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Sample records for 3-aminobenzanthrone enhance formation

  1. Base-Displaced Intercalated Structure of the N-(2'-Deoxyguanosin-8-yl)-3-aminobenzanthrone DNA Adduct.

    Politica, Dustin A; Malik, Chanchal K; Basu, Ashis K; Stone, Michael P

    2015-12-21

    3-Nitrobenzanthrone (3-NBA), an environmental mutagen found in diesel exhaust and a suspected carcinogen, undergoes metabolic reduction followed by reaction with DNA to form aminobenzanthrone (ABA) adducts, with the major alkylation product being N-(2'-deoxyguanosin-8-yl)-3-aminobenzanthrone (C8-dG-ABA). Site-specific synthesis of the C8-dG-ABA adduct in the oligodeoxynucleotide 5'-d(GTGCXTGTTTGT)-3':5'-d(ACAAACACGCAC)-3'; X = C8-dG-ABA adduct, including codons 272-275 of the p53 gene, has allowed for investigation into the structural and thermodynamic properties of this adduct. The conformation of the C8-dG-ABA adduct was determined using NMR spectroscopy and was refined using molecular dynamics (MD) calculations restrained by experimentally determined interproton distance restraints obtained from NOE experiments. The refined structure revealed that the C8-dG-ABA adduct formed a base-displaced intercalated conformation. The adducted guanine was shifted into the syn conformation about the glycosidic bond. The 5'- and 3'-neighboring base pairs remained intact. While this facilitated π-stacking interactions between the ABA moiety and neighboring bases, the thermal melting temperature (Tm) of the adduct-containing duplex showed a decrease of 11 °C as compared to the corresponding unmodified oligodeoxynucleotide duplex. Overall, in this sequence, the base-displaced intercalated conformation of the C8-dG-ABA lesion bears similarity to structures of other arylamine C8-dG adducts. However, in this sequence, the base-displaced intercalated conformation for the C8-dG-ABA adduct differs from the conformation of the N(2)-dG-ABA adduct reported by de los Santos and co-workers, in which it is oriented in the minor groove toward the 5' end of the duplex, with the modified guanine remaining in the anti conformation about the glyosidic torsion angle, and the complementary base remaining within the duplex. The results are discussed in relationship to differences between the C8-d

  2. 3-Nitrobenzanthrone and 3-aminobenzanthrone induce DNA damage and cell signalling in Hepa1c1c7 cells

    Landvik, N.E. [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway); Arlt, V.M.; Nagy, E. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Brookes Lawley Building, Sutton, Surrey SM2 5NG (United Kingdom); Solhaug, A. [Section for Toxicology, Department of Feed and Food Safety, National Veterinary Institute Pb 750 Sentrum, N-0106 Oslo (Norway); Tekpli, X. [EA SeRAIC, Equipe labellisee Ligue contre le Cancer, IFR 140, Universite de Rennes 1, Rennes (France); Schmeiser, H.H. [Research Group Genetic Alteration in Carcinogenesis, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Refsnes, M. [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway); Phillips, D.H. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Brookes Lawley Building, Sutton, Surrey SM2 5NG (United Kingdom); Lagadic-Gossmann, D. [EA SeRAIC, Equipe labellisee Ligue contre le Cancer, IFR 140, Universite de Rennes 1, Rennes (France); Holme, J.A., E-mail: jorn.holme@fhi.no [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway)

    2010-02-03

    3-Nitrobenzanthrone (3-NBA) is a mutagenic and carcinogenic environmental pollutant found in diesel exhaust and urban air pollution. In the present work we have characterised the effects of 3-NBA and its metabolite 3-aminobenzanthrone (3-ABA) on cell death and cytokine release in mouse hepatoma Hepa1c1c7 cells. These effects were related to induced DNA damage and changes in cell signalling pathways. 3-NBA resulted in cell death and caused most DNA damage as judged by the amount of DNA adducts ({sup 32}P-postlabelling assay), single strand (ss)DNA breaks and oxidative DNA lesions (comet assay) detected. An increased phosphorylation of H2AX, chk1, chk2 and partly ATM was observed using flow cytometry and/or Western blotting. Both compounds increased phosphorylation of p53 and MAPKs (ERK, p38 and JNK). However, only 3-NBA caused an accumulation of p53 in the nucleus and a translocation of Bax to the mitochondria. The p53 inhibitor pifithrin-alpha inhibited 3-NBA-induced apoptosis, indicating that cell death was a result of the triggering of DNA signalling pathways. The highest phosphorylation of Akt and degradation of I{kappa}B-{alpha} (suggesting activation of NF-{kappa}B) were also seen after treatment with 3-NBA. In contrast 3-ABA increased IL-6 release, but caused little or no toxicity. Cytokine release was inhibited by PD98059 and curcumin, suggesting that ERK and NF-{kappa}B play a role in this process. In conclusion, 3-NBA seems to have a higher potency to induce DNA damage compatible with its cytotoxic effects, while 3-ABA seems to have a greater effect on the immune system.

  3. 3-Nitrobenzanthrone and 3-aminobenzanthrone induce DNA damage and cell signalling in Hepa1c1c7 cells

    3-Nitrobenzanthrone (3-NBA) is a mutagenic and carcinogenic environmental pollutant found in diesel exhaust and urban air pollution. In the present work we have characterised the effects of 3-NBA and its metabolite 3-aminobenzanthrone (3-ABA) on cell death and cytokine release in mouse hepatoma Hepa1c1c7 cells. These effects were related to induced DNA damage and changes in cell signalling pathways. 3-NBA resulted in cell death and caused most DNA damage as judged by the amount of DNA adducts (32P-postlabelling assay), single strand (ss)DNA breaks and oxidative DNA lesions (comet assay) detected. An increased phosphorylation of H2AX, chk1, chk2 and partly ATM was observed using flow cytometry and/or Western blotting. Both compounds increased phosphorylation of p53 and MAPKs (ERK, p38 and JNK). However, only 3-NBA caused an accumulation of p53 in the nucleus and a translocation of Bax to the mitochondria. The p53 inhibitor pifithrin-alpha inhibited 3-NBA-induced apoptosis, indicating that cell death was a result of the triggering of DNA signalling pathways. The highest phosphorylation of Akt and degradation of IκB-α (suggesting activation of NF-κB) were also seen after treatment with 3-NBA. In contrast 3-ABA increased IL-6 release, but caused little or no toxicity. Cytokine release was inhibited by PD98059 and curcumin, suggesting that ERK and NF-κB play a role in this process. In conclusion, 3-NBA seems to have a higher potency to induce DNA damage compatible with its cytotoxic effects, while 3-ABA seems to have a greater effect on the immune system.

  4. Chondroitin Sulfate Perlecan Enhances Collagen Fibril Formation

    Kvist, A. J.; Johnson, A. E.; Mörgelin, M.;

    2006-01-01

    disaccharides typical for chondroitin sulfate E. Indeed, purified glycosaminoglycans from perlecan-enriched fractions of cartilage extracts contain elevated levels of 4,6-disulfated chondroitin sulfate disaccharides and enhance collagen fibril formation. The effect on collagen assembly is proportional to the...... content of the 4,6-disulfated disaccharide in the different cartilage extracts, with growth plate cartilage glycosaminoglycan being the most efficient enhancer. These findings demonstrate a role for perlecan chondroitin sulfate side chains in cartilage extracellular matrix assembly and provide an...... collagen type II fibril assembly by perlecan-null chondrocytes. Cartilage perlecan is a heparin sulfate or a mixed heparan sulfate/chondroitin sulfate proteoglycan. The latter form binds collagen and accelerates fibril formation in vitro, with more defined fibril morphology and increased fibril diameters...

  5. A new method to enhance rhizosheath formation

    Ahmadi, katayoun; Zarebanadkouki, Mohsen; Kuzyakov, Yakov; Carminati, Andrea

    2016-04-01

    The rhizosheath is defined as the soil that adheres to the roots by help of root hairs and mucilage. Rhizosheath maintain the contact between roots and soil improving water and nutrient uptake. Here we introduce: (1) a technique to quantify the formation of rhizosheath around the roots, and (2) a method to enhance the formation of rhizosheath around the roots. Additionally, we measured the relation between rhizosheath thickness and the carbon content and enzyme activities in the rhizosphere. We grew lupine plants in aluminum containers (28×30×1 cm) filled with a sandy soil. When plants were two weeks-old and the soil had a water content of 30%, we stopped the irrigation and let the plants to uptake water to a soil water content of 4-5%. Thereafter, half of the plants (4 plants) were irrigated with water and the other half with water with an additive (international patent is pending). We repeated the drying and rewetting cycle three times. At the end of the third drying cycle, when plants were 40 days old and soil had a water content of 4-5%,the containers were opened and roots and their surrounding soils were gently collected. We used imaging to quantify the rhizosheath formation. The method consists of scanning the roots and the surrounding soil using the Winrhizo software. By image analysis we quantified the thickness of roots and their rhizosheath. The plants irrigated with the additive had 63% thicker rhizopsheath than plants irrigated with water. So, the additive enhanced gelation of mucilage exuded by the roots. Carbon content and enzyme activity in the collected rhizosheath showed that the rhizosheath of plants irrigated with the additive had higher carbon content and enzyme activity than the rhizopsheath of plants irrigated with water. The new method to increase rhizosheath has the great advantage that can be easily applied to the irrigation water to improve plant uptake of water and nutrients in semiarid and arid areas.

  6. An Approach to Formative Evaluation for Teacher Enhancement Programs.

    Ruiz-Primo, Maria Araceli; Shavelson, Richard J.; Baxter, Gail P.

    This paper presents one possible approach to the formative evaluation of a Teacher Enhancement Program (TEP). The approach was applied to a National Science Foundation TEP designed to enhance teachers' knowledge and use of performance assessment technology. The study demonstrates the applicability of the approach to formative evaluation and…

  7. Methanofullerene elongated nanostructure formation for enhanced organic solar cells

    Using transmission electron microscopy (TEM) and Z-contrast imaging we have demonstrated elongated nanostructure formation of fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) within an organic host through annealing. The annealing provides an enhanced mobility of the PCBM molecules and, with good initial dispersion, allows for the formation of exaggerated grain growth within the polymer host. We have assembled these nanostructures within the regioregular conjugated polymer poly(3-hexylthiophene) (P3HT). This PCBM elongated nanostructure formation maybe responsible for the very high efficiencies observed, at very low loadings of PCBM (1:0.6, polymer to PCBM), in annealed photovoltaics. Moreover, our high resolution TEM and electron energy loss spectroscopy studies clearly show that the PCBM crystals remain crystalline and are unaffected by the 200-keV electron beam

  8. Methanofullerene elongated nanostructure formation for enhanced organic solar cells

    Reyes-Reyes, M. [Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, San Luis Potosi (Mexico)], E-mail: reyesm@cactus.iico.uaslp.mx; Lopez-Sandoval, R. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216. San Luis Potosi (Mexico); Arenas-Alatorre, J. [Instituto de Fisica, UNAM, Apartado Postal 20-364, 01000, Mexico, D.F. (Mexico); Garibay-Alonso, R. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216. San Luis Potosi (Mexico); Carroll, D.L. [Center for Nanotechnology and Molecular Materials, Department of Physics. Wake Forest University, Winston-Salem NC 27109 (United States); Lastras-Martinez, A. [Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, San Luis Potosi (Mexico)

    2007-11-01

    Using transmission electron microscopy (TEM) and Z-contrast imaging we have demonstrated elongated nanostructure formation of fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) within an organic host through annealing. The annealing provides an enhanced mobility of the PCBM molecules and, with good initial dispersion, allows for the formation of exaggerated grain growth within the polymer host. We have assembled these nanostructures within the regioregular conjugated polymer poly(3-hexylthiophene) (P3HT). This PCBM elongated nanostructure formation maybe responsible for the very high efficiencies observed, at very low loadings of PCBM (1:0.6, polymer to PCBM), in annealed photovoltaics. Moreover, our high resolution TEM and electron energy loss spectroscopy studies clearly show that the PCBM crystals remain crystalline and are unaffected by the 200-keV electron beam.

  9. Enhanced habit formation in Gilles de la Tourette syndrome.

    Delorme, Cécile; Salvador, Alexandre; Valabrègue, Romain; Roze, Emmanuel; Palminteri, Stefano; Vidailhet, Marie; de Wit, Sanne; Robbins, Trevor; Hartmann, Andreas; Worbe, Yulia

    2016-02-01

    SEE SINGER DOI101093/AWV378 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE:  Tics are sometimes described as voluntary movements performed in an automatic or habitual way. Here, we addressed the question of balance between goal-directed and habitual behavioural control in Gilles de la Tourette syndrome and formally tested the hypothesis of enhanced habit formation in these patients. To this aim, we administered a three-stage instrumental learning paradigm to 17 unmedicated and 17 antipsychotic-medicated patients with Gilles de la Tourette syndrome and matched controls. In the first stage of the task, participants learned stimulus-response-outcome associations. The subsequent outcome devaluation and 'slip-of-action' tests allowed evaluation of the participants' capacity to flexibly adjust their behaviour to changes in action outcome value. In this task, unmedicated patients relied predominantly on habitual, outcome-insensitive behavioural control. Moreover, in these patients, the engagement in habitual responses correlated with more severe tics. Medicated patients performed at an intermediate level between unmedicated patients and controls. Using diffusion tensor imaging on a subset of patients, we also addressed whether the engagement in habitual responding was related to structural connectivity within cortico-striatal networks. We showed that engagement in habitual behaviour in patients with Gilles de la Tourette syndrome correlated with greater structural connectivity within the right motor cortico-striatal network. In unmedicated patients, stronger structural connectivity of the supplementary motor cortex with the sensorimotor putamen predicted more severe tics. Overall, our results indicate enhanced habit formation in unmedicated patients with Gilles de la Tourette syndrome. Aberrant reinforcement signals to the sensorimotor striatum may be fundamental for the formation of stimulus-response associations and may contribute to the habitual behaviour and tics of

  10. Teacher Learning of Technology-Enhanced Formative Assessment

    Beatty, Ian D; Leonard, William J; Gerace, William J; Cyr, Karen St; Lee, Hyunju; Harris, Robby

    2008-01-01

    Technology-Enhanced Formative Assessment (TEFA) is a pedagogy for teaching with classroom response technology. Teacher Learning of TEFA is a five-year research project studying teacher change, in the context of an intensive professional development program designed to help science and mathematics teachers learn TEFA. First, we provide an overview of the project's participating teachers, its intervention (consisting of the technology, the pedagogy, and the professional development program), and its research design. Then, we present narratives describing the unfolding change process experienced by four teachers. Afterward, we present some preliminary findings of the research, describe a "model for the co-evolution of teacher and pedagogy" that we are developing, and identify general implications for professional development.

  11. Formation of Enhanced Uniform Chiral Fields in Symmetric Dimer Nanostructures

    Tian, Xiaorui; Sun, Mengtao

    2015-01-01

    Chiral fields with large optical chirality are very important in chiral molecules analysis, sensing and other measurements. Plasmonic nanostructures have been proposed to realize such super chiral fields for enhancing weak chiral signals. However, most of them cannot provide uniform chiral near-fields close to the structures, which makes these nanostructures not so efficient for applications. Plasmonic helical nanostructures and blocked squares have been proved to provide uniform chiral near-fields, but structure fabrication is a challenge. In this paper, we show that very simple plasmonic dimer structures can provide uniform chiral fields in the gaps with large enhancement of both near electric fields and chiral fields under linearly polarized light illumination with polarization off the dimer axis at dipole resonance. 30 times of volume averaged chiral field enhancement is gotten in the whole gap. Chiral fields with opposite handedness can be obtained simply by changing the polarization to the other side of...

  12. Linked supramolecular building blocks for enhanced cluster formation

    McLellan, Ross; Palacios, Maria A.; Beavers, Christine M.;

    2015-01-01

    (Figure Presented). Methylene-bridged calix[4]arenes have emerged as extremely versatile ligand supports in the formation of new polymetallic clusters possessing fascinating magnetic properties. Metal ion binding rules established for this building block allow one to partially rationalise the com...

  13. Enhancing the Reduction Potential of Quinones via Complex Formation.

    Nepal, Binod; Scheiner, Steve

    2016-05-20

    Quantum calculations are used to study the manner in which quinones interact with proton-donating molecules. For neutral donors, a stacked geometry is favored over a H-bond structure. The former is stabilized by charge transfers from the N or O lone pairs to the quinone's π* orbitals. Following the addition of an electron to the quinone, the radical anion forms strong H-bonded complexes with the various donors. The presence of the donor enhances the electron affinity of the quinone. This enhancement is on the order of 15 kcal/mol for neutral donors, but up to as much as 85 kcal/mol for a cationic donor. The increase in electron affinity is larger for electron-rich quinones than for their electron-deficient counterparts, containing halogen substituents. Similar trends are in evidence when the systems are immersed in aqueous solvent. PMID:27135719

  14. Formative Assessment Structures to Enhance Student Learning Despite Resource Limitiations

    Crean, Maire; Prunty, Catherine

    2011-01-01

    Higher Education student numbers are rising globally and yet teacher numbers are being reduced - all because of economic constraints and external criticisms. Despite these limitations, which all educators face today, the quality of teaching and depth of learning requires to be maintained. The impressive pace and rising numbers of educators who research and test methodologies which are developed and then shared to enhance teaching and learning is to be applauded. The study outlined in this art...

  15. Formation of Enhanced Uniform Chiral Fields in Symmetric Dimer Nanostructures.

    Tian, Xiaorui; Fang, Yurui; Sun, Mengtao

    2015-01-01

    Chiral fields with large optical chirality are very important in chiral molecules analysis, sensing and other measurements. Plasmonic nanostructures have been proposed to realize such super chiral fields for enhancing weak chiral signals. However, most of them cannot provide uniform chiral near-fields close to the structures, which makes these nanostructures not so efficient for applications. Plasmonic helical nanostructures and blocked squares have been proved to provide uniform chiral near-fields, but structure fabrication is a challenge. In this paper, we show that very simple plasmonic dimer structures can provide uniform chiral fields in the gaps with large enhancement of both near electric fields and chiral fields under linearly polarized light illumination with polarization off the dimer axis at dipole resonance. An analytical dipole model is utilized to explain this behavior theoretically. 30 times of volume averaged chiral field enhancement is gotten in the whole gap. Chiral fields with opposite handedness can be obtained simply by changing the polarization to the other side of the dimer axis. It is especially useful in Raman optical activity measurement and chiral sensing of small quantity of chiral molecule. PMID:26621558

  16. Heat stress enhances LTM formation in Lymnaea: role of HSPs and DNA methylation.

    Sunada, Hiroshi; Riaz, Hamza; de Freitas, Emily; Lukowiak, Kai; Swinton, Cayley; Swinton, Erin; Protheroe, Amy; Shymansky, Tamila; Komatsuzaki, Yoshimasa; Lukowiak, Ken

    2016-05-01

    Environmentally relevant stressors alter the memory-forming process in Lymnaea following operant conditioning of aerial respiration. One such stressor is heat. Previously, we found that following a 1 h heat shock, long-term memory (LTM) formation was enhanced. We also had shown that the heat stressor activates at least two heat shock proteins (HSPs): HSP40 and HSP70. Here, we tested two hypotheses: (1) the production of HSPs is necessary for enhanced LTM formation; and (2) blocking DNA methylation prevents the heat stressor-induced enhancement of LTM formation. We show here that the enhancing effect of the heat stressor on LTM formation occurs even if snails experienced the stressor 3 days previously. We further show that a flavonoid, quercetin, which inhibits HSP activation, blocks the enhancing effect of the heat stressor on LTM formation. Finally, we show that injection of a DNA methylation blocker, 5-AZA, before snails experience the heat stressor prevents enhancement of memory formation. PMID:27208033

  17. Technology-Enhanced Formative Assessment of Plant Identification

    Conejo, Ricardo; Garcia-Viñas, Juan Ignacio; Gastón, Aitor; Barros, Beatriz

    2016-04-01

    Developing plant identification skills is an important part of the curriculum of any botany course in higher education. Frequent practice with dried and fresh plants is necessary to recognize the diversity of forms, states, and details that a species can present. We have developed a web-based assessment system for mobile devices that is able to pose appropriate questions according to the location of the student. A student's location can be obtained using the device position or by scanning a QR code attached to a dried plant sheet in a herbarium or to a fresh plant in an arboretum. The assessment questions are complemented with elaborated feedback that, according to the students' responses, provides indications of possible mistakes and correct answers. Three experiments were designed to measure the effectiveness of the formative assessment using dried and fresh plants. Three questionnaires were used to evaluate the system performance from the students' perspective. The results clearly indicate that formative assessment is objectively effective compared to traditional methods and that the students' attitudes towards the system were very positive.

  18. Enhancement of laser induced Au nanoparticle formation by femtosecond pulse shaping

    Ferreira, P. H. D.; Silva, D. L.; Siqueira, J. P.; Balogh, D. T.; Canuto, S.; Misoguti, L.; Mendonca, C. R.

    2013-07-01

    We report the control of Au nanoparticle (NP) formation by using shaped 30 fs pulses, in a solution containing HAuCl4 and chitosan. By using a sinusoidal spectral phase, a periodic train of pulses is generated. When the period of the pulse train matches certain Raman resonances of chitosan, the reducing agent of the process, an enhancement of the Au NP formation is observed. Theoretical quantum chemical calculations indicate that the outer groups of the chitosan are mostly influenced by low Raman frequencies, which is in reasonably agreement with the experimental data and indicates an enhancement in the Au NP formation as the pulse train period increases (low frequency).

  19. Organic aerosol formation photo-enhanced by the formation of secondary photosensitizers in aerosols.

    Aregahegn, Kifle Z; Nozière, Barbara; George, Christian

    2013-01-01

    Secondary organic aerosols (SOA), which are produced by the transformations of volatile organic compounds in the atmosphere, play a central role in air quality, public health, visibility and climate, but their formation and aging remain poorly characterized. This study evidences a new mechanism for SOA formation based on photosensitized particulate-phase chemistry. Experiments were performed with a horizontal aerosol flow reactor where the diameter growth of the particles was determined as a function of various parameters. In the absence of gas-phase oxidant, experiments in which ammonium sulfate seeds containing glyoxal were exposed to gas-phase limonene and UV light exhibited a photo-induced SOA growth. Further experiments showed that this growth was due to traces of imidazole-2-carboxaldehyde (IC) in the seeds, a condensation product of glyoxal acting as an efficient photosensitizer. Over a 19 min irradiation time, 50 nm seed particles containing this compound were observed to grow between 3.5 and 30 +/- 3% in the presence of either limonene, isoprene, alpha-pinene, beta-pinene, or toluene in concentrations between 1.8 and 352 ppmv. The other condensation products of glyoxal, imidazole (IM) and 2,2-bi1H-imidazole (BI), also acted as photosensitizer but with much less efficiency under the same conditions. In the atmosphere, glyoxal and potentially other gas precursors would thus produce efficient photosensitizers in aerosol and autophotocatalyze SOA growth. PMID:24601000

  20. Enhancement of plaque formation and cell fusion of an enteropathogenic coronavirus by trypsin treatment.

    Storz, J.; Rott, R; Kaluza, G.

    1981-01-01

    Plaque formation, replication, and related cytopathic functions of the enteropathogenic bovine coronavirus strain L9 in bovine fetal thyroid (BFTy) and bovine fetal brain (BFB) cells were investigated in the presence and absence of trypsin. Plaque formation was enhanced in both cell types. Plaques reached a size with an average diameter of 5 mm within 4 days with trypsin in the overlay, whereas their diameter remained less than 1 mm at this time after plating without trypsin in the overlay. F...

  1. Enhancement of cold ground state Rb2 molecule formation by a wave shape resonance

    In this paper, we measured the temperature dependence of the Rb2 molecule formation rate constant in a MOT. We observed that the production of cold Rb2 via photoassociation in a magneto-optical trap can be enhanced by varying the temperature of the atomic sample using a molasses phase. Our results indicate that molecule production can be enhanced due to a wave shape resonance by a factor of six, and that the formed molecules are colder than the initial atoms.

  2. Forskolin enhances in vivo bone formation by human mesenchymal stromal cells

    Doorn, J.; Siddappa, R.; Blitterswijk, van C.A.; Boer, de J.

    2012-01-01

    Activation of the protein kinase A (PKA) pathway with dibutyryl cyclic adenosine monophosphate (db-cAMP) was recently shown to enhance osteogenic differentiation of human mesenchymal stromal cells (hMSCs) in vitro and bone formation in vivo. The major drawback of this compound is its inhibitory effe

  3. Xylella fastidiosa Extracellular Genomic DNA May Play a Role For Enhancing Biofilm Formation In Vitro

    Xylella fastidiosa (Xf) produces extracellular DNA in PD3 liquid medium. This extracellular DNA may play a role in enhancing biofilm formation, a factor that is required by Xf to establish infection in host plants. Amounts of extracellular DNA generated by Xf in vitro were positively correlated with...

  4. Cold oceans enhance terrestrial new-particle formation in near-coastal forests

    T. Suni

    2009-06-01

    Full Text Available The world's forests produce atmospheric aerosol by emitting volatile organic compounds (VOC which, after being oxidized in the atmosphere, readily condense on the omnipresent nanometer-sized nuclei and grow them to climatically relevant sizes. The cooling effect of aerosols is the greatest uncertainty in current climate models and estimates of radiative forcing. Therefore, identifying the environmental factors influencing the biogenic formation of aerosols is crucial. We show that, in addition to local meteorological factors in the forest, the magnitude of evaporation from oceans hundreds of kilometers upwind can effectively suppress or enhance new-particle formation. Our findings indicate that, unlike warm waters, the cold polar oceans provide excellent clean and dry background air that enhances aerosol formation above near-coastal forests in Fennoscandia and South-East Australia.

  5. Enhanced sulfate formation by nitrogen dioxide: Implications from in situ observations at the SORPES station

    Xie, Yuning; Ding, Aijun; Nie, Wei; Mao, Huiting; Qi, Ximeng; Huang, Xin; Xu, Zheng; Kerminen, Veli-Matti; Petäjä, Tuukka; Chi, Xuguang; Virkkula, Aki; Boy, Michael; Xue, Likun; Guo, Jia; Sun, Jianning; Yang, Xiuqun; Kulmala, Markku; Fu, Congbin

    2015-12-01

    Investigating sulfate formation processes is important not only for air pollution control but also for understanding the climate system. Although the mechanisms of secondary sulfate production have been widely studied, in situ observational evidence implicating an important role of NO2 in SO2 oxidation in the real atmosphere has been rare. In this study, we report two unique cases, from an intensive campaign conducted at the Station for Observing Regional Processes of the Earth System (SORPES) in East China, showing distinctly different mechanisms of sulfate formation by NO2 and related nitrogen chemistry. The first case occurred in an episode of mineral dust mixed with anthropogenic pollutants and especially high concentrations of NOx. It reveals that NO2 played an important role, not only in surface catalytic reactions of SO2 but also in dust-induced photochemical heterogeneous reactions of NO2, which produced additional sources of OH radicals to promote new particle formation and growth. The second case was caused by aqueous oxidation of S(IV) by NO2 under foggy/cloudy conditions with high NH3 concentration. As a by-product, the formed nitrite enhanced HONO formation and further promoted the gas-phase formation of sulfate in the downwind area. This study highlights the effect of NOx in enhancing the atmospheric oxidizing capacity and indicates a potentially very important impact of increasing NOx on particulate pollution formation and regional climate change in East Asia.

  6. Significant Enhancement of H2 Formation in Disk Galaxies under Strong Ram Pressure

    Henderson, Benjamin; Bekki, Kenji

    2016-05-01

    We show for the first time that H2 formation on dust grains can be enhanced in disk galaxies under strong ram pressure (RP). We numerically investigate how the time evolution of H i and H2 components in disk galaxies orbiting a group/cluster of galaxies can be influenced by the hydrodynamical interaction between the gaseous components of the galaxies and the hot intracluster medium. We find that compression of H i caused by RP increases H2 formation in disk galaxies before RP rapidly strips H i, cutting off the fuel supply and causing a drop in H2 density. We also find that the level of this H2 formation enhancement in a disk galaxy under RP depends on the mass of its host cluster dark matter halo, the initial positions and velocities of the disk galaxy, and the disk inclination angle with respect to the orbital plane. We demonstrate that dust growth is a key factor in the evolution of the H i and H2 mass in disk galaxies under strong RP. We discuss how the correlation between H2 fractions and surface gas densities of disk galaxies evolves with time in the galaxies under RP. We also discuss whether galaxy-wide star formation rates (SFRs) in cluster disk galaxies can be enhanced by RP if the SFRs depend on H2 densities.

  7. Depth profiles for hydrogen-enhanced thermal donor formation in silicon: Spreading resistance probe measurements

    Hydrogen enhancement of formation rates for oxygen-related thermal donors in Si has been investigated for dependence on: the source of hydrogen, hydrogen isotope, and exposure time and temperature. Hydrogen injection efficiency is an important variable and depth profiles are dependent upon the surface preparation of samples exposed in an electron cyclotron resonance plasma where ion energies are ≤35 eV. Formation rates up to 2 x 1016 cm-3 at 400 C have been observed. A sublinear dependence of the donor formation rate on beam current under 50 keV ion implantation is interpreted as a competition between oxygen-hydrogen and hydrogen-hydrogen interactions. Dependence on isotope mass and on exposure time in the plasma indicates hydrogen is the diffusing species that determines the penetration depth for the enhanced donor formation. Peculiar box-like depth profiles and high formation rates near the advancing front produced in RF plasma exposures are suggestive of hydrogen accumulation near the advancing front. The temperature dependence for the penetration depth gives in activation energy of 1.5 ± 0.2 eV. This energy is attributed to trap-limited diffusion wherein hydrogen lowers the energy barrier for the oxygen motion necessary to form thermal donors

  8. Enhancing the formation and shear resistance of nitrifying biofilms on membranes by surface modification

    Lackner, Susanne; Holmberg, Maria; Terada, Akihiko; Kingshott, P.; Smets, Barth F.

    2009-01-01

    Polypropylene (PP) membranes and polyethylene (PE) surfaces were modified to enhance formation and shear resistance of nitrifying biofilms for wastewater treatment applications. A combination of plasma polymerization and wet chemistry was employed to ultimately introduce poly(ethyleneglycol) (PEG...... structure might be possible explanations of the superiority of the -PEG-NH2 modification. The success of the-PEG-NH2 modification was independent of the original surface and might, therefore, be used in wastewater treatment bioreactors to improve reactor performance by making biofilm formation more stable...

  9. Enhancement in Secondary Organic Aerosol Formation in the Presence of Preexisting Organic Particle.

    Ye, Jianhuai; Gordon, Catherine A; Chan, Arthur W H

    2016-04-01

    Atmospheric models of secondary organic aerosol (SOA) typically assume organic species form a well-mixed phase. As a result, partitioning of semivolatile oxidation products into the particle phase to form SOA is thought to be enhanced by preexisting organic particles. In this work, the physicochemical properties that govern such enhancement in SOA yield were examined. SOA yields from α-pinene ozonolysis were measured in the presence of a variety of organic seeds which were chosen based on polarity and phase state at room temperature. Yield enhancement was only observed with seeds of medium polarities (tetraethylene glycol and citric acid). Solid hexadecanol seed was observed to enhance SOA yields only in chamber experiments with longer mixing time scales, suggesting that the mixing process for SOA and hexadecanol may be kinetically limited at shorter time scales. Our observations indicate that, in addition to kinetic limitations, intermolecular interactions also play a significant role in determining SOA yields. Here we propose for the first time to use the Hansen solubility framework to determine aerosol miscibility and predict SOA yield enhancement. These results highlight that current models may overestimate SOA formation, and parametrization of intermolecular forces is needed for accurate predictions of SOA formation. PMID:26963686

  10. Gauging Teachers' Needs with Regard to Technology- Enhanced Formative Assessment (TEFA) of 21st Century Skills in the Classroom

    Rusman, Ellen; Martínez-Monés, Alejandra; Boon, Jo; Rodríguez-Triana, María Jesús; Villagrá-Sobrino, Sara

    2014-01-01

    Several trends in society have led to a request towards schools to integrate 21st Century Skills and technology enhanced formative assessment (TEFA) in their curricula. Although there are frameworks defined at an international level, implementation of technology enhanced formative assessment of 21st

  11. Enhanced formation of Ge nanocrystals in Ge : SiO2 layers by swift heavy ions

    In this paper we report the ability of swift heavy Xe ions with an energy of 480 MeV and a fluence of 1012 cm-2 to enhance the formation of Ge nanocrystals within SiO2 layers with variable Ge contents. These Ge-SiO2 films were fabricated by the co-sputtering of Ge and quartz sources which followed various annealing procedures. In particular, we found that the irradiation of the Ge : SiO2 films with subsequent annealing at 500 °C leads to the formation of a high concentration of nanocrystals (NCs) with a size of 2-5 nm, whereas without irradiation only amorphous inclusions were observed. This effect, as evidenced by Raman spectra, is enhanced by pre-irradiation at 550 °C and post-irradiation annealing at 600 °C, which also leads to the observation of room temperature visible photoluminescence. (paper)

  12. Environmental Chamber Study of Atmospheric Chemistry and Secondary Organic Aerosol Formation Using Cavity Enhanced Absorption Spectroscopy

    Liu, Yingdi

    2011-01-01

    Air pollution and global climate change are important environmental issues that affect our society. Deeper understanding of atmospheric chemistry is required to understand these problems and to develop effective control strategies. Environmental chambers have been used for the past few decades to study atmospheric chemistry and investigate processes leading to secondary pollutant formation. This thesis work provides two different high sensitivity real time cavity enhance absorption spectrosco...

  13. Enhanced disinfection by-product formation due to nanoparticles in wastewater treatment plant effluents

    Metch, Jacob W.; Ma, Yanjun; Pruden, Amy; Vikesland, Peter J.

    2015-01-01

    Nanoparticles (NPs) are increasingly being incorporated into consumer products and are being used for industrial applications in ways that will lead to their environmental dissemination via wastewater treatment plants (WWTPs). Many NPs possess catalytic properties that could potentially enhance undesired chemical reactions such as the formation of disinfection by-products during disinfection of wastewater effluent. In this effort, silver (AgNPs), titanium dioxide (TiO2), ceria (CeO2), and nan...

  14. Formation of Triblock Copolymers via a Tandem Enhanced Spin Capturing-Nitroxide-Mediated Polymerization Reaction Sequence

    Junkers, Thomas; Zang, Lin; Wong, Edgar H. H.; Dingenouts, Nico; Barner-Kowollik, Christopher

    2011-01-01

    The preparation of ABA-type block copolymers via tandem enhanced spin capturing polymerization (ESCP) and nitroxide-mediated polymerization (NMP) processes is explored in-depth. Midchain alkoxyamine functional polystyrenes (M(n) = 6200, 12,500 and 19,900 g mol(-1)) were chain extended with styrene as well as tert-butyl acrylate at elevated temperature NMP conditions (T = 110 degrees C) generating a tandem ESCP-NMP sequence. Although the chain extensions and thus the block copolymer formation ...

  15. Enhanced acoustic cavitation following laser-induced bubble formation : long-term memory effect

    Yavaṣ, Oğuz; Leiderer, Paul; Park, Hee K.; Grigoropoulos, Costas P.; Poon, Chie C.; Tam, Andrew C.

    1994-01-01

    The enhancement of acoustic caviation at a liquid-solid interface following laser-induced bubble formation is studied. The experiment results indicate that metastable ultramicroscopic bubbles formed on the solid surface cause a long-term memory effect on acoustic cavitation. By performing a double-pulse experiment using two excimer lasers, the temporal decay of this memory effect is determined for two different liquids on a chromium surface. An explanation of the observed decay mode by a ...

  16. Formative research in clinical trial development: attitudes of patients with arthritis in enhancing prevention trials

    Taylor, Holly A.; Sugarman, Jeremy; Pisetsky, David S; Bathon, Joan

    2007-01-01

    In preparation for randomised controlled trials (RCTs) of disease‐modifying antirheumatic drugs in patients with early inflammatory arthritis (EIA), formative research was conducted to enhance the design of such trials. The objectives of this research were to (1) determine patients' educational needs as they relate to the necessary elements of informed consent; and (2) assess patients' interest in enrolling in a hypothetical prevention trial. In‐depth interviews were conducted with nine patie...

  17. Soybean Lectin Enhances Biofilm Formation by Bradyrhizobium japonicum in the Absence of Plants

    Julieta Pérez-Giménez

    2009-01-01

    Full Text Available Soybean lectin (SBL purified from soybean seeds by affinity chromatography strongly bound to Bradyrhizobium japonicum USDA 110 cell surface. This lectin enhanced biofilm formation by B. japonicum in a concentration-dependent manner. Presence of galactose during biofilm formation had different effects in the presence or absence of SBL. Biofilms were completely inhibited in the presence of both SBL and galactose, while in the absence of SBL, galactose was less inhibitory. SBL was very stable, since its agglutinating activity of B. japonicum cells as well as of human group A+ erythrocytes was resistant to preincubation for one week at 60°C. Hence, we propose that plant remnants might constitute a source of this lectin, which might remain active in soil and thus favor B. japonicum biofilm formation in the interval between soybean crop seasons.

  18. TOL Plasmid Carriage Enhances Biofilm Formation and Increases Extracellular DNA Content in Pseudomonas Putida KT2440

    Smets, Barth F.; D'Alvise, Paul; Yankelovich, T.;

    Adherent growth of Pseudomonas putida KT2440 with and without the TOL plasmid (pWWO) at the solid-liquid and air-liquid interface was examined. We compared biofilm formation on glass in flow cells, and assayed pellicle (air-liquid interface biofilm) formation in stagnant liquid cultures by confocal...... laser scanning microscopy. The TOL-carrying strains formed pellicles and thick biofilms, whereas the same strains without the plasmid displayed little adherent growth. Microscopy using fluorescent nucleic acid- specific stains (cytox orange, propidium iodide) revealed differences in production...... combined with specific cytostains; release of cytoplasmic material was assayed by a β-glucosidase assay. Enhanced cell lysis due to plasmid carriage was ruled out as the mechanism for eDNA release. We report, for the first time, that carriage of a conjugative plasmid leads to increased biofilm formation...

  19. Forskolin enhances in vivo bone formation by human mesenchymal stromal cells.

    Doorn, Joyce; Siddappa, Ramakrishnaiah; van Blitterswijk, Clemens A; de Boer, Jan

    2012-03-01

    Activation of the protein kinase A (PKA) pathway with dibutyryl cyclic adenosine monophosphate (db-cAMP) was recently shown to enhance osteogenic differentiation of human mesenchymal stromal cells (hMSCs) in vitro and bone formation in vivo. The major drawback of this compound is its inhibitory effect on proliferation of hMSCs. Therefore, we investigated whether fine-tuning of the dose and timing of PKA activation could enhance bone formation even further, with minimum effects on proliferation. To test this, we selected two different PKA activators (8-bromo-cAMP (8-br-cAMP) and forskolin) and compared their effects on proliferation and osteogenic differentiation with those of db-cAMP. We found that all three compounds induced alkaline phosphatase levels, bone-specific target genes, and secretion of insulin-like growth factor-1, although 8-br-cAMP induced adipogenic differentiation in long-term cultures and was thus considered unsuitable for further in vivo testing. All three compounds inhibited proliferation of hMSCs in a dose-dependent manner, with forskolin inhibiting proliferation most. The effect of forskolin on in vivo bone formation was tested by pretreating hMSCs before implantation, and we observed greater amounts of bone using forskolin than db-cAMP. Our data show forskolin to be a novel agent that can be used to increase bone formation and also suggests a role for PKA in the delicate balance between adipogenic and osteogenic differentiation. PMID:21942968

  20. Enhancement of nanovoid formation in annealed amorphous Al2O3 including W

    Nakamura, R.; Ishimaru, M.; Hirata, A.; Sato, K.; Tane, M.; Kimizuka, H.; Shudo, T.; Konno, T. J.; Nakajima, H.

    2011-09-01

    The effect of W on the nanovoid formation in annealed amorphous Al2O3 was studied by transmission electron microscopy and molecular dynamics simulations. A comparison of the void formation behavior in electron-beam deposited Al2O3 (without W) and resistance-heating deposited Al2O3 (with 10 at. % W) revealed that W enhances the formation and growth of nanovoids. An analysis of the pair distribution function (PDF) in both types of amorphous Al2O3 showed that the introduction of W into amorphous Al2O3 brings about a significant change in the amorphous structure. Furthermore, it was found by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) that sub-nm sized W clusters exist in as-deposited Al2O3 prepared by resistance-heating and then dissolve in the amorphous matrix with annealing. The combination of PDF analysis and HAADF-STEM observation provides evidence that the enhancement of void formation originates in the heterogeneous short-range atomic configurations induced by the addition of W.

  1. Significant enhancement of ${\\rm H_2}$ formation in disk galaxies under strong ram pressure

    Henderson, Benjamin

    2016-01-01

    We show, for the first time, that ${\\rm H_2}$ formation on dust grains can be enhanced in disk galaxies under strong ram-pressure (RP). We numerically investigate how the time evolution, of ${\\rm H}$ {\\sc i} and ${\\rm H_2}$ components in disk galaxies orbiting a group/cluster of galaxies, can be influenced by hydrodynamical interaction between the gaseous components of the galaxies and the hot intra-cluster medium (ICM). We find that compression of ${\\rm H}$ {\\sc i} caused by RP increases ${\\rm H_2}$ formation in disk galaxies, before RP rapidly strips ${\\rm H}$ {\\sc i}, cutting off the fuel supply and causing a drop in ${\\rm H_2}$ density. We also find that the level of this ${\\rm H_2}$ formation enhancement in a disk galaxy under RP depends on the mass of its host cluster dark matter (DM) halo, initial positions and velocities of the disk galaxy, and disk inclination angle with respect to the orbital plane. We demonstrate that dust growth is a key factor in the evolution of the ${\\rm H}$ {\\sc i} and ${\\rm H...

  2. The EP3 Agonist Sulprostone Enhances Platelet Adhesion But Not Thrombus Formation Under Flow Conditions.

    Pasterk, Lisa; Philipose, Sonia; Eller, Kathrin; Marsche, Gunther; Heinemann, Akos; Schuligoi, Rufina

    2015-01-01

    Platelets express the EP2, EP3 and EP4 receptors. Prostaglandin (PG) E2 has a biphasic effect on platelets. Low concentrations of PGE2 enhance platelet aggregation through the activation of the EP3 receptors, while at high concentrations it attenuates aggregation via the EP4 receptor. Consequently, EP3 receptor inhibition was shown to inhibit artherothrombosis, but had no influence on bleeding time in vivo. In this study, we investigated the role of the EP3 receptor in adhesion and thrombus formation under flow conditions in vitro. The EP3 agonist sulprostone caused an increase in the adhesion of washed platelets to fibrinogen as well as to collagen under low shear stress, an effect that was blocked by the EP3 antagonist L-798106. In contrast, when whole blood was perfused over collagen-coated surfaces, sulprostone did not enhance binding and thrombus formation of platelets on collagen; at high concentrations it even attenuated this response. We conclude that in more physiological models of thrombus formation, the role for EP3 receptors is limited, indirectly suggesting that the primary action of PGE2 in haemostasis might be an inhibitory one. PMID:26228833

  3. Formation and evolution of carbon-enhanced metal-poor stars

    Carbon-enhanced metal-poor (CEMP) stars play a key role in characterising the star formation history of the Galactic halo. In particular, the fraction of CEMP stars among extremely metalpoor stars (EMP stars, defined by [Fe/H] < -2.5) is useful information in constraining the stellar IMF in the early universe. In our previous work, it is proposed that the typical mass of EMP stars should be around 10 Msun at [Fe/H] < -2 under the assumption that all the CEMP stars belong to binary systems and originate from a mass transfer from the former AGB stars. In this paper, we explore the origin of CEMP stars without the enhancement of s-process element abundances (so called CEMP-no stars) that dominate the CEMP population at [Fe/H] < -3.5. The reason for the large CEMP-no fraction is currently an important issue to elucidate the star formation history in the early universe in terms of the chemical evolution of the Galaxy, the contribution of AGB stars to the CEMP populations, and the IMF of first stars and EMP stars. We will discuss the reason for the increasing CEMP-no fraction (or decreasing CEMP-s (CEMP stars with s-process element enhancement) fraction) with decreasing metallicity, using binary population synthesis based on the stellar evolution and nucleosynthesis of first stars and EMP stars, taking into account the possible effect of mass loss and the hot bottom burning at low metallicity. (author)

  4. The enhancement of biofilm formation in Group B streptococcal isolates at vaginal pH.

    Ho, Yueh-Ren; Li, Chien-Ming; Yu, Chen-Hsiang; Lin, Yuh-Jyh; Wu, Ching-Ming; Harn, I-Chen; Tang, Ming-Jer; Chen, Yi-Ting; Shen, Fang-Chi; Lu, Chien-Yi; Tsai, Tai-Chun; Wu, Jiunn-Jong

    2013-04-01

    Group B streptococcus (GBS) is a common asymptomatic colonizer in acidic vagina of pregnant women and can transmit to newborns, causing neonatal pneumonia and meningitis. Biofilm formation is often associated with bacterial colonization and pathogenesis. Little is known about GBS biofilm and the effect of environmental stimuli on their growth along with biofilm formation. The objective of this study was to investigate the survival and biofilm formation of GBS, isolated from pregnant women, in nutrient-limited medium under various pH conditions. Growth and survival experiments were determined by optical density and viable counts. Crystal violet staining, scanning electron microscopy, and atomic force microscopy (AFM) were used to analyze the capacity of biofilm production. Our results showed that GBS isolates proliferated with increasing pH with highest maximum specific growth rate (μmax) at pH 6.5, but survived at pH 4.5 for longer than 48 h. Biofilm formation of the 80 GBS isolates at pH 4.5 was significantly higher than at pH 7.0. This difference was confirmed by two other methods. The low elastic modulus obtained from samples at pH 4.5 by AFM revealed the softness of biofilm; in contrast, little or no biofilm was measured at pH 7.0. Under acidic pH, the capability of biofilm formation of serotypes III and V showed statistically significant difference from serotypes Ia and Ib. Our finding suggested that survival and enhanced biofilm formation at vaginal pH are potentially advantageous for GBS in colonizing vagina and increase the risk of vaginosis and neonatal infection. PMID:22797522

  5. Shelf-to-basin iron shuttling enhances vivianite formation in deep Baltic Sea sediments

    Reed, Daniel C.; Gustafsson, Bo G.; Slomp, Caroline P.

    2016-01-01

    Coastal hypoxia is a growing and persistent problem largely attributable to enhanced terrestrial nutrient (i.e., nitrogen and phosphorus) loading. Recent studies suggest phosphorus removal through burial of iron (II) phosphates, putatively vivianite, plays an important role in nutrient cycling in the Baltic Sea - the world's largest anthropogenic dead zone - yet the dynamics of iron (II) phosphate formation are poorly constrained. To address this, a reactive-transport model was used to reconstruct the diagenetic and depositional history of sediments in the Fårö basin, a deep anoxic and sulphidic region of the Baltic Sea where iron (II) phosphates have been observed. Simulations demonstrate that transport of iron from shelf sediments to deep basins enhances vivianite formation while sulphide concentrations are low, but that pyrite forms preferentially over vivianite when sulphate reduction intensifies due to elevated organic loading. Episodic reoxygenation events, associated with major inflows of oxic waters, encourage the retention of iron oxyhydroxides and iron-bound phosphorus in sediments, increasing vivianite precipitation as a result. Results suggest that artificial reoxygenation of the Baltic Sea bottom waters could sequester up to 3% of the annual external phosphorus loads as iron (II) phosphates, but this is negligible when compared to potential internal phosphorus loads due to dissolution of iron oxyhydroxides when low oxygen conditions prevail. Thus, enhancing vivianite formation through artificial reoxygenation of deep waters is not a viable engineering solution to eutrophication in the Baltic Sea. Finally, simulations suggest that regions with limited sulphate reduction and hypoxic intervals, such as eutrophic estuaries, could act as important phosphorus sinks by sequestering vivianite. This could potentially alleviate eutrophication in shelf and slope environments.

  6. Quantitative Modeling Of Formation Damage On The Reservoir During Microbial Enhanced Oil Recovery

    Nmegbu, Chukwuma Godwin Jacob

    2014-07-01

    Full Text Available Microbial enhanced oil recovery is an inexpensive, environmentally friendly method of oil recovery, utilizing the potentials of certain microbes to significantly influence oil productionwith wide range of oil recovery mechanisms including oil mobilization, reservoir re-pressurization, permeability alteration, mobility control and a range of other exploitable recovery techniques. This study presents an investigation on the degree of damage to the reservoir as a result of microbial injection. Results from this analysis shows that for a continuous microbial injection process, the pore area of the formation reduces equivalently due to microbial plugging and or as a result of biomass accumulation in the reservoir. The prevailing effects of formation damage (skin due to these microbes are also presented. Residual fluid flow rates and corresponding velocities were found to reduce in magnitude with deducing pore area after several days of injection.

  7. TOL plasmid carriage enhances biofilm formation and increases extracellular DNA content in Pseudomonas putida KT2440

    D'Alvise, Paul; Sjoholm, O.R.; Yankelevich, T.;

    2010-01-01

    Adherent growth of Pseudomonas putida KT2440 with and without the TOL plasmid (pWWO) at the solid-liquid and air-liquid interface was examined. We compared biofilm formation on glass in flow cells, and assayed pellicle (air-liquid interface biofilm) formation in stagnant liquid cultures by confocal...... laser scanning microscopy. The TOL-carrying strains formed pellicles and thick biofilms, whereas the same strains without the plasmid displayed little adherent growth. Microscopy using fluorescent nucleic acid-specific stains revealed differences in the production of extracellular polymeric substances......: TOL carriage leads to more extracellular DNA (eDNA) in pellicles and biofilms. Pellicles were dissolved by DNase I treatment. Enhanced cell lysis due to plasmid carriage was ruled out as the mechanism for eDNA release. We report, for the first time, that carriage of a conjugative plasmid leads to...

  8. Enhanced BMP signaling results in supernumerary tooth formation in USAG-1 deficient mouse

    Uterine sensitization associated gene-1 (USAG-1) is a BMP antagonist, and also modulates Wnt signaling. We previously reported that USAG-1 deficient mice have supernumerary teeth. The supernumerary maxillary incisor appears to form as a result of the successive development of the rudimentary upper incisor. USAG-1 abrogation rescued apoptotic elimination of odontogenic mesenchymal cells. We confirmed that BMPs were expressed in both the epithelium and mesenchyme of the rudimentary incisor at E14 and E15. BMP signaling in the rudimentary maxillary incisor, assessed by expressions of Msx1 and Dlx2 and the phosphorylation of Smad protein, was significantly enhanced. Wnt signaling as demonstrated by the nuclear localization of β-catenin was also up-regulated. Inhibition of BMP signaling rescues supernumerary tooth formation in E15 incisor explant culture. Based upon these results, we conclude that enhanced BMP signaling results in supernumerary teeth and BMP signaling was modulated by Wnt signaling in the USAG-1 deficient mouse model

  9. Formation Regularities of Plasmonic Silver Nanostructures on Porous Silicon for Effective Surface-Enhanced Raman Scattering.

    Bandarenka, Hanna V; Girel, Kseniya V; Bondarenko, Vitaly P; Khodasevich, Inna A; Panarin, Andrei Yu; Terekhov, Sergei N

    2016-12-01

    Plasmonic nanostructures demonstrating an activity in the surface-enhanced Raman scattering (SERS) spectroscopy have been fabricated by an immersion deposition of silver nanoparticles from silver salt solution on mesoporous silicon (meso-PS). The SERS signal intensity has been found to follow the periodical repacking of the silver nanoparticles, which grow according to the Volmer-Weber mechanism. The ratio of silver salt concentration and immersion time substantially manages the SERS intensity. It has been established that optimal conditions of nanostructured silver layers formation for a maximal Raman enhancement can be chosen taking into account a special parameter called effective time: a product of the silver salt concentration on the immersion deposition time. The detection limit for porphyrin molecules CuTMPyP4 adsorbed on the silvered PS has been evaluated as 10(-11) M. PMID:27209406

  10. Enhancement of bone formation in rabbits by recombinant human growth hormone

    We studied the effect of human recombinant growth hormone on diaphyseal bone in 40 adult rabbits. The diaphyseal periosteum of one femur in each animal was mechanically stimulated by a nylon cerclage band. The bands induced an increase in bone formation, bone mineral content, and maximum torque capacity of the diaphyseal bone at 1 and 2 months. Growth hormone enhanced the anabolic effect of the cerclage bands on bone metabolism, evidenced by a further increase in torsional strength of the femurs. (au) (32 refs.)

  11. Significant enhancement of ${\\rm H_2}$ formation in disk galaxies under strong ram pressure

    Henderson, Benjamin; Bekki, Kenji

    2016-01-01

    We show, for the first time, that ${\\rm H_2}$ formation on dust grains can be enhanced in disk galaxies under strong ram-pressure (RP). We numerically investigate how the time evolution, of ${\\rm H}$ {\\sc i} and ${\\rm H_2}$ components in disk galaxies orbiting a group/cluster of galaxies, can be influenced by hydrodynamical interaction between the gaseous components of the galaxies and the hot intra-cluster medium (ICM). We find that compression of ${\\rm H}$ {\\sc i} caused by RP increases ${\\...

  12. Apparatus and process to enhance the uniform formation of hollow glass microspheres

    Schumacher, Ray F

    2013-10-01

    A process and apparatus is provided for enhancing the formation of a uniform population of hollow glass microspheres. A burner head is used which directs incoming glass particles away from the cooler perimeter of the flame cone of the gas burner and distributes the glass particles in a uniform manner throughout the more evenly heated portions of the flame zone. As a result, as the glass particles are softened and expand by a released nucleating gas so as to form a hollow glass microsphere, the resulting hollow glass microspheres have a more uniform size and property distribution as a result of experiencing a more homogenous heat treatment process.

  13. STUDY ON INVITRO PERMEATION ENHANCEMENT OF KETOPROFEN BY FORMATION OF SOLID DISPERSION

    Saleem M.A

    2011-04-01

    Full Text Available Solid dispersions of ketoprofen were prepared by using different water soluble carriers like β-cyclodextrin, PEG 6000, polyvinyl pyrolidone and urea in appropriate concentration to enhance the transdermal flux. The prepared solid dispersions were characterized by IR spectroscopy & DSC suggested no interaction of drug with carriers. The solid dispersions were evaluated for solubility, Invitro dissolution and Invitro permeation through rat skin. The solubility of ketoprofen was enhanced 3-7 times in order of solid dispersion, ureaenhanced solubility and dissolution of ketoprofen in donor compartment. The highest flux was obtained with β-cyclodextrin (446.31mcg/cm2/h and PEG 6000 (432.22mcg/cm2/h. Hence the permeation flux of ketoprofen could be enhanced by formation of solid dispersion for effective topical preparations.

  14. Silica enhanced formation of hydroxyapatite nanocrystals in simulated body fluid (SBF) at 37 deg. C

    Sadjadi, M.S., E-mail: m.s.sadjad@gmail.com [Department of Chemistry, Sciences and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Ebrahimi, H.R. [Department of Chemistry, Sciences and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Meskinfam, M. [Department of Chemistry, Tonekabon Branch, Islamic Azad University, Tonekabon (Iran, Islamic Republic of); Zare, K. [Department of Chemistry, University of Shahid Beheshti, Eveen Tehran (Iran, Islamic Republic of)

    2011-10-17

    Highlights: {yields} We report on fast formation of hexagonal nanocrystals of calcium hydroxyapatite (HA) in silica-containing simulated body fluid solution at 37 deg. C. {yields} Bioactivity and biodegradability of TCP precursor have been confirmed by the dissolution of TCP and formation of a bone like layer of new HA nanoparticles outside of the precursor after 24 h soaking in SBF solution. {yields} Successive nucleation and formation of tiny hexagonal HA nanoplates and nanorods have been confirmed by TEM results after 24 h soaking of TCP in silica-containing BSF solution. - Abstract: The chemical modification of implant (prosthesis) surfaces is being investigated worldwide for improving the fixation of orthopaedic and dental implants. The main goal in this surface modification approach is to achieve a faster bone growth and chemical bonding of the implant to the newly generated and/or remodeled bone. In this work, we report fast formation of hexagonal nanocrystals of calcium hydroxyapatite (HA) in simulated body fluid (SBF, inorganic components of human blood plasma) solutions at 37 deg. C, using calcium phosphate (TCP) and sodium silicate as precursors. Characterization and chemical analysis of the synthesized powders were performed by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicated enhanced nucleation and formation of bone like layer of HA nanocrystals at the surface of TCP nanoparticles and occurrence of HA nanocrystals during 24 h soaking of TCP in SBF solution containing silica ions. The average size of a nanoparticle, using Scherrer formula, was found to be 18.2 nm.

  15. Silica enhanced formation of hydroxyapatite nanocrystals in simulated body fluid (SBF) at 37 deg. C

    Highlights: → We report on fast formation of hexagonal nanocrystals of calcium hydroxyapatite (HA) in silica-containing simulated body fluid solution at 37 deg. C. → Bioactivity and biodegradability of TCP precursor have been confirmed by the dissolution of TCP and formation of a bone like layer of new HA nanoparticles outside of the precursor after 24 h soaking in SBF solution. → Successive nucleation and formation of tiny hexagonal HA nanoplates and nanorods have been confirmed by TEM results after 24 h soaking of TCP in silica-containing BSF solution. - Abstract: The chemical modification of implant (prosthesis) surfaces is being investigated worldwide for improving the fixation of orthopaedic and dental implants. The main goal in this surface modification approach is to achieve a faster bone growth and chemical bonding of the implant to the newly generated and/or remodeled bone. In this work, we report fast formation of hexagonal nanocrystals of calcium hydroxyapatite (HA) in simulated body fluid (SBF, inorganic components of human blood plasma) solutions at 37 deg. C, using calcium phosphate (TCP) and sodium silicate as precursors. Characterization and chemical analysis of the synthesized powders were performed by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicated enhanced nucleation and formation of bone like layer of HA nanocrystals at the surface of TCP nanoparticles and occurrence of HA nanocrystals during 24 h soaking of TCP in SBF solution containing silica ions. The average size of a nanoparticle, using Scherrer formula, was found to be 18.2 nm.

  16. Oleic acid induces smooth muscle foam cell formation and enhances atherosclerotic lesion development via CD36

    Tang Bing

    2011-04-01

    Full Text Available Abstract Background Elevated plasma free fatty acid (FFA levels have been linked to the development of atherosclerosis. However, how FFA causes atherosclerosis has not been determined. Because fatty acid translocase (FAT/CD36 is responsible for the uptake of FFA, we hypothesized that the atherogenic effects of FFA may be mediated via CD36. Results We tested this hypothesis using cultured rat aortic smooth muscle cells (SMCs treated with oleic acid (OA. We found that OA induces lipid accumulation in SMCs in a dose dependent manner. Rat aortic SMCs treated for 48 hours with OA (250 μmol/L became foam cells based on morphological (Oil Red O staining and biochemical (5 times increase in cellular triglyceride criteria. Moreover, specific inhibition of CD36 by sulfo-N-succinimidyl oleate significantly attenuated OA induced lipid accumulation and foam cell formation. To confirm these results in vivo, we used ApoE-deficient mice fed with normal chow (NC, OA diet, NC plus lipolysis inhibitor acipimox or OA plus acipimox. OA-fed mice showed increased plasma FFA levels and enhanced atherosclerotic lesions in the aortic sinus compared to the NC group (both p 5 μm2 vs. OA plus acipimox: 2.60 ± 0.10 ×105 μm2, p p Conclusions These findings suggest that OA induces smooth muscle foam cell formation and enhances atherosclerotic lesions in part though CD36. Furthermore, these findings provide a novel model for the investigation of atherosclerosis.

  17. Studying Pellet Formation of a Filamentous Fungus Rhizopus oryzae to Enhance Organic Acid Production

    Liao, Wei; Liu, Yan; Chen, Shulin

    Using pelletized fungal biomass can effectively improve the fermentation performance for most of fugal strains. This article studied the effects of inoculum and medium compositions such as potato dextrose broth (PDB) as carbon source, soybean peptone, calcium carbonate, and metal ions on pellet formation of Rhizopus oryzae. It has been found that metal ions had significantly negative effects on pellet formation whereas soybean peptone had positive effects. In addition PDB and calcium carbonate were beneficial to R. oryzae for growing small smooth pellets during the culture. The study also demonstrated that an inoculum size of less than 1.5×109 spores/L had no significant influence on pellet formation. Thus, a new approach to form pellets has been developed using only PDB, soybean peptone, and calcium carbonate. Meanwhile, palletized fungal fermentation significantly enhanced organic acid production. Lactic acid concentration reached 65.0 g/L in 30 h using pelletized R. oryzae NRRL 395, and fumeric acid concentration reached 31.0 g/L in 96 h using pelletized R. oryzae ATCC 20344.

  18. Synthetic octacalcium phosphate-enhanced reparative dentine formation via induction of odontoblast differentiation.

    Wang, Xiaogu; Suzawa, Tetsuo; Miyauchi, Tomohiko; Zhao, Baohong; Yasuhara, Rika; Anada, Takahisa; Nakamura, Masanori; Suzuki, Osamu; Kamijo, Ryutaro

    2015-11-01

    Synthetic octacalcium phosphate (OCP) has been suggested to be a useful biomaterial for the regeneration of hard tissues, including bone. However, it remains unknown whether OCP induces dentine formation by dental pulp. We investigated biomineralization of dental pulp exposed to synthetic OCP in vitro and in vivo. When dental pulp was exposed directly to OCP, rapid formation of reparative dentine (RD) was induced and expression of dentine sialoprotein synthesis was observed in dental pulp adjacent to newly synthesized RD. OCP inhibited the proliferation of rat pulp cells and also promoted their odontoblastic differentiation in vitro, as alkaline phosphatase activity, mineralization of pulp cells and the expression level of dentine sialophosphoprotein were enhanced. Direct contact between OCP and pulp cells is required for OCP to exhibit its effects in vitro. The expression level of Runx2, a transcription factor whose downregulation is closely related to odontoblast differentiation, was downregulated in pulp cells cultured with OCP. Structural changes of OCP during culture were determined by Fourier transform infrared spectroscopy. OCP tended to be converted to carbonate hydroxyapatite after incubation with or without pulp cells, which may be analogous to biological apatite crystals. Taken together, our data suggest that synthetic OCP supports RD formation by dental pulp and downregulation of Runx2 may be involved in that stimulatory activity. Furthermore, OCP-apatite conversion is involved in this stimulatory capacity of OCP. PMID:23355511

  19. QHREDGS enhances tube formation, metabolism and survival of endothelial cells in collagen-chitosan hydrogels.

    Jason W Miklas

    Full Text Available Cell survival in complex, vascularized tissues, has been implicated as a major bottleneck in advancement of therapies based on cardiac tissue engineering. This limitation motivates the search for small, inexpensive molecules that would simultaneously be cardio-protective and vasculogenic. Here, we present peptide sequence QHREDGS, based upon the fibrinogen-like domain of angiopoietin-1, as a prime candidate molecule. We demonstrated previously that QHREDGS improved cardiomyocyte metabolism and mitigated serum starved apoptosis. In this paper we further demonstrate the potency of QHREDGS in its ability to enhance endothelial cell survival, metabolism and tube formation. When endothelial cells were exposed to the soluble form of QHREDGS, improvements in endothelial cell barrier functionality, nitric oxide production and cell metabolism (ATP levels in serum starved conditions were found. The functionality of the peptide was then examined when conjugated to collagen-chitosan hydrogel, a potential carrier for in vivo application. The presence of the peptide in the hydrogel mitigated paclitaxel induced apoptosis of endothelial cells in a dose dependent manner. Furthermore, the peptide modified hydrogels stimulated tube-like structure formation of encapsulated endothelial cells. When integrin αvβ3 or α5β1 were antibody blocked during cell encapsulation in peptide modified hydrogels, tube formation was abolished. Therefore, the dual protective nature of the novel peptide QHREDGS may position this peptide as an appealing augmentation for collagen-chitosan hydrogels that could be used for biomaterial delivered cell therapies in the settings of myocardial infarction.

  20. QHREDGS enhances tube formation, metabolism and survival of endothelial cells in collagen-chitosan hydrogels.

    Miklas, Jason W; Dallabrida, Susan M; Reis, Lewis A; Ismail, Nesreen; Rupnick, Maria; Radisic, Milica

    2013-01-01

    Cell survival in complex, vascularized tissues, has been implicated as a major bottleneck in advancement of therapies based on cardiac tissue engineering. This limitation motivates the search for small, inexpensive molecules that would simultaneously be cardio-protective and vasculogenic. Here, we present peptide sequence QHREDGS, based upon the fibrinogen-like domain of angiopoietin-1, as a prime candidate molecule. We demonstrated previously that QHREDGS improved cardiomyocyte metabolism and mitigated serum starved apoptosis. In this paper we further demonstrate the potency of QHREDGS in its ability to enhance endothelial cell survival, metabolism and tube formation. When endothelial cells were exposed to the soluble form of QHREDGS, improvements in endothelial cell barrier functionality, nitric oxide production and cell metabolism (ATP levels) in serum starved conditions were found. The functionality of the peptide was then examined when conjugated to collagen-chitosan hydrogel, a potential carrier for in vivo application. The presence of the peptide in the hydrogel mitigated paclitaxel induced apoptosis of endothelial cells in a dose dependent manner. Furthermore, the peptide modified hydrogels stimulated tube-like structure formation of encapsulated endothelial cells. When integrin αvβ3 or α5β1 were antibody blocked during cell encapsulation in peptide modified hydrogels, tube formation was abolished. Therefore, the dual protective nature of the novel peptide QHREDGS may position this peptide as an appealing augmentation for collagen-chitosan hydrogels that could be used for biomaterial delivered cell therapies in the settings of myocardial infarction. PMID:24013716

  1. An Effective Acid Combination for Enhanced Properties and Corrosion Control of Acidizing Sandstone Formation

    Umer Shafiq, Mian; Khaled Ben Mahmud, Hisham

    2016-03-01

    To fulfill the demand of the world energy, more technologies to enhance the recovery of oil production are being developed. Sandstone acidizing has been introduced and it acts as one of the important means to increase oil and gas production. Sandstone acidizing operation generally uses acids, which create or enlarge the flow channels of formation around the wellbore. In sandstone matrix acidizing, acids are injected into the formation at a pressure below the formation fracturing pressure, in which the injected acids react with mineral particles that may restrict the flow of hydrocarbons. Most common combination is Hydrofluoric Acid - Hydrochloric with concentration (3% HF - 12% HCl) known as mud acid. But there are some problems associated with the use of mud acid i.e., corrosion, precipitation. In this paper several new combinations of acids were experimentally screened to identify the most effective combination. The combinations used consist of fluoboric, phosphoric, formic and hydrofluoric acids. Cores were allowed to react with these combinations and results are compared with the mud acid. The parameters, which are analyzed, are Improved Permeability Ratio, strength and mineralogy. The analysis showed that the new acid combination has the potential to be used in sandstone acidizing.

  2. Enhancement of hybridoma formation, clonability and cell proliferation in a nanoparticle-doped aqueous environment

    Karnieli Ohad

    2008-01-01

    Full Text Available Abstract Background The isolation and production of human monoclonal antibodies is becoming an increasingly important pursuit as biopharmaceutical companies migrate their drug pipelines away from small organic molecules. As such, optimization of monoclonal antibody technologies is important, as this is becoming the new rate-limiting step for discovery and development of new pharmaceuticals. The major limitations of this system are the efficiency of isolating hybridoma clones, the process of stabilizing these clones and optimization of hybridoma cell secretion, especially for large-scale production. Many previous studies have demonstrated how perturbations in the aqueous environment can impact upon cell biology. In particular, radio frequency (RF irradiation of solutions can have dramatic effects on behavior of solutions, cells and in particular membrane proteins, although this effect decays following removal of the RF. Recently, it was shown that nanoparticle doping of RF irradiated water (NPD water produced a stabilized aqueous medium that maintained the characteristic properties of RF irradiated water for extended periods of time. Therefore, the ordering effect in water of the RF irradiation can now be studied in systems that required prolonged periods for analysis, such as eukaryotic cell culture. Since the formation of hybridoma cells involves the formation of a new membrane, a process that is affected by the surrounding aqueous environment, we tested these nanoparticle doped aqueous media formulations on hybridoma cell production. Results In this study, we tested the entire process of isolation and production of human monoclonal antibodies in NPD water as a means for further enhancing human monoclonal antibody isolation and production. Our results indicate an overall enhancement of hybridoma yield, viability, clonability and secretion. Furthermore, we have demonstrated that immortal cells proliferate faster whereas primary human fibroblasts

  3. Inhibiting actin depolymerization enhances osteoblast differentiation and bone formation in human stromal stem cells

    Chen, Li; Shi, Kaikai; Frary, Charles Edward;

    2015-01-01

    Remodeling of the actin cytoskeleton through actin dynamics is involved in a number of biological processes, but its role in human stromal (skeletal) stem cells (hMSCs) differentiation is poorly understood. In the present study, we demonstrated that stabilizing actin filaments by inhibiting gene...... expression of the two main actin depolymerizing factors (ADFs): Cofilin 1 (CFL1) and Destrin (DSTN) in hMSCs, enhanced cell viability and differentiation into osteoblastic cells (OB) in vitro, as well as heterotopic bone formation in vivo. Similarly, treating hMSC with Phalloidin, which is known to stabilize...... polymerized actin filaments, increased hMSCs viability and OB differentiation. Conversely, Cytocholasin D, an inhibitor of actin polymerization, reduced cell viability and inhibited OB differentiation of hMSC. At a molecular level, preventing Cofilin phosphorylation through inhibition of LIM domain kinase 1...

  4. Enhanced H2O formation through dust grain chemistry in X-ray exposed environments

    Meijerink, R; Spaans, M

    2011-01-01

    The ULIRG Mrk 231 exhibits very strong water rotational lines between \\lambda = 200-670\\mu m, comparable to the strength of the CO rotational lines. High redshift quasars also show similar CO and H2O line properties, while starburst galaxies, such as M82, lack these very strong H2O lines in the same wavelength range, but do show strong CO lines. We explore the possibility of enhancing the gas phase H2O abundance in X-ray exposed environments, using bare interstellar carbonaceous dust grains as a catalyst. Cloud-cloud collisions cause C and J shocks, and strip the grains of their ice layers. The internal UV field created by X-rays from the accreting black hole does not allow to reform the ice. We determine formation rates of both OH and H2O on dust grains, having temperature T_dust=10-60 K, using both Monte Carlo as well as rate equation method simulations. The acquired formation rates are added to our X-ray chemistry code, that allows us to calculate the thermal and chemical structure of the interstellar medi...

  5. Monodispersed bimetallic PdAg nanoparticles with twinned structures: Formation and enhancement for the methanol oxidation

    Yin, Zhen; Zhang, Yining; Chen, Kai; Li, Jing; Li, Wenjing; Tang, Pei; Zhao, Huabo; Zhu, Qingjun; Bao, Xinhe; Ma, Ding

    2014-03-01

    Monodispersed bimetallic PdAg nanoparticles can be fabricated through the emulsion-assisted ethylene glycol (EG) ternary system. Different compositions of bimetallic PdAg nanoparticles, Pd80Ag20, Pd65Ag35 and Pd46Ag54 can be obtained via adjusting the reaction parameters. For the formation process of the bimetallic PdAg nanoparticles, there have two-stage growth processes: firstly, nucleation and growth of the primary nanoclusters; secondly, formation of the secondary nanoparticles with the size-selection and relax process via the coalescence or aggregation of the primary nanoclusters. The as-prepared PdAg can be supported on the carbon black without any post-treatment, which exhibited high electro-oxidation activity towards methanol oxidation under alkaline media. More importantly, carbon-supported Pd80Ag20 nanoparticles reveal distinctly superior activities for the methanol oxidation, even if compared with commercial Pt/C electro-catalyst. It is concluded that the enhanced activity is dependant on the unique twinning structure with heterogeneous phase due to the dominating coalescence growth in EG ternary system.

  6. Prophage spontaneous activation promotes DNA release enhancing biofilm formation in Streptococcus pneumoniae.

    Margarida Carrolo

    Full Text Available Streptococcus pneumoniae (pneumococcus is able to form biofilms in vivo and previous studies propose that pneumococcal biofilms play a relevant role both in colonization and infection. Additionally, pneumococci recovered from human infections are characterized by a high prevalence of lysogenic bacteriophages (phages residing quiescently in their host chromosome. We investigated a possible link between lysogeny and biofilm formation. Considering that extracellular DNA (eDNA is a key factor in the biofilm matrix, we reasoned that prophage spontaneous activation with the consequent bacterial host lysis could provide a source of eDNA, enhancing pneumococcal biofilm development. Monitoring biofilm growth of lysogenic and non-lysogenic pneumococcal strains indicated that phage-infected bacteria are more proficient at forming biofilms, that is their biofilms are characterized by a higher biomass and cell viability. The presence of phage particles throughout the lysogenic strains biofilm development implicated prophage spontaneous induction in this effect. Analysis of lysogens deficient for phage lysin and the bacterial major autolysin revealed that the absence of either lytic activity impaired biofilm development and the addition of DNA restored the ability of mutant strains to form robust biofilms. These findings establish that limited phage-mediated host lysis of a fraction of the bacterial population, due to spontaneous phage induction, constitutes an important source of eDNA for the S. pneumoniae biofilm matrix and that this localized release of eDNA favors biofilm formation by the remaining bacterial population.

  7. Stem Cell-Soluble Signals Enhance Multilumen Formation in SMG Cell Clusters.

    Maruyama, C L M; Leigh, N J; Nelson, J W; McCall, A D; Mellas, R E; Lei, P; Andreadis, S T; Baker, O J

    2015-11-01

    Saliva plays a major role in maintaining oral health. Patients with salivary hypofunction exhibit difficulty in chewing and swallowing foods, tooth decay, periodontal disease, and microbial infections. At this time, treatments for hyposalivation are limited to medications (e.g., muscarinic receptor agonists: pilocarpine and cevimeline) that induce saliva secretion from residual acinar cells as well as artificial salivary substitutes. Therefore, advancement of restorative treatments is necessary to improve the quality of life in these patients. Our previous studies indicated that salivary cells are able to form polarized 3-dimensional structures when grown on growth factor-reduced Matrigel. This basement membrane is rich in laminin-III (L1), which plays a critical role in salivary gland formation. Mitotically inactive feeder layers have been used previously to support the growth of many different cell types, as they provide factors necessary for cell growth and organization. The goal of this study was to improve salivary gland cell differentiation in primary cultures by using a combination of L1 and a feeder layer of human hair follicle-derived mesenchymal stem cells (hHF-MSCs). Our results indicated that the direct contact of mouse submandibular (mSMG) cell clusters and hHF-MSCs was not required for mSMG cells to form acinar and ductal structures. However, the hHF-MSC conditioned medium enhanced cell organization and multilumen formation, indicating that soluble signals secreted by hHF-MSCs play a role in promoting these features. PMID:26285810

  8. Sfp-type PPTase inactivation promotes bacterial biofilm formation and ability to enhance wheat drought tolerance.

    Timmusk, Salme; Kim, Seong-Bin; Nevo, Eviatar; Abd El Daim, Islam; Ek, Bo; Bergquist, Jonas; Behers, Lawrence

    2015-01-01

    Paenibacillus polymyxa is a common soil bacterium with broad range of practical applications. An important group of secondary metabolites in P. polymyxa are non-ribosomal peptide and polyketide derived metabolites (NRPs/PKs). Modular non-ribosomal peptide synthetases catalyze main steps in the biosynthesis of the complex secondary metabolites. Here we report on the inactivation of an A26 Sfp-type 4'-phosphopantetheinyl transferase (Sfp-type PPTase). The inactivation of the gene resulted in loss of NRPs/PKs production. In contrast to the former Bacillus spp. model the mutant strain compared to wild type showed greatly enhanced biofilm formation ability. A26Δsfp biofilm promotion is directly mediated by NRPs/PKs, as exogenous addition of the wild type metabolite extracts restores its biofilm formation level. Wheat inoculation with bacteria that had lost their Sfp-type PPTase gene resulted in two times higher plant survival and about three times increased biomass under severe drought stress compared to wild type. Challenges with P. polymyxa genetic manipulation are discussed. PMID:26052312

  9. Enhancement of MgAl2O4 spinel formation from coprecipitated precursor by powder processing

    Soumen Pal; A K Bandyopadhyay; S Mukherjee; B N Samaddar; P G Pal

    2011-07-01

    Although low temperature fast coprecipitation technique has been used to synthesize stoichiometric (MgO–nAl2O3, = 1) MgAl2O4 spinel forming precursor, delayed spinellization has always been the concern in this process. In this article, the precursor of this ‘fast technique’ has been used for bulk production by further processing by high speed mixing with solvents and mechanical activation by attrition milling in terms of superior spinellization. At 1000°C, MgAl2O4 – -Al2O3 solid solution and MgO phases are formed (spinel formed by 1000°C is regarded as primary spinel). At higher temperatures, due to large agglomerate size, MgO can not properly interact with the exsolved -Al2O3 from spinel solid solution to form secondary spinel; and consequently spinellization gets affected. Solvent treatment and attrition milling of the coprecipitated precursor disintegrate the larger agglomerates into smaller size (effect is more in attrition). Then MgO comes in proper contact with exsolved alumina, and therefore total spinel formation (primary + secondary) is enhanced. Extent of spinellization, for processed calcined samples where some alumina exists as solid solution with spinel, can be determined from the percentage conversion of MgO. Analysis of the processed powders suggests that the 4 h attrited precursor is most effective in terms of nano size (< 25 nm) stoichiometric spinel crystallite formation at ≤ 1100°C.

  10. Enhanced apatite formation on Ti metal heated in PO2-controlled nitrogen atmosphere.

    Hashimoto, Masami; Hayashi, Kazumi; Kitaoka, Satoshi

    2013-10-01

    The oxynitridation of biomedical titanium metal under a precisely regulated oxygen partial pressure (PO2) of 10(-14)Pa in nitrogen atmosphere at 973 K for 1 h strongly enhanced apatite formation compared with that on Ti heated in air. The factors governing the high apatite-forming ability are discussed from the viewpoint of the surface properties of Ti heated under a PO2 of 10(-14)Pa in nitrogen atmosphere determined from X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and zeta potential measurements. Nitrogen (N)-doped TiO2 (interstitial N) was formed on pure Ti heated under a PO2 of 10(-14)Pa in nitrogen atmosphere at 973 K. The XPS O1s main peak shifted toward a lower binding energy upon heating under a PO2 of 10(-14)Pa. This shift may be due to the formation of oxygen vacancies. This Ti surface had a positive zeta potential of approximately 20 mV. According to time-of-flight secondary ion mass spectroscopy results, PO4(3-) ions were predominantly adsorbed on Ti soaked in simulated body fluid (SBF) after heat treatment, followed by calcium ions. It was concluded that the apatite formation kinetics can be described using the Avrami-Erofeev equation with an Avrami index of n=2, which implies the instantaneous nucleation of apatite on the surface of Ti soaked in SBF after heat treatment at 973 K under a PO2 of 10(-14)Pa. PMID:23910327

  11. Abundances of carbon-enhanced metal-poor stars as constraints on their formation

    Hansen, C J; Hansen, T T; Kennedy, C R; Placco, V M; Beers, T C; Andersen, J; Cescutti, G; Chiappini, C

    2015-01-01

    An increasing fraction of carbon-enhanced metal-poor (CEMP) stars is found as their iron abundance, [Fe/H], decreases below [Fe/H] = -2.0. The CEMP-s stars have the highest absolute carbon abundances, [C/H], and are thought to owe their enrichment in carbon and the slow neutron-capture (s-process) elements to mass transfer from a former asymptotic giant-branch (AGB) binary companion. The most Fe-poor CEMP stars are normally single, exhibit somewhat lower [C/H] than CEMP-s stars, but show no s-process element enhancement (CEMP-no stars). CNO abundance determinations offer clues to their formation sites. C, N, Sr, and Ba abundances (or limits) and 12C/13C ratios where possible are derived for a sample of 27 faint metal-poor stars for which the X-shooter spectra have sufficient S/N ratios. These moderate resolution, low S/N (~10-40) spectra prove sufficient to perform limited chemical tagging and enable assignment of these stars into the CEMP sub-classes (CEMP-s and CEMP-no). According to the derived abundances,...

  12. Detection of immunocomplex formation by enhanced photoluminescence of antibody-functionalized diatom biosilica

    Gale, Debra K.; Gutu, Timothy; Jiao, Jun; Chang, Chih-Hung; Rorrer, Gregory L.

    2009-05-01

    Diatoms are single-celled photosynthetic algae that make silica shells or "frustules" with intricate features patterned at the nano and microscales. In this study, antibody-functionalized diatom biosilica frustules serve as a biosensor platform for selective and label free antibody-antigen immunocomplex formation by enhanced photoluminescence. Biosilica frustules of 10 micron diameter were isolated from cells of the centric marine diatom Cyclotella sp. They were then mounted on glass and covalently functionalized with the model antibody Rabbit Immunoglobulin G (IgG) to yield a uniform nanostructured surface that selectively binds to its complimentary antigen, Goat anti-Rabbit IgG. Diatom frustules possess an intrinsic capacity to emit blue light when excited with a UV laser light source, a property called photoluminescence. Binding the antibody-functionalized diatom frustule with its complimentary antigen selectively enhanced the intrinsic photoluminescence intensity of the diatom frustule by a factor of three, whereas challenging the antibody-functionalized diatom frustule with a non-complimentary antigen, Goat anti-human IgG did not change the intrinsic photoluminescence intensity. The nucleophilic immunocomplex increases the photoluminescence by donating electrons to non-radiative sites on the photoluminescent diatom biosilica, thereby decreasing non-radiative electron decay and increasing radiative emission. The intensified photoluminescence intensity is correlated to the antigen, goat anti-rabbit IgG concentration, with a binding constant of 2.8 +/- 0.7x10-7 M.

  13. Exchange Protein Activated by cAMP Enhances Long-Term Memory Formation Independent of Protein Kinase A

    Ma, Nan; Abel, Ted; Hernandez, Pepe J.

    2009-01-01

    It is well established that cAMP signaling within neurons plays a major role in the formation of long-term memories--signaling thought to proceed through protein kinase A (PKA). However, here we show that exchange protein activated by cAMP (Epac) is able to enhance the formation of long-term memory in the hippocampus and appears to do so…

  14. Formative Assessment Practices in Built Environment Higher Education Programmes and the Enhancement of the Student Learning Experience

    Scott, Lloyd; Fortune, Chrisopher

    2011-01-01

    It is widely accepted across Higher Education (HE) that assessment has a strong link with learning and a key factor in this link is formative assessment. Formative assessment is generally defined as an activity taking place during a programme or unit of learning with the express purpose of improving and enhancing student learning. However, there is still considerable disagreement over the roles of lecturers and students in this process. It is therefore very important to understand how lecture...

  15. Abundances of carbon-enhanced metal-poor stars as constraints on their formation

    Hansen, C. J.; Nordström, B.; Hansen, T. T.; Kennedy, C. R.; Placco, V. M.; Beers, T. C.; Andersen, J.; Cescutti, G.; Chiappini, C.

    2016-04-01

    Context. An increasing fraction of carbon-enhanced metal-poor (CEMP) stars is found as their iron abundance, [Fe/H], decreases below [Fe/H] =-2.0. The CEMP-s stars have the highest absolute carbon abundances, [C/H], and are thought to owe their enrichment in carbon and the slow neutron-capture (s-process) elements to mass transfer from a former asymptotic giant branch (AGB) binary companion. The most Fe-poor CEMP stars are normally single, exhibit somewhat lower [C/H] than CEMP-s stars, but show no s-process element enhancement (CEMP-no stars). Abundance determinations of CNO offer clues to their formation sites. Aims: Our aim is to use the medium-resolution spectrograph X-Shooter/VLT to determine stellar parameters and abundances for C, N, Sr, and Ba in several classes of CEMP stars in order to further classify and constrain the astrophysical formation sites of these stars. Methods: Atmospheric parameters for our programme stars were estimated from a combination of V-K photometry, model isochrone fits, and estimates from a modified version of the SDSS/SEGUE spectroscopic pipeline. We then used X-Shooter spectra in conjunction with the 1D local thermodynamic equilibrium spectrum synthesis code MOOG, 1D ATLAS9 atmosphere models to derive stellar abundances, and, where possible, isotopic 12C/13C ratios. Results: Abundances (or limits) of C, N, Sr, and Ba are derived for a sample of 27 faint metal-poor stars for which the X-Shooter spectra have sufficient signal-to-noise ratios (S/N). These moderate resolution, low S/N (~10-40) spectra prove sufficient to perform limited chemical tagging and enable assignment of these stars into the CEMP subclasses (CEMP-s and CEMP-no). According to the derived abundances, 17 of our sample stars are CEMP-s and 3 are CEMP-no, while the remaining 7 are carbon-normal. For four CEMP stars, the subclassification remains uncertain, and two of them may be pulsating AGB stars. Conclusions: The derived stellar abundances trace the formation

  16. Enhancement effect of relative humidity on the formation and regional respiratory deposition of secondary organic aerosol

    Highlights: → We examine the effect of humidity on the formation of secondary organic aerosol (SOA). → We found the increase of humidity could enhance the SOA mass and number. → These changes did not alter the pattern of regional respiratory deposition of SOA. - Abstract: In this study, we investigated the effect of relative humidity (RH) on the formation of secondary organic aerosol (SOA) generated from the ozonolysis of d-limonene in an environmental chamber. The mass yield and the number concentration of SOA increased seven and eight times, respectively, when the RH increased from 18% to 82%. The measured total loss rates (apparent loss rates) of the number and mass concentration of SOA in the chamber ranged from 1.70 to 1.77 h-1 and from 2.51 to 2.61 h-1, respectively, at a controlled ventilation rate of 0.72 ± 0.04 h-1. The wall-deposition-loss-rate coefficient observed (1.00 ± 0.02 h-1) was approximate to the estimated value based on Zhao and Wu's model which includes the factors of turbulence, Brownian diffusion, turbophoresis and surface roughness. According to the ICRP (International Commission on Radiological Protection) model, the inhaled SOA particles are deposited primarily in the alveoli of the lung. The integrated alveolar deposited dose of the mass (surface area) of SOA over 3 h accounted for 74.0-74.8% (74.3-74.9%) of the total deposited dose at the investigated RH. Raising the RH resulted in the growth of SOA particle sizes and increment of the deposition dose but did not cause significant changes in the ratio of regional to the total respiratory deposition of SOA.

  17. Enhancement effect of relative humidity on the formation and regional respiratory deposition of secondary organic aerosol

    Yu, Kuo-Pin, E-mail: kpyu@ym.edu.tw [Institute of Environmental and Occupational Health Sciences, National Yang-Ming University, No. 155, Sec. 2, Linong Street, Taipei 11221, Taiwan (China); Lin, Chi-Chi [Department of Civil and Environmental Engineering, National University of Kaohsiung, No. 700, Kaohsiung University Rd., Kaohsiung 81148, Taiwan (China); Yang, Shang-Chun [Institute of Environmental and Occupational Health Sciences, National Yang-Ming University, No. 155, Sec. 2, Linong Street, Taipei 11221, Taiwan (China); Zhao Ping [Department of Civil and Environmental Engineering, National University of Kaohsiung, No. 700, Kaohsiung University Rd., Kaohsiung 81148, Taiwan (China)

    2011-07-15

    Highlights: {yields} We examine the effect of humidity on the formation of secondary organic aerosol (SOA). {yields} We found the increase of humidity could enhance the SOA mass and number. {yields} These changes did not alter the pattern of regional respiratory deposition of SOA. - Abstract: In this study, we investigated the effect of relative humidity (RH) on the formation of secondary organic aerosol (SOA) generated from the ozonolysis of d-limonene in an environmental chamber. The mass yield and the number concentration of SOA increased seven and eight times, respectively, when the RH increased from 18% to 82%. The measured total loss rates (apparent loss rates) of the number and mass concentration of SOA in the chamber ranged from 1.70 to 1.77 h{sup -1} and from 2.51 to 2.61 h{sup -1}, respectively, at a controlled ventilation rate of 0.72 {+-} 0.04 h{sup -1}. The wall-deposition-loss-rate coefficient observed (1.00 {+-} 0.02 h{sup -1}) was approximate to the estimated value based on Zhao and Wu's model which includes the factors of turbulence, Brownian diffusion, turbophoresis and surface roughness. According to the ICRP (International Commission on Radiological Protection) model, the inhaled SOA particles are deposited primarily in the alveoli of the lung. The integrated alveolar deposited dose of the mass (surface area) of SOA over 3 h accounted for 74.0-74.8% (74.3-74.9%) of the total deposited dose at the investigated RH. Raising the RH resulted in the growth of SOA particle sizes and increment of the deposition dose but did not cause significant changes in the ratio of regional to the total respiratory deposition of SOA.

  18. Nanolayer formation on titanium by phosphonated gelatin for cell adhesion and growth enhancement

    Zhou X

    2015-09-01

    Full Text Available Xiaoyue Zhou,1,2,* Shin-Hye Park,1,* Hongli Mao,3 Takashi Isoshima,1 Yi Wang,2 Yoshihiro Ito1,3 1Nano Medical Engineering Laboratory, RIKEN, Wako, Saitama, Japan; 2Department of Regenerative Medicine, School of Pharmaceutical Sciences, Jilin University, Changchun, Jilin, People’s Republic of China; 3Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science, Wako, Saitama, Japan *These authors contributed equally to this work Abstract: Phosphonated gelatin was prepared for surface modification of titanium to stimulate cell functions. The modified gelatin was synthesized by coupling with 3-aminopropylphosphonic acid using water-soluble carbodiimide and characterized by 31P nuclear magnetic resonance and gel permeation chromatography. Circular dichroism revealed no differences in the conformations of unmodified and phosphonated gelatin. However, the gelation temperature was changed by the modification. Even a high concentration of modified gelatin did not form a gel at room temperature. Time-of-flight secondary ion mass spectrometry showed direct bonding between the phosphonated gelatin and the titanium surface after binding. The binding behavior of phosphonated gelatin on the titanium surface was quantitatively analyzed by a quartz crystal microbalance. Ellipsometry showed the formation of a several nanometer layer of gelatin on the surface. Contact angle measurement indicated that the modified titanium surface was hydrophobic. Enhancement of the attachment and spreading of MC-3T3L1 osteoblastic cells was observed on the phosphonated gelatin-modified titanium. These effects on cell adhesion also led to growth enhancement. Phosphonation of gelatin was effective for preparation of a cell-stimulating titanium surface. Keywords: phosphonated gelatin, surface modification, titanium, cell adhesion

  19. Enhanced apatite formation on Ti metal heated in P{sub O2}-controlled nitrogen atmosphere

    Hashimoto, Masami, E-mail: masami@jfcc.or.jp; Hayashi, Kazumi, E-mail: k_hayashi@jfcc.or.jp; Kitaoka, Satoshi, E-mail: kitaoka@jfcc.or.jp

    2013-10-15

    The oxynitridation of biomedical titanium metal under a precisely regulated oxygen partial pressure (P{sub O2}) of 10{sup −14} Pa in nitrogen atmosphere at 973 K for 1 h strongly enhanced apatite formation compared with that on Ti heated in air. The factors governing the high apatite-forming ability are discussed from the viewpoint of the surface properties of Ti heated under a P{sub O2} of 10{sup −14} Pa in nitrogen atmosphere determined from X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and zeta potential measurements. Nitrogen (N)-doped TiO{sub 2} (interstitial N) was formed on pure Ti heated under a P{sub O2} of 10{sup −14} Pa in nitrogen atmosphere at 973 K. The XPS O1s main peak shifted toward a lower binding energy upon heating under a P{sub O2} of 10{sup −14} Pa. This shift may be due to the formation of oxygen vacancies. This Ti surface had a positive zeta potential of approximately 20 mV. According to time-of-flight secondary ion mass spectroscopy results, PO{sub 4}{sup 3−} ions were predominantly adsorbed on Ti soaked in simulated body fluid (SBF) after heat treatment, followed by calcium ions. It was concluded that the apatite formation kinetics can be described using the Avrami–Erofeev equation with an Avrami index of n = 2, which implies the instantaneous nucleation of apatite on the surface of Ti soaked in SBF after heat treatment at 973 K under a P{sub O2} of 10{sup −14} Pa. - Highlights: • Nitrogen-doped TiO{sub 2} was formed on Ti heated under a P{sub O2} of 10{sup −14} Pa. • Oxygen vacancy was existed on the outermost layer of nitrogen-doped TiO{sub 2}. • This nitrogen-doped TiO{sub 2} surface had a positive zeta potential of 20 mV. • PO{sub 4}{sup 3−} ions were predominantly adsorbed on the nitrogen-doped TiO{sub 2} soaked in SBF.

  20. Enhancing the formation of tetragonal phase in perovskite nanocrystals using an ultrasound assisted wet chemical method.

    Moghtada, Abdolmajid; Ashiri, Rouholah

    2016-11-01

    Synthesis of highly-pure tetragonal perovskite nanocrystals is the key challenge facing the development of new electronic devices. Our results have indicated that ultrasonication is able in enhancing the formation of tetragonal phase in perovskite nanocrystals. In the current research, multicationic oxide perovskite (ATiO3; A: Ba, Sr, Ba0.6Sr0.4) nanopowders are synthesized successfully by a general methodology without a calcination step. The method is able to synthesize high-purity nanoscale ATiO3 (BaTiO3, SrTiO3, Ba0.6Sr0.4TiO3) with tetragonal symmetry at a lower temperature and in a shorter time span in contrast to the literature. To reach an in-depth understanding of the scientific basis of the proposed methodology, in-detail analysis was carried out via XRD, FTIR, FT-Raman, FE-SEM and HR-TEM. The effects of the sonication time and sonication (bath) temperature on the tetragonality of nanoscale products were examined. Furthermore, Raman spectroscopy provides clear evidence for local tetragonal symmetries, in particular when a band is observed at 310cm(-1). PMID:27245965

  1. Enhancement of committed hematopoietic stem cell colony formation by nandrolone decanoate after sublethal whole body irradiation

    The ability of an anabolic steroid, nandrolone decanoate, to increase committed topoietic stem cell (CFU-gm, CFU-e, and BFU-e) colony formation after sublethal irradiation was evaluated. Immediately after receiving whole body irradiation and on the next two days, each mouse was injected intraperitoneally with nandrolone decanoate (1.25 mg) in propylene glycol. Irradiated control mice received only propylene glycol. Compared to controls, drug-treated mice showed marked peripheral blood leukocytosis and more stable packed red cell volume. Drug-treated mice also demonstrated increased erythropoiesis, as CFU-e/BFU-e concentrations from both marrow (9% to 581%) and spleen (15% to 797%) were elevated. Granulopoiesis was increased similarly, as CFU-gm concentrations from marrow (38% to 685%) and spleen (9% to 373%) were elevated. These results demonstrate that nandrolone decanoate enhances hematopoietic stem cell recovery after sublethal whole body irradiation. This suggests that following hematopoietic suppression, nandrolone decanoate may stimulate the recovery of hematopoiesis at the stem cell level and in peripheral blood

  2. Enhancement of beam pulse controllability for a single-pulse formation system of a cyclotron

    Kurashima, Satoshi, E-mail: kurashima.satoshi@jaea.go.jp; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Okumura, Susumu [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Taguchi, Mitsumasa [Quantum Beam Science Center, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Fukuda, Mitsuhiro [Research Center for Nuclear Physics, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)

    2015-07-15

    The single-pulse formation technique using a beam chopping system consisting of two types of high-voltage beam kickers was improved to enhance the quality and intensity of the single-pulse beam with a pulse interval over 1 μs at the Japan Atomic Energy Agency cyclotron facility. A contamination rate of neighboring beam bunches in the single-pulse beam was reduced to less than 0.1%. Long-term purification of the single pulse beam was guaranteed by the well-controlled magnetic field stabilization system for the cyclotron magnet. Reduction of the multi-turn extraction number for suppressing the neighboring beam bunch contamination was achieved by restriction of a beam phase width and precise optimization of a particle acceleration phase. In addition, the single-pulse beam intensity was increased by a factor of two or more by a combination of two types of beam bunchers using sinusoidal and saw-tooth voltage waveforms. Provision of the high quality intense single-pulse beam contributed to improve the accuracy of experiments for investigation of scintillation light time-profile and for neutron energy measurement by a time-of-flight method.

  3. 3D molecular line formation in dwarf carbon-enhanced metal-poor stars

    Behara, N T; Bonifacio, P; Sbordone, L; Hernandez, J I Gonzalez; Caffau, E

    2009-01-01

    We present a detailed analysis of the carbon and nitrogen abundances of two dwarf carbon-enhanced metal-poor (CEMP) stars: SDSS J1349-0229 and SDSS J0912+0216. We also report the oxygen abundance of SDSS J1349-0229. These stars are metal-poor, with [Fe/H] < -2.5, and were selected from our ongoing survey of extremely metal-poor dwarf candidates from the Sloan Digital SkySurvey (SDSS). The carbon, nitrogen and oxygen abundances rely on molecular lines which form in the outer layers of the stellar atmosphere. It is known that convection in metal-poor stars induces very low temperatures which are not predicted by `classical' 1D stellar atmospheres. To obtain the correct temperature structure, one needs full 3D hydrodynamical models. Using CO5BOLD 3D hydrodynamical model atmospheres and the Linfor3D line formation code, molecular lines of CH, NH, OH and C2 were computed, and 3D carbon, nitrogen and oxygen abundances were determined. The resulting carbon abundances were compared to abundances derived using atom...

  4. Erbium enhanced formation and growth of photoluminescent Er/Si nanocrystals

    Photoluminescent Er/Si-nanocrystal composites were obtained after annealing Er doped silicon suboxide (SiOx) thin films. The films were prepared by reactive sputtering (Ar/O2 atmosphere) with a pure silicon target partially covered with metallic Er. The presence of Er in the resulting films strongly influences Si nanocrystal nucleation and growth during thermal treatment at temperatures between 300 and 1300 °C. A correlation between Er photoluminescence (PL) spectra, Er speciation and Si nanocrystal properties indicated that PL bands and their intensity are directly influenced by the nanocrystal size and density, and their vicinity to the Er3+ centers. This correlation is explained by considering Er centers as promotor for SiOx disproportionation, locally increasing Si0 concentration which leads to formation of Si nanocrystals in the vicinity of Er. - Highlights: • Photolumininescent Er/Si-nanocrystal growth in co-sputtered Er/SiOx thin films. • Upon annealing Er enhances SiOx disproportionation, nanocrystal nucleation and growth. • Er3+ coordination increase with increasing SiOx disproportionation

  5. Erbium enhanced formation and growth of photoluminescent Er/Si nanocrystals

    Mustafa, Danilo, E-mail: dmustafa@iq.usp.br [KULeuven - Center for Surface Chemistry and Catalysis, Department of Microbial and Molecular Systems, kasteelpark arenberg 23 - box 2461, B-3001 Heverlee (Belgium); Biggemann, Daniel [Laboratório Nacional de Luz Síncrotron, LNLS, Campinas, SP, C. P. 6192, 13083–970 (Brazil); Martens, Johan A.; Kirschhock, Christine E.A. [KULeuven - Center for Surface Chemistry and Catalysis, Department of Microbial and Molecular Systems, kasteelpark arenberg 23 - box 2461, B-3001 Heverlee (Belgium); Tessler, Leandro R. [Instituto de Física “Gleb Wataghin”, Universidade Estadual de Campinas, UNICAMP, Campinas, SP, C. P. 6165, 13083–970 (Brazil); Breynaert, Eric [KULeuven - Center for Surface Chemistry and Catalysis, Department of Microbial and Molecular Systems, kasteelpark arenberg 23 - box 2461, B-3001 Heverlee (Belgium)

    2013-06-01

    Photoluminescent Er/Si-nanocrystal composites were obtained after annealing Er doped silicon suboxide (SiO{sub x}) thin films. The films were prepared by reactive sputtering (Ar/O{sub 2} atmosphere) with a pure silicon target partially covered with metallic Er. The presence of Er in the resulting films strongly influences Si nanocrystal nucleation and growth during thermal treatment at temperatures between 300 and 1300 °C. A correlation between Er photoluminescence (PL) spectra, Er speciation and Si nanocrystal properties indicated that PL bands and their intensity are directly influenced by the nanocrystal size and density, and their vicinity to the Er{sup 3+} centers. This correlation is explained by considering Er centers as promotor for SiO{sub x} disproportionation, locally increasing Si{sup 0} concentration which leads to formation of Si nanocrystals in the vicinity of Er. - Highlights: • Photolumininescent Er/Si-nanocrystal growth in co-sputtered Er/SiO{sub x} thin films. • Upon annealing Er enhances SiOx disproportionation, nanocrystal nucleation and growth. • Er{sup 3+} coordination increase with increasing SiOx disproportionation.

  6. Extracellular matrix formation enhances the ability of Streptococcus pneumoniae to cause invasive disease.

    Claudia Trappetti

    Full Text Available During infection, pneumococci exist mainly in sessile biofilms rather than in planktonic form, except during sepsis. However, relatively little is known about how biofilms contribute to pneumococcal pathogenesis. Here, we carried out a biofilm assay on opaque and transparent variants of a clinical serotype 19F strain WCH159. After 4 days incubation, scanning electron microscopy revealed that opaque biofilm bacteria produced an extracellular matrix, whereas the transparent variant did not. The opaque biofilm-derived bacteria translocated from the nasopharynx to the lungs and brain of mice, and showed 100-fold greater in vitro adherence to A549 cells than transparent bacteria. Microarray analysis of planktonic and sessile bacteria from transparent and opaque variants showed differential gene expression in two operons: the lic operon, which is involved in choline uptake, and in the two-component system, ciaRH. Mutants of these genes did not form an extracellular matrix, could not translocate from the nasopharynx to the lungs or the brain, and adhered poorly to A549 cells. We conclude that only the opaque phenotype is able to form extracellular matrix, and that the lic operon and ciaRH contribute to this process. We propose that during infection, extracellular matrix formation enhances the ability of pneumococci to cause invasive disease.

  7. Enhancement of beam pulse controllability for a single-pulse formation system of a cyclotron

    The single-pulse formation technique using a beam chopping system consisting of two types of high-voltage beam kickers was improved to enhance the quality and intensity of the single-pulse beam with a pulse interval over 1 μs at the Japan Atomic Energy Agency cyclotron facility. A contamination rate of neighboring beam bunches in the single-pulse beam was reduced to less than 0.1%. Long-term purification of the single pulse beam was guaranteed by the well-controlled magnetic field stabilization system for the cyclotron magnet. Reduction of the multi-turn extraction number for suppressing the neighboring beam bunch contamination was achieved by restriction of a beam phase width and precise optimization of a particle acceleration phase. In addition, the single-pulse beam intensity was increased by a factor of two or more by a combination of two types of beam bunchers using sinusoidal and saw-tooth voltage waveforms. Provision of the high quality intense single-pulse beam contributed to improve the accuracy of experiments for investigation of scintillation light time-profile and for neutron energy measurement by a time-of-flight method

  8. Using Argument Visualization to Enhance e-Participation in the Legislation Formation Process

    Loukis, Euripidis; Xenakis, Alexandros; Tseperli, Nektaria

    Most public policy problems are ‘wicked’, being characterised by high complexity, many heterogeneous views and conflicts among various stakeholders. Therefore citizens interested to participate in such debates in order to be sufficiently informed should study large amounts of relevant material, such as reports, laws, committees’ minutes, etc., which are in legalistic or in other specialist languages, or very often their substance is hidden in political rhetoric, putting barriers to a meaningful participation. In this paper we present the results of the research we have conducted for addressing this problem through the use of ‘Computer Supported Argument Visualization’ (CSAV) methods for supporting and enhancing e-participation in the legislation formation process. This approach has been implemented in a pilot e-participation project and then evaluated using both quantitative and qualitative methods based on the ‘Technology Acceptance Model’ (TAM), with positive results. Based on the conclusions of this evaluation an enrichment of the IBIS framework has been developed for improving the visualization of legal documents.

  9. Enhancement of committed hematopoietic stem cell colony formation by nandrolone decanoate after sublethal whole body irradiation

    Gallicchio, V.S.; Chen, M.G.; Watts, T.D.

    1984-11-01

    The ability of an anabolic steroid, nandrolone decanoate, to increase committed topoietic stem cell (CFU-gm, CFU-e, and BFU-e) colony formation after sublethal irradiation was evaluated. Immediately after receiving whole body irradiation and on the next two days, each mouse was injected intraperitoneally with nandrolone decanoate (1.25 mg) in propylene glycol. Irradiated control mice received only propylene glycol. Compared to controls, drug-treated mice showed marked peripheral blood leukocytosis and more stable packed red cell volume. Drug-treated mice also demonstrated increased erythropoiesis, as CFU-e/BFU-e concentrations from both marrow (9% to 581%) and spleen (15% to 797%) were elevated. Granulopoiesis was increased similarly, as CFU-gm concentrations from marrow (38% to 685%) and spleen (9% to 373%) were elevated. These results demonstrate that nandrolone decanoate enhances hematopoietic stem cell recovery after sublethal whole body irradiation. This suggests that following hematopoietic suppression, nandrolone decanoate may stimulate the recovery of hematopoiesis at the stem cell level and in peripheral blood.

  10. Formation of marine snow and enhanced enzymatic activities in oil-contaminated seawater

    Ziervogel, K.; McKay, L.; Yang, T.; Rhodes, B.; Nigro, L.; Gutierrez, T.; Teske, A.; Arnosti, C.

    2010-12-01

    The fate of oil spilled into the ocean depends on its composition, as well as on biological, chemical, and physical characteristics of the spill site. We investigated the effects of oil addition from the Deepwater Horizon (DH) spill on otherwise uncontaminated water collected close to the spill site. Incubation on a roller table mimicked the physical dynamics of natural seawater, leading to the formation of marine snow-oil aggregates. We measured the enzymatic activities of heterotrophic microbes associated with the aggregates and in the surrounding water, and assessed microbial population and community composition as oil-marine snow aggregates formed and aged in the water. Surface seawater taken near the spill site in May 2010 that had no visible crude oil was incubated in 1-l glass bottles with (oil-bottles) and without (no-oil bottles) a seawater-oil mixture collected from the same site. In the oil-bottles formation of brownish, densely packed marine snow (2-3 cm diameter) was observed within the first hour of the roller table incubation. In contrast no-oil bottles showed aggregate formation only after 3 days, and aggregates were almost transparent, less abundant, and smaller in size (roller table incubation, and analyzed for bacterial abundance and community structure as well as the activities of hydrolytic enzymes that are used by heterotrophic bacteria to degrade organic matter. We monitored oil-degrading activities with MUF-stearate and -butyrate, and also measured b-glucosidase, alkaline phosphatase, aminopeptidase, and six different polysaccharide hydrolase activities. Enzymatic activities were up to one order of magnitude higher in the oil-bottles compared with the no-oil bottles throughout the entire incubation time. Butyrate hydrolysis was elevated throughout the time course of the incubation, and stearate hydrolysis was particularly high over the initial 10 days. Activities of enzymes not directly associated with metabolism of oil were also enhanced

  11. Disruption of protein kinase Ceta results in impairment of wound healing and enhancement of tumor formation in mouse skin carcinogenesis.

    Chida, Kazuhiro; Hara, Takeshi; Hirai, Takaaki; Konishi, Chieko; Nakamura, Kenji; Nakao, Kazuki; Aiba, Atsu; Katsuki, Motoya; Kuroki, Toshio

    2003-05-15

    We have generated a mouse strain lacking protein kinase C (PKC) eta to evaluate its significance in epithelial organization and tumor formation. The PKCeta-deficient mice exhibited increased susceptibility to tumor formation in two-stage skin carcinogenesis by single application of 7,12-dimethylbenz(a)anthracene (DMBA) for tumor initiation and repeated applications of 12-O-tetradecanoylphorbol-13-acetate (TPA) for tumor promotion. The tumor formation was not enhanced by DMBA or TPA treatment alone, suggesting that PKCeta suppresses tumor promotion. Epidermal hyperplasia induced by topical TPA treatment was prolonged in the mutant mice. The enhanced tumor formation may be closely associated with the prolonged hyperplasia induced by topical TPA treatment. In the mutant mice, after inflicting injury by punch biopsy, wound healing on the dorsal skin, particularly reepithelialization, was significantly delayed and impaired in structure. Impairment of epithelial regeneration in wound healing indicates a possibility that PKCeta plays a role in maintenance of epithelial architecture. Homeostasis in epithelial tissues mediated by PKCeta is important for tumor formation in vivo. We propose that PKCeta is involved in tumor formation modulated by regulation of proliferation and remodeling of epithelial cells in vivo. PMID:12750259

  12. Enhanced actin pedestal formation by enterohemorrhagic Escherichia coli O157:H7 adapted to the mammalian host.

    MichaelJohnBrady

    2011-11-01

    Full Text Available Upon intestinal colonization, enterohemorrhagic Escherichia coli (EHEC induces epithelial cells to generate actin “pedestals” beneath bound bacteria, lesions that promote colonization. To induce pedestals, EHEC utilizes a type III secretion system to translocate into the mammalian cell bacterial effectors such as Tir, which localizes in the mammalian cell membrane and functions as a receptor for the bacterial outer membrane protein intimin. Whereas EHEC triggers efficient pedestal formation during mammalian infection, EHEC cultured in vitro induces pedestals on cell monolayers with relatively low efficiency. To determine whether growth within the mammalian host enhances EHEC pedestal formation, we compared in vitro-cultivated bacteria with EHEC directly isolated from infected piglets. Mammalian adaptation by EHEC was associated with a dramatic increase in the efficiency of cell attachment and pedestal formation. The amounts of intimin and Tir were significantly higher in host-adapted than in in vitro-cultivated bacteria, but increasing intimin or Tir expression, or artificially increasing the level of bacterial attachment to mammalian cells, did not enhance pedestal formation by in vitro-cultivated EHEC. Instead, a functional assay suggested that host-adapted EHEC translocate Tir much more efficiently than does in vitro-cultivated bacteria. These data suggest that adaptation of EHEC to the mammalian intestine enhances bacterial cell attachment, expression of intimin and Tir, and translocation of effectors that promote actin signaling.

  13. Heterozygous inactivation of the Nf1 gene in myeloid cells enhances neointima formation via a rosuvastatin-sensitive cellular pathway.

    Stansfield, Brian K; Bessler, Waylan K; Mali, Raghuveer; Mund, Julie A; Downing, Brandon; Li, Fang; Sarchet, Kara N; DiStasi, Matthew R; Conway, Simon J; Kapur, Reuben; Ingram, David A

    2013-03-01

    Mutations in the NF1 tumor suppressor gene cause Neurofibromatosis type 1 (NF1). Neurofibromin, the protein product of NF1, functions as a negative regulator of Ras activity. Some NF1 patients develop cardiovascular disease, which represents an underrecognized disease complication and contributes to excess morbidity and mortality. Specifically, NF1 patients develop arterial occlusion resulting in tissue ischemia and sudden death. Murine studies demonstrate that heterozygous inactivation of Nf1 (Nf1(+/-)) in bone marrow cells enhances neointima formation following arterial injury. Macrophages infiltrate Nf1(+/-) neointimas, and NF1 patients have increased circulating inflammatory monocytes in their peripheral blood. Therefore, we tested the hypothesis that heterozygous inactivation of Nf1 in myeloid cells is sufficient for neointima formation. Specific ablation of a single copy of the Nf1 gene in myeloid cells alone mobilizes a discrete pro-inflammatory murine monocyte population via a cell autonomous and gene-dosage dependent mechanism. Furthermore, lineage-restricted heterozygous inactivation of Nf1 in myeloid cells is sufficient to reproduce the enhanced neointima formation observed in Nf1(+/-) mice when compared with wild-type controls, and homozygous inactivation of Nf1 in myeloid cells amplified the degree of arterial stenosis after arterial injury. Treatment of Nf1(+/-) mice with rosuvastatin, a stain with anti-inflammatory properties, significantly reduced neointima formation when compared with control. These studies identify neurofibromin-deficient myeloid cells as critical cellular effectors of Nf1(+/-) neointima formation and propose a potential therapeutic for NF1 cardiovascular disease. PMID:23197650

  14. Enhanced formation of silver nanoparticles in Ag+-NOM-iron(II, III) systems and antibacterial activity studies.

    Adegboyega, Nathaniel F; Sharma, Virender K; Siskova, Karolina M; Vecerova, Renata; Kolar, Milan; Zbořil, Radek; Gardea-Torresdey, Jorge L

    2014-03-18

    This work reports the role of iron redox pair (Fe(3+)/Fe(2+)) in the formation of naturally occurring silver nanoparticles (AgNPs) in the aquatic environment. The results showed that Fe(3+) or Fe(2+) ions in the mixtures of Ag(+) and natural organic matter enhanced the formation of AgNPs. The formation of AgNPs depended on pH and types of organic matter. Increase in pH enhanced the formation of AgNPs, and humic acids as ligands showed higher formation of AgNPs compared to fulvic acids. The observed results were described by considering the potentials of redox pairs of silver and iron species and the possible species involved in reducing silver ions to AgNPs. Dynamic light scattering and transmission electron microscopy measurements of AgNPs revealed mostly bimodal size distribution with decrease in size of AgNPs due to iron species in the reaction mixture. Minimum inhibitory concentration of AgNPs needed to inhibit the growth of various bacterial species suggested the role of surfaces of tested Gram-positive and Gram-negative bacteria. Stability study of AgNPs, formed in Ag(+)-humic acid/fulvic acids-Fe(3+) mixtures over a period of several months showed high stability of the particles with significant increase in surface plasmon resonance peak. The environmental implications of the results in terms of fate, transport, and ecotoxicity of organic-coated AgNPs are briefly presented. PMID:24524189

  15. Adipokinetic hormone enhances nodule formation and phenoloxidase activation in adult locusts injected with bacterial lipopolysaccharide

    Goldsworthy, Graham J.; Chandrakant, S.; Opoku-Ware, K.

    2003-01-01

    Interactions between the locust endocrine and immune systems have been studied in vivo in relation to nodule formation and activation of the prophenoloxidase cascade in the haemolymph. Injection of bacterial lipopolysaccharide (LPS) extracted from Escherichia coli induces nodule formation in larval and adult locusts but does not increase phenoloxidase activity in the haemolymph. Nodule formation starts rapidly after injection of LPS and is virtually complete within 8 h, nodules occurring main...

  16. A myostatin and activin decoy receptor enhances bone formation in mice.

    Bialek, P; Parkington, J; Li, X; Gavin, D; Wallace, C; Zhang, J; Root, A; Yan, G; Warner, L; Seeherman, H J; Yaworsky, P J

    2014-03-01

    Myostatin is a member of the bone morphogenetic protein/transforming growth factor-β (BMP/TGFβ) super-family of secreted differentiation factors. Myostatin is a negative regulator of muscle mass as shown by increased muscle mass in myostatin deficient mice. Interestingly, these mice also exhibit increased bone mass suggesting that myostatin may also play a role in regulating bone mass. To investigate the role of myostatin in bone, young adult mice were administered with either a myostatin neutralizing antibody (Mstn-mAb), a soluble myostatin decoy receptor (ActRIIB-Fc) or vehicle. While both myostatin inhibitors increased muscle mass, only ActRIIB-Fc increased bone mass. Bone volume fraction (BV/TV), as determined by microCT, was increased by 132% and 27% in the distal femur and lumbar vertebrae, respectively. Histological evaluation demonstrated that increased BV/TV in both locations was attributed to increased trabecular thickness, trabecular number and bone formation rate. Increased BV/TV resulted in enhanced vertebral maximum compressive force compared to untreated animals. The fact that ActRIIB-Fc, but not Mstn-mAb, increased bone volume suggested that this soluble decoy receptor may be binding a ligand other than myostatin, that plays a role in regulating bone mass. This was confirmed by the significant increase in BV/TV in myostatin deficient mice treated with ActRIIB-Fc. Of the other known ActRIIB-Fc ligands, BMP3 has been identified as a negative regulator of bone mass. However, BMP3 deficient mice treated with ActRIIB-Fc showed similar increases in BV/TV as wild type (WT) littermates treated with ActRIIB-Fc. This result suggests that BMP3 neutralization is not the mechanism responsible for increased bone mass. The results of this study demonstrate that ActRIIB-Fc increases both muscle and bone mass in mice. Therefore, a therapeutic that has this dual activity represents a potential approach for the treatment of frailty. PMID:24333131

  17. Microbial and Chemical Enhancement of In-Situ Carbon Mineralization in Geological Formation

    Matter, J.; Chandran, K.

    2013-05-31

    Predictions of global energy usage suggest a continued increase in carbon emissions and rising concentrations of CO{sub 2} in the atmosphere unless major changes are made to the way energy is produced and used. Various carbon capture and storage (CCS) technologies are currently being developed, but unfortunately little is known regarding the fundamental characteristics of CO{sub 2}-mineral reactions to allow a viable in-situ carbon mineralization that would provide the most permanent and safe storage of geologically-injected CO{sub 2}. The ultimate goal of this research project was to develop a microbial and chemical enhancement scheme for in-situ carbon mineralization in geologic formations in order to achieve long-term stability of injected CO{sub 2}. Thermodynamic and kinetic studies of CO{sub 2}-mineral-brine systems were systematically performed to develop the in-situ mineral carbonation process that utilizes organic acids produced by a microbial reactor. The major participants in the project are three faculty members and their graduate and undergraduate students at the School of Engineering and Applied Science and at the Lamont-Doherty Earth Observatory at Columbia University: Alissa Park in Earth and Environmental Engineering & Chemical Engineering (PI), Juerg Matter in Earth and Environmental Science (Co-PI), and Kartik Chandran in Earth and Environmental Engineering (Co-PI). Two graduate students, Huangjing Zhao and Edris Taher, were trained as a part of this project as well as a number of graduate students and undergraduate students who participated part-time. Edris Taher received his MS degree in 2012 and Huangjing Zhao will defend his PhD on Jan. 15th, 2014. The interdisciplinary training provided by this project was valuable to those students who are entering into the workforce in the United States. Furthermore, the findings from this study were and will be published in referred journals to disseminate the results. The list of the papers is given at

  18. NF-kB directs dynamic super enhancer formation in inflammation and atherogenesis

    Griffin, Gabriel; Federation, Alexander; Paranal, Ronald M.; Bair, Steven; Newton, Gail; Lichtman, Andrew; Kung, Andrew; Yang, Tianlun; Wang, Hong; Luscinskas, Francis W.; Croce, Kevin; Bradner, James E.; Plutzky, Jorge

    2014-01-01

    SUMMARY Proinflammatory stimuli elicit rapid transcriptional responses via transduced signals to master regulatory transcription factors. To explore the role of chromatin-dependent signal transduction in the atherogenic inflammatory response, we characterized the dynamics, structure and function of regulatory elements in the activated endothelial cell epigenome. Stimulation with tumor necrosis factor alpha prompted a dramatic and rapid global redistribution of chromatin activators to massive de novo clustered enhancer domains. Inflammatory super enhancers formed by NF-κB accumulate at the expense of immediately decommissioned, basal endothelial super enhancers, despite persistent histone hyperacetylation. Mass action of enhancer factor redistribution causes momentous swings in transcriptional initiation and elongation. A chemical genetic approach reveals a requirement for BET bromodomains in communicating enhancer remodeling to RNA polymerase and orchestrating the transition to the inflammatory cell state, demonstrated in activated endothelium and macrophages. BET bromodomain inhibition abrogates super enhancer mediated inflammatory transcription, atherogenic endothelial responses and atherosclerosis in vivo. PMID:25263595

  19. Fibrinogen Induces Biofilm Formation by Streptococcus suis and Enhances Its Antibiotic Resistance▿

    Bonifait, Laetitia; Grignon, Louis; Grenier, Daniel

    2008-01-01

    In this study, we showed that supplementing the culture medium with fibrinogen induced biofilm formation by Streptococcus suis in a dose-dependent manner. Biofilm-grown S. suis cells were much more resistant to penicillin G than planktonic cells. S. suis bound fibrinogen to its surface, a property that likely contributes to biofilm formation.

  20. Characterization for Binding Complex Formation with Site-Directly Immobilized Antibodies Enhancing Detection Capability of Cardiac Troponin I

    Il-Hoon Cho; Sung-Min Seo; Jin-Woo Jeon; Se-Hwan Paek

    2009-01-01

    The enhanced analytical performances of immunoassays that employed site-directly immobilized antibodies as the capture binders have been functionally characterized in terms of antigen-antibody complex formation on solid surfaces. Three antibody species specific to cardiac troponin I, immunoglobulin G (IgG), Fab, and F(ab′)2 were site-directly biotinylated within the hinge region and then immobilized via a streptavidin-biotin linkage. The new binders were more efficient capture antibodies ...

  1. Study on Sensory Quality, Antioxidant Properties, and Maillard Reaction Products Formation in Rye-Buckwheat Cakes Enhanced with Selected Spices

    Małgorzata Przygodzka; Henryk Zieliński; Zuzana Ciesarová; Kristina Kukurová; Grzegorz Lamparski

    2015-01-01

    The effect of selected spices included in the recipe of rye-buckwheat cakes on sensory quality, nutritional value, and Maillard reaction (MR) products formation was addressed in this study. The cakes with cloves, nutmeg, allspice, cinnamon, vanilla, and spice mix addition revealed the highest overall quality values. Cakes enriched with cloves, allspice, and spice mix showed the highest rutin content and almost threefold higher available lysine contents whereas cakes enhanced with mix, cloves,...

  2. Demineralized Bone Matrix Injection in Consolidation Phase Enhances Bone Regeneration in Distraction Osteogenesis via Endochondral Bone Formation

    Kim, Ji-Beom; Lee, Dong Yeon; Seo, Sang Gyo; Kim, Eo Jin; Kim, Ji Hye; Yoo, Won Joon; Cho, Tae-Joon; Choi, In Ho

    2015-01-01

    Background Distraction osteogenesis (DO) is a promising tool for bone and tissue regeneration. However, prolonged healing time remains a major problem. Various materials including cells, cytokines, and growth factors have been used in an attempt to enhance bone formation. We examined the effect of percutaneous injection of demineralized bone matrix (DBM) during the consolidation phase on bone regeneration after distraction. Methods The immature rabbit tibial DO model (20 mm length-gain) was u...

  3. Surface-enhanced Raman scattering (SERS) revealing chemical variation during biofilm formation: from initial attachment to mature biofilm

    Chao, Yuanqing; Tong ZHANG

    2012-01-01

    Surface-enhanced Raman scattering (SERS) has recently been proved to be a promising technique for characterizing the chemical composition of the biofilm matrix. In the present study, to fully understand the chemical variations during biofilm formation, SERS based on silver colloidal nanoparticles was applied to evaluate the chemical components in the matrix of biofilm at different growth phases, including initial attached bacteria, colonies, and mature biofilm. Meanwhile, atomic force microsc...

  4. Mg(2+)/Ca(2+) promotes the adhesion of marine bacteria and algae and enhances following biofilm formation in artificial seawater.

    He, Xiaoyan; Wang, Jinpeng; Abdoli, Leila; Li, Hua

    2016-10-01

    Adhesion of microorganisms in the marine environment is essential for initiation and following development of biofouling. A variety of factors play roles in regulating the adhesion. Here we report the influence of Ca(2+) and Mg(2+) in artificial seawater on attachment and colonization of Bacillus sp., Chlorella and Phaeodactylum tricornutum on silicon wafer. Extra addition of the typical divalent cations in culturing solution gives rise to significantly enhanced adhesion of the microorganisms. Mg(2+) and Ca(2+) affect the adhesion of Bacillus sp. presumably by regulating aggregation and formation of extracellular polymeric substances (EPS). The ions alter quantity and types of the proteins in EPS, in turn affecting subsequent adhesion. However, it is noted that Mg(2+) promotes adhesion of Chlorella likely by regulating EPS formation and polysaccharide synthesis. Ca(2+) plays an important role in protein expression to enhance the adhesion of Chlorella. For Phaeodactylum tricornutum, Ca(2+) expedites protein synthesis for enhanced adhesion. The results shed some light on effective ways of utilizing divalent cations to mediate formation of biofilms on the marine structures for desired performances. PMID:27362920

  5. Monodispersed bimetallic PdAg nanoparticles with twinned structures: Formation and enhancement for the methanol oxidation

    Zhen Yin; Yining Zhang; Kai Chen; Jing Li; Wenjing Li; Pei Tang; Huabo Zhao; Qingjun Zhu; Xinhe Bao; Ding Ma

    2014-01-01

    Monodispersed bimetallic PdAg nanoparticles can be fabricated through the emulsion-assisted ethylene glycol (EG) ternary system. Different compositions of bimetallic PdAg nanoparticles, Pd80Ag20, Pd65Ag35 and Pd46Ag54 can be obtained via adjusting the reaction parameters. For the formation process of the bimetallic PdAg nanoparticles, there have two-stage growth processes: firstly, nucleation and growth of the primary nanoclusters; secondly, formation of the secondary nanoparticles with the s...

  6. STUDY ON INVITRO PERMEATION ENHANCEMENT OF KETOPROFEN BY FORMATION OF SOLID DISPERSION

    Saleem M.A; Singh Vishal Kumar; Khalid S; Pange Sudhir; Ahnaf Omair

    2011-01-01

    Solid dispersions of ketoprofen were prepared by using different water soluble carriers like β-cyclodextrin, PEG 6000, polyvinyl pyrolidone and urea in appropriate concentration to enhance the transdermal flux. The prepared solid dispersions were characterized by IR spectroscopy & DSC suggested no interaction of drug with carriers. The solid dispersions were evaluated for solubility, Invitro dissolution and Invitro permeation through rat skin. The solubility of ketoprofen was enhanced 3-7 tim...

  7. Enhanced formation of disinfection byproducts in shale gas wastewater-impacted drinking water supplies.

    Parker, Kimberly M; Zeng, Teng; Harkness, Jennifer; Vengosh, Avner; Mitch, William A

    2014-10-01

    The disposal and leaks of hydraulic fracturing wastewater (HFW) to the environment pose human health risks. Since HFW is typically characterized by elevated salinity, concerns have been raised whether the high bromide and iodide in HFW may promote the formation of disinfection byproducts (DBPs) and alter their speciation to more toxic brominated and iodinated analogues. This study evaluated the minimum volume percentage of two Marcellus Shale and one Fayetteville Shale HFWs diluted by fresh water collected from the Ohio and Allegheny Rivers that would generate and/or alter the formation and speciation of DBPs following chlorination, chloramination, and ozonation treatments of the blended solutions. During chlorination, dilutions as low as 0.01% HFW altered the speciation toward formation of brominated and iodinated trihalomethanes (THMs) and brominated haloacetonitriles (HANs), and dilutions as low as 0.03% increased the overall formation of both compound classes. The increase in bromide concentration associated with 0.01-0.03% contribution of Marcellus HFW (a range of 70-200 μg/L for HFW with bromide = 600 mg/L) mimics the increased bromide levels observed in western Pennsylvanian surface waters following the Marcellus Shale gas production boom. Chloramination reduced HAN and regulated THM formation; however, iodinated trihalomethane formation was observed at lower pH. For municipal wastewater-impacted river water, the presence of 0.1% HFW increased the formation of N-nitrosodimethylamine (NDMA) during chloramination, particularly for the high iodide (54 ppm) Fayetteville Shale HFW. Finally, ozonation of 0.01-0.03% HFW-impacted river water resulted in significant increases in bromate formation. The results suggest that total elimination of HFW discharge and/or installation of halide-specific removal techniques in centralized brine treatment facilities may be a better strategy to mitigate impacts on downstream drinking water treatment plants than altering

  8. Enhanced modification of tungsten surface by nanostructure formation during high flux deuterium plasma exposure

    Xu, H.Y. [Key Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang, Sichuan 621907 (China); Luo, G.N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Schut, H. [Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Yuan, Y.; Fu, B.Q.; Godfrey, A. [Key Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, W., E-mail: liuw@mail.tsinghua.edu.cn [Key Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Temmerman, G.De. [FOM Institute DIFFER – Dutch Institute for Fundamental Energy Research, Trilateral Euregio Cluster, Edisonbaan 14, 3439 MN Nieuwegein (Netherlands)

    2014-04-01

    The morphology changes induced by low energy deuterium ions on tungsten surfaces is studied for particle fluxes similar to those expected in the ITER divertor, as high as 10{sup 24} m{sup −2} s{sup −1}. A new type of surface modifications by formation of nanostructures is observed to occur under those conditions. The nanostructures formation is critically dependent on the particle flux and ion energy, and affected by surface temperature and particle fluence. It correlates with the formation of nano-cavities at a depth of about 40 nm below the surface. In addition, the positron annihilation Doppler broadening (PADB) measurements reveal a significant increase of defect concentration (mostly vacancy-type) after plasma exposure, and the evolution of defects is in line with the surface morphology changes with fluence and surface temperature. The possible mechanism of cyclic trap mutation and dislocation loop punching due to high flux D exposure is discussed.

  9. Enhanced modification of tungsten surface by nanostructure formation during high flux deuterium plasma exposure

    Xu, H. Y.; Luo, G. N.; Schut, H.; Yuan, Y.; Fu, B. Q.; Godfrey, A.; Liu, W.; Temmerman, G. De.

    2014-04-01

    The morphology changes induced by low energy deuterium ions on tungsten surfaces is studied for particle fluxes similar to those expected in the ITER divertor, as high as 1024 m-2 s-1. A new type of surface modifications by formation of nanostructures is observed to occur under those conditions. The nanostructures formation is critically dependent on the particle flux and ion energy, and affected by surface temperature and particle fluence. It correlates with the formation of nano-cavities at a depth of about 40 nm below the surface. In addition, the positron annihilation Doppler broadening (PADB) measurements reveal a significant increase of defect concentration (mostly vacancy-type) after plasma exposure, and the evolution of defects is in line with the surface morphology changes with fluence and surface temperature. The possible mechanism of cyclic trap mutation and dislocation loop punching due to high flux D exposure is discussed.

  10. FORMATION OF CARBON-ENHANCED METAL-POOR STARS IN THE PRESENCE OF FAR-ULTRAVIOLET RADIATION

    Recent discoveries of carbon-enhanced metal-poor stars like SMSS J031300.36–670839.3 provide increasing observational insights into the formation conditions of the first second-generation stars in the universe, reflecting the chemical conditions after the first supernova explosion. Here, we present the first cosmological simulations with a detailed chemical network including primordial species as well as C, C+, O, O+, Si, Si+, and Si2+ following the formation of carbon-enhanced metal-poor stars. The presence of background UV flux delays the collapse from z = 21 to z = 15 and cool the gas down to the cosmic microwave background temperature for a metallicity of Z/Z ☉ = 10–3. This can potentially lead to the formation of lower-mass stars. Overall, we find that the metals have a stronger effect on the collapse than the radiation, yielding a comparable thermal structure for large variations in the radiative background. We further find that radiative backgrounds are not able to delay the collapse for Z/Z ☉ = 10–2 or a carbon abundance as in SMSS J031300.36–670839.3

  11. Red mud (RM)-Induced enhancement of iron plaque formation reduces arsenic and metal accumulation in two wetland plant species.

    Yang, J X; Guo, Q J; Yang, J; Zhou, X Y; Ren, H Y; Zhang, H Z; Xu, R X; Wang, X D; Peters, M; Zhu, G X; Wei, R F; Tian, L Y; Han, X K

    2016-01-01

    Human activities have resulted in arsenic (As) and heavy metals accumulation in paddy soils in China. Phytoremediation has been suggested as an effective and low-cost method to clean up contaminated soils. A combined soil-sand pot experiment was conducted to investigate the influence of red mud (RM) supply on iron plaque formation and As and heavy metal accumulation in two wetland plant species (Cyperus alternifolius Rottb., Echinodorus amazonicus Rataj), using As and heavy metals polluted paddy soil combined with three rates of RM application (0, 2%, 5%). The results showed that RM supply significantly decreased As and heavy metals accumulation in shoots of the two plants due to the decrease of As and heavy metal availability and the enhancement of the formation of iron plaque on the root surface and in the rhizosphere. Both wetland plants supplied with RM tended to have more Fe plaque, higher As and heavy metals on roots and in their rhizospheres, and were more tolerant of As and heavy metal toxicity. The results suggest that RM-induced enhancement of the formation of iron plaque on the root surface and in the rhizosphere of wetland plants may be significant for remediation of soils contaminated with As and heavy metals. PMID:26505322

  12. FORMATION OF CARBON-ENHANCED METAL-POOR STARS IN THE PRESENCE OF FAR-ULTRAVIOLET RADIATION

    Bovino, S.; Schleicher, D. R. G.; Latif, M. A. [Institut für Astrophysik Georg-August-Universität, Friedrich-Hund Platz 1, 37077 Göttingen (Germany); Grassi, T., E-mail: sbovino@astro.physik.uni-goettingen.de [Centre for Star and Planet Formation, Natural History Museum of Denmark, Øster Voldgade 5-7, 1350 Copenhagen (Denmark)

    2014-08-01

    Recent discoveries of carbon-enhanced metal-poor stars like SMSS J031300.36–670839.3 provide increasing observational insights into the formation conditions of the first second-generation stars in the universe, reflecting the chemical conditions after the first supernova explosion. Here, we present the first cosmological simulations with a detailed chemical network including primordial species as well as C, C{sup +}, O, O{sup +}, Si, Si{sup +}, and Si{sup 2+} following the formation of carbon-enhanced metal-poor stars. The presence of background UV flux delays the collapse from z = 21 to z = 15 and cool the gas down to the cosmic microwave background temperature for a metallicity of Z/Z {sub ☉} = 10{sup –3}. This can potentially lead to the formation of lower-mass stars. Overall, we find that the metals have a stronger effect on the collapse than the radiation, yielding a comparable thermal structure for large variations in the radiative background. We further find that radiative backgrounds are not able to delay the collapse for Z/Z {sub ☉} = 10{sup –2} or a carbon abundance as in SMSS J031300.36–670839.3.

  13. TOL Plasmid Carriage Enhances Biofilm Formation and Increases Extracellular DNA Content in Pseudomonas Putida KT2440

    Smets, Barth F.; D'Alvise, Paul; Yankelovich, T.; Sjøholm, O.; Jin, Y.; Wuertz, S.

    Adherent growth of Pseudomonas putida KT2440 with and without the TOL plasmid (pWWO) at the solid-liquid and air-liquid interface was examined. We compared biofilm formation on glass in flow cells, and assayed pellicle (air-liquid interface biofilm) formation in stagnant liquid cultures by confocal...... laser scanning microscopy. The TOL-carrying strains formed pellicles and thick biofilms, whereas the same strains without the plasmid displayed little adherent growth. Microscopy using fluorescent nucleic acid- specific stains (cytox orange, propidium iodide) revealed differences in production of...

  14. Dramatic enhancement of fullerene anion formation in polymer solar cells by thermal annealing: Direct observation by electron spin resonance

    Using electron spin resonance (ESR), we clarified the origin of the efficiency degradation of polymer solar cells containing a lithium-fluoride (LiF) buffer layer created by a thermal annealing process after the deposition of an Al electrode (post-annealing). The device structure was indium-tin-oxide/ poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate)/poly (3-hexylthiophene):phenyl-C61-butyric acid methyl ester (P3HT:PCBM)/LiF/Al. Three samples consisting of quartz/P3HT:PCBM/LiF/Al, quartz/P3HT:PCBM/Al, and quartz/PCBM/LiF/Al were investigated and compared. A clear ESR signal from radical anions on the PCBM was observed after LiF/Al was deposited onto a P3HT:PCBM layer because of charge transfer at the interface between the PCBM and the LiF/Al, which indicated the formation of PCBM−Li+ complexes. The number of radical anions on the PCBM was enhanced remarkably by the post-annealing process; this enhancement was caused by the surface segregation of PCBM and by the dissociation of LiF at the Al interface by the post-annealing process. The formation of a greater number of anions enhanced the electron scattering, decreased the electron-transport properties of the PCBM molecules, and caused an energy-level shift at the interface. These effects led to degradation in the device performance.

  15. Learning Styles and Formative Assessment Strategy: Enhancing Student Achievement in Web-Based Learning

    Wang, K. H.; Wang, T. H.; Wang, W. L.; Huang, S. C.

    2006-01-01

    The purpose of this research was to investigate the effects of formative assessment and learning style on student achievement in a Web-based learning environment. A quasi-experimental research design was used. Participants were 455 seventh grade students from 12 classes of six junior high schools. A Web-based course, named BioCAL, combining three…

  16. Enhancing the Impact of Formative Feedback on Student Learning through an Online Feedback System

    Hatziapostolou, Thanos; Paraskakis, Iraklis

    2010-01-01

    Formative feedback is instrumental in the learning experience of a student. It can be effective in promoting learning if it is timely, personal, manageable, motivational, and in direct relation with assessment criteria. Despite its importance, however, research suggests that students are discouraged from engaging in the feedback process primarily…

  17. Enhancing Research and Practice in Early Childhood through Formative and Design Experiments

    Bradley, Barbara A.; Reinking, David

    2011-01-01

    This article describes formative and design experiments and how they can advance research and instructional practices in early childhood education. We argue that this relatively new approach to education research closes the gap between research and practice, and it addresses limitations that have been identified in early childhood research. We…

  18. Information Literacy Follow-Through: Enhancing Preservice Teachers' Information Evaluation Skills through Formative Assessment

    Seely, Sara Robertson; Fry, Sara Winstead; Ruppel, Margie

    2011-01-01

    An investigation into preservice teachers' information evaluation skills at a large university suggests that formative assessment can improve student achievement. Preservice teachers were asked to apply information evaluation skills in the areas of currency, relevancy, authority, accuracy, and purpose. The study used quantitative methods to assess…

  19. Formation of host-guest complexes on gold surface investigated by surface-enhanced IR absorption spectroscopy

    Inokuchi, Yoshiya; Mizuuchi, Takahiro; Ebata, Takayuki; Ikeda, Toshiaki; Haino, Takeharu; Kimura, Tetsunari; Guo, Hao; Furutani, Yuji

    2014-01-01

    We apply surface-enhanced infrared absorption (SEIRA) spectroscopy to host-guest complexes in liquid phase to examine the structural change in the complex formation. Two thiol derivatives of 18-crown-6 (18C6) are chemisorbed on a gold surface, and aqueous solutions of MCl salts (M = Li, Na, K, Rb, and Cs) are put to form M+·18C6 complexes. Infrared spectra of these complexes in the 900-2000 cm-1 region are obtained by SEIRA spectroscopy. The observed IR spectra show noticeable peaks due to the complex formation, demonstrating that SEIRA spectroscopy will be a powerful method to investigate the structure of host-guest complexes in supramolecular chemistry.

  20. Multinuclear giant cell formation is enhanced by down-regulation of Wnt signaling in gastric cancer cell line, AGS

    AGS cells, which were derived from malignant gastric adenocarcinoma tissue, lack E-cadherin-mediated cell adhesion but have a high level of nuclear β-catenin, which suggests altered Wnt signal. In addition, approximately 5% of AGS cells form multinuclear giant cells in the routine culture conditions, while taxol treatment causes most AGS cells to become giant cells. The observation of reduced nuclear β-catenin levels in giant cells induced by taxol treatment prompted us to investigate the relationship between Wnt signaling and giant cell formation. After overnight serum starvation, the shape of AGS cells became flattened, and this morphological change was accompanied by decrease in Myc expression and an increase in the giant cell population. Lithium chloride treatment, which inhibits GSK3β activity, reversed these serum starvation effects, which suggests an inverse relationship between Wnt signaling and giant cell formation. Furthermore, the down-regulation of Wnt signaling caused by the over-expression of ICAT, E-cadherin, and Axin enhanced giant cell formation. Therefore, down-regulation of Wnt signaling may be related to giant cell formation, which is considered to be a survival mechanism against induced cell death

  1. Galaxy Pairs in the Sloan Digital Sky Survey - X: Does gas content alter star formation rate enhancement in galaxy interactions?

    Scudder, Jillian M; Momjian, Emmanuel; Rosenberg, Jessica L; Torrey, Paul; Patton, David R; Mendel, J Trevor

    2015-01-01

    New spectral line observations, obtained with the Jansky Very Large Array (VLA), of a sample of 34 galaxies in 17 close pairs are presented in this paper. The sample of galaxy pairs is selected to contain galaxies in close, major interactions (i.e., projected separations $ 3\\sigma$. We compare the HI gas fraction of the galaxies with the triggered star formation present in that galaxy. When compared to the star formation rates (SFRs) of non-pair galaxies matched in mass, redshift, and local environment, we find that the star formation enhancement is weakly positively correlated ($\\sim 2.5\\sigma$) with HI gas fraction. In order to help understand the physical mechanisms driving this weak correlation, we also present results from a small suite of binary galaxy merger simulations with varying gas fractions. The simulated galaxies indicate that larger initial gas fractions are associated with lower levels of interaction-triggered star formation (relative to an identical galaxy in isolation), but also show that hi...

  2. Formation of host–guest complexes on gold surface investigated by surface-enhanced IR absorption spectroscopy

    Inokuchi, Yoshiya; Mizuuchi, Takahiro; Ebata, Takayuki; Ikeda, Toshiaki; Haino, Takeharu; Kimura, Tetsunari; Guo, Hao; Furutani, Yuji

    2014-01-01

    We apply surface-enhanced infrared absorption (SEIRA) spectroscopy to host-guest complexes in liquid phase to examine the structural change in the complex formation. Two thiol derivatives of 18-crown-6 (18C6) are chemisorbed on a gold surface, and aqueous solutions of MCl salts (M = Li, Na, K, Rb, and Cs) are put to form M+・18C6 complexes. Infrared spectra of these complexes in the 900-2000 cm-1 region are obtained by SEIRA spectroscopy. The observed IR spectra show noticeable peaks due to th...

  3. Single-field inflation, anomalous enhancement of superhorizon fluctuations and non-Gaussianity in primordial black hole formation

    We show a textbook potential for single-field inflation, namely the Coleman–Weinberg model can induce double inflation and formation of primordial black holes (PBHs), because fluctuations that leave the horizon near the end of first inflation are anomalously enhanced at the onset of second inflation when the time-dependent mode turns into a growing mode rather than a decaying mode. The mass of PBHs produced in this mechanism with an appreciable density are distributed at certain intervals depending on the model parameters. We also calculate the effects of non-Gaussian statistics due to higher-order interactions on the abundance of PBHs, which turns out to be small

  4. Electrolytic Formation of Crystalline Silicon/Germanium Alloy Nanotubes and Hollow Particles with Enhanced Lithium-Storage Properties.

    Xiao, Wei; Zhou, Jing; Yu, Le; Wang, Dihua; Lou, Xiong Wen David

    2016-06-20

    Crystalline silicon(Si)/germanium(Ge) alloy nanotubes and hollow particles are synthesized for the first time through a one-pot electrolytic process. The morphology of these alloy structures can be easily tailored from nanotubes to hollow particles by varying the overpotential during the electro-reduction reaction. The continuous solid diffusion governed by the nanoscale Kirkendall effect results in the formation of inner void in the alloy particles. Benefitting from the compositional and structural advantages, these SiGe alloy nanotubes exhibit much enhanced lithium-storage performance compared with the individual solid Si and Ge nanowires as the anode material for lithium-ion batteries. PMID:27159140

  5. Angiogenic factor-enriched platelet-rich plasma enhances in vivo bone formation around alloplastic graft material

    Kim, Eun-Seok; Kim, Jae-Jin; Park, Eun-Jin

    2010-01-01

    PURPOSE Although most researchers agree that platelet-rich plasma (PRP) is a good source of autogenous growth factors, its effect on bone regeneration is still controversial. The purpose of this study was to evaluate whether increasing angiogenic factors in the human PRP to enhance new bone formation through rapid angiogenesis. MATERIAL AND METHODS In vitro, the human platelets were activated with application of shear stress, 20 µg/ml collagen, 2 mM CaCl2 and 10U thrombin/1 × 109 platelets. L...

  6. Estradiol replacement enhances fear memory formation, impairs extinction and reduces COMT expression levels in the hippocampus of ovariectomized female mice.

    McDermott, Carmel M; Liu, Dan; Ade, Catherine; Schrader, Laura A

    2015-02-01

    Females experience depression, posttraumatic stress disorder (PTSD), and anxiety disorders at approximately twice the rate of males, but the mechanisms underlying this difference remain undefined. The effect of sex hormones on neural substrates presents a possible mechanism. We investigated the effect of ovariectomy at two ages, before puberty and in adulthood, and 17β-estradiol (E2) replacement administered chronically in drinking water on anxiety level, fear memory formation, and extinction. Based on previous studies, we hypothesized that estradiol replacement would impair fear memory formation and enhance extinction rate. Females, age 4 weeks and 10 weeks, were divided randomly into 4 groups; sham surgery, OVX, OVX+low E2 (200nM), and OVX+high E2 (1000nM). Chronic treatment with high levels of E2 significantly increased anxiety levels measured in the elevated plus maze. In both age groups, high levels of E2 significantly increased contextual fear memory but had no effect on cued fear memory. In addition, high E2 decreased the rate of extinction in both ages. Finally, catechol-O-methyltransferase (COMT) is important for regulation of catecholamine levels, which play a role in fear memory formation and extinction. COMT expression in the hippocampus was significantly reduced by high E2 replacement, implying increased catecholamine levels in the hippocampus of high E2 mice. These results suggest that estradiol enhanced fear memory formation, and inhibited fear memory extinction, possibly stabilizing the fear memory in female mice. This study has implications for a neurobiological mechanism for PTSD and anxiety disorders. PMID:25555360

  7. Hydrogen enhanced thermal donor formation in oxygen enriched high resistive float-zone silicon

    Hydrogen supported thermal donor (TD) formation was observed in oxygen enriched high resistive float zone (FZ) silicon being used as substrates for detectors in the Large Hadron Collider (CERN). TD formation was provided by a '2-step-process', consisting of a plasma hydrogenation at 250 deg. C (60 min) and subsequent annealing at 450 deg. C in air (typically for 20-30 min). The samples were analyzed by spreading resistance probe (SRP), C(V) and DLTS measurements. Doping by TDs in the oxygen enriched layers of FZ Si samples might be a promising method for the creation of very deep (∼100 μm) electrical field gradients for an improved performance of Si radiation detectors

  8. Enhancement of TFO Triplex Formation by Conjugation with Pyrene via Click Chemistry.

    Taniguchi, Yosuke; Tomizaki, Akira; Matsueda, Nozomu; Okamura, Hidenori; Sasaki, Shigeki

    2015-01-01

    This paper reports the preparation of 14-mer triplex-forming oligonucleotides (TFOs) containing a 2-O-methyl-1-β-phenyl-α-propargyl-ribose unit, which was conjugated with azide-modified molecules via a click reaction. Modification of these TFOs with pyrene assisted triplex formation, improving the stability of the triplex DNA and the anti-proliferative effects against A549 cells. PMID:26521856

  9. Loss of p53 enhances NF-κB-dependent lamellipodia formation.

    Guo, Alvin Kunyao; Hou, Yan Yan; Hirata, Hiroaki; Yamauchi, Shota; Yip, Ai Kia; Chiam, Keng-Hwee; Tanaka, Nobuyuki; Sawada, Yasuhiro; Kawauchi, Keiko

    2014-06-01

    Tumor suppressor p53 prevents tumorigenesis and tumor growth by suppressing the activation of several transcription factors, including nuclear factor-κB (NF-κB) and STAT3. On the other hand, p53 stimulates actin cytoskeleton remodeling and integrin-related signaling cascades. Here, we examined the p53-mediated link between regulation of the actin cytoskeleton and activation of NF-κB and STAT3 in MCF-7 cells and mouse embryonic fibroblasts (MEFs). In the absence of p53, STAT3 was constitutively activated. This activation was attenuated by depleting the expression of p65, a component of NF-κB. Integrin β3 expression and lamellipodia formation were also downregulated by NF-κB depletion. Inhibition of integrin αvβ3, Rac1 or Arp2/3, which diminished lamellipodia formation, suppressed STAT3 activation induced by p53 depletion. These results suggest that loss of p53 leads to STAT3 activation via NF-κB-dependent lamellipodia formation. Our study proposes a novel role for p53 in modulating the actin cytoskeleton through suppression of NF-κB, which restricts STAT3 activation. PMID:24647813

  10. Enhanced formation of thermal donors in irradiated germanium: local vibrational mode spectroscopy

    Oxygen-rich Ge samples were irradiated with fast electrons (E = 4 MeV) at 80 deg C and subjected to isochronal (100-340 deg C) and isothermal (350 deg C) annealings. Infra-red absorption spectra were measured at room temperature. Preliminary irradiation is found to enhance strongly the development of the absorption bands in the range 600 and 780 cm-1 upon heating the Ge crystals at 350 deg C. The bands are assigned to local vibrational modes (LVM) of thermal donors (TD). It is inferred from the annealing studies that a radiation-induced complex with the LVM at about 770-780 cm-1 is likely responsible for the enhanced growth of TD. The oxygen dimer is suggested to be such a complex

  11. in Situ Formation of a Biocatalytic Alginate Membrane by Enhanced Concentration Polarization

    Marpani, Fauziah; Luo, Jianquan; Mateiu, Ramona Valentina; Meyer, Anne S.; Pinelo, Manuel

    2015-01-01

    A thin alginate layer induced on the surface of a commercial polysulfone membrane was used as a matrix for noncovalent immobilization of enzymes. Despite the expected decrease of flux across the membrane resulting from the coating, the initial hypothesis was that such a system should allow high i...... consequence on the type of immobilization promoted in each phase. The results suggested that the strategy proposed could be efficiently used to enhance the enzyme loading on polymer membranes....

  12. Motor Skills Enhance Procedural Memory Formation and Protect against Age-Related Decline

    Müller, Nils C. J.; Genzel, Lisa; Konrad, Boris N.; Pawlowski, Marcel; Neville, David; Fernández, Guillén; Steiger, Axel

    2016-01-01

    The ability to consolidate procedural memories declines with increasing age. Prior knowledge enhances learning and memory consolidation of novel but related information in various domains. Here, we present evidence that prior motor experience–in our case piano skills–increases procedural learning and has a protective effect against age-related decline for the consolidation of novel but related manual movements. In our main experiment, we tested 128 participants with a sequential finger-tapping motor task during two sessions 24 hours apart. We observed enhanced online learning speed and offline memory consolidation for piano players. Enhanced memory consolidation was driven by a strong effect in older participants, whereas younger participants did not benefit significantly from prior piano experience. In a follow up independent control experiment, this compensatory effect of piano experience was not visible after a brief offline period of 30 minutes, hence requiring an extended consolidation window potentially involving sleep. Through a further control experiment, we rejected the possibility that the decreased effect in younger participants was caused by training saturation. We discuss our results in the context of the neurobiological schema approach and suggest that prior experience has the potential to rescue memory consolidation from age-related cognitive decline. PMID:27333186

  13. A potential cause for kidney stone formation during space flights: enhanced growth of nanobacteria in microgravity

    Ciftcioglu, Neva; Haddad, Ruwaida S.; Golden, D. C.; Morrison, Dennis R.; McKay, David S.

    2005-01-01

    BACKGROUND: Although some information is available regarding the cellular/molecular changes in immune system exposed to microgravity, little is known about the reasons of the increase in the kidney stone formation in astronauts during and/or after long duration missions at zero gravity (0 g). In our earlier studies, we have assessed a unique agent, nanobacteria (NB), in kidney stones and hypothesized that NB have an active role in calcium phosphate-carbonate deposition in kidney. In this research we studied effect of microgravity on multiplication and calcification of NB in vitro. METHODS: We examined NB cultures in High Aspect Rotating Vessels (HARVs) designed at the NASA's Johnson Space Center, which are designed to stimulate some aspects of microgravity. Multiplication rate and calcium phosphate composition of those NB were compared with NB cultured on stationary and shaker flasks. Collected aliquots of the cultures from different incubation periods were analyzed using spectrophotometer, SEM, TEM, EDX, and x-ray diffraction techniques. RESULTS: The results showed that NB multiplied 4.6x faster in HARVs compared to stationary cultures, and 3.2x faster than shaker flask conditions. X-ray diffraction and EDX analysis showed that the degree of apatite crystal formation and the properties of the apatite depend on the specific culture conditions used. CONCLUSION: We now report an increased multiplication rate of NB in microgravity-simulated conditions. Thus, NB infection may have a potential role in kidney stone formation in crew members during space flights. For further proof to this hypothesis, screening of the NB antigen and antibody level in flight crew before and after flight would be necessary.

  14. Enhanced High Temperature Corrosion Resistance in Advanced Fossil Energy Systems by Nano-Passive Layer Formation

    Arnold R. Marder

    2007-06-14

    Due to their excellent corrosion resistance, iron aluminum alloys are currently being considered for use as weld claddings in fossil fuel fired power plants. The susceptibility to hydrogen cracking of these alloys at higher aluminum concentrations has highlighted the need for research into the effect of chromium additions on the corrosion resistance of lower aluminum alloys. In the present work, three iron aluminum alloys were exposed to simulated coal combustion environments at 500 C and 700 C for both short (100 hours) and long (5,000 hours) isothermal durations. Scanning electron microscopy was used to analyze the corrosion products. All alloys exhibited excellent corrosion resistance in the short term tests. For longer exposures, increasing the aluminum concentration was beneficial to the corrosion resistance. The addition of chromium to the binary iron aluminum alloy prevented the formation iron sulfide and resulted in lower corrosion kinetics. A classification of the corrosion products that developed on these alloys is presented. Scanning transmission electron microscopy (STEM) of the as-corroded coupons revealed that chromium was able to form chromium sulfides only on the higher aluminum alloy, thereby preventing the formation of deleterious iron sulfides. When the aluminum concentration was too low to permit selective oxidation of only aluminum (upon initial exposure to the corrosion environment), the formation of chromium oxide alongside the aluminum oxide led to depletion of chromium beneath the oxide layer. Upon penetration of sulfur through the oxide into this depletion layer, iron sulfides (rather than chromium sulfides) were found to form on the low aluminum alloy. Thus, it was found in this work that the role of chromium on alloy corrosion resistance was strongly effected by the aluminum concentration of the alloy. STEM analysis also revealed the encapsulation of external iron sulfide products with a thin layer of aluminum oxide, which may provide a

  15. Muramyl Dipeptide Enhances Lipopolysaccharide-Induced Osteoclast Formation and Bone Resorption through Increased RANKL Expression in Stromal Cells

    Masahiko Ishida

    2015-01-01

    Full Text Available Lipopolysaccharide (LPS is bacterial cell wall component capable of inducing osteoclast formation and pathological bone resorption. Muramyl dipeptide (MDP, the minimal essential structural unit responsible for the immunological activity of peptidoglycans, is ubiquitously expressed by bacterium. In this study, we investigated the effect of MDP in LPS-induced osteoclast formation and bone resorption. LPS was administered with or without MDP into the supracalvariae of mice. The number of osteoclasts, the level of mRNA for cathepsin K and tartrate-resistant acid phosphatase (TRAP, the ratio of the bone destruction area, the level of tartrate-resistant acid phosphatase form 5b (TRACP 5b, and C-terminal telopeptides fragments of type I collagen as a marker of bone resorption in mice administrated both LPS and MDP were higher than those in mice administrated LPS or MDP alone. On the other hand, MDP had no effect on osteoclastogenesis in parathyroid hormone administrated mice. MDP enhanced LPS-induced receptor activator of NF-κB ligand (RANKL expression and Toll-like receptor 4 (TLR4 expression in vivo and in stromal cells in vitro. MDP also enhanced LPS-induced mitogen-activated protein kinase (MAPK signaling, including ERK, p38, and JNK, in stromal cells. These results suggest that MDP might play an important role in pathological bone resorption in bacterial infection diseases.

  16. Enhanced lattice defect formation associated with hydrogen and hydrogen embrittlement under elastic stress of a tempered martensitic steel

    Hydrogen behavior and hydrogen-enhanced lattice defect formation under elastic stress of tempered martensitic steel were clarified with respect to dislocations and vacancies by thermal desorption analysis (TDA) using hydrogen as a probe of defects and a positron probe microanalyzer (PPMA). The relationship between hydrogen embrittlement and lattice defects associated with hydrogen was also investigated. The amount of lattice defects increased gradually with increasing time of applied stress during hydrogen charging. The specimen fractured under elastic stress in the presence of hydrogen macroscopically showed brittle fracture without necking. Whereas fracture surface was attributed to localized plastic deformation, since the morphology of the microscopic fracture surface was mostly quasi-cleavage fracture. The increased lattice defects in the near-fracture area were subsequently removed by annealing at 200degC. The mean positron annihilation lifetime measured with the PPMA for a fractured specimen was longer in the near-fracture area than in other areas. Thus, the most probable reason for the increase in the amount of lattice defects can be ascribed to an increase in the amount of vacancies or vacancy clusters. Regarding hydrogen embrittlement involving microscopic plastic deformation, the localized enhanced vacancies due to interactions between dislocations and hydrogen under elastic stress directly caused ductility loss, because ductility loss occurred even though hydrogen was completely removed by degassing before the tensile test. Besides hydrogen content and applied stress, the time of formation and accumulation of vacancies are also concluded to be important factors causing hydrogen embrittlement. (author)

  17. Anomalous Photofragmentation of Fullerene Doped in Silica Aerogel-Enhanced Formation of Odd-Numbered "Fullerene" Fragments

    孔庆宇; 赵利; 庄军; 钱士雄; 李郁芬; 王钰

    2001-01-01

    Photofragmentation of fullerene-doped silica aerogels has been investigated by the excimer laser ablation reflectron time-of-flight mass spectrometric technique. Great enhancement in the formation of odd-numbered 'fullerene' fragments has been observed in the negative-ion channel for the chemically doped aerogel sample. Generally, oddnumbered species C57, C55, C53 and C51 appeared in the mass spectra. Under optimM experimental conditions C55 can be even more intense than the neighbouring even-numbered carbon clusters. In contrast, for the physicallydoped sample, just like pristine C6o, only weak odd-numbered fragments were observed. In the positive-ion channel, the behaviour of all these samples is similar, no odd-numbered species was ever detected. A mechanism related to the interaction between the fullerene dopant and the silica aerogel host is suggested for the anomalous enhancement of the odd-numbered duster formation. A preliminary discussion on the structures of the oddnumbered 'fullerene' fragments is given.

  18. Suppression of transient enhanced diffusion in sub-micron patterned silicon template by dislocation loops formation

    We investigate the evolution of two dimensional transient enhanced diffusion (TED) of phosphorus in sub-micron scale patterned silicon template. Samples doped with low dose phosphorus with and without high dose silicon self-implantation, were annealed for various durations. Dopant diffusion is probed with plane-view scanning capacitance microscopy. The measurement revealed two phases of TED. Significant suppression in the second phase TED is observed for samples with high dose self-implantation. Transmission electron microscopy suggests the suppressed TED is related to the evolution of end of range defect formed around ion implantation sidewalls

  19. The value of using short-format podcasts to enhance learning and teaching

    Catherine Sutton-Brady

    2009-12-01

    Full Text Available This paper presents the findings of a podcasting trial held in 2007–2008 within the Faculty of Economics and Business at the University of Sydney, Australia. The trial investigates the value of using short-format podcasts to support assessment for postgraduate and undergraduate students. A multi-method approach is taken in investigating perceptions of the benefits of podcasting, incorporating surveys, focus groups and interviews. The results show that a majority of students believe they gained learning benefits from the podcasts and appreciated the flexibility of the medium to support their learning, and the lecturers felt the innovation helped diversify their pedagogical approach and support a diverse student population. Three primary conclusions are presented: (1 most students reject the mobile potential of podcasting in favour of their traditional study space at home; (2 what students and lecturers value about this podcasting design overlap; (3 the assessment-focussed, short-format podcast design may be considered a successful podcasting model. The paper finishes by identifying areas for future research on the effective use of podcasting in learning and teaching.

  20. Effect of size of fly ash particle on enhancement of mullite content and glass formation

    Parveen Sultana; Sukhen Das; Biswajoy Bagchi; Alakananda Bhattacharya; Ruma Basu; Papiya Nandy

    2011-12-01

    Quartz is widely replaced by fly ash in traditional porcelain composite. Increased strength and stability of the fly ash-mixed composite depends on the quantity and crystallinity of the mullite phase in the fly ash. Our aim in this investigation is to increase the formation of mullite in nanocrystalline form and study the effect of temperature. Quantitative estimation of mullite and residual quartz content were done by Xray diffraction (XRD) and nanostructure and crystallization were studied using differential thermal analysis (DTA), field effect scanning electron microscopy (FESEM), XRD and Fourier transform infrared (FTIR) spectroscopy. The results show that fly ash sieved through 250 holes/cm2 mesh contain more mullite initially and growth of mullite as well as glass formation was faster in this sample compared to coarse fly ash. The maximum mullite in these samples was formed at 1600°C. Transformation of quartz and cristobalite phases into glassy phase was also faster for smaller particle sizes of fly ash.

  1. Nicotinic α7 and α4β2 agonists enhance the formation and retrieval of recognition memory: Potential mechanisms for cognitive performance enhancement in neurological and psychiatric disorders.

    McLean, Samantha L; Grayson, Ben; Marsh, Samuel; Zarroug, Samah H O; Harte, Michael K; Neill, Jo C

    2016-04-01

    Cholinergic dysfunction has been shown to be central to the pathophysiology of Alzheimer's disease and has also been postulated to contribute to cognitive dysfunction observed in various psychiatric disorders, including schizophrenia. Deficits are found across a number of cognitive domains and in spite of several attempts to develop new therapies, these remain an unmet clinical need. In the current study we investigated the efficacy of donepezil, risperidone and selective nicotinic α7 and α4β2 receptor agonists to reverse a delay-induced deficit in recognition memory. Adult female Hooded Lister rats received drug treatments and were tested in the novel object recognition (NOR) task following a 6h inter-trial interval (ITI). In all treatment groups, there was no preference for the left or right identical objects in the acquisition trial. Risperidone failed to enhance recognition memory in this paradigm whereas donepezil was effective such that rats discriminated between the novel and familiar object in the retention trial following a 6h ITI. Although a narrow dose range of PNU-282987 and RJR-2403 was tested, only one dose of each increased recognition memory, the highest dose of PNU-282987 (10mg/kg) and the lowest dose of RJR-2403 (0.1mg/kg), indicative of enhanced cognitive performance. Interestingly, these compounds were also efficacious when administered either before the acquisition or the retention trial of the task, suggesting an important role for nicotinic receptor subtypes in the formation and retrieval of recognition memory. PMID:26327238

  2. Pharmacological inhibition of lipid droplet formation enhances the effectiveness of curcumin in glioblastoma.

    Zhang, Issan; Cui, Yiming; Amiri, Abdolali; Ding, Yidan; Campbell, Robert E; Maysinger, Dusica

    2016-03-01

    Increased lipid droplet number and fatty acid synthesis allow glioblastoma multiforme, the most common and aggressive type of brain cancer, to withstand accelerated metabolic rates and resist therapeutic treatments. Lipid droplets are postulated to sequester hydrophobic therapeutic agents, thereby reducing drug effectiveness. We hypothesized that the inhibition of lipid droplet accumulation in glioblastoma cells using pyrrolidine-2, a cytoplasmic phospholipase A2 alpha inhibitor, can sensitize cancer cells to the killing effect of curcumin, a promising anticancer agent isolated from the turmeric spice. We observed that curcumin localized in the lipid droplets of human U251N glioblastoma cells. Reduction of lipid droplet number using pyrrolidine-2 drastically enhanced the therapeutic effect of curcumin in both 2D and 3D glioblastoma cell models. The mode of cell death involved was found to be mediated by caspase-3. Comparatively, the current clinical chemotherapeutic standard, temozolomide, was significantly less effective in inducing glioblastoma cell death. Together, our results suggest that the inhibition of lipid droplet accumulation is an effective way to enhance the chemotherapeutic effect of curcumin against glioblastoma multiforme. PMID:26763536

  3. In vitro enhancement of collagen matrix formation and crosslinking for applications in tissue engineering: a preliminary study.

    Lareu, Ricky R; Arsianti, Irma; Subramhanya, Harve Karthik; Yanxian, Peng; Raghunath, Michael

    2007-02-01

    The construction of stable engineered tissue depends on the formation of a functional connective tissue produced by cells locally. A major component of connective tissue is collagen. Its deposition into a stable matrix depends on the enzymatic extracellular conversion of procollagen to collagen. This step is very slow in vitro and we hypothesized that this is due to a lack of crowdedness and insufficient excluded volume effect (EVE) in culture media. We used neutral (670 kDa) and negatively charged dextran sulfate (DxS, 500 kDa) to create EVE in cell cultures and to enhance in vitro matrix formation by accelerating procollagen conversion. Biochemical analyses in 2 human fibroblast lines revealed mostly unprocessed procollagen in uncrowded culture medium, whereas in the presence of DxS, procollagen conversion occurred and most of the collagen was associated with the cell layer. Immunocytochemistry confirmed DxS-related collagen deposition that colocalized with fibronectin. The large neutral dextran showed, in identical concentration ranges, no effects that correlated well with its smaller hydrodynamic radius as determined by dynamic light scattering. This predicted a 10 times bigger crowding power of DxS and benchmarks it as a potentially promising crowding agent facilitating the formation of extracellular matrix in vitro. PMID:17518571

  4. Foliar application of biofilm formation-inhibiting compounds enhances control of citrus canker caused by Xanthomonas citri subsp. citri.

    Li, Jinyun; Wang, Nian

    2014-02-01

    Citrus canker caused by the bacterium Xanthomonas citri subsp. citri is an economically important disease of citrus worldwide. Biofilm formation plays an important role in early infection of X. citri subsp. citri on host leaves. In this study, we assessed the hypothesis that small molecules inhibiting biofilm formation reduce X. citri subsp. citri infection and enhance the control of citrus canker disease. D-leucine and 3-indolylacetonitrile (IAN) were found to prevent biofilm formation by X. citri subsp. citri on different abiotic surfaces and host leaves at a concentration lower than the minimum inhibitory concentration (MIC). Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis indicated that IAN repressed expression of chemotaxis/motility-related genes in X. citri subsp. citri. In laboratory experiments, planktonic and biofilm cells of X. citri subsp. citri treated with D-leucine and IAN, either alone or in combination, were more susceptible to copper (CuSO4) than those untreated. In greenhouse assays, D-leucine and IAN applied alone or combined with copper reduced both the number of canker lesions and bacterial populations of X. citri subsp. citri on citrus host leaves. This study provides the basis for the use of foliar-applied biofilm inhibitors for the control of citrus canker alone or combined with copper-based bactericides. PMID:23901828

  5. Short-term intermittent PTH 1-34 administration enhances bone formation in SCID/Beige mice

    The anabolic effect of intermittent parathyroid hormone (PTH) on bone is variable depending on the species studied, duration/mode of administration, and location of skeletal response investigated. We tested the hypothesis that low dose, short term, intermittent PTH 1-34 administration is sufficient to enhance bone formation without altering bone resorption. To test our hypothesis, mice were treated intermittently with one of three concentrations of PTH 1-34 (1 μg/kg, low; 10μg/kg or 20 μg/kg, high) for three weeks. The skeletal response was identified by quantifying: serum markers of bone turnover, cancellous bone parameters in distal femur, proximal tibia, and lumbar vertebrae by μCT, and number of osteoblasts and osteoclasts in distal femur. Mice receiving 20 μg/kg of PTH 1-34 demonstrated a 30% increase in serum osteocalcin, but no differences in serum calcium, type I collagen teleopeptides, or tartrate resistant acid phosphatase (TRACP) 5b. For all bones, μCT analysis suggested mice receiving 20 μg/kg of PTH 1-34 had increased cancellous bone mineral density, trabecular thickness and spacing, but decreased trabecular number. A 60% increase in the number of alkaline phosphatase positive osteoblasts in the distal femur was also observed in tissue sections; however, the number of TRAP positive osteoclasts was not different between test and control groups. While animals administered 10 μg/kg demonstrated similar trends for all bone turnover indices, such alterations were not observed in animals administered PTH 1-34 at 1 μg/kg per day. Thus, PTH 1-34, administered intermittently for three weeks at 20 μg/kg is sufficient to enhance bone formation without enhancing resorption. (author)

  6. Functionalization with C-terminal cysteine enhances transfection efficiency of cell-penetrating peptides through dimer formation

    Highlights: ► Reversible CPP dimerisation is a simple yet efficient strategy to improve delivery. ► Dimer formation enhances peptiplex stability, resulting in increased transfection. ► By dimerisation, the CPP EB1 even gain endosomal escape properties while lowering cytotoxicity. -- Abstract: Cell-penetrating peptides have the ability to stimulate uptake of macromolecular cargo in mammalian cells in a non-toxic manner and therefore hold promise as efficient and well tolerated gene delivery vectors. Non-covalent peptide-DNA complexes (“peptiplexes”) enter cells via endocytosis, but poor peptiplex stability and endosomal entrapment are considered as main barriers to peptide-mediated delivery. We explore a simple, yet highly efficient, strategy to improve the function of peptide-based vectors, by adding one terminal cysteine residue. This allows the peptide to dimerize by disulfide bond formation, increasing its affinity for nucleic acids by the “chelate effect” and, when the bond is reduced intracellularly, letting the complex dissociate to deliver the nucleic acid. By introducing a single C-terminal cysteine in the classical CPP penetratin and the penetratin analogs PenArg and EB1, we show that this minor modification greatly enhances the transfection capacity for plasmid DNA in HEK293T cells. We conclude that this effect is mainly due to enhanced thermodynamic stability of the peptiplexes as endosome-disruptive chloroquine is still required for transfection and the effect is more pronounced for peptides with lower inherent DNA condensation capacity. Interestingly, for EB1, addition of one cysteine makes the peptide able to mediate transfection in absence of chloroquine, indicating that dimerisation can also improve endosomal escape properties. Further, the cytotoxicity of EB1 peptiplexes is considerably reduced, possibly due to lower concentration of free peptide dimer resulting from its stronger binding to DNA.

  7. Functionalization with C-terminal cysteine enhances transfection efficiency of cell-penetrating peptides through dimer formation

    Amand, Helene L., E-mail: helene.amand@chalmers.se [Chalmers University of Technology, Department of Chemical and Biological Engineering/Physical Chemistry, SE-412 96 Gothenburg (Sweden); Norden, Bengt, E-mail: norden@chalmers.se [Chalmers University of Technology, Department of Chemical and Biological Engineering/Physical Chemistry, SE-412 96 Gothenburg (Sweden); Fant, Kristina, E-mail: kristina.fant@sp.se [Chalmers University of Technology, Department of Chemical and Biological Engineering/Physical Chemistry, SE-412 96 Gothenburg (Sweden)

    2012-02-17

    Highlights: Black-Right-Pointing-Pointer Reversible CPP dimerisation is a simple yet efficient strategy to improve delivery. Black-Right-Pointing-Pointer Dimer formation enhances peptiplex stability, resulting in increased transfection. Black-Right-Pointing-Pointer By dimerisation, the CPP EB1 even gain endosomal escape properties while lowering cytotoxicity. -- Abstract: Cell-penetrating peptides have the ability to stimulate uptake of macromolecular cargo in mammalian cells in a non-toxic manner and therefore hold promise as efficient and well tolerated gene delivery vectors. Non-covalent peptide-DNA complexes ('peptiplexes') enter cells via endocytosis, but poor peptiplex stability and endosomal entrapment are considered as main barriers to peptide-mediated delivery. We explore a simple, yet highly efficient, strategy to improve the function of peptide-based vectors, by adding one terminal cysteine residue. This allows the peptide to dimerize by disulfide bond formation, increasing its affinity for nucleic acids by the 'chelate effect' and, when the bond is reduced intracellularly, letting the complex dissociate to deliver the nucleic acid. By introducing a single C-terminal cysteine in the classical CPP penetratin and the penetratin analogs PenArg and EB1, we show that this minor modification greatly enhances the transfection capacity for plasmid DNA in HEK293T cells. We conclude that this effect is mainly due to enhanced thermodynamic stability of the peptiplexes as endosome-disruptive chloroquine is still required for transfection and the effect is more pronounced for peptides with lower inherent DNA condensation capacity. Interestingly, for EB1, addition of one cysteine makes the peptide able to mediate transfection in absence of chloroquine, indicating that dimerisation can also improve endosomal escape properties. Further, the cytotoxicity of EB1 peptiplexes is considerably reduced, possibly due to lower concentration of free peptide

  8. Depletion of tyrosyl DNA phosphodiesterase 2 activity enhances etoposide-mediated double-strand break formation and cell killing.

    Kont, Yasemin Saygideger; Dutta, Arijit; Mallisetty, Apurva; Mathew, Jeena; Minas, Tsion; Kraus, Christina; Dhopeshwarkar, Priyanka; Kallakury, Bhaskar; Mitra, Sankar; Üren, Aykut; Adhikari, Sanjay

    2016-07-01

    DNA topoisomerase 2 (Top2) poisons, including common anticancer drugs etoposide and doxorubicin kill cancer cells by stabilizing covalent Top2-tyrosyl-DNA 5'-phosphodiester adducts and DNA double-strand breaks (DSBs). Proteolytic degradation of the covalently attached Top2 leaves a 5'-tyrosylated blocked termini which is removed by tyrosyl DNA phosphodiesterase 2 (TDP2), prior to DSB repair through non-homologous end joining (NHEJ). Thus, TDP2 confers resistance of tumor cells to Top2-poisons by repairing such covalent DNA-protein adducts, and its pharmacological inhibition could enhance the efficacy of Top2-poisons. We discovered NSC111041, a selective inhibitor of TDP2, by optimizing a high throughput screening (HTS) assay for TDP2's 5'-tyrosyl phosphodiesterase activity and subsequent validation studies. We found that NSC111041 inhibits TDP2's binding to DNA without getting intercalated into DNA and enhanced etoposide's cytotoxicity synergistically in TDP2-expressing cells but not in TDP2 depleted cells. Furthermore, NSC111041 enhanced formation of etoposide-induced γ-H2AX foci presumably by affecting DSB repair. Immuno-histochemical analysis showed higher TDP2 expression in a sub-set of different type of tumor tissues. These findings underscore the feasibility of clinical use of suitable TDP2 inhibitors in adjuvant therapy with Top2-poisons for a sub-set of cancer patients with high TDP2 expression. PMID:27235629

  9. ICP-Enhanced Sputter Deposition for Reactivity Control and Low-Temperature Formation of a-IGZO Films

    Setsuhara, Yuichi; Nakata, Keitaro; Satake, Yoshikatsu; Takenaka, Kosuke; Uchida, Giichiro; Ebe, Akinori

    2015-09-01

    Inductively coupled plasma (ICP) - enhanced sputter deposition for a-IGZO channel TFTs fabrication have been performed. This advantage of fine control of reactivity during the deposition process is of great significance for film deposition of the transparent amorphous oxide semiconductor, a-InGaZnOx (a-IGZO), whose electrical properties are significantly sensitive to the reactivity during the film deposition. The a-IGZO film deposition with addition of H2 gas were performed in order to control oxidation process during a-IGZO film formation via balance between oxidation-reduction. The results of optical emission spectrum indicate the possibility for the suppression of oxidation by oxygen atoms of a-IGZO films during deposition due to addition of H2 gas. The characteristics of TFT fabricated with IGZO film via plasma-enhanced magnetron sputter deposition system have been investigated. The result exhibits that the possibility of expanding process window for control of balance between oxidization and reduction by addition of H2 gas. The a-IGZO channel TFTs fabricated plasma-enhanced reactive sputtering system with addition of H2 gas exhibited good performance of field-effect mobility 15.3 cm2(Vs)-1 and subthreshold gate voltage swing (S) of 0.48 V decade-1. This work was partly supported by ASTEP (JST) and Grant-in-Aid for Challenging Exploratory Research (JSPS).

  10. Formation of salbutamol sulphate microparticles using solution enhanced dispersion by supercritical carbon dioxide

    Abdolhossein Rouholamini Najafabadi

    2005-01-01

    Full Text Available Salbutamol sulphate (SS was precipitated by supercritical carbon dioxide (SC-CO2 using a homemade system at two different pressures. This process is characterized by spraying a methanolic solution of the drug into the supercritical fluid (SCF, extraction of the solvent by SC-CO2 and formation of drug particles. The morphology and size distribution of precipitated SS particles were characterized using scanning electron microscope and laser diffraction particle size analyzer respectively. FTIR spectra were used before and after processing to asses crystal modifications. Depending on the processing conditions, needle-like and flake-like particles with different size distributions were observed. The average size of the flake like particles was less than needle-like particles and the span parameter showed a narrower size distribution of the processed in comparison with the unprocessed materials. Analysis by FTIR showed that there was no significant effect on the structure of the drug under these processing conditions.

  11. Pharmacological Inhibition of Protein Kinase G1 Enhances Bone Formation by Human Skeletal Stem Cells Through Activation of RhoA-Akt Signaling

    Kermani, Abbas Jafari; Siersbaek, Majken S; Chen, Li;

    2015-01-01

    for several malignant and nonmalignant conditions. We screened a library of kinase inhibitors to identify small molecules that enhance bone formation by human skeletal (stromal or mesenchymal) stem cells (hMSC). We identified H-8 (known to inhibit protein kinases A, C, and G) as a potent enhancer of...... differentiation and suggest that pharmacological inhibition of PRKG1 in hMSC implanted at the site of bone defect can enhance bone regeneration. Stem Cells 2015....

  12. Pt3Co concave nanocubes: synthesis, formation understanding, and enhanced catalytic activity toward hydrogenation of styrene.

    Wang, Chenyu; Lin, Cuikun; Zhang, Lihua; Quan, Zewei; Sun, Kai; Zhao, Bo; Wang, Feng; Porter, Nathan; Wang, Yuxuan; Fang, Jiye

    2014-02-01

    We report a facile synthesis route to prepare high-quality Pt3Co nanocubes with a concave structure, and further demonstrate that these concave Pt3Co nanocubes are terminated with high-index crystal facets. The success of this preparation is highly dependent on an appropriate nucleation process with a successively anisotropic overgrowth and a preservation of the resultant high-index planes by control binding of oleyl-amine/oleic acid with a fine-tuned composition. Using a hydrogenation of styrene as a model reaction, these Pt3Co concave nanocubes as a new class of nanocatalysts with more open structure and active atomic sites located on their high-index crystallographic planes exhibit an enhanced catalytic activity in comparison with low-indexed surface terminated Pt3Co nanocubes in similar size. PMID:24382713

  13. Biofilm formation and phenotypic variation enhance predation-driven persistence of Vibrio cholerae

    Matz, Carsten; McDougald, D.; Moreno, A.M.;

    2005-01-01

    Persistence of the opportunistic bacterial pathogen Vibrio cholerae in aquatic environments is the principal cause for seasonal occurrence of cholera epidemics. This causality has been explained by postulating that V. cholerae forms biofilms in association with animate and inanimate surfaces....... Alternatively, it has been proposed that bacterial pathogens are an integral part of the natural microbial food web and thus their survival is constrained by protozoan predation. Here, we report that both explanations are interrelated. our data show that biofilms are the protective agent enabling V. cholerae to...... survive protozoan grazing while their planktonic counterparts are eliminated. Grazing on planktonic V. cholerae was found to select for the biofilm-enhancing rugose phase variant, which is adapted to the surf ace-associated niche by the production of exopolymers. Interestingly, grazing resistance in V...

  14. Ganglioside-magnetosome complex formation enhances uptake of gangliosides by cells

    Guan F

    2015-11-01

    Full Text Available Feng Guan,1 Xiang Li,1 Jia Guo,1 Ganglong Yang,1 Xiang Li2 1The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, 2Wuxi Medical School, Jiangnan University, Wuxi, People’s Republic of China Abstract: Bacterial magnetosomes, because of their nano-scale size, have a large surface-to-volume ratio and are able to carry large quantities of bioactive substances such as enzymes, antibodies, and genes. Gangliosides, a family of sialic acid-containing glycosphingolipids, function as distinctive cell surface markers and as specific determinants in cellular recognition and cell-to-cell communication. Exogenously added gangliosides are often used to study biological functions, transport mechanisms, and metabolism of their endogenous counterparts. Absorption of gangliosides into cells is typically limited by their tendency to aggregate into micelles in aqueous media. We describe here a simple strategy to remove proteins from the magnetosome membrane by sodium dodecyl sulfate treatment, and efficiently immobilize a ganglioside (GM1 or GM3 on the magnetosome by mild ultrasonic treatment. The maximum of 11.7±1.2 µg GM1 and 11.6±1.5 µg GM3 was loaded onto 1 mg magnetosome, respectively. Complexes of ganglioside-magnetosomes stored at 4°C for certain days presented the consistent stability. The use of GM1-magnetosome complex resulted in the greatest enhancement of ganglioside incorporation by cells. GM3-magnetosome complex significantly inhibited EGF-induced phosphorylation of the epidermal growth factor receptor. Both of these effects were further enhanced by the presence of a magnetic field. Keywords: bacterial magnetosome, nanoparticle, cellular uptake, ganglioside, inhibition

  15. Technical Note: Enhanced reactivity of nitrogenous organohalogen formation from plant litter to bacteria

    J. J. Wang

    2012-06-01

    Full Text Available C1/C2 organohalogens (organohalogens with one or two carbon atoms can have significant environmental toxicity and ecological impact, such as carcinogenesis, ozone depletion and global warming. Natural halogenation processes have been identified for a wide range of natural organic matter, including soils, plant and animal debris, algae, and fungi. Yet, few have considered these organohalogens generated from the ubiquitous bacteria, one of the largest biomass pools on Earth. Here, we report and confirm the formation of chloroform (CHCl3 dichloro-acetonitrile (CHCl2CN, chloral hydrate (CCl3CH(OH2 and their brominated analogues by direct halogenation of seven strains of common bacteria and nine cellular monomers. Comparing different major C stocks during litter decomposition stages in terrestrial ecosystems, from plant litter, decomposed litter, to bacteria, increasing reactivity for nitrogenous organohalogen yield was observed with decreasing C/N ratio. Our results raise the possibility that natural halogenation of bacteria represents a significant and overlooked contribution to global organohalogen burdens. As bacteria are decomposers that alter the C quality by transforming organic matter pools from high to low C/N ratio and constitute a large organic N pool, the bacterial activity is expected to affect the C, N, and halogen cycling through natural halogenation reactions.

  16. Bioaugmentation and enhanced formation of microbial granules used in aerobic wastewater treatment.

    Ivanov, Volodymyr; Wang, Xiao-Hui; Tay, Stephen Tiong-Lee; Tay, Joo-Hwa

    2006-04-01

    Microbial aggregates of an aerobic granular sludge can be used for the treatment of industrial or municipal wastewater, but their formation from a microbial activated sludge requires several weeks. Therefore, the aim of this research was the selection of microbial cultures to shorten the granule-forming period from several weeks to a few days. An enrichment culture with the ability to accelerate granulation was obtained by repeating the selection and batch cultivation of fast-settling microbial aggregates isolated from the aerobic granular sludge. Bacterial cultures of Klebsiella pneumoniae strain B and Pseudomonas veronii strain F, with self-aggregation indexes of 65 and 51%, respectively, and a coaggregation index of 58%, were isolated from the enrichment culture. A mixture of these strains with the activated sludge was used as an inoculum in an experimental sequencing batch reactor to start up an aerobic granulation process. Aerobic granules with a mean diameter of 446+/-76 microm were formed in an experiment after 8 days of cultivation, but microbial granules were absent in controls. Considering biosafety issues, K. pneumoniae strain B was excluded from further studies, but P. veronii strain F was selected for larger-scale testing. PMID:16091930

  17. Bioaugmentation and enhanced formation of microbial granules used in aerobic wastewater treatment

    Ivanov, V.; Wang, Xiao-Hui; Tay, S.T.L.; Tay, Joo-Hwa [Nanyang Technological Univ., Singapore (Singapore). School of Civil and Environmental Engineering

    2006-04-15

    Microbial aggregates of an aerobic granular sludge can be used for the treatment of industrial or municipal wastewater, but their formation from a microbial activated sludge requires several weeks. Therefore, the aim of this research was the selection of microbial cultures to shorten the granule-forming period from several weeks to a few days. An enrichment culture with the ability to accelerate granulation was obtained by repeating the selection and batch cultivation of fast-settling microbial aggregates isolated from the aerobic granular sludge. Bacterial cultures of Klebsiella pneumoniae strain B and Pseudomonas veronii strain F, with self-aggregation indexes of 65 and 51%, respectively, and a coaggregation index of 58%, were isolated from the enrichment culture. A mixture of these strains with the activated sludge was used as an inocolum in an experimental sequencing batch reactor to start up an aerobic granulation process. Aerobic granules with a mean diameter of 446{+-}76 {mu}m were formed in an experiment after 8 days of cultivation, but microbial granules were absent in controls. Considering biosafety issues, K. pneumoniae strain B was excluded from further studies, but P. veronii strain F was selected for larger-scale testing. (orig.)

  18. Enhanced conformational sampling to visualize a free-energy landscape of protein complex formation

    Iida, Shinji; Nakamura, Haruki; Higo, Junichi

    2016-01-01

    We introduce various, recently developed, generalized ensemble methods, which are useful to sample various molecular configurations emerging in the process of protein–protein or protein–ligand binding. The methods introduced here are those that have been or will be applied to biomolecular binding, where the biomolecules are treated as flexible molecules expressed by an all-atom model in an explicit solvent. Sampling produces an ensemble of conformations (snapshots) that are thermodynamically probable at room temperature. Then, projection of those conformations to an abstract low-dimensional space generates a free-energy landscape. As an example, we show a landscape of homo-dimer formation of an endothelin-1-like molecule computed using a generalized ensemble method. The lowest free-energy cluster at room temperature coincided precisely with the experimentally determined complex structure. Two minor clusters were also found in the landscape, which were largely different from the native complex form. Although those clusters were isolated at room temperature, with rising temperature a pathway emerged linking the lowest and second-lowest free-energy clusters, and a further temperature increment connected all the clusters. This exemplifies that the generalized ensemble method is a powerful tool for computing the free-energy landscape, by which one can discuss the thermodynamic stability of clusters and the temperature dependence of the cluster networks. PMID:27288028

  19. DHX36 enhances RIG-I signaling by facilitating PKR-mediated antiviral stress granule formation.

    Ji-Seung Yoo

    2014-03-01

    Full Text Available RIG-I is a DExD/H-box RNA helicase and functions as a critical cytoplasmic sensor for RNA viruses to initiate antiviral interferon (IFN responses. Here we demonstrate that another DExD/H-box RNA helicase DHX36 is a key molecule for RIG-I signaling by regulating double-stranded RNA (dsRNA-dependent protein kinase (PKR activation, which has been shown to be essential for the formation of antiviral stress granule (avSG. We found that DHX36 and PKR form a complex in a dsRNA-dependent manner. By forming this complex, DHX36 facilitates dsRNA binding and phosphorylation of PKR through its ATPase/helicase activity. Using DHX36 KO-inducible MEF cells, we demonstrated that DHX36 deficient cells showed defect in IFN production and higher susceptibility in RNA virus infection, indicating the physiological importance of this complex in host defense. In summary, we identify a novel function of DHX36 as a critical regulator of PKR-dependent avSG to facilitate viral RNA recognition by RIG-I-like receptor (RLR.

  20. Influence of ultrasound enhancement on chlorine dioxide consumption and disinfection by-products formation for secondary effluents disinfection.

    Zhou, Xiaoqin; Zhao, Junyuan; Li, Zifu; Lan, Juanru; Li, Yajie; Yang, Xin; Wang, Dongling

    2016-01-01

    Chlorine dioxide (ClO2) has been promoted as an alternative disinfectant because of its high disinfection efficiency and less formation of organic disinfection by-products (DBPs). However, particle-associated microorganisms could be protected during the disinfection process, which decreases the disinfection efficiency or increases the required dosage. Besides, the formation of inorganic disinfection by-products is a significant concern in environment health. Ultrasound (US)-combined disinfection methods are becoming increasingly attractive because they are efficient and environmentally friendly. In this study, US was introduced as an enhancement method to identify its influence on ClO2 demand reduction and to minimize the production of potential DBPs for secondary effluents disinfection. Fecal coliform was used as an indicator, and DBPs, including trichloromethane (TCM), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), chlorite (ClO2(-)), and chlorate (ClO3(-)), were analyzed to observe the potential DBPs formation. Results show that US pretreatment could reduce half of ClO2 dosage compared with ClO2 disinfection alone for the same disinfection efficiency, and that an input power density of 2.64 kJ/L pretreatment with the 1.5mg/L ClO2 was enough to meet the discharge requirement in China (i.e., fecal coliform below 1000 CFU/L for Class 1A) for secondary effluent disinfection, and the ClO2(-) concentration in the disinfection effluent was only 1.37 mg/L at the same time. Furthermore, the different effects of US on the two processes (US as pretreatment and simultaneous US/ClO2 disinfection) were also analyzed, including deagglomerating, cell damage, and synergistic disinfection as well as degasing/sonolysis. It was proved that the production of TCM, DCAA, and TCAA was insignificantly influenced with the introduction of US, but US pretreatment did reduce the production of ClO2(-) and ClO3(-) effectually. In general, US pretreatment could be a better option for

  1. Stents Eluting 6-Mercaptopurine Reduce Neointima Formation and Inflammation while Enhancing Strut Coverage in Rabbits.

    Matthijs S Ruiter

    Full Text Available The introduction of drug-eluting stents (DES has dramatically reduced restenosis rates compared with bare metal stents, but in-stent thrombosis remains a safety concern, necessitating prolonged dual anti-platelet therapy. The drug 6-Mercaptopurine (6-MP has been shown to have beneficial effects in a cell-specific fashion on smooth muscle cells (SMC, endothelial cells and macrophages. We generated and analyzed a novel bioresorbable polymer coated DES, releasing 6-MP into the vessel wall, to reduce restenosis by inhibiting SMC proliferation and decreasing inflammation, without negatively affecting endothelialization of the stent surface.Stents spray-coated with a bioresorbable polymer containing 0, 30 or 300 μg 6-MP were implanted in the iliac arteries of 17 male New Zealand White rabbits. Animals were euthanized for stent harvest 1 week after implantation for evaluation of cellular stent coverage and after 4 weeks for morphometric analyses of the lesions.Four weeks after implantation, the high dose of 6-MP attenuated restenosis with 16% compared to controls. Reduced neointima formation could at least partly be explained by an almost 2-fold induction of the cell cycle inhibiting kinase p27Kip1. Additionally, inflammation score, the quantification of RAM11-positive cells in the vessel wall, was significantly reduced in the high dose group with 23% compared to the control group. Evaluation with scanning electron microscopy showed 6-MP did not inhibit strut coverage 1 week after implantation.We demonstrate that novel stents coated with a bioresorbable polymer coating eluting 6-MP inhibit restenosis and attenuate inflammation, while stimulating endothelial coverage. The 6-MP-eluting stents demonstrate that inhibition of restenosis without leaving uncovered metal is feasible, bringing stents without risk of late thrombosis one step closer to the patient.

  2. Enhanced inhibition of bacterial biofilm formation and reduced leukocyte toxicity by chloramphenicol:β-cyclodextrin:N-acetylcysteine complex.

    Aiassa, Virginia; Zoppi, Ariana; Becerra, M Cecilia; Albesa, Inés; Longhi, Marcela R

    2016-11-01

    The purpose of this study was to improve the physicochemical and biological properties of chloramphenicol (CP) by multicomponent complexation with β-cyclodextrin (β-CD) and N-acetylcysteine (NAC). The present work describes the ability of solid multicomponent complex (MC) to decrease biomass and cellular activity of Staphylococcus by crystal violet and XTT assay, and leukocyte toxicity, measuring the increase of reactive oxygen species by chemiluminescence, and using 123-dihydrorhodamine. In addition, MC was prepared by the freeze-drying or physical mixture methods, and then characterized by scanning electron microscopy and powder X-ray diffraction. Nuclear magnetic resonance and phase solubility studies provided information at the molecular level on the structure of the MC and its association binding constants, respectively. The results obtained allowed us to conclude that MC formation is an effective pharmaceutical strategy that can reduce CP toxicity against leukocytes, while enhancing its solubility and antibiofilm activity. PMID:27516318

  3. Formation of Native and Non-native Interactions in Ensembles of Denatured ACBP Molecules from Paramagnetic Relaxation Enhancement Studies

    Kristjansdottir, S.; Lindorff-Larsen, Kresten; Fieber, W.; Dobson, Christopher M.; Vendruscolo, Michele; Poulsen, Flemming M.

    2005-01-01

    the residual structure in the denatured state of ACBP under these different conditions has enabled us to infer that regions in the N and C-terminal parts of the protein sequence have a high tendency to interact in the unfolded state under physiological conditions. By comparing the structural features...... in the denatured states with those in the transition state for folding we also provided new insights into the mechanism of formation of the native state of this protein. Keywords: protein folding; denatured state; NMR; molecular dynamics; structural studies Abbreviations: ACBP, acyl coenzyme A......Paramagnetic relaxation enhancement measurements in the denatured state of ACBP have provided distance restraints that have been used in computer simulations to determine the conformational ensembles representing the denatured states of ACBP under a variety of conditions. A detailed comparison of...

  4. Dissolution rate enhancement of clarithromycin using ternary ground mixtures: nanocrystal formation.

    Shahbaziniaz, Malihe; Foroutan, Seyed Mohsen; Bolourchian, Noushin

    2013-01-01

    Clarithromycin (CLA), a broad-spectrum macrolide, is a poorly soluble drug with dissolution rate limited absorption. The aim of this investigation was to prepare CLA nanoparticles from a ternary ground mixture in the presence of sodium lauryl sulfate (SLS) and polyvinyl pyrrolidone (PVP) as co-grinding water-soluble compounds, in order to improve the drug dissolution rate. Different weight ratios of CLA: SLS: PVP were ground in a dry process by planetary ball mill using different grinding ball size. Following the dissolution rate study, physical properties of the best dissolved co-ground formulation was studied. The accelerated stability studies were also conducted on the co-ground formulation. The results revealed that the dissolution rate of ternary ground mixtures was much higher than that of the intact drug (p < 0.001). Decreasing the grinding ball size and weight with the same rotation speed resulted in particles with decreased dissolution. On the other hand, increasing the PVP concentration in the formulations reduced the drug dissolution. Dissolution efficiencies (DE10 and DE30) for the best dissolved formulation, which consisted of the equal ratio of each co-ground component, were 8.7 and 5 folds higher than the untreated CLA, respectively. This formulation formed nanocrystals with enhanced solubility after dispersing in water. X-ray diffraction, differential scanning calorimetry and infrared spectrophotometry confirmed no chemical interaction and phase transition during the process. Accelerated stability studies confirmed that the co-ground mixture almost remained unchanged in terms of dissolution rate, drug assay and particle size after exposing in stability conditions for three months. PMID:24523739

  5. Enhancement of human ACAT1 gene expression to promote the macrophage-derived foam cell formation by dexamethasone

    Li YANG; Ta Yuan CHANG; Bo Liang LI; Jin Bo YANG; Jia CHEN; Guang Yao YU; Pei ZHOU; Lei LEI; Zhen Zhen WANG; Catherine CY CHANG; XinYing YANG

    2004-01-01

    In macrophages, the accumulation of cholesteryl esters synthesized by the activated acyl-coenzyme A:cholesterol acyltransferase-1 (ACAT1) results in the foam cell formation, a hallmark of early atherosclerotic lesions. In this study,with the treatment of a glucocorticoid hormone dexamethasone (Dex), lipid staining results clearly showed the large accumulation of lipid droplets containing cholesteryl esters in THP- 1-derived macrophages exposed to lower concentration of the oxidized low-density lipoprotein (ox-LDL). More notably, when treated together with specific anti-ACAT inhibitors, the abundant cholesteryl ester accumulation was markedly diminished in THP-l-derived macrophages, confirming that ACAT is the key enzyme responsible for intracellular cholesteryl ester synthesis. RT-PCR and Western blot results indicated that Dex caused up-regulation of human ACAT1 expression at both the mRNA and protein levels in THP-1 and THP- 1-derived macrophages. The luciferase activity assay demonstrated that Dex could enhance the activity of human ACAT1 gene P1 promoter, a major factor leading to the ACAT1 activation, in a cell-specific manner.Further experimental evidences showed that a glucocorticoid response element (GRE) located within human ACAT1gene P1 promoter to response to the elevation of human ACAT1 gene expression by Dex could be functionally bound with glucocorticoid receptor (GR) proteins. These data supported the hypothesis that the clinical treatment with Dex,which increased the incidence of atherosclerosis, may in part due to enhancing the ACAT1 expression to promote the accumulation of cholesteryl esters during the macrophage-derived foam cell formation, an early stage of atherosclerosis.

  6. Hydraulic fracturing to enhance geothermal energy recovery in deep and tight formations. Modell approach in petrothermy research project OPTIRISS

    Rafiee, M.M.; Schmitz, S.; Barsch, M. [DBI - Gastechnologisches Institut gGmbH, Freiberg (Germany)

    2013-08-01

    In Germany numerous projects were successfully conducted in developments of geothermal energy which applied so far mostly for the hydrothermal deposit type. In Thuringia and Saxony there are currently project developments of geothermal resource taking into account for deep, tight formations in petrothermy and Enhanced geothermal system, (EGS). One of the potential tasks in generating these petrothermal producers and in the design of the underground power plant appears to be hydraulic fracturing with multi frac method. This is to create the heat exchanger surfaces in the rock and ensure maximum volumetric flow through it. Therefore it is very important for a sustainable heat production. However the promise of its adequate conductivity in the deep formation is one of the dominant contests in geothermal energy industry. In a multi frac method, two wells (normally horizontal wellbores at different depths) are drilled in direction of minimum horizontal stress of the formation rock. By multiple frac operation in separate sections, flow paths are generated between the wells through which it is possible to extract the heat from the rock. The numerical simulation of hydraulic fracture propagation processes in the rock is mainly from the research in the area of oil and gas industry. These techniques are mainly used for very low permeable formations in petroleum engineering (e.g. Shale gas). The development is at the beginning for EGS (e.g. granites). In this work single and multi fracking propagation processes in a synthetic example of deep hard formation are investigated. The numerical simulation is carried out to design and characterize frac processes and frac dimensions. Sensitivities to various rock parameters and different process designs are examined and optimum criteria are concluded. This shows that the minimum stress profile has the most effective role and should be modelled properly. The analysis indicates the optimum fracture length and height for adequate thermal

  7. Sonic hedgehog enhances somite cell viability and formation of primary slow muscle fibers in avian segmented mesoderm.

    Cann, G M; Lee, J W; Stockdale, F E

    1999-09-01

    Primary skeletal muscle fibers first form in the segmented portions of paraxial mesoderm called somites. Although the neural tube and notochord are recognized as crucial in patterning myogenic cell lineages during avian and mammalian somitic myogenesis, the source, identities, and actions of the signals governing this process remain controversial. It has been shown that signals emanating from the ventral neural tube and/or notochord alone or Shh alone serve to activate MyoD expression in somites. However, beyond a role in initiating MyoD expression, little is known about the effects of Shh on primary muscle fiber formation in somites of higher vertebrates. The studies reported here investigate how the ventral neural tube promotes myogenesis and compare the effects of the ventral neural tube with those of purified Shh protein on fiber formation in somites. We show that purified Shh protein mimics actions of the ventral neural tube on somites including initiation of muscle fiber formation, enhancement of numbers of primary muscle fibers, and particularly, the formation of primary fibers that express slow myosin. There is a marked increase in slow myosin expression in fibers in response to Shh as somites mature. The effects of ventral neural tube on fiber formation can be blocked by disrupting the Shh signaling pathway by increasing the activity of somitic cyclic AMP-dependent protein kinase A. Furthermore, it was demonstrated that apoptosis is a dominant fate of somite cells, but not somitic muscle fibers, when cultured in the absence of the neural tube, and that application of Shh protein to somites reduced apoptosis. The block to apoptosis by Shh is a manifestation of the maturity of the somite with a progressive increase in the block as somites are displaced rostrally from somite III forward. We conclude that purified Shh protein in mimicking the effects of the ventral neural tube on segmented mesoderm can exert pleiotropic effects during primary myogenesis

  8. c-Myc Enhances Sonic Hedgehog-Induced Medulloblastoma Formation from Nestin-Expressing Neural Progenitors in Mice

    Ganesh Rao

    2003-05-01

    Full Text Available Medulloblastomas are malignant brain tumors that arise in the cerebella of children. The presumed cellsof-origin are undifferentiated precursors of granule neurons that occupy the external granule layer (EGL of the developing cerebellum. The overexpression of proteins that normally stimulate proliferation of neural progenitor cells may initiate medulloblastoma formation. Two known mitogens for neural progenitors are the c-Myc oncoprotein and Sonic hedgehog (Shh, a crucial determinant of embryonic pattern formation in the central nervous system. We modeled the ability of c-Myc and Shh to induce medulloblastoma in mice using the RCAS/tv-a system, which allows postnatal gene transfer and expression in a cell type-specific manner. We targeted the expression of Shh and c-Myc to nestin-expressing neural progenitor cells by injecting replication-competent ALV splice acceptor (RCAS vectors into the cerebella of newborn mice. Following injection with RCAS-Shh alone, 3/32 (9% mice developed medulloblastomas and 5/32 showed multifocal hyperproliferation of the EGL, possibly a precursor stage of medulloblastoma. Following injection with RCAS-Shh plus RCAS-Myc, 9/39 (23% mice developed medulloblastomas. We conclude that nestin-expressing neural progenitors, present in the cerebellum at birth, can act as the cells-of-origin for medulloblastoma, and that c-Myc cooperates with Shh to enhance tumorigenicity.

  9. Enhanced activity of ADP glucose pyrophosphorylase and formation of starch induced by Azospirillum brasilense in Chlorella vulgaris.

    Choix, Francisco J; Bashan, Yoav; Mendoza, Alberto; de-Bashan, Luz E

    2014-05-10

    ADP-glucose pyrophosphorylase (AGPase) regulates starch biosynthesis in higher plants and microalgae. This study measured the effect of the bacterium Azospirillum brasilense on AGPase activity in the freshwater microalga Chlorella vulgaris and formation of starch. This was done by immobilizing both microorganisms in alginate beads, either replete with or deprived of nitrogen or phosphorus and all under heterotrophic conditions, using d-glucose or Na-acetate as the carbon source. AGPase activity during the first 72h of incubation was higher in C. vulgaris when immobilized with A. brasilense. This happened simultaneously with higher starch accumulation and higher carbon uptake by the microalgae. Either carbon source had similar effects on enzyme activity and starch accumulation. Starvation either by N or P had the same pattern on AGPase activity and starch accumulation. Under replete conditions, the population of C. vulgaris immobilized alone was higher than when immobilized together, but under starvation conditions A. brasilense induced a larger population of C. vulgaris. In summary, adding A. brasilense enhanced AGPase activity, starch formation, and mitigation of stress in C. vulgaris. PMID:24576433

  10. Enhanced photoelectrochemical performance of WO3/Ti photoanode due to in situ formation of a thin interfacial composite layer

    Lee, Won Jae; Shinde, Pravin S.; Go, Geun Ho; Doh, Chil Hoon

    2013-04-01

    Nanostructured WO3 thin films were prepared on titanium sheet substrates using a doctor blade technique. X-ray diffraction, Raman and field emission scanning electron microscopy studies revealed that the synthesized WO3 films are having monoclinic crystal structure, porous, polycrystalline with average grain size of ∼50 nm. The photoelectrochemical responses of WO3 films prepared on treated Ti sheets were recorded in 0.5 M H2SO4 electrolyte under simulated 100 mW/cm2 illumination. WO3 film prepared on polished Ti sheet showed considerable enhancement in photocurrent as compared to WO3 films made on unpolished and pre-oxidized Ti sheets. These results suggest that in situ formation of a thin WOx-TiOy interfacial composite layer and improved adhesion of WO3 nanoparticles owing to increased reactive sites on polished Ti substrate play a significant role in enhancing the photoresponse. Such photoanodes are potential candidates in photoelectrochemical water splitting system for hydrogen generation.

  11. Study on Sensory Quality, Antioxidant Properties, and Maillard Reaction Products Formation in Rye-Buckwheat Cakes Enhanced with Selected Spices

    Małgorzata Przygodzka

    2015-01-01

    Full Text Available The effect of selected spices included in the recipe of rye-buckwheat cakes on sensory quality, nutritional value, and Maillard reaction (MR products formation was addressed in this study. The cakes with cloves, nutmeg, allspice, cinnamon, vanilla, and spice mix addition revealed the highest overall quality values. Cakes enriched with cloves, allspice, and spice mix showed the highest rutin content and almost threefold higher available lysine contents whereas cakes enhanced with mix, cloves, and cinnamon were the richest source of phenolic compounds. The highest antioxidant capacity showed cakes with cloves and spice mix. The furosine, a marker of early stage of MR, was decreased in cakes with cloves, allspice, spice mix, and vanilla whereas fluorescent intermediatory compounds were reduced in cakes enhanced with cloves, allspice, and cinnamon. In contrast, browning index was increased as compared to cakes without spices. The FAST index was significantly lowered in all cakes enriched with spices, especially with cloves, allspice, and mix addition. The presence of cloves, allspice, and vanilla in cake formula was the most efficient in acrylamide strategy. It can be suggested that cloves, allspice, and vanilla might be used for production of safety and good quality cakes.

  12. Remarkable fluorescence enhancement versus complex formation of cationic porphyrins on the surface of ZnO nanoparticles

    Aly, Shawkat Mohammede

    2014-06-12

    Fluorescence enhancement of organic fluorophores shows tremendous potential to improve image contrast in fluorescence-based bioimaging. Here, we present an experimental study of the interaction of two cationic porphyrins, meso-tetrakis(1-methylpyridinium-4-yl)porphyrin chloride (TMPyP) and meso-tetrakis(4-N,N,N-trimethylanilinium)porphyrin chloride (TMAP), with cationic surfactant-stabilized zinc oxide nanoparticles (ZnO NPs) based on several steady-state and time-resolved techniques. We show the first experimental measurements demonstrating a clear transition from pronounced fluorescence enhancement to charge transfer (CT) complex formation by simply changing the nature and location of the positive charge of the meso substituent of the cationic porphyrins. For TMPyP, we observe a sixfold increase in the fluorescence intensity of TMPyP upon addition of ZnO NPs. Our experimental results indicate that the electrostatic binding of TMPyP with the surface of ZnO NPs increases the symmetry of the porphyrin macrocycle. This electronic communication hinders the rotational relaxation of the meso unit and/or decreases the intramolecular CT character between the cavity and the meso substituent of the porphyrin, resulting in the enhancement of the intensity of the fluorescence. For TMAP, on the other hand, the different type and nature of the positive charge resulting in the development of the CT band arise from the interaction with the surface of ZnO NPs. This observation is confirmed by the femtosecond transient absorption spectroscopy, which provides clear spectroscopic signatures of photoinduced electron transfer from TMAP to ZnO NPs. © 2014 American Chemical Society.

  13. Does glucose enhance the formation of nitrogen containing polycyclic aromatic compounds and polycyclic aromatic hydrocarbons in the pyrolysis of proline?

    Phillip F. Britt; A.C. Buchanan; Clyde V. Owens, Jr.; J. Todd Skeen [Oak Ridge National Laboratory, Oak Ridge, TN (United States). Chemical and Analytical Sciences Division

    2004-08-01

    The gas-phase pyrolysis of proline, glucose, 1-((2{prime}-carboxy)pyrrolidinyl)-1-deoxy-D-fructose (the proline Amadori compound), and a 1:1 mixture by weight of proline and glucose was investigated at high temperatures (600-840{sup o}C) and short residence time (i.e. 1.0 s) in an inert atmosphere to determine if glucose or Maillard reaction products enhance the formation of nitrogen containing polycyclic aromatic compounds (N-PACs) and polycyclic aromatic hydrocarbons (PAHs) in the pyrolysis of proline. To study the gas-phase formation of N-PACs and PAHs, the substrates were sublimed into the pyrolysis furnace at 460{sup o}C. Thermogravimetric analysis showed that glucose, the proline/glucose mixture, and the proline Amadori compound undergo solid-state decomposition reactions before subliming. Thus, the substrates were pyrolyzed in two stages: at 460{sup o}C during the sublimation and at 600-840{sup o}C. At 800{sup o}C with a residence time of 1.0 s, proline produced low yields of N-PACs, such as quinoline, isoquinoline, indole, acridine, and carbazole, and PAHs, such as phenanthrene, pyrene, benz(a)anthracene, benzofluoranthene isomers, and benzo(a)pyrene. Increasing the temperature and residence time increased the yield of these products. Under similar pyrolysis conditions, the proline Amadori compound produced 2-8 fold more N-PACs and PAHs than proline. A 1:1 mixture of proline and glucose produced a similar slate of pyrolysis products as the proline Amadori compound, but it is unclear whether the proline Amadori compound was an intermediate in the reaction. In general, the proline Amadori compound produced a higher yield of N-PACs and PAHs than the proline/glucose mixture, but glucose clearly enhances the low temperature gas-phase formation of N-PACs and PAHs from the pyrolysis of proline. 56 refs., 10 figs., 3 tabs.

  14. α-Naphthoflavone Increases Lipid Accumulation in Mature Adipocytes and Enhances Adipocyte-Stimulated Endothelial Tube Formation

    Mei-Lin Wang

    2015-04-01

    Full Text Available The aryl hydrocarbon receptor (AhR is a ligand-activated factor that regulates biological effects associated with obesity. The AhR agonists, such as environmental contaminants 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD and β-naphthoflavone (BNF, inhibit preadipocyte differentiation and interfere with the functions of adipose tissue, whereas the antagonist may have opposite or protective effects in obesity. This study investigated the effects of α-naphthoflavone (α-NF, an AhR antagonist, on adipogenesis- and angiogenesis-associated factors in mature adipocytes and on cross-talk of mature adipocytes with endothelial cells (ECs. Besides, the roles of the AhR on lipid accumulation and on secretion of vascular endothelial growth factor were also determined by introducing siRNA of AhR. Differentiated 3T3-L1 cells were treated with α-naphthoflavone (α-NF (1–5 μM for 16 h. Lipid accumulation and the expressions of AhR-associated factors in the cells were determined. The interaction between adipocytes and ECs was investigated by cultivating ECs with conditioned medium (CM from α-NF-treated mature adipocytes, followed by the determination of endothelial tube formation. The results showed that α-NF significantly increased triglyceride (TG accumulation in mature adipocytes, which was associated with increased expression of hormone-sensitive lipase (HSL, estrogen receptor (ER, as well as decreased expression of AhR, AhR nuclear translocator (ARNT, cytochrome P4501B1 (CYP1B1, and nuclear factor erythroid-2-related factor (NRF-2 proteins. In addition, CM stimulated formation of tube-like structures in ECs, and α-NF further enhanced such stimulation in association with modulated the secretions of various angiogenic mediators by mature adipocytes. Similarly, increased TG accumulation and vascular endothelial growth factor (VEGF secretion were observed in AhR-knockout cells. In conclusion, α-NF increased TG accumulation in mature adipocytes and

  15. Enhanced formation of bromate and brominated disinfection byproducts during chlorination of bromide-containing waters under catalysis of copper corrosion products.

    Hu, Jun; Qiang, Zhimin; Dong, Huiyu; Qu, Jiuhui

    2016-07-01

    Copper corrosion products (CCPs) in water distribution pipes may catalyze the reactions among disinfectant, natural organic matter (NOM), and bromide (Br(-)). This study investigated the simultaneous formation of bromate (BrO3(-)) and brominated disinfection byproducts (Br-DBPs) during chlorination of Br(-)-containing waters in the presence of three CCPs (i.e., CuO, Cu2O, and Cu(2+)). In a synthetic water, both oxidant decay and BrO3(-) formation were enhanced by CCPs, whereas the presence of humic acid (HA) significantly inhibited BrO3(-) formation due to its competition for HOBr to form Br-DBPs. In the HOClBr(-)CuO system, the BrO3(-) yield increased obviously with increasing CuO dose and initial Br(-) concentration, while the catalytic formation of Br-DBPs was rather limited. A molar conversion (Br(-) to BrO3(-)) of 22.1% was observed under CuO catalysis, compared with little conversion in the absence of CuO. In the HOClBr(-)Cu2O/Cu(2+) systems, Cu2O or Cu(2+) mainly enhanced the formation of Br-DBPs, with enhancement ratios of 69.9% and 50.1%, respectively. The degree of enhancement on Br-DBPs formation became more apparent with increasing pH, while that on BrO3(-) formation reached maximal at pH 7.6. The catalytic formation of Br-DBPs and BrO3(-) by CCPs was also verified in three filtered real waters, although to a lesser extent because of the water matrix effect. In mechanism, the CCPs promoted the formation of BrO3(-) and Br-DBPs through catalyzing the HOBr disproportionation pathway and the reaction of HOBr toward HA, respectively. PMID:27110886

  16. A multi nutrient concept to enhance synapse formation and function: science behind a medical food for Alzheimer’s disease

    Sijben John W.C.

    2011-09-01

    Full Text Available Alzheimer’s Disease (AD is the leading cause of dementia. Epidemiological studies suggest that AD is linked with poor status of nutrients including DHA, B-vitamins and the vitamins E and C. Ongoing neurodegeneration, particularly synaptic loss, leads to the classical clinical features of AD namely, memory impairment, language deterioration, and executive and visuospatial dysfunction. The main constituents of neural and synaptic membranes are phospholipids. Supplemenation of animals with three dietary precursors of phospholipids namely, DHA, uridine monophosphate and choline, results in increased levels of brain phospholipids, synaptic proteins, neurite outgrowth, dendritic spines formation (i.e. the anatomical precursors of new synapses and an improvement in learning and memory. Other nutrients act as co-factors in the synthesis pathway of neuronal membranes. For example B-vitamins are involved in methylation processes, thereby enhancing the availability of choline as a synaptic membrane precursor. A multi-nutrient concept that includes these nutrients may improve membrane integrity, thereby influencing membrane-dependent processes such as receptor function and amyloid precursor protein (APP processing, as shown by reduced amyloid production and amyloid β plaque burden, as well as toxicity. Together, these insights provided the basis for the development of a medical food for patients with AD, Souvenaid®, containing a specific combination of nutrients (Fortasyn™ Connect and designed to enhance synapse formation in AD. The effect of Souvenaid on memory and cognitive performance was recently assessed in a proof-of-concept study, SOUVENIR I, with 212 drug-naïve mild AD patients (MMSE 20-26. This proof-of-concept study demonstrated that oral nutritional supplementation with Souvenaid® for 12 weeks improves memory in patients with mild AD. To confirm and extend these findings, we have designed and initiated three additional studies. Two of

  17. Enhancement of Epimedium Fried with Suet Oil Based on in Vivo Formation of Self-Assembled Flavonoid Compound Nanomicelles

    Xiao-Bin Jia

    2012-11-01

    Full Text Available The purpose of this work was to research the enhancement of Epimedium fried with suet oil based on the in vivo formation self-assembled flavonoid nanomicelles. Taking icariin as the representative, under the action of suet oil, self-assembled nanomicelles were prepared under simulated gastrointestinal tract conditions and were characterized by dynamic light scattering and transmission electron microscopy (TEM. The experiments with icariin self-assembled nanomicelles without suet oil were done according to the above. The influence of suet oil on the transportation of icariin across Caco-2 cell monolayers and the absorption in rat intestine of self-assembled nanomicelles were evaluated. The particle size of icariin self-assembled nanomicelles with suet oil was smaller than without suet oil. The nanomicelles seemed to be monodisperse spherical particle with smooth surfaces. The icariin entrapment efficiency of self-assembled nanomicelles with suet oil was increased from 43.1% to 89.7%. In Caco-2 cell monolayers, the absorptive permeability, secretory permeability and efflux ratio of icariin self-assembled nanomicelles with suet oil was 1.26 × 10−6 cm/s, 5.91 × 10−6 cm/s and 4.69, respectively, while that of icariin self-assembled nanomicelles without suet oil was 0.62 × 10−6 cm/s, 3.00 × 10−6 cm/s, and 4.84, respectively. In rat intestinal perfusion experiments, the permeability coefficient of icariin self-assembled nanomicelles with suet oil in duodenum was higher than the value of icariin self-assembled nanomicelles without suet oil (p < 0.05. With the action of suet oil, icariin self-assembled nanomicelles were more stable and the entrapment efficiency was higher than that without suet oil, which could increase the solubility of icariin and improve its intestinal absorption. Therefore, suet oil plays a role in its enhancement.

  18. Low-Level Mechanical Vibrations can Reduce Bone Resorption and Enhance Bone Formation in the Growing Skeleton

    Xie,L.; Jacobsen, J.; Busa, B.; Donahue, L.; Miller, L.; Rubin, C.; Judex, S.

    2006-01-01

    Short durations of extremely small magnitude, high-frequency, mechanical stimuli can promote anabolic activity in the adult skeleton. Here, it is determined if such signals can influence trabecular and cortical formative and resorptive activity in the growing skeleton, if the newly formed bone is of high quality, and if the insertion of rest periods during the loading phase would enhance the efficacy of the mechanical regimen. Eight-week-old female BALB/cByJ mice were divided into four groups, baseline control (n = 8), age-matched control (n = 10), whole-body vibration (WBV) at 45 Hz (0.3 g) for 15 min day{sup -1} (n = 10), and WBV that were interrupted every second by 10 of rest (WBV-R, n = 10). In vivo strain gaging of two additional mice indicated that the mechanical signal induced strain oscillations of approximately 10 microstrain on the periosteal surface of the proximal tibia. After 3 weeks of WBV, applied for 15 min each day, osteoclastic activity in the trabecular metaphysis and epiphysis of the tibia was 33% and 31% lower (P < 0.05) than in age-matched controls. Bone formation rates (BFR{center_dot}BS{sup -1}) on the endocortical surface of the metaphysis were 30% greater (P < 0.05) in WBV than in age-matched control mice but trabecular and middiaphyseal BFR were not significantly altered. The insertion of rest periods (WBV-R) failed to potentiate the cellular effects. Three weeks of either WBV or WBV-R did not negatively influence body mass, bone length, or chemical bone matrix properties of the tibia. These data indicate that in the growing skeleton, short daily periods of extremely small, high-frequency mechanical signals can inhibit trabecular bone resorption, site specifically attenuate the declining levels of bone formation, and maintain a high level of matrix quality. If WBV prove to be efficacious in the growing human skeleton, they may be able to provide the basis for a non-pharmacological and safe means to increase peak bone mass and, ultimately

  19. The identification of goat peroxiredoxin-5 and the evaluation and enhancement of its stability by nanoparticle formation

    Feng, Xiaozhou; Liu, Juanjuan; Fan, Shuai; Liu, Fan; Li, Yadong; Jin, Yuanyuan; Bai, Liping; Yang, Zhaoyong

    2016-04-01

    An anticancer bioactive peptide (ACBP), goat peroxiredoxin-5 (gPRDX5), was identified from goat-spleen extract after immunizing the goat with gastric cancer-cell lysate. Its amino acid sequence was determined by employing 2D nano-LC-ESI-LTQ-Orbitrap MS/MS combined with Mascot database search in the goat subset of the Uniprot database. The recombinant gPRDX5 protein was acquired by heterogeneous expression in Escherichia coli. Subsequently, the anti-cancer bioactivity of the peptide was measured by several kinds of tumor cells. The results indicated that the gPRDX5 was a good anti-cancer candidate, especially for killing B16 cells. However, the peptide was found to be unstable without modification with pharmaceutical excipients, which would be a hurdle for future medicinal application. In order to overcome this problem and find an effective way to evaluate the gPRDX5, nanoparticle formation, which has been widely used in drug delivery because of its steadiness in application, less side-effects and enhancement of drug accumulation in target issues, was used here to address the issues. In this work, the gPRDX5 was dispersed into nanoparticles before delivered to B16 cells. By the nanotechnological method, the gPRDX5 was stabilized by a fast and accurate procedure, which suggests a promising way for screening the peptide for further possible medicinal applications.

  20. Crystallite formation and the enhancement and inhibition of blistering in D+ irradiated Cu: Effects of irradiation induced stresses

    A striking feature of the blistering of Cu at 300 K following D+ (120-600 keV) or H+ (100-200 keV) irradiation at 120 K is a ring of blisters around the periphery of the beam spot. The ring is separated from the central blistered region by a wide zone free from blisters. Outside the ring, for D+ energies in the range 120-300 keV, is a band decorated by crystallites. The dose dependence of this pattern of blistering has been investigated and the onset temperatures for the various artifacts determined. The lack of blistering in the zone is attributed to an inhibition of bubble growth by high levels of compressional stress. At the periphery bubble growth and blister formation is enhanced. This is attributed to the following, acting either individually or in concert: the absence of high levels of compressive stress; tensile stresses normal to the surface; and the lateral gradients of the tensile and compressive stresses. (orig.)

  1. Enhanced expression of glucose-regulated protein 78 correlates with malondialdehyde levels during the formation of liver cirrhosis in rats

    ZHANG, YUN; ZHANG, HUIYING; ZHAO, ZHONGFU; LV, MINLI; JIA, JIANTAO; ZHANG, LILI; TIAN, XIAOXIA; CHEN, YUNXIA; LI, BAOHONG; LIU, MINGSHE; HAN, DEWU; JI, CHENG

    2015-01-01

    The aim of the present study was to explore the role of glucose-regulated protein 78 (GRP78) in the development of liver cirrhosis promoted by intestinal endotoxemia in rats. Fifty-one male Wistar rats were randomly divided into the liver cirrhosis 4-week, 6-week and 8-week groups and the normal control group at each time point. Liver cirrhosis was induced by employing multiple pathogenic factors in the rats. Blood and liver tissues were collected. The levels of alanine aminotransferase (ALT), homocysteine, endotoxin and tumor necrosis factor-α (TNF-α) in the plasma, and TNF-α, malondialdehyde (MDA) and procollagen type III peptide (PIIIP) in the liver tissues were determined. The mRNA and protein expression levels of GRP78 in the liver were detected using reverse transcription-quantitative polymerase chain reaction and immunohistochemistry. Morphological changes were observed through hematoxylin and eosin and van Gieson staining of the liver. Liver cirrhosis caused marked histopathological changes to the livers of the rats. Following significant increases in the levels of ALT, homocysteine, endotoxin and TNF-α in the plasma, and TNF-α, MDA and PIIIP in the liver tissues of all experimental groups with the progression of liver cirrhosis, the mRNA and protein expression levels of GRP78 also gradually increased. In addition, correlation analysis indicated that the enhanced expression of GRP78 correlated with the MDA levels of the rats during the formation of liver cirrhosis. PMID:26668603

  2. The First Ground Level Enhancement Event of Solar Cycle 24: Direct Observation of Shock Formation and Particle Release Heights

    Gopalswamy, N.; Xie, H.; Akiyama, S.; Yashiro, S.; Usoskin, I. G.; Davila, J. M.

    2013-01-01

    We report on the 2012 May 17 ground level enhancement (GLE) event, which is the first of its kind in solar cycle 24. This is the first GLE event to be fully observed close to the surface by the Solar Terrestrial Relations Observatory (STEREO) mission.We determine the coronal mass ejection (CME) height at the start of the associated metric type II radio burst (i.e., shock formation height) as 1.38 Rs (from the Sun center). The CME height at the time of GLE particle release was directly measured from a STEREO image as 2.32 Rs, which agrees well with the estimation from CME kinematics. These heights are consistent with those obtained for cycle-23 GLEs using back-extrapolation. By contrasting the 2012 May 17 GLE with six other non-GLE eruptions from well-connected regions with similar or larger flare sizes and CME speeds, we find that the latitudinal distance from the ecliptic is rather large for the non-GLE events due to a combination of non-radial CME motion and unfavorable solar B0 angle, making the connectivity to Earth poorer. We also find that the coronal environment may play a role in deciding the shock strength.

  3. The identification of goat peroxiredoxin-5 and the evaluation and enhancement of its stability by nanoparticle formation

    Feng, Xiaozhou; Liu, Juanjuan; Fan, Shuai; Liu, Fan; Li, Yadong; Jin, Yuanyuan; Bai, Liping; Yang, Zhaoyong

    2016-01-01

    An anticancer bioactive peptide (ACBP), goat peroxiredoxin-5 (gPRDX5), was identified from goat-spleen extract after immunizing the goat with gastric cancer-cell lysate. Its amino acid sequence was determined by employing 2D nano-LC-ESI-LTQ-Orbitrap MS/MS combined with Mascot database search in the goat subset of the Uniprot database. The recombinant gPRDX5 protein was acquired by heterogeneous expression in Escherichia coli. Subsequently, the anti-cancer bioactivity of the peptide was measured by several kinds of tumor cells. The results indicated that the gPRDX5 was a good anti-cancer candidate, especially for killing B16 cells. However, the peptide was found to be unstable without modification with pharmaceutical excipients, which would be a hurdle for future medicinal application. In order to overcome this problem and find an effective way to evaluate the gPRDX5, nanoparticle formation, which has been widely used in drug delivery because of its steadiness in application, less side-effects and enhancement of drug accumulation in target issues, was used here to address the issues. In this work, the gPRDX5 was dispersed into nanoparticles before delivered to B16 cells. By the nanotechnological method, the gPRDX5 was stabilized by a fast and accurate procedure, which suggests a promising way for screening the peptide for further possible medicinal applications. PMID:27074889

  4. The identification of goat peroxiredoxin-5 and the evaluation and enhancement of its stability by nanoparticle formation.

    Feng, Xiaozhou; Liu, Juanjuan; Fan, Shuai; Liu, Fan; Li, Yadong; Jin, Yuanyuan; Bai, Liping; Yang, Zhaoyong

    2016-01-01

    An anticancer bioactive peptide (ACBP), goat peroxiredoxin-5 (gPRDX5), was identified from goat-spleen extract after immunizing the goat with gastric cancer-cell lysate. Its amino acid sequence was determined by employing 2D nano-LC-ESI-LTQ-Orbitrap MS/MS combined with Mascot database search in the goat subset of the Uniprot database. The recombinant gPRDX5 protein was acquired by heterogeneous expression in Escherichia coli. Subsequently, the anti-cancer bioactivity of the peptide was measured by several kinds of tumor cells. The results indicated that the gPRDX5 was a good anti-cancer candidate, especially for killing B16 cells. However, the peptide was found to be unstable without modification with pharmaceutical excipients, which would be a hurdle for future medicinal application. In order to overcome this problem and find an effective way to evaluate the gPRDX5, nanoparticle formation, which has been widely used in drug delivery because of its steadiness in application, less side-effects and enhancement of drug accumulation in target issues, was used here to address the issues. In this work, the gPRDX5 was dispersed into nanoparticles before delivered to B16 cells. By the nanotechnological method, the gPRDX5 was stabilized by a fast and accurate procedure, which suggests a promising way for screening the peptide for further possible medicinal applications. PMID:27074889

  5. Surface modification of PCL-TCP scaffolds improve interfacial mechanical interlock and enhance early bone formation : An in vitro and in vivo characterization

    Yeo, A.; Wong, W. J.; Khoo, H. H.; Teoh, S. H.

    2010-01-01

    Pretreatment of polycaprolactone-20% tricalcium phosphate (PCL-TCP) scaffolds under alkaline conditions can be utilized to alter surface characteristics for enhanced early bone formation. PCL-TCP scaffolds were treated with sodium hydroxide (NaOH) at various time intervals (group A: untreated, group

  6. Hypertonic saline enhances host response to bacterial challenge by augmenting receptor-independent neutrophil intracellular superoxide formation.

    Shields, Conor J

    2012-02-03

    OBJECTIVE: This study sought to determine whether hypertonic saline (HTS) infusion modulates the host response to bacterial challenge. METHODS: Sepsis was induced in 30 Balb-C mice by intraperitoneal injection of Escherichia coli (5 x 107 organisms per animal). In 10 mice, resuscitation was performed at 0 and 24 hours with a 4 mL\\/kg bolus of HTS (7.5% NaCl), 10 animals received 4 mL\\/kg of normal saline (0.9% NaCl), and the remaining animals received 30 mL\\/kg of normal saline. Samples of blood, spleen, and lung were cultured at 8 and 36 hours. Polymorphonucleocytes were incubated in isotonic or hypertonic medium before culture with E. coli. Phagocytosis was assessed by flow cytometry, whereas intracellular bacterial killing was measured after inhibition of phagocytosis with cytochalasin B. Intracellular formation of free radicals was assessed by the molecular probe CM-H(2)DCFDA. Mitogen-activated protein (MAP) kinase p38 and ERK-1 phosphorylation, and nuclear factor kappa B (NFkappaB) activation were determined. Data are represented as means (SEM), and an analysis of variance test was performed to gauge statistical significance. RESULTS: Significantly reduced bacterial culture was observed in the animals resuscitated with HTS when compared with their NS counterparts, in blood (51.8 +\\/- 4.3 vs. 82.0 +\\/- 3.3 and 78.4 +\\/- 4.8, P = 0.005), lung (40.0 +\\/- 4.1 vs. 93.2 +\\/- 2.1 and 80.9 +\\/- 4.7, P = 0.002), and spleen (56.4 +\\/- 3.8 vs. 85.4 +\\/- 4.2 and 90.1 +\\/- 5.9, P = 0.05). Intracellular killing of bacteria increased markedly (P = 0.026) and superoxide generation was enhanced upon exposure to HTS (775.78 +\\/- 23.6 vs. 696.57 +\\/- 42.2, P = 0.017) despite inhibition of MAP kinase and NFkappaB activation. CONCLUSIONS: HTS significantly enhances intracellular killing of bacteria while attenuating receptor-mediated activation of proinflammatory cascades.

  7. Enhanced formation of secondary air pollutants and aggravation of urban smog due to crop residue burning emissions in North India

    Sarkar, Chinmoy; Kumar, Vinod; Sinha, Vinayak

    2013-04-01

    implications for the oxidizing capacity of the atmosphere increased from an average value of 14 /s (N.F.E.) to 40 /s (F.E.) just due to CO, NOx and the measured aromatics. The observed increase in ozone was 10ppbV higher after sunrise on the day after the fire plume was sampled and driven by the sudden NOx availability at a site that normally falls in a NOx limited ozone production regime. The strong pollutant enhancements in carcinogenic aromatic hydrocarbons that are also highly reactive and fuel ozone and secondary organic aerosol formation when accompanied by the high NOx and CO levels resulting from crop residue burning in N. India, clearly highlight the need to address the practice of crop residue burning which strongly alters the composition and chemistry of the atmosphere with adverse effects on both air quality and health. This study is the first from within India to combine fast in-situ PTR-MS VOC emission tracer measurements with online measurements of primary pollutants and MODIS satellite data. Further targeted studies employing a comprehensive measurement suite of both aerosol and gas species are needed to assess the full impact of crop residue burning on atmospheric chemistry and regional air quality. Acknowledgement: We thank the IISER Mohali Atmospheric Chemistry Facility for data and the Ministry of Human Resource Development (MHRD),India and IISER Mohali for funding the facility. Vinod Kumar acknowledges the DST INSPIRE Fellowship programme. Chinmoy Sarkar thanks the Max Planck-DST India Partner Group on Tropospheric OH reactivity and VOCs for funding support.

  8. Chlorination of bromide-containing waters: Enhanced bromate formation in the presence ofsynthetic metal oxides and deposits formed indrinking water distribution systems

    Liu, Chao

    2013-09-01

    Bromate formation from the reaction between chlorine and bromide in homogeneous solution is a slow process. The present study investigated metal oxides enhanced bromate formation during chlorination of bromide-containing waters. Selected metal oxides enhanced the decay of hypobromous acid (HOBr), a requisite intermediate during the oxidation of bromide to bromate, via (i) disproportionation to bromate in the presence of nickel oxide (NiO) and cupric oxide (CuO), (ii) oxidation of a metal to a higher valence state in the presence of cuprous oxide (Cu2O) and (iii) oxygen formation by NiO and CuO. Goethite (α-FeOOH) did not enhance either of these pathways. Non-charged species of metal oxides seem to be responsible for the catalytic disproportionation which shows its highest rate in the pH range near the pKa of HOBr. Due to the ability to catalyze HOBr disproportionation, bromate was formed during chlorination of bromide-containing waters in the presence of CuO and NiO, whereas no bromate was detected in the presence of Cu2O and α-FeOOH for analogous conditions. The inhibition ability of coexisting anions on bromate formation at pH 8.6 follows the sequence of phosphate>>sulfate>bicarbonate/carbonate. A black deposit in a water pipe harvested from a drinking water distribution system exerted significant residual oxidant decay and bromate formation during chlorination of bromide-containing waters. Energy dispersive spectroscopy (EDS) analyses showed that the black deposit contained copper (14%, atomic percentage) and nickel (1.8%, atomic percentage). Cupric oxide was further confirmed by X-ray diffraction (XRD). These results indicate that bromate formation may be of concern during chlorination of bromide-containing waters in distribution systems containing CuO and/or NiO. © 2013 Elsevier Ltd.

  9. How to start with technology-enhanced formative assessment of 21st century skills in your classroom(s)?

    Rusman, Ellen; Martínez-Monés, Alejandra; Tasouris, Christodoulos; Economou, Anastasia

    2014-01-01

    Workshop participants will learn to: Understand the reasons behind the shift from assessment of learning to assessment for learning; Make a difference between the objectives of formative and summative assessment; Distinguish between different formative eAassessment methods; Understand the benefits a

  10. Interspecies interactions result in enhanced biofilm formation by co-cultures of bacteria isolated from a food processing environment

    Røder, Henriette Lyng; Raghupathi, Prem Krishnan; Herschend, Jakob;

    2015-01-01

    Bacterial attachment and biofilm formation can lead to poor hygienic conditions in food processing environments. Furthermore, interactions between different bacteria may induce or promote biofilm formation. In this study, we isolated and identified a total of 687 bacterial strains from seven......-culture biofilm production with high relevance for food safety and food production facilities....

  11. Enhanced coagulation with powdered activated carbon or MIEX secondary treatment: a comparison of disinfection by-product formation and precursor removal.

    Watson, Kalinda; Farré, Maria José; Knight, Nicole

    2015-01-01

    The removal of both organic and inorganic disinfection by-product (DBP) precursors prior to disinfection is important in mitigating DBP formation, with halide removal being particularly important in salinity-impacted water sources. A matrix of waters of variable alkalinity, halide concentration and dissolved organic carbon (DOC) concentration were treated with enhanced coagulation (EC) followed by anion exchange (MIEX resin) or powdered activated carbon (PAC) and the subsequent disinfection by-product formation potentials (DBP-FPs) assessed and compared to DBP-FPs for untreated samples. Halide and DOC removal were also monitored for both treatment processes. Bromide and iodide adsorption by MIEX treatment ranged from 0 to 53% and 4-78%, respectively. As expected, EC and PAC treatments did not remove halides. DOC removal by EC/PAC was 70 ± 10%, while EC/MIEX enabled a DOC removal of 66 ± 12%. Despite the halide removals achieved by MIEX, increases in brominated disinfection by-product (Br-DBP) formation were observed relative to untreated samples, when favourable Br:DOC ratios were created by the treatment. However, the increases in formation were less than what was observed for the EC/PAC treated waters, which caused large increases in Br-DBP formation when high Br-DBP-forming water quality conditions occurred. The formation potential of fully chlorinated DBPs decreased after treatment in all cases. PMID:25462752

  12. Proteomic analysis of HIV-1 Nef cellular binding partners reveals a role for exocyst complex proteins in mediating enhancement of intercellular nanotube formation

    Mukerji Joya

    2012-06-01

    Full Text Available Abstract Background HIV-1 Nef protein contributes to pathogenesis via multiple functions that include enhancement of viral replication and infectivity, alteration of intracellular trafficking, and modulation of cellular signaling pathways. Nef stimulates formation of tunneling nanotubes and virological synapses, and is transferred to bystander cells via these intercellular contacts and secreted microvesicles. Nef associates with and activates Pak2, a kinase that regulates T-cell signaling and actin cytoskeleton dynamics, but how Nef promotes nanotube formation is unknown. Results To identify Nef binding partners involved in Pak2-association dependent Nef functions, we employed tandem mass spectrometry analysis of Nef immunocomplexes from Jurkat cells expressing wild-type Nef or Nef mutants defective for the ability to associate with Pak2 (F85L, F89H, H191F and A72P, A75P in NL4-3. We report that wild-type, but not mutant Nef, was associated with 5 components of the exocyst complex (EXOC1, EXOC2, EXOC3, EXOC4, and EXOC6, an octameric complex that tethers vesicles at the plasma membrane, regulates polarized exocytosis, and recruits membranes and proteins required for nanotube formation. Additionally, Pak2 kinase was associated exclusively with wild-type Nef. Association of EXOC1, EXOC2, EXOC3, and EXOC4 with wild-type, but not mutant Nef, was verified by co-immunoprecipitation assays in Jurkat cells. Furthermore, shRNA-mediated depletion of EXOC2 in Jurkat cells abrogated Nef-mediated enhancement of nanotube formation. Using bioinformatic tools, we visualized protein interaction networks that reveal functional linkages between Nef, the exocyst complex, and the cellular endocytic and exocytic trafficking machinery. Conclusions Exocyst complex proteins are likely a key effector of Nef-mediated enhancement of nanotube formation, and possibly microvesicle secretion. Linkages revealed between Nef and the exocyst complex suggest a new paradigm of

  13. Role of low-energy ion irradiation in the formation of an aluminum germanate layer on a germanium substrate by radical-enhanced atomic layer deposition

    Radical-enhanced atomic layer deposition uses oxygen radicals generated by a remote microwave-induced plasma as an oxidant to change the surface reactions of the alternately supplied trimethylaluminum precursor and oxygen radicals on a Ge substrate, which leads to the spontaneous formation of an aluminum germanate layer. In this paper, the effects that low-energy ions, supplied from a remote microwave plasma to the substrate along with the oxygen radicals, have on the surface reactions were studied. From a comparative study of aluminum oxide deposition under controlled ion flux irradiation on the deposition surface, it was found that the ions enhance the formation of the aluminum germanate layer. The plasma potential measured at the substrate position by the Langmuir probe method was 5.4 V. Assuming that the kinetic energy of ions arriving at the substrate surface is comparable to that gained by this plasma potential, such ions have sufficient energy to induce exchange reactions of surface-adsorbed Al atoms with the underlying Ge atoms without causing significant damage to the substrate. This ion-induced exchange reaction between Al and Ge atoms is inferred to be the background kinetics of the aluminum germanate formation by radical-enhanced atomic layer deposition

  14. Role of low-energy ion irradiation in the formation of an aluminum germanate layer on a germanium substrate by radical-enhanced atomic layer deposition

    Fukuda, Yukio, E-mail: y-fukuda@rs.suwa.tus.ac.jp; Yamada, Daichi; Yokohira, Tomoya; Yanachi, Kosei [Tokyo University of Science, Suwa, 5000-1 Toyohira, Chino, Nagano 391-0292 (Japan); Yamamoto, Chiaya; Yoo, Byeonghak; Sato, Tetsuya [University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan); Yamanaka, Junji [University of Yamanashi, 7-32 Miyamae, Kofu, Yamanashi 400-8511 (Japan); Takamatsu, Toshiyuki [SST Inc., 989-6 Shimadadai, Yachiyo, Chiba 276-0004 (Japan); Okamoto, Hiroshi [Hirosaki University, 3 Bunkyo, Hirosaki 036-8561 (Japan)

    2016-03-15

    Radical-enhanced atomic layer deposition uses oxygen radicals generated by a remote microwave-induced plasma as an oxidant to change the surface reactions of the alternately supplied trimethylaluminum precursor and oxygen radicals on a Ge substrate, which leads to the spontaneous formation of an aluminum germanate layer. In this paper, the effects that low-energy ions, supplied from a remote microwave plasma to the substrate along with the oxygen radicals, have on the surface reactions were studied. From a comparative study of aluminum oxide deposition under controlled ion flux irradiation on the deposition surface, it was found that the ions enhance the formation of the aluminum germanate layer. The plasma potential measured at the substrate position by the Langmuir probe method was 5.4 V. Assuming that the kinetic energy of ions arriving at the substrate surface is comparable to that gained by this plasma potential, such ions have sufficient energy to induce exchange reactions of surface-adsorbed Al atoms with the underlying Ge atoms without causing significant damage to the substrate. This ion-induced exchange reaction between Al and Ge atoms is inferred to be the background kinetics of the aluminum germanate formation by radical-enhanced atomic layer deposition.

  15. Analysis of the Enhanced Stability of R(+)-Alpha Lipoic Acid by the Complex Formation with Cyclodextrins

    Hiroshi Shimosegawa; Rie Nakane; Yoshiyuki Ishida; Yukiko Uekaji; Daisuke Nakata; Kathrin Pallauf; Gerald Rimbach; Seiichi Matsugo; Naoko Ikuta; Hironori Sugiyama; Keiji Terao

    2013-01-01

    R(+)-alpha lipoic acid (RALA) is one of the cofactors for mitochondrial enzymes and, therefore, plays a central role in energy metabolism. RALA is unstable when exposed to low pH or heat, and therefore, it is difficult to use enantiopure RALA as a pharma- and nutra-ceutical. In this study, we have aimed to stabilize RALA through complex formation with cyclodextrins (CDs). α-CD, β-CD and γ-CD were used for the formation of these RALA-CD complexes. We confirmed the complex formation using diffe...

  16. Teratoma Formation by Human Embryonic Stem Cells is site-dependent and enhanced by the presence of Matrigel

    Prokhorova, Tatyana A; Harkness, Linda M; Frandsen, Ulrik;

    2008-01-01

    When implanted into immunodeficient mice, human embryonic stem cells (hESC) give rise to teratoma, tumour-like formations containing tissues belonging to all three germ layers. The ability to form teratoma is a sine qua non characteristic of pluripotent stem cells. However, limited data is...... available regarding the effects of implantation site and the methods employed for implantation on the success rate of teratoma formation. In the present study, the rate of teratoma formation in immunodeficient mice was site-dependent: sub-cutaneous (25-100%), intratesticular (60%), intra-muscular (12.......5%) and under the kidney capsule (100%). Co-injecting the hESC with Matrigel increased subcutaneous teratoma formation efficiency from 25% to 100%. We did not observe site-specific differences in the teratoma composition. However, subcutaneous teratomas were quite distinct, easy to remove and caused...

  17. Enhancing Curiosity Using Interactive Simulations Combined with Real-Time Formative Assessment Facilitated by Open-Format Questions on Tablet Computers

    Kowalski, F V

    2013-01-01

    Students' curiosity often seems nearly nonexistent in a lecture setting; we discuss a variety of possible reasons for this, but it is the instructor who typically poses questions while only a few students, usually the better ones, respond. As we have developed and implemented the use of InkSurvey to collect real-time formative assessment, we have discovered that it can serve in an unanticipated role: to promote curiosity in engineering physics undergraduates. Curiosity often motivates creative, innovative people. To encourage such curiosity, we solicit questions submitted real-time via InkSurvey and pen-enabled mobile devices (Tablet PCs) in response to interactive simulations (applets) run either before or in class. This provides students with practice in asking questions, increases metacognition, and serves as a rich springboard from which to introduce content and/or address misconceptions. We describe the procedure for measuring curiosity and results from applying this method in a junior level electromagne...

  18. Deletion of the Scl +19 enhancer increases the blood stem cell compartment without affecting the formation of mature blood lineages

    Spensberger, Dominik; Kotsopoulou, Ekaterini; Ferreira, Rita; Broccardo, Cyril; Scott, Linda M.; Fourouclas, Nasios; Ottersbach, Katrin; Green, Anthony R.; Göttgens, Berthold

    2012-01-01

    The stem cell leukemia (Scl)/Tal1 gene is essential for normal blood and endothelial development, and is expressed in hematopoietic stem cells (HSCs), progenitors, erythroid, megakaryocytic, and mast cells. The Scl +19 enhancer is active in HSCs and progenitor cells, megakaryocytes, and mast cells, but not mature erythroid cells. Here we demonstrate that in vivo deletion of the Scl +19 enhancer (Scl Δ19/Δ19 ) results in viable mice with normal Scl expression in mature hematopoietic lineages. ...

  19. Enhanced bromate formation during chlorination of bromide-containing waters in the presence of CuO: Catalytic disproportionation of hypobromous acid

    Liu, Chao

    2012-10-16

    Bromate (BrO3 -) in drinking water is traditionally seen as an ozonation byproduct from the oxidation of bromide (Br-), and its formation during chlorination is usually not significant. This study shows enhanced bromate formation during chlorination of bromide-containing waters in the presence of cupric oxide (CuO). CuO was effective to catalyze hypochlorous acid (HOCl) or hypobromous acid (HOBr) decay (e.g., at least 104 times enhancement for HOBr at pH 8.6 by 0.2 g L-1 CuO). Significant halate concentrations were formed from a CuO-catalyzed hypohalite disproportionation pathway. For example, the chlorate concentration was 2.7 ± 0.2 μM (225.5 ± 16.7 μg L-1) after 90 min for HOCl (Co = 37 μM, 2.6 mg L-1 Cl2) in the presence of 0.2 g L-1 CuO at pH 7.6, and the bromate concentration was 6.6 ± 0.5 μM (844.8 ± 64 μg L -1) after 180 min for HOBr (Co = 35 μM) in the presence of 0.2 g L-1 CuO at pH 8.6. The maximum halate formation was at pHs 7.6 and 8.6 for HOCl or HOBr, respectively, which are close to their corresponding pKa values. In a HOCl-Br--CuO system, BrO3 - formation increases with increasing CuO doses and initial HOCl and Br- concentrations. A molar conversion (Br - to BrO3 -) of up to (90 ± 1)% could be achieved in the HOCl-Br--CuO system because of recycling of Br - to HOBr by HOCl, whereas the maximum BrO3 - yield in HOBr-CuO is only 26%. Bromate formation is initiated by the formation of a complex between CuO and HOBr/OBr-, which then reacts with HOBr to generate bromite. Bromite is further oxidized to BrO3 - by a second CuO-catalyzed process. These novel findings may have implications for bromate formation during chlorination of bromide-containing drinking waters in copper pipes. © 2012 American Chemical Society.

  20. Formation of Mg{sub 2}Ni with enhanced kinetics: Using MgH{sub 2} instead of Mg as a starting material

    Zhao Bin [Department of Materials Science, Fudan University, Shanghai 200433 (China); School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002 (China); Fang Fang [Department of Materials Science, Fudan University, Shanghai 200433 (China); Sun Dalin, E-mail: dlsun@fudan.edu.cn [Department of Materials Science, Fudan University, Shanghai 200433 (China); Zhang Qingan [School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002 (China); Wei Shiqiang [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Cao Fenglei; Sun Huai [Department of Chemistry, Shanghai Jiaotong University, Shanghai 200240 (China); Ouyang Liuzhang [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Zhu Min, E-mail: memzhu@scut.edu.cn [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China)

    2012-08-15

    At a temperature over the decomposition point (375 Degree-Sign C) of MgH{sub 2}, the formation of Mg{sub 2}Ni is greatly enhanced from the 2MgH{sub 2}+Ni system, as compared to the 2Mg+Ni system. In support of this finding, in-situ observation of X-ray absorption fine structure of the two systems indicates that Mg---Ni bonds form faster in the 2MgH{sub 2}+Ni system than in the 2Mg+Ni system. Furthermore, theoretical modeling also shows that Mg atoms are readily released from MgH{sub 2} using much less energy and thus are more available to react with Ni once the dehydrogenation of MgH{sub 2} occurs, as compared to normal Mg. - Graphical Abstract: The formation of Mg{sub 2}Ni is greatly enhanced by using MgH{sub 2} instead of Mg at a temperature higher than the MgH{sub 2} decomposition point. Highlights: Black-Right-Pointing-Pointer A new and efficient synthesis of Mg-based compounds at a reduced temperature. Black-Right-Pointing-Pointer Mg{sub 2}Ni formation is enhanced by using MgH{sub 2} instead of Mg as a starting material. Black-Right-Pointing-Pointer XAFS results show that Mg---Ni bonds are formed faster in 4MgH{sub 2}+Ni than in 4Mg+Ni. Black-Right-Pointing-Pointer DFT calculations show that Mg atoms are released from MgH{sub 2} more readily than from Mg. Black-Right-Pointing-Pointer Mg formed by MgH{sub 2} dehydrogenation is more available to react with Ni than normal Mg.

  1. Enhanced MC3T3-E1 preosteoblast response and bone formation on the addition of nano-needle and nano-porous features to microtopographical titanium surfaces

    Micro/nanotopographical modifications on titanium surfaces constitute a new process to increase osteoblast response to enhance bone formation. In this study, we utilized alkali heat treatment at high (SB-AH1) and low temperatures (SB-AH2) to nano-modify sandblasted titanium with microtopographical surfaces. Then, we evaluated the surface properties, biocompatibility and osteogenic capability of SB-AH1 and SB-AH2 in vitro and in vivo, and compared these with conventional sandblast-acid etching (SLA) and Ti control surfaces. SB-AH1 and SB-AH2 surfaces exhibited micro/nanotopographical modifications of nano-needle structures and nano-porous network layers, respectively, compared with the sole microtopographical surface of macro and micro pits on the SLA surface and the relatively smooth surface on the Ti control. SB-AH1 and SB-AH2 showed different roughness and elemental components, but similar wettability. MC3T3-E1 preosteoblasts anchored closely on the nanostructures of SB-AH1 and SB-AH2 surfaces, and these two surfaces more significantly enhanced cell proliferation and alkaline phosphatase (ALP) activity than others, while the SB-AH2 surface exhibited better cell proliferation and higher ALP activity than SB-AH1. All four groups of titanium domes with self-tapping screws were implanted in rabbit calvarial bone models, and these indicated that SB-AH1 and SB-AH2 surfaces achieved better peri-implant bone formation and implant stability, while the SB-AH2 surface achieved the best percentage of bone-implant contact (BIC%). Our study demonstrated that the micro/nanotopographical surface generated by sandblasting and alkali heat treatment significantly enhanced preosteoblast proliferation, ALP activity and bone formation in vitro and in vivo, and nano-porous network topography may further induce better preosteoblast proliferation, ALP activity and BIC%. (paper)

  2. Walk-off-induced modulation instability, temporal pattern formation, and frequency comb generation in cavity-enhanced second-harmonic generation

    Leo, F; Ricciardi, I; De Rosa, M; Coen, S; Wabnitz, S; Erkintalo, M

    2016-01-01

    We derive a time-domain mean-field equation to model the full temporal and spectral dynamics of light in singly resonant cavity-enhanced second-harmonic generation systems. We show that the temporal walk-off between the fundamental and the second-harmonic fields plays a decisive role under realistic conditions, giving rise to rich, previously unidentified nonlinear behaviour. Through linear stability analysis and numerical simulations, we discover a new kind of quadratic modulation instability which leads to the formation of optical frequency combs and associated time-domain dissipative structures. Our numerical simulations show excellent agreement with recent experimental observations of frequency combs in quadratic nonlinear media [Phys. Rev. A 91, 063839 (2015)]. Thus, in addition to unveiling a new, experimentally accessible regime of nonlinear dynamics, our work enables predictive modeling of frequency comb generation in cavity-enhanced second-harmonic generation systems.

  3. Plasma-enhanced atomic layer deposition of Cu–Mn films with formation of a MnSixOy barrier layer

    Conformal Cu–Mn seed layers were deposited by plasma enhanced atomic layer deposition (PEALD) at low temperature (120 °C), and the Mn content in the Cu–Mn alloys were controlled form 0 to approximately 10 atomic percent with various Mn precursor feeding times. Resistivity of the Cu–Mn alloy films decreased by annealing due to out-diffusion of Mn atoms. Out-diffused Mn atoms were segregated to the surface of the film and interface between a Cu–Mn alloy and SiO2, resulting in self-formed MnOx and MnSixOy, respectively. The adhesion between Cu and SiO2 was enhanced by the formation of MnSixOy. Continuous and conductive Cu–Mn seed layers were deposited with PEALD into 24 nm SiO2 trench, enabling a low temperature process, and the trench was perfectly filled using electrochemical plating under conventional conditions.

  4. Assessment of the combined approach of N-alkylation and salt formation to enhance aqueous solubility of tertiary amines using bupivacaine as a model drug

    Nielsen, Anders Bach; Frydenvang, Karla Andrea; Liljefors, Tommy;

    2005-01-01

    tertiary amine (up to a factor of 3200 at pH 8). A moderate reduction in solubility with increasing length of the alkyl chain was observed for the iodide salts of the N-alkylated bupivacaine derivatives. In case of the N-methyl-bupivacaine derivative variation of the counterion had a significant impact......Quaternary prodrug types of poorly water-soluble tertiary amines have been shown to exhibit significantly enhanced solubilities as compared to the parent amine. In the present study the combined effect of N-alkylation and salt formation to enhance aqueous solubility of tertiary amines have been...... investigated using bupivacaine as a model compound. X-ray structure analyses of selected salts were included to investigate the potential existence of correlations between salt solubility and crystal packing modes. Alkyl groups were methyl, ethyl, propyl, and butyl and the derivatives were isolated...

  5. Recombinant human bone morphogenetic protein-2 suspended in fibrin glue enhances bone formation during distraction osteogenesis in rabbits

    Li, Yunfeng; Li, Rui; Hu, Jing; Song, Donghui; Jiang, Xiaowen

    2016-01-01

    Introduction Bone morphogenetic protein-2 (BMP-2) has high potential for bone formation, but its in vivo effects are unpredictable due to the short life time. This study was designed to evaluate the effects of recombinant human (rh) BMP-2 suspended in fibrin on bone formation during distraction osteogenesis (DO) in rabbits. Material and methods The in vitro release kinetics of rhBMP-2 suspended in fibrin was tested using an enzyme-linked immunosorbent assay. Unilateral tibial lengthening for 10 mm was achieved in 48 rabbits. At the completion of osteodistraction, vehicle, fibrin, rhBMP-2 or rhBMP-2 suspended in fibrin (rhBMP-2 + fibrin) was injected into the center of the lengthened gap, with 12 animals in each group. Eight weeks later, the distracted callus was examined by histology, micro-CT and biomechanical testing. Radiographs of the distracted tibiae were taken at both 4 and 8 weeks after drug treatment. Results It was found that fibrin prolonged the life span of rhBMP-2 in vitro with sustained release during 17 days. The rhBMP-2 + fibrin treated animals showed the best results in bone mineral density, bone volume fraction, cortical bone thickness by micro-CT evaluation and mechanical properties by the three-point bending test when compared to the other groups (p < 0.05). In histological images, rhBMP-2 + fibrin treatment showed increased callus formation and better gap bridging compared to the other groups. Conclusions The results of this study suggest that fibrin holds promise to be a good carrier of rhBMP-2, and rhBMP-2 suspended in fibrin showed a stronger promoting effect on bone formation during DO in rabbits. PMID:27279839

  6. c-Myc Enhances Sonic Hedgehog-Induced Medulloblastoma Formation from Nestin-Expressing Neural Progenitors in Mice1

    Rao, Ganesh; Pedone, Carolyn A; Coffin, Cheryl M.; Holland, Eric C.; Fults, Daniel W.

    2003-01-01

    Medulloblastomas are malignant brain tumors that arise in the cerebella of children. The presumed cells-of-origin are undifferentiated precursors of granule neurons that occupy the external granule layer (EGL) of the developing cerebellum. The overexpression of proteins that normally stimulate proliferation of neural progenitor cells may initiate medulloblastoma formation. Two known mitogens for neural progenitors are the c-Myc oncoprotein and Sonic hedgehog (Shh), a crucial determinant of em...

  7. Analysis of the Enhanced Stability of R(+-Alpha Lipoic Acid by the Complex Formation with Cyclodextrins

    Hiroshi Shimosegawa

    2013-02-01

    Full Text Available R(+-alpha lipoic acid (RALA is one of the cofactors for mitochondrial enzymes and, therefore, plays a central role in energy metabolism. RALA is unstable when exposed to low pH or heat, and therefore, it is difficult to use enantiopure RALA as a pharma- and nutra-ceutical. In this study, we have aimed to stabilize RALA through complex formation with cyclodextrins (CDs. α-CD, β-CD and γ-CD were used for the formation of these RALA-CD complexes. We confirmed the complex formation using differential scanning calorimetry and showed by using HPLC analysis that complexed RALA is more stable than free RALA when subjected to humidity and high temperature or acidic pH conditions. Scanning electron microscopy studies showed that the particle size and shape differed depending on the cyclodextrin used for complexation. Further, the complexes of CD and RALA showed a different particle size distribution pattern compared with that of CD itself or that of the physical mixture of RALA and CD.

  8. Formation of Co3O4 microframes from MOFs with enhanced electrochemical performance for lithium storage and water oxidation.

    Feng, Yi; Yu, Xin-Yao; Paik, Ungyu

    2016-05-01

    Co3O4 microframes are synthesized through a template-engaged strategy via the etching of Co-Co Prussian blue analogue microcubes with ammonia solution and subsequent annealing treatment. Benefitting from their unique structural merits including 3D open structure and high porosity, these Co3O4 microframes exhibit enhanced electrochemical properties for both lithium-ion batteries and water oxidation. PMID:27078114

  9. Mannitol Does Not Enhance Tobramycin Killing of Pseudomonas aeruginosa in a Cystic Fibrosis Model System of Biofilm Formation.

    Katherine E Price

    Full Text Available Cystic Fibrosis (CF is a human genetic disease that results in the accumulation of thick, sticky mucus in the airways, which results in chronic, life-long bacterial biofilm infections that are difficult to clear with antibiotics. Pseudomonas aeruginosa lung infection is correlated with worsening lung disease and P. aeruginosa transitions to an antibiotic tolerant state during chronic infections. Tobramycin is an aminoglycoside currently used to combat lung infections in individuals with CF. While tobramycin is effective at eradicating P. aeruginosa in the airways of young patients, it is unable to completely clear the chronic P. aeruginosa infections in older patients. A recent report showed that co-addition of tobramycin and mannitol enhanced killing of P. aeruginosa grown in vitro as a biofilm on an abiotic surface. Here we employed a model system of bacterial biofilms formed on the surface of CF-derived airway cells to determine if mannitol would enhance the antibacterial activity of tobramycin against P. aeruginosa grown on a more clinically relevant surface. Using this model system, which allows the growth of robust biofilms with high-level antibiotic tolerance analogous to in vivo biofilms, we were unable to find evidence for enhanced antibacterial activity of tobramycin with the addition of mannitol, supporting the observation that this type of co-treatment failed to reduce the P. aeruginosa bacterial load in a clinical setting.

  10. ACTIVE GALACTIC NUCLEUS PAIRS FROM THE SLOAN DIGITAL SKY SURVEY. II. EVIDENCE FOR TIDALLY ENHANCED STAR FORMATION AND BLACK HOLE ACCRETION

    Active galactic nuclei (AGNs) are occasionally seen in pairs, suggesting that tidal encounters are responsible for the accretion of material by both central supermassive black holes (BHs). In Paper I of this series, we selected a sample of AGN pairs with projected separations rp –170 kpc and velocity offsets –1 from the Seventh Data Release of the Sloan Digital Sky Survey and quantified their frequency. In this paper, we address the BH accretion and recent star formation properties in their host galaxies. AGN pairs experience stronger BH accretion, as measured by their [O III] λ5007 luminosities (corrected for contribution from star formation) and Eddington ratios, than do control samples of single AGNs matched in redshift and host-galaxy stellar mass. Their host galaxies have stronger post-starburst activity and younger mean stellar ages, as indicated by stronger Hδ absorption and smaller 4000 Å break in their spectra. The BH accretion and recent star formation in the host galaxies both increase with decreasing projected separation in AGN pairs, for rp ∼–170 kpc. The intensity of BH accretion, the post-starburst strength, and the mean stellar ages are correlated between the two AGNs in a pair. The luminosities and Eddington ratios of AGN pairs are correlated with recent star formation in their host galaxies, with a scaling relation consistent with that observed in single AGNs. Our results suggest that galaxy tidal interactions enhance both BH accretion and host-galaxy star formation in close AGN pairs, even though the majority of low-redshift AGNs are not coincident with on-going interactions.

  11. Formate supplementation enhances folate-dependent nucleotide biosynthesis and prevents spina bifida in a mouse model of folic acid-resistant neural tube defects.

    Sudiwala, Sonia; De Castro, Sandra C P; Leung, Kit-Yi; Brosnan, John T; Brosnan, Margaret E; Mills, Kevin; Copp, Andrew J; Greene, Nicholas D E

    2016-07-01

    The curly tail mouse provides a model for neural tube defects (spina bifida and exencephaly) that are resistant to prevention by folic acid. The major ct gene, responsible for spina bifida, corresponds to a hypomorphic allele of grainyhead-like 3 (Grhl3) but the frequency of NTDs is strongly influenced by modifiers in the genetic background. Moreover, exencephaly in the curly tail strain is not prevented by reinstatement of Grhl3 expression. In the current study we found that expression of Mthfd1L, encoding a key component of mitochondrial folate one-carbon metabolism (FOCM), is significantly reduced in ct/ct embryos compared to a partially congenic wild-type strain. This expression change is not attributable to regulation by Grhl3 or the genetic background at the Mthfd1L locus. Mitochondrial FOCM provides one-carbon units as formate for FOCM reactions in the cytosol. We found that maternal supplementation with formate prevented NTDs in curly tail embryos and also resulted in increased litter size. Analysis of the folate profile of neurulation-stage embryos showed that formate supplementation resulted in an increased proportion of formyl-THF and THF but a reduction in proportion of 5-methyl THF. In contrast, THF decreased and 5-methyl THF was relatively more abundant in the liver of supplemented dams than in controls. In embryos cultured through the period of spinal neurulation, incorporation of labelled thymidine and adenine into genomic DNA was suppressed by supplemental formate, suggesting that de novo folate-dependent biosynthesis of nucleotides (thymidylate and purines) was enhanced. We hypothesise that reduced Mthfd1L expression may contribute to susceptibility to NTDs in the curly tail strain and that formate acts as a one-carbon donor to prevent NTDs. PMID:26924399

  12. Osteoblast-Specific γ-Glutamyl Carboxylase-Deficient Mice Display Enhanced Bone Formation With Aberrant Mineralization.

    Azuma, Kotaro; Shiba, Sachiko; Hasegawa, Tomoka; Ikeda, Kazuhiro; Urano, Tomohiko; Horie-Inoue, Kuniko; Ouchi, Yasuyoshi; Amizuka, Norio; Inoue, Satoshi

    2015-07-01

    Vitamin K is a fat-soluble vitamin that is necessary for blood coagulation. In addition, it has bone-protective effects. Vitamin K functions as a cofactor of γ-glutamyl carboxylase (GGCX), which activates its substrates by carboxylation. These substrates are found throughout the body and examples include hepatic blood coagulation factors. Furthermore, vitamin K functions as a ligand of the nuclear receptor known as steroid and xenobiotic receptor (SXR) and its murine ortholog, pregnane X receptor (PXR). We have previously reported on the bone-protective role of SXR/PXR signaling by demonstrating that systemic Pxr-knockout mice displayed osteopenia. Because systemic Ggcx-knockout mice die shortly after birth from severe hemorrhage, the GGCX-mediated effect of vitamin K on bone metabolism has been difficult to evaluate. In this work, we utilized Ggcx-floxed mice to generate osteoblast-specific GGCX-deficient (Ggcx(Δobl/Δobl)) mice by crossing them with Col1-Cre mice. The bone mineral density (BMD) of Ggcx(Δobl/Δobl) mice was significantly higher than that of control Col1-Cre (Ggcx(+/+)) mice. Histomorphometrical analysis of trabecular bones in the proximal tibia showed increased osteoid volume and a higher rate of bone formation in Ggcx(Δobl/Δobl) mice. Histomorphometrical analysis of cortical bones revealed a thicker cortical width and a higher rate of bone formation in Ggcx(Δobl/Δobl) mice. Electron microscopic examination revealed disassembly of mineralized nodules and aberrant calcification of collagen fibers in Ggcx(Δobl/Δobl) mice. The mechanical properties of bones from Ggcx(Δobl/Δobl) mice tended to be stronger than those from control Ggcx(+/+) mice. These results suggest that GGCX in osteoblasts functions to prevent abnormal mineralization in bone formation, although this function may not be a prerequisite for the bone-protective effect of vitamin K. PMID:25600070

  13. Influence of physical and chemical methods of enhanced oil recovery in formation microflora and properties of crude oil

    Shcherbakova, A. G.; Altunina, L. K.; Svarovskaya, L. I.; Ovsyannikova, V. S.; Filatov, D. A.; Chuikina, D. I.

    2015-10-01

    The results of the analyzes of crude oil and produced water from wells in the areas of pilot testing of new flow deflection and oil-displacing Compounds developed in the Institute of Petroleum Chemistry SB RAS. It was found that changes in the properties and Compound of the oil and water mainly occur in the redistribution of filtration flows and integration in the development of the previously unwashed areas, as well as in washing off the residual heavy oil from the reservoir rock, and in some wells - due to formation biocenosis, contributing to desorption of oil from the rock.

  14. Development of a bone tissue-engineered construct to enhance new bone formation in revision total hip replacement

    García Gareta, E.

    2012-01-01

    The main issue associated with revision total hip replacements (rTHRs) is how to generate new bone and restore bone stock for fixation of the revision stem. Bone tissue engineering (BTE) seeks the generation of constructs ex vivo in order to replace damaged or lost bone. The aim of this thesis was to develop a bone tissue-engineered construct with a calcium-phosphate (CaP) coated porous metal scaffold seeded throughout its structure with mesenchymal stem cells (MSCs) in order to enhance new b...

  15. Enhancement of CO(3-2)/CO(1-0) ratios and star formation efficiencies in supergiant H II regions

    We present evidence that super giant H II regions (GHRs) and other disk regions of the nearby spiral galaxy, M33, occupy distinct locations in the correlation between molecular gas, ΣH2, and the star formation rate surface density, ΣSFR. This result is based on wide-field and high-sensitivity CO(3-2) observations at 100 pc resolution. Star formation efficiencies (SFEs), defined as ΣSFR/ΣH2, in GHRs are found to be ∼1 dex higher than in other disk regions. The CO(3-2)/CO(1-0) integrated intensity ratio, R 3-2/1-0, is also higher than the average over the disk. Such high SFEs and R 3-2/1-0 can reach the values found in starburst galaxies, which suggests that GHRs may be the elements building up a larger-scale starburst region. Three possible contributions to high SFEs in GHRs are investigated: (1) the I CO-N(H2) conversion factor, (2) the dense gas fraction traced by R 3-2/1-0, and (3) the initial mass function (IMF). We conclude that these starburst-like properties in GHRs can be interpreted by a combination of both a top-heavy IMF and a high dense gas fraction, but not by changes in the I CO-N(H2) conversion factor.

  16. Enhancement of CO(3-2)/CO(1-0) ratios and star formation efficiencies in supergiant H II regions

    Miura, Rie E.; Espada, Daniel; Komugi, Shinya; Nakanishi, Kouichiro; Sawada, Tsuyoshi; Fujii, Kosuke; Kawabe, Ryohei [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Kohno, Kotaro [Institute of Astronomy, School of Science, The University of Tokyo, Osawa, Mitaka, Tokyo 181-0015 (Japan); Tosaki, Tomoka [Joetsu University of Education, Yamayashiki-machi, Joetsu, Niigata 943-8512 (Japan); Hirota, Akihiko; Minamidani, Tetsuhiro [Nobeyama Radio Observatory, Minamimaki, Minamisaku, Nagano 384-1805 (Japan); Okumura, Sachiko K. [Department of Mathematical and Physical Sciences, Faculty of Science, Japan Woman' s University, Mejirodai 2-8-1, Bunkyo, Tokyo 112-8681 (Japan); Kuno, Nario [Department of Astronomical Science, The Graduate University for Advanced Studies (Sokendai), 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Muraoka, Kazuyuki; Onodera, Sachiko [Osaka Prefecture University, Gakuen 1-1, Sakai, Osaka 599-8531 (Japan); Kaneko, Hiroyuki, E-mail: rie.miura@nao.ac.jp [Department of Physics, Meisei University, Hino, Tokyo 191-8506 (Japan)

    2014-06-20

    We present evidence that super giant H II regions (GHRs) and other disk regions of the nearby spiral galaxy, M33, occupy distinct locations in the correlation between molecular gas, Σ{sub H{sub 2}}, and the star formation rate surface density, Σ{sub SFR}. This result is based on wide-field and high-sensitivity CO(3-2) observations at 100 pc resolution. Star formation efficiencies (SFEs), defined as Σ{sub SFR}/Σ{sub H{sub 2}}, in GHRs are found to be ∼1 dex higher than in other disk regions. The CO(3-2)/CO(1-0) integrated intensity ratio, R {sub 3-2/1-0}, is also higher than the average over the disk. Such high SFEs and R {sub 3-2/1-0} can reach the values found in starburst galaxies, which suggests that GHRs may be the elements building up a larger-scale starburst region. Three possible contributions to high SFEs in GHRs are investigated: (1) the I {sub CO}-N(H{sub 2}) conversion factor, (2) the dense gas fraction traced by R {sub 3-2/1-0}, and (3) the initial mass function (IMF). We conclude that these starburst-like properties in GHRs can be interpreted by a combination of both a top-heavy IMF and a high dense gas fraction, but not by changes in the I {sub CO}-N(H{sub 2}) conversion factor.

  17. CdS nanowires decorated with Cu2O nanospheres: Synthesis, formation process and enhanced photoactivity and stability

    Highlights: • Novel CdS/Cu2O heterostructural composites were synthesized by a two-step chemical method. • A formation process of CdS/Cu2O heterostructural composites. • The CdS/Cu2O heterostructural composites were found to have superior photocatalytic performance and stability. - Abstract: CdS/Cu2O heterostructural materials were successfully synthesized by a solvent-thermal process followed by a chemical bath deposition process. Structures and morphologies of the obtained CdS/Cu2O composites were characterized by XRD, SEM, and TEM; the experimental results indicate that the surface of CdS nanowires (NWs) is decorated with spherical Cu2O whose diameter ranges from 100 to 200 nm. Through crystal shape-evolution, the formation process of these hierarchical nanostructures was rationally proposed. Briefly, in the chemical bath deposition process, Cu(OH)2 colloids generate firstly, and then the colloids transform into nanobelts after adding ascorbic acid (AA). With the reaction time further increasing, nanobelts aggregate together to form the hierarchical nanospheres on the surface of CdS NWs. The photoactivity of CdS/Cu2O composite for methyl orange (MO) photodegradation was investigated in detail. The obtained high photocatalytic efficiency can be attributed to the heterojunction structure, which results in the efficient separation of photo-generated electrons and holes

  18. Enhanced Light Emission due to Formation of Semi-polar InGaN/GaN Multi-quantum Wells.

    Zhao, Wan-Ru; Weng, Guo-En; Wang, Jian-Yu; Zhang, Jiang-Yong; Liang, Hong-Wei; Sekiguchi, Takashi; Zhang, Bao-Ping

    2015-12-01

    InGaN/GaN multi-quantum wells (MQWs) are grown on (0001) sapphire substrates by metal organic chemical vapor deposition (MOCVD) with special growth parameters to form V-shaped pits simultaneously. Measurements by atomic force microscopy (AFM) and transmission electron microscopy (TEM) demonstrate the formation of MQWs on both (0001) and ([Formula: see text]) side surface of the V-shaped pits. The latter is known to be a semi-polar surface. Optical characterizations together with theoretical calculation enable us to identify the optical transitions from these MQWs. The layer thickness on ([Formula: see text]) surface is smaller than that on (0001) surface, and the energy level in the ([Formula: see text]) semi-polar quantum well (QW) is higher than in the (0001) QW. As the sample temperature is increased from 15 K, the integrated cathodoluminescence (CL) intensity of (0001) MQWs increases first and then decreases while that of the ([Formula: see text]) MQWs decreases monotonically. The integrated photoluminescence (PL) intensity of (0001) MQWs increases significantly from 15 to 70 K. These results are explained by carrier injection from ([Formula: see text]) to (0001) MQWs due to thermal excitation. It is therefore concluded that the emission efficiency of (0001) MQWs at high temperatures can be greatly improved due to the formation of semi-polar MQWs. PMID:26625883

  19. Chemokine Signaling Enhances CD36 Responsiveness toward Oxidized Low-Density Lipoproteins and Accelerates Foam Cell Formation

    Harikesh S. Wong

    2016-03-01

    Full Text Available Excessive uptake of oxidized low-density lipoproteins (oxLDL by macrophages is a fundamental characteristic of atherosclerosis. However, signals regulating the engagement of these ligands remain elusive. Using single-molecule imaging, we discovered a mechanism whereby chemokine signaling enhanced binding of oxLDL to the scavenger receptor, CD36. By activating the Rap1-GTPase, chemokines promoted integrin-mediated adhesion of macrophages to the substratum. As a result, cells exhibited pronounced remodeling of the cortical actin cytoskeleton that increased CD36 clustering. Remarkably, CD36 clusters formed predominantly within actin-poor regions of the cortex, and these regions were primed to engage oxLDL. In accordance with enhanced ligand engagement, prolonged exposure of macrophages to chemokines amplified the accumulation of esterified cholesterol, thereby accentuating the foam cell phenotype. These findings imply that the activation of integrins by chemokine signaling exerts feedforward control over receptor clustering and effectively alters the threshold for cells to engage ligands.

  20. Studies on the enhancement of solid electrolyte interphase formation on graphitized anodes in LiX-carbonate based electrolytes using Lewis acid additives for lithium-ion batteries

    Li, L. F.; Xie, B.; Lee, H. S.; Li, H.; Yang, X. Q.; McBreen, J.; Huang, X. J.

    The new electrolyte systems utilizing one type of Lewis acids, the boron based anion receptors (BBARs) with LiF, Li 2O, or Li 2O 2 in carbonate solutions have been developed and reported by us. These systems open up a new approach in developing non-aqueous electrolytes with higher operating voltage and less moisture sensitivity for lithium-ion batteries. However, the formation of a stable solid electrolyte interphase (SEI) layer on the graphitized anodes is a serious problem needs to be solved for these new electrolyte systems, especially when propylene carbonate (PC) is used as a co-solvent. Using lithium bis(oxalato)borate (LiBOB) as an additives, the SEI layer formation on mesophase carbon microbeads (MCMB) anode is significantly enhanced in these new electrolytes containing boron-based anion receptors, such as tris(pentafluorophenyl) borane, and lithium salt such as LiF, or lithium oxides such as Li 2O or Li 2O 2 in PC and dimethyl carbonate (DMC) solvents. The cells using these electrolytes and MCMB anodes cycled very well and the PC co-intercalation was suppressed. Fourier transform infrared spectroscopy (FTIR) studies show that one of the electrochemical decomposition products of LiBOB, lithium carbonate (Li 2CO 3), plays a quite important role in the stablizing SEI layer formation.

  1. Sulfur (S)-induced enhancement of iron plaque formation in the rhizosphere reduces arsenic accumulation in rice (Oryza sativa L.) seedlings

    The effects of two sulfur (S) sources (SO42-, S0), and three rates of S application (0, 30, 120 mg S/kg) on the formation of iron plaque in the rhizosphere, and on the root surface of rice, and As (arsenic) uptake into rice (Oryza sativa L.) were studied in a combined soil-sand culture experiment. Significant differences in As uptake into rice between +S and -S treatments were observed in relation to S sources, and rates of S application. Concentrations of As in rice shoots decreased with increasing rates of S application. The mechanism could be ascribed to sulfur, induced the formation of iron plaque, since concentrations of Fe in iron plaque on quartz sands in the rhizosphere, and on the root surface of rice increased with increasing rates of S application. The results suggest that sulfur fertilization may be important for the development approaches to reducing As accumulation in rice. - Sulfur-induced enhancement of iron plaque formation on the root surface of rice

  2. Correlation between optical properties and Si nanocrystal formation of Si-rich Si oxide films prepared by plasma-enhanced chemical vapor deposition

    We have investigated the phase separation and silicon nanocrystal (Si NC) formation in correlation with the optical properties of Si suboxide (SiO x, 0 x films were deposited by plasma-enhanced chemical vapor deposition at different nitrous oxide/silane (N2O/SiH4) flow ratios. The as-deposited films show increased Si concentration with decreasing N2O/SiH4 flow ratio, while the deposition rate and surface roughness have strong correlations with the flow ratio in the N2O/SiH4 reaction. After thermal annealing at temperatures above 1000 deg. C, Fourier transform infrared spectroscopy, Raman spectroscopy, and transmission electron microscopy manifest the progressive phase separation and continuous growth of crystalline-Si (c-Si) NCs in the SiO x films with increasing annealing temperature. We observe a transition from multiple-peak to single peak of the strong red-range photoluminescence (PL) with increasing Si concentration and annealing temperature. The appearance of the single peak in the PL is closely related to the c-Si NC formation. The PL also redshifts from ∼1.9 to 1.4 eV with increasing Si concentration and annealing temperature (i.e., increasing NC size). The good agreements of the PL evolution with NC formation and the PL peak energy with NC size distribution support the quantum confinement model

  3. Red meat enhances the colonic formation of the DNA adduct O6-carboxymethyl guanine: implications for colorectal cancer risk.

    Lewin, Michelle H; Bailey, Nina; Bandaletova, Tanya; Bowman, Richard; Cross, Amanda J; Pollock, Jim; Shuker, David E G; Bingham, Sheila A

    2006-02-01

    Red meat is associated with increased risk of colorectal cancer and increases the endogenous formation of N-nitrosocompounds (NOC). To investigate the genotoxic effects of NOC arising from red meat consumption, human volunteers were fed high (420 g) red meat, vegetarian, and high red meat, high-fiber diets for 15 days in a randomized crossover design while living in a volunteer suite, where food was carefully controlled and all specimens were collected. In 21 volunteers, there was a consistent and significant (P vegetarian diet as measured by apparent total NOC (ATNC) in feces. In colonic exfoliated cells, the percentage staining positive for the NOC-specific DNA adduct, O(6)-carboxymethyl guanine (O(6)CMG) was significantly (P colorectal cancer. PMID:16452248

  4. Low temperatures enhance organic nitrate formation: evidence from observations in the 2012 Uintah Basin Winter Ozone Study

    L. Lee

    2014-06-01

    Full Text Available Nitrogen dioxide (NO2 and total alkyl nitrates (ΣANs were measured using thermal dissociation laser induced fluorescence during the 2012 Uintah Basin Winter Ozone Study (UBWOS in Utah, USA. The observed NO2 concentration was highest before sunrise and lowest in the late afternoon, suggestive of a persistent local source of NO2 coupled with turbulent mixing out of the boundary layer. In contrast, ΣANs co-varied with solar radiation with a noontime maximum, indicating that local photochemical production combined with rapid mixing and/or deposition was the dominant factor in determining the ΣAN concentrations. We calculate that ΣANs were a large fraction (~60% of the HOx free radical chain termination and show that the temperature dependence of the alkyl nitrate yields enhances the role of ΣANs in local chemistry during winter by comparison to what would occur at the warmer temperatures of summer.

  5. TEI-3313, a novel prostaglandin A1 derivative, prevents bone loss and enhances bone formation in immobilized male rats.

    Ohta, T; Azuma, Y; Kanatani, H; Kiyoki, M; Koshihara, Y

    1995-10-01

    The effect of a novel prostaglandin A1 derivative, TEI-3313, with the chemical structure 5-[(Z,2E)-4,7-dihydroxy-2-heptenyridene]-4-hydroxy- 2-methylthio-4-(4-phenoxybutyl)-2-cyclopentenone, on bone mineral content was investigated. Seven-week-old Sprague-Dawley rats in which the right hindlimbs were immobilized by sciatic nerve dissection received 1, 10, 100 or 500 micrograms of TEI-3313/kg/day, i.p., for 6 weeks. Control animals were operated on but received vehicle only. Bone mineral content of the femur was measured by single-photon absorptiometry, and biochemical parameters were analyzed. Histomorphometric observations were performed on the proximal metaphysial sections of the tibiae. The administration of up to 500 micrograms/kg of TEI-3313 to rats had no effect on body weight or on serum calcium, inorganic phosphorus and 1 alpha,25 dihydroxy vitamin D3 levels. Immobilization decreased the ash content, calcium content and total bone mineral content of the femur compared with nonimmobilization (unoperated femur). With TEI-3313 administration, changes in these parameters in the immobilized femur were prevented almost to the levels of the nonimmobilized femur, in a dose-dependent manner. The enhancement of bone mineral content was remarkable in the midshaft of the femur. TEI-3313 enhanced ash and calcium content and total bone mineral content in nonimmobilized femurs. Microradiograms showed that TEI-3313, unlike pamidronate and 17 beta-estradiol, had little inhibitory effect on trabecular bone resorption in the proximal portion of the tibia. TEI-3313 not only prevented the bone loss induced by immobilization but also increased bone mass in the nonimmobilized femurs without affecting the levels of 1 alpha,25 dihydroxy vitamin D3.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7562584

  6. Enhanced Star Formation of Less Massive Galaxies in a Proto-Cluster at z=2.5

    Hayashi, Masao; Tanaka, Ichi; Shimakawa, Rhythm; Koyama, Yusei; Tadaki, Ken-ichi; Suzuki, Tomoko L; Yamamoto, Moegi

    2016-01-01

    We investigate a correlation between star-formation rate (SFR) and stellar mass for Halpha emission line galaxies (HAEs) in one of the richest proto-clusters ever known at z~2.5, USS 1558-003 proto-cluster. This study is based on a 9.7-hour narrow-band imaging data with MOIRCS on the Subaru telescope. We are able to construct a sample, in combination with additional H-band data taken with WFC3 on Hubble Space Telescope (HST), of 100 HAEs reaching the dust-corrected SFRs down to 3 Msun/yr and the stellar masses down to $10^{8.0}$ Msun. We find that while the star-forming galaxies with >$10^{9.3}$ Msun are located on the universal SFR-mass main sequence irrespective of the environment, less massive star-forming galaxies with <$10^{9.3}$ Msun show a significant upward scatter from the main sequence in this proto-cluster. This suggests that some less massive galaxies are in a starburst phase, although we do not know yet if this is due to environmental effects.

  7. GRB 980425 host: [CII], [OI] and CO lines reveal recent enhancement of star formation due to atomic gas inflow

    Michałowski, Michał J; Wardlow, J L; Karska, A; Messias, H; van der Werf, P; Hunt, L K; Baes, M; Castro-Tirado, A J; Gentile, G; Hjorth, J; Floc'h, E Le; Martinez, R Perez; Guelbenzu, A Nicuesa; Rasmussen, J; Rizzo, J R; Rossi, A; Sanchez-Portal, M; Schady, P; Sollerman, J; Xu, D

    2016-01-01

    We have recently suggested that gas accretion can be studied using host galaxies of gamma-ray bursts (GRBs). We obtained the first ever far-infrared (FIR) line observations of a GRB host, namely Herschel/PACS resolved [CII] 158 um and [OI] 63 um spectroscopy, as well as APEX CO(2-1) and ALMA CO(1-0) observations of the GRB 980425 host. It has elevated [CII]/FIR and [OI]/FIR ratios and higher values of star formation rate (SFR) derived from line ([CII], [OI], Ha) than from continuum (UV, IR, radio) indicators. [CII] emission exhibits a normal morphology, peaking at the galaxy center, whereas [OI] is concentrated close to the GRB position and the nearby Wolf-Rayet region. The high [OI] flux indicates high radiation field and gas density. The [CII]/CO luminosity ratio of the GRB 980425 host is close to the highest values found for local star-forming galaxies. Its CO-derived molecular gas mass is low given its SFR and metallicity, but the [CII]-derived molecular gas mass is close to the expected value. The [OI] a...

  8. A Novel HA/β-TCP-Collagen Composite Enhanced New Bone Formation for Dental Extraction Socket Preservation in Beagle Dogs

    Ko-Ning Ho

    2016-03-01

    Full Text Available Past studies in humans have demonstrated horizontal and vertical bone loss after six months following tooth extraction. Many biomaterials have been developed to preserve bone volume after tooth extraction. Type I collagen serves as an excellent delivery system for growth factors and promotes angiogenesis. Calcium phosphate ceramics have also been investigated because their mineral chemistry resembles human bone. The aim of this study was to compare the performance of a novel bioresorbable purified fibrillar collagen and hydroxyapatite/β-tricalcium phosphate (HA/β-TCP ceramic composite versus collagen alone and a bovine xenograft-collagen composite in beagles. Collagen plugs, bovine graft-collagen composite and HA/β-TCP-collagen composite were implanted into the left and right first, second and third mandibular premolars, and the fourth molar was left empty for natural healing. In total, 20 male beagle dogs were used, and quantitative and histological analyses of the extraction ridge was done. The smallest width reduction was 19.09% ± 8.81% with the HA/β-TCP-collagen composite at Week 8, accompanied by new bone formation at Weeks 4 and 8. The HA/β-TCP-collagen composite performed well, as a new osteoconductive and biomimetic composite biomaterial, for socket bone preservation after tooth extraction.

  9. Nanosized Hydroxyapatite Coating on PEEK Implants Enhances Early Bone Formation: A Histological and Three-Dimensional Investigation in Rabbit Bone

    Pär Johansson

    2015-06-01

    Full Text Available Polyether ether ketone (PEEK has been frequently used in spinal surgery with good clinical results. The material has a low elastic modulus and is radiolucent. However, in oral implantology PEEK has displayed inferior ability to osseointegrate compared to titanium materials. One idea to reinforce PEEK would be to coat it with hydroxyapatite (HA, a ceramic material of good biocompatibility. In the present study we analyzed HA-coated PEEK tibial implants via histology and radiography when following up at 3 and 12 weeks. Of the 48 implants, 24 were HA-coated PEEK screws (test and another 24 implants served as uncoated PEEK controls. HA-coated PEEK implants were always osseointegrated. The total bone area (BA was higher for test compared to control implants at 3 (p < 0.05 and 12 weeks (p < 0.05. Mean bone implant contact (BIC percentage was significantly higher (p = 0.024 for the test compared to control implants at 3 weeks and higher without statistical significance at 12 weeks. The effect of HA-coating was concluded to be significant with respect to early bone formation, and HA-coated PEEK implants may represent a good material to serve as bone anchored clinical devices.

  10. Enhanced reactivity of hydroxylated polycyclic aromatic hydrocarbons to birnessite in soil: reaction kinetics and nonextractable residue formation.

    Jung, Jae-Woong; Lee, Seunghwan; Ryu, Hyerim; Nam, Kyoungphile; Kang, Ki-Hoon

    2008-05-01

    Phenanthrene and pyrene were not transformed by birnessite (delta-MnO2) in the presence of phenol. The phenoxy radicals generated from phenol by birnessite did not act as a mediator for polycyclic aromatic hydrocarbon radical reaction under the studied conditions. In contrast, 9-hydroxyphenanthrene and 1-hydroxypyrene were remarkably sensitive to birnessite. The disappearance patterns of the test compounds both in the aqueous phase and soil followed first-order kinetics, with a linear relationship found between the rate constants and the surface area of birnessite. Moreover, the data indicated that the reaction was faster in the presence of soil than in the aqueous phase probably because of the presence of hydroxyl groups in soil organic matter. Sequential solvent extraction was not successful in the recovery of 9-hydroxyphenanthrene from the birnessite-treated soil samples, and capillary electrophoresis data suggest the formation of nonextractable residues of the compound in soil. In addition, the acute toxicity determined by Microtox declined approximately 8.3 times in the soil samples treated with birnessite compared to untreated samples, demonstrating that the toxic compound was no longer present as its parent form. PMID:18419188

  11. Collagen immobilization of multi-layered BCP-ZrO2 bone substitutes to enhance bone formation

    Graphical abstract: - Highlights: • Col-BCP-ZrO. • Collagen fibers were formed and attached firmly on the surface of BCP-ZrO. • Highly interconnected but uniform porosity were obtained. • High biocompatible, strength scaffolds and new bone were evident in Col-BCP-ZrO2. - Abstract: A porous microstructure of multi-layered BCP-ZrO2 bone substitutes was fabricated using the sponge replica method in which the highly interconnected structure was immobilized with collagen via ethyl(dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide crosslinking. Their struts are combined with a three-layered BCP/BCP-ZrO2/ZrO2 microstructure. Collagen fibers were firmly attached to the strut surface of the BCP-ZrO2 scaffolds. With control of the three-layered microstructure and collagen immobilization, the compressive strength of the scaffolds increased significantly to 6.8 MPa compared to that of the monolithic BCP scaffolds (1.3 MPa). An in vitro study using MTT, confocal observation, and real-time polymer chain reaction analysis demonstrated that the proliferation and differentiation of the pre-osteoblast-like MC3T3-E1 cells was improved due to the collagen incorporation. Remarkable enhancement of bone regeneration was observed without any immunological reaction in the femurs of rabbits during 1 and 5 months of implantation. Furthermore, the interfaces between new bone and the scaffold struts bonded directly without any gaps

  12. Collagen immobilization of multi-layered BCP-ZrO{sub 2} bone substitutes to enhance bone formation

    Linh, Nguyen Thuy Ba [Department of Regenerative Medicine, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of); Institute of Tissue Regeneration, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of); Jang, Dong-Woo [Department of Regenerative Medicine, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of); Lee, Byong-Taek, E-mail: lbt@sch.ac.kr [Department of Regenerative Medicine, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of); Institute of Tissue Regeneration, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of)

    2015-08-01

    Graphical abstract: - Highlights: • Col-BCP-ZrO. • Collagen fibers were formed and attached firmly on the surface of BCP-ZrO. • Highly interconnected but uniform porosity were obtained. • High biocompatible, strength scaffolds and new bone were evident in Col-BCP-ZrO{sub 2}. - Abstract: A porous microstructure of multi-layered BCP-ZrO{sub 2} bone substitutes was fabricated using the sponge replica method in which the highly interconnected structure was immobilized with collagen via ethyl(dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide crosslinking. Their struts are combined with a three-layered BCP/BCP-ZrO{sub 2}/ZrO{sub 2} microstructure. Collagen fibers were firmly attached to the strut surface of the BCP-ZrO{sub 2} scaffolds. With control of the three-layered microstructure and collagen immobilization, the compressive strength of the scaffolds increased significantly to 6.8 MPa compared to that of the monolithic BCP scaffolds (1.3 MPa). An in vitro study using MTT, confocal observation, and real-time polymer chain reaction analysis demonstrated that the proliferation and differentiation of the pre-osteoblast-like MC3T3-E1 cells was improved due to the collagen incorporation. Remarkable enhancement of bone regeneration was observed without any immunological reaction in the femurs of rabbits during 1 and 5 months of implantation. Furthermore, the interfaces between new bone and the scaffold struts bonded directly without any gaps.

  13. In vitro inhibition and enhancement of liver microsomal S-777469 metabolism by long-chain fatty acids and serum albumin: insight into in vitro and in vivo discrepancy of metabolite formation in humans.

    Sekiguchi, Kazutaka; Kanazu, Takushi; Murayama, Norie; Yamazaki, Hiroshi; Yamaguchi, Yoshitaka

    2016-06-01

    1. It was previously demonstrated that 10% of S-777469, a cannabinoid receptor 2 selective agonist, is metabolized to its carboxylic acid metabolite (S-777469 5-carboxylic acid, 5-CA) in humans in vivo, while the formation of 5-CA is extremely low in human cryopreserved hepatocytes and liver microsomes (HLMs). In this study, factors causing the different metabolite formation rates of S-777469 in vitro and in vivo were investigated. 2. Formation of 5-CA and S-777469 5-hydroxymethyl (5-HM), a precursor metabolite of 5-CA, was catalyzed by CYP2C9. Arachidonic acid, α-linolenic acid, oleic acid and myristic acid, which have been reported to exist in liver microsomes, inhibited S-777469 oxidation by CYP2C9, but serum albumin enhanced this reactions. 3. The IC50 values of these fatty acids for 5-CA formation from 5-HM were lower than those of 5-HM formation from S-777469. Serum albumin extensively enhanced 5-CA formation from 5-HM in comparison to 5-HM formation from S-777469. 4. CYP2C9 was the enzyme responsible for S-777469 oxidation in human livers. The suppressive effects of several fatty acids and enhancing action of serum albumin in vitro are likely to be the causal factors for the apparently different rates of in vitro and in vivo metabolite formation of S-777469. PMID:26677906

  14. The mycotoxin zearalenone enhances cell proliferation, colony formation and promotes cell migration in the human colon carcinoma cell line HCT116.

    Abassi, Haila; Ayed-Boussema, Imen; Shirley, Sarah; Abid, Salwa; Bacha, Hassen; Micheau, Olivier

    2016-07-01

    Zearalenone (ZEN) and Aflatoxin B1 (AFB1) are fungal secondary metabolites produced by Fusarium and Aspergillus genera, respectively. These mycotoxins are found world-wide as corn and wheat contaminants. AFB1 is probably the most toxic and carcinogenic mycotoxin. It has been demonstrated to be mutagenic, genotoxic, and hepatocarcinogenic. ZEN is a non-steroidal estrogenic mycotoxin that displays hepatotoxicity, immunotoxicity and genotoxicity. Its mutagenic and carcinogenic properties have so far remained controversial and questionable. Using the colon carcinoma cell line HCT116, we will show here that ZEN, at low concentrations, enhances cell proliferation, increases colony formation and fastens cell migration after wound healing. The highest effect of ZEN was observed at a concentration 10 times lower as compared to AFB1. Our findings suggest thus that this mycotoxin exhibits carcinogenesis-like properties in HCT116 cells. PMID:27084041

  15. Apigenin-induced apoptosis is enhanced by inhibition of autophagy formation in HCT116 human colon cancer cells.

    Lee, Yujin; Sung, Bokyung; Kang, Yong Jung; Kim, Dong Hwan; Jang, Jung-Yoon; Hwang, Seong Yeon; Kim, Minjung; Lim, Hyun Sook; Yoon, Jeong-Hyun; Chung, Hae Young; Kim, Nam Deuk

    2014-05-01

    Apigenin (4',5,7-trihydroxyflavone) is a natural flavonoid, shown to have chemopreventive and/or anticancer properties in a variety of human cancer cells. The involvement of autophagy in apigenin-induced apoptotic cell death of HCT116 human colon cancer cells was investigated. Apigenin induced suppression of cell growth in a concentration-dependent manner in HCT116 cells. Flow cytometric analyses indicated that apigenin resulted in G2/M phase arrest. This flavone also suppressed the expression of both cyclin B1 and its activating partners, Cdc2 and Cdc25c, whereas the expression of cell cycle inhibitors, such as p53 and p53-dependent p21(CIP1/WAF1), was increased after apigenin treatment. Apigenin induced poly (ADP-ribose) polymerase (PARP) cleavage and decreased the levels of procaspase-8, -9 and -3. In addition, the apigenin-treated cells exhibited autophagy, as characterized by the appearance of autophagosomes under fluorescence microscopy and the accumulation of acidic vesicular organelles by flow cytometry. Furthermore, the results of the western blot analysis revealed that the levels of LC3-II, the processed form of LC3-I, was increased by apigenin. Treatment with the autophagy inhibitor 3-methyladenine (3-MA) significantly enhanced the apoptosis induced by apigenin, which was accompanied by an increase in the levels of PARP cleavage. These results indicate that apigenin has apoptosis- and autophagy-inducing effects in HCT116 colon cancer cells. Autophagy plays a cytoprotective role in apigenin-induced apoptosis, and the combination of apigenin and an autophagy inhibitor may be a promising strategy for colon cancer control. PMID:24626522

  16. Controlled synthesis of magnetic iron oxides@SnO2 quasi-hollow core-shell heterostructures: formation mechanism, and enhanced photocatalytic activity

    Wu, Wei; Zhang, Shaofeng; Ren, Feng; Xiao, Xiangheng; Zhou, Juan; Jiang, Changzhong

    2011-11-01

    Iron oxide/SnO2 magnetic semiconductor core-shell heterostructures with high purity were synthesized by a low-cost, surfactant-free and environmentally friendly hydrothermal strategy via a seed-mediated method. The morphology and structure of the hybrid nanostructures were characterized by means of high-resolution transmission electron microscopy and X-ray diffraction. The morphology evolution investigations reveal that the Kirkendall effect directs the diffusion and causes the formation of iron oxide/SnO2 quasi-hollow particles. Significantly, the as-obtained iron oxides/SnO2 core-shell heterostructures exhibited enhanced visible light or UV photocatalytic abilities, remarkably superior to as-used α-Fe2O3 seeds and commercial SnO2 products, mainly owing to the effective electron hole separation at the iron oxides/SnO2 interfaces.Iron oxide/SnO2 magnetic semiconductor core-shell heterostructures with high purity were synthesized by a low-cost, surfactant-free and environmentally friendly hydrothermal strategy via a seed-mediated method. The morphology and structure of the hybrid nanostructures were characterized by means of high-resolution transmission electron microscopy and X-ray diffraction. The morphology evolution investigations reveal that the Kirkendall effect directs the diffusion and causes the formation of iron oxide/SnO2 quasi-hollow particles. Significantly, the as-obtained iron oxides/SnO2 core-shell heterostructures exhibited enhanced visible light or UV photocatalytic abilities, remarkably superior to as-used α-Fe2O3 seeds and commercial SnO2 products, mainly owing to the effective electron hole separation at the iron oxides/SnO2 interfaces. Electronic supplementary information (ESI) available: TEM and HRTEM images of hematite seeds and iron oxide/SnO2 (12 h and 36 h). See DOI: 10.1039/c1nr10728c

  17. Nanocrystalline silicon and silicon quantum dots formation within amorphous silicon carbide by plasma enhanced chemical vapour deposition method controlling the Argon dilution of the process gases

    Structural and optical properties of the amorphous silicon carbide (a-SiC:H) thin films deposited by radio frequency plasma enhanced chemical vapour deposition method from a mixture of silane (SiH4) and methane (CH4) diluted in argon (Ar) have been studied with variation of Ar dilution from 94% to 98.4%. It is observed that nanocrystalline silicon starts to form within the a-SiC:H matrix by increasing the dilution to 96%. With further increase in Ar dilution to 98% formation of the silicon nanocrystals (nc-Si) with variable size is enhanced. The optical band gap (Eg) of the a-SiC:H film decreases from 2.0 eV to 1.9 eV with increase in Ar dilution from 96% to 98% as the a-SiC:H films gradually become Si rich. On increasing the Ar dilution further to 98.4% leads to the appearance of crystalline silicon quantum dots (c-Si q-dots) of nearly uniform size of 3.5 nm. The quantum confinement effect is apparent from the sharp increase in the Eg value to 2.6 eV. The phase transformation phenomenon from nc-Si within the a-SiC:H films to Si q-dot were further studied by high resolution transmission electron microscopy and the grazing angle X-ray diffraction spectra. A relaxation in the lattice strain has been observed with the formation of Si q-dots.

  18. Potential for Carbon Dioxide Sequestration and Enhanced Oil Recovery in the Vedder Formation, Greeley Field, San Joaquin Valley, California.

    Jameson, S.

    2015-12-01

    Most scientists agree that greenhouse gases (GHG) such as carbon dioxide (CO2), Methane (CH4), and nitrous oxide (N2O) are major contributors to the global warming trend and climate change. One effort to mitigate anthropogenic sourced CO2 is through carbon capture and sequestration. Depleted oil and gas reservoirs due to their known trapping capability, in-place infrastructure, and proximity to carbon emission sources are good candidates for possible CO2 storage. The Vedder formation is one of three reservoirs identified in the San Joaquin Basin that meets standards for possible storage. An analysis of net fluid production data (produced minus injected) from discovery to the present is used to determine the reservoir volume available for CO2 storage. Data regarding reservoir pressure response to injection and production of fluids include final shut-in pressures from drill stem test, static bottom-hole pressure measurements from well completion histories, and idle well fluid level measurements for recent pressure data. Proprietary experimental pressure, volume and temperature data (PVT), gas oil ratios (GOR), well by well permeability, porosity, and oil gravity, and relative permeability and perforation intervals are used to create static and dynamic multiphase fluid flow models. All data collected was logged and entered into excel spreadsheets and mapping software to create subsurface structure, reservoir thickness and pressure maps, cross sections, production/injection charts on a well-by-well basis, and both static and dynamic flow models. This data is used to determine storage capacity and the amount of pressure variance within the field to determine how the reservoir will react to CO2 injection and to gain insight into the subsurface fluid movement of CO2. Results indicate a homogenous field with a storage capacity of approximately 26 Million Metric Tons of CO2. Analysis of production by stream and pressure change through time indicates a strong water drive

  19. Ethanolic Extract of Butea monosperma Leaves Elevate Blood Insulin Level in Type 2 Diabetic Rats, Stimulate Insulin Secretion in Isolated Rat Islets, and Enhance Hepatic Glycogen Formation

    Mehdi Bin Samad

    2014-01-01

    Full Text Available We measured a vast range of parameters, in an attempt to further elucidate previously claimed antihyperglycemic activity of Butea monosperma. Our study clearly negates the possibility of antidiabetic activity by inhibited gastrointestinal enzyme action or by reduced glucose absorption. Reduction of fasting and postprandial glucose level was reconfirmed (P<0.05. Improved serum lipid profile via reduced low density lipoprotein (LDL, cholesterol, triglycerides (TG, and increased high density lipoprotein (HDL was also reestablished (P<0.05. Significant insulin secretagogue activity of B. monosperma was found in serum insulin assay of B. monosperma treated type 2 diabetic rats (P<0.01. This was further ascertained by our study on insulin secretion on isolated rat islets (P<0.05. Improved sensitivity of glucose was shown by the significant increase in hepatic glycogen deposition (P<0.05. Hence, we concluded that antihyperglycemic activity of B. monosperma was mediated by enhanced insulin secretion and enhanced glycogen formation in the liver.

  20. Bcl-2 enhances the formation of newborn striatal long-projection neurons in adult rat brain after a transient ischemic stroke

    Jian-Jun Guo; Fang Liu; Xiao Sun; Jun-Jie Huang; Ming Xu; Feng-Yan Sun

    2012-01-01

    Objective It has been reported that B-cell lymphoma 2 (Bcl-2) enhances neurogenesis as well as supporting axonal growth after injury.In the present study,we investigated whether Bcl-2 overexpression plays a role in the formation of newborn striatonigral projection neurons in the adult rat brain after transient middle cerebral artery occlusion (MCAO).Methods We infused human Bcl-2-expressing plasmid (pBcl-2) into the lateral ventricle immediately after 30 min of MCAO,injected 5'-bromodeoxyuridine (BrdU) intraperitoneally to label proliferative cells,and microinjected fluorogold (FG) into the substantia nigra at 11 weeks of reperfusion followed by multiple immunostaining of striatonigral projection neurons at 12 weeks.Results We found that pBcl-2 treatment significantly increased the number of newborn neurons (BrdU+-NeuN+) in the striatum ipsilateral to the MCAO.We further detected newborn striatonigral projection neurons (BrdU+-FG+-NeuN+) in the ipsilateral striatum at 12 weeks.More interestingly,the number of newborn striatonigral projection neurons (BrdU+-FG+) was significantly increased by pBcl-2 treatment compared to that by pEGFP,a control plasmid.Conclusion Taken together,we found that Bcl-2 overexpression in the brain enhanced the generation of newborn striatonigral projection neurons.This provides a potential strategy for promoting the reestablishment of neural networks and brain repair after ischemic injury.

  1. Walk-Off-Induced Modulation Instability, Temporal Pattern Formation, and Frequency Comb Generation in Cavity-Enhanced Second-Harmonic Generation

    Leo, F.; Hansson, T.; Ricciardi, I.; De Rosa, M.; Coen, S.; Wabnitz, S.; Erkintalo, M.

    2016-01-01

    We derive a time-domain mean-field equation to model the full temporal and spectral dynamics of light in singly resonant cavity-enhanced second-harmonic generation systems. We show that the temporal walk-off between the fundamental and the second-harmonic fields plays a decisive role under realistic conditions, giving rise to rich, previously unidentified nonlinear behavior. Through linear stability analysis and numerical simulations, we discover a new kind of quadratic modulation instability which leads to the formation of optical frequency combs and associated time-domain dissipative structures. Our numerical simulations show excellent agreement with recent experimental observations of frequency combs in quadratic nonlinear media [Phys. Rev. A 91, 063839 (2015)]. Thus, in addition to unveiling a new, experimentally accessible regime of nonlinear dynamics, our work enables predictive modeling of frequency comb generation in cavity-enhanced second-harmonic generation systems. We expect our findings to have wide impact on the study of temporal and spectral dynamics in a diverse range of dispersive, quadratically nonlinear resonators.

  2. Enhanced photoelectrochemical performance of WO{sub 3}/Ti photoanode due to in situ formation of a thin interfacial composite layer

    Lee, Won Jae, E-mail: wjlee@keri.re.kr [Battery Research Center, Korea Electrotechnology Research Institute (KERI), Changwon 641-120 (Korea, Republic of); Shinde, Pravin S.; Go, Geun Ho; Doh, Chil Hoon [Battery Research Center, Korea Electrotechnology Research Institute (KERI), Changwon 641-120 (Korea, Republic of)

    2013-04-01

    Nanostructured WO{sub 3} thin films were prepared on titanium sheet substrates using a doctor blade technique. X-ray diffraction, Raman and field emission scanning electron microscopy studies revealed that the synthesized WO{sub 3} films are having monoclinic crystal structure, porous, polycrystalline with average grain size of ∼50 nm. The photoelectrochemical responses of WO{sub 3} films prepared on treated Ti sheets were recorded in 0.5 M H{sub 2}SO{sub 4} electrolyte under simulated 100 mW/cm{sup 2} illumination. WO{sub 3} film prepared on polished Ti sheet showed considerable enhancement in photocurrent as compared to WO{sub 3} films made on unpolished and pre-oxidized Ti sheets. These results suggest that in situ formation of a thin WO{sub x}–TiO{sub y} interfacial composite layer and improved adhesion of WO{sub 3} nanoparticles owing to increased reactive sites on polished Ti substrate play a significant role in enhancing the photoresponse. Such photoanodes are potential candidates in photoelectrochemical water splitting system for hydrogen generation.

  3. Protein recognition sites in polyomavirus enhancer: formation of a novel site for NF-1 factor in an enhancer mutant and characterization of a site in the enhancer D domain.

    M. CARUSO; Iacobini, C; Passananti, C; Felsani, A; Amati, P

    1990-01-01

    Polyomavirus mutants selected for modified host range exhibit DNA sequence alterations in the regulatory region, which consist mainly of duplications and/or deletions. Single base pair mutations have also been observed, which create or abolish DNA sequence motifs recognized by DNA-binding regulatory factors. The present work deals with the molecular characterization of a Polyoma mutant (PyNB11/1), selected for its high efficiency of growth in neuroblastoma cells. The enhancer region of PyNB11...

  4. Assessing the osteoblast transcriptome in a model of enhanced bone formation due to constitutive Gs–G protein signaling in osteoblasts

    G protein-coupled receptor (GPCR) signaling in osteoblasts (OBs) is an important regulator of bone formation. We previously described a mouse model expressing Rs1, an engineered constitutively active Gs-coupled GPCR, under the control of the 2.3 kb Col I promoter. These mice showed a dramatic age-dependent increase in trabecular bone of femurs. Here, we further evaluated the effects of enhanced Gs signaling in OBs on intramembranous bone formation by examining calvariae of 1- and 9-week-old Col1(2.3)/Rs1 mice and characterized the in vivo gene expression specifically occurring in osteoblasts with activated Gs G protein-coupled receptor signaling, at the cellular level rather than in a whole bone. Rs1 calvariae displayed a dramatic increase in bone volume with partial loss of cortical structure. By immunohistochemistry, Osterix was detected in cells throughout the inter-trabecular space while Osteocalcin was expressed predominantly in cells along bone surfaces, suggesting the role of paracrine mediators secreted from OBs driven by 2.3 kb Col I promoter could influence early OB commitment, differentiation, and/or proliferation. Gene expression analysis of calvarial OBs revealed that genes affected by Rs1 signaling include those encoding proteins important for cell differentiation, cytokines and growth factors, angiogenesis, coagulation, and energy metabolism. The set of Gs-GPCRs and other GPCRs that may contribute to the observed skeletal phenotype and candidate paracrine mediators of the effect of Gs signaling in OBs were also determined. Our results identify novel detailed in vivo cellular changes of the anabolic response of the skeleton to Gs signaling in mature OBs. - Highlights: • OB expression of an engineered Gs-coupled receptor dramatically increases bone mass. • We investigated the changes in gene expression in vivo in enhanced OB Gs signaling. • Genes in cell cycle and transcription were increased in enhanced OB Gs signaling. • GPCRs and paracrine

  5. Assessing the osteoblast transcriptome in a model of enhanced bone formation due to constitutive G{sub s}–G protein signaling in osteoblasts

    Wattanachanya, Lalita, E-mail: lalita_md@yahoo.com [Endocrine Research Unit, Veterans Affairs Medical Center and Departments of Medicine and Physiology, University of California, San Francisco, CA (United States); Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok (Thailand); Wang, Liping, E-mail: lipingwang05@yahoo.com [Endocrine Research Unit, Veterans Affairs Medical Center and Departments of Medicine and Physiology, University of California, San Francisco, CA (United States); Millard, Susan M., E-mail: susan.millard@mater.uq.edu.au [Endocrine Research Unit, Veterans Affairs Medical Center and Departments of Medicine and Physiology, University of California, San Francisco, CA (United States); Lu, Wei-Dar, E-mail: weidar_lu@yahoo.com [Endocrine Research Unit, Veterans Affairs Medical Center and Departments of Medicine and Physiology, University of California, San Francisco, CA (United States); O’Carroll, Dylan, E-mail: dylancocarroll@gmail.com [Endocrine Research Unit, Veterans Affairs Medical Center and Departments of Medicine and Physiology, University of California, San Francisco, CA (United States); Hsiao, Edward C., E-mail: Edward.Hsiao@ucsf.edu [Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Francisco, CA (United States); Conklin, Bruce R., E-mail: bconklin@gladstone.ucsf.edu [Gladstone Institute of Cardiovascular Disease, San Francisco, CA (United States); Department of Medicine, University of California, San Francisco, CA (United States); Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA (United States); Nissenson, Robert A., E-mail: Robert.Nissenson@ucsf.edu [Endocrine Research Unit, Veterans Affairs Medical Center and Departments of Medicine and Physiology, University of California, San Francisco, CA (United States)

    2015-05-01

    G protein-coupled receptor (GPCR) signaling in osteoblasts (OBs) is an important regulator of bone formation. We previously described a mouse model expressing Rs1, an engineered constitutively active G{sub s}-coupled GPCR, under the control of the 2.3 kb Col I promoter. These mice showed a dramatic age-dependent increase in trabecular bone of femurs. Here, we further evaluated the effects of enhanced G{sub s} signaling in OBs on intramembranous bone formation by examining calvariae of 1- and 9-week-old Col1(2.3)/Rs1 mice and characterized the in vivo gene expression specifically occurring in osteoblasts with activated G{sub s} G protein-coupled receptor signaling, at the cellular level rather than in a whole bone. Rs1 calvariae displayed a dramatic increase in bone volume with partial loss of cortical structure. By immunohistochemistry, Osterix was detected in cells throughout the inter-trabecular space while Osteocalcin was expressed predominantly in cells along bone surfaces, suggesting the role of paracrine mediators secreted from OBs driven by 2.3 kb Col I promoter could influence early OB commitment, differentiation, and/or proliferation. Gene expression analysis of calvarial OBs revealed that genes affected by Rs1 signaling include those encoding proteins important for cell differentiation, cytokines and growth factors, angiogenesis, coagulation, and energy metabolism. The set of G{sub s}-GPCRs and other GPCRs that may contribute to the observed skeletal phenotype and candidate paracrine mediators of the effect of G{sub s} signaling in OBs were also determined. Our results identify novel detailed in vivo cellular changes of the anabolic response of the skeleton to G{sub s} signaling in mature OBs. - Highlights: • OB expression of an engineered G{sub s}-coupled receptor dramatically increases bone mass. • We investigated the changes in gene expression in vivo in enhanced OB G{sub s} signaling. • Genes in cell cycle and transcription were increased in

  6. Host cell and expression engineering for development of an E. coli ketoreductase catalyst: Enhancement of formate dehydrogenase activity for regeneration of NADH

    Mädje Katharina

    2012-01-01

    Full Text Available Abstract Background Enzymatic NADH or NADPH-dependent reduction is a widely applied approach for the synthesis of optically active organic compounds. The overall biocatalytic conversion usually involves in situ regeneration of the expensive NAD(PH. Oxidation of formate to carbon dioxide, catalyzed by formate dehydrogenase (EC 1.2.1.2; FDH, presents an almost ideal process solution for coenzyme regeneration that has been well established for NADH. Because isolated FDH is relatively unstable under a range of process conditions, whole cells often constitute the preferred form of the biocatalyst, combining the advantage of enzyme protection in the cellular environment with ease of enzyme production. However, the most prominent FDH used in biotransformations, the enzyme from the yeast Candida boidinii, is usually expressed in limiting amounts of activity in the prime host for whole cell biocatalysis, Escherichia coli. We therefore performed expression engineering with the aim of enhancing FDH activity in an E. coli ketoreductase catalyst. The benefit resulting from improved NADH regeneration capacity is demonstrated in two transformations of technological relevance: xylose conversion into xylitol, and synthesis of (S-1-(2-chlorophenylethanol from o-chloroacetophenone. Results As compared to individual expression of C. boidinii FDH in E. coli BL21 (DE3 that gave an intracellular enzyme activity of 400 units/gCDW, co-expression of the FDH with the ketoreductase (Candida tenuis xylose reductase; XR resulted in a substantial decline in FDH activity. The remaining FDH activity of only 85 U/gCDW was strongly limiting the overall catalytic activity of the whole cell system. Combined effects from increase in FDH gene copy number, supply of rare tRNAs in a Rosetta strain of E. coli, dampened expression of the ketoreductase, and induction at low temperature (18°C brought up the FDH activity threefold to a level of 250 U/gCDW while reducing the XR activity by

  7. Basic polyamino acids rich in arginine, lysine, or ornithine cause both enhancement of and refractoriness to formation of endothelium-derived nitric oxide in pulmonary artery and vein.

    Ignarro, L J; Gold, M E; Buga, G M; Byrns, R E; Wood, K S; Chaudhuri, G; Frank, G

    1989-02-01

    The objective of this study was to elucidate the mechanism by which polyamino acids containing L-arginine, L-lysine or L-ornithine cause endothelium-dependent relaxation of bovine intrapulmonary artery and vein. Basic but not acidic or neutral polypeptides ranging in average molecular weights from 17 to 225 kDa elicited time- and concentration-dependent relaxation and cyclic GMP accumulation in precontracted rings of artery and vein by endothelium-dependent mechanisms. Vascular responses were markedly inhibited by oxyhemoglobin, methylene blue, or potassium. The basic polyamino acids stimulated the formation and/or release of an endothelium-derived relaxing factor (EDRF) identified as nitric oxide (NO) in perfused segments of both artery and vein as assessed by bioassay. The polyamino acids and A23187 released a similar endothelium-derived NO (EDNO) from artery and vein, as assessed by the similar half-life (3-5 seconds), antagonism by superoxide anion or oxyhemoglobin, enhancement by superoxide dismutase, and lack of influence by indomethacin. The basic polyamino acids elicited potent relaxant responses with EC50 values ranging from 3 x 10(-9) to 2 x 10(-7) M, and a direct correlation was obtained between molecular weight and relaxation potency irrespective of the basic amino acid incorporated. Prolonged contact of arterial or venous rings with basic polyamino acids resulted in the rapid development of marked refractoriness to relaxation and cyclic GMP formation on addition of polyamino acid. Moreover, refractoriness developed to the vascular responses of other endothelium-dependent vasodilators but not to glyceryl trinitrate or isoproterenol. The mechanism of refractory responses was attributed to interference with EDNO formation and release as assessed by bioassay and chemical assay. The hypothesis is forwarded that the basic polyamino acids serve as partial substrates for the enzyme system that catalyzes the conversion of L-arginine to NO. Prolonged contact

  8. SIMPL enhancement of tumor necrosis factor-α dependent p65-MED1 complex formation is required for mammalian hematopoietic stem and progenitor cell function.

    Weina Zhao

    Full Text Available Significant insight into the signaling pathways leading to activation of the Rel transcription factor family, collectively termed NF-κB, has been gained. Less well understood is how subsets of NF-κB-dependent genes are regulated in a signal specific manner. The SIMPL protein (signaling molecule that interacts with mouse pelle-like kinase is required for full Tumor Necrosis Factor-α (TNFα induced NF-κB activity. We show that SIMPL is required for steady-state hematopoiesis and the expression of a subset of TNFα induced genes whose products regulate hematopoietic cell activity. To gain insight into the mechanism through which SIMPL modulates gene expression we focused on the Tnf gene, an immune response regulator required for steady-state hematopoiesis. In response to TNFα SIMPL localizes to the Tnf gene promoter where it modulates the initiation of Tnf gene transcription. SIMPL binding partners identified by mass spectrometry include proteins involved in transcription and the interaction between SIMPL and MED1 was characterized in more detail. In response to TNFα, SIMPL is found in p65-MED1 complexes where SIMPL enhances p65/MED1/SIMPL complex formation. Together our results indicate that SIMPL functions as a TNFα-dependent p65 co-activator by facilitating the recruitment of MED1 to p65 containing transcriptional complexes to control the expression of a subset of TNFα-induced genes.

  9. In-situ formation of ion-association nanoparticles induced enhancements of resonance Rayleigh scattering intensities for quantitative analysis of trace Hg(2+) ions in environmental samples.

    Yang, Qingling; Liu, Jian; Li, Banglin; Hu, Xiaoli; Liu, Shaopu; Chen, Gangcai

    2016-10-01

    In this paper, Hg(2+) ions are demonstrated to form anionic [HgI4](2-) complexes after interacting with massive amount of I(-) ions. Subsequently, the addition of tetradecyl pyridyl bromide (TPB) can make [HgI4](2-) anionic complexes react with univalent tetradecyl pyridyl cationic ions (TP(+)), forming dispersed ion-association complexes (TP)2(HgI4). Due to the extrusion action of water and Van der Waals force, the hydrophobic ion-association complexes aggregate together, forming dispersed nanoparticles with an average size of about 8.5nm. Meanwhile, resonance Rayleigh scattering (RRS) intensity is apparently enhanced due to the formation of (TP)2(HgI4) ion-association nanoparticles, contributing to a novel technique for Hg(2+) detection. The wavelength of 365nm is chosen as a detection wavelength and several conditions affecting the RRS responses of Hg(2+) are optimized. Under the optimum condition, the developed method is used for the determination of Hg(2+) in aqueous solution and the detection limit is estimated to be 0.8ngmL(-1). Finally, the practical application of the developed method can be confirmed through the detections of Hg(2+) in waste and river water samples with satisfactory results. PMID:27235829

  10. Overexpression of gibberellin 20-oxidase1 from Pinus densiflora results in enhanced wood formation with gelatinous fiber development in a transgenic hybrid poplar.

    Park, Eung-Jun; Kim, Hyun-Tae; Choi, Young-Im; Lee, Chanhui; Nguyen, Van Phap; Jeon, Hyung-Woo; Cho, Jin-Seong; Funada, Ryo; Pharis, Richard P; Kurepin, Leonid V; Ko, Jae-Heung

    2015-11-01

    Gibberellins (GAs) are important regulators of plant shoot biomass growth, and GA 20-oxidase (GA20ox) is one of the major regulatory enzymes in the GA biosynthetic pathway. Previously, we showed that the expression levels of a putative GA20ox1 (i.e., PdGA20ox1) in stem tissue of 3-month-old seedlings of 12 families of Pinus densiflora were positively correlated with stem diameter growth across those same families growing in an even-aged 32-year-old pine forest (Park EJ, Lee WY, Kurepin LV, Zhang R, Janzen L, Pharis RP (2015) Plant hormone-assisted early family selection in Pinus densiflora via a retrospective approach. Tree Physiol 35:86-94). To further investigate the molecular function of this gene in the stem wood growth of forest trees, we produced transgenic poplar lines expressing PdGA20ox1 under the control of the 35S promoter (designated as 35S::PdGA20ox1). By age 3 months, most of the 35S::PdGA20ox1 poplar trees were showing an exceptional enhancement of stem wood growth, i.e., up to fourfold increases in stem dry weight, compared with the nontransformed control poplar plants. Significant increases in endogenous GA1, its immediate precursor (GA20) and its catabolite (GA8) in elongating internode tissue accompanied the increased stem growth in the transgenic lines. Additionally, the development of gelatinous fibers occurred in vertically grown stems of the 35S::PdGA20ox1 poplars. An analysis of the cell wall monosaccharide composition of the 35S::PdGA20ox1 poplars showed significant increases in xylose and glucose contents, indicating a qualitative increase in secondary wall depositions. Microarray analyses led us to find a total of 276 probe sets that were upregulated (using threefold as a threshold) in the stem tissues of 35S::PdGA20ox1 poplars relative to the controls. 'Cell organization or biogenesis'- and 'cell wall'-related genes were overrepresented, including many of genes that are involved in cell wall modification. Several transcriptional

  11. Expression of UME6, a Key Regulator of Candida albicans Hyphal Development, Enhances Biofilm Formation via Hgc1- and Sun41-Dependent Mechanisms

    Banerjee, Mohua; Uppuluri, Priya; Zhao, Xiang R.; Carlisle, Patricia L.; Vipulanandan, Geethanjali; Villar, Cristina C.; López-Ribot, José L.; Kadosh, David

    2013-01-01

    Biofilm formation is associated with the ability of Candida albicans, the major human fungal pathogen, to resist antifungal therapies and grow on tissues, catheters, and medical devices. In order to better understand the relationship between C. albicans morphology and biofilm formation, we examined biofilms generated in response to expression of UME6, a key filament-specific transcriptional regulator. As UME6 levels rise, C. albicans cells are known to transition from yeast to hyphae, and we ...

  12. Enhanced neointima formation following arterial injury in immune deficient Rag-1-/- mice is attenuated by adoptive transfer of CD8 T cells.

    Paul C Dimayuga

    Full Text Available T cells modulate neointima formation after arterial injury but the specific T cell population that is activated in response to arterial injury remains unknown. The objective of the study was to identify the T cell populations that are activated and modulate neointimal thickening after arterial injury in mice. Arterial injury in wild type C57Bl6 mice resulted in T cell activation characterized by increased CD4(+CD44(hi and CD8(+CD44(hi T cells in the lymph nodes and spleens. Splenic CD8(+CD25(+ T cells and CD8(+CD28(+ T cells, but not CD4(+CD25(+ and CD4(+CD28(+ T cells, were also significantly increased. Adoptive cell transfer of CD4(+ or CD8(+ T cells from donor CD8-/- or CD4-/- mice, respectively, to immune-deficient Rag-1-/- mice was performed to determine the T cell subtype that inhibits neointima formation after arterial injury. Rag-1-/- mice that received CD8(+ T cells had significantly reduced neointima formation compared with Rag-1-/- mice without cell transfer. CD4(+ T cell transfer did not reduce neointima formation. CD8(+ T cells from CD4-/- mice had cytotoxic activity against syngeneic smooth muscle cells in vitro. The study shows that although both CD8(+ T cells and CD4(+ T cells are activated in response to arterial injury, adoptive cell transfer identifies CD8(+ T cells as the specific and selective cell type involved in inhibiting neointima formation.

  13. Enhanced Historical Land-Use and Land-Cover Data Sets of the U.S. Geological Survey: polygon format files

    U.S. Geological Survey, Department of the Interior — This data set depicts land use and land cover from the 1970s and 1980s and has been previously published by the U.S. Geological Survey (USGS) in other file formats....

  14. Type 3 fimbriae, encoded by the conjugative plasmid pOLA52, enhance biofilm formation and transfer frequencies in Enterobacteriaceae strains

    Burmølle, Mette; Bahl, Martin Iain; Jensen, Lars Bogø;

    2008-01-01

    pathogenic, members of the family Enterobacteriaceae, including Klebsiella pneumoniae, Salmonella Typhimurium, Kluyvera sp. and Enterobacter aerogenes, pOLA52 facilitated increased biofilm formation. pOLA52 is believed to represent the first example of a conjugative plasmid encoding type 3 fimbriae...

  15. The Development and Implementation of a Web-Based Formative Peer Assessment System for Enhancing Students' Metacognitive Awareness and Performance in Ill-Structured Tasks

    Kim, Minjeong; Ryu, Jeeheon

    2013-01-01

    An assessment was conducted of a web-based formative peer assessment system (WFPAS) emphasizing learners' metacognitive awareness for their performance in ill-structured tasks. Results indicate that the WFPAS group achieved significantly higher scores for metacognitive awareness and performance in ill-structured tasks than the traditional…

  16. Enhanced Historical Land-Use and Land-Cover Data Sets of the U.S. Geological Survey: raster format files

    U.S. Geological Survey, Department of the Interior — This data set depicts land use and land cover from the 1970s and 1980s and has been previously published by the U.S. Geological Survey (USGS) in other file formats....

  17. Enhancement of hemolytic and catecholamine releasing activities of mastoparan by the dendrimeric formation; Masutoparan bunshi no jujoka ni yoru sekkekyu yoketsu sayo to katekoru amin hoshutsu sayo no kokasseika

    Kurita, Takashi; Kosemura, Yoshiko; Ito, Hisashi [Aoyama Gakuin University, Tokyo (Japan). Department of Chemistry; Kumakura, Konosuke [Sophia University, Tokyo (Japan). Life Science Institute; Kasai, Hisataka [Tokyo Metropolitan University of Health Sciences, Tokyo (Japan)

    1999-08-10

    As a trial to enhance activity of bioactive peptide, the dendrimeric formation of mastoparan (MP), a wasp venom toxic peptide, was carried out. We synthesized dendrimeric MPs consisting of 2,4 and 8 MP molecules formed on a branching lysine-core, and examined the hemolytic and catecholamine releasing activities and the circular dichroism. The activities of dendrimeric MPs were higher than that of MP and the {alpha}-helical contents increased with the increase of the number of branches in the dendrimers. The most potent dendrimer in hemolytic activity, approximately 8000 times as active as MP, was octameric MP which took 35 % {alpha}-helical content even in an aqueous buffer. Our results indicated that the dendrimeric formation of an amphipathic peptide should be a useful way to obtain highly active peptide as shown already in immunogenicity. (author)

  18. GLOBAL STAR FORMATION REVISITED

    A general treatment of disk star formation is developed from a dissipative multiphase model, with the dominant dissipation due to cloud collisions. The Schmidt-Kennicutt (SK) law emerges naturally for star-forming disks and starbursts. We predict that there should be an inverse correlation between Tully-Fisher law and SK law residuals. The model is extended to include a multiphase treatment of supernova feedback that leads to a turbulent pressure-regulated generalization of the star formation law and is applicable to gas-rich starbursts. Enhanced pressure, as expected in merger-induced star formation, enhances star formation efficiency. An upper limit is derived for the disk star formation rate in starbursts that depends on the ratio of global ISM to cloud pressures. We extend these considerations to the case where the interstellar gas pressure in the inner galaxy is dominated by outflows from a central active galactic nucleus (AGN). During massive spheroid formation, AGN-driven winds trigger star formation, resulting in enhanced supernova feedback and outflows. The outflows are comparable to the AGN-boosted star formation rate and saturate in the super-Eddington limit. Downsizing of both SMBH and spheroids is a consequence of AGN-driven positive feedback. Bondi accretion feeds the central black hole with a specific accretion rate that is proportional to the black hole mass. AGN-enhanced star formation is mediated by turbulent pressure and relates spheroid star formation rate to black hole accretion rate. The relation between black hole mass and spheroid velocity dispersion has a coefficient (Salpeter time to gas consumption time ratio) that provides an arrow of time. Highly efficient, AGN-boosted star formation can occur at high redshift.

  19. Reduction of Inflammatory Responses and Enhancement of Extracellular Matrix Formation by Vanillin-Incorporated Poly(Lactic-co-Glycolic Acid) Scaffolds

    Lee, Yujung; Kwon, JeongIl; Khang, Gilson; Lee, Dongwon

    2012-01-01

    Vanillin is one of the major components of vanilla, a commonly used flavoring agent and preservative and is known to exert potent antioxidant and anti-inflammatory activities. In this work, vanillin-incorporated poly(lactic-co-glycolic acid) (PLGA) films and scaffolds were fabricated to evaluate the effects of vanillin on the inflammatory responses and extracellular matrix (ECM) formation in vitro and in vivo. The incorporation of vanillin to PLGA films induced hydrophilic nature, resulting i...

  20. Formation of Anhydrite due to Interaction Between Water Soluble CO2 (aq) and Calcite Mineral During Enhanced Oil Recovery

    Chakravarty, Krishna Hara; Fosbøl, Philip Loldrup; Thomsen, Kaj

    2015-01-01

    In the Low Salinity based EOR method, formation and migration of fines have proved to have profound effect on the displacement efficiency of residual oil. Salinity variations of injected brines have also been shown to affect oil recovery for WAG-CO2 processes. But the effect of fines in EOR durin...... mineral dissolution and the observed increase in permeability. Copyright: 2015. Society of Petroleum Engineers...

  1. Osteopontin deficiency enhances parathyroid hormone/ parathyroid hormone related peptide receptor (PPR) signaling-induced alteration in tooth formation and odontoblastic morphology

    Morishita, Maki; Ono, Noriaki; Miyai, Kentano; Nakagawa, Tomomi; Hanyu, Ryo; Nagao, Masashi; Kamolratanakul, Paksinee; Notomi, Takuya; Rittling, Susan R; Denhardt, David T.; Kronenberg, Henry M.; Ezura, Yoichi; Hayata, Tadayoshi; Nakamoto, Tetsuya; Noda, Masaki

    2011-01-01

    Parathyroid hormone/parathyroid hormone-related protein receptor (PPR) signaling is known to be involved in tooth development. In bone, extracellular matrix protein osteopontin (OPN) is a negative regulator of PPR signaling in bone formation. However, the role of OPN in modulation of PPR action in tooth development is not understood. Therefore, we examined the tooth in double mutant mice. Constitutively active PPR was expressed specifically in the odontoblasts and osteoblasts (caPPR-tg) in th...

  2. ZFOURGE catalogue of AGN candidates: an enhancement of 160{\\mu}m-derived star-formation rates in active galaxies to $z$ = 3.2

    Cowley, Michael J; Tran, Kim-Vy H; Rees, Glen A; Labbé, Ivo; Allen, Rebecca J; Brammer, Gabriel B; Glazebrook, Karl; Hopkins, Andrew M; Juneau, Stéphanie; Kacprzak, Glenn G; Mullaney, James R; Nanayakkara, Themiya; Papovich, Casey; Quadri, Ryan F; Straatman, Caroline M S; Tomczak, Adam R; van Dokkum, Pieter G

    2016-01-01

    We investigate active galactic nuclei (AGN) candidates within the FourStar Galaxy Evolution Survey (ZFOURGE) to determine the impact they have on star-formation in their host galaxies. We first identify a population of radio, X-ray, and infrared-selected AGN by cross-matching the deep $K_{s}$-band imaging of ZFOURGE with overlapping multi-wavelength data. From this, we construct a mass-complete (log(M$_{*}$/M$_{\\odot}$) $\\ge$ 9.75), AGN luminosity limited sample of 235 AGN hosts over z = 0.2 - 3.2. We compare the rest-frame U - V versus V - J (UVJ) colours and specific star-formation rates (sSFRs) of the AGN hosts to a mass-matched control sample of inactive (non-AGN) galaxies. UVJ diagnostics reveal AGN tend to be hosted in a lower fraction of quiescent galaxies and a higher fraction of dusty galaxies than the control sample. Using 160{\\mu}m Herschel PACS data, we find the mean specific star-formation rate of AGN hosts to be elevated by 0.34$\\pm$0.07 dex with respect to the control sample across all redshift...

  3. Resonance enhanced multiphoton ionization time-of-flight (REMPI-TOF) study of phosphorous oxychloride (POCl3) dissociation at 235 nm: Dynamics of Cl(2Pj) formation

    Highlights: ► First results on dynamics of Cl atom formation in the photodissociation of POCl3. ► Two types of Cl atom formation mechanism. ► Cl2 formation from the ground state supported by ab initio calculation. -- Abstract: In one-color REMPI-TOF experiment, the photodissociation dynamics of POCl3 has been studied by photolyzing POCl3 and probing the chlorine atom photofragments, namely, Cl(2P3/2) and Cl∗(2P1/2) using 2 + 1 REMPI scheme, in the 234–236 nm region. We have determined the centre-of-mass photofragment speed distribution, recoil anisotropy parameter, and the spin–orbit branching ratio for chlorine atom elimination channels. The anisotropy parameters for Cl and Cl∗ are the same, and characterized by a value of 0.0 ± 0.05. Two components, namely, the fast and the slow, are observed in the translational energy distributions of Cl and Cl∗. The average translational energies for the Cl and Cl∗ channels for the fast components are 12.5 ± 1.5 and 16.8 ± 1.5 kcal/mol, while, for the slow components, the average translational energies are 1.5 ± 1.0 and 2.5 ± 1.0 kcal/mol, respectively. Apart from the chlorine atom elimination channel, Cl2 elimination is also observed in the photodissociation of POCl3.

  4. Formation and Characterization of Pd, Pt and Pd-Pt Alloy Films on Polyimide by Catalyst-Enhanced Chemical Vapor Deposition

    ZHOU Jinlan; CHENG Yinhua; Yousuf Hamadan; YU Kaichao

    2007-01-01

    Platinum, palladium and their alloy films on polyimide were formed by catalyst-enhanced chemical vapor deposition (CVD) in the carrier gas (N2, O2) at 220-300 ℃ under reduced pressure and normal pressure. The deposition of palladium complexes [ Pd((η3-allyl)(hfac) and Pd(hfac)2 ] gives pure palladium film,while the deposition of platinum needs the enhancement of palladium complex by mixing precursor platinum complex Pt(COD)Me2 and palladium complex in the same chamber. The co-deposition of Pd and Pt metals was used for the deposition of alloy films. During the CVD of palladium-platinum alloy, the Pd/Pt atomic ratios vary under different co-deposition conditions. These metal films were characterized by XPS and SEM, and show a good adhesive property.

  5. FORMATION OF SiC GRAINS IN PULSATION-ENHANCED DUST-DRIVEN WIND AROUND CARBON-RICH ASYMPTOTIC GIANT BRANCH STARS

    We investigate the formation of silicon carbide (SiC) grains in the framework of dust-driven wind around pulsating carbon-rich asymptotic giant branch (C-rich AGB) stars to reveal not only the amount but also the size distribution. Two cases are considered for the nucleation process: one is the local thermal equilibrium (LTE) case where the vibration temperature of SiC clusters Tv is equal to the gas temperature as usual, and another is the non-LTE case in which Tv is assumed to be the same as the temperature of small SiC grains. The results of the hydrodynamical calculations for a model with stellar parameters of mass M* = 1.0 M☉, luminosity L* = 104 L☉, effective temperature Teff = 2600 K, C/O ratio = 1.4, and pulsation period P = 650 days show the following: in the LTE case, SiC grains condense in accelerated outflowing gas after the formation of carbon grains, and the resulting averaged mass ratio of SiC to carbon grains of ∼10–8 is too small to reproduce the value of 0.01-0.3, which is inferred from the radiative transfer models. On the other hand, in the non-LTE case, the formation region of the SiC grains is more internal and/or almost identical to that of the carbon grains due to the so-called inverse greenhouse effect. The mass ratio of SiC to carbon grains averaged at the outer boundary ranges from 0.098 to 0.23 for the sticking probability αs = 0.1-1.0. The size distributions with the peak at ∼0.2-0.3 μm in radius cover the range of size derived from the analysis of the presolar SiC grains. Thus, the difference between the temperatures of the small cluster and gas plays a crucial role in the formation process of SiC grains around C-rich AGB stars, and this aspect should be explored for the formation process of dust grains in astrophysical environments.

  6. Stages in axon formation: observations of growth of Aplysia axons in culture using video-enhanced contrast-differential interference contrast microscopy

    1986-01-01

    The regenerative growth in culture of the axons of two giant identified neurons from the central nervous system of Aplysia californica was observed using video-enhanced contrast-differential interference contrast microscopy. This technique allowed the visualization in living cells of the membranous organelles of the growth cone. Elongation of axonal branches always occurred through the same sequence of events: A flat organelle-free veil protruded from the front of the growth cone, gradually f...

  7. Insulin-like Growth Factor-I and Slow, Bi-directional Perfusion Enhance the Formation of Tissue-Engineered Cardiac Grafts

    Cheng, Mingyu; Moretti, Matteo; Engelmayr, George C.; Freed, Lisa E.

    2008-01-01

    Biochemical and mechanical signals enabling cardiac regeneration can be elucidated using in vitro tissue-engineering models. We hypothesized that insulin-like growth factor-I (IGF) and slow, bi-directional perfusion could act independently and interactively to enhance the survival, differentiation, and contractile performance of tissue-engineered cardiac grafts. Heart cells were cultured on three-dimensional porous scaffolds in medium with or without supplemental IGF and in the presence or ab...

  8. Sulfate Formation Enhanced by a Cocktail of High NOx, SO2, Particulate Matter, and Droplet pH during Haze-Fog Events in Megacities in China: An Observation-Based Modeling Investigation.

    Xue, Jian; Yuan, Zibing; Griffith, Stephen M; Yu, Xin; Lau, Alexis K H; Yu, Jian Zhen

    2016-07-19

    In recent years in a few Chinese megacities, fog events lasting one to a few days have been frequently associated with high levels of aerosol loading characterized by high sulfate (as high as 30 μg m(-3)), therefore termed as haze-fog events. The concomitant pollution characteristics include high gas-phase mixing ratios of SO2 (up to 71 ppbv) and NO2 (up to 69 ppbv), high aqueous phase pH (5-6), and smaller fog droplets (as low as 2 μm), resulting from intense emissions from fossil fuel combustion and construction activities supplying abundant Ca(2+). In this work, we use an observation-based model for secondary inorganic aerosols (OBM-SIA) to simulate sulfate formation pathways under conditions of haze-fog events encountered in Chinese megacities. The OBM analysis has identified, at a typical haze-fogwater pH of 5.6, the most important pathway to be oxidation of S(IV) by dissolved NO2, followed by the heterogeneous reaction of SO2 on the aerosol surface. The aqueous phase oxidation of S(IV) by H2O2 is a very minor formation pathway as a result of the high NOx conditions suppressing H2O2 formation. The model results indicate that the unique cocktail of high fogwater pH, high concentrations of NO2, SO2, and PM, and small fog droplets are capable of greatly enhancing sulfate formation. Such haze-fog conditions could lead to rapid sulfate production at night and subsequently high PM2.5 in the morning when the fog evaporates. Sulfate formation is simulated to be highly sensitive to fogwater pH, PM, and precursor gases NO2 and SO2. Such insights on major contributing factors imply that reduction of road dust and NOx emissions could lessen PM2.5 loadings in Chinese megacities during fog events. PMID:27331615

  9. ZFOURGE catalogue of AGN candidates: an enhancement of 160-μm-derived star formation rates in active galaxies to z = 3.2

    Cowley, Michael J.; Spitler, Lee R.; Tran, Kim-Vy H.; Rees, Glen A.; Labbé, Ivo; Allen, Rebecca J.; Brammer, Gabriel B.; Glazebrook, Karl; Hopkins, Andrew M.; Juneau, Stéphanie; Kacprzak, Glenn G.; Mullaney, James R.; Nanayakkara, Themiya; Papovich, Casey; Quadri, Ryan F.; Straatman, Caroline M. S.; Tomczak, Adam R.; van Dokkum, Pieter G.

    2016-03-01

    We investigate active galactic nuclei (AGN) candidates within the FourStar Galaxy Evolution Survey (ZFOURGE) to determine the impact they have on star formation in their host galaxies. We first identify a population of radio, X-ray, and infrared-selected AGN by cross-matching the deep Ks-band imaging of ZFOURGE with overlapping multiwavelength data. From this, we construct a mass-complete (log(M_{{*}}/M_{{⊙}}) ≥9.75), AGN luminosity limited sample of 235 AGN hosts over z = 0.2-3.2. We compare the rest-frame U - V versus V - J (UVJ) colours and specific star formation rates (sSFRs) of the AGN hosts to a mass-matched control sample of inactive (non-AGN) galaxies. UVJ diagnostics reveal AGN tend to be hosted in a lower fraction of quiescent galaxies and a higher fraction of dusty galaxies than the control sample. Using 160 μm Herschel PACS data, we find the mean specific star formation rate of AGN hosts to be elevated by 0.34 ± 0.07 dex with respect to the control sample across all redshifts. This offset is primarily driven by infrared-selected AGN, where the mean sSFR is found to be elevated by as much as a factor of ˜5. The remaining population, comprised predominantly of X-ray AGN hosts, is found mostly consistent with inactive galaxies, exhibiting only a marginal elevation. We discuss scenarios that may explain these findings and postulate that AGN are less likely to be a dominant mechanism for moderating galaxy growth via quenching than has previously been suggested.

  10. Forward and reverse differential-pulse effects applied in the formation of a solid electrolyte interface to enhance the performance of lithium batteries

    Highlights: • A new solid electrolyte interface (SEI) was formed by the forward and reverse differential-pulse (FRDP) method. • This FRDP method facilitates the effective generation of the SEI by balancing the reaction kinetics of SEI formation. • The results obtained for the battery in which a suitable reverse pulse (RP)effect leads to outstanding battery performance regarding cycling ability at high temperatures (60 °C). - Abstract: In Li-ion batteries, the solid electrolyte interface (SEI) plays a crucial role in transferring Li ions into active materials through an electrochemical driving force. SEI is a composite layer containing of inorganic and organic components, which are fabricated by the salt degradation products and partial or complete reduction products of the solvent of the electrolyte at the battery's initial charge-discharge cycle. The chemical properties of SEI and the electrochemical driving force must be mutually optimized so as to strengthen its integrity, while minimizing irreversible SEI formation; thereby suppressing the decomposition at high temperatures. In this study, we investigated a new method of creating the SEI, i.e. the forward and reverse differential-pulse (FRDP) method, which balances the reaction kinetics of SEI formation. Furthermore, the use of the FRDP method also creates a SEI with a modified kinetic reaction route that affects battery performance. Here, we present data from the first charge-discharge and cycle performance at a high rate and a high temperature, obtained using scanning electron microscopy, electrochemical impedance spectroscopy, X-ray photoelectron spectroscopy, and Li+-diffusion kinetics analysis. Our findings indicate that the use of the FRDP method for generating the SEI results in a 58% reduction in the SEI's ionic diffusion activation energy and a 4.5% increase in battery capacity at room temperature, while increasing battery performance at 60 °C stability compared to batteries in which

  11. A Semantically Automated Protocol Adapter for Mapping SOAP Web Services to RESTful HTTP Format to Enable the Web Infrastructure, Enhance Web Service Interoperability and Ease Web Service Migration

    Frank Doheny

    2012-04-01

    Full Text Available Semantic Web Services (SWS are Web Service (WS descriptions augmented with semantic information. SWS enable intelligent reasoning and automation in areas such as service discovery, composition, mediation, ranking and invocation. This paper applies SWS to a previous protocol adapter which, operating within clearly defined constraints, maps SOAP Web Services to RESTful HTTP format. However, in the previous adapter, the configuration element is manual and the latency implications are locally based. This paper applies SWS technologies to automate the configuration element and the latency tests are conducted in a more realistic Internet based setting.

  12. CO2 laser irradiation enhances CaF2 formation and inhibits lesion progression on demineralized dental enamel-in vitro study.

    Zancopé, Bruna R; Rodrigues, Lívia P; Parisotto, Thais M; Steiner-Oliveira, Carolina; Rodrigues, Lidiany K A; Nobre-Dos-Santos, Marinês

    2016-04-01

    This study evaluated if Carbon dioxide (CO2) (λ 10.6 μm) laser irradiation combined with acidulated phosphate fluoride gel application (APF gel) enhances "CaF2" uptake by demineralized enamel specimens (DES) and inhibits enamel lesion progression. Thus, two studies were conducted and DES were subjected to APF gel combined or not with CO2 laser irradiation (11.3 or 20.0 J/cm(2), 0.4 or 0.7 W) performed before, during, or after APF gel application. In study 1, 165 DES were allocated to 11 groups. Fluoride as "CaF2 like material" formed on enamel was determined in 100 DES (n = 10/group), and the surface morphologies of 50 specimens were evaluated by scanning electron microscopy (SEM) before and after "CaF2" extraction. In study 2, 165 DES (11 groups, n = 15), subjected to the same treatments as in study 1, were further subjected to a pH-cycling model to simulate a high cariogenic challenge. The progression of demineralization in DES was evaluated by cross-sectional microhardness and polarized light microscopy analyses. Laser at 11.3 J/cm(2) applied during APF gel application increased "CaF2" uptake on enamel surface. Laser irradiation and APF gel alone arrested the lesion progression compared with the control (p fusion, and cracks were observed. CO2 laser irradiation, combined with a single APF application enhanced "CaF2" uptake on enamel surface and a synergistic effect was found. However, regarding the inhibition of caries lesion progression, no synergistic effect could be demonstrated. In conclusion, the results have shown that irradiation with specific laser parameters significantly enhanced CaF2 uptake by demineralized enamel and inhibited lesion progression. PMID:26873502

  13. Formation of SiC Grains in Pulsation-Enhanced Dust-Driven Wind Around Carbon Rich Asymptotic Giant Branch Stars

    Yasuda, Yuki

    2011-01-01

    We investigate the formation of silicon carbide (SiC) grains in the framework of dust-driven wind around pulsating carbon-rich Asymptotic Giant Branch (C-rich AGB) stars in order to reveal not only the amount but also the size distribution. Two cases are considered for the nucleation process; one is the LTE case where the vibration temperature of SiC clusters $T_{\\rm v}$ is equal to the gas temperature as usual, and another is the non-LTE case in which $T_{\\rm v}$ is assumed to be the same as the temperature of small SiC grains. The results of hydrodynamical calculations for a model with stellar parameters of mass $M_{\\ast}$=1.0 $M_{\\odot}$, luminosity $L_{\\ast}$=10$^{4}$ $L_{\\odot}$, effective temperature $T_{\\rm eff}$=2600 K, C/O ratio=1.4, and pulsation period $P$=650 days show the followings: In the LTE case, SiC grains condense in accelerated outflowing gas after the formation of carbon grains and the resulting averaged mass ratio of SiC to carbon grains of $\\sim$ 10$^{-8}$ is too small to reproduce the ...

  14. Giant enhancement of magnetocaloric effect at room temperature by the formation of nanoparticle of La0.48Ca0.52MnO3 compound

    Das, Kalipada; Das, I.

    2016-03-01

    Magnetocaloric effect (MCE) is the change in temperature or entropy of a material due to the application of external magnetic field. The temperature dependence of MCE shows maximum value near the ferromagnetic transition of the material. Material with large MCE near room temperature will make revolutionary change in cooling technology and will have large impact in human society. We have transformed antiferromagnetic bulk manganite material La0.48Ca0.52MnO3 to ferromagnetic material by the reduction of the particle size in nanometer scale. MCE, as well as the Relative cooling power (RCP) of the material at room temperature (RT) systematically increase with the reduction of the particle sizes. The RCP value for the 45 nm particle size sample at RT is about 400% larger compared with the bulk counterpart. Our detail study on the nano form of the compound highlights an effective way to enhance the MCE. It opens up a vast possibility of achieving giant enhancement of MCE of several already known materials just by the reduction of the particle size in nanometer scale.

  15. Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of CO2 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales

    The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a CO2 enhanced oil recovery project in the Antelope Shale in Buena Vista Hills Field. The Buena Vista Hills pilot CO2 project will demonstrate the economic viability and widespread applicability of CO2 flooding in fractured siliceous shale reservoirs of the San Joaquin Valley. The research consists of four primary work processes: (1) Reservoir Matrix and Fluid Characterization; (2) Fracture characterization; (3) reservoir Modeling and Simulation; and (4) CO2 Pilot Flood and Evaluation. Work done in these areas is subdivided into two phases or budget periods. The first phase of the project will focus on the application of a variety of advanced reservoir characterization techniques to determine the production characteristics of the Antelope Shale reservoir. Reservoir models based on the results of the characterization work will be used to evaluate how the reservoir will respond to secondary recovery and EOR processes. The second phase of the project will include the implementation and evaluation of an advanced enhanced oil recovery (EOR) pilot in the United Anticline (West Dome) of the Buena Vista Hills Field

  16. Insulin-like growth factor-I and slow, bi-directional perfusion enhance the formation of tissue-engineered cardiac grafts.

    Cheng, Mingyu; Moretti, Matteo; Engelmayr, George C; Freed, Lisa E

    2009-03-01

    Biochemical and mechanical signals enabling cardiac regeneration can be elucidated using in vitro tissue-engineering models. We hypothesized that insulin-like growth factor-I (IGF) and slow, bi-directional perfusion could act independently and interactively to enhance the survival, differentiation, and contractile performance of tissue-engineered cardiac grafts. Heart cells were cultured on three-dimensional porous scaffolds in medium with or without supplemental IGF and in the presence or absence of slow, bi-directional perfusion that enhanced transport and provided shear stress. Structural, molecular, and electrophysiologic properties of the resulting grafts were quantified on culture day 8. IGF had independent, beneficial effects on apoptosis (p < 0.01), cellular viability (p < 0.01), contractile amplitude (p < 0.01), and excitation threshold (p < 0.01). Perfusion independently affected the four aforementioned parameters and also increased amounts of cardiac troponin-I (p < 0.01), connexin-43 (p < 0.05), and total protein (p < 0.01) in the grafts. Interactive effects of IGF and perfusion on apoptosis were also present (p < 0.01). Myofibrillogenesis and spontaneous contractility were present only in grafts cultured with perfusion, although contractility was inducible by electrical field stimulation of grafts from all groups. Our findings demonstrate that multi-factorial stimulation of tissue-engineered cardiac grafts using IGF and perfusion resulted in independent and interactive effects on heart cell survival, differentiation, and contractility. PMID:18759675

  17. Enzyme-triggered formation of enzyme-tyramine concatamers on nanogold-functionalized dendrimer for impedimetric detection of Hg(II) with sensitivity enhancement.

    Qiu, Zhenli; Tang, Dianyong; Shu, Jian; Chen, Guonan; Tang, Dianping

    2016-01-15

    A new impedimetric sensing strategy based on enzyme-triggered formation of enzyme-tyramine concatamers on the nanogold-functionalized poly(amidoamine) (PAMAM) dendrimer was designed for sensitive detection of mercury(II) (Hg(2+)) ion, coupling with enzymatic biocatalytic precipitation towards 4-choloro-1-naphthol (4-CN) on thymine (T)-rich single-stranded DNA1-modified electrode. Initially, nanogold-decorated PAMAM dendrimer (AuNP-PAMAM) was synthesized by the in-situ reduction method, and then functionalized with horseradish peroxidase (HRP) and another T-rich oligomer (DNA2). Upon target Hg(2+) introduction, probe DNA2 on the AuNP-PAMAM bound to the DNA1 on the electrode owing to the T-Hg(2+)-T coordination chemistry between the two DNA strands. Accompanying the AuNP-PAMAM, the carried HRP could trigger the formation of HRP-tyramine concatamer via the classical tyramine signal amplification strategy in the presence of HRP-tyramine conjugates and hydrogen peroxide. The concatenated HRP molecules in the concatamer catalyzed the 4-CN oxidation to produce an insoluble precipitation on the electrode, thereby resulting in the local alteration in the conductivity. Under optimal conditions, two signal-generation tags including HRP-AuNP-DNA2 and HRP-AuNP-PAMAM-DNA2 with or without tyramine signal amplification strategy (i.e., four schemes) were used for impedimetric detection of target Hg(2+) on the basis of the same assay format. A low detection limit (LOD) of 0.4pM and a wide dynamic working range of 0.001-100nM Hg(2+) by using HRP-AuNP-PAMAM-DNA2 with tyramine signal amplification strategy were obtained in comparison with those of other strategies. The assay had a good repeatability and showed an intermediate precision of down to 9.6%. In addition, the methodology also exhibited high specificity and selectivity towards target Hg(2+) against other metal ions, and was applicable for monitoring Hg(2+) in the spiked drinking water samples. PMID:26301998

  18. Enhanced corrosion resistance of magnesium alloy by a silane-based solution treatment after an in-situ formation of the Mg(OH)2 layer

    Gong, Fubao; Shen, Jun; Gao, Runhua; Xie, Xiong; Luo, Xiong

    2016-03-01

    A novel organic-inorganic Mg(OH)2/silane surface layer has been developed for corrosion protection of AZ31 magnesium alloy. The results of electrochemical impedance spectroscopy (EIS), the immersion tests, Fourier-transform infrared spectroscopy (FTIR) and sellotape tests showed that the Mg(OH)2/silane-based composite surface layer possessed excellent corrosion resistance and very good adhesion due to the formation of Si-O-Mg bond between Mg(OH)2 layer and silane layer. Electrochemical impedance spectroscopy tests results indicated that for the long-term corrosion protection of AZ31 the increase of the curing temperature improved the impedance of the composited layer when the curing temperature was lower than 130 °С. However, the impedance of the composited layer deceased when the curing temperature was more than 130 °С due to the carbonization of the silane layer.

  19. Enhancing electrochemical water-splitting kinetics by polarization-driven formation of near-surface iron(0): an in situ XPS study on perovskite-type electrodes.

    Opitz, Alexander K; Nenning, Andreas; Rameshan, Christoph; Rameshan, Raffael; Blume, Raoul; Hävecker, Michael; Knop-Gericke, Axel; Rupprechter, Günther; Fleig, Jürgen; Klötzer, Bernhard

    2015-02-23

    In the search for optimized cathode materials for high-temperature electrolysis, mixed conducting oxides are highly promising candidates. This study deals with fundamentally novel insights into the relation between surface chemistry and electrocatalytic activity of lanthanum ferrite based electrolysis cathodes. For this means, near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) and impedance spectroscopy experiments were performed simultaneously on electrochemically polarized La0.6 Sr0.4 FeO3-δ (LSF) thin film electrodes. Under cathodic polarization the formation of Fe(0) on the LSF surface could be observed, which was accompanied by a strong improvement of the electrochemical water splitting activity of the electrodes. This correlation suggests a fundamentally different water splitting mechanism in presence of the metallic iron species and may open novel paths in the search for electrodes with increased water splitting activity. PMID:25557533

  20. Protein-containing nutrient supplementation following strength training enhances the effect on muscle mass, strength, and bone formation in postmenopausal women

    Holm, Lars; Olesen, Jens L; Matsumoto, Keitaro;

    2008-01-01

    We evaluated the response of various muscle and bone adaptation parameters with 24 wk of strength training in healthy, early postmenopausal women when a nutrient supplement (protein, carbohydrate, calcium, and vitamin D) or a placebo supplement (a minimum of energy) was ingested immediately...... following each training session. At inclusion, each woman was randomly and double-blindedly assigned to a nutrient group or a placebo (control) group. Muscle hypertrophy was evaluated from biopsies, MRI, and dual-energy X-ray absorptiometry (DEXA) scans, and muscle strength was determined in a dynamometer...... nutrient supplementation results in superior improvements in muscle mass, muscle strength, femoral neck BMD, and bone formation during 24 wk of strength training. The observed differences following such a short intervention emphasize the significance of postexercise nutrient supply on musculoskeletal...

  1. Genetic Engineering Modification of Microalgae to Enhance CO2 Fixation and Oil Formation%固碳产油微藻的基因工程改造

    于水燕; 赵权宇; 史吉平

    2012-01-01

    Fossil fuels are un-renewable and over-emission of CO2 brings on the global warming. Biodiesel from microalgae is considered as a potential alternative energy. CO2 could be fixed by microalgae via photosynthesis to synthesize the oil. Microalgal biodiesel is further produced by trans-esterification of triglycerides with methanol. There are several advantages of microalgae biodiesel compared with other biofuels. Microalgae as a next generation feedstock for biofuel production have obtained worldwide attention. The neutral lipids especially triacylglycerols (TAG) which are the main feedstock of oil can be accumulated in many microalgae cells under stress conditions. Three promising strategies are feasible to enhance TAG accumulation in microalgae: the biochemical engineering approach, the genetic engineering ( GE ) approach, and the transcription factor engineering approach. The genetic engineering modification has now become a new research hot point to enhance the lipid production in oil-rich microalgae. An overview of the advances of some genes in lipid biosynthesis pathway in microalgae, and the metabolic regulation strategies for enhancing lipid accumulation was presented. Correlated with the TAG accumulating, some genes in six metabolic pathways are summarized including carbon fixation, central carbon metabolism, fatty acid biosynthesis, TAG assembling, inhibition of competing pathways of TAG and the lipid degradation catabolism. Exploring these enzymes and their functions involved in the pathways are helpful for the genetic engineering modification of microalgae. Finally, the current genetic engineering methods and technical issues of microalgae, the feasibility of genetic engineering modification of microalgae and possibilities of microalgae as feedstock for biofuels and its integrated utilization are further discussed.%藻种的选育和基因工程改造是微藻生物柴油研究的核心.为此,简要综述了微藻从光合作用到甘油三酯(TAG)合

  2. Enhanced dentin-like mineralized tissue formation by AdShh-transfected human dental pulp cells and porous calcium phosphate cement.

    Lunguo Xia

    Full Text Available The aim of the present study was to investigate the effect of Sonic hedgehog (Shh on human dental pulp cells (hDPCs and the potential of complexes with Shh gene modified hDPCs and porous calcium phosphate cement (CPC for mineralized tissue formation. hDPCs were cultured and transfected with adenoviral mediated human Shh gene (AdShh. Overexpression of Shh and cell proliferation was tested by real-time PCR analysis, western blotting analysis, and MTT analysis, respectively. The odontoblastic differentiation was assessed by alkaline phosphatase (ALP activity and real-time PCR analysis on markers of Patched-1 (Ptc-1, Smoothened (Smo, Gli 1, Gli 2, Gli 3, osteocalcin (OCN, dentin matrix protein-1 (DMP-1, and dentin sialophosphoprotein (DSPP. Finally, AdShh-transfected hDPCs were combined with porous CPC and placed subcutaneously in nude mice for 8 and 12 weeks, while AdEGFP-transfected and untransfected hDPCs were treated as control groups. Results indicated that Shh could promote proliferation and odontoblastic differentiation of hDPCs, while Shh/Gli 1 signaling pathway played a key role in this process. Importantly, more mineralized tissue formation was observed in combination with AdShh transfected hDPCs and porous CPC, moreover, the mineralized tissue exhibited dentin-like features such as structures similar to dentin-pulp complex and the positive staining for DSPP protein similar to the tooth tissue. These results suggested that the constructs with AdShh-transfected hDPCs and porous CPC might be a better alternative for dental tissue regeneration.

  3. Enhancement of Osteoclastic Bone Resorption and Suppression of Osteoblastic Bone Formation in Response to Reduced Mechanical Stress Do Not Occur in the Absence of Osteopontin

    Ishijima, Muneaki; Rittling, Susan R.; Yamashita, Teruhito; Tsuji, Kunikazu; Kurosawa, Hisashi; Nifuji, Akira; Denhardt, David T.; Noda, Masaki

    2001-01-01

    Reduced mechanical stress to bone in bedridden patients and astronauts leads to bone loss and increase in fracture risk which is one of the major medical and health issues in modern aging society and space medicine. However, no molecule involved in the mechanisms underlying this phenomenon has been identified to date. Osteopontin (OPN) is one of the major noncollagenous proteins in bone matrix, but its function in mediating physical-force effects on bone in vivo has not been known. To investigate the possible requirement for OPN in the transduction of mechanical signaling in bone metabolism in vivo, we examined the effect of unloading on the bones of OPN−/− mice using a tail suspension model. In contrast to the tail suspension–induced bone loss in wild-type mice, OPN−/− mice did not lose bone. Elevation of urinary deoxypyridinoline levels due to unloading was observed in wild-type but not in OPN−/− mice. Analysis of the mechanisms of OPN deficiency–dependent reduction in bone on the cellular basis resulted in two unexpected findings. First, osteoclasts, which were increased by unloading in wild-type mice, were not increased by tail suspension in OPN−/− mice. Second, measures of osteoblastic bone formation, which were decreased in wild-type mice by unloading, were not altered in OPN−/− mice. These observations indicate that the presence of OPN is a prerequisite for the activation of osteoclastic bone resorption and for the reduction in osteoblastic bone formation in unloaded mice. Thus, OPN is a molecule required for the bone loss induced by mechanical stress that regulates the functions of osteoblasts and osteoclasts. PMID:11157060

  4. Enhancement on wettability and intermetallic compound formation with an addition of Al on Sn-0.7Cu lead-free solder fabricated via powder metallurgy method

    Adli, Nisrin; Razak, Nurul Razliana Abdul; Saud, Norainiza

    2016-07-01

    Due to the toxicity of lead (Pb), the exploration of another possibility for lead-free solder is necessary. Nowadays, SnCu alloys are being established as one of the lead-free solder alternatives. In this study, Sn-0.7Cu lead-free solder with an addition of 1wt% and 5wt% Al were investigated by using powder metallurgy method. The effect of Al addition on the wettability and intermetallic compound thickness (IMC) of Sn-0.7Cu-Al lead-free solder were appraised. Results showed that Al having a high potential to enhance Sn-0.7Cu lead-free solder due to its good wetting and reduction of IMC thickness. The contact angle and IMC of the Sn-0.7Cu-Al lead-free solder were decreased by 14.32% and 40% as the Al content increased from 1 wt% to 5 wt%.

  5. Formation and characterization of the MgO protecting layer deposited by plasma-enhanced metal-organic chemical-vapor deposition

    MgO films were prepared on Si(100) and soda-lime glass substrates by using plasma-enhanced metal-organic chemical-vapor deposition. Various ratios of the O2/CH3MgOtBu gas mixture and various gas flow rates were tested for the film fabrications. Highly (100)-oriented MgO films with good crystallinity were obtained with a 10 sccm CH3MgOtBu flow without an O2 gas flow. About 5 % carbon was contained in all the MgO films. The refractive index and the secondary electron emission coefficient for the best quality film were 1.43 and 0.45, respectively. The sputtering rate was about 0.2 nm/min for 1011 cm-3 Ar+ ion density. Annealing at 500 .deg. C in an Ar ambient promoted the grain size without inducing a phase transition

  6. Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of CO2 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales, Class III

    Perri, Pasquale R.; Cooney, John; Fong, Bill; Julander, Dale; Marasigan, Aleks; Morea, Mike; Piceno, Deborah; Stone, Bill; Emanuele, Mark; Sheffield, Jon; Wells, Jeff; Westbrook, Bill; Karnes, Karl; Pearson, Matt; Heisler, Stuart

    2000-04-24

    The primary objective of this project was to conduct advanced reservoir characterization and modeling studies in the Antelope Shale of the Bureau Vista Hills Field. Work was subdivided into two phases or budget periods. The first phase of the project focused on a variety of advanced reservoir characterization techniques to determine the production characteristics of the Antelope Shale reservoir. Reservoir models based on the results of the characterization work would then be used to evaluate how the reservoir would respond to enhanced oil recovery (EOR) processes such as of CO2 flooding. The second phase of the project would be to implement and evaluate a CO2 in the Buena Vista Hills Field. A successful project would demonstrate the economic viability and widespread applicability of CO2 flooding in siliceous shale reservoirs of the San Joaquin Valley.

  7. Enhanced bone formation in electrospun poly(l-lactic-co-glycolic acid)-tussah silk fibroin ultrafine nanofiber scaffolds incorporated with graphene oxide.

    Shao, Weili; He, Jianxin; Sang, Feng; Wang, Qian; Chen, Li; Cui, Shizhong; Ding, Bin

    2016-05-01

    To engineer bone tissue, it is necessary to provide a biocompatible, mechanically robust scaffold. In this study, we fabricated an ultrafine nanofiber scaffold by electrospinning a blend of poly(l-lactic-co-glycolic acid), tussah silk fibroin, and graphene oxide (GO) and characterized its morphology, biocompatibility, mechanical properties, and biological activity. The data indicate that incorporation of 10wt.% tussah silk and 1wt.% graphene oxide into poly(l-lactic-co-glycolic acid) nanofibers significantly decreased the fiber diameter from 280 to 130nm. Furthermore, tussah silk and graphene oxide boosted the Young's modulus and tensile strength by nearly 4-fold and 3-fold, respectively, and significantly enhanced adhesion, proliferation in mouse mesenchymal stem cells and functionally promoted biomineralization-relevant alkaline phosphatase (ALP) and mineral deposition. The results indicate that composite nanofibers could be excellent and versatile scaffolds for bone tissue engineering. PMID:26952489

  8. Lactobacillus plantarum MB452 enhances the function of the intestinal barrier by increasing the expression levels of genes involved in tight junction formation

    McCann Mark J

    2010-12-01

    Full Text Available Abstract Background Intestinal barrier function is important for preserving health, as a compromised barrier allows antigen entry and can induce inflammatory diseases. Probiotic bacteria can play a role in enhancing intestinal barrier function; however, the mechanisms are not fully understood. Existing studies have focused on the ability of probiotics to prevent alterations to tight junctions in disease models, and have been restricted to a few tight junction bridging proteins. No studies have previously investigated the effect of probiotic bacteria on healthy intestinal epithelial cell genes involved in the whole tight junction signalling pathway, including those encoding for bridging, plaque and dual location tight junction proteins. Alteration of tight junction signalling in healthy humans is a potential mechanism that could lead to the strengthening of the intestinal barrier, resulting in limiting the ability of antigens to enter the body and potentially triggering undesirable immune responses. Results The effect of Lactobacillus plantarum MB452 on tight junction integrity was determined by measuring trans-epithelial electrical resistance (TEER across Caco-2 cell layers. L. plantarum MB452 caused a dose-dependent TEER increase across Caco-2 cell monolayers compared to control medium. Gene expression was compared in Caco-2 cells untreated or treated with L. plantarum MB452 for 10 hours. Caco-2 cell RNA was hybridised to human oligonucleotide arrays. Data was analysed using linear models and differently expressed genes were examined using pathway analysis tools. Nineteen tight junction-related genes had altered expression levels in response to L. plantarum MB452 (modified-P 1.2, including those encoding occludin and its associated plaque proteins that anchor it to the cytoskeleton. L. plantarum MB452 also caused changes in tubulin and proteasome gene expression levels which may be linked to intestinal barrier function. Caco-2 tight junctions

  9. Enhanced uptake and translocation of arsenic in Cretan brake fern (Pteris cretica L.) through siderophorearsenic complex formation with an aid of rhizospheric bacterial activity.

    Jeong, Seulki; Moon, Hee Sun; Nam, Kyoungphile

    2014-09-15

    Siderophores, produced by Pseudomonas aeruginosa, released slightly more Fe (53.6 μmol) than that chelated by ethylenediaminetetraacetic acid (EDTA; i.e. 43.7 μmol) in batch experiment using As-adsorbed ferrihydrite. More importantly, about 1.79 μmol of As was found to be associated with siderophores in the aqueous phase due to siderophore-As complex formation when siderophores were used to release As from ferrihydrite. In contrast, As was not detected in the aqueous phase when EDTA was used, probably due to the readsorption of released As to ferrihydrite. A series of pot experiment was conducted to investigate the effect of siderophores as a microbial iron-chelator on As uptake by Cretan brake fern (Pteris cretica L.) during phtoextraction. Results revealed that P. cretica, a known As hyperaccumulator, grown in the siderophore-amended soil showed about 3.7 times higher As uptake (5.62 mg-Asg(-1)-plant) than the plant grown in the EDTA-treated soil (1.51 mg-Asg(-1)-plant). In addition, As taken up by roots of P. cretica in the presence of siderophores seemed to be favorably translocated to shoots (i.e. stems and leaves). About 79% of the accumulated As was detected in the shoots in the presence of siderophores after ten weeks. Fluorescence microscopic analysis confirmed that As in the roots was delivered to the leaves of P. cretica as a siderophore-As complex. PMID:25215655

  10. Line formation in winds with enhanced equatorial mass-loss rates and its application to the Wolf-Rayet star HD 50896

    Ultraviolet spectra from the ''Copernicus'' satellite of the Wolf-Rayet star HD 50896 show several P-Cygni profiles whose emission component has a larger equivalent width than the absorption component. For lines with saturated absorption components, such as the N V (lambdalambda1239-1243) line, the excess emission is due to thermal emission from the wind. However, for unsaturated lines which are due to scattering, such as the P V (lambdalambda1118-1128) and O VI (lambdalambda1032-1038) lines, the excess emission suggests that the scattering is not spherically symmetric. Based on this premise, a simple model was developed of a stellar wind whose material is concentrated toward the star's equatorial plane. This model was used to investigate the effect on line formation of the distribution of material in the wind and the orientation of the star-wind system with respect to an observer. In addition, the influence of the wind's velocity structure was investigated for two velocity laws which are schematically depicted. The first distribution has the asymptotic behavior expected for a radiatively accelerated wind. The second one has a similar form in the outer region of the wind, but has a velocity plateau at the inner region, as suggested by ultraviolet to infrared continuum fits of Hartmann and Cassinelli (1977). To simplify calculations, the Sobolev escape probability method was used, and the velocity structure was assumed to be spherically symmetric. (Auth.)

  11. The inhibition of Pseudomonas aeruginosa biofilm formation by micafungin and the enhancement of antimicrobial agent effectiveness in BALB/c mice.

    Kissoyan, Kohar Annie B; Bazzi, Wael; Hadi, Usamah; Matar, Ghassan M

    2016-08-01

    Micafungin inhibits biofilm formation by impeding 1,3-β-D-glucan synthesis in Candida albicans. Since Pseudomonas aeruginosa also has 1,3-β-D-glucan in its cell wall, this study assessed the effects of antibacterial agents in vitro and in vivo on micafungin-treated biofilm-forming P. aeruginosa isolates. After treatment with micafungin as well as with a panel of four antibacterial agents, biofilm production was significantly reduced as measured by spectrophotometry. The relative mRNA transcription levels for the genes encoding pellicles (pelC) and cell wall 1,3-β-D-glucan (ndvB), which were measured by quantitative reverse transcription PCR (qRT-PCR), significantly decreased with micafungin treatment. In vivo, the survival rates of P. aeruginosa-infected BALB/c mice significantly increased after combined treatment with micafungin and each of the antibacterial agents. Of these treatments, the combination of micafungin with levofloxacin had the highest survival rate; this combination was the most effective treatment against P. aeruginosa-induced infection. PMID:27347641

  12. Enhanced micronucleus formation in the descendants of γ-ray-irradiated tobacco cells: Evidence for radiation-induced genomic instability in plant cells

    Ionizing radiation-induced genomic instability has been documented in various end points such as chromosomal aberrations and mutations, which arises in the descendants of irradiated mammalian or yeast cells many generations after the initial insult. This study aimed at addressing radiation-induced genomic instability in higher plant tobacco cells. We thus investigated micronucleus (MN) formation and cell proliferation in tobacco cells irradiated with γ-rays and their descendants. In γ-irradiated cells, cell cycle was arrested at G2/M phase at around 24 h post-irradiation but released afterward. In contrast, MN frequency peaked at 48 h post-irradiation. Almost half of 40 Gy-irradiated cells had MN at 48 h post-irradiation, but proliferated as actively as sham-irradiated cells up to 120 h post-irradiation. Moreover, the descendants that have undergone at least 22 generations after irradiation still showed a two-fold MN frequency compared to sham-irradiated cells. This is the direct evidence for radiation-induced genomic instability in tobacco cells.

  13. Time series analysis supporting the hypothesis that enhanced cosmic radiation during germ cell formation can increase breast cancer mortality in germ cell cohorts

    Juckett, D. A.; Rosenberg, Barnett

    Techniques from cancer epidemiology and time series analysis were used to explore the hypothesis that cosmic radiation can induce germ cell changes leading to increases in future breast cancer mortality. A birth cohort time series for female breast cancer mortality was obtained using a model-independent, age-period-cohort analysis on age-specific mortality data for 1940-1990. The birth cohort series contained several oscillatory components, which were isolated and compared to the corresponding frequency components of a cosmic ray surrogate time series - Greenland ice-core 10Be concentrations. A technique, referred to as component wave-train alignment, was used to show that the breast cancer and cosmic ray oscillations were phase-locked approx. 25 years before the time of birth. This is consistent with the time of germ cell formation, which occurs during the fetal development stage of the preceding generation. Evidence is presented that the observable oscillations in the birth cohort series were residues of oscillations of much larger amplitude in the germ cell cohort, which were attenuated by the effect of the broad maternal age distribution. It is predicted that a minimum of 50% of breast cancer risk is associated with germ cell damage by cosmic radiation (priming event), which leads to the development of individuals with a higher risk of breast cancer. It is proposed that the priming event, by preceding other steps of carcinogenesis, works in concert with risk factor exposure during life. The priming event is consistent with epigenetic changes such as imprinting.

  14. Listeria monocytogenes survival of UV-C radiation is enhanced by presence of sodium chloride, organic food material and by bacterial biofilm formation

    Bernbom, Nete; Vogel, Birte Fonnesbech; Gram, Lone

    2011-01-01

    biofilm for 7days before exposure. It is not known if this enhanced survival is due to physiological changes in the attached bacterial cells, a physical protection of the cells in the food matrix or a combination. In conclusion, we demonstrate that UV-C light is a useful extra bacteriocidal step and that......The bactericidal effect on food processing surfaces of ceiling-mounted UV-C light (wavelength 254nm) was determined in a fish smoke house after the routine cleaning and disinfection procedure. The total aerobic counts were reduced during UV-C light exposure (48h) and the number of Listeria...... numbers declined with 4–5log units during exposure of 8–10min. Bacteria grown in juice prepared from cold-smoked salmon were protected and numbers were reduced with 2–3log when UV-C light was used immediately after attachment whereas numbers did not change at all if bacteria had been allowed to form a...

  15. Formation and characterization of the MgO protecting layer deposited by plasma-enhanced metal-organic chemical-vapor deposition

    Kang, M S; Byun, J C; Kim, D S; Choi, C K; Lee, J Y; Kim, K H

    1999-01-01

    MgO films were prepared on Si(100) and soda-lime glass substrates by using plasma-enhanced metal-organic chemical-vapor deposition. Various ratios of the O sub 2 /CH sub 3 MgO sup t Bu gas mixture and various gas flow rates were tested for the film fabrications. Highly (100)-oriented MgO films with good crystallinity were obtained with a 10 sccm CH sub 3 MgO sup t Bu flow without an O sub 2 gas flow. About 5 % carbon was contained in all the MgO films. The refractive index and the secondary electron emission coefficient for the best quality film were 1.43 and 0.45, respectively. The sputtering rate was about 0.2 nm/min for 10 sup 1 sup 1 cm sup - sup 3 Ar sup + ion density. Annealing at 500 .deg. C in an Ar ambient promoted the grain size without inducing a phase transition.

  16. Characterization of HfOxNy thin film formation by in-situ plasma enhanced atomic layer deposition using NH3 and N2 plasmas

    Highlights: • Analysis of PE-ALD grown HfON thin films using NH3 and N2 plasmas. • PE-ALD grown HfON film showed high dielectric constant and thermal stability. • PE-ALD grown HfON film suppressed the interfacial layer. • High leakage current of HfON film was caused by bandgap lowing and band offset. - Abstract: The structural and electrical characteristics of in-situ nitrogen-incorporated plasma enhanced atomic layer deposition (PE-ALD) HfOxNy thin films using NH3 and N2 plasmas as reactants were comparatively studied. The HfOxNy test structures prepared using NH3 and N2 plasmas were analyzed by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and high resolution transmission electron microscopy (HR-TEM) to investigate the chemical composition, crystallinity, and cross-sectional layers including the interfacial layer, respectively. By utilizing NH3 and N2 plasmas, the nitrogen-incorporated HfOxNy thin films fabricated by in-situ PE-ALD showed a high dielectric constant and thermal stability, which suppresses the interfacial layer and increases the crystallization temperature. The high leakage current densities of the HfOxNy thin film test structures fabricated using NH3 and N2 plasmas caused by lowering the energy bandgap and band offset are related to the Hf−N bond ratio and dielectric constant

  17. Enhanced magnetoelectric properties of BiFeO3 on formation of BiFeO3/SrFe12O19 nanocomposites

    Das, Anusree; Chatterjee, Souvik; Bandyopadhyay, Sudipta; Das, Dipankar

    2016-06-01

    Nanocomposites (NCs) comprising (1-x) BiFeO3 (BFO) and x SrFe12O19 (SRF) (x = 0.1, 0.2, 0.3, and 0.4) have been prepared by a sol-gel route. Presence of pure phases of both BiFeO3 (BFO) and SrFe12O19 (SRF) in the NCs for x = 0.3 and 0.4 has been confirmed by Rietveld analysis of XRD data though a minor impurity phase is observed in the case of x = 0.1 and 0.2 NCs. Transmission electron micrographs of the NCs show that particles are mostly spherical with average size of 30 nm. M-H measurements at 300 and 10 K indicate predominantly ferrimagnetic behavior of all the NCs with an increasing trend of saturation magnetization values with increasing content of SRF. Dielectric constant (ɛr) of the NCs at room temperature shows a dispersive behavior with frequency and attains a constant value at higher frequency. ɛr - T measurements reveal an increasing trend of dielectric constant of the NCs with increasing temperature and show an anomaly around the antiferromagnetic transition temperature of BFO, which indicates magnetoelectric coupling in the NCs. The variation of capacitance in the presence of magnetic field confirms the enhancement of magnetoelectric effect in the NCs. 57Fe Mössbauer spectroscopy results indicate the presence of only Fe3+ ions in usual crystallographic sites of BFO and SRF.

  18. Enhancement of the visible light activity and stability of Ag2CO3 by formation of AgI/Ag2CO3 heterojunction

    Yu, Changlin; Wei, Longfu; Zhou, Wanqin; Chen, Jianchai; Fan, Qizhe; Liu, Hong

    2014-11-01

    An insurmountable problem for silver-based semiconductor photocatalysts is their poor stability. Here, at room temperature, AgI with different concentrations (5%, 10%, 20% and 30%) were coupled into Ag2CO3, producing a series of novel AgI/Ag2CO3 composite photocatalysts. The effects of AgI addition on the Ag2CO3 catalyst for photocatalytic degradation of methyl orange (MO) under visible light irradiation have been investigated. Some physicochemical technologies like N2 physical adsorption/desorption, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray photoelectron spectroscopy (XPS), and UV-vis diffuse reflectance spectroscopy (UV-vis DRS) were applied to characterize these products. Results show that the photocatalytic degradation activity of AgI/Ag2CO3 photocatalyst is much higher than that of pure AgI and Ag2CO3. With the optimal content of AgI (20 wt%), the AgI/Ag2CO3 exhibits the highest photocatalytic degradation efficiency. Its first order reaction rate constant (0.54 h-1) is 20 times of that of AgI (0.026 h-1) and 3.6 times of that of Ag2CO3 (0.15 h-1). The characterizations and theory calculation show that AgI and Ag2CO3 have suitably matched band gap structures. The formation of AgI/Ag2CO3 heterojunction with intimate interface could effectively increase the separation efficiency of the e-/h+ pairs and promote the production of •OH and O2•- radicals, which brings about the fast degradation rate of the dye and an increase in photocatalytic stability.

  19. Granulocyte macrophage colony-stimulating factor enhances the modulatory effect of cytokines on monocyte-derived multinucleated giant cell formation and fungicidal activity against Paracoccidioides brasiliensis

    Magda Paula Pereira do Nascimento

    2011-09-01

    Full Text Available Multinucleated giant cells (MGC are cells present in characteristic granulomatous inflammation induced by intracellular infectious agents or foreign materials. The present study evaluated the modulatory effect of granulocyte macrophage colony-stimulating factor (GM-CSF in association with other cytokines such as interferon-gamma (IFN-γ, tumour necrosis factor-alpha, interleukin (IL-10 or transforming growth factor beta (TGF-β1 on the formation of MGC from human peripheral blood monocytes stimulated with Paracoccidioides brasiliensis antigen (PbAg. The generation of MGC was determined by fusion index (FI and the fungicidal activity of these cells was evaluated after 4 h of MGC co-cultured with viable yeast cells of P. brasiliensis strain 18 (Pb18. The results showed that monocytes incubated with PbAg and GM-CSF plus IFN-γ had a significantly higher FI than in all the other cultures, while the addition of IL-10 or TGF-β1 had a suppressive effect on MGC generation. Monocytes incubated with both pro and anti-inflammatory cytokines had a higher induction of foreign body-type MGC rather than Langhans-type MGC. MGC stimulated with PbAg and GM-CSF in association with the other cytokines had increased fungicidal activity and the presence of GM-CSF also partially inhibited the suppressive effects of IL-10 and TGF-β1. Together, these results suggest that GM-CSF is a positive modulator of PbAg-stimulated MGC generation and on the fungicidal activity against Pb18.

  20. 微乳形成机理及其药物增溶作用的研究进展%Research Progress in Formation Mechanism of Microemulsion and Its Applications in Drug Solubility Enhancement

    谢静; 张迎庆; 皮建斌; 糜志远

    2011-01-01

    The microemulsion systems are widely used for their thermodynamic stability, low viscosity, translucent appearance and low price. In this paper,theories about formation mechanism of microemulsions were introduced,the application proceeding of solubility enhancement for insoluble drugs by the microemulsions in injection,orally and transdermal administration system were reviewed,and the current problems and prospects of microemulsion drug delivery system were analyzed.%概述了微乳形成机理的主要学说,对微乳增溶难溶药物在注射、口服和经皮给药中的应用进展进行了综述,并对目前存在的问题和发展进行了分析.

  1. In situ formation of a ZnO/ZnSe nanonail array as a photoelectrode for enhanced photoelectrochemical water oxidation performance

    Wang, Liyang; Tian, Guohui; Chen, Yajie; Xiao, Yuting; Fu, Honggang

    2016-04-01

    In this study, a ZnO/ZnSe nanonail array was prepared via a two-step sequential hydrothermal synthetic route. In this synthetic process, the ZnO nanorod array was first grown on a fluorine-doped tin oxide (FTO) substrate using a seed-mediated growth approach via the hydrothermal process. Then, the ZnO nanonail array was obtained via in situ growth of ZnSe nano caps onto the ZnO nanorod array via a hydrothermal process in the presence of a Se source. The surface morphology and amount of ZnSe grown on the surface of the ZnO nanorods can be regulated by varying the reaction time and reactant concentration. Compared with pure ZnO nanorods, this unique nanonail array heterostructure exhibits enhanced visible light absorption. The transient photocurrent condition, in combination with steady-state and time-resolved photoluminescence spectroscopy, reveals that the ZnO/ZnSe nanonail array electrode has the highest charge separation rate, highest electron injection efficiency, and highest chemical stability. The photocurrent density of the ZnO/ZnSe nanonail array heterostructure reaches 1.01 mA cm-2 at an applied potential of 0.1 V (vs. Ag/AgCl), which is much higher than that of the ZnO/ZnSe nanorod array (0.71 mA cm-2), the pristine ZnO nanorod array (0.39 mA cm-2), and the ZnSe electrode (0.21 mA cm-2), indicating its significant visible light driven activities for photoelectrochemical water oxidation. This unique morphology of nail-capped nanorods might be important for providing better insight into the correlation between heterostructure and photoelectrochemical activity.In this study, a ZnO/ZnSe nanonail array was prepared via a two-step sequential hydrothermal synthetic route. In this synthetic process, the ZnO nanorod array was first grown on a fluorine-doped tin oxide (FTO) substrate using a seed-mediated growth approach via the hydrothermal process. Then, the ZnO nanonail array was obtained via in situ growth of ZnSe nano caps onto the ZnO nanorod array via a

  2. Formation of ZnO-Cd(OH){sub 2} core-shell nanoparticles by sol-gel method: An approach to modify surface chemistry for stable and enhanced green emission

    Mishra, Rupali, E-mail: rupalimishra@rediffmail.co [Department of Physics, University of Allahabad, Allahabad-211002 (India); Nanophosphor Application Centre, University of Allahabad, Allahabad-211002 (India); Yadav, Raghvendra S.; Pandey, Avinash C. [Department of Physics, University of Allahabad, Allahabad-211002 (India); Nanophosphor Application Centre, University of Allahabad, Allahabad-211002 (India); Sanjay, Sharda. S. [Department of Chemistry, Ewing Christian College, Allahabad (India); Dar, Chitra [Department of Physics, University of Allahabad, Allahabad-211002 (India)

    2010-03-15

    We report the formation of highly stable and luminescent ZnO-Cd(OH){sub 2} core-shell nanoparticles by simple introduction of cadmium salt in the initial precursor solution, used to synthesize ZnO nanoparticles by sol-gel route. The cadmium to zinc salt concentration ratio has been also varied to control the growth of ZnO nanoparticles at the smaller particle size. Formation of ZnO-Cd(OH){sub 2} core-shell nanostructure has been confirmed by X-ray diffraction (XRD), energy dispersive analysis of X-rays (EDAX) and X-ray photoelectron spectroscopy (XPS). UV-vis absorption spectroscopy exhibits blue-shift in absorption edge on increasing cadmium concentrations. The photoluminescence emission spectra showed the remarkably stable and enhanced visible (green) emission from suspended ZnO-Cd(OH){sub 2} nanoparticles in comparison to bare ZnO nanoparticles. It is postulated that Cd(OH){sub 2} layer at the surface of ZnO nanoparticles prevents the agglomeration of nanoparticles and efficiently assists the trapping of hole at the surface site, a first step necessary for visible emission. The Fourier transform infrared spectroscopy (FTIR) also supports our assumption about surface chemistry.

  3. Stellar formation

    Reddish, V C

    1978-01-01

    Stellar Formation brings together knowledge about the formation of stars. In seeking to determine the conditions necessary for star formation, this book examines questions such as how, where, and why stars form, and at what rate and with what properties. This text also considers whether the formation of a star is an accident or an integral part of the physical properties of matter. This book consists of 13 chapters divided into two sections and begins with an overview of theories that explain star formation as well as the state of knowledge of star formation in comparison to stellar structure

  4. Galaxy formation

    Galaxy formation is at the forefront of observation and theory in cosmology. An improved understanding is essential for improving our knowledge both of the cosmological parameters, of the contents of the universe, and of our origins. In these lectures intended for graduate students, galaxy formation theory is reviewed and confronted with recent observational issues. In lecture 1, the following topics are presented: star formation considerations, including IMF, star formation efficiency and star formation rate, the origin of the galaxy luminosity function, and feedback in dwarf galaxies. In lecture 2, we describe formation of disks and massive spheroids, including the growth of supermassive black holes, negative feedback in spheroids, the AGN-star formation connection, star formation rates at high redshift and the baryon fraction in galaxies.

  5. Statins Enhance Formation of Phagocyte Extracellular Traps

    Chow, Ohn A.; von Köckritz-Blickwede, Maren; Bright, A. Taylor; Hensler, Mary E.; Zinkernagel, Annelies S; Cogen, Anna L.; Gallo, Richard L.; Monestier, Marc; Wang, Yanming; Glass, Christopher K.; Nizet, Victor

    2010-01-01

    Statins are inhibitors of 3-hydroxy 3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme in cholesterol biosynthesis. Several recent clinico-epidemiologic studies have revealed that patients receiving statin therapy have reduced mortality associated with severe bacterial infection. Here we study pharmacological effect of statins on the innate immune capacity of phagocytic cells, focusing on the leading human bacterial pathogen Staphylococcus aureus. These studies revealed...

  6. Formative assessments as pedagogic tools

    Ashwin Kumar

    2013-01-01

    This article aims at presenting a state of the art status of formative assessment as a pedagogic tool. To this end, a brief developmental account of different modes of assessment over the last decades will be presented first. Then, formative assessment will be discussed in its constructivist guise. The present literature on assessment suggests that assessment for learning (formative assessment) not only represents an assessment tool but it also serves as a pedagogic tool to enhance learning a...

  7. Formation of granular sludge and its mechanism in enhanced process of biological phosphorus removal%强化生物除磷体系中颗粒污泥的形成及机理探讨

    王然登; 彭永臻; 吴昌永; 李晓玲; 马勇

    2011-01-01

    以实验室小试SBR反应器为载体接种普通活性污泥,研究了强化生物除磷系统对颗粒污泥形成的促进作用并探讨了其形成机理.试验结果发现:在生物脱氮运行阶段,SBR中的活性污泥能维持较稳定的絮体状态,平均SVI为138.9 ml·g-1;当系统转为生物除磷方式运行时,随着除磷效果的好转,反应器中的污泥逐渐转化为颗粒污泥,平均SVI降低至74.1 ml·g-1,颗粒污泥的平均粒径为0.8 mm.因此,SBR生物除磷系统有利于颗粒污泥的形成.试验发现在强化生物除磷系统厌氧释磷的过程中会有带正电的微粒大量生成,它们可以作为颗粒污泥的晶核吸附带负电的细胞体,进而促进颗粒污泥的形成.强化生物除磷颗粒污泥系统有着较为稳定的磷去除性能,除磷效率接近100%.%The promoting effect on the formation of granular sludge by inoculating activated sludge in the enhanced process of biological phosphorus removal was studied in a laboratory-scale sequencing batch reactor (SBR). The results showed that the activated sludge kept in stabilized flocculent state at biological denitrification stage, and the average SVI was 138.9 ml·g-1, while at biological de-phosphorus one the activated sludge flocs became granular sludge gradually as the performance of P removal became better. The average SVI decreased to 74.1 ml·g-1 and the average diameter of the granules was 0.8 mm. Therefore, the biological phosphorus removal process performed in SBR favored for the formation of granular sludge. Moreover, it was found that a lot of positive charged particles were formed with the release of phosphorus at the anaerobic stage in the biological de-phosphorus process. These particles could serve as the cores of granules to attract the negative charged cells and stimulate the granulation. The granular sludge system of enhancing biological de-phosphorus have an excellent ability for the removal of phosphorus. The average removal rate

  8. Bulge Formation

    Combes, F

    1999-01-01

    The currently discussed theories of bulge formation are reviewed, including the primordial scenario, where bulges form rapidly and then accrete disks, the secular scenario, where bulges are formed by dynamical evolution of disks through bars and galaxy interactions, and some combinations of both, where formation of bulges and disks are more continuous and interleaved. The various scenarios make specific predictions about the relative masses, angular momenta, colours, metallicities of bulges relative to disks, and the bulge-to-disk ratio as a function of time. Dynamical processes relevant to the formation of bulges (bar instabilities, mergers) are described and tested against observed statistics. Current data suggest a dynamical feedback from gravitational instabilities in bulge and disk formation. It is very difficult to discriminate between the various scenarios from surveys at z=0 only, and observations at high redshift are presently the best hope for large progress.

  9. Star formation

    Theoretical models of star formation are discussed beginning with the earliest stages and ending in the formation of rotating, self-gravitating disks or rings. First a model of the implosion of very diffuse gas clouds is presented which relies upon a shock at the edge of a galactic spiral arm to drive the implosion. Second, models are presented for the formation of a second generation of massive stars in such a cloud once a first generation has formed. These models rely on the ionizing radiation from massive stars or on the supernova shocks produced when these stars explode. Finally, calculations of the gravitational collapse of rotating clouds are discussed with special focus on the question of whether rotating disks or rings are the result of such a collapse. 65 references

  10. Galaxy Formation

    Sparre, Martin

    Galaxy formation is an enormously complex discipline due to the many physical processes that play a role in shaping galaxies. The objective of this thesis is to study galaxy formation with two different approaches: First, numerical simulations are used to study the structure of dark matter and how...... galaxies form stars throughout the history of the Universe, and secondly it is shown that observations of gamma-ray bursts (GRBs) can be used to probe galaxies with active star formation in the early Universe. A conclusion from the hydrodynamical simulations is that the galaxies from the stateof...... important, since it helps constraining chemical evolution models at high redshift. A new project studying how the population of galaxies hosting GRBs relate to other galaxy population is outlined in the conclusion of this thesis. The core of this project will be to quantify how the stellar mass function of...

  11. EDITORIAL: Enhancing nanolithography Enhancing nanolithography

    Demming, Anna

    2012-01-01

    interfering laser beams. The interference gave rise to a periodic line-like pattern in the intensity distribution of the incident field. In addition, the silica spheres cause enhancements to the incident field that result in the formation of patterns of craters, cavities and holes in the PEDOT-PSS. The researchers confirm the viability of their fabrication process with Mie scattering theory calculations. The technique has a number of advantages over previous methods for creating nanoporous structures in PEDOT-PSS, including efficiency, high-resolution and low cost as a clean room is not required. The stage is set for more technological developments as innovations in lithography and combinations with other techniques continue to play a leading role in high-resolution patterning and fabrication at the nanoscale. References [1] Grigorescu A E and Hagen C W 2009 Nanotechnology 20 292001 [2] Lin B J 1975 J. Vac. Sci. Technol. 12 1317-20 [3] Yuan D, Lasagni A, Hendricks J L, Martin D C and Das S 2012 Nanotechnology 23 015304 [4] Kim S H, Lee K-D, Kim J-Y, Kwon M-K and Park S-J 2007 Nanotechnology 18 055306 [5] Yu J, Ippolito S J, Wlodarski W, Strano M and Kalantar-Zadeh K 2010 Nanotechnology 21 265502 [6] Yang Y, Tanemura M, Huang Z, Jiang D, Li Z-Y, Huang Y-P, Kawamura G, Yamaguchi K and Nogami M 2010 Nanotechnology 21 325701 [7] Cade N I, Ritman-Meer T, Kwakwa K A and Richards D 2009 Nanotechnology 20 285201

  12. Isothermal Martensite Formation

    Villa, Matteo

    Isothermal (i.e. time dependent) martensite formation in steel was first observed in the 40ies of the XXth century and is still treated as an anomaly in the description of martensite formation which is considered as a-thermal (i.e. independent of time). Recently, the clarification of the mechanism...... leading to isothermal kinetics acquired new practical relevance because of the identification of isothermal martensite formation as the most likely process responsible for enhanced performances of sub-zero Celsius treated high carbon steel products. In the present work, different iron based alloys are...... chosen to investigate time dependent martensite formation. Among them, a Fe-11wt%Ni-0.6wt%C model alloy and Fe-1.6wt%Cr-1wt%C (AISI 52100), Fe-17wt%Cr-7wt%Ni (AISI 631) and Fe-16wt%Cr-5wt%Ni (AISI 630) commercial steels. The investigation was performed with in situ magnetometry, dilatometry, synchrotron...

  13. Formative assessments as pedagogic tools

    Ashwin Kumar

    2013-03-01

    Full Text Available This article aims at presenting a state of the art status of formative assessment as a pedagogic tool. To this end, a brief developmental account of different modes of assessment over the last decades will be presented first. Then, formative assessment will be discussed in its constructivist guise. The present literature on assessment suggests that assessment for learning (formative assessment not only represents an assessment tool but it also serves as a pedagogic tool to enhance learning and thinking. It has also gone to lengths to affect the design of classroom tasks and activities. Attempts have been made to delineate the underlying principles of formative assessment which can be used to picture the formation process of learners’ knowledge and development. Subsequently, alternative assessment techniques of which the present article will give an account have been suggested by scholars to operationalize these principles.

  14. Cement Formation

    Telschow, Samira; Jappe Frandsen, Flemming; Theisen, Kirsten;

    2012-01-01

    Cement production has been subject to several technological changes, each of which requires detailed knowledge about the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including an...... overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in cement production, is provided. Clinker formations by solid state reactions, solid−liquid and liquid...

  15. Isolating Triggered Star Formation

    Barton, Elizabeth J.; Arnold, Jacob A.; /UC, Irvine; Zentner, Andrew R.; /KICP, Chicago /Chicago U., EFI; Bullock, James S.; /UC, Irvine; Wechsler, Risa H.; /KIPAC, Menlo

    2007-09-12

    Galaxy pairs provide a potentially powerful means of studying triggered star formation from galaxy interactions. We use a large cosmological N-body simulation coupled with a well-tested semi-analytic substructure model to demonstrate that the majority of galaxies in close pairs reside within cluster or group-size halos and therefore represent a biased population, poorly suited for direct comparison to 'field' galaxies. Thus, the frequent observation that some types of galaxies in pairs have redder colors than 'field' galaxies is primarily a selection effect. We use our simulations to devise a means to select galaxy pairs that are isolated in their dark matter halos with respect to other massive subhalos (N= 2 halos) and to select a control sample of isolated galaxies (N= 1 halos) for comparison. We then apply these selection criteria to a volume-limited subset of the 2dF Galaxy Redshift Survey with M{sub B,j} {le} -19 and obtain the first clean measure of the typical fraction of galaxies affected by triggered star formation and the average elevation in the star formation rate. We find that 24% (30.5 %) of these L* and sub-L* galaxies in isolated 50 (30) h{sup -1} kpc pairs exhibit star formation that is boosted by a factor of {approx}> 5 above their average past value, while only 10% of isolated galaxies in the control sample show this level of enhancement. Thus, 14% (20 %) of the galaxies in these close pairs show clear triggered star formation. Our orbit models suggest that 12% (16%) of 50 (30) h{sup -1} kpc close pairs that are isolated according to our definition have had a close ({le} 30 h{sup -1} kpc) pass within the last Gyr. Thus, the data are broadly consistent with a scenario in which most or all close passes of isolated pairs result in triggered star formation. The isolation criteria we develop provide a means to constrain star formation and feedback prescriptions in hydrodynamic simulations and a very general method of understanding

  16. Towards App-based Formative Feedback to Support Summarizing Skills

    Van Rosmalen, Peter; Kester, Liesbeth; Boshuizen, Els

    2013-01-01

    Van Rosmalen, P., Kester, L., & Boshuizen, H. P. A. (2013, 18 September). Towards App‐based Formative Feedback to Support Summarizing Skills. Presentation given at ECTEL 2013: Workshop on Technology-Enhanced Formative Assessment (TEFA), Paphos, Cyprus.

  17. A clash of stressors and LTM formation

    de Caigny, Pascaline; Lukowiak, Ken

    2008-01-01

    Stress alters long-term memory formation sometimes enhancing its formation whilst at other times blocking it. It is unclear what the causal mechanisms are that allow stress to either enhance or suppress memory. We have made use of a relatively simple invertebrate model system to attempt to explore the causal mechanisms of how stress alters memory. Here we explore the consequences of presenting to the organism two different ecologically relevant stressors: detection of a predator and crowding....

  18. Tip enhancement

    Kawata, Satoshi

    2007-01-01

    This book discusses the recent advances in the area of near-field Raman scattering, mainly focusing on tip-enhanced and surface-enhanced Raman scattering. Some of the key features covered here are the optical structuring and manipulations, single molecule sensitivity, analysis of single-walled carbon nanotubes, and analytic applications in chemistry, biology and material sciences. This book also discusses the plasmonic materials for better enhancement, and optical antennas. Further, near-field microscopy based on second harmonic generation is also discussed. Chapters have been written by some of the leading scientists in this field, who present some of their recent work in this field.·Near-field Raman scattering·Tip-enhanced Raman spectroscopy·Surface-enhanced Raman spectroscopy·Nano-photonics·Nanoanalysis of Physical, chemical and biological materials beyond the diffraction limits·Single molecule detection

  19. Melatonin enhances antioxidative enzyme gene expression (CAT, GPx, SOD), prevents their UVR-induced depletion, and protects against the formation of DNA damage (8-hydroxy-2'-deoxyguanosine) in ex vivo human skin.

    Fischer, Tobias W; Kleszczyński, Konrad; Hardkop, Lena H; Kruse, Nathalie; Zillikens, Detlef

    2013-04-01

    UV radiation (UVR) induces serious structural and functional alterations in human skin leading to skin aging and carcinogenesis. Reactive oxygen species are key players in UVR-mediated photodamage and induce the DNA-base-oxidized, intermediate 8-hydroxy-2'-deoxyguanosine (8-OHdG). Herein, we report the protective action of melatonin against UVR-induced 8-OHdG formation and depletion of antioxidative enzymes using ex vivo human full-thickness skin exposed to UVR in a dose (0, 100, 300 mJ/cm(2))- and time-dependent manner (0, 24, 48 hr post-UVR). Dynamics of depletion of antioxidative enzymes including catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD), or 8-OHdG formation were studied by real-time PCR and immunofluorescence/immunohistochemical staining. UVR-treated skin revealed significant and immediate (0 hr 300 mJ/cm(2)) reduction of gene expression, and this effect intensified within 24 hr post-UVR. Simultaneous increase in 8-OHdG-positive keratinocytes occurred already after 0 hr post-UVR reaching 71% and 99% up-regulation at 100 and 300 mJ/cm(2), respectively (P DNA protectant against UVR-induced oxidative damage in human skin. PMID:23110400

  20. Postoperative enhancement

    The use of contrast agents in MR imaging and CT was compared in the postoperative state in a clinical series and an animal model and was found to vary in two ways. First, gadolinium appeared to be more sensitive than iodinated contrast agent in CT. Specifically, enhancement was noted earlier within the 1st week and later after several months than enhancement with CT. Second, because of the evolution of hemoglobin breakdown products, MR images became increasingly more difficult to interpret after a few days due to residual blood at the operative site. With CT, the visualization of blood diminished with time. In conclusion, the temporal evolution of contrast enhancement in MR imaging and CT is roughly parallel, although it may be even more important in MR to image as early as clinically possible in the postoperative state. Conversely, in the long-term postoperative state, residual normal postoperative enhancement can be seen with contrast-enhanced MR imaging when these changes will no longer be visible with contrast-enhanced CT

  1. Enhancement of DNA repair using topical T4 endonuclease V does not inhibit melanoma formation in Cdk4(R24C/R24C)/Tyr-Nras(Q61K) mice following neonatal UVR.

    Hacker, Elke; Muller, H Konrad; Hayward, Nicholas; Fahey, Paul; Walker, Graeme

    2010-02-01

    To further investigate the use of DNA repair-enhancing agents for skin cancer prevention, we treated Cdk4(R24C/R24C)/Nras(Q61K) mice topically with the T4 endonuclease V DNA repair enzyme (known as Dimericine) immediately prior to neonatal ultraviolet radiation (UVR) exposure, which has a powerful effect in exacerbating melanoma development in the mouse model. Dimericine has been shown to reduce the incidence of basal-cell and squamous cell carcinoma. Unexpectedly, we saw no difference in penetrance or age of onset of melanoma after neonatal UVR between Dimericine-treated and control animals, although the drug reduced DNA damage and cellular proliferation in the skin. Interestingly, epidermal melanocytes removed cyclobutane pyrimidine dimers (CPDs) more efficiently than surrounding keratinocytes. Our study indicates that neonatal UVR-initiated melanomas may be driven by mechanisms other than solely that of a large CPD load and/or their inefficient repair. This is further suggestive of different mechanisms by which UVR may enhance the transformation of keratinocytes and melanocytes. PMID:19788533

  2. Speech enhancement

    Benesty, Jacob; Chen, Jingdong

    2006-01-01

    We live in a noisy world! In all applications (telecommunications, hands-free communications, recording, human-machine interfaces, etc.) that require at least one microphone, the signal of interest is usually contaminated by noise and reverberation. As a result, the microphone signal has to be ""cleaned"" with digital signal processing tools before it is played out, transmitted, or stored.This book is about speech enhancement. Different well-known and state-of-the-art methods for noise reduction, with one or multiple microphones, are discussed. By speech enhancement, we mean not only noise red

  3. LASIK enhancements.

    Durrie, D S; Vande Garde, T L

    2000-01-01

    As the field of refractive surgery continues to evolve, an increasing number of surgical options are available for LASIK enhancements. Nonetheless, older methods such as AK continue to play an important role in enhancement procedures. Improvements in instruments and techniques allow for previously made LASIK flaps to be safely lifted for additional myopic or hyperopic ablations. Newer methods such as Intacs placement provide an effective option for patients who are not good candidates for further ablative procedures. These advancements allow refractive surgeons to treat a wider range of myopia, hyperopia, and astigmatism effectively in eyes with a history of LASIK surgery. PMID:10941651

  4. Double-stranded DNA-templated cleavage of oligonucleotides containing a P3'->N5' linkage triggered by triplex formation: the effects of chemical modifications and remarkable enhancement in reactivity.

    Ito, Kosuke Ramon; Kodama, Tetsuya; Tomizu, Masaharu; Negoro, Yoshinori; Orita, Ayako; Osaki, Tomohisa; Hosoki, Noritsugu; Tanaka, Takaya; Imanishi, Takeshi; Obika, Satoshi

    2010-11-01

    We recently reported double-stranded DNA-templated cleavage of oligonucleotides as a sequence-specific DNA-detecting method. In this method, triplex-forming oligonucleotides (TFOs) modified with 5'-amino-2',4'-BNA were used as a DNA-detecting probe. This modification introduced a P3'→N5' linkage (P-N linkage) in the backbone of the TFO, which was quickly cleaved under acidic conditions when it formed a triplex. The prompt fission of the P-N linkage was assumed to be driven by a conformational strain placed on the linkage upon triplex formation. Therefore, chemical modifications around the P-N linkage should change the reactivity by altering the microenvironment. We synthesized 5'-aminomethyl type nucleic acids, and incorporated them into TFOs instead of 5'-amino-2',4'-BNA to investigate the effect of 5'-elongation. In addition, 2',4'-BNA/LNA or 2',5'-linked DNA were introduced at the 3'- and/or 5'-neighboring residues of 5'-amino-2',4'-BNA to reveal neighboring residual effects. We evaluated the triplex stability and reaction properties of these TFOs, and found out that chemical modifications around the P-N linkage greatly affected their reaction properties. Notably, 2',5'-linked DNA at the 3' position flanking 5'-amino-2',4'-BNA brought significantly higher reactivity, and we succeeded in indicating that a TFO with this modification is promising as a DNA analysis tool. PMID:20615902

  5. Biological Mechanisms Underlying the Ultraviolet Radiation-Induced Formation of Skin Wrinkling and Sagging I: Reduced Skin Elasticity, Highly Associated with Enhanced Dermal Elastase Activity, Triggers Wrinkling and Sagging

    Genji Imokawa

    2015-04-01

    Full Text Available The repetitive exposure of skin to ultraviolet B (UVB preferentially elicits wrinkling while ultraviolet A (UVA predominantly elicits sagging. In chronically UVB or UVA-exposed rat skin there is a similar tortuous deformation of elastic fibers together with decreased skin elasticity, whose magnitudes are greater in UVB-exposed skin than in UVA-exposed skin. Comparison of skin elasticity with the activity of matrix metalloproteinases (MMPs in the dermis of ovariectomized rats after UVB or UVA irradiation demonstrates that skin elasticity is more significantly decreased in ovariectomized rats than in sham-operated rats, which is accompanied by a reciprocal increase in elastase activity but not in the activities of collagenases I or IV. Clinical studies using animal skin and human facial skin demonstrated that topical treatment with a specific inhibitor or an inhibitory extract of skin fibroblast-derived elastase distinctly attenuates UVB and sunlight-induced formation of wrinkling. Our results strongly indicated that the upregulated activity of skin fibroblast-derived elastase plays a pivotal role in wrinkling and/or sagging of the skin via the impairment of elastic fiber configuration and the subsequent loss of skin elasticity.

  6. Double-stranded DNA-templated cleavage of oligonucleotides containing a P3′→N5′ linkage triggered by triplex formation: the effects of chemical modifications and remarkable enhancement in reactivity

    Ito, Kosuke Ramon; Kodama, Tetsuya; Tomizu, Masaharu; Negoro, Yoshinori; Orita, Ayako; Osaki, Tomohisa; Hosoki, Noritsugu; Tanaka, Takaya; Imanishi, Takeshi; Obika, Satoshi

    2010-01-01

    We recently reported double-stranded DNA-templated cleavage of oligonucleotides as a sequence-specific DNA-detecting method. In this method, triplex-forming oligonucleotides (TFOs) modified with 5′-amino-2′,4′-BNA were used as a DNA-detecting probe. This modification introduced a P3′→N5′ linkage (P–N linkage) in the backbone of the TFO, which was quickly cleaved under acidic conditions when it formed a triplex. The prompt fission of the P–N linkage was assumed to be driven by a conformational strain placed on the linkage upon triplex formation. Therefore, chemical modifications around the P–N linkage should change the reactivity by altering the microenvironment. We synthesized 5′-aminomethyl type nucleic acids, and incorporated them into TFOs instead of 5′-amino-2′,4′-BNA to investigate the effect of 5′-elongation. In addition, 2′,4′-BNA/LNA or 2′,5′-linked DNA were introduced at the 3′- and/or 5′-neighboring residues of 5′-amino-2′,4′-BNA to reveal neighboring residual effects. We evaluated the triplex stability and reaction properties of these TFOs, and found out that chemical modifications around the P–N linkage greatly affected their reaction properties. Notably, 2′,5′-linked DNA at the 3′ position flanking 5′-amino-2′,4′-BNA brought significantly higher reactivity, and we succeeded in indicating that a TFO with this modification is promising as a DNA analysis tool. PMID:20615902

  7. Advanced reservoir characterization in the Antelope Shale to establish the viability of CO{sub 2} enhanced oil recovery in California`s Monterey Formation siliceous shales. Annual report, February 12, 1996--February 11, 1997

    Toronyi, R.M.

    1997-12-01

    The Buena Vista Hills field is located about 25 miles southwest of Bakersfield, in Kern County, California, about two miles north of the city of Taft, and five miles south of the Elk Hills field. The Antelope Shale zone was discovered at the Buena Vista Hills field in 1952, and has since been under primary production. Little research was done to improve the completion techniques during the development phase in the 1950s, so most of the wells are completed with about 1000 ft of slotted liner. The proposed pilot consists of four existing producers on 20 acre spacing with a new 10 acre infill well drilled as the pilot CO{sub 2} injector. Most of the reservoir characterization of the first phase of the project will be performed using data collected in the pilot pattern wells. This is the first annual report of the project. It covers the period February 12, 1996 to February 11, 1997. During this period the Chevron Murvale 653Z-26B well was drilled in Section 26-T31S/R23E in the Buena Vista Hills field, Kern County, California. The Monterey Formation equivalent Brown and Antelope Shales were continuously cored, the zone was logged with several different kinds of wireline logs, and the well was cased to a total depth of 4907 ft. Core recovery was 99.5%. Core analyses that have been performed include Dean Stark porosity, permeability and fluid saturations, field wettability, anelastic strain recovery, spectral core gamma, profile permeametry, and photographic imaging. Wireline log analysis includes mineral-based error minimization (ELAN), NMR T2 processing, and dipole shear wave anisotropy. A shear wave vertical seismic profile was acquired after casing was set and processing is nearly complete.

  8. Advanced reservoir characterization in the Antelope Shale to establish the viability of CO2 enhanced oil recovery in California`s Monterey Formation siliceous shales. Annual report, February 7, 1997--February 6, 1998

    Morea, M.F.

    1998-06-01

    The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a CO{sub 2} enhanced oil recovery project in the antelope Shale in Buena Vista Hills Field. The proposed pilot consists of four existing producers on 20 acre spacing with a new 10 acre infill well drilled as the pilot CO{sub 2} injector. Most of the reservoir characterization during Phase 1 of the project will be performed using data collected in the pilot pattern wells. During this period the following tasks have been completed: laboratory wettability; specific permeability; mercury porosimetry; acoustic anisotropy; rock mechanics analysis; core description; fracture analysis; digital image analysis; mineralogical analysis; hydraulic flow unit analysis; petrographic and confocal thin section analysis; oil geochemical fingerprinting; production logging; carbon/oxygen logging; complex lithologic log analysis; NMR T2 processing; dipole shear wave anisotropy logging; shear wave vertical seismic profile processing; structural mapping; and regional tectonic synthesis. Noteworthy technological successes for this reporting period include: (1) first (ever) high resolution, crosswell reflection images of SJV sediments; (2) first successful application of the TomoSeis acquisition system in siliceous shales; (3) first detailed reservoir characterization of SJV siliceous shales; (4) first mineral based saturation algorithm for SJV siliceous shales, and (5) first CO{sub 2} coreflood experiments for siliceous shale. Preliminary results from the CO{sub 2} coreflood experiments (2,500 psi) suggest that significant oil is being produced from the siliceous shale.

  9. Characterization of HfO{sub x}N{sub y} thin film formation by in-situ plasma enhanced atomic layer deposition using NH{sub 3} and N{sub 2} plasmas

    Lee, Young Bok; Oh, Il-Kwon; Cho, Edward Namkyu; Moon, Pyung; Kim, Hyungjun; Yun, Ilgu, E-mail: iyun@yonsei.ac.kr

    2015-09-15

    Highlights: • Analysis of PE-ALD grown HfON thin films using NH{sub 3} and N{sub 2} plasmas. • PE-ALD grown HfON film showed high dielectric constant and thermal stability. • PE-ALD grown HfON film suppressed the interfacial layer. • High leakage current of HfON film was caused by bandgap lowing and band offset. - Abstract: The structural and electrical characteristics of in-situ nitrogen-incorporated plasma enhanced atomic layer deposition (PE-ALD) HfO{sub x}N{sub y} thin films using NH{sub 3} and N{sub 2} plasmas as reactants were comparatively studied. The HfO{sub x}N{sub y} test structures prepared using NH{sub 3} and N{sub 2} plasmas were analyzed by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and high resolution transmission electron microscopy (HR-TEM) to investigate the chemical composition, crystallinity, and cross-sectional layers including the interfacial layer, respectively. By utilizing NH{sub 3} and N{sub 2} plasmas, the nitrogen-incorporated HfO{sub x}N{sub y} thin films fabricated by in-situ PE-ALD showed a high dielectric constant and thermal stability, which suppresses the interfacial layer and increases the crystallization temperature. The high leakage current densities of the HfO{sub x}N{sub y} thin film test structures fabricated using NH{sub 3} and N{sub 2} plasmas caused by lowering the energy bandgap and band offset are related to the Hf−N bond ratio and dielectric constant.

  10. XML-Based DICOM Data Format

    Yu, Cong; Yao, Zhihong

    2009-01-01

    To enhance the readability, improve the structure, and facilitate the sharing of digital imaging and communications in medicine (DICOM) files, this research proposed one kind of XML-based DICOM data format. Because XML Schema offers great flexibility for expressing constraints on the content model of elements, we used it to describe the new format, thus making it consistent with the one originally defined by DICOM. Meanwhile, such schemas can be used in the creation and validation of the XML-...

  11. Consensus formation on coevolving networks: groups' formation and structure

    We study the effect of adaptivity on a social model of opinion dynamics and consensus formation. We analyse how the adaptivity of the network of contacts between agents to the underlying social dynamics affects the size and topological properties of groups and the convergence time to the stable final state. We find that, while on static networks these properties are determined by percolation phenomena, on adaptive networks the rewiring process leads to different behaviors: adaptive rewiring fosters group formation by enhancing communication between agents of similar opinion, though it also makes possible the division of clusters. We show how the convergence time is determined by the characteristic time of link rearrangement. We finally investigate how the adaptivity yields nontrivial correlations between the internal topology and the size of the groups of agreeing agents

  12. What Makes a Good Format: Frameworks for Evaluating the Effect of Graphic Risk Formats on Consumers’ Risk-Related Behavior

    Civan, Andrea; Doctor, Jason N.; Wolf, Fredric M.

    2005-01-01

    The format in which risk information is presented has a fundamental influence on the quality of risk communication with health consumers. Graphic formats might enhance the risk communication process, but we know little about how these formats affect risk-related behavior. Based on a review of literature within and outside the medical domain, we present four useful frameworks for evaluating the effects of graphic format on risk-related behavior.

  13. Formate Formation and Formate Conversion in Biological Fuels Production

    Bryan R. Crable

    2011-01-01

    Full Text Available Biomethanation is a mature technology for fuel production. Fourth generation biofuels research will focus on sequestering CO2 and providing carbon-neutral or carbon-negative strategies to cope with dwindling fossil fuel supplies and environmental impact. Formate is an important intermediate in the methanogenic breakdown of complex organic material and serves as an important precursor for biological fuels production in the form of methane, hydrogen, and potentially methanol. Formate is produced by either CoA-dependent cleavage of pyruvate or enzymatic reduction of CO2 in an NADH- or ferredoxin-dependent manner. Formate is consumed through oxidation to CO2 and H2 or can be further reduced via the Wood-Ljungdahl pathway for carbon fixation or industrially for the production of methanol. Here, we review the enzymes involved in the interconversion of formate and discuss potential applications for biofuels production.

  14. Prediction of tar ball formation

    Khelifa, A.; Gamble, L. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Division, Environmental Technology Centre, Science and Technology Branch

    2006-07-01

    The presence of small tar balls ranging in size from less than a millimetre to 60 centimetres have been observed during cleanup assessment operations following accidental oil spills on water. The tar balls are composed of heavy oil residues and suspended particulate matter (SPM) from the water column. They can be found on shorelines, settled on the seafloor and floating at or near the water surface. Their abundance on the shorelines varies from site to site and depends on the conditions of the spill and mixing conditions. Aggregation between SPM and micro-sized oil droplets occurs naturally in coastal waters and enhances the dispersion of spilled oil. Although tar balls are among the important end states of spilled oil in the marine environment, no model exists to estimate the percentage of the spilled oil that becomes tar balls. This paper offered some insight into the modeling of tar ball formation. Current modeling understanding of oil-SPM aggregate formation was used to predict tar ball formation. The formation of oil droplets was examined with respect to a range of conditions under which the formation of large droplets is expected. The role of aggregation was then presented to demonstrate the effects of concentration and type of SPM on the buoyancy of tar balls. Good agreement was found between modeling results and field data reported in the literature regarding the size and density of tar balls. Oil viscosity and mixing energy were found to be the main factors controlling the formation of tar balls. The aggregation of tar balls with SPM and shoreline material results in significant increases or decreases in density, depending on the type and concentration of SPM. 42 refs., 2 tabs., 6 figs.

  15. Magnetic Diffusion in Star Formation

    Basu, Shantanu

    2010-01-01

    Magnetic diffusion plays a vital role in star formation. We trace its influence from interstellar cloud scales down to star-disk scales. On both scales, we find that magnetic diffusion can be significantly enhanced by the buildup of strong gradients in magnetic field structure. Large scale nonlinear flows can create compressed cloud layers within which ambipolar diffusion occurs rapidly. However, in the flux-freezing limit that may be applicable to photoionized molecular cloud envelopes, supersonic motions can persist for long times if driven by an externally generated magnetic field that corresponds to a subcritical mass-to-flux ratio. In the case of protostellar accretion, rapid magnetic diffusion (through Ohmic dissipation with additional support from ambipolar diffusion) near the protostar causes dramatic magnetic flux loss. By doing so, it also allows the formation of a centrifugal disk, thereby avoiding the magnetic braking catastrophe.

  16. Speech Enhancement

    Benesty, Jacob; Jensen, Jesper Rindom; Christensen, Mads Græsbøll;

    and their performance bounded and assessed in terms of noise reduction and speech distortion. The book shows how various filter designs can be obtained in this framework, including the maximum SNR, Wiener, LCMV, and MVDR filters, and how these can be applied in various contexts, like in single......Speech enhancement is a classical problem in signal processing, yet still largely unsolved. Two of the conventional approaches for solving this problem are linear filtering, like the classical Wiener filter, and subspace methods. These approaches have traditionally been treated as different classes...

  17. Bibliometric-enhanced Information Retrieval

    Mayr, Philipp; Larsen, Birger; Schaer, Philipp; Mutschke, Peter

    2013-01-01

    Bibliometric techniques are not yet widely used to enhance retrieval processes in digital libraries, although they offer value-added effects for users. In this workshop we will explore how statistical modelling of scholarship, such as Bradfordizing or network analysis of coauthorship network, can improve re-trieval services for specific communities, as well as for large, cross-domain col-lections. This workshop aims to raise awareness of the missing link between in-formation retrieval (IR) and bibliometrics/scientometrics and to create a common ground for the incorporation of bibliometric-enhanced services into retrieval at the digital library interface.

  18. Interactions, star formation and AGN activity

    Li, Cheng; Heckman, Timothy M; White, Simon D M; Jing, Y P

    2007-01-01

    It has long been known that galaxy interactions are associated with enhanced star formation. In a companion paper, we explored this connection by applying a variety of statistics to SDSS data. In particular, we showed that specific star formation rates of galaxies are higher if they have close neighbours. Here we apply exactly the same techniques to AGN in the survey, showing that close neighbours are not associated with any similar enhancement of nuclear activity. Star formation is enhanced in AGN with close neighbours in exactly the same way as in inactive galaxies, but the accretion rate onto the black hole, as estimated from the extinction-corrected [O III] luminosity, is not influenced by the presence or absence of companions. Previous work has shown that galaxies with more strongly accreting black holes contain more young stars in their inner regions. This leads us to conclude that star formation induced by a close companion and star formation associated with black hole accretion are distinct events. Th...

  19. Star Formation in Galaxies

    1987-01-01

    Topics addressed include: star formation; galactic infrared emission; molecular clouds; OB star luminosity; dust grains; IRAS observations; galactic disks; stellar formation in Magellanic clouds; irregular galaxies; spiral galaxies; starbursts; morphology of galactic centers; and far-infrared observations.

  20. Nanosecond electric pulses penetrate the nucleus and enhance speckle formation

    Chen, N.; Garner, A L; Chen, G.; Jing, Y.; Deng, Y.; Swanson, R J; Kolb, J. F.; Beebe, S. J.; Joshi, R. P.; Schoenbach, K H

    2007-01-01

    Nanosecond electric pulses generate nanopores in the interior membranes of cells and modulate cellular functions. Here, we used confocal microscopy and flow cytometry to observe Smith antigen antibody (Y12) binding to nuclear speckles, known as small nuclear ribonucleoprotein particles (snRNPs) or intrachromatin granule clusters (IGCs), in Jurkat cells following one or five 10 ns, 150 kV/cm pulses. Using confocal microscopy and flow cytometry, we observed changes in nuclear speckle labeling t...

  1. Technology Enhanced Formative Assessment for 21st Century Learning

    Spector, J. Michael; Ifenthaler, Dirk; Sampson, Demetrios; Yang, Lan; Mukama, Evode; Warusavitarana, Amali; Dona, Kulari Lokuge; Eichhorn, Koos; Fluck, Andrew; Huang, Ronghuai; Bridges, Susan; Lu, Jiingyan; Ren, Youqun; Gui, Xiaoqing; Deneen, Christopher C.; San Diego, Jonathan; Gibson, David C.

    2016-01-01

    This paper is based on the deliberations of the Assessment Working Group at EDUsummIT 2015 in Bangkok, Thailand. All of the members of Thematic Working Group 5 (TWG5) have contributed to this synthesis of potentials, concerns and issues with regard to the role of technology in assessment as, for and of learning in the 21st century. The group…

  2. Technology-Enhanced Formative Assessment of Plant Identification

    Conejo, Ricardo; Garcia-Viñas, Juan Ignacio; Gastón, Aitor; Barros, Beatriz

    2016-01-01

    Developing plant identification skills is an important part of the curriculum of any botany course in higher education. Frequent practice with dried and fresh plants is necessary to recognize the diversity of forms, states, and details that a species can present. We have developed a web-based assessment system for mobile devices that is able to…

  3. Teamwork to Enhance Adapted Teaching and Formative Assessment

    Bjornsrud, Halvor; Engh, Roar

    2012-01-01

    This article has as its main focus the contextual factors connected with teachers' teamwork. Firstly, it deals with the question of how to create reflections among teachers on the topic of teamwork. Their written answers function as empirical data for researchers and also as contributions to the further professional development of teamwork.…

  4. Enhanced membrane pore formation by multimeric/oligomeric antimicrobial peptides.

    Arnusch, Christopher J; Branderhorst, Hilbert; de Kruijff, Ben; Liskamp, Rob M J; Breukink, Eefjan; Pieters, Roland J

    2007-11-20

    The pore-forming antibacterial peptide magainin 2 was made divalent, tetravalent, and octavalent via a copper(I)-mediated 1-3 dipolar cycloaddition reaction ("click" chemistry). This series of pore-forming compounds was tested in vitro for their ability to form pores in large unilamillar vesicles (LUVs). A large increase in the pore-forming capability was especially observed with the tetravalent and octavalent magainin compounds in the LUVs consisting of DOPC, and the octavalent magainin compound showed a marked increase with the DOPC/DOPG LUVs. Activity was observed in the low nanomolar range for these compounds. PMID:17944489

  5. Nanostructure formation enhances the activity of LPS-neutralizing peptides.

    Mas-Moruno, C.; Cascales, L.; Cruz, L.J.; Mora, P.; Perez-Paya, E.; Albericio, F.

    2008-01-01

    Peptides that interact with lipopolysaccharide (LPS) can provide the basis for the development of new antisepsis agents. In this work, several LPS-neutralizing acyl peptides derived from LALF, BPI, and SAP were prepared, structurally characterized, and biologically evaluated. In all cases, peptides

  6. Skeletal myotube formation enhanced by electrospun polyurethane carbon nanotube scaffolds

    Sirivisoot S; Harrison BS

    2011-01-01

    Sirinrath Sirivisoot, Benjamin S Harrison Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Medical Center Boulevard, Winston-Salem, NC, USA Background: This study examined the effects of electrically conductive materials made from electrospun single- or multiwalled carbon nanotubes with polyurethane to promote myoblast differentiation into myotubes in the presence and absence of electrical stimulation. Methods and results: After electrical stimulation,...

  7. Professional Formation of Engineers: Enhancing the First Year Student Experience

    Goold, Eileen

    2015-01-01

    This paper reports on a study investigating engineering students’ perceptions of engineering practice and whether engineering students’ cognitive engagement benefits from bridging the gap between the technical issues in their education and the practical realities of modern engineering practice.

  8. Extracellular Xylella fastidiosa genomic DNA enhances biofilm formation in vitro

    Xylella fastidiosa (Xf) is a Gram negative, xylem-limited bacterium that causes Pierce’s Disease (PD) of grapevine, as well as other diseases of economically important crops and landscape plants. Many bacteria produce large amounts of extracellular DNA, which may function as a matrix component in b...

  9. Proposal for Using a Studio Format to Enhance Institutional Advancement

    Chance, Shannon

    2008-01-01

    Universities today need to become quicker on their toes. They must continually scan the environment and seize emerging opportunities--and institutional advancement must lead this effort. An unfortunate number of institutional advancement operations are ill equipped for the task at hand. Many suffer from high staff turnover and overly hierarchical…

  10. Telemetry-Enhancing Scripts

    Maimone, Mark W.

    2009-01-01

    Scripts Providing a Cool Kit of Telemetry Enhancing Tools (SPACKLE) is a set of software tools that fill gaps in capabilities of other software used in processing downlinked data in the Mars Exploration Rovers (MER) flight and test-bed operations. SPACKLE tools have helped to accelerate the automatic processing and interpretation of MER mission data, enabling non-experts to understand and/or use MER query and data product command simulation software tools more effectively. SPACKLE has greatly accelerated some operations and provides new capabilities. The tools of SPACKLE are written, variously, in Perl or the C or C++ language. They perform a variety of search and shortcut functions that include the following: Generating text-only, Event Report-annotated, and Web-enhanced views of command sequences; Labeling integer enumerations with their symbolic meanings in text messages and engineering channels; Systematic detecting of corruption within data products; Generating text-only displays of data-product catalogs including downlink status; Validating and labeling of commands related to data products; Performing of convenient searches of detailed engineering data spanning multiple Martian solar days; Generating tables of initial conditions pertaining to engineering, health, and accountability data; Simplified construction and simulation of command sequences; and Fast time format conversions and sorting.

  11. Star Formation for Predictive Primordial Galaxy Formation

    Milosavljevic, Milos

    2015-01-01

    The elegance of inflationary cosmology and cosmological perturbation theory ends with the formation of the first stars and galaxies, the initial sources of light that launched the phenomenologically rich process of cosmic reionization. Here we review the current understanding of early star formation, emphasizing unsolved problems and technical challenges. We begin with the first generation of stars to form after the Big Bang and trace how they influenced subsequent star formation. The onset of chemical enrichment coincided with a sharp increase in the overall physical complexity of star forming systems. Ab-initio computational treatments are just now entering the domain of the predictive and are establishing contact with local observations of the relics of this ancient epoch.

  12. Star Formation for Predictive Primordial Galaxy Formation

    Milosavljević, Miloš; Safranek-Shrader, Chalence

    The elegance of inflationary cosmology and cosmological perturbation theory ends with the formation of the first stars and galaxies, the initial sources of light that launched the phenomenologically rich process of cosmic reionization. Here we review the current understanding of early star formation, emphasizing unsolved problems and technical challenges. We begin with the first generation of stars to form after the Big Bang and trace how they influenced subsequent star formation. The onset of chemical enrichment coincided with a sharp increase in the overall physical complexity of star forming systems. Ab-initio computational treatments are just now entering the domain of the predictive and are establishing contact with local observations of the relics of this ancient epoch.

  13. Melatonin enhances mitochondrial ATP synthesis, reduces reactive oxygen species formation, and mediates translocation of the nuclear erythroid 2-related factor 2 resulting in activation of phase-2 antioxidant enzymes (γ-GCS, HO-1, NQO1) in ultraviolet radiation-treated normal human epidermal keratinocytes (NHEK).

    Kleszczyński, Konrad; Zillikens, Detlef; Fischer, Tobias W

    2016-09-01

    Melatonin is an ubiquitous molecule with a variety of functions including potent antioxidative properties. Due to its lipophilic character, it easily crosses cellular and intracellular membranes and reaches all subcellular organelles. Because of its ability to scavenge free radicals, melatonin protects against oxidative stress, for example, induced by ultraviolet radiation (UVR). Here, we investigated, in a dose-dependent (0, 10, 25, and 50 mJ/cm(2) ) and time-dependent (0, 4, 24, 48 hr post-UVR) manner, whether melatonin prevents the UVR-mediated alterations in ATP synthesis and the generation of reactive oxygen species (ROS) in normal human epidermal keratinocytes (NHEK). Additionally, we evaluated the molecular mechanism of action of melatonin with regard to activation of phase-2 antioxidative enzymes via nuclear erythroid 2-related factor (Nrf2). We found that (i) melatonin counteracted UVR-induced alterations in the ATP synthesis and reduced free radical formation; (ii) melatonin induced the translocation of Nrf2 transcription factor from the cytosol into the nucleus resulting in, (iii) melatonin enhanced gene expression of phase-2 antioxidative enzymes including γ-glutamylcysteine synthetase (γ-GCS), heme oxygenase-1 (HO-1), and NADPH: quinone dehydrogenase-1 (NQO1) representing an elevated antioxidative response of keratinocytes. These results suggest that melatonin not only directly scavenges ROS, but also significantly induces the activation of phase-2 antioxidative enzymes via the Nrf2 pathway uncovering a new action mechanism that supports the ability of keratinocytes to protect themselves from UVR-mediated oxidative stress. PMID:27117941

  14. Heart Disease Management by Women: Does Intervention Format Matter?

    Clark, Noreen M.; Janz, Nancy K.; Dodge, Julia A.; Lin, Xihong; Trabert, Britton L.; Kaciroti, Niko; Mosca, Lori; Wheeler, John R.; Keteyian, Steven

    2014-01-01

    A randomized controlled trial of two formats of a program (Women Take PRIDE) to enhance management of heart disease by patients was conducted. Older women (N = 575) were randomly assigned to a group or self-directed format or to a control group. Data regarding symptoms, functional health status, and weight were collected at baseline and at 4, 12,…

  15. Towards App-based Formative Feedback to Support Summarizing Skills

    Van Rosmalen, Peter; Kester, Liesbeth; Boshuizen, Els

    2013-01-01

    Van Rosmalen, P., Kester, L., & Boshuizen, H. P. A. (2013). Towards App‐based Formative Feedback to Support Summarizing Skills. ECTEL 2013: Workshop on Technology-Enhanced Formative Assessment (TEFA). September, 17-18, 2013, Paphos, Cyprus. Available online at: http://www.kbs.uni-hannover.de/tefa201

  16. Secondary Organic Aerosol Formation From Select Volatile Organic Compounds

    Chen, Chia-Li

    2015-01-01

    This thesis enhances our understanding of secondary organic aerosol (SOA) formation from select anthropogenic sources including polycyclic aromatic hydrocarbons (PAHs), PAHs mixed with m-xylene and an atmospheric surrogate, and unburned whole gasoline vapors. Major SOA chemical characteristics and physical properties were explored along with SOA formation within the UCR CE-CERT environmental chamber. SOA formation was significant for all three PAHs precursors during photooxidation under high ...

  17. The Conic Benchmark Format

    Friberg, Henrik A.

    This document constitutes the technical reference manual of the Conic Benchmark Format with le extension: .cbf or .CBF. It unies linear, second-order cone (also known as conic quadratic) and semidenite optimization with mixed-integer variables. The format has been designed with benchmark libraries...... in mind, and therefore focuses on compact and easily parsable representations. The problem structure is separated from the problem data, and the format moreover facilitate benchmarking of hotstart capability through sequences of changes....

  18. Data format translation routines

    To enable the effective connection of several dissimilar computers into a network, modification of the data being passed from one computer to another may become necessary. This document describes a package of routines which permit the translation of data in PDP-8 formats to PDP-11 or DECsystem-10 formats or from PDP-11 format to DECsystem-10 format. Additional routines are described which permit the effective use of the translation routines in the environment of the Fusion Energy Division (FED) network and the Elmo Bumpy Torus (EBT) data base

  19. Data format translation routines

    Burris, R.D.

    1981-02-01

    To enable the effective connection of several dissimilar computers into a network, modification of the data being passed from one computer to another may become necessary. This document describes a package of routines which permit the translation of data in PDP-8 formats to PDP-11 or DECsystem-10 formats or from PDP-11 format to DECsystem-10 format. Additional routines are described which permit the effective use of the translation routines in the environment of the Fusion Energy Division (FED) network and the Elmo Bumpy Torus (EBT) data base.

  20. ENDF/B format

    This document is a brief user's description of the format of ENDF/B. This format, originally designed for the US Evaluated Nuclear Data File, is recommended for international use. This summary is an aid to customers of the IAEA Nuclear Data Section when receiving data retrievals in ENDF/B format. For more detailed information the report BNL-NCS-50496 (ENDF 102) should be consulted. An Appendix to the present document gives a summary of the format differences between ENDF/B-4 and ENDF/B-5. (author)

  1. Formative Assessment in Context

    Oxenford-O'Brian, Julie

    2013-01-01

    This dissertation responds to critical gaps in current research on formative assessment practice which could limit successful implementation of this practice within the K-12 classroom context. The study applies a socio cultural perspective of learning to interpret a cross-case analysis of formative assessment practice occurring during one…

  2. When efficient star formation drives cluster formation

    Parmentier, G

    2008-01-01

    We investigate the impact of the star formation efficiency in cluster forming cores on the evolution of the mass in star clusters over the age range 1-100Myr, when star clusters undergo their infant weight-loss/mortality phase. Assuming a constant formation rate of gas-embedded clusters and a weak tidal field, we show that the ratio between the total mass in stars bound to the clusters over that age range and the total mass in stars initially formed in gas-embedded clusters is a strongly increasing function of the averaged local SFE, with little influence from any assumed core mass-radius relation. Our results suggest that, for young starbursts with estimated tidal field strength and known recent star formation history, observed cluster-to-star mass ratios, once corrected for the undetected clusters, constitute promising probes of the local SFE, without the need of resorting to gas mass estimates. Similarly, the mass ratio of stars which remain in bound clusters at the end of the infant mortality/weight-loss ...

  3. The FORMAT campaign in summer 2002

    Ordonez, C.; Steinbacher, M.; Dommen, J.; Prevot, A.S.H.

    2003-03-01

    Within the framework of the EC project FORMAT (Formaldehyde as a Tracer of Photooxidation in the Troposphere) the Laboratory of Atmospheric Chemistry participated in a field campaign in the Milan area dur-ing summer 2002. Ground and airborne based measurements of formaldehyde and other trace gases were performed in order to enhance the knowledge of the tropospheric distribution of formaldehyde and its influence in photochemical processes. (author)

  4. Formation of Compact Binaries in Globular Clusters

    Rappaport, Saul; Pfahl, Eric; Rasio, Fred; Podsiadlowski, Philipp

    2001-01-01

    We report here on two complementary population synthesis studies which relate directly to the formation and evolution of neutron star binaries in globular clusters. In the first, we compute the probability of retaining neutron stars in globular clusters, and quantitatively confirm the idea that the retention fraction for neutron stars born in binary systems is greatly enhanced over those born in isolated stars. However, the retention fraction may well be insufficient to explain the current po...

  5. Manuel UNIMARC format bibliographique

    2007-01-01

    This manual is the French translation of the second edition of UNIMARC Manual: bibliographic format published in English in 1994 and completed by 5 updates published from 1996 to 2005. This 5th French edition is composite. It reproduces identically a part of the 4th edition published in 2002 and, for the fields of the format modified in the Update 5, it offers a new more structured presentation. This is a handbook dedicated to French-speaking users of the UNIMARC format for bibliographic descriptions.

  6. Teaching Letter Formation.

    Graham, Steve; Madan, Avi J.

    1981-01-01

    The authors describe a remedial technique for teaching letter formation to students with handwriting difficulties. The approach blends traditional procedures (modeling, physical prompts, tracing, self correction, etc.) with cognitive behavior modification principles. (CL)

  7. Notes on Star Formation

    Krumholz, Mark R

    2015-01-01

    This book provides an introduction to the field of star formation at a level suitable for graduate students or advanced undergraduates in astronomy or physics. The structure of the book is as follows. The first two chapters begin with a discussion of observational techniques, and the basic phenomenology they reveal. The goal is to familiarize students with the basic techniques that will be used throughout, and to provide a common vocabulary for the rest of the book. The next five chapters provide a similar review of the basic physical processes that are important for star formation. Again, the goal is to provide a basis for what follows. The remaining chapters discuss star formation over a variety of scales, starting with the galactic scale and working down to the scales of individual stars and their disks. The book concludes with a brief discussion of the clearing of disks and the transition to planet formation. The book includes five problem sets, complete with solutions.

  8. Formation, dissolution and properties of surface nanobubbles

    Che, Zhizhao

    2016-01-01

    Surface nanobubbles are stable gaseous phases in liquids that form onto solid substrates. While their existence has been confirmed, there are many open questions related to their formation and dissolution processes along with their structure and properties, which are difficult to investigate experimentally. To address these issues, we carried out molecular dynamics simulations based on atomistic force-fields for systems comprised of water, air (N2 and O2), and a Highly Oriented Pyrolytic Graphite (HOPG) substrate. Our results provide insights into the formation/dissolution mechanisms of nanobubbles and estimates for their density, contact angle and surface tension. We found that the formation of nanobubbles is driven by an initial nucleation process of air molecules and the subsequent coalescence of the formed air clusters. The clusters form favorably on the substrate, which provides an enhanced stability to the clusters. In contrast, nanobubbles formed in the bulk move either randomly to the substrate and sp...

  9. Formation of Bulges

    Silk, J; Silk, Joseph; Bouwens, Rychard J.

    1998-01-01

    Bulges, often identified with the spheroidal component of a galaxy, have a complex pedigree. Massive bulges are generally red and old, but lower mass bulges have broader dispersions in color that may be correlated with disk colors. This suggests different formation scenarios. I will review possible formation sequences for bulges, describe the various signatures that distinguish these scenarios, and discuss implications for the high redshift universe.

  10. Tetrahydrofuran Clathrate Hydrate Formation

    Conrad, Heiko; Lehmkuhler, Felix; Sternemann, Christian; Sakko, Arto; Paschek, Dietmar; Simonelli, Laura; Huotari, Simo; Feroughi, Omid; Tolan, Metin; HÀmÀlÀinen, Keijo

    2009-01-01

    We report on the formation of tetrahydrofuran clathrate hydrate studied by x-ray Raman scattering measurements at the oxygen K edge. A comparison of x-ray Raman spectra measured from water-tetrahydrofuran mixtures and tetrahydrofuran hydrate at different temperatures supports stochastic hydrate formation models rather than models assuming hydrate precursors. This is confirmed by molecular dynamics simulations and density functional theory calculations of x-ray Raman spectra. In addition, chan...

  11. Plant Formate Dehydrogenase

    John Markwell

    2005-01-10

    The research in this study identified formate dehydrogenase, an enzyme that plays a metabolic role on the periphery of one-carbon metabolism, has an unusual localization in Arabidopsis thaliana and that the enzyme has an unusual kinetic plasticity. These properties make it possible that this enzyme could be engineered to attempt to engineer plants with an improved photosynthetic efficiency. We have produced transgenic Arabidopsis and tobacco plants with increased expression of the formate dehydrogenase enzyme to initiate further studies.

  12. Limits to Sensitivity in Laser Enhanced Ionization.

    Travis, J. C.

    1982-01-01

    Laser enhanced ionization (LEI) occurs when a tunable dye laser is used to excite a specific atomic population in a flame. Explores the origin of LEI's high sensitivity and identifies possible avenues to higher sensitivity by describing instrument used and experimental procedures and discussing ion formation/detection. (Author/JN)

  13. Innovative Solution to Video Enhancement

    2001-01-01

    Through a licensing agreement, Intergraph Government Solutions adapted a technology originally developed at NASA's Marshall Space Flight Center for enhanced video imaging by developing its Video Analyst(TM) System. Marshall's scientists developed the Video Image Stabilization and Registration (VISAR) technology to help FBI agents analyze video footage of the deadly 1996 Olympic Summer Games bombing in Atlanta, Georgia. VISAR technology enhanced nighttime videotapes made with hand-held camcorders, revealing important details about the explosion. Intergraph's Video Analyst System is a simple, effective, and affordable tool for video enhancement and analysis. The benefits associated with the Video Analyst System include support of full-resolution digital video, frame-by-frame analysis, and the ability to store analog video in digital format. Up to 12 hours of digital video can be stored and maintained for reliable footage analysis. The system also includes state-of-the-art features such as stabilization, image enhancement, and convolution to help improve the visibility of subjects in the video without altering underlying footage. Adaptable to many uses, Intergraph#s Video Analyst System meets the stringent demands of the law enforcement industry in the areas of surveillance, crime scene footage, sting operations, and dash-mounted video cameras.

  14. Formation peculiarities of tourism documentation

    Zhezhnych, Pavlo; Soprunyuk, Oksana

    2013-01-01

    The article describes formation peculiarities of tourism documentation, the role of tourism data consolidation for unified format creation and the the need to use existing software tools to handle tourism information, formation process of tourism documentation is presented.

  15. Molecules in star formation.

    Shu, F. H.

    The author reviews current ideas and models in the problem of star formation from molecular cloud cores that are relatively isolated from the influences of other forming stars. He discusses the time scales, flow dynamics, and density and temperature structures applicable to each of the four stages of the entire process: (1) formation of a magnetized cloud core by ambipolar diffusion and evolution to a pivotal state of gravomagneto catastrophe; (2) self-similar collapse of the pivotal configuration and the formation of protostars, disks, and pseudo-disks; (3) onset of a magnetocentrifugally driven, lightly ionized wind from the interaction of an accretion disk and the magnetosphere of the central star, and the driving of bipolar molecular outflows; (4) evolution of pre-main-sequence stars surrounded by dusty accretion disks. For each of these stages and processes, he considers the characteristics of the molecular diagnostics needed to investigate the crucial aspects of the observational problem.

  16. Meningococcal biofilm formation

    Lappann, M.; Haagensen, Janus Anders Juul; Claus, H.;

    2006-01-01

    We show that in a standardized in vitro flow system unencapsulated variants of genetically diverse lineages of Neisseria meningitidis formed biofilms, that could be maintained for more than 96 h. Biofilm cells were resistant to penicillin, but not to rifampin or ciprofloxacin. For some strains......, microcolony formation within biofilms was observed. Microcolony formation in strain MC58 depended on a functional copy of the pilE gene encoding the pilus subunit pilin, and was associated with twitching of cells. Nevertheless, unpiliated pilE mutants formed biofilms showing that attachment and accumulation...... PilX alleles was identified among genetically diverse meningococcal strains. PilX alleles differed in their propensity to support autoaggregation of cells in suspension, but not in their ability to support microcolony formation within biofilms in the continuous flow system....

  17. Galaxy formation and evolution

    Mo, Houjun; White, Simon

    2010-01-01

    The rapidly expanding field of galaxy formation lies at the interface between astronomy, particle physics, and cosmology. Covering diverse topics from these disciplines, all of which are needed to understand how galaxies form and evolve, this book is ideal for researchers entering the field. Individual chapters explore the evolution of the Universe as a whole and its particle and radiation content; linear and nonlinear growth of cosmic structure; processes affecting the gaseous and dark matter components of galaxies and their stellar populations; the formation of spiral and elliptical galaxies; central supermassive black holes and the activity associated with them; galaxy interactions; and the intergalactic medium. Emphasizing both observational and theoretical aspects, this book provides a coherent introduction for astronomers, cosmologists, and astroparticle physicists to the broad range of science underlying the formation and evolution of galaxies.

  18. Star Formation Rate Indicators

    Calzetti, Daniela

    2012-01-01

    What else can be said about star formation rate indicators that has not been said already many times over? The `coming of age' of large ground-based surveys and the unprecedented sensitivity, angular resolution and/or field-of-view of infrared and ultraviolet space missions have provided extensive, homogeneous data on both nearby and distant galaxies, which have been used to further our understanding of the strengths and pitfalls of many common star formation rate indicators. The synergy between these surveys has also enabled the calibration of indicators for use on scales that are comparable to those of star-forming regions, thus much smaller than an entire galaxy. These are being used to investigate star formation processes at the sub-galactic scale. I review progress in the field over the past decade or so.

  19. Prompt Planetesimal Formation beyond the Snow Line

    Armitage, Philip J.; Eisner, Josh A.; Simon, Jacob B.

    2016-09-01

    We develop a simple model to predict the radial distribution of planetesimal formation. The model is based on the observed growth of dust to millimeter-sized particles, which drift radially, pile-up, and form planetesimals where the stopping time and dust-to-gas ratio intersect the allowed region for streaming instability-induced gravitational collapse. Using an approximate analytic treatment, we first show that drifting particles define a track in metallicity–stopping time space whose only substantial dependence is on the disk’s angular momentum transport efficiency. Prompt planetesimal formation is feasible for high particle accretion rates (relative to the gas, {\\dot{M}}p/\\dot{M}≳ 3× {10}-2 for α ={10}-2), which could only be sustained for a limited period of time. If it is possible, it would lead to the deposition of a broad and massive belt of planetesimals with a sharp outer edge. Numerically including turbulent diffusion and vapor condensation processes, we find that a modest enhancement of solids near the snow line occurs for centimeter-sized particles, but that this is largely immaterial for planetesimal formation. We note that radial drift couples planetesimal formation across radii in the disk, and suggest that considerations of planetesimal formation favor a model in which the initial deposition of material for giant planet cores occurs well beyond the snow line.

  20. Laser filament-induced aerosol formation

    Saathoff, H.; Henin, S.; Stelmaszczyk, K.; Petrarca, M.; Delagrange, R.; Hao, Z.; Lüder, J.; Möhler, O.; Petit, Y.; Rohwetter, P.; Schnaiter, M.; Kasparian, J.; Leisner, T.; Wolf, J.-P.; Wöste, L.

    2013-05-01

    Using the aerosol and cloud simulation chamber AIDA, we investigated the laser filament induced particle formation in ambient air, humid synthetic air, humid nitrogen, argon-oxygen mixture, and pure argon in order to simulate the particle formation under realistic atmospheric conditions as well as to investigate the influence of typical gas-phase atmospheric constituents on the particle formation. Terawatt laser plasma filaments generated new particles in the size range 3 to 130 nm with particle production rates ranging from 1 × 107 to 5 × 109 cm-3 plasma s-1 for the given experimental conditions. In all cases the particle formation rates increased exponentially with the water content of the gas mixture. Furthermore, the presence of a few ppb of trace gases like SO2 and α-pinene clearly enhanced the particle yield by number, the latter also by mass. Our findings suggest that new particle formation is efficiently supported by oxidized species like acids generated by the photoionization of both major and minor components of the air, including N2, NH3, SO2 and organics.

  1. Mechanically loaded myotubes affect osteoclast formation.

    Juffer, Petra; Jaspers, Richard T; Klein-Nulend, Jenneke; Bakker, Astrid D

    2014-03-01

    In response to mechanical loading skeletal muscle produces numerous growth factors and cytokines that enter the circulation. We hypothesized that myotubes produce soluble factors that affect osteoclast formation and aimed to identify which osteoclastogenesis-modulating factors are differentially produced by mechanically stimulated myotubes. C2C12 myotubes were subjected to mechanical loading by cyclic strain for 1 h, and postincubated with or without cyclic strain for 24 h. The effect of cyclic strain on gene expression in myotubes was determined by PCR. Conditioned medium (CM) was collected from cultures of unloaded and loaded myotubes and from MLO-Y4 osteocytes. CM was added to mouse bone marrow cells containing osteoclast precursors, and after 6 days osteoclasts were counted. Compared to unconditioned medium, CM from unloaded osteocytes increased osteoclast formation, while CM from unloaded myotubes decreased osteoclast formation. Cyclic strain strongly enhanced IL-6 expression in myotubes. CM from cyclically strained myotubes increased osteoclast formation compared to CM from unloaded myotubes, but this effect did not occur in the presence of an IL-6 antibody. In conclusion, mechanically loaded myotubes secrete soluble factors, among others IL-6, which affect osteoclast formation. These results suggest that muscle could potentially affect bone homeostasis in vivo via production of growth factors and/or cytokines. PMID:24264813

  2. Laser filament-induced aerosol formation

    H. Saathoff

    2012-11-01

    Full Text Available Using the aerosol and cloud simulation chamber AIDA we investigated the laser filament induced particle formation in ambient air, humid synthetic air, humid nitrogen, argon-oxygen mixture, and pure argon in order to simulate the particle formation under realistic atmospheric conditions as well as to investigate the influence of typical gas-phase atmospheric constituents on the particle formation. Terawatt laser plasma filaments generated new particles in the size range 3 to 130 nm with particle production rates ranging from 1 × 107 to 5 × 109 cm−3 plasma s−1. In all cases the particle formation rates increased exponentially with the water content of the gas mixture. Furthermore, the presence of a few ppb of trace gases like SO2 and α-pinene clearly enhanced the particle yield by number, the latter also by mass. Our findings suggest that new particle formation is efficiently supported by acids generated by the photo-ionization of both major and minor components of the air, including N2, NH3, SO2 and organics.

  3. Laser filament-induced aerosol formation

    H. Saathoff

    2013-05-01

    Full Text Available Using the aerosol and cloud simulation chamber AIDA, we investigated the laser filament induced particle formation in ambient air, humid synthetic air, humid nitrogen, argon–oxygen mixture, and pure argon in order to simulate the particle formation under realistic atmospheric conditions as well as to investigate the influence of typical gas-phase atmospheric constituents on the particle formation. Terawatt laser plasma filaments generated new particles in the size range 3 to 130 nm with particle production rates ranging from 1 × 107 to 5 × 109 cm−3 plasma s−1 for the given experimental conditions. In all cases the particle formation rates increased exponentially with the water content of the gas mixture. Furthermore, the presence of a few ppb of trace gases like SO2 and α-pinene clearly enhanced the particle yield by number, the latter also by mass. Our findings suggest that new particle formation is efficiently supported by oxidized species like acids generated by the photoionization of both major and minor components of the air, including N2, NH3, SO2 and organics.

  4. Densities and Kinematic Viscosities for the Systems Benzene + Methyl Formate, Benzene + Ethyl Formate, Benzene + Propyl Formate, and Benzene + Butyl Formate

    Emmerling, Uwe; Rasmussen, Peter

    1998-01-01

    Densities and kinematic viscosities have been measured for the system benzene + methyl formate at 20°C and for the systems benzene + ethyl formate, benzene + propyl formate, and benzene + butyl formate from 20°C to 50°C. The results for the system benzene + methyl formate have been correlated using...... a Redlich-Kister type of expression with temperature-independent parameters and the data for the systems benzene + ethyl formate, benzene + propyl formate, and benzene + butyl formate with temperature-dependent parameters. The viscosities have furthermore been compared to values predicted by means...

  5. Metallic Nanomaterials for Sensitivity Enhancement of Fluorescence Detection

    Fang Xie; Goldys, Ewa M.

    2008-01-01

    Utrasensitive detection of trace analytes by fluorescence benefits for fluorescence amplifying substrates. We review here our recent work concerned with understanding of enhancement mechanisms and formation of three such substrates: silver fractals, silver coated gold nanoparticles deposited on glass and fluorescence enhancing gold colloids.

  6. Tea aroma formation

    Chi-Tang Ho

    2015-03-01

    Full Text Available Besides water, tea is one of the most popular beverages around the world. The chemical ingredients and biological activities of tea have been summarized recently. The current review summarizes tea aroma compounds and their formation in green, black, and oolong tea. The flavor of tea can be divided into two categories: taste (non-volatile compounds and aroma (volatile compounds. All of these aroma molecules are generated from carotenoids, lipids, glycosides, etc. precursors, and also from Maillard reaction. In the current review, we focus on the formation mechanism of main aromas during the tea manufacturing process.

  7. Exploring Opponent Formats

    Jensen, Mads Møller; Rasmussen, Majken; Grønbæk, Kaj

    2013-01-01

    The recent growth in development and research in computer-supported physical games has sprouted a wide variety of games merging qualities from both computer games and sports. Despite the increasing interest in this type of games, exploration of their specific game mechanics and the understanding ...... football-training platform, as well as games designed to explore the different opponent formats. The games are qualitatively evaluated to illuminate the qualities of and distinctions between different types of opponent formats, proposed by the framework terminology....

  8. Formats and data storage

    The currently used ENDF-6 format has a number of shortcomings that originate from the punch-card legacy. Some, such as redundancy, counting lines, too short MAT number and too many options could be resolved within the current format. The more critical issues, such as rigidity to extensions, limited accuracy due to fixed number of digits, difficulty of reading by humans, lack of native software support, and lack of integration with EXFOR and ENSDF libraries, would require such considerable efforts that migration to a new and modern format, offering additional advantages, is a more attractive option. Actually, such an option is even more justified by the existence of the well advanced General Nuclear Data (GND) format being developed by LLNL. This XML based framework is easily extensible, its numerical precision is not fixed, it is easier to edit, can store additional information (e.g. renormalized experimental data used in the evaluation), allows for storing various versions side by side (e.g. reconstructed data, group-wise data, alternative evaluations), it may include hyperlinks to documentation or another set of data (e.g. covariances). Two additional advantages are the possibility of using native Python support software and already available conversion (in both directions) to the binary HDF5 format which allows to organize, store, access, analyze, share, and preserve data huge in both size and complexity. The GND format comes with the processing software FUDGE, whose class structure mirrors the GND format. It provides for arbitrary alteration of the data, energy deposition/kermas, data checking, translation to different format (ENDF-6, HDF5, ENDL), grouping, resonance reconstruction, visualization and sampling from covariances. It is deemed advantageous to the Nuclear Data community to adopt this new system and develop interfaces to the currently used processing codes and retrieval systems to take full advantage of the evolving technology. Such modernization is

  9. The formation of stars

    Stahler, Steven W

    2008-01-01

    This book is a comprehensive treatment of star formation, one of the most active fields of modern astronomy. The reader is guided through the subject in a logically compelling manner. Starting from a general description of stars and interstellar clouds, the authors delineate the earliest phases of stellar evolution. They discuss formation activity not only in the Milky Way, but also in other galaxies, both now and in the remote past. Theory and observation are thoroughly integrated, with the aid of numerous figures and images. In summary, this volume is an invaluable resource, both as a text f

  10. Terrestrial planet formation

    Righter, K.; D. P. O’Brien

    2011-01-01

    Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (∼106 y), followed by planetesimals to embryos (lunar to Mars-sized objects; few × 106 y), and finally e...

  11. A role for phospholipase D3 in myotube formation.

    Mary Osisami

    Full Text Available Phospholipase D3 (PLD3 is a non-classical, poorly characterized member of the PLD superfamily of signaling enzymes. PLD3 is a type II glycoprotein associated with the endoplasmic reticulum, is expressed in a wide range of tissues and cells, and undergoes dramatic upregulation in neurons and muscle cells during differentiation. Using an in vitro skeletal muscle differentiation system, we define the ER-tethering mechanism and report that increased PLD3 expression enhances myotube formation, whereas a putatively dominant-negative PLD3 mutant isoform reduces myotube formation. ER stress, which also enhances myotube formation, is shown here to increase PLD3 expression levels. PLD3 protein was observed to localize to a restricted set of subcellular membrane sites in myotubes that may derive from or constitute a subdomain of the endoplasmic reticulum. These findings suggest that PLD3 plays a role in myogenesis during myotube formation, potentially in the events surrounding ER reorganization.

  12. Formation of protonium and positronium in atomic collisions

    Whitehead, R J

    2001-01-01

    method. Statistically accurate cross sections for protonium and antihydrogen formation have been obtained and the energy dependence of the process established. Antihydrogen formation from antiproton collisions with positronium in the presence of a laser has also been simulated with the CTMC method and the effects of laser polarisation, frequency and intensity studied. Enhancements of the antihydrogen formation cross section were observed and it is suggested that more sophisticated calculations should be undertaken. A minimum-norm method has been developed for solving the coupled integro-differential equations describing the scattering of positrons by one-electron targets in which the rearrangement channels for positronium formation have been explicitly included. The minimum-norm method, applied to this application for the first time in this thesis, is an enhancement of a previously reported least-squares method which has enabled the extension to a significantly larger basis consisting of up to 26 states on th...

  13. Current enhancement update

    Net current enhancement to levels in excess of the beam current has been observed in gases at pressures excess of 50 torr. We delineate the regimes where enhancement is observed. The experimental results fall into two very distinct classes; current enhancement at injection where the beam is only slightly displaced and current enhancement clearly associated with the high amplitude hose instability. A careful theoretical and experimental study of the diagnostics revealed no fundamental flaws although there are several complex and unlikely scenarios which could introduce fictitious current enhancement. Theoretical efforts indicate several mechanisms for generating enhancement but none of the theories can account for the detailed observations. 4 references, 4 figures

  14. Reference Citation Format

    2008-01-01

    <正>The format for citations in text and for bibliographic references follows the Publication Manual of the American Psychological Association(5thEd.,2001)and GB/T 7714-2005.The citation of printed word should be ordered in number as it appears in the text of the submitted

  15. Airship formation control

    Bicho, E.; Moreira, André; Diegues, Sérgio; Carvalheira, Manuel Pereira; Monteiro, Sérgio

    2006-01-01

    This paper addresses the problem underlying the control and coordination of multiple autonomous airships that must travel maintaining a desired geometric formation and simultaneously avoid collisions with moving or stationary obstacles. The control architecture is based on the attractor dynamics approach to behaviour generation. The airship physical model is presented and the mathematical background for the control architecture is explained. Simulations (with perturbations) ...

  16. Triggered Star Formation

    Palouš, Jan

    Berlin: Springer, 2014 - (Stamatellos, D.), s. 181-184. ( Astrophysics and Space Science Proceedings. 36). ISBN 978-3-319-03040-1. ISSN 1570-6591. [The Labyrinth of Star Formation. Crete (GR), 18.06.2012-22.06.2012] Institutional support: RVO:67985815 Keywords : interstellar gas layers * expanding shells * irregular galaxies Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  17. Syntactic Formats for Free

    Klin, Bartek; Sobocinski, Pawel

    2003-01-01

    A framework of Plotkin and Turi’s, originally aimed at providing an abstract notion of bi-simulation, is modified to cover other operational equivalences and preorders. Combined with bi-algebraic methods, it yields a technique for the derivation of syntactic formats for transition system...

  18. Exploring Formative Assessment Using Cultural Historical Activity Theory

    Mandy Asghar

    2013-01-01

    Formative assessment is a pedagogic practice that has been the subject of much research and debate, as to how it can be used most effectively to deliver enhanced student learning in the higher education setting. Often described as a complex concept it embraces activities that range from facilitating students understanding of assessment standards, to providing formative feedback on their work; from very informal opportunities of engaging in conversations, to the very formal process of submitti...

  19. A newly discovered xenobiotic metabolic pathway: Ethyl ester formation

    Chou, R.C.; Wyss, R.; Huselton, C.A.; Wiegand, U.W. (F. Hoffmann-La Roche Ltd., Basel (Switzerland))

    1991-01-01

    Formation of etretinate, ethyl ester of acitretin, can be confirmed in vitro and in vivo using acitretin as the substrate. Etretinate was identified by LC/MS. The in vitro incubation was performed using rat and human liver 12000 g supernatant, and the in vivo experiment was conducted in rats after oral dosing of acitretin. The ethyl ester formation was greatly enhanced by addition of or dosing with ethanol.

  20. Formation of aqueous-phase α-hydroxyhydroperoxides (α-HHP): potential atmospheric impacts

    Zhao, R.; A. K. Y. Lee; Soong, R; Simpson, A. J.; J. P. D. Abbatt

    2013-01-01

    The focus of this work is on quantifying the degree of the aqueous-phase formation of α-hydroxyhydroperoxides (α-HHPs) via reversible nucleophilic addition of H2O2 to aldehydes. Formation of this class of highly oxygenated organic hydroperoxides represents a poorly characterized aqueous-phase processing pathway that may lead to enhanced SOA formation and aerosol toxicity. Specifically, the equilibrium constants of α-HHP formation have been determi...

  1. Formation of aqueous-phase α-hydroxyhydroperoxides (α-HHP): potential atmospheric impacts

    Zhao, R.; A. K. Y. Lee; Soong, R; Simpson, A. J.; J. P. D. Abbatt

    2013-01-01

    The focus of this work is on quantifying the degree of the aqueous-phase formation of α-hydroxyhydroperoxides (α-HHPs) via reversible nucleophilic addition of H2O2 to aldehydes. Formation of this class of highly oxygenated organic hydroperoxides represents a poorly characterized aqueous-phase processing pathway that may lead to enhanced SOA formation and aerosol toxicity. Specifically, the equilibrium constants of α-HHP formation have been determined using proton nuclear-magnetic-resonance (1...

  2. IMPORTANCE OF MICROORGANISMS IN THE FORMATION OF COMPOUND COMPOST

    Belyuchenko I. S.

    2014-01-01

    Formation of the compound compost is due to com-pounds of mineral and organic colloids, creating new cycles biogens, enhancing the enzymatic activity of or-ganic matter, respiration of living organisms, the occur-rence of gaseous compounds, especially nitrogen, ex-panding ecological niches. Number of microbial com-munities evaluates the level transformation of organic matter, the activity life-support systems of living organ-isms. Introduction of complex compost to the soil en-hances of possi...

  3. Gas inflows, star formation and metallicity evolution in galaxy pairs

    Di Matteo, P; Montuori, M.; Lehnert, M. D.; Combes, F; Semelin, B.

    2011-01-01

    It has been known since many decades that galaxy interactions can induce star formation (hereafter SF) enhancements and that one of the driving mechanisms of this enhancement is related to gas inflows into the central galaxy regions, induced by asymmetries in the stellar component, like bars. In the last years many evidences have been accumulating, showing that interacting pairs have central gas-phase metallicities lower than those of field galaxies, by {\\sim} 0.2-0.3 dex on average. These di...

  4. Dynamic Aspects of Synapse Formation

    McAllister, A. Kimberley

    2007-01-01

    The mammalian central nervous system (CNS) requires the proper formation of exquisitely precise circuits to function correctly. These neuronal circuits are assembled during development by the formation of synaptic connections between thousands of differentiating neurons. Proper synapse formation during childhood provides the substrate for cognition while improper formation or function of these synapses leads to neurodevelopmental disorders, including mental retardation and autism. Recent work...

  5. Oxygen-enhanced combustion

    Baukal, Charles E

    2013-01-01

    Combustion technology has traditionally been dominated by air/fuel combustion. However, two developments have increased the significance of oxygen-enhanced combustion-new technologies that produce oxygen less expensively and the increased importance of environmental regulations. Advantages of oxygen-enhanced combustion include less pollutant emissions as well as increased energy efficiency and productivity. Oxygen-Enhanced Combustion, Second Edition compiles information about using oxygen to enhance industrial heating and melting processes. It integrates fundamental principles, applications, a

  6. Disposal in argillaceous formations

    A general description is made of clay as a geochemical medium, including a rapid review of the principal mineralogic data characterizing typical clay minerals, whereafter a description follows of the formation of geologic clay deposits. Two examples are used as illustration: the Boom clay formation at the Nuclear Center of Mol in Belgium and the marly clay layer at the Trisaia Nuclear Research Center in Italy. The principal physico-chemical and hydrogeologic properties of clays e.g. permeability and pore water composition are discussed in some detail due to their importance in assessing clay layers as host rock. Ion exchange of clays is reviewed with particular emphasis on the distribution coefficients, the diffusion coefficient and the migration parameters of radionuclides. Specific data relating to the Boom clay are commented in connection to the required conditioning techniques. The influence of heat on clay is shortly addressed and data are given of the heat transfer coefficients found in Belgium and Italy

  7. Moment formation in solids

    The problem of moment formation in metallic systems lies at the interface of localized and itinerant magnetism. The phenomena observed correspond to destruction rather than to formation of spin-correlations. They give rise to the progression from localized ground states through Kondo and mixed-valence behavior to itinerant magnetic or non-magnetic systems. Somewhere in the progression superconductivity can occur in the presence of f-moments. This conference presents information on the following topics: neuron inelastic scattering as a probe of moments in metallic systems; cyclotron resonance and relaxation of hot charge carriers; orbital effects in actinide systems; theory of elementary excitations in intermediate valence materials: phenomena involving magnetic moment suppresion; and superconducting ground state of a strongly interacting electron system: UBe13

  8. Emptiness Formation Probability

    Crawford, Nicholas; Ng, Stephen; Starr, Shannon

    2016-08-01

    We present rigorous upper and lower bounds on the emptiness formation probability for the ground state of a spin-1/2 Heisenberg XXZ quantum spin system. For a d-dimensional system we find a rate of decay of the order {exp(-c L^{d+1})} where L is the sidelength of the box in which we ask for the emptiness formation event to occur. In the {d=1} case this confirms previous predictions made in the integrable systems community, though our bounds do not achieve the precision predicted by Bethe ansatz calculations. On the other hand, our bounds in the case {d ≥ 2} are new. The main tools we use are reflection positivity and a rigorous path integral expansion, which is a variation on those previously introduced by Toth, Aizenman-Nachtergaele and Ueltschi.

  9. Pattern formation during vasculogenesis.

    Czirok, Andras; Little, Charles D

    2012-06-01

    Vasculogenesis, the assembly of the first vascular network, is an intriguing developmental process that yields the first functional organ system of the embryo. In addition to being a fundamental part of embryonic development, vasculogenic processes also have medical importance. To explain the organizational principles behind vascular patterning, we must understand how morphogenesis of tissue level structures can be controlled through cell behavior patterns that, in turn, are determined by biochemical signal transduction processes. Mathematical analyses and computer simulations can help conceptualize how to bridge organizational levels and thus help in evaluating hypotheses regarding the formation of vascular networks. Here, we discuss the ideas that have been proposed to explain the formation of the first vascular pattern: cell motility guided by extracellular matrix alignment (contact guidance), chemotaxis guided by paracrine and autocrine morphogens, and sprouting guided by cell-cell contacts. PMID:22692888

  10. Format( )MEDIC( )Input

    Foster, K.

    1994-09-01

    This document is a description of a computer program called Format( )MEDIC( )Input. The purpose of this program is to allow the user to quickly reformat wind velocity data in the Model Evaluation Database (MEDb) into a reasonable 'first cut' set of MEDIC input files (MEDIC.nml, StnLoc.Met, and Observ.Met). The user is cautioned that these resulting input files must be reviewed for correctness and completeness. This program will not format MEDb data into a Problem Station Library or Problem Metdata File. A description of how the program reformats the data is provided, along with a description of the required and optional user input and a description of the resulting output files. A description of the MEDb is not provided here but can be found in the RAS Division Model Evaluation Database Description document.

  11. Photochemical formation of intricarene.

    Stichnoth, Desiree; Kölle, Patrick; Kimbrough, Thomas J; Riedle, Eberhard; de Vivie-Riedle, Regina; Trauner, Dirk

    2014-01-01

    Sunlight is the ultimate driver of biosynthesis but photochemical steps late in biosynthetic pathways are very rare. They appear to play a role in the formation of certain furanocembranoids isolated from Caribbean corals. One of these compounds, intricarene, has been suspected to arise from an intramolecular 1,3-dipolar cycloaddition involving an oxidopyrylium. Here we show, by a combination of experiments and theory, that the oxidopyrylium forms under photochemical conditions and that its cycloaddition occurs via a triplet state. The formation of a complex by-product can be rationalized by another photochemical step that involves a conical intersection. Our work raises the question whether intricarene is biosynthesized in the natural habitat of the corals or is an artefact formed during workup. It also demonstrates that the determination of exact irradiation spectra, in combination with quantum chemical calculations, enables the rationalization of complex reaction pathways that involve multiple excited states. PMID:25470600

  12. Plasma formation in TBR

    In this work are presented and discussed results of the formation and equilibrium of the plasma current in TBR, a small tokamak, designed and contructed at the Instituto de Fisica of Universidade de Sao Paulo. The measured breakdown curves for H2, A and He are compared with the predictions of a simple model with reasonable agreement. The influence of stray magnetic fields in the plasma formation is investigated and conditions are chosen to facilitate the breakdown. The time profile of loop voltage and plasma current for shots with plasma equilibrium are shown. A comparison is made between experimental results and analytical-numerical model for tokamaks discharges with ohmic heating. Reasonable agreement is obtained when Z, effective atomic number, is assumed as a parameter. (Author)

  13. Formation of multiple networks

    Magnani, Matteo; Rossi, Luca

    2013-01-01

    While most research in Social Network Analysis has focused on single networks, the availability of complex on-line data about individuals and their mutual heterogenous connections has recently determined a renewed interest in multi-layer network analysis. To the best of our knowledge, in this paper...... we introduce the first network formation model for multiple networks. Network formation models are among the most popular tools in traditional network studies, because of both their practical and theoretical impact. However, existing models are not sufficient to describe the generation of multiple...... networks. Our model, motivated by an empirical analysis of real multi-layered network data, is a conservative extension of single-network models and emphasizes the additional level of complexity that we experience when we move from a single- to a more complete and realistic multi-network context....

  14. Frost formation with salt

    Guadarrama-Cetina, J.; Mongruel, A. (Anne); González-Viñas, W.; Beysens, D.A. (Daniel A.)

    2015-01-01

    The formation of frost in presence of salt (NaCl) crystal is experimentally investigated on a hydrophobic surface. It presents several remarkable features due to the interplay of salty-water saturation pressure evolution, initially lower than the saturation pressure of ice and water, and the percolating propagation of ice dendrites from defects throughout the supercooled water droplet pattern. In particular, it is remarkable that nucleation of supercooled water and/or ice is prevented around ...

  15. Formate-assisted pyrolysis

    DeSisto, William Joseph; Wheeler, Marshall Clayton; van Heiningen, Adriaan R. P.

    2015-03-17

    The present invention provides, among other thing, methods for creating significantly deoxygenated bio-oils form biomass including the steps of providing a feedstock, associating the feedstock with an alkali formate to form a treated feedstock, dewatering the treated feedstock, heating the dewatered treated feedstock to form a vapor product, and condensing the vapor product to form a pyrolysis oil, wherein the pyrolysis oil contains less than 30% oxygen by weight.

  16. Reference Citation Format

    2008-01-01

    <正>The format for citations in text and for bibliographic references follows the Publication Manual of the American Psychological Association(5thEd.,2001)and GB/T 7714-2005.The citation of printed word should be ordered in number as it appears in the text of the submitted article.For journal article1 Goodrum,A.A.,McCain,K.W.,&Lawrence,S.,et al.Scholarly publishing in the Internet age:

  17. Reference Citation Format

    2009-01-01

    <正>The format for citations in text and for bibliographic references follows the Publication Manual of the American Psychological Association(5thEd.,2001)and GB/T 7714-2005.The citation of printed word should be ordered in number as it appears in the text of the submitted article.For journal article1 Goodrum,A.A.,McCain,K.W.,&Lawrence,S.,et al.Scholarly publishing in the Internet

  18. Reference Citation Format

    2009-01-01

    <正>The format for citations in text and for bibliographic references follows the Publication Manual of the American Psychological Association(5thEd.,2001)and GB/T 7714-2005.The citation of printed word should be ordered in number as it appears in the text of the submitted article.For journal article1 Goodrum,A.A.,McCain,K.W.,&Lawrence,S.,et al.Scholarly publishing in the Internet age:

  19. Reference Citation Format

    2010-01-01

    <正>The format for citations in text and for bibliographic references follows the Publication Manual of the American Psychological Association(5thEd.,2001)and GB/T 7714-2005.The citation of printed word should be ordered in number as it appears in the text of the submitted article.For journal article1 Goodrum,A.A.,McCain,K.W.,&Lawrence,S.,et al.Scholarly publishing in the Internet

  20. Egg Formation in Lepidoptera

    William H. Telfer

    2009-01-01

    Reproductive biology in the Twentieth Century produced comprehensive descriptions of the mechanisms of egg formation in most of the major orders of insects. While many general principles of ovarian development and physiology emerged, every order turned out to have a set of its own special motifs. Discovery of the lepidopteran motifs is summarized in this essay. The emphasis is on developmental mechanisms, beginning with the early growth and differentiation of female germ cells and ending, aft...

  1. Modeling river delta formation

    Seybold, Hansjörg; Andrade, José S.; Herrmann, Hans J.

    2007-01-01

    A model to simulate the time evolution of river delta formation process is presented. It is based on the continuity equation for water and sediment flow and a phenomenological sedimentation/erosion law. Different delta types are reproduced by using different parameters and erosion rules. The structures of the calculated patterns are analyzed in space and time and compared with real data patterns. Furthermore, our model is capable of simulating the rich dynamics related to the switching of the...

  2. Galaxy Formation and Evolution

    Nagamine, Kentaro; Reddy, Naveen; Daddi, Emanuele; Sargent, Mark T.

    2016-07-01

    In this chapter, we discuss the current status of observational and computational studies on galaxy formation and evolution. In particular, a joint analysis of star-formation rates (SFRs), stellar masses, and metallicities of galaxies throughout cosmic time can shed light on the processes by which galaxies build up their stellar mass and enrich the environment with heavy elements. Comparison of such observations and the results of numerical simulations can give us insights on the physical importance of various feedback effects by supernovae and active galactic nuclei. In Sect. 1, we first discuss the primary methods used to deduce the SFRs, stellar masses, and (primarily) gas-phase metallicities in high-redshift galaxies. Then, we show how these quantities are related to each other and evolve with time. In Sect. 2, we further examine the distribution of SFRs in galaxies following the `Main Sequence' paradigm. We show how the so-called `starbursts' display higher specific SFRs and SF efficiencies by an order of magnitude. We use this to devise a simple description of the evolution of the star-forming galaxy population since z ˜3 that can successfully reproduce some of the observed statistics in the infrared (IR) wavelength. We also discuss the properties of molecular gas. In Sect. 3, we highlight some of the recent studies of high-redshift galaxy formation using cosmological hydrodynamic simulations. We discuss the physical properties of simulated galaxies such as luminosity function and escape fraction of ionizing photons, which are important statistics for reionization of the Universe. In particular the escape fraction of ionizing photons has large uncertainties, and studying gamma-ray bursts (which is the main topic of this conference) can also set observational constraints on this uncertain physical parameter as well as cosmic star formation rate density.

  3. Formation of Personal Identity

    Secher, Louise; Thulin, Cecilie; Miller, Juliet; Coulson, Maya

    2009-01-01

    Abstract The starting point for this project was our interest in how personal identity is formed, assuming that identity is acquired, not innate. Furthermore, we were interested in whether the formation of identity changes in relation to societal changes. We commenced by using theorist George Herbert Mead to specify the relationship between identity and society. We continued with Anthony Giddens’ theory regarding the construction of identity in a postmodern world. Phenomena demonstrated in...

  4. Layer Formation in Semiconvection

    Biello, Joseph A.

    2001-01-01

    Layer formation in a thermally destabilized fluid with stable density gradient has been observed in laboratory experiments and has been proposed as a mechanism for mixing molecular weight in late stages of stellar evolution in regions which are unstable to semiconvection. It is not yet known whether such layers can exist in a very low viscosity fluid: this work undertakes to address that question. Layering is simulated numerically both at high Prandtl number (relevant to the laboratory) in or...

  5. Formation of transient lamellipodia.

    Juliane Zimmermann

    Full Text Available Cell motility driven by actin polymerization is pivotal to the development and survival of organisms and individual cells. Motile cells plated on flat substrates form membrane protrusions called lamellipodia. The protrusions repeatedly appear and retract in all directions. If a lamellipodium is stabilized and lasts for some time, it can take over the lead and determine the direction of cell motion. Protrusions traveling along the cell perimeter have also been observed. Their initiation is in some situations the effect of the dynamics of the pathway linking plasma membrane receptors to actin filament nucleation, e.g. in chemotaxis. However, lamellipodia are also formed in many cells incessantly during motion with a constant state of the signaling pathways upstream from nucleation promoting factors (NPFs, or spontaneously in resting cells. These observations strongly suggest protrusion formation can also be a consequence of the dynamics downstream from NPFs, with signaling setting the dynamic regime but not initiating the formation of individual protrusions. A quantitative mechanism for this kind of lamellipodium dynamics has not been suggested yet. Here, we present a model exhibiting excitable actin network dynamics. Individual lamellipodia form due to random supercritical filament nucleation events amplified by autocatalytic branching. They last for about 30 seconds to many minutes and are terminated by filament bundling, severing and capping. We show the relevance of the model mechanism for experimentally observed protrusion dynamics by reproducing in very good approximation the repetitive protrusion formation measured by Burnette et al. with respect to the velocities of leading edge protrusion and retrograde flow, oscillation amplitudes, periods and shape, as well as the phase relation between protrusion and retrograde flow. Our modeling results agree with the mechanism of actin bundle formation during lamellipodium retraction suggested by

  6. Reference Citation Format

    2014-01-01

    <正>The format for citations in text and for bibliographic references follows GB/T 7714—2005.The citation should be ordered in number as it appears in the text of the submitted article.For journal article Sun,Y.,Li,B.,&Qu,J.F.Design and implementation of library intelligent IM reference robot.New Technology of Library and Information Service(in Chinese),

  7. Reference Citation Format

    2012-01-01

    <正>The format for citations in text and for bibliographic references follows GB/T 7714—2005.The citation should be ordered in number as it appears in the text of the submitted article.For journal article Sun,Y.,Li,B.,&Qu,J.F.Design and implementation of library intelligent IM reference robot.New Technology of Library and Information Service(in Chinese),2011,205:88–92.

  8. Unemployment and Household formation

    Ebrahim, Amina; Woolard, Ingrid; Leibbrandt, Murray

    2013-01-01

    In comparison to other continents, Africa has received little scholarly attention with regard to household composition. Household composition is endogenous to a variety of welfare issues and little is understood about the determinants of this composition. Understanding the household composition and formation decision may improve our understanding of how the unemployed gain access to resources and how household composition could provide a safety net to the unemployed. However, increasingly, mo...

  9. THE ALLIANCE FORMATION PROCESS

    Whipple, Judith M.; Frankel, Robert

    1998-01-01

    While interest in developing strategic alliances within the food system continues to increase, there remains considerable risk when firms adopt such a cooperative strategy. The risk is due in part to the lack of concrete guidelines that illustrate the steps or stages of alliance development and the important strategic and operational decisions required at each stage. The existence of such guidelines would facilitate alliance formation and enable managers and researchers to better understand a...

  10. Terrestrial planet formation.

    Righter, K; O'Brien, D P

    2011-11-29

    Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (~10(6) y), followed by planetesimals to embryos (lunar to Mars-sized objects; few 10(6) y), and finally embryos to planets (10(7)-10(8) y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids. PMID:21709256

  11. Mars brine formation experiment

    Moore, Jeffrey M.; Bullock, Mark A.; Stoker, Carol R.

    1992-01-01

    Evaporites, particularly carbonates, nitrates, and sulfates, may be major sinks of volatiles scavenged from the martian atmosphere. Mars is thought to have once had a denser, warmer atmosphere that permitted the presence of liquid surface water. The conversion of atmospheric CO2 into carbonate is hypothesized to have degraded the martian climate to its present state of a generally subfreezing, desiccated desert. The rate for such a conversion under martian conditions is poorly known, so the time scale of climate degradation by this process cannot be easily evaluated. If some models are correct, carbonate formation may have been fast at geological time scales. The experiments of Booth and Kieffer also imply fast (10(exp 6) - 10(exp 7) yr) removal of the missing CO2 inventory, estimated to be 1 - 5 bar, by means of carbonate formation. The timing of formation of many of the fluvial features observed on Mars is, in large part, dependent on when and how fast the atmosphere changed. A knowledge of the rate at which carbonates and nitrates formed is also essential for assessing the probability that life, or its chemical precursors, could have developed on Mars. No previous experiments have quantitatively evaluated the rate of solution for a suite of mobile anions and cations from unaltered minerals and atmospheric gases into liquid water under Mars-like conditions. Such experiments are the focus of this task.

  12. Cosmic Star Formation History

    Madau, Piero

    2014-01-01

    Over the last decade and a half, an avalanche of new data from multiwavelength imaging and spectroscopic surveys has revolutionized our view of galaxy formation and evolution. Making sense of it all and fitting it together into a coherent picture remains one of astronomy's great challenges. Here we review the range of complementary techniques and theoretical tools that are allowing astronomers to map the cosmic history of star formation, heavy element production, and reionization of the universe from the cosmic "dark ages" to the present epoch. A consistent picture is emerging from modern galaxy surveys, whereby the star formation rate density peaked about 3.5 Gyr after the Big Bang, at redshift 1.9, and declined exponentially at later times, with an e-folding timescale of 3.9 Gyr. Half of the stellar mass observed today was formed before redshift 1.3. Less than 1% of today's stars formed during the epoch of reionization, at redshift greater than 6. Under the simple assumption of a universal initial mass func...

  13. Formation of Lunar Swirls

    Bamford, R A; Cruz, F; Kellett, B J; Fonseca, R A; Silva, L O; Trines, R M G M; Halekas, J S; Kramer, G; Harnett, E; Cairns, R A; Bingham, R

    2015-01-01

    In this paper we show a plausible mechanism that could lead to the formation of the Dark Lanes in Lunar Swirls, and the electromagnetic shielding of the lunar surface that results in the preservation of the white colour of the lunar regolith. We present the results of a fully self-consistent 2 and 3 dimensional particle-in-cell simulations of mini-magnetospheres that form above the lunar surface and show that they are consistent with the formation of `lunar swirls' such as the archetypal formation Reiner Gamma. The simulations show how the microphysics of the deflection/shielding of plasma operates from a kinetic-scale cavity, and show that this interaction leads to a footprint with sharp features that could be the mechanism behind the generation of `dark lanes'. The physics of mini-magnetospheres is described and shown to be controlled by space-charge fields arising due to the magnetized electrons and unmagnetized ions. A comparison between model and observation is shown for a number of key plasma parameters...

  14. The Star Formation Camera

    Scowen, Paul A; Beasley, Matthew; Calzetti, Daniela; Desch, Steven; Fullerton, Alex; Gallagher, John; Lisman, Doug; Macenka, Steve; Malhotra, Sangeeta; McCaughrean, Mark; Nikzad, Shouleh; O'Connell, Robert; Oey, Sally; Padgett, Deborah; Rhoads, James; Roberge, Aki; Siegmund, Oswald; Shaklan, Stuart; Smith, Nathan; Stern, Daniel; Tumlinson, Jason; Windhorst, Rogier; Woodruff, Robert

    2009-01-01

    The Star Formation Camera (SFC) is a wide-field (~15'x19, >280 arcmin^2), high-resolution (18x18 mas pixels) UV/optical dichroic camera designed for the Theia 4-m space-borne space telescope concept. SFC will deliver diffraction-limited images at lambda > 300 nm in both a blue (190-517nm) and a red (517-1075nm) channel simultaneously. Our aim is to conduct a comprehensive and systematic study of the astrophysical processes and environments relevant for the births and life cycles of stars and their planetary systems, and to investigate and understand the range of environments, feedback mechanisms, and other factors that most affect the outcome of the star and planet formation process. This program addresses the origins and evolution of stars, galaxies, and cosmic structure and has direct relevance for the formation and survival of planetary systems like our Solar System and planets like Earth. We present the design and performance specifications resulting from the implementation study of the camera, conducted ...

  15. Exploiting droplet formation in microfluidic devices to create functional particles

    Nowak, Emilia; Simmons, Mark

    2014-11-01

    Microfluidic devices offer excellent capabilities for the formation of microstructured particles which have functional attributes e.g. in controlled delivery of pharmaceuticals, enhanced nutrition and flavours in food. In this work, a microfluidic device is employed to form microstructured particles in two steps: (i) by formation of single/double emulsions and (ii) solidification of the droplet by either gelation or solvent evaporation. Both may impart non-Newtonian properties to the component phases. The influence of phase flow rates (capillary number), surfactant type/concentration and the rheology of the component phases upon the particle formation and hydrodynamic behaviour are described. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

  16. Proplatelet formation in megakaryocytes is associated with endoplasmic reticulum stress.

    Morishima, Nobuhiro; Nakanishi, Keiko

    2016-07-01

    Although previous studies suggest that proplatelet formation in megakaryocytes involves caspase-3, the mechanism underlying the activation of caspase-3 is unknown. Here, we analyzed caspase activation in a human megakaryoblastic cell line, MEG-01, which forms proplatelets spontaneously. Specific activation of caspase-3 and caspase-4 was found in proplatelets. Consistent with previous observations of caspase-4 autoactivation in response to endoplasmic reticulum (ER) stress, several ER stress marker proteins were expressed during proplatelet formation. A pharmacological ER stressor enhanced platelet production via proplatelet formation, whereas inhibition of caspase-4 caused suppression. These results suggest that ER stress is a mechanism underlying the maturation of megakaryocytes. PMID:27296088

  17. Structure Formation in the Early Universe

    Miedema, P G

    2016-01-01

    The evolution of the perturbations in the energy density and the particle number density in a flat Friedmann-Lemaitre-Robertson-Walker universe in the radiation-dominated era and in the epoch after decoupling of matter and radiation is studied. For large-scale perturbations the outcome is in accordance with treatments in the literature. For small-scale perturbations the differences are conspicuous. Firstly, in the radiation-dominated era small-scale perturbations grew proportional to the square root of time. Secondly, perturbations in the Cold Dark Matter particle number density were, due to gravitation, coupled to perturbations in the total energy density. This implies that structure formation has commenced successfully only after decoupling of matter and radiation. Finally, after decoupling density perturbations evolved diabatically, i.e., they exchanged heat with their environment. This heat exchange may have enhanced the growth rate of its mass sufficiently to explain structure formation in the early univ...

  18. Molecular Cloud Turbulence and Star Formation

    Ballesteros-Paredes, J; MacLow, M M; Vázquez-Semadeni, E

    2006-01-01

    We review the properties of turbulent molecular clouds (MCs), focusing on the physical processes that influence star formation (SF). MC formation appears to occur during large-scale compression of the diffuse ISM driven by supernovae, magnetorotational instability, or gravitational instability in galactic disks of stars and gas. The compressions generate turbulence that can accelerate molecule production and produce the observed morphology. We then review the properties of MC turbulence, including density enhancements observed as clumps and cores, magnetic field structure, driving scales, the relation to observed scaling relations, and the interaction with gas thermodynamics. We argue that MC cores are dynamical, not quasistatic, objects with relatively short lifetimes not exceeding a few megayears. We review their morphology, magnetic fields, density and velocity profiles, and virial budget. Next, we discuss how MC turbulence controls SF. On global scales turbulence prevents monolithic collapse of the clouds...

  19. TIME-VARYING DYNAMICAL STAR FORMATION RATE

    We present numerical evidence of dynamic star formation in which the accreted stellar mass grows superlinearly with time, roughly as t 2. We perform simulations of star formation in self-gravitating hydrodynamic and magnetohydrodynamic turbulence that is continuously driven. By turning the self-gravity of the gas in the simulations on or off, we demonstrate that self-gravity is the dominant physical effect setting the mass accretion rate at early times before feedback effects take over, contrary to theories of turbulence-regulated star formation. We find that gravitational collapse steepens the density profile around stars, generating the power-law tail on what is otherwise a lognormal density probability distribution function. Furthermore, we find turbulent velocity profiles to flatten inside collapsing regions, altering the size-line width relation. This local flattening reflects enhancements of turbulent velocity on small scales, as verified by changes to the velocity power spectra. Our results indicate that gas self-gravity dynamically alters both density and velocity structures in clouds, giving rise to a time-varying star formation rate. We find that a substantial fraction of the gas that forms stars arrives via low-density flows, as opposed to accreting through high-density filaments

  20. Galaxy Interactions with FIRE: Mapping Star Formation

    Moreno, Jorge

    2016-01-01

    We utilize a suite of 75 simulations of galaxies in idealised major mergers (stellar mass ratio ~2.5:1), with a wide range of orbital parameters, to investigate the spatial extent of interaction-induced star formation. Two versions are used, one based on a Kennicult-like subgrid model (Gadget, Springel & Hernquist 2003); the other based on the new Feedback In Realistic Environments model (FIRE, Hopkins et al. 2014). Although the total star formation in galaxy encounters is generally elevated relative to isolated galaxies, we find that this elevation is a combination of intense enhancements within the central kpc and moderately suppressed activity at large galacto-centric radii. This effect appears to be stronger in the older Gadget model. Suppression is the disk is also found in the FIRE runs, but at larger scales. This is because tidal torques are weaker in the newer FIRE model, leading to a more extended nuclear starburt. Our predictions of the radial dependence of triggered star formation, and specifically the suppression of star formation beyond kpc-scales, will be testable with the next generation of integral-field spectroscopic surveys.

  1. Star-formation laws in extreme starbursts

    Garcia-Burillo, S; Alonso-Herrero, A

    2012-01-01

    The observational study of star-formation laws is paramount to disentangling the physical processes at work on local and global scales in galaxies. To this aim we have expanded the sample of extreme starbursts, represented by local LIRGs and ULIRGs, with high-quality data obtained in the 1-0 line of HCN. The analysis of the new data shows that the star-formation efficiency of the dense molecular gas, derived from the FIR/HCN luminosity ratio, is a factor 3-4 higher in extreme starbursts compared to normal galaxies. We find a duality in the Kennicutt-Schmidt laws that is enhanced if we account for the different conversion factor for HCN (alpha_HCN) in extreme starbursts and correct for the unobscured star-formation rate in normal galaxies. We find that it is possible to fit the observed differences in the FIR/HCN ratios between normal galaxies and LIRGs/ULIRGs with a common constant star-formation rate per free-fall time (SFR_ff) if we assume that HCN densities are ~1-2 orders of magnitude higher in LIRGs/ULIR...

  2. TIME-VARYING DYNAMICAL STAR FORMATION RATE

    Lee, Eve J.; Chang, Philip; Murray, Norman, E-mail: evelee@berkeley.edu [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, University of Toronto, Toronto, ON M5S 3H8 (Canada)

    2015-02-10

    We present numerical evidence of dynamic star formation in which the accreted stellar mass grows superlinearly with time, roughly as t {sup 2}. We perform simulations of star formation in self-gravitating hydrodynamic and magnetohydrodynamic turbulence that is continuously driven. By turning the self-gravity of the gas in the simulations on or off, we demonstrate that self-gravity is the dominant physical effect setting the mass accretion rate at early times before feedback effects take over, contrary to theories of turbulence-regulated star formation. We find that gravitational collapse steepens the density profile around stars, generating the power-law tail on what is otherwise a lognormal density probability distribution function. Furthermore, we find turbulent velocity profiles to flatten inside collapsing regions, altering the size-line width relation. This local flattening reflects enhancements of turbulent velocity on small scales, as verified by changes to the velocity power spectra. Our results indicate that gas self-gravity dynamically alters both density and velocity structures in clouds, giving rise to a time-varying star formation rate. We find that a substantial fraction of the gas that forms stars arrives via low-density flows, as opposed to accreting through high-density filaments.

  3. Divacancy formation by polyatomic ion implantation

    The production of the neutral divacancy absorption band (1.8 μm at 3000K) by the polyatomic series C+ (70 keV), CO+ (163 keV), CO2+ (256 keV), and by O1+ (85 keV), O2+ (170 keV), O3+ (255 keV) has been investigated. The oxygen series is emphasized because equal total energy and impurity deposition can be achieved simultaneously. For fluences significantly less than those required for amorphous layer formation, divacancy formation by 255 keV O3+ implantation at 3000K is approximately 1.5 times that for an equal atomic dose introduced by 85 keV O1+ implantation. Divacancy formation at 800K followed by heating to 3000K, is approximately 1.3 times that for an equivalent implantation at 3000K. An enhanced probability for divacancy formation with increasing initial defect density is suggested to explain the polyatomic and temperature effects. For polyatomic implantation the initial defect density is increased by simultaneous collisions within a cascade, while suppressed annealing allows accumulation of initial defects for low temperature implantation. Defect annealing for energy deposition near the crystalline-to-amorphous transition is especially important in determining the nature of the disorder. The results are compared with previous channeling-backscattering measurements of disorder produced by polyatomic implantation

  4. Arm & Interarm Star Formation in Spiral Galaxies

    Foyle, Kelly; Walter, Fabian; Leroy, Adam

    2010-01-01

    We investigate the relationship between spiral arms and star formation in the grand-design spirals NGC 5194 and NGC 628 and in the flocculent spiral NGC 6946. Filtered maps of near-IR (3.6 micron) emission allow us to identify "arm regions" that should correspond to regions of stellar mass density enhancements. The two grand-design spirals show a clear two-armed structure, while NGC 6946 is more complex. We examine these arm and interarm regions, looking at maps that trace recent star formation - far-ultraviolet (GALEX NGS) and 24 micron emission (Spitzer, SINGS) - and cold gas - CO (Heracles) and HI (Things). We find the star formation tracers and CO more concentrated in the spiral arms than the stellar 3.6 micron flux. If we define the spiral arms as the 25% highest pixels in the filtered 3.6 micron images, we find that the majority (60%) of star formation tracers occurs in the interarm regions; this result persists qualitatively even when considering the potential impact of finite data resolution and diffu...

  5. Evaluation of the intraspinal enhancement for medulloblastoma on MR imaging

    The purpose of this study was to analyze the enhancement pattern of the spinal cord for patients with medulloblastoma, and to correlate the enhancement pattern with cerebrospinal fluid (CSF) tumor seeding. We retrospectively reviewed 84 MR images, including the initial and follow-up studies after chemotherapy or radiation therapy, of 25 patients with medulloblastoma who were aged from 2 to 13 years. We analyzed the spinal leptomeningeal enhancement pattern on the MR images. The leptomeningeal enhancement patterns were categorized into three types: Type, I, fine or discontinuous linear enhancement, and type II, continuous linear or nodular enhancement, and type III, intradural mass formation. We correlated the enhancement pattern on MRI with the results of CSF cytology at the initial and follow-up examinations after treatment. Of total 25 patients, type I enhancement was observed for 14 patients. Twelve patients were negative on the initial CSF cytology and 2 patients were positive. On the follow-up MR studies, 14 patients showed no change or only a slight decrease of enhancement, and all were negative on the follow-up CSF cytology. Type II enhancement patterns were observed in seven patients, and all of them were positive on the initial CSF cytology. On follow-up MR study, one patient revealed an increased enhancement with the positive result on the follow-up CSF cytology, and six patients had decreased enhancement on the follow-up MR studies with negative conversion on the follow-up CSF cytology. Type III enhancement patterns were observed in four patients and all of them were positive on the initial CSF cytology. All four patients with tradural mass formations revealed progression of the lesions on follow-up MR studies, and all of them were positive on the follow-up CSF cytology. Type II and III enhancement patterns always represented CSF seeding and a type I enhancement pattern had a low probability of metastasis

  6. Evaluation of the intraspinal enhancement for medulloblastoma on MR imaging

    Kim, Hwa Young; Kim, In One; Kim, Woo Sun; Cheon, Jung Eun; Yeon, Kyung Mo [Seoul National Univ., Seoul (Korea, Republic of)

    2004-10-15

    The purpose of this study was to analyze the enhancement pattern of the spinal cord for patients with medulloblastoma, and to correlate the enhancement pattern with cerebrospinal fluid (CSF) tumor seeding. We retrospectively reviewed 84 MR images, including the initial and follow-up studies after chemotherapy or radiation therapy, of 25 patients with medulloblastoma who were aged from 2 to 13 years. We analyzed the spinal leptomeningeal enhancement pattern on the MR images. The leptomeningeal enhancement patterns were categorized into three types: Type, I, fine or discontinuous linear enhancement, and type II, continuous linear or nodular enhancement, and type III, intradural mass formation. We correlated the enhancement pattern on MRI with the results of CSF cytology at the initial and follow-up examinations after treatment. Of total 25 patients, type I enhancement was observed for 14 patients. Twelve patients were negative on the initial CSF cytology and 2 patients were positive. On the follow-up MR studies, 14 patients showed no change or only a slight decrease of enhancement, and all were negative on the follow-up CSF cytology. Type II enhancement patterns were observed in seven patients, and all of them were positive on the initial CSF cytology. On follow-up MR study, one patient revealed an increased enhancement with the positive result on the follow-up CSF cytology, and six patients had decreased enhancement on the follow-up MR studies with negative conversion on the follow-up CSF cytology. Type III enhancement patterns were observed in four patients and all of them were positive on the initial CSF cytology. All four patients with tradural mass formations revealed progression of the lesions on follow-up MR studies, and all of them were positive on the follow-up CSF cytology. Type II and III enhancement patterns always represented CSF seeding and a type I enhancement pattern had a low probability of metastasis.

  7. Formation and collapse of internal transport barrier

    A theoretical model of internal transport barrier (ITB) is developed. The transport model based on the self-sustained turbulence theory of the current-diffusive ballooning mode is extended to include the effects of ExB rotation shear. Delayed formation of ITB is observed in transport simulations. The influence of finite gyroradius is also discussed. Simulation of the current ramp-up experiment successfully described the radial profile of density, temperature and safety factor. A model of ITB collapse due to magnetic braiding is proposed. Sudden enhancement of transport triggered by overlaping of magnetic islands terminates ITB. The possibility of destabilizing global low-n modes is also discussed. (author)

  8. The Impact of an Alternative Professional Development Model on Teacher Practices in Formative Assessment and Student Learning

    Robinson, Jack; Myran, Steve; Strauss, Richard; Reed, William

    2014-01-01

    Among contemporary means of enhancing student learning, formative assessment is perhaps one of the most important and effective. While formative assessment ideas and practices have been shown to have a proven record enhancing student learning, these practices are slow to be fully integrated into teachers' day-to-day classroom practices. This…

  9. Equivalence Class Formation in a Trace Stimulus Pairing Two-Response Format: Effects of Response Labels and Prior Programmed Transitivity Induction

    Fields, Lanny; Doran, Erica; Marroquin, Michael

    2009-01-01

    Three experiments identified factors that did and did not enhance the formation of two-node four-member equivalence classes when training and testing were conducted with trials presented in a trace stimulus pairing two-response (SP2R) format. All trials contained two separately presented stimuli. Half of the trials, called within-class trials,…

  10. Smart Image Enhancement Process

    Jobson, Daniel J. (Inventor); Rahman, Zia-ur (Inventor); Woodell, Glenn A. (Inventor)

    2012-01-01

    Contrast and lightness measures are used to first classify the image as being one of non-turbid and turbid. If turbid, the original image is enhanced to generate a first enhanced image. If non-turbid, the original image is classified in terms of a merged contrast/lightness score based on the contrast and lightness measures. The non-turbid image is enhanced to generate a second enhanced image when a poor contrast/lightness score is associated therewith. When the second enhanced image has a poor contrast/lightness score associated therewith, this image is enhanced to generate a third enhanced image. A sharpness measure is computed for one image that is selected from (i) the non-turbid image, (ii) the first enhanced image, (iii) the second enhanced image when a good contrast/lightness score is associated therewith, and (iv) the third enhanced image. If the selected image is not-sharp, it is sharpened to generate a sharpened image. The final image is selected from the selected image and the sharpened image.

  11. Reference Citation Format

    2008-01-01

    <正>The format for citations in text and for bibliographic references follows the Publication Manual of the American Psychological Association(5th Ed.,2001)and GB/T 7714-2005.The citation of printed word should be ordered in number as it appears in the text of the submitted article.For journal article1 Goodrum,A.A.,McCain,K.W.,&Lawrence,S.,et al.Scholarly publishing in the Internet age:A citation analysis of computer science literature.Information Processing and Management,2001,37:661-675.

  12. Reference Citation Format

    2011-01-01

    <正>The format for citations in text and for bibliographic references follows the Publication Manual of the American Psychological Association(5thEd.,2001)and GB/T 7714-2005.The citation of printed word should be ordered in number as it appears in the text of the submitted article.For journal article1 Goodrum,A.A.,McCain,K.W.,&Lawrence,S.,et al.Scholarly publishing in the Internet age:A citation analysis of computer science literature.Information Processing and Manage-

  13. Modeling river delta formation

    Seybold, Hansjörg; Herrmann, Hans J

    2007-01-01

    A new model to simulate the time evolution of river delta formation process is presented. It is based on the continuity equation for water and sediment flow and a phenomenological sedimentation/ erosion law. Different delta types are reproduced using different parameters and erosion rules. The structures of the calculated patterns are analyzed in space and time and compared with real data patterns. Furthermore our model is capable to simulate the rich dynamics related to the switching of the mouth of the river delta. The simulation results are then compared with geological records for the Mississippi river.

  14. Modeling river delta formation.

    Seybold, Hansjörg; Andrade, José S; Herrmann, Hans J

    2007-10-23

    A model to simulate the time evolution of river delta formation process is presented. It is based on the continuity equation for water and sediment flow and a phenomenological sedimentation/erosion law. Different delta types are reproduced by using different parameters and erosion rules. The structures of the calculated patterns are analyzed in space and time and compared with real data patterns. Furthermore, our model is capable of simulating the rich dynamics related to the switching of the mouth of the river delta. The simulation results are then compared with geological records for the Mississippi River. PMID:17940031

  15. Symbol Formation Reconsidered

    Wagoner, Brady

    2013-01-01

    begins with a brief outline and contextualization of the book as well as of the articles that this special issue comprises. The first two articles were written by contributors who were part of the Werner era at Clark University. They explore the key concepts of the organismic and development, and situate......Werner and Kaplan’s Symbol formation was published 50 years ago but its insights have yet to be adequately explored by psychology and other social sciences. This special issue aims to revisit this seminal work in search of concepts to work on key issues facing us today. This introductory article...

  16. The Star Formation Camera

    Scowen, Paul A.; Jansen, Rolf; Beasley, Matthew; Calzetti, Daniela; Desch, Steven; Fullerton, Alex; Gallagher, John; Lisman, Doug; Macenka, Steve; Malhotra, Sangeeta; McCaughrean, Mark; Nikzad, Shouleh; O'Connell, Robert; Oey, Sally; Padgett, Deborah

    2009-01-01

    The Star Formation Camera (SFC) is a wide-field (~15'x19, >280 arcmin^2), high-resolution (18x18 mas pixels) UV/optical dichroic camera designed for the Theia 4-m space-borne space telescope concept. SFC will deliver diffraction-limited images at lambda > 300 nm in both a blue (190-517nm) and a red (517-1075nm) channel simultaneously. Our aim is to conduct a comprehensive and systematic study of the astrophysical processes and environments relevant for the births and life cycles of stars and ...

  17. Reference Citation Format

    2010-01-01

    <正>The format for citations in text and for bibliographic references follows the Publication Manual of the American Psychological Association(5thEd.,2001)and GB/T 7714-2005.The citation of printed word should be ordered in number as it appears in the text of the submitted article.For journal article1 Goodrum,A.A.,McCain,K.W.,&Lawrence,S.,et al.Scholarly publishing in the Internet age:A citation analysis of computer science literature.Information Processing and Management,2001,37:661-675.2 Fernandez,M.,Kadiyska,Y.,&Suciu,D.,et al.SilkRoute:A framework for publishing

  18. Reference Citation Format

    2011-01-01

    <正>The format for citations in text and for bibliographic references follows the Publication Manual of the American Psychological Association(5thEd.,2001)and GB/T 7714-2005.The citation of printed word should be ordered in number as it appears in the text of the submitted article.For journal article1 Goodrum,A.A.,McCain,K.W.,&Lawrence,S.,et al.Scholarly publishing in the Internet age:A citation analysis of computer science literature.Information Processing and Management,2001,37:661-675.2 Fernandez.M

  19. Enhanced Reporting of Mars Exploration Rover Telemetry

    Maimone, Mark W.; Biesiadecki, Jeffrey J.; Liebersbach, Robert T.; Carsten, Joseph L.; Leger, Chris

    2008-01-01

    Mars Exploration Rover Enhanced Telemetry Extraction and Reporting System (METERS) is software that generates a human-readable representation of the state of the mobility and arm-related systems of the Mars Exploration Rover (MER) vehicles on each Martian solar day (sol). Data are received from the MER spacecraft in multiple streams having various formats including text messages, sparsely-sampled engineering quantities, images, and individual motor-command histories.

  20. Microbial Enhanced Oil Recovery - Advanced Reservoir Simulation

    Nielsen, Sidsel Marie; Shapiro, Alexander; Stenby, Erling Halfdan; Michelsen, Michael Locht

    2010-01-01

    In this project, a generic model has been set up to include the two main mechanisms in the microbial enhanced oil recovery (MEOR) process; reduction of the interfacial tension (IFT) due to surfactant production, and microscopic fluid diversion as a part of the overall fluid diversion mechanism due to formation of biofilm. The construction of a one-dimensional simulator enables us to investigate how the different mechanisms and the combination of these influence the displacement processes, the...

  1. Using Formative Assessment and Metacognition to Improve Student Achievement

    Hudesman, John; Crosby, Sara; Flugman, Bert; Issac, Sharlene; Everson, Howard; Clay, Dorie B.

    2013-01-01

    This paper describes a multistep Enhanced Formative Assessment Program (EFAP) that features a Self-Regulated Learning (SRL) component. The program, which teaches students to become more effective learners, has been applied in a wide range of academic disciplines. In this paper we report on how the EFAP-SRL model can be applied to the area of…

  2. Star Formation in Irregular Galaxies.

    Hunter, Deidre; Wolff, Sidney

    1985-01-01

    Examines mechanisms of how stars are formed in irregular galaxies. Formation in giant irregular galaxies, formation in dwarf irregular galaxies, and comparisons with larger star-forming regions found in spiral galaxies are considered separately. (JN)

  3. Standard exercise report format (SERF)

    This talk summarizes the reasons for the development of draft SERF the Standard Exercise Report Format used for reporting the results of emergency preparedness exercises, and gives a summary of the format and rational behind it

  4. The Planet Formation Imager

    Kraus, S.; Buscher, D. F.; Monnier, J. D.; PFI Science, the; Technical Working Group

    2014-04-01

    Among the most fascinating and hotly-debated areas in contemporary astrophysics are the means by which planetary systems are assembled from the large rotating disks of gas and dust which attend a stellar birth. Although important work is being done both in theory and observation, a full understanding of the physics of planet formation can only be achieved by opening observational windows able to directly witness the process in action. The key requirement is then to probe planet-forming systems at the natural spatial scales over which material is being assembled. By definition, this is the so-called Hill Sphere which delineates the region of influence of a gravitating body within its surrounding environment. The Planet Formation Imager project has crystallized around this challenging goal: to deliver resolved images of Hill-Sphere-sized structures within candidate planet-hosting disks in the nearest star-forming regions. In this contribution we outline the primary science case of PFI and discuss how PFI could significantly advance our understanding of the architecture and potential habitability of planetary systems. We present radiation-hydrodynamics simulations from which we derive preliminary specifications that guide the design of the facility. Finally, we give an overview about the interferometric and non-interferometric technologies that we are investigating in order to meet the specifications.

  5. Formation of planetary systems

    It seemed appropriate to devote the 1980 School to the origin of the solar system and more particularly to the formation of planetary systems (dynamic accretion processes, small bodies, planetary rings, etc...) and to the physics and chemistry of planetary interiors, surface and atmospheres (physical and chemical constraints associated with their formation). This Summer School enabled both young researchers and hard-nosed scientists, gathered together in idyllic surroundings, to hold numerous discussions, to lay the foundations for future cooperation, to acquire an excellent basic understanding, and to make many useful contacts. This volume reflects the lectures and presentations that were delivered in this Summer School setting. It is aimed at both advanced students and research workers wishing to specialize in planetology. Every effort has been made to give an overview of the basic knowledge required in order to gain a better understanding of the origin of the solar system. Each article has been revised by one or two referees whom I would like to thank for their assistance. Between the end of the School in August 1980 and the publication of this volume in 1982, the Voyager probes have returned a wealth of useful information. Some preliminary results have been included for completeness

  6. Compact toroid formation experiments

    We present the design and experimental performance of a compact toroid (CT) formation experiment. The device has co-axial electrode diameters of 0.9 m (inner) and 1.25 m (outer), and an electrode length of ∼ 1.2 m, including an expansion/drift section. The CT is formed by a 0.1--0.2 Tesla initial radial magnetic field embedded co-axial puff gas discharge. The gas puff is injected with an array of 60 pulsed solenoid driven fast valves. The formation discharge is driven by a 108 microfarad, 40 to 100 KV, 86 to 540 kilojoule 2 to 5 megamp capacitor discharge with ∼ 20 nanohenry initial total discharge inductance. The hardware includes transmission line connections for a Shiva Star (1300 microfarad, up to 120 KV, 0.4 megajoule) capacitor bank driven acceleration discharge. Experimental measurements include current, voltage; azimuthal, radial and axial magnetic field at numerous location; fast photography, optical spectroscopy; microwave, CO2 laser, and He-Ne laser interferometry. Auxiliary experiments include Penning ionization gauge, pressure probe, and breakdown gas trigger diagnostics of gas injection, and Hall probe measurements of magnetic field injection

  7. Thiol isomerases in thrombus formation

    Furie, Bruce; Flaumenhaft, Robert

    2014-01-01

    Protein disulfide isomerase, ERp5 and ERp57, among perhaps other thiol isomerases, are important for the initiation of thrombus formation. Using the laser injury thrombosis model in mice to induce in vivo arterial thrombus formation, it was shown that thrombus formation is associated with PDI secretion by platelets, that inhibition of PDI blocked platelet thrombus formation and fibrin generation, and that endothelial cell activation leads to PDI secretion. Similar results using this and other...

  8. [Medical image enhancement: Sharpening].

    Kats, L; Vered, M

    2015-04-01

    Most digital imaging systems provide opportunities for image enhancement operations. These are applied to improve the original image and to make the image more appealing visually. One possible means of enhancing digital radiographic image is sharpening. The purpose of sharpening filters is to improve image quality by removing noise or edge enhancement. Sharpening filters may make the radiographic images subjectively more appealing. But during this process, important radiographic features may disappear while artifacts that simulate pathological process might be generated. Therefore, it is of utmost importance for dentists to be familiar with and aware of the use of image enhancement operations, provided by medical digital imaging programs. PMID:26255429

  9. Enhancing human capacities

    Savulescu, Julian; Kahane, Guy

    2011-01-01

    Enhancing Human Capacities is the first to review the very latest scientific developments in human enhancement. It is unique in its examination of the ethical and policy implications of these technologies from a broad range of perspectives. Presents a rich range of perspectives on enhancement from world leading ethicists and scientists from Europe and North America The most comprehensive volume yet on the science and ethics of human enhancement Unique in providing a detailed overview of current and expected scientific advances in this area Discusses both general conceptual and ethical issues

  10. Pore Scale Dynamics of Microemulsion Formation.

    Unsal, Evren; Broens, Marc; Armstrong, Ryan T

    2016-07-19

    Experiments in various porous media have shown that multiple parameters come into play when an oleic phase is displaced by an aqueous solution of surfactant. In general, the displacement efficiency is improved when the fluids become quasi-miscible. Understanding the phase behavior oil/water/surfactant systems is important because microemulsion has the ability to generate ultralow interfacial tension (microemulsion formation and the resulting properties under equilibrium conditions. However, the majority of applications where microemulsion is present also involve flow, which has received relatively less attention. It is commonly assumed that the characteristics of an oil/water/surfactant system under flowing conditions are identical to the one under equilibrium conditions. Here, we show that this is not necessarily the case. We studied the equilibrium phase behavior of a model system consisting of n-decane and an aqueous solution of olefin sulfonate surfactant, which has practical applications for enhanced oil recovery. The salt content of the aqueous solution was varied to provide a range of different microemulsion compositions and oil-water interfacial tensions. We then performed microfluidic flow experiments to study the dynamic in situ formation of microemulsion by coinjecting bulk fluids of n-decane and surfactant solution into a T-junction capillary geometry. A solvatochromatic fluorescent dye was used to obtain spatially resolved compositional information. In this way, we visualized the microemulsion formation and the flow of it along with the excess phases. A complex interaction between the flow patterns and the microemulsion properties was observed. The formation of microemulsion influenced the flow regimes, and the flow regimes affected the characteristics of the microemulsion formation. In particular, at low flow rates, slug flow was observed, which had profound consequences on the pore scale mixing behavior and resulting microemulsion properties. PMID

  11. Star Formation Across the W3 Complex

    Román-Zúñiga, Carlos G.; Ybarra, Jason E.; Megías, Guillermo D.; Tapia, Mauricio; Lada, Elizabeth A.; Alves, Joáo F.

    2015-09-01

    We present a multi-wavelength analysis of the history of star formation in the W3 complex. Using deep, near-infrared ground-based images combined with images obtained with Spitzer and Chandra observatories, we identified and classified young embedded sources. We identified the principal clusters in the complex and determined their structure and extension. We constructed extinction-limited samples for five principal clusters and constructed K-band luminosity functions that we compare with those of artificial clusters with varying ages. This analysis provided mean ages and possible age spreads for the clusters. We found that IC 1795, the centermost cluster of the complex, still hosts a large fraction of young sources with circumstellar disks. This indicates that star formation was active in IC 1795 as recently as 2 Myr ago, simultaneous to the star-forming activity in the flanking embedded clusters, W3-Main and W3(OH). A comparison with carbon monoxide emission maps indicates strong velocity gradients in the gas clumps hosting W3-Main and W3(OH) and shows small receding clumps of gas at IC 1795, suggestive of rapid gas removal (faster than the T Tauri timescale) in the cluster-forming regions. We discuss one possible scenario for the progression of cluster formation in the W3 complex. We propose that early processes of gas collapse in the main structure of the complex could have defined the progression of cluster formation across the complex with relatively small age differences from one group to another. However, triggering effects could act as catalysts for enhanced efficiency of formation at a local level, in agreement with previous studies.

  12. Formative E-Assessment in Plenary Lectures

    Rune Johan Krumsvik

    2012-03-01

    Full Text Available Little is known about how subjective and objective learning outcomes in plenary lectures are related in the Quality Framework of Higher Education and how they are influenced by formative e-assessment. Given the increasing focus on digitalisation and formative assessment in higher education and the increasing diversity among university students, questions relating to these topics should also be explored within plenary lectures. These lectures constitute the most formal, defined and “bounded” educational practice at universities and it is important to study the question of whether the relationship between student diversity, pedagogy and technology can re-define some of the pedagogical underpinnings that are historically associated with lecturer-centred pedagogy. This paper aims to identify: (1 factors that influence the relationship between intended and subjective learning outcomes in plenary lectures; and (2 how formative e-assessment may improve moments of contingency by increasing the consistency between intended and subjective learning outcomes. The results of this study show that audience response systems (ARS can enhance formative e-assessment in plenary lectures and reduce the discrepancy between the intended learning outcome and the subjective learning outcome in such lectures with several hundred students. The implications of the current paper are twofold: first, a better understanding of similarities and dissimilarities in students’ learning processes in plenary lectures and how these processes may be affected by formative e-assessment has implications for the planning and implementation of teaching and learning in higher education. Second, this has implications for how we can reduce the discrepancy between the intended, subjective and objective learning outcomes in plenary lectures.

  13. Social Network Formation with Consent

    Gilles, R.P.; Sarangi, S.

    2004-01-01

    We investigate the equilibria of game theoretic models of network formation that are based on individual actions only.Our approach is grounded in three simple and realistic principles: (1) Link formation should be a binary process of consent.(2) Link formation should be costly.(3) The class of netwo

  14. Formative Assessment: Simply, No Additives

    Roskos, Kathleen; Neuman, Susan B.

    2012-01-01

    Among the types of assessment the closest to daily reading instruction is formative assessment. In contrast to summative assessment, which occurs after instruction, formative assessment involves forming judgments frequently in the flow of instruction. Key features of formative assessment include identifying gaps between where students are and…

  15. Reservoir characterization of the Smackover Formation in southwest Alabama

    Kopaska-Merkel, D.C.; Hall, D.R.; Mann, S.D.; Tew, B.H.

    1993-02-01

    The Upper Jurassic Smackover Formation is found in an arcuate belt in the subsurface from south Texas to panhandle Florida. The Smackover is the most prolific hydrocarbon-producing formation in Alabama and is an important hydrocarbon reservoir from Florida to Texas. In this report Smackover hydrocarbon reservoirs in southwest Alabama are described. Also, the nine enhanced- and improved-recovery projects that have been undertaken in the Smackover of Alabama are evaluated. The report concludes with recommendations about potential future enhanced- and improved-recovery projects in Smackover reservoirs in Alabama and an estimate of the potential volume of liquid hydrocarbons recoverable by enhanced- and improved-recovery methods from the Smackover of Alabama.

  16. NANOCOMPOSITE COATINGS WITH ENHANCED HARDNESS

    J. Musil

    2005-01-01

    The article reviews the present state of the art in the magnetron sputtering of hart and superhard nanocomposite coatings. It is shown that there are (1) two groups of hard and superhard nanocomposites: (i) nc-MN/hard phase and (ii) nc-MN/soft phase, (2) three possible origins of the enhanced hardness: (i) dislocation-dominated plastic deformation, (ii) cohesive forces between atoms and (iii) nanostructure of materials, and (3) huge differences in the microstructure of single- and two-phase films. A main attention is devoted to the formation of nanocrystalline and/or X-ray amorphous films. Such films are created in a vicinity of transitions between (i)crystalline and amorphous phases, (ii) two crystalline phases of different chemical composition or (iii) two different preferred orientations of grains of the sane material from which the coating is composed. The existence of the last transition makes it possible to explain the enhanced hardness in single-phase films. The thermal stability and oxidation resistance of hard nanocomposite films is also shortly discussed.

  17. FOCUS ON FORMATIVE FEEDBACKCOMMUNICATION AND SELF-REGULATED LEARNING – A STUDY IN COMPULSORY SCHOOLS

    Kirkegaard, Preben Olund

    2016-01-01

    This study addresses the conceptual challenge of providing students in compulsory schools with good quality formative feedback to enhance self-regulated learning in social interactions. Resent educational research indicates that social communicative interactions in the classroom, with a focus on...... formative feedback, hold the potential to enhance students learning. Self-regulated learning is highly pertinent and can be seen as one of the most import skills for the 21st century learner. We argue that formative feedbackcommunication in interactions is crucial for students to develop self......-regulating skills and that feedback is not only something the teacher gives to the student. We refer to this as formative Feedbackcommunication. As a basis for exploring identifying and discussing relevant aspects of formative Feedbackcommunication to enhance student self-regulating learning skills we analyze...

  18. Dislocation Formation in Alloys

    Minami, Akihiko; Onuki, Akira

    2006-05-01

    An interaction between dislocations and phase transitions is studied by a phase field model both in two and three dimensional systems. Our theory is a simple extension of the traditional linear elastic theory, and the elastic energy is a periodic function of local strains which is reflecting the periodicity of crystals. We find that the dislocations are spontaneously formed by quenching. Dislocations are formed from the interface of binary alloys, and slips are preferentially gliding into the soft metals. In three dimensional systems, formation of dislocations under applied strain is studied in two phase state. We find that the dislocation loops are created from the surface of hard metals. We also studied the phase separation above the coexisting temperature which is called as the Cottrell atmosphere. Clouds of metals cannot catch up with the motion of dislocations at highly strained state.

  19. DUST FORMATION IN MACRONOVAE

    We examine dust formation in macronovae (as known as kilonovae), which are the bright ejecta of neutron star binary mergers and one of the leading sites of r-process nucleosynthesis. In light of information about the first macronova candidate associated with GRB 130603B, we find that dust grains of r-process elements have difficulty forming because of the low number density of the r-process atoms, while carbon or elements lighter than iron can condense into dust if they are abundant. Dust grains absorb emission from ejecta with an opacity even greater than that of the r-process elements, and re-emit photons at infrared wavelengths. Such dust emission can potentially account for macronovae without r-process nucleosynthesis as an alternative model. This dust scenario predicts a spectrum with fewer features than the r-process model and day-scale optical-to-ultraviolet emission

  20. Standardizing exchange formats

    An international network of co-operating data centres is described who maintain identical data bases which are simultaneously updated by an agreed data exchange procedure. The agreement covers ''data exchange formats'' which are compatible to the centres' internal data storage and retrieval systems which remain different, optimized at each centre to the available computer facilities and to the needs of the data users. Essential condition for the data exchange is an agreement on common procedures for the data exchange is an agreement on common procedures for the data compilation, including critical data analysis and validation. The systems described (''EXFOR'', ''ENDF'', ''CINDA'') are used for ''nuclear reaction data'', but the principles used for data compilation and exchange should be valid also for other data types. (author). 24 refs, 4 figs

  1. Cosmological Structure Formation

    Primack, Joel R

    2015-01-01

    LCDM is remarkably successful in predicting the cosmic microwave background and large-scale structure, and LCDM parameters have been determined with only mild tensions between different types of observations. Hydrodynamical simulations starting from cosmological initial conditions are increasingly able to capture the complex interactions between dark matter and baryonic matter in galaxy formation. Simulations with relatively low resolution now succeed in describing the overall galaxy population. For example, the EAGLE simulation in volumes up to 100 cubic Mpc reproduces the observed local galaxy mass function nearly as well as semi-analytic models. It once seemed that galaxies are pretty smooth, that they generally grow in size as they evolve, and that they are a combination of disks and spheroids. But recent HST observations combined with high-resolution hydrodynamic simulations are showing that most star-forming galaxies are very clumpy; that galaxies often undergo compaction which reduces their radius and ...

  2. Synapse formation and remodeling

    2010-01-01

    Synapses are specialized structures that mediate information flow between neurons and target cells,and thus are the basis for neuronal system to execute various functions,including learning and memory.There are around 1011 neurons in the human brain,with each neuron receiving thousands of synaptic inputs,either excitatory or inhibitory.A synapse is an asymmetric structure that is composed of pre-synaptic axon terminals,synaptic cleft,and postsynaptic compartments.Synapse formation involves a number of cell adhesion molecules,extracellular factors,and intracellular signaling or structural proteins.After the establishment of synaptic connections,synapses undergo structural or functional changes,known as synaptic plasticity which is believed to be regulated by neuronal activity and a variety of secreted factors.This review summarizes recent progress in the field of synapse development,with particular emphasis on the work carried out in China during the past 10 years(1999-2009).

  3. Group Formation in Economics

    Demange, Gabrielle; Wooders, Myrna

    2005-01-01

    Broad and diverse ranges of activities are conducted within and by organized groups of individuals, including political, economic and social activities. These activities have recently become a subject of intense interest in economics and game theory. Some of the topics investigated in this collection are models of networks of power and privilege, trade networks, co-authorship networks, buyer-seller networks with differentiated products, and networks of medical innovation and the adaptation of new information. Other topics are social norms on punctuality, clubs and the provision of club goods and public goods, research and development and collusive alliances among corporations, and international alliances and trading agreements. While relatively recent, the literature on game theoretic studies of group formation in economics is already vast. This volume provides an introduction to this important literature on game-theoretic treatments of situations with networks, clubs, and coalitions, including some applications.

  4. Reference Citation Format

    2011-01-01

    <正>The format for citations in text and for bibliographic references follows the Publication Manual of the American Psychological Association(5thEd.,2001)and GB/T 7714-2005.The citation of printed word should be ordered in number as it appears in the text of the submitted article.For journal article1 Goodrum,A.A.,McCain,K.W.,&Lawrence,S.,et al.Scholarly publishing in the Internet age:A citation analysis of computer science literature.Information Processing and Management,2001,37:661-675.2 Fernandez,M.,Kadiyska,Y.,&Suciu,D.,et al.SilkRoute:A framework for publishing relational data in XML.ACM Transactions on Database Systems,2002,27(4):438-493.

  5. Reference Citation Format

    2009-01-01

    <正>The format for citations in text and for bibliographic references follows the Publication Manual of the American Psychological Association(5thEd.,2001)and GB/T 7714-2005.The citation of printed word should be ordered in number as it appears in the text of the submitted article.For journal article1 Goodrum,A.A.,McCain,K.W.,&Lawrence,S.,et al.Scholarly publishing in the Internet age:A citation analysis of computer science literature.Information Processing and Management,2001,37:661-675.2 Fernandez,M.,Kadiyska,Y.,&Suciu,D.,et al.SilkRoute:A framework for publishing relational data in XML.ACM Transactions on Database Systems,2002,27(4):438-493.

  6. Reference Citation Format

    2010-01-01

    <正>The format for citations in text and for bibliographic references follows the Publication Manual of the American Psychological Association(5thEd.,2001)and GB/T 7714-2005.The citation of printed word should be ordered in number as it appears in the text of the submitted article.For journal article1 Goodrum,A.A.,McCain,K.W.,&Lawrence,S.,et al.Scholarly publishing in the Internet age:A citation analysis of computer science literature.Information Processing and Management,2001,37:661-675.2 Fernandez,M.,Kadiyska,Y.,&Suciu,D.,et al.SilkRoute:A framework for publishing relational data in XML.ACM Transactions on Database Systems,2002,27(4):438-493.

  7. Nuclear Pasta Formation

    Schneider, A S; Hughto, J; Berry, D K

    2013-01-01

    The formation of complex nonuniform phases of nuclear matter, known as nuclear pasta, is studied with molecular dynamics simulations containing 51200 nucleons. A phenomenological nuclear interaction is used that reproduces the saturation binding energy and density of nuclear matter. Systems are prepared at an initial density of 0.10fm$^{-3}$ and then the density is decreased by expanding the simulation volume at different rates to densities of 0.01 fm$^{-3}$ or less. An originally uniform system of nuclear matter is observed to form spherical bubbles ("swiss cheese"), hollow tubes, flat plates ("lasagna"), thin rods ("spaghetti") and, finally, nearly spherical nuclei with decreasing density. We explicitly observe nucleation mechanisms, with decreasing density, for these different pasta phase transitions. Topological quantities known as Minkowski functionals are obtained to characterize the pasta shapes. Different pasta shapes are observed depending on the expansion rate. This indicates non equilibrium effects...

  8. Recipes for planet formation

    Meyer, Michael R.

    2009-11-01

    Anyone who has ever used baking soda instead of baking powder when trying to make a cake knows a simple truth: ingredients matter. The same is true for planet formation. Planets are made from the materials that coalesce in a rotating disk around young stars - essentially the "leftovers" from when the stars themselves formed through the gravitational collapse of rotating clouds of gas and dust. The planet-making disk should therefore initially have the same gas-to-dust ratio as the interstellar medium: about 100 to 1, by mass. Similarly, it seems logical that the elemental composition of the disk should match that of the star, reflecting the initial conditions at that particular spot in the galaxy.

  9. Ring enhancement of brain abscess as followed by computerized tomography

    Kawashima, K.; Satoh, S.; Hidaka, T.; Takai, N.; Kamada, K. (Yamagata Prefectural Central Hospital (Japan))

    1981-08-01

    A 39-year-old male was admitted due to brain abscess and was treated nonsurgically. On the CT examination, the intravenous injection of a contrast material (meglumine amidotrizoate) showed an early ring-form enhancement around the infected locus. Since the ring enhancement associated with brain abscess can be seen both in the late stage of cerebritis and in the formation of the abscess capsule, we tried to determine the process of the capsule formation on the CT image. As a result, the enhancement in the brain abscess by cerebritis appeared heterogeneous in density, and with an irregular, incomplete ring-shaped form, while the matured capsule exhibited a thin but homogeneous and completed ring in the enhanced CT. When the ''full-width half-maximum'' method was used, the ring enhancement in the premature capsule (from the 11th to the 51st day after clinical symptoms appeared) was irregular, incomplete, and ill-shaped. It became a complete and well-shaped ring only at the 60th day. After the appearance of the complete ring, all the clinical symptoms and CSF findings were improved. The size of the ring thereafter shrank significantly, and no enhancement effect was seen at discharge. These observations suggest strongly that the ring enhancement in a brain abscess varies during the course of the disease. The maturation of the capsule formation can be detected in CT image by means of the ''full-width half-maximum'' technique.

  10. Ring enhancement of brain abscess as followed by computerized tomography

    A 39-year-old male was admitted due to brain abscess and was treated nonsurgecally. On the CT examination, the intravenous injection of a contrast material (meglumine amidotrizoate) showed an early ring-form enhancement around the infected locus. Since the ring enhancement associated with brain abscess can be seen both in the late stage of cerebritis and in the formation of the abscess capsule, we tried to determine the process of the capsule formation on the CT image. As a result, the enhancement in the brain abscess by cerebritis appeared heterogeneous in density, and with an irregular, incomplete ring-shaped form, while the matured capsule exhibited a thin but homogeneous and completed ring in the enhanced CT. When the ''full-width half-maximum'' method was used, the ring enhancement in the premature capsule (from the 11th to the 51st day after clinical symptoms appeared) was irregular, incomplete, and ill-shaped. It became a complete and well-shaped ring only at the 60th day. After the appearance of the complete ring, all the clinical symptoms and CSF findings were improved. The size of the ring thereafter shrank significantly, and no enhancement effect was seen at discharge. These observations suggest strongly that the ring enhancement in a brain abscess varies during the course of the disease. The maturation of the capsule formation can be detected in CT image by means of the ''full-width half-maximum'' technique. (author)

  11. Streamer formation in sprites

    McHarg, M. G.; Kammae, T.; Nielsen, H. C.

    2005-12-01

    Models of sprite formation for positive cloud-to-ground lightning strokes predict both downward (positive), and upward (negative) propagating streamers. Previous high speed camera observations of sprites are generally consistent with these predictions, but have been unable to resolve the temporal formation of the streamers due to frame rates limited to a few thousand frames per second. We report observations made during the evening of 9 July 2005 at 10,000 frames per second, with the image intensifier gated to 50 microseconds per frame. These observations often show the streamer head to be a bead-like structure propagating downward at approximately 7x106 m/s for 1,500 microseconds. The bead is followed by a dark region, and the main emissions from the sprite column are delayed ~800 microseconds after the passage of the streamer head. There are also "beads" which clearly propagate upward. Some events appear to be very similar to laboratory images of time resolved streamer zones. We interpret these observations in terms of positive/negative streamers. We see evidence for branching of the streamer tips in several cases, as well as evidence of upward propagating streamers transitioning into a more diffuse emission. Previous work (Pasko and Stenbaek-Nielsen, GRL 29(10), 2002) indicates this transition region has a lower border at an altitude when the dielectric relaxation time scale equals the time scale for an individual electron to develop into a streamer, and an upper border when the dielectric relaxation time scale roughly equals the dissociative attachment time scale. The present observations appear to be broadly consistent with this interpretation.

  12. A Technology Toolkit to support accessibility of formative e-assessment for disabled students

    Draffan, E.A.; Wald, Mike; Newman, Russell; Skuse, Sebastian; Phethean, Christopher

    2010-01-01

    This paper illustrates how problems with accessibility and ease of use of electronic formative assessment tools can be overcome by the judicious use of assistive technologies and presentation modes to enhance teaching and learning for disabled students and those with specific learning difficulties such as dyslexia. Where formative assessments are used to enhance teaching and learning to meet the needs of students, it is important to work in an inclusive environment to support diverse personal...

  13. Word-formation aspects of proper names - Word-formation or name-formation?

    Harvalík, Milan

    Cluj-Napoca: Mega, 2015 - (Felecan, O.), s. 37-43 ISBN 978-606-543-671-8. [Name and Naming /3./ Conventiona/Unconventional in Onomastics. Baia Mare (RO), 01.09.2015-03.09.2015] Institutional support: RVO:68378092 Keywords : proper names * common nouns * word-formation * name-formation * parasystemic formation Subject RIV: AI - Linguistics

  14. EDITORIAL: Nano-enhanced! Nano-enhanced!

    Demming, Anna

    2010-08-01

    In the early 19th century, a series of engineering and scientific breakthroughs by Nicolas Léonard Sadi Carnot, James Watt and many others led to the foundations of thermodynamics and a new pedigree of mechanical designs that reset the standards of engineering efficiency. The result was the industrial revolution. In optical- and electronics- based nanotechnology research, a similarly subtle bargain is being made; we cannot alter the fact that systems have a finite response to external excitations, but what we can do is enhance that response. The promising attributes of ZnO have long been recognised; its large band gap and high exciton binding energy lend it to a number of applications from laser diodes, LEDs, optical waveguides and switches, and acousto-optic applications to sun cream. When this material is grown into nanowires and nanorods, the material gains a whole new dimension, as quantum confinement effects come into play. Discovery of the enhanced radiative recombination, which has potential for exploitation in many optical and opto-electronic applications, drove intensive research into investigating these structures and into finding methods to synthesise them with optimised properties. This research revealed further subtleties in the properties of these materials. One example is the work by researchers in the US reporting synthesis procedures that produced a yield—defined as the weight ratio of ZnO nanowires to the original graphite flakes—of 200%, and which also demonstrated, through photoluminescence analysis of nanowires grown on graphite flakes and substrates, that graphite induces oxygen vacancies during annealing, which enhances the deep-level to near-band-edge emission ratio [1]. Other one-dimensional materials that provide field emission enhancements include carbon nanotubes, and work has been performed to find ways of optimising the emission efficiency from these structures, such as through control of the emitter density [2]. One of the

  15. Amyloid formation: functional friend or fearful foe?

    Bergman, P; Roan, N R; Römling, U; Bevins, C L; Münch, J

    2016-08-01

    Amyloid formation has been most studied in the context of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease, as well as in amyloidosis. However, it is becoming increasingly clear that amyloid is also present in the healthy setting; for example nontoxic amyloid formation is important for melanin synthesis and in innate immunity. Furthermore, bacteria have mechanisms to produce functional amyloid structures with important roles in bacterial physiology and interaction with host cells. Here, we will discuss some novel aspects of fibril-forming proteins in humans and bacteria. First, the amyloid-forming properties of the antimicrobial peptide human defensin 6 (HD6) will be considered. Intriguingly, unlike other antimicrobial peptides, HD6 does not kill bacteria. However, recent data show that HD6 can form amyloid structures at the gut mucosa with strong affinity for bacterial surfaces. These so-called nanonets block bacterial invasion by entangling the bacteria in net-like structures. Next, the role of functional amyloid fibrils in human semen will be discussed. These fibrils were discovered through their property to enhance HIV infection but they may also have other yet unknown functions. Finally, the role of amyloid formation in bacteria will be reviewed. The recent finding that bacteria can make amyloid in a controlled fashion without toxic effects is of particular interest and may have implications for human disease. The role of amyloid in health and disease is beginning to be unravelled, and here, we will review some of the most recent findings in this exciting area. PMID:27151743

  16. Gas formation. Formation temperatures of thermogenic and biogenic methane.

    Stolper, D A; Lawson, M; Davis, C L; Ferreira, A A; Santos Neto, E V; Ellis, G S; Lewan, M D; Martini, A M; Tang, Y; Schoell, M; Sessions, A L; Eiler, J M

    2014-06-27

    Methane is an important greenhouse gas and energy resource generated dominantly by methanogens at low temperatures and through the breakdown of organic molecules at high temperatures. However, methane-formation temperatures in nature are often poorly constrained. We measured formation temperatures of thermogenic and biogenic methane using a "clumped isotope" technique. Thermogenic gases yield formation temperatures between 157° and 221°C, within the nominal gas window, and biogenic gases yield formation temperatures consistent with their comparatively lower-temperature formational environments (<50°C). In systems where gases have migrated and other proxies for gas-generation temperature yield ambiguous results, methane clumped-isotope temperatures distinguish among and allow for independent tests of possible gas-formation models. PMID:24970083

  17. Optimization of culture conditions for Gardnerella vaginalis biofilm formation.

    Machado, Daniela; Palmeira-de-Oliveira, Ana; Cerca, Nuno

    2015-11-01

    Bacterial vaginosis is the leading vaginal disorder in women in reproductive age. Although bacterial vaginosis is related with presence of a biofilm composed predominantly by Gardnerella vaginalis, there has not been a detailed information addressing the environmental conditions that influence the biofilm formation of this bacterial species. Here, we evaluated the influence of some common culture conditions on G. vaginalis biofilm formation, namely inoculum concentration, incubation period, feeding conditions and culture medium composition. Our results showed that culture conditions strongly influenced G. vaginalis biofilm formation and that biofilm formation was enhanced when starting the culture with a higher inoculum, using a fed-batch system and supplementing the growth medium with maltose. PMID:26381661

  18. Modeling Formation of Globular Clusters: Beacons of Galactic Star Formation

    Gnedin, Oleg Y

    2010-01-01

    Modern hydrodynamic simulations of galaxy formation are able to predict accurately the rates and locations of the assembly of giant molecular clouds in early galaxies. These clouds could host star clusters with the masses and sizes of real globular clusters. I describe current state-of-the-art simulations aimed at understanding the origin of the cluster mass function and metallicity distribution. Metallicity bimodality of globular cluster systems appears to be a natural outcome of hierarchical formation and gradually declining fraction of cold gas in galaxies. Globular cluster formation was most prominent at redshifts z>3, when massive star clusters may have contributed as much as 20% of all galactic star formation.

  19. Using Formative Assessment to Drive Mathematics Instruction in Grades PreK-2

    Oberdorf, Christine; Taylor-Cox, Jennifer

    2012-01-01

    Provide targeted mathematics instruction for every child. These books combine formative assessment with practical activities to differentiate the elementary classroom. The formative assessments include student work samples at varying levels. The authors: (1) Illustrate the distinction between a "traditional" assessment and an "enhanced"…

  20. Using Formative Assessment to Drive Mathematics Instruction in Grades 3-5

    Oberdorf, Christine; Taylor-Cox, Jennifer

    2012-01-01

    This book provides targeted mathematics instruction for every child. This book combines formative assessment with practical activities to differentiate the elementary classroom. The formative assessments include student work samples at varying levels. The authors: (1) Illustrate the distinction between a "traditional" assessment and an "enhanced"…