J [Centro de Investigacion en Dispositivos Semiconductores (CIDS), BUAP, Puebla, Pue. 72570 (Mexico); Rojas-Lopez, M [Centro de Investigacion en BiotecnologIa Aplicada (CIBA), IPN, Tlaxcala, Tlax. 72160 (Mexico); Navarro-Contreras, H [Instituto de Investigacion en Comunicacion Optica (IICO), UASLP, 78100, San Luis PotosI, S.L.P. (Mexico); Vidal, M A [Instituto de Investigacion en Comunicacion Optica (IICO), UASLP, 78100, San Luis PotosI, S.L.P. (Mexico); Anda, F de [Instituto de Investigacion en Comunicacion Optica (IICO), UASLP, 78100, San Luis PotosI, S.L.P. (Mexico)

    2006-01-01

    Raman scattering spectroscopy was used to measure and analyze the lattice vibrations in some quaternary Ga{sub 1-x}In{sub x}As{sub y}Sb{sub 1-y} alloys with low (In, As) contents (0.03 quaternary layer lattice matched to the GaSb substrate as obtained from the (004) reflection. The experimental diffractograms were simulated to estimate alloy composition, thickness and lattice mismatch of the layer. Raman scattering results show phonon frequencies associated to the TO and LO GaAs-like modes as well as GaSb + InAs-like mode, which are characteristic of this quaternary alloy. The As content dependence of the phonon frequency measured in this alloy for low (In, As) contents agree well with the modified Random-Element Isodisplacement (REI) model and also with other available experimental reports. This method can also be used to estimate alloy compositions for this kind of quaternary alloys.

  4. 14 CFR 26.39 - Newly produced airplanes: Fuel tank flammability.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Newly produced airplanes: Fuel tank... Tank Flammability § 26.39 Newly produced airplanes: Fuel tank flammability. (a) Applicability: This... Series 767 Series (b) Any fuel tank meeting all of the criteria stated in paragraphs (b)(1), (b)(2) and...

  5. Testing MODFLOW-LGR for simulating flow around Buried Quaternary valleys - synthetic test cases

    DEFF Research Database (Denmark)

    Vilhelmsen, Troels Norvin; Christensen, Steen

    In Denmark the water supply is entirely based on ground water. In some parts of the country these resources are found in buried quaternary tunnel valleys. Intensive mapping has shown that the valleys typically have a complex internal hydrogeology with multiple cut and ­fill structures....... The administration of groundwater resources has been based on simulations using regional scale groundwater models. However, regional scale models have difficulties with accurately resolving the complex geology of the buried valleys, which bears the risk of poor model predictions of local scale effects of groundwater...

  6. Reporter-free potentiometric sensing of boronic acids and their reactions by using quaternary ammonium salt-functionalized polymeric liquid membranes.

    Science.gov (United States)

    Wang, Xuewei; Yue, Dengfeng; Lv, Enguang; Wu, Lei; Qin, Wei

    2014-02-18

    The tremendous applications of boronic acids (BAs) in chemical sensing, medical chemistry, molecular assembly, and organic synthesis lead to an urgent demand for developing effective sensing methods for BAs. This paper reports a facile and sensitive potentiometric sensor scheme for heterogeneous detection of BAs based on their unexpected potential responses on quaternary ammonium salt-doped polymeric liquid membranes. (11)B NMR data reveal that a quaternary ammonium chloride can trigger the hydrolysis of an electrically neutral BA in an aprotic solvent. Using the quaternary ammonium salt as the receptor, the BA molecules can be extracted from the sample solution into the polymeric membrane phase and undergo the concomitant hydrolysis. Such salt-triggered hydrolysis generates H(+) ions, which can be coejected into the aqueous phase with the counterions (e.g., Cl(-)) owing to their high hydrophilicities. The perturbation on the ionic partition at the sample-membrane interface changes the phase boundary potential and thus enables the potentiometric sensing of BAs. In contrast to other transduction methods for BAs, for which labeled or separate reporters are exclusively required, the present heterogeneous sensing scheme allows the direct detection of BAs without using any reporter molecules. This technique shows superior detection limits for BAs (e.g., 1.0 × 10(-6) M for phenylboronic acid) as compared to previously reported methods based on colorimetry, fluorimetry, and mass spectrometry. The proposed sensing strategy has also been successfully applied to potentiometric indication of the BA reactions with hydrogen peroxide and saccharides, which allows indirect and sensitive detection of these important species.

  7. An insight into the mechanism of charge-transfer of hybrid polymer:ternary/quaternary chalcopyrite colloidal nanocrystals

    Directory of Open Access Journals (Sweden)

    Parul Chawla

    2014-08-01

    Full Text Available In this work, we have demonstrated the structural and optoelectronic properties of the surface of ternary/quaternary (CISe/CIGSe/CZTSe chalcopyrite nanocrystallites passivated by tri-n-octylphosphine-oxide (TOPO and tri-n-octylphosphine (TOP and compared their charge transfer characteristics in the respective polymer: chalcopyrite nanocomposites by dispersing them in poly(3-hexylthiophene polymer. It has been found that CZTSe nanocrystallites due to their high crystallinity and well-ordered 3-dimensional network in its pristine form exhibit a higher steric- and photo-stability, resistance against coagulation and homogeneity compared to the CISe and CIGSe counterparts. Moreover, CZTSe nanocrystallites display efficient photoluminescence quenching as evident from the high value of the Stern–Volmer quenching constant (KSV and eventually higher charge transfer efficiency in their respective polymer P3HT:CZTSe composites. We modelled the dependency of the charge transfer from the donor and the charge separation mechanism across the donor–acceptor interface from the extent of crystallinity of the chalcopyrite semiconductors (CISe/CIGSe/CZTSe. Quaternary CZTSe chalcopyrites with their high crystallinity and controlled morphology in conjunction with regioregular P3HT polymer is an attractive candidate for hybrid solar cells applications.

  8. An insight into the mechanism of charge-transfer of hybrid polymer:ternary/quaternary chalcopyrite colloidal nanocrystals.

    Science.gov (United States)

    Chawla, Parul; Singh, Son; Sharma, Shailesh Narain

    2014-01-01

    In this work, we have demonstrated the structural and optoelectronic properties of the surface of ternary/quaternary (CISe/CIGSe/CZTSe) chalcopyrite nanocrystallites passivated by tri-n-octylphosphine-oxide (TOPO) and tri-n-octylphosphine (TOP) and compared their charge transfer characteristics in the respective polymer: chalcopyrite nanocomposites by dispersing them in poly(3-hexylthiophene) polymer. It has been found that CZTSe nanocrystallites due to their high crystallinity and well-ordered 3-dimensional network in its pristine form exhibit a higher steric- and photo-stability, resistance against coagulation and homogeneity compared to the CISe and CIGSe counterparts. Moreover, CZTSe nanocrystallites display efficient photoluminescence quenching as evident from the high value of the Stern-Volmer quenching constant (K SV) and eventually higher charge transfer efficiency in their respective polymer P3HT:CZTSe composites. We modelled the dependency of the charge transfer from the donor and the charge separation mechanism across the donor-acceptor interface from the extent of crystallinity of the chalcopyrite semiconductors (CISe/CIGSe/CZTSe). Quaternary CZTSe chalcopyrites with their high crystallinity and controlled morphology in conjunction with regioregular P3HT polymer is an attractive candidate for hybrid solar cells applications.

  9. Bohr effect of human hemoglobin: Separation of tertiary and quaternary contributions based on the Wyman equation.

    Science.gov (United States)

    Okonjo, Kehinde Onwochei

    2017-09-01

    As a prelude to separating tertiary from quaternary structure contributions to the Bohr effect, we employed the Wyman equation to analyze Bohr data for human hemoglobin to which 2,3-bisphosphoglycerate, 2,3-BPG, is bound. Changes in the pK a s of the histidine Bohr groups result in a net reduction of their contributions to the Bohr effect at pH 7.4 compared to their contributions in stripped hemoglobin. The non-histidine 2,3-BPG binding groups - the β-chain terminal amino group and Lys82β - make negative and positive contributions, respectively, to the Bohr effect. The final result is that the Bohr effect at physiological pH is higher for 2,3-BPG bound compared to stripped hemoglobin. Contributions linked to His2β, His77β and His143β enable us to separate tertiary from quaternary Bohr contributions in stripped and in 2,3-BPG bound hemoglobin. Both contributions serve to make the Bohr effect for 2,3-BPG bound hemoglobin higher than for stripped hemoglobin at physiological pH. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Late quaternary palaeo-oceanography and palaeo-climatology from sediment cores of the eastern Arctic Ocean

    International Nuclear Information System (INIS)

    Pagels, U.; Koehler, S.

    1991-01-01

    Box cores recovered along a N-S transect in the Eurasian Basin allow the establishment of a time scale for the Late Quaternary history of the Arctic Ocean, based on stable oxygen isotope stratigraphy and AMS 14 C dating of planktonic foraminifers (N. pachyderma I.c.). This high resolution stratigraphy, in combination with sedimentological investigations (e.g. coarse fraction analysis, carbonate content, productivity of foraminifers), was carried out to reconstruct the glacial and inter-glacial Arctic Ocean palaeo-environment The sediment cores, which can be correlated throughout the sampling area in the Eastern Arctic Ocean, were dated as representing oxygen isotope stages 1 to 4/5. The sedimentation rates varied between a few mm/ka in glacials and approximately one cm/ka during the Holocene. The sediments allow a detailed sedimentological description of the depositional regime and the palaeo-oceanography of the Eastern Arctic Ocean. Changing ratios of biogenic and lithogenic components in the sediments reflect variations in the oceanographic circulation pattern in the Eurasian Basin during the Late Quaternary. Carbonate content (1-9wt.%), productivity of foraminifers (high in interglacial, low in glacial stages) and the terrigenous components are in good correlation with glacial and inter-glacial climatic fluctuations

  11. Paleontology to policy: the Quaternary history of Southeast Asian tapirs (Tapiridae) in relation to large mammal species turnover, with a proposal for conservation of Malayan tapir by reintroduction to Borneo.

    Science.gov (United States)

    Cranbrook, Earl Of; Piper, Philip J

    2013-03-01

    The Southeast Asian zoogeographical region is divided into Indochinese, Sundaic and Philippine subregions. Two clades of tapirs, Tapirus spp., have been recognized in Quaternary Southeast Asia. A review of sites at which they occurred shows that representatives of both clades, one of which was the ancestral Malayan tapir Tapirus indicus, co-existed with a diversity of other Pleistocene mammal megafauna. The process of replacement of archaic large mammals was progressive and prolonged through the Quaternary. Zooarcheological investigation has extended knowledge of the former occurrence and distribution of tapirs and other large mammals of the region, with discoveries beyond the outer limits of their previously known ranges. These large mammals were subjected to paleoenvironmental changes as a consequence of the Quaternary cycles of glacial and interglacial periods. Archeological evidence suggests that hunting pressure has intensified the effects of altered environments, leading ultimately to the local disappearance of the Malayan tapir in most of Southeast Asia, including Borneo. The survival of the Malayan tapir through the Quaternary until the present shows that the species is both resilient to environmental change and flexible in its ecological re'uirements and, given proper protection, could continue to inhabit tropical Southeast Asia. To assist the species conservation, reintroduction is proposed from the remaining range of Malayan tapir in the wild, to suitable sites of past occurrence in Borneo, where these ancient survivors of the Quaternary megafauna can be accommodated and safeguarded alongside other forms of land usage. © 2012 Wiley Publishing Asia Pty Ltd, ISZS and IOZ/CAS.

  12. Quaternary structure and spin state of human fetal methemoglobin

    International Nuclear Information System (INIS)

    Chevion, M.; Navok, T.; Ilan, Y.A.; Czapski, G.

    1981-01-01

    Using the pulse-radiolysis technique, solutions of fetal human methemoglobin were irradiated in order to reduce a single heme-iron within the protein tetramers. The valence-hybrids thus formed ere reacted wjth oxygen. Kinetics of the reactions were studied. The effects of p and inositol-hexaphosphate (IHP) were examined. The kinetics of the ligation of oxygen to stripped valence-hybrids showed a single-phase behaviour at the pH range 7-9. As the pH was lowered below 6.5, a second slower phase became apparent. This slow phase consisted of approximately 50% at pH 5.8. In the presence of IHP above pH 7.4, the kinetics of oxygen-binding was of a single-phase. As the pH was lowered a transition to a second, slower phase was noticed. Below pH 7 the slower phase was the only detectable one. The analysis of the relative contribution of the faster phase to the total reaction, as a function of the pH, showed a typical sigmoidal transition curve characterized by a pK = 7.2 and a Hill parameter n = 3.06. On this basis it is concluded that stripped, fetal human methemoglobin resides in an R quaternary structure while the presence of IHP stabilizes the T structure at pH below 7.2. The switch between the high spin aquomet- and the low spin hydroxymet-derivatives of adult and fetal human hemoglobins was studied optically in detail. These switches were found to be only slightly affected by IHP, and exhibited very low cooperativity (pK = 8.04; n = 1.1 and pK = 8.10; n = 1.3 for adult methemoglobin when stripped and in the presence of IHP, respectively; pK = 8.18; n = 1.11 and pK = 8.21; n = 1.28 for fetal methemoglobin when stripped and in the presence of IHP, respectively). These findings lead to the conclusion that the transition between quaternary structures in either human or fetal methemoglobins is not coupled to the switch of the spin state of the ferric heme. (author)

  13. Quaternary alkylammonium and alkylphosphonium pertechnetates. Application to pertechnetate ion-selective electrodes

    International Nuclear Information System (INIS)

    German, K.E.; Dorokhov, A.V.; Tarasov, A.V.; Baulin, V.E.; Peretroukhine, V.; Tsivadze, A.Yu.; Kopytin, A.V.; Politov, Yu.; Pyatova, E.N.

    2005-01-01

    Pertechnetate ion-selective PVC membrane electrodes based on quaternary alkylammonium and phosphonium salts (bromides and pertechnetates) were examined. The most favorable ionophore was tetradecyltrimethylammonium bromide. The response function was linear within the concentration range 10 -2 -10 -6 mol/L and the slope was 52 mV/pTcO 4 . The detection limit remained at 5x10 -7 mol/L. The selectivity and response time of the electrodes was studied and it was found that the electrodes exhibited high selectivity to TcO 4 - -anion against the main inorganic components of radioactive waste solutions and environmental waters (nitrate, sulfate, chloride and others). The electrodes response was stable over a wide pH range. (author)

  14. In vitro antibacterial activity of a novel resin-based pulp capping material containing the quaternary ammonium salt MAE-DB and Portland cement.

    Science.gov (United States)

    Yang, Yanwei; Huang, Li; Dong, Yan; Zhang, Hongchen; Zhou, Wei; Ban, Jinghao; Wei, Jingjing; Liu, Yan; Gao, Jing; Chen, Jihua

    2014-01-01

    Vital pulp preservation in the treatment of deep caries is challenging due to bacterial infection. The objectives of this study were to synthesize a novel, light-cured composite material containing bioactive calcium-silicate (Portland cement, PC) and the antimicrobial quaternary ammonium salt monomer 2-methacryloxylethyl dodecyl methyl ammonium bromide (MAE-DB) and to evaluate its effects on Streptococcus mutans growth in vitro. The experimental material was prepared from a 2 : 1 ratio of PC mixed with a resin of 2-hydroxyethylmethacrylate, bisphenol glycerolate dimethacrylate, and triethylene glycol dimethacrylate (4 : 3 : 1) containing 5 wt% MAE-DB. Cured resin containing 5% MAE-DB without PC served as the positive control material, and resin without MAE-DB or PC served as the negative control material. Mineral trioxide aggregate (MTA) and calcium hydroxide (Dycal) served as commercial controls. S. mutans biofilm formation on material surfaces and growth in the culture medium were tested according to colony-forming units (CFUs) and metabolic activity after 24 h incubation over freshly prepared samples or samples aged in water for 6 months. Biofilm formation was also assessed by Live/Dead staining and scanning electron microscopy. S. mutans biofilm formation on the experimental material was significantly inhibited, with CFU counts, metabolic activity, viability staining, and morphology similar to those of biofilms on the positive control material. None of the materials affected bacterial growth in solution. Contact-inhibition of biofilm formation was retained by the aged experimental material. Significant biofilm formation was observed on MTA and Dycal. The synthesized material containing HEMA-BisGMA-TEGDMA resin with MAE-DB as the antimicrobial agent and PC to support mineralized tissue formation inhibited S. mutans biofilm formation even after aging in water for 6 months, but had no inhibitory effect on bacteria in solution. Therefore, this material shows

  15. Chrysosplenium japonicum (Saxifragaceae, Newly Recorded from Taiwan

    Directory of Open Access Journals (Sweden)

    Tian-Chuan Hsu

    2011-11-01

    Full Text Available Chrysosplenium japonicum (Maxim. Makino (Saxifragaceae is newly recorded from northeastern Taiwan. Description, color photos and a key to the Chrysosplenium species in Taiwan are provided.

  16. Variable dimensionality and framework found in a series of quaternary zinc selenites, A2Zn3(SeO3)4·xH2O (A = Na, Rb, and Cs; 0≤x≤1) and Cs2Zn2(SeO3)3·2H2O

    International Nuclear Information System (INIS)

    Lü, Minfeng; Jo, Hongil; Oh, Seung-Jin; Ok, Kang Min

    2017-01-01

    Five new alkali metal zinc selenites, A 2 Zn 3 (SeO 3 ) 4 ·xH 2 O (A = Na, Rb, and Cs; 0≤x≤1) and Cs 2 Zn 2 (SeO 3 ) 3 ·2H 2 O have been synthesized by heating a mixture of ZnO, SeO 2 and A 2 CO 3 (A = Na, Rb, and Cs), and characterized by X-ray diffraction (XRD) and spectroscopic analyses techniques. All of the reported materials revealed a rich structural chemistry with different frameworks and connection modes of Zn 2+ . While Rb 2 Zn 3 (SeO 3 ) 4 and Cs 2 Zn 3 (SeO 3 ) 4 ·H 2 O revealed three-dimensional frameworks consisting of isolated ZnO 4 tetrahedra and SeO 3 polyhedra, Na 2 Zn 3 (SeO 3 ) 4 , Cs 2 Zn 3 (SeO 3 ) 4 , and Cs 2 Zn 2 (SeO 3 ) 3 ·2H 2 O contained two-dimensional [Zn 3 (SeO 3 ) 4 ] 2- layers. Specifically, whereas isolated ZnO 4 tetrahedra and SeO 3 polyhedra are arranged into two-dimensional [Zn 3 (SeO 3 ) 4 ] 2- layers in two cesium compounds, circular [Zn 3 O 10 ] 14- chains and SeO 3 linkers are formed in two-dimensional [Zn 3 (SeO 3 ) 4 ] 2- layers in Na 2 Zn 3 (SeO 3 ) 4 . Close structural examinations suggest that the size of alkali metal is significant in determining the framework geometry as well as connection modes of transition metal cations. - Graphical abstract: Variable dimensions and frameworks were found in a series of quaternary zinc selenites, A 2 Zn 3 (SeO 3 ) 4 (A = Na, Rb and Cs). - Highlights: • Five novel quaternary zinc selenites are synthesized. • All the selenites with different structures contain polarizable d 10 and lone pair cations. • The size of alkali metal cations is significant in determining the framework geometry.

  17. Being a team leader: newly registered nurses relate their experiences.

    Science.gov (United States)

    Ekström, Louise; Idvall, Ewa

    2015-01-01

    This paper presents a study that explores how newly qualified registered nurses experience their leadership role in the ward-based nursing care team. A nurse's clinical leadership affects the quality of care provided. Newly qualified nurses experience difficulties during the transition period from student to qualified professional and find it challenging to lead nursing care. Twelve nurses were interviewed and the transcribed texts analysed using qualitative content analysis to assess both manifest and latent content. Five themes were identified: feeling stranded; forming well-functioning teams; learning to lead; having the courage, strength, and desire to lead; and ensuring appropriate care. The findings indicate that many factors limit nurses' leadership but some circumstances are supportive. The leadership prerequisites for newly registered nurses need to improve, emphasizing different ways to create a supportive atmosphere that promotes professional development and job satisfaction. To increase nurse retention and promote quality of care, nurse managers need to clarify expectations and guide and support newly qualified nurses in a planned way. © 2013 John Wiley & Sons Ltd.

  18. People newly in love are more responsive to positive feedback.

    Science.gov (United States)

    Brown, Cassandra L; Beninger, Richard J

    2012-06-01

    Passionate love is associated with increased activity in dopamine-rich regions of the brain. Increased dopamine in these regions is associated with a greater tendency to learn from reward in trial-and-error learning tasks. This study examined the prediction that individuals who were newly in love would be better at responding to reward (positive feedback). In test trials, people who were newly in love selected positive outcomes significantly more often than their single (not in love) counterparts but were no better at the task overall. This suggests that people who are newly in love show a bias toward responding to positive feedback, which may reflect a general bias towards reward-seeking.

  19. Significance of relic carbonate deposits along the central and southwestern margin of India for late Quaternary environmental and sea level changes

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Montaggioni, L.; Vora, K.H.; Almeida, F.; Rao, K.M.; Rajagopalan, G.

    Environmental and sea level indicators were investigated using dredge samples from late Quaternary carbonate deposits along the shelf break between Goa and Cape Comorin, India. Geomorphic features in the area were identified from sonar profiles...

  20. Methane hydrates in quaternary climate change

    International Nuclear Information System (INIS)

    Kennett, J. P.; Hill, T. M.; Behl, R. J.

    2005-01-01

    The hydrate reservoir in marine sediments is known to contain a large volume of exchangeable carbon stored as solid methane hydrate and associated free gas. This reservoir has been shown to be potentially unstable in response to changing intermediate water temperature and sea level (pressure). Evidence continues to grow for past episodes of major methane release at times of climatic warming. Yet few studies of late Quaternary climate change include methane hydrates as an integral part of the global climate system, in spite of the largest known oscillations at this time in sea level and upper ocean temperature changes for the Cenozoic or earlier, conditions that favor instability of the methane hydrate reservoir. Abrupt increases in atmospheric methane recorded in polar ice cores are widely believed to have resulted, not from ocean-floor methane degassing, but instead from continental wetland activation, a hypothesis thus far unsupported by geological data. Furthermore, as part of this Wetland Methane Hypothesis, the abrupt methane increases have been seen as a response to climatic warming rather than contributing significantly to the change. An alternative view (formulated as the Clathrate Gun Hypothesis) is that the speed, magnitude and timing of abrupt climate change in the recent geologic past are consistent with the process of major degassing of methane hydrates. We summarize aspects of this hypothesis here and needs to test this hypothesis. (Author)

  1. Electrical imaging and self-potential surveys to study the geological setting of the quaternary slope deposits in the Agri high valley (Southern Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Giano, S I; Schiattarella, M [Basilicata Univ., Potenza (Italy). Centro di Geodinamica; Lapenna, V; Piscitelli, S [Consiglio Nazionale delle Ricerche, Tito, PZ (Italy). Ist. di Metodologie Avanzate di Analisi Ambientale

    2000-04-01

    The paper presents the results of a geophysical survey carried out to outline the structural modelling of quarternary slope deposits in the northern part of Agri high valley (Basilicata region, Italy). Quaternary folding and brittle deformations of the subaerial slope deposits have been studied combining electrical imaging and self-potential surveys with geological structural analysis. This integrated approach indicates that the area underwent both transpressional and transtensional tectonics during Pleistocene times as testified by the existence of a push up structure in the basement buried by deformed Quaternary breccias. On this basis, the valley appears to be a more complex structure than a simple extensional graben, as traditionally assumed in the literature.

  2. (Surfactant + polymer) interaction parameter studied by (liquid + liquid) equilibrium data of quaternary aqueous solution containing surfactant, polymer, and salt

    Energy Technology Data Exchange (ETDEWEB)

    Foroutan, Masumeh [Physical Chemistry Department, School of Chemistry, College of Science, University of Tehran, 14155-6455 Tehran (Iran, Islamic Republic of)], E-mail: foroutan@khayam.ut.ac.ir; Heidari, Nosrat; Mohammadlou, Maryam [Chemistry Department, Faculty of Science, Uremia University, Uremia (Iran, Islamic Republic of); Sojahrood, Amin Jafari [Physics Department, Faculty of Science, Uremia University, Uremia (Iran, Islamic Republic of)

    2009-02-15

    (Liquid + liquid) equilibrium (LLE) data of quaternary aqueous system containing polyoxyethylene (20) cetyl ether (with abbreviation name Brij 58, non-ionic surfactant), diammonium hydrogen phosphate, and poly ethylene glycol (PEG) with three molar masses {l_brace}M{sub W} = (1000, 6000, and 35,000) g . mol{sup -1}{r_brace} have been determined experimentally at T = 313.15 K. Furthermore, the Flory-Huggins theory with two electrostatic terms (Debye-Hueckel and Pitzer-Debye-Hueckel equations) have been used to calculate the phase behavior of the quaternary systems and (surfactant + polymer) interaction parameter as well as interaction parameters between other species. Temperature dependency of the parameters of the Flory-Huggins theory has been obtained. Also an effort have been done to show that addition of PEG as well as increasing the temperature can shift the binodal curves of the ternary aqueous system containing surfactant and salt to lower mole fraction of salt. Also the effect of polymer molar mass on the binodal diagram displacement has been discussed.

  3. Thermoluminescence properties of Li2B4O7:Cu, B phosphor synthesized using solution combustion technique

    International Nuclear Information System (INIS)

    Ozdemir, A.; Altunal, V.; Kurt, K.; Depci, T.; Yu, Y.; Lawrence, Y.; Nur, N.; Guckan, V.; Yegingil, Z.

    2017-01-01

    To determine the effects of various concentrations of the activators copper (Cu) and boron (B) on the thermoluminescence (TL) properties of lithium tetraborate, the phosphor was first synthesized and doped with five different concentrations of copper (0.1–0.005 wt%) using solution combustion method. 0.01 wt% Cu was the concentration which showed the most significant increase in the sensitivity of the phosphor. The second sort of Li 2 B 4 O 7 :Cu material was prepared by adding B (0.001–0.03 wt%) to it. The newly developed copper-boron activated lithium tetraborate (Li 2 B 4 O 7 :Cu, B) material with 0.01 wt% Cu and 0.001 wt% B impurity concentrations was shown to have promise as a TL phosphor. The material formation was examined using powder x-Ray Diffraction (XRD) analysis and Scanning Electron Microscope (SEM) imaging. Fourier Transform Infrared (FT-IR) spectrum of the synthesized polycrystalline powder sample was also recorded. The TL glow curves were analyzed to determine various dosimetric characteristics of the synthesized luminophosphors. The dose response increased in a “linear” way with the beta-ray exposure between 0.1–20 Gy, a dose range being interested in medical dosimetry. The response with changing photon and electron energy was studied. The rate of decay of the TL signal was investigated both for dark storage and under direct sunlight. Li 2 B 4 O 7 :Cu, B showed no individual variation of response in 9 recycling measurements. The fluorescence spectrum was determined. The kinetic parameters were estimated by different methods and the results discussed. The studied properties of synthesized Li 2 B 4 O 7 :Cu, B were found all favorable for dosimetric purposes. - Highlights: • Li 2 B 4 O 7 :Cu, B synthesis using solution combustion method with various concentrations. • Structure analysis of Li 2 B 4 O 7 :Cu, B using XRD, SEM and FTIR methods. • Investigation of thermoluminescent properties of Li 2 B 4 O 7 :Cu, B. • Relatively good

  4. Workplace Violence and Job Outcomes of Newly Licensed Nurses

    OpenAIRE

    Chang, Hyoung Eun; Cho, Sung-Hyun

    2016-01-01

    Purpose: The purpose of this study was to examine the prevalence of workplace violence toward newly licensed nurses and the relationship between workplace violence and job outcomes. Methods: An online survey was conducted of newly licensed registered nurses who had obtained their license in 2012 or 2013 in South Korea and had been working for 5–12 months after first being employed. The sample consisted of 312 nurses working in hospitals or clinics. The Copenhagen Psychosocial Questionnaire...

  5. An investigation of the Pd-Ag-Ru-Gd quaternary system phase diagram

    International Nuclear Information System (INIS)

    Zhang Kanghou; Xu Yun

    2005-01-01

    On the basis of the Ag-Pd-Gd, Ag-Ru-Gd and Pd-Ru-Gd ternary systems, the partial phase diagram of Pd-Ag-Ru-Gd (Gd 3 Gd and Ag 51 Gd 14 ; five two-phase regions: Pd(Ag) + (Ru), Pd(Ag) + Ag 51 Gd 14 (Ru) + Ag 51 Gd 14 , Pd(Ag) + Pd 3 Gd and (Ru) + Pd 3 Gd; three three-phase regions: Pd(Ag) + Pd 3 Gd + (Ru), Pd(Ag) + Ag 51 Gd 14 + (Ru) and (Ru) + Ag 51 Gd 14 + Pd 3 Gd; one four-phase region Pd(Ag) + (Ru) + Ag 51 Gd 14 + Pd 3 Gd. No new quaternary intermetallic phase has been found

  6. Quaternary Geologic Map of the Lake of the Woods 4 Degrees x 6 Degrees Quadrangle, United States and Canada

    Science.gov (United States)

    Sado, Edward V.; Fullerton, David S.; Goebel, Joseph E.; Ringrose, Susan M.; Edited and Integrated by Fullerton, David S.

    1995-01-01

    The Quaternary Geologic Map of the Lake of the Woods 4 deg x 6 deg Quadrangle, United States and Canada, was mapped as part of the U.S. Geological Survey Quaternary Geologic Atlas of the United States map series (Miscellaneous Investigations Series I-1420, NM-15). The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the 'ground' on which we walk, the 'dirt' in which we dig foundations, and the 'soil' in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale. This map is a product of collaboration of the Ontario Geological Survey, the Minnesota Geological Survey, the Manitoba Department of Energy and Mines, and the U.S. Geological Survey, and is designed for both scientific and practical purposes. It was prepared in two stages. First, separate maps and map explanations were prepared by the compilers. Second, the maps were combined, integrated, and supplemented by the editor. Map unit symbols were revised to a uniform system of classification and the map unit descriptions were prepared by the editor from information received from the compilers and from additional sources listed under Sources of Information. Diagrams accompanying the map were prepared by the editor. For scientific purposes, the map differentiates Quaternary surficial deposits on the basis of lithology or composition, texture or particle size, structure, genesis, stratigraphic relationships, engineering geologic properties, and relative age, as shown on the correlation diagram and

  7. Enantioselective catalytic syntheses of alpha-branched chiral amines

    DEFF Research Database (Denmark)

    Brase, S.; Baumann, T.; Dahmen, S.

    2007-01-01

    Chiral amines play a pivotal role in fine chemical and natural product syntheses and the design of novel materials.......Chiral amines play a pivotal role in fine chemical and natural product syntheses and the design of novel materials....

  8. Chiral pyrrolidinium salts derived from menthol as precursor – synthesis and properties

    Directory of Open Access Journals (Sweden)

    Janus Ewa

    2017-09-01

    Full Text Available Six new chiral pyrolidinium salts with chiral substituent at quaternary nitrogen atom were synthesized with high overall yields from (--menthol as cheap chiral precursor and were identified by NMR and HRMS spectroscopy. It was shown that anion type had the effect on chemical shift of protons adjacent to quaternary nitrogen atom and physical properties of these salts. Salts with NTf2 or NPf2 were in a liquid state at room temperature and characterized with the highest thermal stability among others. Furthermore, chiral ionic liquid with NTf2 anion was used as solvent in Diels-Alder reaction and gave higher yield and stereoselectivity than in ionic liquids with achiral cations. Synthesized chiral salts have the potential as chiral solvents in synthesis and auxiliaries in analytical methods to improve chiral recognition.

  9. Cyclohexanecarbonitriles: Assigning Configurations at Quaternary Centers From 13C NMR CN Chemical Shifts.1

    Science.gov (United States)

    Wei, Guoqing

    2009-01-01

    13C NMR chemical shifts of the nitrile carbon in cyclohexanecarbonitriles directly correlate with the configuration of the quaternary, nitrile-bearing stereocenter. Comparing 13C NMR chemical shifts for over 200 cyclohexanecarbonitriles reveals that equatorially oriented nitriles resonate 3.3 ppm downfield, on average, from their axial counterparts. Pairs of axial/equatorial diastereomers varying only at the nitrile-bearing carbon consistently exhibit downfield shifts of δ 0.4–7.2 for the equatorial nitrile carbon, even in angularly substituted decalins and hydrindanes. PMID:19348434

  10. Some aspects on the variations in depositional flux of excess Thorium-230 in the central Indian basin during Late Quaternary

    Digital Repository Service at National Institute of Oceanography (India)

    Sukumaran, N.P.

    Examined in this paper is the tentative history of the depositional flux of @u230@@Th@dxs@@ (the unsupported fraction of @u230@@Th scavenged from the overlying water column), for the Late Quaternary period from a sediment core of the Central Indian...

  11. In vitro Anti-Leishmania Activity and Safety of Newly Synthesized ...

    African Journals Online (AJOL)

    International Pharmaceutical Abstract, Chemical Abstracts, Embase, Index Copernicus, EBSCO, African. Index Medicus, JournalSeek ... virus (HAV), serotonin 5-HT6 receptor antagonist ..... Structure-activity relationships based on the obtained ...

  12. Acute toxicity and gastroprotection studies with a newly synthesized steroid.

    Science.gov (United States)

    Ketuly, Kamal A; Hadi, A Hamid A; Golbabapour, Shahram; Hajrezaie, Maryam; Hassandarvish, Pouya; Ali, Hapipah Mohd; Abdul Majid, Nazia; Abdulla, Mahmood A

    2013-01-01

    Synthetic steroids, such as 9α-bromobeclomethasonedipropionate, have shown gastroprotective activity. For example, the potent glucocorticoid steroid, beclomethasone dipropionate, has been used for treatment of bowel ulcerations. The purpose of the present study was to evaluate the effect of a synthetic steroid, (20S)-22-acetoxymethyl-6β-methoxy-3α,5-dihydro-3'H-cyclopropa[3α,5]-5α-pregnane (AMDCP), on ethanol-induced gastric mucosa injuries in rats. Rats were divided into 8 groups. The negative control and ethanol control groups were administered Tween 20 (10%v/v) orally. The reference control group, 20 mg/kg omeprazole (10% Tween 20, 5 mL/kg), was administrated orally. The experimental groups received 1, 5, 10, 15 or 20 mg/kg of the AMDCP compound (10% Tween 20, 5 mL/kg). After 60 min, Tween 20 and absolute ethanol was given orally (5 mL/kg) to the negative control group and to the rest of the groups, and the rats were sacrificed an hour later. The acidity of gastric content, gastric wall mucus and areas of mucosal lesions were assessed. In addition, histology and immunohistochemistry of the gastric wall were assessed. Prostaglandin E2 (PGE2) and malondialdehyde (MDA) content were also measured. The ethanol control group exhibited severe mucosal lesion compared with the experimental groups with fewer mucosal lesions along with a reduction of edema and leukocyte infiltration. Immunohistochemical staining of Hsp70 and Bax proteins showed over-expression and under-expression, respectively, in the experimental groups. The experimental groups also exhibited high levels of PGE2 as well as a reduced amount of MDA. AMDCP decreased the acidity and lipid peroxidation and increased the levels of antioxidant enzymes. The current investigation evaluated the gastroprotective effects of AMDCP on ethanol-induced gastric mucosal lesions in rats. This study also suggests that AMDCP might be useful as a gastroprotective agent.

  13. Spectroelectrochemical and electrochromic behaviors of newly synthesized poly[3′-(2-aminopyrimidyl)-2,2′:5′,2″-terthiophene

    International Nuclear Information System (INIS)

    Kim, Dong-Min; Shim, Kyu-Bin; Son, Jung Ik; Reddy, Sanapalli S.; Shim, Yoon-Bo

    2013-01-01

    The functionalized conductive polymer precursor of the terthiophene derivative, 3′-(2-aminopyrimidyl)-2,2′:5′,2″-terthiophene (PATT) was firstly synthesized and confirmed with FT-IR, 1 H NMR, 13 C NMR, and mass spectroscopy. The electrochemical and electronic properties of polyPATT film are investigated and compared with that of poly(2,2′:5′,2″-terthiophene-3′-p-benzoic acid) (polyTTBA), which has an electron-accepting group. The cyclic voltammograms (CVs) recorded for electrochemically grown polyPATT reveal the redox peaks at +1.1/+0.96 V, and the conductivity increases monotonically as the applying potential goes to the positive direction (0.11 S cm −1 at +1.4 V). The spectroelectrochemical analysis of polyPATT reveals the absorption bands at 456, 825 and 643 nm corresponding to the π–π* transition, polaron, and bipolaron formations, respectively. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the polyPATT film bearing an electron donating group are to be 3.60 and 5.54 eV, respectively. The polyPATT film shows reversible multiple color transition within 0.6 s (from brownish-yellow (at 0.0 V) to blue (at +1.4 V)) when the potential switches between the reduced and oxidized states

  14. A paleoenvironmental study of subsurface Quaternary sediments at Wainuiomata, Wellington, New Zealand, and tectonic implications

    Energy Technology Data Exchange (ETDEWEB)

    Begg, J G; Mildenhall, D C; Lyon, G L; Stephenson, W R; Funnell, R H; Van Dissen, R J; Bannister, S; Brown, L J [Institute of Geological and Nuclear Sciences Ltd., Lower Hutt (New Zealand); Pillans, B; Harper, M A [Research School of Earth Sciences, Victoria University of Wellington, Wellington (New Zealand); Whitton, J [Manaaki Whenua - Landcare Research, Lower Hutt, (New Zealand)

    1994-12-31

    A stratigraphic drillhole (WS-1) sited on the floor of Wainuiomata Valley near Lower Hutt, revealed a 61.6 m thick Quaternary sequence overlying Torlesse Supergroup greywacke sandstone and argillite. The Quaternary sediments consist of three sequences separated by disconformities. The lower sequence, 10.7 m thick (61.6-50.9 m), consists of fluvial sediments of probable early Quaternary age. The middle sequence, about 48.3 m in thickness (50.9-c. 2.6 m), spans most of the Last Glaciation. Fluvial/overbnak (50.9-42.0 m), floodplain/swamp (42.9-34.5 m), and fluvial (34.5-31.3 m) sediments overlie the disconformity at 50.9 m. Conformably overlying these sediments are swamp and lacustrine deposits between 31.3 and 4.1 m. Diatoms and algal spores and coenobia show the existence of an extensive lake during much of this sequence, from 25.6 to 4.0 m. at the peak of its development, at a drillhole depth of c. 23 m, the lake was >10 m deep and had a high algal biomass. Kawakawa Tephra (22 600 yr b.p.) occurs near the top of the middle sequence at 4.1 m depth. The upper sequence, of Holocene-Recent age, is <2.6 m thick, including .06 m of fill. The existence of sediments of the lower sequence of at least Castlecliffian age (early Pleistocene) uncomformably overlying basement greywacke provides a minimum age for the K-surface in the area. The Last Glacial sediments show evidence of ponfing, which may be a result of one factor or a more of the following: ponding behind an aggradational terrace of the Wainuiomata River; landslide blockage of the Black Stream drainage near its confluence with Wainuiomata River; and tectonic deformation. Progressive tectonic deformation since the start of the Last Glaciation is considered the most likely dominant factor. This has resulted in the elevation of greywacke basement near the junction of Black Stream and Wainuiomata River. The nature of the deformation - faulting, tilting, and/or folding - has not been established. 38 refs,6 figs,2 tables.

  15. Newport-Inglewood-Carlsbad-Coronado Bank Fault System Nearshore Southern California: Testing models for Quaternary deformation

    Science.gov (United States)

    Bennett, J. T.; Sorlien, C. C.; Cormier, M.; Bauer, R. L.

    2011-12-01

    The San Andreas fault system is distributed across hundreds of kilometers in southern California. This transform system includes offshore faults along the shelf, slope and basin- comprising part of the Inner California Continental Borderland. Previously, offshore faults have been interpreted as being discontinuous and striking parallel to the coast between Long Beach and San Diego. Our recent work, based on several thousand kilometers of deep-penetration industry multi-channel seismic reflection data (MCS) as well as high resolution U.S. Geological Survey MCS, indicates that many of the offshore faults are more geometrically continuous than previously reported. Stratigraphic interpretations of MCS profiles included the ca. 1.8 Ma Top Lower Pico, which was correlated from wells located offshore Long Beach (Sorlien et. al. 2010). Based on this age constraint, four younger (Late) Quaternary unconformities are interpreted through the slope and basin. The right-lateral Newport-Inglewood fault continues offshore near Newport Beach. We map a single fault for 25 kilometers that continues to the southeast along the base of the slope. There, the Newport-Inglewood fault splits into the San Mateo-Carlsbad fault, which is mapped for 55 kilometers along the base of the slope to a sharp bend. This bend is the northern end of a right step-over of 10 kilometers to the Descanso fault and about 17 km to the Coronado Bank fault. We map these faults for 50 kilometers as they continue over the Mexican border. Both the San Mateo - Carlsbad with the Newport-Inglewood fault and the Coronado Bank with the Descanso fault are paired faults that form flower structures (positive and negative, respectively) in cross section. Preliminary kinematic models indicate ~1km of right-lateral slip since ~1.8 Ma at the north end of the step-over. We are modeling the slip on the southern segment to test our hypothesis for a kinematically continuous right-lateral fault system. We are correlating four

  16. A paleoenvironmental study of subsurface Quaternary sediments at Wainuiomata, Wellington, New Zealand, and tectonic implications

    International Nuclear Information System (INIS)

    Begg, J.G.; Mildenhall, D.C.; Lyon, G.L.; Stephenson, W.R.; Funnell, R.H.; Van Dissen, R.J.; Bannister, S.; Brown, L.J.; Pillans, B.; Harper, M.A.; Whitton, J.

    1993-01-01

    A stratigraphic drillhole (WS-1) sited on the floor of Wainuiomata Valley near Lower Hutt, revealed a 61.6 m thick Quaternary sequence overlying Torlesse Supergroup greywacke sandstone and argillite. The Quaternary sediments consist of three sequences separated by disconformities. The lower sequence, 10.7 m thick (61.6-50.9 m), consists of fluvial sediments of probable early Quaternary age. The middle sequence, about 48.3 m in thickness (50.9-c. 2.6 m), spans most of the Last Glaciation. Fluvial/overbnak (50.9-42.0 m), floodplain/swamp (42.9-34.5 m), and fluvial (34.5-31.3 m) sediments overlie the disconformity at 50.9 m. Conformably overlying these sediments are swamp and lacustrine deposits between 31.3 and 4.1 m. Diatoms and algal spores and coenobia show the existence of an extensive lake during much of this sequence, from 25.6 to 4.0 m. at the peak of its development, at a drillhole depth of c. 23 m, the lake was >10 m deep and had a high algal biomass. Kawakawa Tephra (22 600 yr b.p.) occurs near the top of the middle sequence at 4.1 m depth. The upper sequence, of Holocene-Recent age, is <2.6 m thick, including .06 m of fill. The existence of sediments of the lower sequence of at least Castlecliffian age (early Pleistocene) uncomformably overlying basement greywacke provides a minimum age for the K-surface in the area. The Last Glacial sediments show evidence of ponfing, which may be a result of one factor or a combination of the following: ponding behind an aggradational terrace of the Wainuiomata River; landslide blockage of the Black Stream drainage near its confluence with Wainuiomata River; and tectonic deformation. Progressive tectonic deformation since about the start of the Last Glaciation is considered the most likely dominant factor. This has resulted in the elevation of greywacke basement near the junction of Black Stream and Wainuiomata River. The nature of the deformation - faulting, tilting, and/or folding - has not been established. (authors

  17. Syntheses and modulations in the chromatin contents of histones H1/sup o/ and H1 during G1 and S phases in Chinese hamsters cells

    International Nuclear Information System (INIS)

    D'Anna, J.A.; Gurley, L.R.; Tobey, R.A.

    1982-01-01

    Flow cytometry, conventional autoradiography, and autoradiography employing high concentrations of high specific activity [ 3 H]thymidine indicate that (1) treatment of Chinese hamster ovary (line CHO) cells with butyrate truly blocks cells in G 1 and (2) cells blocked in G 1 by isoleucine deprivation remain blocked in G 1 when they are released into complete medium containing butyrate. Measurements of H1/sup o/ content relative to core histones and H1/sup o/:H1 ratios indicate that H1/sup o/ is enhanced somewhat in G 1 cells arrested by isoleucine deprivation; however, (1) treatment with butyrate greatly increases the H1/sup o/ content in G 1 -blocked cells, and (2) the enhancement is very sensitive to butyrate concentration. Measurements of relative histone contents in the isolated chromatin of synchronized cultures also suggest that the acid-soluble content of histone H1 (relative to core histones) becomes greatly depleted in the isolated chromatin when synchronized cells are blocked in early S phase by sequential use of isoleucine deprivation and hydroxyurea blockade. We also have measured [ 3 H]lysine incorporation, various protein ratios, and relative rates of deposition of newly synthesized H1/sup o/, H1, and H4 onto chromatin during G 1 and S in the absence of butyrate. The results suggest a dynamic picture of chromatin organization in which (1) newly synthesized histone H1/sup o/ binds to chromatin during traverse of G 1 and S phases and (2) histone H1 dissociates from (or becomes loosely bound to) chromatin during prolonged early S-phase block with hydroxyurea

  18. Aeon: Synthesizing Scheduling Algorithms from High-Level Models

    Science.gov (United States)

    Monette, Jean-Noël; Deville, Yves; van Hentenryck, Pascal

    This paper describes the aeon system whose aim is to synthesize scheduling algorithms from high-level models. A eon, which is entirely written in comet, receives as input a high-level model for a scheduling application which is then analyzed to generate a dedicated scheduling algorithm exploiting the structure of the model. A eon provides a variety of synthesizers for generating complete or heuristic algorithms. Moreover, synthesizers are compositional, making it possible to generate complex hybrid algorithms naturally. Preliminary experimental results indicate that this approach may be competitive with state-of-the-art search algorithms.

  19. The development of [18F]FDG synthesizer

    International Nuclear Information System (INIS)

    Hu, M. G.; Kim, S. W.; Lee, J. Y.; Yang, S. D.; Jun, G. S.

    2003-01-01

    The automatic system for [ 18 F]FDG production using for the diagnosis of cancer has been developed. This automation system was consisted of a synthesizer module, a PLC based controller and a PMU for graphic user interface. By this system, the radiochemical purity was over 98%, the production yield was over 30% after synthesize and elapsed time was 35 minute

  20. Synthesis and Characterization of Novel Quaternary Thioaluminogermanates

    KAUST Repository

    Al-Bloushi, Mohammed

    2013-01-01

    compounds of the type “M(AlS2)(GeS2)” (M = Na and K) are new metal-chalcogenides, synthesized by the classical solid state approach. The characterization of these compounds was carried out by Scanning Electron Microscopy (SEM), Energy Dispersive X