Influence of the pressure and power on the non-equilibrium plasma chemistry of C{sub 2}, C{sub 2}H, C{sub 2}H{sub 2}, CH{sub 3} and CH{sub 4} affecting the synthesis of nanodiamond thin films from C{sub 2}H{sub 2} (1%)/H{sub 2}/Ar-rich plasmas

Energy Technology Data Exchange (ETDEWEB)

Gordillo-Vazquez, F J [Instituto de Optica, C.S.I.C., Serrano 121, 28006 Madrid (Spain); Albella, J M [Instituto de Materiales de Madrid, C.S.I.C., Cantoblanco, 28049 Madrid (Spain)

2004-02-01

We have used a kinetic model to investigate the influence of changing the pressure (0.1-0.8 Torr) and power (100-300 W) on the non-equilibrium plasma chemistry of RF (13.56 MHz) produced C{sub 2}H{sub 2} (1%)/H{sub 2}/Ar plasmas of interest for the synthesis of nanodiamond thin films. We found that the concentrations of the species C{sub 2}(X{sup 1}SIGMA{sup +}{sub g}), C{sub 2}(a{sup 3}PI{sub u}) and C{sub 2}H are not sensitive to variations in the power but they exhibit a significant increase when the pressure decreases at high argon content in the plasma. In addition, the concentrations of C{sub 2}H{sub 2}, CH{sub 4} and CH{sub 3} exhibit a slight (case of C{sub 2}H{sub 2}) or negligible (case of CH{sub 3} and CH{sub 4}) power-dependence although they decrease (case of C{sub 2}H{sub 2} and CH{sub 4}) or remain almost constant (case of CH{sub 3}) as the pressure decreases. A reasonable agreement is found when comparing the model predictions with available experimental results. These findings provide a basic understanding of the plasma chemistry of hydrocarbon/Ar-rich plasma environments and, at the same time, can be of interest to optimize the processing conditions of nanodiamond films from medium pressure RF hydrocarbon/Ar-rich plasmas.

Photochemical reactivity of aqueous fullerene clusters: C{sub 60} versus C{sub 70}

Energy Technology Data Exchange (ETDEWEB)

Hou, Wen-Che, E-mail: whou@mail.ncku.edu.tw; Huang, Shih-Hong

2017-01-15

Highlights: • Aqueous C{sub 60} and C{sub 70} clusters (nC{sub 60} and nC{sub 70}) formed through direct mixing with water adopted a face-centered cubic crystal structure. • The AQYs of nC{sub 60} were greater than those of nC{sub 70}. • Both nC{sub 60} and nC{sub 70} lost considerable organic carbon contents (>80%) after ∼8 months of outdoor sunlight irradiation. • The intermediate photoproducts of nC{sub 60} and nC{sub 70} exhibited an increased content of oxygen-containing functionalities. - Abstract: Over the past few years, there has been a strong interest in exploring the potential impact of fullerenes in the environment. Despite that both C{sub 60} and C{sub 70} have been detected in environmental matrices, the research on the impact of higher fullerenes, such as C{sub 70,} has been largely missing. This study evaluated and compared the phototransformation of aqueous C{sub 60} and C{sub 70} clusters (nC{sub 60} and nC{sub 70}) and their {sup 1}O{sub 2} production under sunlight and lamp light irradiation (315 nm, 360 nm and 420 nm). The nC{sub 60} and nC{sub 70} samples formed by direct mixing with water adopted a face-centered cubic (FCC) crystal structure. The apparent quantum yields (AQYs) of fullerene phototransformed were relatively constant over the examined wavelengths, while {sup 1}O{sub 2} production AQYs decreased with increased wavelengths. The long-term fate studies with outdoor sunlight indicated that both nC{sub 60} and nC{sub 70} lost considerable organic carbon contents (>80%) in water after ∼8 months of irradiation and that the intermediate photoproducts of nC{sub 60} and nC{sub 70} exhibited a progressively increased level of oxygen-containing functionalities. Overall, the study indicates that nC{sub 70} can be photochemically removed under sunlight conditions and that the photoreactivity of nC{sub 60} based on AQYs is greater than that of nC{sub 70}.

Synthesis of (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)olivetolic acid, methyl (1'-/sup 13/C)olivetolate and (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)cannabigerolic acid

Energy Technology Data Exchange (ETDEWEB)

Porwoll, J P; Leete, E [Minnesota Univ., Minneapolis (USA). Dept. of Chemistry

1985-03-01

Potential advanced intermediates in the biosynthesis of delta/sup 9/-tetrahydrocannabinol, the major psychoactive principle of marijuana, have been synthesized labeled with two contiguous /sup 13/C atoms and /sup 14/C. Methyl (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)olivetolate was prepared from lithium (/sup 13/C/sub 2/)acetylide and dimethyl (2-/sup 14/C)malonate. Reaction with geranyl bromide afforded methyl (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)cannabigerolate, and hydrolysis of these methyl esters with lithium propyl mercaptide yielded the corresponding labeled acids. The /sup 13/C-/sup 13/C couplings observable in the /sup 13/C NMR spectra of these /sup 13/C-enriched compounds and their synthetic precursors are recorded. Methyl (1'-/sup 14/C)olivetolate was prepared from /sup 13/CO/sub 2/ to confirm assignments of the /sup 13/C chemical shifts in the pentyl side chain of these compounds.

Synthesis of (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)olivetolic acid, methyl (1'-/sup 13/C)olivetolate and (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)cannabigerolic acid

Energy Technology Data Exchange (ETDEWEB)

Porwoll, J.P.; Leete, E. (Minnesota Univ., Minneapolis (USA). Dept. of Chemistry)

1985-03-01

Potential advanced intermediates in the biosynthesis of delta/sup 9/-tetrahydrocannabinol, the major psychoactive principle of marijuana, have been synthesized labeled with two contiguous /sup 13/C atoms and /sup 14/C. Methyl (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)olivetolate was prepared from lithium (/sup 13/C/sub 2/)acetylide and dimethyl (2-/sup 14/C)malonate. Reaction with geranyl bromide afforded methyl (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)cannabigerolate, and hydrolysis of these methyl esters with lithium propyl mercaptide yielded the corresponding labeled acids. The /sup 13/C-/sup 13/C couplings observable in the /sup 13/C NMR spectra of these /sup 13/C-enriched compounds and their synthetic precursors are recorded. Methyl (1'-/sup 14/C)olivetolate was prepared from /sup 13/CO/sub 2/ to confirm assignments of the /sup 13/C chemical shifts in the pentyl side chain of these compounds.

On C{sub J} and C{sub T} in conformal QED

Energy Technology Data Exchange (ETDEWEB)

Giombi, Simone; Tarnopolsky, Grigory [Princeton University, Department of Physics,Jadwin Hall, Washington Road, Princeton NJ 08544 (United States); Klebanov, Igor R. [Princeton University, Department of Physics,Jadwin Hall, Washington Road, Princeton NJ 08544 (United States); Princeton Center for Theoretical Science, Princeton University,Jadwin Hall, Washington Road, Princeton NJ 08544 (United States)

2016-08-26

QED with a large number N of massless fermionic degrees of freedom has a conformal phase in a range of space-time dimensions. We use a large N diagrammatic approach to calculate the leading corrections to C{sub T}, the coefficient of the two-point function of the stress-energy tensor, and C{sub J}, the coefficient of the two-point function of the global symmetry current. We present explicit formulae as a function of d and check them versus the expectations in 2 and 4−ϵ dimensions. Using our results in higher even dimensions we find a concise formula for C{sub T} of the conformal Maxwell theory with higher derivative action F{sub μν}(−∇{sup 2}){sup (d/2)−2}F{sup μν}. In d=3, QED has a topological symmetry current, and we calculate the correction to its two-point function coefficient, C{sub J}{sup top}. We also show that some RG flows involving QED in d=3 obey C{sub T}{sup UV}>C{sub T}{sup IR} and discuss possible implications of this inequality for the symmetry breaking at small values of N.

Fullerene C{sub 70} decorated TiO{sub 2} nanowires for visible-light-responsive photocatalyst

Energy Technology Data Exchange (ETDEWEB)

Cho, Er-Chieh [Department of Clinical Pharmacy, School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei 110, Taiwan (China); Ciou, Jing-Hao [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Zheng, Jia-Huei; Pan, Job [Department of Clinical Pharmacy, School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei 110, Taiwan (China); Hsiao, Yu-Sheng, E-mail: yshsiao@mail.mcut.edu.tw [Department of Materials Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan (China); Lee, Kuen-Chan, E-mail: kclee@kmu.edu.tw [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Huang, Jen-Hsien, E-mail: 295604@cpc.com.tw [Department of Green Material Technology, Green Technology Research Institute, CPC Corporation, Kaohsiung 30010, Taiwan (China)

2015-11-15

Graphical abstract: - Highlights: • TiO{sub 2} nanowire decorated with C{sub 60} and C{sub 70} derivatives has been synthesized. • The fullerenes impede the charge recombination due to its high electron affinity. • The fullerenes expand the utilization of solar light from UV to visible light. • The modified-TiO{sub 2} has great biocompatibility. - Abstract: In this study, we have synthesized C{sub 60} and C{sub 70}-modified TiO{sub 2} nanowire (NW) through interfacial chemical bonding. The results indicate that the fullerenes (C{sub 60} and C{sub 70} derivatives) can act as sinks for photogenerated electrons in TiO{sub 2}, while the fullerene/TiO{sub 2} is illuminated under ultraviolet (UV) light. Therefore, in comparison to the pure TiO{sub 2} NWs, the modified TiO{sub 2} NWs display a higher photocatalytic activity under UV irradiation. Moreover, the fullerenes also can function as a sensitizer to TiO{sub 2} which expand the utilization of solar light from UV to visible light. The results reveal that the C{sub 70}/TiO{sub 2} NWs show a significant photocatalytic activity for degradation of methylene blue (MB) in visible light region. To better understand the mechanism responsible for the effect of fullerenes on the photocatalytic properties of TiO{sub 2}, the electron only devices and photoelectrochemical cells based on fullerenes/TiO{sub 2} are also fabricated and evaluated.

Heterogeneous catalytic epoxidation of C/sub 8/-C/sub 1/4 olefins by tert. -butyl hydroperoxide

Energy Technology Data Exchange (ETDEWEB)

Dahlmann, J; Hoeft, E; Boeden, H F; Dilcher, H

1979-09-01

Heterogeneous catalytic epoxidation of C/sub 8/-C/sub 14/ olefins by tert.-butyl hydroperoxide (TBHP) avoids large product losses to side reactions, associated with the use of homogeneous catalysts, such as Mo(CO)/sub 6/. With an unsupported MoO/sub 3/ catalyst, 48% TBHP conversion was achieved after one hour (vs. 24% after two hours for Mo(CO)/sub 6/) in 1-octene epoxidation at 90/sup 0/C and 2:1:3 octene/TBHP/toluene (solvent) molar ratio. The use of silica-supported catalysts, such as Bi/sub 9/PMo/sub 12/O/sub 52//30% SiO/sub 2/ (ACN, an industrial catalyst for acrylonitrile), MoO/sub 3//30% SiO/sub 2/ (D-1), 3MoO/sub 3/-Sb/sub 2/O/sub 5//50% SiO/sub 2/ (D-2), or 2MoO/sub 3/-As/sub 2/O/sub 3//50% SiO/sub 2/ (D-3) increased the conversion to 68, 67, 70, and 73%, respectively, with up to 95-99% selectivities for the epoxide. Under optimum conditions of 3:1 olefin/TBHP, 110/sup 0/C, and 2-4 g/l. catalyst, TBHP conversions in epoxidation of 1-tetradecene in a batch reactor over ACN, D-2, and D-3 after two hours were 94, 88, and 91%, respectively, but they decreased to 52, 78, and 79%, respectively, after five two-hour operating cycles. In epoxidation of 1-decene or a mixture of decene isomers (a model for the industrial olefin mixtures obtained by paraffin dehydrogenation via the Parex process) carried out in a continuous flow reactor over the D-3 catalyst at 90/sup 0/-110/sup 0/C, stable catalytic activities with TBHP conversions of approx. 90% and 90-96% selectivities for epoxides were observed for about 900 hr.

C{sub 60} AS A PROBE FOR ASTROPHYSICAL ENVIRONMENTS

Energy Technology Data Exchange (ETDEWEB)

Brieva, A. C.; Jäger, C.; Huisken, F. [Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 3, D-07743 Jena (Germany); Gredel, R.; Henning, T., E-mail: aab01@alumni.aber.ac.uk [Max Planck Institute for Astronomy (MPIA), Königstuhl 17, D-69117 Heidelberg (Germany)

2016-08-01

The C{sub 60} molecule has been recently detected in a wide range of astrophysical environments through its four active intramolecular vibrational modes ( T {sub 1u}) near 18.9, 17.4, 8.5, and 7.0 μ m. The strengths of the mid-infrared emission bands have been used to infer astrophysical conditions in the fullerene-rich regions. Widely varying values of the relative intrinsic strengths (RIS) of these four bands are reported in laboratory and theoretical papers, which impedes the derivation of the excitation mechanism of C{sub 60} in the astrophysical sources. The spectroscopic analysis of the C{sub 60} samples produced with our method delivers highly reproducible RIS values of 100, 25 ± 1, 26 ± 1 and 40 ± 4. A comparison of the inferred C{sub 60} emission band strengths with the astrophysical data shows that the observed strengths cannot be explained in terms of fluorescent or thermal emission alone. The large range in the observed 17.4 μ m/18.9 μ m emission ratios indicates that either the emission bands contain significant contributions from emitters other than C{sub 60}, or that the population distribution among the C{sub 60} vibrational modes is affected by physical processes other than thermal or UV excitation, such as chemo-luminescence from nascent C{sub 60} or possibly Poincaré fluorescence resulting from an inverse internal energy conversion. We have carefully analyzed the effect of the weakly active fundamental modes and second order modes in the mid-infrared spectrum of C{sub 60}, and propose that neutral C{sub 60} is the carrier of the unidentified emission band at 6.49 μ m which has been observed in fullerene-rich environments.

Climate change, phenology, and butterfly host plant utilization.

Science.gov (United States)

Navarro-Cano, Jose A; Karlsson, Bengt; Posledovich, Diana; Toftegaard, Tenna; Wiklund, Christer; Ehrlén, Johan; Gotthard, Karl

2015-01-01

Knowledge of how species interactions are influenced by climate warming is paramount to understand current biodiversity changes. We review phenological changes of Swedish butterflies during the latest decades and explore potential climate effects on butterfly-host plant interactions using the Orange tip butterfly Anthocharis cardamines and its host plants as a model system. This butterfly has advanced its appearance dates substantially, and its mean flight date shows a positive correlation with latitude. We show that there is a large latitudinal variation in host use and that butterfly populations select plant individuals based on their flowering phenology. We conclude that A. cardamines is a phenological specialist but a host species generalist. This implies that thermal plasticity for spring development influences host utilization of the butterfly through effects on the phenological matching with its host plants. However, the host utilization strategy of A. cardamines appears to render it resilient to relatively large variation in climate.

The role of carbonic anhydrase in C>4 photosynthesis

Energy Technology Data Exchange (ETDEWEB)

Studer, Anthony [Life Sciences Research Foundation, Baltimore, MD (United States)

2015-10-01

Current pressures on the global food supply have accelerated the urgency for a second green revolution using novel and sustainable approaches to increase crop yield and efficiency. This proposal outlines experiments to address fundamental questions regarding the biology of C>4 photosynthesis, the method of carbon fixation utilized by the most productive food, feed and bioenergy crops. Carbonic anhydrase (CA) has been implicated in multiple cellular functions including nitrogen metabolism, water use efficiency, and photosynthesis. CA catalyzes the first dedicated step in C>4 photosynthesis, the hydration of CO₂ into bicarbonate, and is potentially rate limiting in C>4 grasses. Using insertional mutagenesis, we have generated CA mutants in maize, and propose the characterization of these mutants using phenotypic, physiological, and transcriptomic profiling to assay the plant’s response to altered CA activity. In addition, florescent protein tagging experiments will be employed to study the subcellular localization of CA paralogs, providing critical data for modeling carbon fixation in C>4 plants. Finally, I propose parallel experiments in Setaria viridis to explore its relevance as model C>4 grass. Using a multifaceted approach, this proposal addresses important questions in basic biology, as well as the need for translation research in response to looming global food challenges.

Plasticity in host utilization by two host-associated populations of Aphis gossypii Glover.

Science.gov (United States)

Barman, A K; Gadhave, K R; Dutta, B; Srinivasan, R

2018-06-01

Biological and morphological plasticity in polyphagous insect herbivores allow them to exploit diverse host plant species. Geographical differences in resource availability can lead to preferential host exploitation and result in inconsistent host specialization. Biological and molecular data provide insights into specialization and plasticity of such herbivore populations. In agricultural landscapes, Aphis gossypii encounters several crop and non-crop hosts, which exist in temporal and spatial proximity. We investigated the host-specialization of two A. gossypii host-associated populations (HAPs), which were field collected from cotton and squash (cotton-associated population and melon-associated population), and later maintained separately in the greenhouse. The two aphid populations were exposed to seven plant species (cotton, okra, watermelon, squash, cucumber, pigweed, and morning glory), and evaluated for their host utilization plasticity by estimating aphid's fitness parameters (nymphal period, adult period, fecundity, and intrinsic rate of increase). Four phenotypical characters (body length, head capsule width, hind tibia length and cornicle length) were also measured from the resulting 14 different HAP × host plant combinations. Phylogenetic analysis of mitochondrial COI sequences showed no genetic variation between the two HAPs. Fitness parameters indicated a significant variation between the two aphid populations, and the variation was influenced by host plants. The performance of melon-aphids was poor (up to 89% reduction in fecundity) on malvaceous hosts, cotton and okra. However, cotton-aphids performed better on cucurbitaceous hosts, squash and watermelon (up to 66% increased fecundity) compared with the natal host, cotton. Both HAPs were able to reproduce on two weed hosts. Cotton-aphids were smaller than melon-aphids irrespective of their host plants. Results from this study suggest that the two HAPs in the study area do not have strict host

Hydrogenation and Deuteration of C{sub 2}H{sub 2} and C{sub 2}H{sub 4} on Cold Grains: A Clue to the Formation Mechanism of C{sub 2}H{sub 6} with Astronomical Interest

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Hitomi; Kawakita, Hideyo [Koyama Astronomical Observatory, Kyoto Sangyo University Motoyama, Kamigamo, Kita-ku, Kyoto 603-8555 (Japan); Hidaka, Hiroshi; Hama, Tetsuya; Watanabe, Naoki [Institute of Low Temperature Science, Hokkaido University N19-W8, Kita-ku, Sapporo, Hokkaido 060-0819 (Japan); Lamberts, Thanja; Kästner, Johannes, E-mail: h_kobayashi@kyoto-nijikoubou.com [Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart (Germany)

2017-03-10

We quantitatively investigated the hydrogen addition reactions of acetylene (C{sub 2}H{sub 2}) and ethylene (C{sub 2}H{sub 4}) on amorphous solid water (ASW) at 10 and 20 K relevant to the formation of ethane (C{sub 2}H{sub 6}) on interstellar icy grains. We found that the ASW surface enhances the reaction rates for C{sub 2}H{sub 2} and C{sub 2}H{sub 4} by approximately a factor of 2 compared to those on the pure-solid C{sub 2}H{sub 2} and C{sub 2}H{sub 4} at 10 K, probably due to an increase in the sticking coefficient and adsorption energy of the H atoms on ASW. In contrast to the previous proposal that the hydrogenation rate of C{sub 2}H{sub 4} is orders of magnitude larger than that of C{sub 2}H{sub 2}, the present results show that the difference in hydrogenation rates of C{sub 2}H{sub 2} and C{sub 2}H{sub 4} is only within a factor of 3 on both the surfaces of pure solids and ASW. In addition, we found the small kinetic isotope effect for hydrogenation/deuteration of C{sub 2}H{sub 2} and C{sub 2}H{sub 4} at 10 K, despite the requirement of quantum tunneling. At 20 K, the reaction rate of deuteration becomes even larger than that of hydrogenation. These unusual isotope effects might originate from a slightly larger number density of D atoms than H atoms on ASW at 20 K. The hydrogenation of C{sub 2}H{sub 2} is four times faster than CO hydrogenation and can produce C{sub 2}H{sub 6} efficiently through C{sub 2}H{sub 4} even in the environment of a dark molecular cloud.

Optical and photoelectrical studies of gold nanoparticle-decorated C{sub 60} films

Energy Technology Data Exchange (ETDEWEB)

Dmitruk, N.L., E-mail: dmitruk@isp.kiev.u [Institute for Physics of Semiconductors, National Academy of Sciences of Ukraine, 45 Nauki Prospect, Kyiv 03028 (Ukraine); Borkovskaya, O.Yu.; Mamykin, S.V.; Naumenko, D.O. [Institute for Physics of Semiconductors, National Academy of Sciences of Ukraine, 45 Nauki Prospect, Kyiv 03028 (Ukraine); Meza-Laguna, V. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (UNAM), Circuito Exterior, Ciudad Universitaria, A. P. 70-186, C. P. 04510 Mexico D.F. (Mexico); Basiuk Golovataya-Dzhymbeeva, E.V. [Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico (UNAM), Circuito exterior S/N Ciudad Universitaria, A. P. 70-186, C. P. 04510 Mexico D.F. (Mexico); Lee, I. Puente [Facultad de Quimica, UNAM, Circuito de la Investigacion Cientifica, Ciudad Universitaria, 04510 Mexico D.F. (Mexico)

2010-01-01

Optical and photoelectrical studies were performed on octane-1,8-dithiol cross-linked fullerene films, with supported gold nanoparticles (C{sub 60}-DT-Au). According to high-resolution transmission electron microscopy observations, the average size of obtained gold nanoparticles was about 5 nm, and the shape was spherical. The comparative investigation of optical properties of pristine and cross-linked with octane-1,8-dithiol C{sub 60} films, decorated with gold nanoparticles, found the difference in the extinction coefficient spectra, which was observed also in the photocurrent spectra of barrier heterostructure Au/C{sub 60}/Si. The analysis of dark current-voltage characteristics for Au/C{sub 60}/Si heterostructures showed that the model for them includes the barrier at the C{sub 60}/Si interface and internal barriers in the C{sub 60} layer, caused by the trapping centers. The hopping mechanism of the current transport in the C{sub 60} layer was supplemented with the Poole-Frenkel emission process on these centers, with the barrier height greater for the fullerene C{sub 60} film cross-linked with octane-1,8-dithiol.

Application of C{sub 60}, C{sub 72} and carbon nanotubes as anode for lithium-ion batteries: A DFT study

Energy Technology Data Exchange (ETDEWEB)

Najafi, Meysam, E-mail: meysamnajafi2016@gmail.com

2017-07-01

The application of C{sub 60}, C{sub 72}, CNT (8, 0) and CNT (10, 0) as anode materials for Lithium-ion batteries were investigated by density functional theory (DFT) calculations. Results show that the average values of voltage cell (V{sub cell}) and adsorption energy (E{sub ad}) of CNT (8, 0) and CNT (10, 0) were higher than C{sub 60} and C{sub 72} ca 0.327 V and 6.52 kcal/mol, respectively. The NH{sub 2} functionalization of studied nanostructures as a strategy to improve the performance of these systems as anode materials of Lithium-ion batteries were investigated. Results show that, NH{sub 2} functionalization of studied nanostructures increase the average values of voltage cell and adsorption energy ca 0.197 V and 8.20 kcal/mol, respectively. Obtained results propose that NH{sub 2} functionalized C{sub 72} and CNT (10, 0) have larger V{sub cell} and E{sub ad} values and therefore these nanostructures have higher potential as anode material for Lithium-ion battery. - Highlights: • C{sub 60} and CNT (10, 0) as anode materials for Lithium-ion batteries were investigated. • V{sub cell} and E{sub ad} of CNT (8, 0) and CNT (10, 0) were higher than C{sub 60} and C{sub 72} ca. • NH{sub 2} functionalization of C{sub 60} improve the performance of it as anode materials of Lithium-ion batteries.

Highly crystalline mesoporous C{sub 60} with ordered pores. A class of nanomaterials for energy applications

Energy Technology Data Exchange (ETDEWEB)

Benzigar, Mercy R.; Joseph, Stalin; Ilbeygi, Hamid [Future Industries Institute (FII), Division of Information Technology Energy and Environment (DivITEE), University of South Australia, Adelaide, SA (Australia); Park, Dae-Hwan; Talapaneni, Siddulu Naidu [Global Innovative Center for Advanced Nanomaterials (GICAN), Faculty of Engineering and Built Environment, The University of Newcastle, Callaghan, NSW (Australia); Sarkar, Sujoy; Chandra, Goutam; Umapathy, Siva; Srinivasan, Sampath [Department of Inorganic and Physical Chemistry and Department of Instrumentation and Applied Physics, Indian Institute of Science (IISc), Bangalore (India); Vinu, Ajayan [Future Industries Institute (FII), Division of Information Technology Energy and Environment (DivITEE), University of South Australia, Adelaide, SA (Australia); Global Innovative Center for Advanced Nanomaterials (GICAN), Faculty of Engineering and Built Environment, The University of Newcastle, Callaghan, NSW (Australia)

2018-01-08

Highly ordered mesoporous C{sub 60} with a well-ordered porous structure and a high crystallinity is prepared through the nanohard templating method using a saturated solution of C{sub 60} in 1-chloronaphthalene (51 mg mL{sup -1}) as a C{sub 60} precursor and SBA-15 as a hard template. The high solubility of C{sub 60} in 1-chloronaphthalene helps not only to encapsulate a huge amount of the C{sub 60} into the mesopores of the template but also supports the oligomerization of C{sub 60} and the formation of crystalline walls made of C{sub 60}. The obtained mesoporous C{sub 60} exhibits a rod-shaped morphology, a high specific surface area (680 m{sup 2} g{sup -1}), tuneable pores, and a highly crystalline wall structure. This exciting ordered mesoporous C{sub 60} offers high supercapacitive performance and a high selectivity to H{sub 2}O{sub 2} production and methanol tolerance for ORR. This simple strategy could be adopted to make a series of mesoporous fullerenes with different structures and carbon atoms as a new class of energy materials. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Transmission properties of C{sub 60} ions through micro- and nano-capillaries

Energy Technology Data Exchange (ETDEWEB)

Tsuchida, Hidetsugu, E-mail: tsuchida@nucleng.kyoto-u.ac.jp [Quantum Science and Engineering Center, Kyoto University, Uji, Kyoto 611-0011 (Japan); Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Majima, Takuya [Quantum Science and Engineering Center, Kyoto University, Uji, Kyoto 611-0011 (Japan); Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Tomita, Shigeo [Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Sasa, Kimikazu [Tandem Accelerator Complex, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Narumi, Kazumasa; Saitoh, Yuichi; Chiba, Atsuya; Yamada, Keisuke [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Hirata, Koichi [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565 (Japan); Shibata, Hiromi [Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan); Itoh, Akio [Quantum Science and Engineering Center, Kyoto University, Uji, Kyoto 611-0011 (Japan); Department of Nuclear Engineering, Kyoto University, Kyoto 615-8530 (Japan)

2013-11-15

We apply the capillary beam-focusing method for the C{sub 60} fullerene projectiles in the velocity range between 0.14 and 0.2 a.u. We study the C{sub 60} transmission properties through two different types of capillaries: (1) borosilicate glass microcapillary with an outlet diameter of 5.5 μm, and (2) Al{sub 2}O{sub 3} multi-capillary foil with a pore size of about 70 nm and a high aspect ratio of about 750. We measured the transmitted particle composition by using the electrostatic deflection method combined with the microchannel plate imaging technique. For the experiments with the single microcapillary, the main transmission component is found to be primary C{sub 60} beams that are focused in the area equal to the capillary outlet diameter. Minor components are charge-exchanged C{sub 60} ions and charged or neutral fragments (fullerene-like C{sub 60-2m} and small C{sub n} particles), and their fractions decrease with decreasing the projectile velocity. It is concluded that the C{sub 60} transmission fraction is considerably high for both types of the capillaries in the present velocity range.

Discrepancy between Clambda and Csub(E)

International Nuclear Information System (INIS)

Williams, P.C.

1977-01-01

The conversion factors Clambda and Csub(E) are used in relating ionization chamber readings (M) to absorbed dose in water for measurements made in phantoms irradiated with photons of quality lambda and electrons of mean energy - E respectively. New calculations of Clambda (Nahum, A.E., and Greening, J.R., 1976, Phys. Med. Biol., vol.21, 862) have yielded values which differ by up to 5% from those quoted by ICRU (ICRU, 1969, Report 14, ICRU Publications, P.O. Box 30165, Washington, DC 20014). Nahum and Greening have also pointed out that the recommended values of Clambda and Csub(E) for radiations of approximately the same primary electron energy should be the same, but differ by approximately 4%. Alternative explanations are offered for these discrepancies. If the ICRU values are corrected for the perturbation of the electron flux in the phantom by the introduction of a cavity, the ionization chamber, into the phantom, then the resulting values are in good agreement with those quoted by Nahum and Greening. The discrepancy between Clambda and Csub(E) is the result of inconsistent definitions. The ICRU definition of Csub(E) leads to a dose conversion factor which is dimensionally correct but is based on the assumption that the product M.Nsub(c), where Nsub(c) is the exposure calibration factor for the ionization chamber at the calibration quality, 2MV, can be identified as exposure, whereas this is only true at the calibration quality. More accurate definitions of Clambda and Csub(E) are therefore proposed. (U.K.)

Performance of a C{sub 60}{sup +} ion source on a dynamic SIMS instrument

Energy Technology Data Exchange (ETDEWEB)

Fahey, Albert J. [Surface and Microanalysis Science Division, National Institute of Standards and Technology, 100 Bureau Dr. Stop 8371, Gaithersburg, MD 20899-8371 (United States)]. E-mail: albert.fahey@nist.gov; Gillen, Greg [Surface and Microanalysis Science Division, National Institute of Standards and Technology, 100 Bureau Dr. Stop 8371, Gaithersburg, MD 20899-8371 (United States); Chi, Peter [Surface and Microanalysis Science Division, National Institute of Standards and Technology, 100 Bureau Dr. Stop 8371, Gaithersburg, MD 20899-8371 (United States); Mahoney, Christine M. [Surface and Microanalysis Science Division, National Institute of Standards and Technology, 100 Bureau Dr. Stop 8371, Gaithersburg, MD 20899-8371 (United States)

2006-07-30

An IonOptika C{sub 60}{sup +} ion source has been fitted onto a CAMECA{sup 1} ims-4f. Stable ion beams of C{sub 60}{sup +} and C{sub 60}{sup 2+} have been obtained with typical currents approaching 20nA under conditions that allow for several days of source operation. The beam has been able to be focussed into a spot size of {approx}3{mu}m with an anode voltage of 10keV and scanning ion images have been acquired. We have performed analyses to characterize the performance of C{sub 60}{sup +} and C{sub 60}{sup 2+}. Depth profiles of a Cr-Ni multi-layer and polymer films with C{sub 60}{sup +} have produced excellent results. We have discovered that, under bombardment energies of <12keV on Si, C{sub 60}{sup +} will sputter material from the sample but will also produce deposition at a rate that exceeds the sputter rate. The performance of the source and our experiences with its operation will be discussed and some characteristic analysis data will be shown.

C{sub T} for non-unitary CFTs in higher dimensions

Energy Technology Data Exchange (ETDEWEB)

Osborn, Hugh [Department of Applied Mathematics and Theoretical Physics, Wilberforce Road,Cambridge CB3 0WA, England (United Kingdom); Stergiou, Andreas [Department of Physics, Yale University,New Haven, CT 06520 (United States)

2016-06-13

The coefficient C{sub T} of the conformal energy-momentum tensor two-point function is determined for the non-unitary scalar CFTs with four- and six-derivative kinetic terms. The results match those expected from large-N calculations for the CFTs arising from the O(N) non-linear sigma and Gross-Neveu models in specific even dimensions. C{sub T} is also calculated for the CFT arising from (n−1)-form gauge fields with derivatives in 2n+2 dimensions. Results for (n−1)-form theory extended to general dimensions as a non-gauge-invariant CFT are also obtained; the resulting C{sub T} differs from that for the gauge-invariant theory. The construction of conformal primaries by subtracting descendants of lower-dimension primaries is also discussed. For free theories this also leads to an alternative construction of the energy-momentum tensor, which can be quite involved for higher-derivative theories.

Photodetachment of negative C{sub 60}{sup -} ions

Energy Technology Data Exchange (ETDEWEB)

Amusia, M.Ya.; Baltenkov, A.S.; Krakov, B.G. [Ioffe Physico-Technical Inst., St. Petersburg (Russian Federation)]|[U.A. Arifov Institute of Electronics, Tashkent, 700143 (Uzbekistan)

1998-06-15

A model that describes the electron structure of negative fullerene C{sub 60}{sup -} ions is proposed. The model contains only two experimentally observed parameters, namely the fullerene radius and the affinity energy of the electron to neutral C{sub 60}. In the frame of this model, cross sections are calculated of elastic scattering of slow electrons on neutral fullerene, of C{sub 60}{sup -} photodetachment near the threshold of this process and of radiative recombination of slow electrons with neutral fullerenes. (orig.) 21 refs.

A quantum group approach to c{sub L} > 1 Liouville gravity

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Takashi

1995-03-01

A candidate of c{sub L} > 1 Liouville gravity is studied via infinite dimensional representations of U{sub q}sl(2, C) with q at a root of unity. We show that vertex operators in this Liouville theory are factorized into classical vertex operators and those which are constructed from finite dimensional representations of U{sub q}sl(2, C). Expressions of correlation functions and transition amplitudes are presented. We discuss about our results and find an intimate relation between our quantization of the Liouville theory and the geometric quantization of moduli space of Riemann surfaces. An interpretation of quantum space-time is also given within this formulation. (author).

On schizosymmetric superfields and sl(2/1, C){sub R} supersymmetry

Energy Technology Data Exchange (ETDEWEB)

Jarvis, P.D. [School of Mathematics and Physics, University of Tasmania, Hobart, TAS (Australia); Fienberg, K.S. [School of Mathematics and Physics, University of Tasmania, Hobart, TAS (Australia); School of Geography and Environmental Studies, University of Tasmania, Hobart, TAS (Australia)

2001-05-11

Superfield expansions over four-dimensional graded spacetime (x{sup {mu}}, {theta}{sup {nu}}), with Minkowski coordinates x extended by vector Grassmann variables {theta}, are investigated. By appropriate identification of the physical Lorentz algebra in the even and odd parts of the superfield, a typology of 'schizofields' containing both integer and half-integer spin fields is established. For two of these types, identified as 'gauge potential'-like and 'field strength'-like schizofields, an sl(2/1, C){sub R} supersymmetry at the component field level is demonstrated. Prospects for a schizofield calculus, and application of these types of field to the particle spectrum, are adumbrated. (author)

C{sub 60}-based ebselen derivative: synthesis by bingel cyclopropanation and enhanced antioxidative and neuroprotective activity

Energy Technology Data Exchange (ETDEWEB)

Xufeng Liu [HuaZhong University of Science and Technology, Wuhan (China). Dept. of Chemistry; Wenchao Guan [Ministry of Education, Wuhan, (China). Hubei University. Key Lab. for the Synthesis and Application of Organic Functional Molecules]. E-mail: wcguan04@yahoo.com.cn; Wengshan Ke [Hubei University, Wuhan (China). College of Life Science

2007-07-01

C{sub 60}-based ebselen derivative 3 was synthesized through Bingel cyclopropanation of C{sub 60} with the ebselen malonate 2. Compound 3 was obtained in 42% yield (based on consumed C{sub 60}) in a three-step synthesis starting from 2-(chloroseleno)benzoyl chloride and 2-(2aminoethoxy)ethanol. Its structure was confirmed by {sup 1H} NMR, {sup 13}C NMR, IR, UV and FAB-MS spectroscopy analyses. In order to verify the enhanced antioxidative and neuroprotective activity of 3, a C{sub 60} derivative (4), an ebselen derivative (2), and their mixture (4 plus 2 in equimolar ratio) were employed to treat cortical neuronal cells, following the same procedure used with 3 and at the same final concentration (30 {mu}mol L{sup -1}). Cell viabilities of the four treated groups were estimated by LDH (lactic dehydrogenase) leakage and MTT (3-(4, 5-dimethylthiazole-2yl)-2,5-diphenyl-tetrazolium bromide) assays. Results showed that the antioxidative and protective activities of C{sub 60}-based ebselen derivative 3 against H{sub 2}O{sub 2}-mediated neuronal injury (MTT(OD) 0.364 {+-} 0.028; LDH release (UL{sup -1}) 4.66 {+-} 0.28) were significantly higher than those of C{sub 6})0 derivative 4 (MTT(OD) 0.324 {+-} 0.025; LDH release (UL{sup -1}) 5.39 {+-} 0.17), ebselen derivative 2 (MTT(OD) 0.294 {+-} 0.021; LDH release (UL{sup -1}) 5.71 {+-} 0.27), and the mixture of 4 and 2 (MTT(OD) 0.310 {+-} 0.018; LDH release (UL{sup -1}) 5.54 {+-}0.39). These findings demonstrated that the combination of two molecular units with similar biological activities (C{sub 60} and ebselen) may be a desirable way of obtaining new and more biologically effective C{sub 60}-based compounds. (author)

Metabolic and morphological alterations induced by proteolysis-inducing factor from Walker tumour-bearing rats in C{sub 2}C{sub 12} myotubes

Energy Technology Data Exchange (ETDEWEB)

Yano, Claudia L; Ventrucci, Gislaine [Departamento de Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, 13083-970, Campinas, São Paulo (Brazil); Field, William N; Tisdale, Michael J [Cancer Research Laboratory, Pharmaceutical Sciences Research Institute, Aston University, Birmingham, B4 7ET (United Kingdom); Gomes-Marcondes, Maria Cristina C [Departamento de Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, 13083-970, Campinas, São Paulo (Brazil)

2008-01-28

Patients with advanced cancer suffer from cachexia, which is characterised by a marked weight loss, and is invariably associated with the presence of tumoral and humoral factors which are mainly responsible for the depletion of fat stores and muscular tissue. In this work, we used cytotoxicity and enzymatic assays and morphological analysis to examine the effects of a proteolysis-inducing factor (PIF)-like molecule purified from ascitic fluid of Walker tumour-bearing rats (WF), which has been suggested to be responsible for muscle atrophy, on cultured C{sub 2}C{sub 12} muscle cells. WF decreased the viability of C{sub 2}C{sub 12} myotubes, especially at concentrations of 20–25 μg.mL{sup -1}. There was an increase in the content of the pro-oxidant malondialdehyde, and a decrease in antioxidant enzyme activity. Myotubes protein synthesis decreased and protein degradation increased together with an enhanced in the chymotrypsin-like enzyme activity, a measure of functional proteasome activity, after treatment with WF. Morphological alterations such as cell retraction and the presence of numerous cells in suspension were observed, particularly at high WF concentrations. These results indicate that WF has similar effects to those of proteolysis-inducing factor, but is less potent than the latter. Further studies are required to determine the precise role of WF in this experimental model.

Fullerene (C{sub 60})/CdS nanocomposite with enhanced photocatalytic activity and stability

Energy Technology Data Exchange (ETDEWEB)

Cai, Qiang [Key Laboratory of Advanced Ceramics and Machining Technology, Ministry of Education, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Hu, Zhuofeng, E-mail: st04hzhf@gmail.com [Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (China); Zhang, Qian; Li, Boyuan [Key Laboratory of Advanced Ceramics and Machining Technology, Ministry of Education, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Shen, Zhurui, E-mail: shenzhurui@tju.edu.cn [Key Laboratory of Advanced Ceramics and Machining Technology, Ministry of Education, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)

2017-05-01

Highlights: • C{sub 60}/CdS nanocomposite has been fabricated as a novel visible-light-driven photocatalyst. • It exhibits enhanced photocatalytic activity and photostability than that of pure CdS reference. • The C{sub 60} improved the charge separation and transfer of nanocomposite due to its high electron affinity. - Abstract: Herein, the fullerene (C{sub 60})/CdS nanocomposite has been fabricated by a facile one-pot hydrothermal method. Its photocatatlytic hydrogen (H{sub 2}) evolution rate and degradation efficiency of Rhodamine B (Rh B) are evaluated under visible light irradiation (λ ≥ 420 nm). The content of C{sub 60} has been changed from 0.4 wt% to 8 wt%, and the optimal value for photocatalytic activity is determined to be 0.4 wt%. The H{sub 2} evolution rate over this optimal sample reaches 1.73 mmol h{sup −1} g{sup −1} and its apparent degradation rate of Rh B is 0.089 min{sup −1} (degradation efficiency of 97% within 40 min), which is 2.3 times and 1.5 times compared to that of pure CdS reference. Moreover, the photocorrosion of CdS in composite is effectively suppressed, and its photocatalytic activity can be well maintained after three recycles (97.8% retaining for composite vs. 84.4% retaining for CdS). Then, the enhanced photocatalytic activity and stability of C{sub 60}/CdS nanocomposite are further studied by spectroscopic and electrochemical methods. Results show that the C{sub 60} species covering on the surface of CdS can efficiently accelerate the separation and transfer of photoexcited charge carriers, which can improve its activity, and reduce the photocorrosion of CdS.

Carbonyltrichlorotris(dimethylphenylphosphine)technetium-ethanol (1/1), the first seven-coordinate complex of technetium; position of this molecule in the Csub(3v) family

Energy Technology Data Exchange (ETDEWEB)

Bandoli, G; Clemente, D A; Mazzi, U [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi

1978-01-01

The preparation and the crystal and molecular structure of the title complex are reported. The coordination polyhedron is that of a distorted capped octahedron Csub(3v) symmetry). The technetium atom is seven-coordnate and bonded to three phosphine ligands (capped face), three chlorine ligands (uncapped face), and to the carbonyl group, which occupies the unique capping position. Crystals are monoclinic, space group P2/sub 1//c, with cell dimensions a = 11.732(9), b = 11.807(9), c = 23.588(12) A, and ..beta..103.42(8)/sup 0/. The structure has been refined by least squares to a conventional R of 0.093 for 1 794 observed reflections. Metal-ligand bond lengths are: Tc-CO 1.86(2), Tc-C1 2.48(1). and Tc-p 2.44(1) A. Seven coordinate complexes are briefly reviewed: in particular, a description of Csub(3v) symmetry and its distortions has been developed in terms of repulsion theory and the angular-overlap model.

Elucidation of C{sub 2} and CN formation mechanisms in laser-induced plasmas through correlation analysis of carbon isotopic ratio

Energy Technology Data Exchange (ETDEWEB)

Dong, Meirong [School of Electric Power, South China University of Technology, Guangzhou, Guangdong 510640 (China); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Chan, George C.-Y.; Mao, Xianglei; Gonzalez, Jhanis J. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Lu, Jidong [School of Electric Power, South China University of Technology, Guangzhou, Guangdong 510640 (China); Russo, Richard E., E-mail: RERusso@lbl.gov [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

2014-10-01

Laser ablation molecular isotopic spectrometry (LAMIS) was recently reported for rapid isotopic analysis by measuring molecular emission from laser-induced plasmas at atmospheric pressure. With {sup 13}C-labeled benzoic acid as a model sample, this research utilized the LAMIS approach to clarify the formation mechanisms of C{sub 2} and CN molecules during laser ablation of organic materials. Because the isotopic ratios in the molecular bands could deviate from statistical distribution depending on their formation pathways, the dominant mechanism can be identified through a comparison of the experimental observed isotopic patterns in the molecular emission with the theoretical statistical pattern. For C{sub 2} formation, the experimental {sup 12}C{sup 12}C/{sup 13}C{sup 12}C ratios not only support a recombination mechanism through atomic carbon at early delay time but also indicate the presence of other operating mechanisms as the plasma evolves; it is proposed that some of the C{sub 2} molecules are released directly from the aromatic ring of the sample as molecular fragments. In contrast, the temporal profiles in the {sup 12}C/{sup 13}C ratios derived from CN emission exhibited opposite behavior with those derived from C{sub 2} emission, which unambiguously refutes mechanisms that require C{sub 2} as a precursor for CN formation; CN formation likely involves atomic carbon or species with a single carbon atom. - Highlights: • C{sub 2} and CN formation mechanisms during laser ablation of organic material studied • Some C{sub 2} molecules are directly desorbed from the organic compound. • C{sub 2} molecules are not important precursor for CN-radical formation.

A theoretical study on the reaction of diazocompounds with C{sub 70} fullerene

Energy Technology Data Exchange (ETDEWEB)

Rostami, Zahra, E-mail: zahrarostami.pnu@gmail.com [Department of Chemistry, Payame Noor University (PNU), P. O. Box, 19395-3697 Tehran (Iran, Islamic Republic of); Hosseini, Javad [Department of Chemistry, Tuyserkan Branch, Islamic Azad University, Tuyserkan (Iran, Islamic Republic of); Panahyab, Ataollah [Young Researchers and Elites Club, Central Tehran Branch, Islamic Azad University, Tahran (Iran, Islamic Republic of)

2017-02-01

Highlights: • Functionalization of a C{sub 70} with diazocompounds was studied by DFT. • Stability [5,6]-fulleroids shows the same trend to that observed experimentally. • The reaction energy is in the range of −23.3 to −37.7 kcal/mol. • Orbital analysis explains the experimentally observed UV–vis spectrums. • Theoretical {sup 1}H NMR results are in excellent agreement with the experimental. - Abstract: Using density functional theory calculations, we investigated the chemical functionalization of a C{sub 70} fullerene with diazocompounds which has been reported experimentally. The results indicate that the [5,6]-bond of the apex of C{sub 70} is more reactive than the equatorial bonds toward the cycloaddition of the diazocompounds. The energetic stability of phenyl C{sub 71} butyric acid methyl ester (PCBM)-type [5,6]-fulleroids (products) shows the same trend (1 > 2 > 3 > 4) to that observed experimentally. The reaction energy for different isomers of [5,6]-fulleroids is in the range of −23.3 to −37.7 kcal/mol. Our frontier molecular orbital analysis explains the experimentally observed UV–vis spectrums and confirmed the formation of [5,6]-fulleroids rather than [6,6]-methanofullerenes. The electron–hole pair binding energy for C{sub 70} is calculated to be about 0.6 to 0.9 eV. Theoretical {sup 1}H-nuclear magnetic resonance (NMR), in good agreement with the corresponding experimental data, was used to more investigate the structure of the most stable complex.

Production of levulinic acid, furfural, and gamma valerolactone from C.sub.5 and C.sub.6 carbohydrates in mono- and biphasic systems using gamma-valerolactone as a solvent

Science.gov (United States)

Dumesic, James A.; Alonso, David Martin; Gurbuz, Elif I.; Wettstein, Stephanie G.

2013-03-19

A method to make levulinic acid (LA), furfural, or gamma-valerolactone (GVL). React cellulose (and/or other C.sub.6 carbohydrates) or xylose (and/or other C.sub.5 carbohydrates) or combinations thereof in a monophasic reaction medium comprising GVL and an acid; or (ii) a biphasic reaction system comprising an organic layer comprising GVL, and a substantially immiscible aqueous layer. At least a portion of the cellulose (and/or other C.sub.6 carbohydrates), if present, is converted to LA and at least a portion of the xylose (and/or other C.sub.5 carbohydrates), if present, is converted into furfural.

Ebulliometric determination and prediction of (vapor + liquid) equilibria for binary and ternary mixtures containing alcohols (C{sub 1}-C{sub 4}) and dimethyl carbonate

Energy Technology Data Exchange (ETDEWEB)

Matsuda, Hiroyuki, E-mail: matsuda@chem.cst.nihon-u.ac.jp [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Fukano, Makoto; Kikkawa, Shinichiro [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Constantinescu, Dana [Carl von Ossietzky Universitaet Oldenburg, Technische Chemie, D-26111 Oldenburg (Germany); Kurihara, Kiyofumi; Tochigi, Katsumi; Ochi, Kenji [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Gmehling, Juergen [Carl von Ossietzky Universitaet Oldenburg, Technische Chemie, D-26111 Oldenburg (Germany)

2012-01-15

Highlights: > The VLE behavior of systems containing dimethyl carbonate (DMC) was investigated. > VLE data for ternary and binary mixtures containing alcohol and DMC were measured. > Several activity coefficient models were used for data reduction or prediction. > Valley line, i.e., distillation boundary, was observed for the ternary mixture. > Residue curves were calculated to investigate composition profile for distillation. - Abstract: (Vapor + liquid) equilibrium (VLE) data for a ternary mixture, namely {l_brace}methanol + propan-1-ol + dimethyl carbonate (DMC){r_brace}, and four binary mixtures, namely an {l_brace}alcohol (C{sub 3} or C{sub 4}) + DMC{r_brace}, containing the binary constituent mixtures of the ternary mixture, were measured at p = (40.00 to 93.32) kPa using a modified Swietoslawski-type ebulliometer. The experimental data for the binary systems were correlated using the Wilson model. The Wilson model was also applied to the ternary system to predict the VLE behavior using parameters from the binary mixtures. The modified UNIFAC (Dortmund) model was also tested for the predictions of the VLE behavior of the binary and ternary mixtures. In addition, the experimental VLE data for the ternary and constituent binary mixtures were correlated using the extended Redlich-Kister (ERK) model, which can completely represent the azeotropic points. For the ternary system, a comparison of the experimental and the predicted or correlated boiling points obtained using the Wilson and ERK models showed that the ERK model is more accurate. The valley line, i.e., the curve which divides the patterns of vapor-liquid tie lines, was found in the (methanol + propan-1-ol + DMC) system. This valley line could be represented by the ERK model. Finally, the composition profile for simple distillation of this ternary mixture was obtained by analysis of the residue curves from the estimated Wilson parameters of the constituent binary mixtures.

Matrix isolation and theoretical study of the photochemical reactions of C{sub 2}H{sub 3}Br and 1,2-C{sub 2}H{sub 2}Br{sub 2} with CrO{sub 2}Cl{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Lemon, Christine E. [Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, OH 45221 (United States); Goldberg, Nicola [Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, OH 45221 (United States); Klein-Riffle, Evan T. [Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, OH 45221 (United States); Kronberg, Jon K. [Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, OH 45221 (United States); Ault, Bruce S. [Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, OH 45221 (United States)], E-mail: bruce.ault@uc.edu

2006-08-01

The matrix-isolation technique has been combined with infrared spectroscopy and theoretical calculations to characterize the products of the photochemical reactions of C{sub 2}H{sub 3}Br and 1,2-C{sub 2}H{sub 2}Br{sub 2} with CrO{sub 2}Cl{sub 2}. For these systems, oxygen-atom transfer occurred upon visible-near ultraviolet irradiation, yielding bromoacetaldehyde and CrOCl{sub 2} in the former case and bromoacetyl bromide and CrCl{sub 2}O in the latter. For each system, the products were formed in the same matrix cage and strongly interacted to form a distinct molecular complex. No evidence was obtained for the acetyl bromide derivative in the C{sub 2}H{sub 3}Br system, indicating the occurrence of oxygen-atom attack at the less substituted carbon of vinyl bromide, nor was any evidence obtained for the formation of a possible five-membered metallocycle. Two different modes of interaction were explored computationally: {eta}{sup 1} (end-on) to the oxygen atom and {eta}{sup 2} (side-on) to the C=O bond. Theoretical calculations indicated that the {eta}{sup 1} complex of CH{sub 2}BrCHO-CrCl{sub 2}O was 13 kcal mol{sup -1} more stable than the {eta}{sup 2} complex at the B3LYP/6-311++G(d,2p) level of theory. The binding energy of the {eta}{sup 1} complex was found to be 21 kcal mol{sup -1}, compared to 8 kcal mol{sup -1} for the {eta}{sup 2} complex at this level of theory.

The third-order nonlinear optical susceptibility of C{sub 60}-derived nanotubes

Energy Technology Data Exchange (ETDEWEB)

Xiangang, Wan [Nanjing Univ. (China). National Lab. of Solid State Microstructures; [Center for Advanced Studies in Science and Technology of Microstructures, Nanjing (China); Jinming, Dong [Nanjing Univ. (China). National Lab. of Solid State Microstructures; [Center for Advanced Studies in Science and Technology of Microstructures, Nanjing (China); Jie, Jiang [Nanjing Univ., JS (China). Dept. of Physics; Xing, D Y [Nanjing Univ., JS (China). Dept. of Physics

1997-02-01

Using the extended Su-Schrieffer-Heeger (SSH) model and the sum-over-state (SOS) method, we have calculated the third-order nonlinear polarizability {gamma} and its dispersion spectra for C{sub 60}-derived nanotubes, which is one of the narrowest tubes. Our numerical calculations indicate that both symmetry and size of the nanotubes have great effect on the third-order nonlinear polarizability {gamma} spectra. We find that with increasing size, both static {gamma} values and dynamical response peak values increase. When the atom number of the C{sub 60}-derived nanotubes is 140, the static {gamma} value is about 65 times larger than that of C{sub 60}, and the highest peak value of {gamma} (at 3{omega} = 3.52 eV) is about three orders larger than that of C{sub 60}. So, C{sub 60}-derived nanotubes may become a kind of good nonlinear optical materials. (orig.)

Reactive organic air components (C{sub 6}-C{sub 12}) of anthropogenic and biogenic origin in deciduous and coniferous forests. Final report; Reaktive organische Luftkomponenten (C{sub 6}-C{sub 12}) anthropogenen und biogenen Ursprungs in Laub- und Nadelwaeldern. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Steinbrecher, R.; Fehsenfeld, U.; Hauff, K.; Jocher, M.; Kolb, C.; Reichmann, A.; Steinbrecher, J.; Tranos, S.; Wiedemann, M.

1996-08-01

Biogenic hydrocarbons are known to act as important precursors in tropospheric photochemical ozone formation. Large uncertainties exist about the composition of the mix of volatile organic compounds, emitted by various plant species and the respective emission rates. The emission and deposition behavior of C{sub 6} to C{sub 12} volatile organic compounds (VOC) in Norway spruce forests, oak/pine forests, grassland and the Mediterranean Garigue were studied in detail. The cuvette technique was used to study the emission form the soil, trunks and twigs. The gradient method and the REA-technique were used to obtain canopy fluxes. Among the investigated ecosystems, forests and the Mediterranean Garigue were strong monoterpene emitters, grassland emitted negligible amounts of VOC. Tall forests may act as a sink for anthropogenic hydrocarbons. In a dense Norway spruce forests the contribution of the soil to the total canopy emission was small, the fraction of the steam region may range from 1 to 64% and is not clear yet. For the upper suncrown, with ca. 80% of the needle surfaces the most important source for isoprene and monoterpenes of a closed canopy, a emission factor for {alpha}-pinene of 636 pmol m{sup -2} total needle surface s{sup -1} (30 C leaf temperature and 1000 {mu}E PAR) was calculated. In contrast to the general opinion the main controlling factors of the {alpha}-pinene emission from Norway spruce twigs and the monoterpene emission from Mediterranean oaks are light and temperature. The results of this research were used to update biogenic VOC emission inventories and a significant improvement was achieved. (orig.) [Deutsch] Biogene Kohlenwasserstoffe sind wichtige Vorlaeufer fuer die photochemische Ozonbildung in der Troposphaere. Ueber die qualitative Zusammensetzung der Emissionen von fluechtigen organischen Verbindungen aus der Vegetation und die Quellenstaerken der verschiedenen Verbindungen bestehen grosse Unsicherheiten. In Fichtenwaeldern, Kiefern

Interfacial electronic structure of C{sub 60}/ZnPc/AZO on photoemission spectroscopy for organic photovoltaic applications

Energy Technology Data Exchange (ETDEWEB)

Heo, Nari; Kim, Yoonsu; Jung, Yunwoo; Cheon, Suyoung; Cho, Soohaeng [Department of Physics, Yonsei University, Wonju 220-710 (Korea, Republic of); Cho, Sang Wan, E-mail: dio8027@yonsei.ac.kr [Department of Physics, Yonsei University, Wonju 220-710 (Korea, Republic of); Park, Soohyung; Yi, Yeonjin [Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749 (Korea, Republic of); Smith, Kevin E. [Department of Physics, Boston University, 590 Commonwealth Ave, Boston, MA 02215 (United States)

2016-10-20

Highlights: • The electronic structure of a bilayer on AZO has been evaluated by UPS and XPS. • The energy difference between the ZnPc HOMO and the C{sub 60} LUMO was determined. • The result is discussed in terms of the work function and resistivity of each TCO. - Abstract: The interfacial electronic structure of a bilayer of fullerene (C{sub 60}) and zinc phthalocyanine (ZnPc) grown on aluminum-doped zinc oxide (AZO) substrates has been evaluated by X-ray and ultraviolet photoemission spectroscopy. The energy difference between the highest occupied molecular orbital (HOMO) level of the ZnPc layer and the lowest unoccupied molecular orbital (LUMO) level of the C{sub 60} layer (E{sup D}{sub HOMO} − E{sup A}{sub LUMO}) was determined and compared to that grown on an indium tin oxide (ITO) substrate. The E{sup D}{sub HOMO} − E{sup A}{sub LUMO} value of the heterojunction on AZO was 1.4 eV, while that on ITO was 1.1 eV. This result is discussed in terms of the differences of the work function and resistivity of each transparent conductive oxide. We also obtained complete energy level diagrams of C{sub 60}/ZnPc/AZO and C{sub 60}/ZnPc/ITO.

Molecular dynamics investigations on the interfacial energy and adhesive strength between C{sub 60}-filled carbon nanotubes and metallic surface

Energy Technology Data Exchange (ETDEWEB)

Kuo, Jenn-Kun [Department of Greenergy, National University of Tainan, Tainan 70005, Taiwan (China); Huang, Pei-Hsing, E-mail: phh@mail.npust.edu.tw [Department of Mechanical Engineering, National Pingtung University of Science and Technology, Pingtung 912, Taiwan (China); Wu, Wei-Te; Hsu, Yi-Cheng [Department of Biomechatronics Engineering, National Pingtung University of Science and Technology, Pingtung 912, Taiwan (China)

2014-01-15

The mechanical and adhesive properties of C{sub 60}@(10,10) carbon nanopeapods (CNPs) adhering to gold surfaces are investigated by atomistic simulations. The effects of C{sub 60} fill density, tube length, surrounding temperature, and peeling velocity on the adhesion behavior are studied. Results show that the interfacial binding energy of CNPs (which depends on the C{sub 60} fill density and temperature) is 2.0∼4.4% higher than that of (10,10) single-walled CNTs and 3.4∼4.7% lower than that of (5,5)@(10,10) double-walled CNTs (DWCNTs). Despite their lower interfacial binding energy, CNPs have a higher adhesive strength than that of DWCNTs (1.53 nN vs. 1.4 nN). Distinct from the inner tubes of DWCNTs, which have continuum mechanical properties, the discrete C{sub 60} molecules that fill CNPs exhibit unique composite mechanical properties, with high flexibility and bend-buckling resistance. The bend-buckling forces for CNPs filled with a low/medium fill density of C{sub 60} are approximately constant. When the fill density is 1 C{sub 60} molecule per nanometer length, the bend-buckling force dramatically increases. - Highlights: • Adhesion and peeling behaviors of CNPs on metallic substrates are investigated. • Effects of C60 density, CNP length, temperature, and peeling velocity are studied. • CNPs have a higher adhesive strength than that of DWCNTs (1.53 nN vs. 1.4 nN). • Discrete C{sub 60} molecules that fill CNPs exhibit unique composite mechanical properties.

Mass exchange during rectification of multicomponent mixtures of aromatic C/sub 9/ hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Kutsarov, R; Palichev, T; Tasev, Zh

1978-01-01

The effectiveness is determined of separating a multicomponent aromatic hydrocarbon (ArU) mixture into binary ones relative to the composition of the initial mixture. The study is conducted in mixtures of ArU which contain: C/sub 8/ ArU, isopropylbenzene, n-propylbenzene, ethyloluene, 1,3,5-trimetylbenzene, 1,2,4-trimethylbenzene, 1,2,3-trimethylbenzene and C/sub 10/ ArU. The total content of the C/sub 8/ and C/sub 10/ ArU is less than 2%. The constants of the phase equilibrium of the components are obtained through experiments or are calculated through the Chao-Sider method. The separation of the multicomponent mixture was conducted in periodic, automated rectification column 30 mm in diameter, filled with a steel spiral with a free volume of 0.818 m/sup 3//m/sup 3/ and a specific surface of 0.785 m/sup 2//m/sup 3/ and an effective headpiece height of 1.5 m. The temperature of the housing was maintained with a precision of 0.5/sup 0/, the speed of vapors was maintained constant (0.231 m/sec) through regulating the pressure differential between the top and bottom with a precision of 0.5 mm of mercury. After reaching a stationary mode, samples of the distillate and the sediment were taken and were analyzed chromatographically with a precision of 0.25%. Five distillations of the multicomponent mixtures of various make up were conducted and the distillates and sediments were analyzed. The obtained data are graphically presented.

Heat and Mass Transfer during Solid-Liquid Phase Transition of n-Alkanes in the C{sub 16} to C{sub 19} Range

Energy Technology Data Exchange (ETDEWEB)

Holmen, Rune

2002-07-01

The main goal of this project has been to study heat and mass transfer during solid-liquid phase transition of n-alkanes in the in the C{sub 16} to C{sub 19} range. Phase transitions of both mixtures and pure components have been investigated. All experiments and simulations have been performed without any convection. Thermal conductivities have been determined at the melting point for solid and liquid unbranched alkanes ranging from C{sub 16} to C{sub 19}. An assessment of the error of the method has been performed. The measurements of solid conductivities are in accordance with measurements reported previously and confirm the applicability of the method. Liquid conductivities are higher than extrapolated values from the literature. The enhanced conductivity is believed to be caused by structural changes close to the melting point which is not taken into account when extrapolating values from the literature. Experiments have been performed for the purpose of investigating the freezing of mixtures of n-alkanes in the C{sub 16}-C{sub 19} range. The positions of the solid-liquid interfaces have been measured as freezing occurred. Calculations of the ratio of liquid and solid conductivities show that the solid structure of mixtures of the investigated n-alkanes is predominantly in a rotator structure at the temperatures investigated. There are indications of a transformation into an orthorhombic structure at lower temperatures. The temperatures on the solid-liquid interface have been measured, and compared with calculated values from chapter 4. The temperature of the interface is represented better by the measured interfacial temperatures than by the calculated interfacial temperatures. The experimental results indicate that the diffusion of heat is the limiting mechanism of phase transition. This result in a homogeneous liquid composition. A numerical model has been developed in order to simulate the experimental freezing of mixtures. The model represents the results

On the 'near to minimal' canonical realizations of the Lie algebra Csub(n)

International Nuclear Information System (INIS)

Havlicek, M.; Lassner, W.

1975-01-01

It is proved that canonical realizations of the Lie algebra Csub(n) in the quotient division ring Dsub(2(2n-2)) of the Weyl algebra Wsub(2(2n-2)) in 2n-2 quantum canonical pairs are, in a definite sense, related to the standard minimal one in Dsub(2n) contains Dsub(2(2n-2)). Further, in any realization of Csub(n) in Wsub(2(2n-1)) all Casimir operators are realized by multiples of identity element

Energy level alignment at C{sub 60}/DTDCTB/PEDOT:PSS interfaces in organic photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Yoo, Jisu; Jung, Kwanwook; Jeong, Junkyeong; Hyun, Gyeongho [Institute of Physics and Applied Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722 (Korea, Republic of); Lee, Hyunbok, E-mail: hyunbok@kangwon.ac.kr [Department of Physics, Kangwon National University, Chuncheon-si, Gangwon-do 24341 (Korea, Republic of); Yi, Yeonjin, E-mail: yeonjin@yonsei.ac.kr [Institute of Physics and Applied Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722 (Korea, Republic of)

2017-04-30

Highlights: • The interfacial energy level alignment of C{sub 60}/DTDCTB/PEDOT:PSS was determined via in situ UPS and IPES measurements. • A large photovoltaic gap of 1.30 eV was evaluated between the DTDCTB donor and C{sub 60} acceptor. • A low hole extraction barrier of 0.42 eV from DTDCTB to PEDOT:PSS was evaluated. • The excellent electronic properties of DTDCTB with a narrow band gap were the source of its high OPV power conversion efficiencies. - Abstract: The electronic structure of a narrow band gap small molecule ditolylaminothienyl–benzothiadiazole–dicyanovinylene (DTDCTB), possessing a donor-acceptor-acceptor configuration, was investigated with regard to its application as an efficient donor material in organic photovoltaics (OPVs). The interfacial orbital alignment of C{sub 60}/DTDCTB/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was determined using in situ ultraviolet photoelectron and inverse photoelectron spectroscopic methods. The ionization energy and electron affinity values of DTDCTB were measured to be 5.27 eV and 3.65 eV, respectively, and thus a very small transport gap of 1.62 eV was evaluated. Large band bending of DTDCTB on PEDOT:PSS was observed, resulting in a low hole extraction barrier. Additionally, the photovoltaic gap between the highest occupied molecular orbital level of the DTDCTB donor and the lowest unoccupied molecular orbital level of the C{sub 60} acceptor was estimated to be 1.30 eV, which is known to be the theoretical maximum open-circuit voltage in OPVs employing the C{sub 60}/DTDCTB active layer. The unique electronic structures of DTDCTB contributed toward the recently reported excellent power conversion efficiencies of OPVs containing a DTDCTB donor material.

Possibility of gas sensor based on C{sub 20} molecular devices

Energy Technology Data Exchange (ETDEWEB)

Zhao, Wenkai [School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025 (China); Yang, Chuanlu, E-mail: yangchuanlu@126.com [School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025 (China); Zou, Dongqing [School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Sun, Zhaopeng [School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025 (China); Ji, Guomin [Electrical and Computer Engineering, The University of Oklahoma, Norman, Tulsa, OK 74078 (United States)

2017-06-09

We theoretically investigate the possibility of diatomic gas detection (NO, CO, O{sub 2}) by making use of the transport properties of the C{sub 20} molecular junctions. The calculations are performed by using nonequilibrium Green's function (NEGF) formalism in combination with density functional theory (DFT). In this work, we systematically study the most stable adsorption structural configurations, adsorption energy, and the transport properties on C{sub 20} molecular junctions with these diatomic gas molecules. It is found that NO and O{sub 2} gas molecule can be detected selectively. We suggest its possibility of nanosensors for highly sensitive and selective based on C{sub 20} molecular junction systems. - Highlights: • The most favorable adsorption site is investigated. • The mechanism of gas sensors is revealed. • NO and O{sub 2} gas molecules can be detected by C{sub 20} selectively.

Optical and magneto-optical properties of the electron-doped and hole-doped C{sub 82} crystal

Energy Technology Data Exchange (ETDEWEB)

Rostampour, E., E-mail: el_rostampour@yahoo.com [Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Koohi, A. [Plasma Physics and Nuclear Fusion Research School, Nuclear Science and Technology Research Institute, AEOI, Tehran (Iran, Islamic Republic of)

2015-01-15

The optical and magnetic properties of the doped C{sub 82} crystal have been investigated by Su–Schrieffer–Heeger (SSH) model, which is based on the Ewald method. When the C{sub 82} molecule is doped with one electron (or hole), a single electron is remained in the energy level that affects the optical and magnetic properties of the C{sub 82} crystal. The lattice and electronic structures of C{sub 82} changed with doping electron (or hole) in the molecule of C{sub 82}. Therefore, polarons are predicted in doped fullerenes. The obtained results showed that the dielectric tensor of the C{sub 82} crystal increased with doping electron (or hole) in the molecule of C{sub 82}. The spectral shapes of the dielectric tensor, circular dichroism and birefringence coefficient of the C{sub 82} crystal turn out to be determined mainly by the geometrical distributions of the pentagons in the fullerene structures.

Effects of C{sub 60} nanoparticle exposure on earthworms (Lumbricus rubellus) and implications for population dynamics

Energy Technology Data Exchange (ETDEWEB)

Ploeg, M.J.C. van der, E-mail: merel.vanderploeg@wur.n [Alterra, Wageningen UR, Droevendaalssesteeg 3, 6700 AA, Wageningen (Netherlands); Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE, Wageningen (Netherlands); Baveco, J.M.; Hout, A. van der [Alterra, Wageningen UR, Droevendaalssesteeg 3, 6700 AA, Wageningen (Netherlands); Bakker, R. [RIKILT, Wageningen UR, Akkermaalsbos 2, 6708 WB, Wageningen (Netherlands); Rietjens, I.M.C.M. [Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE, Wageningen (Netherlands); Brink, N.W. van den [Alterra, Wageningen UR, Droevendaalssesteeg 3, 6700 AA, Wageningen (Netherlands)

2011-01-15

Effects of C{sub 60} nanoparticles (nominal concentrations 0, 15.4 and 154 mg/kg soil) on mortality, growth and reproduction of Lumbricus rubellus earthworms were assessed. C{sub 60} exposure had a significant effect on cocoon production, juvenile growth rate and mortality. These endpoints were used to model effects on the population level. This demonstrated reduced population growth rate with increasing C{sub 60} concentrations. Furthermore, a shift in stage structure was shown for C{sub 60} exposed populations, i.e. a larger proportion of juveniles. This result implies that the lower juvenile growth rate due to exposure to C{sub 60} resulted in a larger proportion of juveniles, despite increased mortality among juveniles. Overall, this study indicates that C{sub 60} exposure may seriously affect earthworm populations. Furthermore, it was demonstrated that juveniles were more sensitive to C{sub 60} exposure than adults. - C{sub 60} nanoparticle exposure can affect Lumbricus rubellus populations.

Time-resolved x-ray diffraction measurement of C{sub 60} under high pressure and temperature using synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Horikawa, T [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Suito, K [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Kobayashi, M [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Onodera, A [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan)

2002-11-11

C{sub 60} has been studied by means of time-resolved x-ray diffraction measurements using synchrotron radiation. Diffraction patterns were recorded at intervals of 1-10 min for samples under high pressure (12.5 and 14.3 GPa) and high temperature (up to 800 deg. C) for, at the longest, 3 h. Time, pressure, and temperature dependences of the C{sub 60} structure are presented and the relevance to the hardness of materials derived from C{sub 60} is discussed.

Panicum milioides, a Graminease plant having Kranz leaf anatomy without C/sub 4/-photosynthesis

Energy Technology Data Exchange (ETDEWEB)

Kanai, R; Kashiwagi, M [Saitama Univ., Urawa (Japan). Faculty of Science and Engineering

1975-08-01

Light and electron microscopic observations of the leaf tissue of Panicum milioides showed that bundle sheath cell contained a substanital number of chloroplasts and other organelles. The radial arrangement of chlorenchymatous bundle sheath cells, designated as Kranz leaf anatomy, has been considered to be specific to C/sub 4/ plants. However, photosynthetic /sup 14/CO/sub 2/ fixation and /sup 14/CO/sub 2/ pulse-and-chase experiments revealed that the reductive pentosephosphate pathway was the main route operating in leaves of p. milioides. The interveinal distance of the leaves was intermediate between C/sub 3/ and C/sub 4/ Gramineae species. These results indicate that P. milioides is a natural plant species having characteristics intermediate between C/sub 3/ and C/sub 4/ types.

What is the Impact of Utility Demand Charges on a DCFC host

International Nuclear Information System (INIS)

Francfort, James Edward

2015-01-01

The PEV Electric Vehicle Supply Equipment (EVSE) delivered by The EV Project included both AC Level 2 and DCFC units. Over 100 of these dual-port Blink DC fast chargers were deployed by The EV Project. These DCFCs were installed in workplaces and in publicly accessible locations near traffic hubs, retail centers, parking lots, restaurants, and similar locations. The Blink DCFC is capable of charging at power up to 60 kW. Its dual-port design sequences the charge from one port to the other, delivering power to only one of two vehicles connected at a time. The actual power delivered through a port is determined by the PEV's on-board battery management system (BMS). Both the power and the total energy used to recharge a PEV can represent a significant cost for the charging site host. Many electric utilities impose fees for power demand as part of their commercial rate structure. The demand charge incurred by a customer is related to the peak power used during a monthly billing cycle. This is in contrast to the cumulative total energy usage that is the more familiar utility charge seen for most residential services. A demand charge is typically assessed for the highest average power over any 15 minute interval during the monthly billing cycle. One objective of The EV Project was to identify and elucidate the motivations and barriers to potential DCFC site hosts. The application of electric utility demand charges is one such potential barrier. This subject was introduced in the paper: DC Fast Charge - Demand Charge Reduction1. It discussed demand charge impact in general terms in order to focus on potential mitigation actions. This paper identifies specific cases in order to quantify the impact of demand charges on EV Project DCFC hosts.

What is the Impact of Utility Demand Charges on a DCFC host

Energy Technology Data Exchange (ETDEWEB)

Francfort, James Edward [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-06-01

The PEV Electric Vehicle Supply Equipment (EVSE) delivered by The EV Project included both AC Level 2 and DCFC units. Over 100 of these dual-port Blink DC fast chargers were deployed by The EV Project. These DCFCs were installed in workplaces and in publicly accessible locations near traffic hubs, retail centers, parking lots, restaurants, and similar locations. The Blink DCFC is capable of charging at power up to 60 kW. Its dual-port design sequences the charge from one port to the other, delivering power to only one of two vehicles connected at a time. The actual power delivered through a port is determined by the PEV’s on-board battery management system (BMS). Both the power and the total energy used to recharge a PEV can represent a significant cost for the charging site host. Many electric utilities impose fees for power demand as part of their commercial rate structure. The demand charge incurred by a customer is related to the peak power used during a monthly billing cycle. This is in contrast to the cumulative total energy usage that is the more familiar utility charge seen for most residential services. A demand charge is typically assessed for the highest average power over any 15 minute interval during the monthly billing cycle. One objective of The EV Project was to identify and elucidate the motivations and barriers to potential DCFC site hosts. The application of electric utility demand charges is one such potential barrier. This subject was introduced in the paper: DC Fast Charge - Demand Charge Reduction1. It discussed demand charge impact in general terms in order to focus on potential mitigation actions. This paper identifies specific cases in order to quantify the impact of demand charges on EV Project DCFC hosts.

Tribomechanical behavior of B{sub 4}C{sub p} reinforced Al 359 composites

Energy Technology Data Exchange (ETDEWEB)

Ramasamy, Deivasigamani; Rathanasamy, Rajasekar [Kongu Engineering College, Tamil Nadu (India). Dept. of Mechanical Engineering; Subramanian, Mohan Kumar; Kaliyannan, Gobinath Velu [PAAVAI Engineering College, Tamil Nadu (India). Dept. of Mechatronics Engineering; Palaniappan, Sathish Kumar [Indian Institute of Technology, Kharagpur, West Bengal (India); Durairaj, Jayanth

2017-03-01

n the present investigation, the influence of B{sub 4}C{sub p} particles on the mechanical and tribological behavior of Al 359 composites has been studied. B{sub 4}C{sub p} particle reinforced Al 359 composite samples were prepared by stir casting process. Hardness, tensile strength and wear behavior of the composites were studied and compared with a control specimen. Hardness of B{sub 4}C{sub p} particles reinforced Al 359 matrix increases compared to base matrix due to the presence of the ceramic phase. Coefficient of friction considerably increases with up to 20 wt.-% addition of B{sub 4}C{sub p} in base matrix. Specimens were subjected to wear tests under different load conditions and the following five different wear mechanisms such as wear groove, abrasion, delamination, oxidation and plastic deformation were evaluated. The abrasion results prove the increase in wear resistance of B{sub 4}C{sub p} reinforced composites compared to a control specimen.

Structural organization of C{sub 60} fullerene, doxorubicin, and their complex in physiological solution as promising antitumor agents

Energy Technology Data Exchange (ETDEWEB)

Prylutskyy, Yu. I. [Taras Shevchenko National University of Kyiv (Ukraine); Evstigneev, M. P., E-mail: max-evstigneev@mail.ru [Belgorod State University, Department of Biology and Chemistry (Russian Federation); Cherepanov, V. V. [Institute of Physics of NAS of Ukraine (Ukraine); Kyzyma, O. A.; Bulavin, L. A.; Davidenko, N. A. [Taras Shevchenko National University of Kyiv (Ukraine); Scharff, P. [Ilmenau University of Technology (Germany)

2015-01-15

Specific features of structural self-organization of C{sub 60} fullerene (1 nm size range), antitumor antibiotic doxorubicin (Dox) and their complex in physiological solution (0.9 % NaCl) have been investigated by means of atomic-force microscopy, dynamic light scattering, and small-angle X-ray scattering. Significant ordering of the mixed system, C{sub 60} + Dox, was observed, suggesting the complexation between these drugs, and giving insight into the mechanism of enhancement of Dox antitumor effect on simultaneous administration with C{sub 60} fullerene.

A facile synthesis of C{sub 60}-organosilicon hybrid polymers: Considering their tunable optical properties for spin-on-silicon hardmask materials

Energy Technology Data Exchange (ETDEWEB)

Choi, Jin-Kyu; Dao, Tung Duy; Kim, Ye-Seul; Jeong, Hyun-Dam, E-mail: hdjeong@chonnam.ac.kr

2016-09-15

Organic-inorganic hybrid materials with high refractive index have attracted considerable attention for many optoelectronic applications, including spin-on-type hardmask for ArF lithography (193 nm). In this study, we demonstrate the synthesis of a C{sub 60}-embedded organosilicon hybrid polymer, C{sub 60}-embedded poly-xylene-hexamethyltrisiloxane hybrid (C{sub 60}-PXS), of tunable optical properties. C{sub 60} was covalently bonded to the PXS backbone through Pt-catalyzed hydrosilylation, in which the PXS was formed possibly by unexpected transition metal-catalyzed benzylic C−H silylation and oxygenation of the o-xylene. The C{sub 60}-PXS thin films fabricated using a spin-coating method showed much higher refractive index by 5–22% according to the curing temperatures, than the PXS thin films containing no C{sub 60}. In particular, the C{sub 60}-PXS thin film cured at 350 °C showed the refractive index (n) and extinction coefficient (k) at 193 nm to be 1.61 and 0.29 that are very close to the optimum values for the Si-hardmask. This implies the high applicability of the C{sub 60}-embedded organosilicon hybrid polymer, C{sub 60}-PXS, for the spin-on Si-hardmask in ArF lithography. - Highlights: • A facile synthetic route for C{sub 60}-embedded organosilicon hybrid polymer was presented. • The hybrid polymer showed much higher refractive index than the polymer without C{sub 60}. • The hybrid polymer is highly applicable for Si-hardmask in terms of optical properties. • It is believed that the properties of the hybrid polymer can be further optimized.

Textural and mechanical characterization of C-S-H gels from hydration of synthetic T1-C{sub 3}S, {beta}-C{sub 2}S and their blends; Caracterizacion textural y mecanica de geles C-S-H formados en la hidratacion de muestras sinteticas T1-C{sub 3}S, {beta}-C{sub 2}S y sus mezclas

Energy Technology Data Exchange (ETDEWEB)

Goni, S.; Guerrero, A.; Puertas, F.; Hernandez, M. S.; Palacios, M.; Dolado, J. S.; Zhu, W.; Howind, T.

2011-07-01

The textural and mechanical characterization of C-S-H gels formed from the hydration of pure T1-C{sub 3}S, {beta}-C{sub 2}S and their blends are studied by Nitrogen sorption and nano indentation experiments. The surface area and nano porosity of C-S-H gels formed from the hydration of {beta}-C{sub 2}S and the 30-70 (T1-C{sub 3}S and {beta}-C{sub 2}S mixture) are higher than those from hydration of T1-C{sub 3}S, and 70-30, with the difference decreasing with hydration age. Such changes are well supported by findings of nano indentation study, which shows the greater relative volume of C-S-H phases with lower densities in the {beta}-C{sub 2}S and the 30-70 pastes. With the increase in hydration age, the relative volume of C-S-H phases with higher densities increased at the expenses of those with lower density. Important quantitative correlations were found among these textural characteristics and the mean chain length, determined from {sup 2}9Si magic-angle-spinning (MAS) NMR, of the C-S-H gels. (Author) 36 refs.

Water Assisted Growth of C>60 Rods and Tubes by Liquid–Liquid Interfacial Precipitation Method

Directory of Open Access Journals (Sweden)

Cheuk-Wai Tai

2012-06-01

Full Text Available C>60 nanorods with hexagonal cross sections are grown using a static liquid–liquid interfacial precipitation method in a system of C>60/m-dichlorobenzene solution and ethanol. Adding water to the ethanol phase leads instead to C>60 tubes where both length and diameter of the C>60 tubes can be controlled by the water content in the ethanol. Based on our observations we find that the diameter of the rods/tubes strongly depends on the nucleation step. We propose a liquid-liquid interface growth model of C>60 rods and tubes based on the diffusion rate of the good C>60 containing solvent into the poor solvent as well as on the size of the crystal seeds formed at the interface between the two solvents. The grown rods and tubes exhibit a hexagonal solvate crystal structure with m-dichlorobenzene solvent molecules incorporated into the crystal structure, independent of the water content. An annealing step at 200 °C at a pressure < 1 kPa transforms the grown structures into a solvent-free face centered cubic structure. Both the hexagonal and the face centered cubic structures are very stable and neither morphology nor structure shows any signs of degradation after three months of storage.

Anharmonic rovibrational calculations of singlet cyclic C{sub 4} using a new ab initio potential and a quartic force field

Energy Technology Data Exchange (ETDEWEB)

Wang, Xiaohong; Bowman, Joel M., E-mail: jmbowma@emory.edu [Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322 (United States); Huang, Xinchuan [SETI Institute, 189 Bernardo Ave, Suite 100, Mountain View, California 94043 (United States); Lee, Timothy J., E-mail: Timothy.J.Lee@nasa.gov [MS 245-1, NASA Ames Research Center, Mofffett Field, California 94035 (United States)

2013-12-14

We report a CCSD(T)/cc-pCV5Z quartic force field (QFF) and a semi-global CCSD(T)-F12b/aug-cc-pVTZ potential energy surface (PES) for singlet, cyclic C{sub 4}. Vibrational fundamentals, combinations, and overtones are obtained using vibrational second-order perturbation theory (VPT2) and the vibrational configuration-interaction (VCI) approach. Agreement is within 10 cm{sup −1} between the VCI calculated fundamentals on the QFF and PES using the MULTIMODE (MM) program, and VPT2 and VCI results agree for the fundamentals. The agreement between VPT2-QFF and MM-QFF results is also good for the C{sub 4} combinations and overtones. The J = 1 and J = 2 rovibrational energies are reported from both VCI (MM) on the PES and VPT2 on the QFF calculations. The spectroscopic constants of {sup 12}C{sub 4} and two C{sub 2v}-symmetry, single {sup 13}C-substituted isotopologues are presented, which may help identification of cyclic C{sub 4} in future experimental analyses or astronomical observations.

Dramatic distortion of the 4d giant resonance by the C{sub 60} fullerene shell

Energy Technology Data Exchange (ETDEWEB)

Amusia, M Ya [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel); Baltenkov, A S [Arifov Institute of Electronics, Akademgorodok, 700125 Tashkent (Uzbekistan); Chernysheva, L V [A F Ioffe Physical-Technical Institute, St Petersburg 194021 (Russian Federation); Felfli, Z [Department of Physics and Center for Theoretical Studies of Physical Systems, Clark Atlanta University, Atlanta, GA 30314 (United States); Msezane, A Z [Department of Physics and Center for Theoretical Studies of Physical Systems, Clark Atlanta University, Atlanta, GA 30314 (United States)

2005-05-28

The photoionization cross section for the endohedral Xe at C{sub 60} atom is investigated within the framework of representing the C{sub 60} by a delta-type potential. Results demonstrate that in Xe at C{sub 60}, the 4d giant resonance is distorted significantly when compared with that of the isolated Xe atom. The reflection of the photoelectron waves by the C{sub 60} causes strong oscillations in the photoionization cross section resulting in the replacement of the Xe 4d giant resonance by four prominent peaks. The approximation of C{sub 60} by an infinitely thin real potential preserves reasonably well the sum rule for the 4d electrons but modifies the dipole polarizability of the 4d shell. (letter to the editor)

Host immunostimulation and substrate utilization of the gut symbiont Akkermansia muciniphila

NARCIS (Netherlands)

Ottman, N.A.

2015-01-01

Host immunostimulation and substrate utilization of the gut symbiont Akkermansia muciniphila

Noora A. Ottman

The human gastrointestinal tract is colonized by a complex community of micro-organisms, the gut microbiota. The majority of these

The dependence of electronic transport on compressive deformation of C{sub 60} molecule

Energy Technology Data Exchange (ETDEWEB)

Li, H. [Key Lab of Liquid Structure and Heredity of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University (China)], E-mail: lihuilmy@hotmail.com; Zhang, X.Q. [Physics Department, Ocean University of China, Qingdao (China)

2008-06-02

The dependence of electronic transport on compressive deformation of C{sub 60} molecule is studied theoretically in this work. Brenner's 'second generation' empirical potential is used to describe the many-body short-range interatomic interactions for C{sub 60} in the molecular dynamics simulations. Our results demonstrate that C{sub 60} can be compressed up to a strain {epsilon}=0.31 before collapsing. Electronic transport under an applied bias is calculated by using a self-consistent field approach coupled with non-equilibrium Green's function (NEGF) formalism. The transmission probability, conductance gap, and conductance spectrum are found to be sensitive to the compression. The peak value of conductance decreases with the increase of strain until the C{sub 60} is compressed up to a strain {epsilon}=0.31.

Influence of impurities on the density of states at the fermi level in the c(6x4)-C{sub 60}/Ag(1 0 0) two-dimensional superstructure

Energy Technology Data Exchange (ETDEWEB)

Vobornik, I. E-mail: ivana.vobornik@elettra.trieste.it; Avramova, I.; Giovanelli, L.; Panaccione, G.; Fujii, J.; Vobornik, S.; Cepek, C.; Sancrottti, M.; Rossi, G

2003-01-01

A number of recent results indicate that C{sub 60} films can superconduct at considerably high temperatures. The response of a material to impurities can give an information about its superconducting properties when more conventional methods for spotting superconductivity are difficult to apply. While magnetic impurities act as strong Cooper pair breakers in conventional superconductors, nonmagnetic impurities have none or negligible effect. We investigated the influence of magnetic and nonmagnetic impurities on the electronic structure of one monolayer C{sub 60} on Ag(1 0 0). Preliminary results show that the gap persists in the presence of nonmagnetic Au but it is completely suppressed in the presence of magnetic Fe, as expected for a superconductor. This result gives a support for the possible superconducting scenario in one monolayer C{sub 60} on Ag(1 0 0) and certainly requires additional experiments to be performed to assure the superconducting character of the film.

New developments in the Csub(N) method

International Nuclear Information System (INIS)

Grandjean, Paul; Kavenoky, Alain.

1975-01-01

The most recent developments of the Csub(N) method used for solving transport equations are presented: treatment of the Rayleigh scattering kernel in plane geometry and of the cylindrical problems with an isotropic scattering law [fr

Biodistribution and tumor uptake of C{sub 60}(OH){sub x} in mice

Energy Technology Data Exchange (ETDEWEB)

Zhiqiang, Ji; Sun Hongfang, E-mail: shf@pku.edu.cn; Haifang, Wang; Qunying, Xie; Yuangfang, Liu [Peking University, Department of Chemical Biology, College of Chemistry and Molecular Engineering (China); Zheng, Wang [Chinese Academy of Medical Sciences, Cancer Institute (China)

2006-02-15

Radiolabeling of fullerol, {sup 125}I-C{sub 60}(OH){sub x}, was performed by the traditional chloramine-T method. The C-I covalent bond in I-C{sub 60}(OH){sub x} was characterized by X-ray photoelectron spectroscopy (XPS) that was sufficiently stable for in vivo study. Laser light scattering spectroscopy clearly showed that C{sub 60}(OH){sub x} aggregated to large nanoparticle clumps with a wide range of distribution. The clumps formed were also visualized by transmission electron microscope (TEM). We examined the biodistribution and tumor uptake of C{sub 60}(OH){sub x} in five mouse bearing tumor models, including mouse H22 hepatocarcinoma, human lung giantcellcarcinoma PD, human colon cancer HCT-8, human gastric cancer MGC803, and human OS732 osteosarcoma. The accumulation ratios of {sup 125}I-C{sub 60}(OH){sub x} in mouse H22 hepatocarcinoma to that in normal muscle tissue (T/N) and blood (T/B) at 1, 6, 24 and 72 h, reveal that {sup 125}I-C{sub 60}(OH){sub x} gradually accumulates in H22 tumor, and retains for a quite long period (e.g., T/N 3.41, T/B 3.94 at 24 h). For the other four tumor models, the T/N ratio at 24 h ranges within 1.21-6.26, while the T/B ratio ranges between 1.23 and 4.73. The accumulation of C{sub 60}(OH){sub x} in tumor is mostly due to the enhanced permeability and retention effect (EPR) and the phagocytosis of mononuclear phagocytes. Hence, C{sub 60}(OH){sub x} might serve as a photosensitizer in the photodynamic therapy of some kinds of tumor.

Structural and electronic properties of La C[sub 82

Energy Technology Data Exchange (ETDEWEB)

Laasonen, K.; Andreoni, W.; Parrinello, M. (Zurich Research Lab., Rueschlikon (Switzerland))

1992-12-18

The structural and electronic properties of the La C[sub 82] fullerene have been investigated by means of the Car-Parrinello method, which is based on the local density approximation of the density functional theory. The topological arrangement of the C[sub 82] cage was assumed to be a C[sub 3v] symmetry isomer. Three configurations were considered, one with the lanthanum atom at the center of the cluster, one with it along the threefold axis, and one with it at a low-symmetry, highly coordinated site. The structure was fully relaxed and it was found that the last of these configurations is energetically preferred. In this position, the lanthanum atom is nearly in a La[sup 3+] state and the unpaired electron is somewhat delocalized on the cage, in agreement with available experimental data. This arrangement suggests that the chemical shifts of the 5s and 5p lanthanum states can be used as a structural probe and as a way of further validating this picture. It is argued that this conclusion is not affected by the assumed fullerene structure.

Infrared studies of the evolution of the C{sub i}O{sub i}(Si{sub I}) defect in irradiated Si upon isothermal anneals

Energy Technology Data Exchange (ETDEWEB)

Angeletos, T.; Londos, C. A., E-mail: hlontos@phys.uoa.gr [University of Athens, Solid State Physics Section, Panepistimiopolis Zografos, Athens 157 84 (Greece); Chroneos, A., E-mail: alexander.chroneos@imperial.ac.uk [Faculty of Engineering, Environment and Computing, Coventry University, Priory Street, Coventry CV1 5FB (United Kingdom); Department of Materials, Imperial College London, London SW7 2AZ (United Kingdom)

2016-03-28

Carbon-oxygen-self-interstitial complexes were investigated in silicon by means of Fourier transform infrared spectroscopy. Upon irradiation, the C{sub i}O{sub i} defect (C{sub 3}) forms which for high doses attract self-interstitials (Si{sub I}s) leading to the formation of the C{sub i}O{sub i}(Si{sub I}) defect (C{sub 4}) with two well-known related bands at 939.6 and 1024 cm{sup −1}. The bands are detectable in the spectra both in room temperature (RT) and liquid helium (LH) temperature. Upon annealing at 150 °C, these bands were transformed to three bands at 725, 952, and 973 cm{sup −1}, detectable only at LH temperatures. Upon annealing at 220 °C, these bands were transformed to three bands at 951, 969.5, and 977 cm{sup −1}, detectable both at RT and LH temperatures. Annealing at 280 °C resulted in the transformation of these bands to two new bands at 973 and 1024 cm{sup −1}. The latter bands disappear from the spectra upon annealing at 315 °C without the emergence of other bands in the spectra. Considering reaction kinetics and defect metastability, we developed a model to describe the experimental results. Annealing at 150 °C triggers the capturing of Si{sub I}s by the C{sub 4} defect leading to the formation of the C{sub i}O{sub i}(Si{sub I}){sub 2} complex. The latter structure appears to be bistable: measuring at LH, the defect is in configuration C{sub i}O{sub i}(Si{sub I}){sub 2} giving rise to the bands at 725, 952, and 973 cm{sup −1}, whereas on measurements at RT, the defect converts to another configuration C{sub i}O{sub i}(Si{sub I}){sub 2}{sup *} without detectable bands in the spectra. Possible structures of the two C{sub i}O{sub i}(Si{sub I}){sub 2} configurations are considered and discussed. Upon annealing at 220 °C, additional Si{sub I}s are captured by the C{sub i}O{sub i}(Si{sub I}){sub 2} defect leading to the formation of the C{sub i}O{sub i}(Si{sub I}){sub 3} complex, which in turn on annealing at

Comparative studies on the photosynthesis of higher plants, 4. Further studies on the photosynthetic sugar formation pathway in C/sub 4/-plants

Energy Technology Data Exchange (ETDEWEB)

Imai, H [National Inst. of Agricultural Sciences, Tokyo (Japan); Iwai, Sumio; Yamada, Yoshio

1975-03-01

In this paper, studies were carried out to confirm whether carbon atoms except C-4 of C/sub 4/-compounds were involved in the photosynthetic sugar formation in C/sub 4/ plants. In feeding of uniformly-labeled malate to maize leaves, sugar formation under aerobic conditions was 3 times as large as that under anaerobic conditions. There was no detectable difference in the amount of activity in the sugar formed from ..beta..-carboxyl-labeled malate between aerobic and anaerobic conditions; however. Under anaerobic conditions, sugar was formed from alanine-1-/sup 14/C in maize but not in rice leaves. Sugar formation of this case might have occurred by the direct conversion of pyruvate to sugar via PEP and PGA. From these results, we assume that the following three pathways function cooperatively in the photosynthetic sugar formation in C/sub 4/-plants. 1) One carbon atom at number 4 in C/sub 4/-dicarboxylic acid is transferred to RuDP, resulting in the formation of PGA and this is metabolized into sugar. 2) After transferring C-4 of C/sub 4/-dicarboxylic acid, the remaining C/sub 3/-compound is introduced into the TCA cycle and completely degradated there, and thus-produced CO/sub 2/ is refixed by PEP carboxylase in the mesophyll and metabolized into sugar the same pathway as in atmospheric CO/sub 2/ fixation. 3) The remaining C/sub 3/-compound is directly converted to PEP and then to sugar via PGA.

Interactions to the fifth trophic level: secondary and tertiary parasitoid wasps show extraordinary efficiency in utilizing host resources

NARCIS (Netherlands)

Harvey, J.A.; Wagenaar, R.; Bezemer, T.M.

2009-01-01

1. Parasitoid wasps are highly efficient organisms at utilizing and assimilating limited resources from their hosts. This study explores interactions over three trophic levels, from the third (primary parasitoid) to the fourth (secondary parasitoid) and terminating in the fifth (tertiary

Structural and magnetic properties of Co films on highly textured and randomly oriented C{sub 60} layers

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong-Ok [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Choi, Jun Woo, E-mail: junwoo@kist.re.kr [Center for Spintronics Research, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Lee, Dong Ryeol, E-mail: drlee@ssu.ac.kr [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of)

2016-03-01

The structural and magnetic properties of Co/C{sub 60}/pentacene and Co/C{sub 60} thin film structures were investigated. Atomic force microscopy and x-ray reflectivity analysis show that the presence or absence of a pentacene buffer layer leads to a highly textured or randomly oriented C{sub 60} layer, respectively. A Co film deposited on a randomly oriented C{sub 60} layer penetrates into the C{sub 60} layer when it is deposited at a slow deposition rate. The Co penetration can be minimized, regardless of the Co deposition rate, by growth on a highly textured and nanostructured C{sub 60}/pentacene layer. Vibrating sample magnetometry measurements show that the saturation magnetization of Co/C{sub 60}/pentacene is significantly reduced compared to that of Co/C{sub 60}. On the other hand, the Co penetration does not seem to have an effect on the magnetic properties, suggesting that the structural properties of the Co and C{sub 60} layer, rather than the Co penetration into the organic C{sub 60} layer, are critical to the magnetic properties of the Co/C{sub 60}. - Highlights: • Structural and magnetic properties of metal(Co)-organic(C{sub 60}) interface is studied. • Highly textured C{sub 60} layer was grown on a pentacene buffer layer (C{sub 60}/pentacene). • Co penetration into the C{sub 60} is significantly suppressed in Co/C{sub 60}/pentacene. • The Co magnetization in Co/C{sub 60}/pentacene is reduced than that in Co/C{sub 60}.

On the structural phase transitions of the perovskite-type layer structures (Csub(n)Hsub(2n+1)NH3)2MeCl4

International Nuclear Information System (INIS)

Heger, G.

1978-01-01

The perovskite-type layer compounds (Csub(n)Hsub(2n+1)NH 3 ) 2 MeCl 4 show a variety of different structural modifications. They differ from oneanother by the order and dynamical behaviour of the CH 3 -CH 2 -...-CH 2 -NH 3 chain molecules and the [MeCl 6 ] octahedra layers. These two structural members are coupled together by N-H...Cl hydrogen bonds. According to group theoretical relations the modifications of (Csub(n)Hsub(2n+1)NH 3 ) 2 MeCl 4 were ordered in the scheme of a 'family tree'. Taking (CH 3 NH 3 ) 2 MnCl 4 as an example, various experimental investigations incorporated neutron diffraction are reported. They lead to a sequence of phase transitions. For these phase transitions a model is developed based on the orientations of the CH 3 NH 3 dump-bell molecules and their interactions with the [MnCl 6 ] layers. (orig./HPOE) [de

Geometry and bonding in the ground and lowest triplet state of D{sub 6h} symmetric crenellated edged C{sub 6[3m(m-1)+1]}H{sub 6(2m-1)} (m = 2,..., 6) graphene hydrocarbon molecules

Energy Technology Data Exchange (ETDEWEB)

Philpott, Michael R., E-mail: philpott@imr.edu [Center for Computational Materials Science, Institute of Materials Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, 980-8577 Sendai (Japan); Kawazoe, Yoshiyuki [Center for Computational Materials Science, Institute of Materials Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, 980-8577 Sendai (Japan)

2009-03-30

Ab initio plane wave all valence electron based DFT calculations were used to explore the dichotomy of perimeter vs. interior in the electronic and geometric structure of the D{sub 6h} singlet ground state and D{sub 2h} lowest triplet state of planar graphene hydrocarbon molecules with crenellated (arm chair) edges and the general formula C{sub 6[3m(m-1)+1]} H{sub 6(2m-1)} where m = 2,...,6. The largest molecule C{sub 546}H{sub 66} was 4.78 nm across and contained 2250 valence electrons. These molecules are nominally 'fully benzenoid hydrocarbons'. However with increasing size, the core of central atoms abandoned any fully benzenoid geometry they had in small systems and organized into single layer graphite (graphene) structure. The perimeter atoms of the crenellation adopted a conjugated geometry with unequal bonds and between core and perimeter there were some C{sub 6} rings retaining remnants of aromatic sextet-type properties. Compared to a zigzag edge the crenellated edge conferred stability in all the systems studied as measured by the singlet homo-lumo level gap BG{sub 0} and the singlet-lowest triplet energy gap {Delta}E{sub ST}. For the largest crenellated system (m = 6) BG{sub 0} and {Delta}E{sub ST} were approximately 0.7 eV, larger in value than for similarly sized hexagonal graphenes with zigzag edges. Triplet states were identified for all the molecules in the series and in the case of the m = 2 molecule hexabenzocoronene C{sub 42}H{sub 18}, two conformations with D{sub 2h} symmetry were identified and compared to features on the triplet state potential energy surface of benzene.

Sugar supported H/sub 2/ production and C/sub 2/H/sub 2/ reduction by the cyanobiont Anabaena azollae

Energy Technology Data Exchange (ETDEWEB)

Rozen, A.; Tel-Or, E.

1986-01-01

Sugar supported activities of H/sub 2/ production and C/sub 2/H/sub 2/ reduction were characterized in axenic cell cultures of the cyanobiont Anabaena azollae isolated from the water fern Azolla filiculoides. Fructose was found to be the favoured substrate, enhancing activities in both the light and the dark even at relatively low concentrations of 0.5-1.0 mM. Higher concentrations of sucrose, (10-20mM) also supported H/sub 2/ production and C/sub 2/H/sub 2/ reduction, while glucose was less effective. Levels of H/sub 2/ production were always lower than those of C/sub 2/H/sub 2/ reduction. 13 references.

Perturbative determination of c{sub SW} with Symanzik improved gauge action and stout smearing

Energy Technology Data Exchange (ETDEWEB)

Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics; Perlt, H.; Schiller, A. [Leipzig Univ. (Germany). Inst. fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Dept., Dept. of Mathematical Sciences; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2007-10-15

We determine the improvement factor c{sub SW} in one-loop lattice perturbation theory for the plaquette and Symanzik improved gauge actions. The fermionic action is O(a) clover improved with one-time stout smearing. c{sub SW} is derived from the one-loop correction to the quark-quark-gluon vertex in the off-shell regime. We give a first numerical value for the one-loop contribution to the non gauge-invariant improvement coefficient c{sub NGI} for the quark field using the plaquette action. A discussion of mean field improvement is included. (orig.)

Interaction of protons with the C{sub 60} molecule: calculation of deposited energies and electronic stopping cross sections (v{sub {<=}}5 au)

Energy Technology Data Exchange (ETDEWEB)

Moretto-Capelle, P. [Laboratoire CAR, IRSAMC, UMR 5589 CNRS, Universite Paul Sabatier, Toulouse (France)]. E-mail: pmc@irsamc.ups-tlse.fr; Bordenave-Montesquieu, D.; Rentenier, A.; Bordenave-Montesquieu, A. [Laboratoire CAR, IRSAMC, UMR 5589 CNRS, Universite Paul Sabatier, Toulouse (France)

2001-09-28

The energy deposited by a proton in a C{sub 60} molecule is calculated over a broad collision velocity range from 0.1 to 5 au, using the free-electron gas model of Lindhard and Winther (1964 Mat. Fys. Medd. K Dan. Vidensk. Selsk. 34) and the C{sub 60} electron density distribution calculated by Puska and Nieminen. The energy lost by the proton is maximum near 1.8 au collision velocity in contrast with the saturation found in the low-velocity regime, in the 0.25-0.5 au velocity range, by Kunert and Schmidt. From the impact parameter dependence we deduce the distributions of deposited energies, the averaged energy losses and the C{sub 60} electronic stopping cross sections. It is found that the C{sub 60} molecule behaves as a carbon foil giving very similar absolute stopping cross sections per atom. (author). Letter-to-the-editor.

A 3d-4f complex constructed by the assembly of a cationic template, [Cu(en){sub 2}]{sup 2+}, and a 3D anionic coordination polymer, [Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}(C{sub 5}O{sub 5})(H{sub 2}O){sub 2}]{sup 2-}

Energy Technology Data Exchange (ETDEWEB)

Ke, Szu-Yu; Yeh, Chang-Tsung; Wang, Chih-Chieh [Department of Chemistry, Soochow University, Taipei, Taiwan (China); Lee, Gene-Hsiang [Instrumentation Center, National Taiwan University, Taipei, Taiwan (China); Sheu, Hwo-Shuenn [National Synchrotron Radiation Research Center, Hsinchu, Taiwan (China)

2017-05-18

A three-dimensional (3D) 3d-4f complex, [Cu(en){sub 2}][Sm{sub 2}(C{sub 5}O{sub 5})(C{sub 2}O{sub 4}){sub 3}(H{sub 2}O){sub 2}].8H{sub 2}O (1) (en = ethylenediamine, C{sub 5}O{sub 5}{sup 2-} = dianion of 4,5-dihydroxycyclopent-4-ene-1,2,3-trione), were prepared via the in-situ ring-opening oxidation reaction of croconate in the presence of the template-directed complex, [Cu(en){sub 2}]{sup 2+} cation. The structural characterization determined by X-ray diffraction determination reveals that the 3D anionic coordination polymer of [Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}(C{sub 5}O{sub 5})(H{sub 2}O){sub 2}]{sup 2-} in 1 can be describe in terms of in-plane 2D honeycomb-like [Sm{sub 2}(C{sub 2}O{sub 4}){sub 3}] layered frameworks bridged by oxalate with bis-chelating mode, being mutually interlinked via the bridge of μ{sub 1,2,3,4}-croconate ligands with bis-chelating coordination mode to complete the 3D open framework, which gives rise to 1D channels with pore size of 14.023 x 11.893 Aa (longest atom-atom contact distances) along the b axis. The structure-directing complex, [Cu(en){sub 2}]{sup 2+}, and solvated water molecules are resided into these honeycomb-type hexagonal channels. The thermal stability of 1 was further studied by TGA and in-situ powder X-ray diffraction measurement. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Multiple ionization of C{sub 60} in collisions with 2.33MeV/u O-ions and giant plasmon excitation

Energy Technology Data Exchange (ETDEWEB)

Kelkar, A.H. [Tata Institute of Fundamental Research, Colaba, Mumbai 400 005 (India)]. E-mail: lokesh@tifr.res.in; Kadhane, U. [Tata Institute of Fundamental Research, Colaba, Mumbai 400 005 (India); Misra, D. [Tata Institute of Fundamental Research, Colaba, Mumbai 400 005 (India); Kumar, Ajay [Tata Institute of Fundamental Research, Colaba, Mumbai 400 005 (India); Tribedi, L.C. [Tata Institute of Fundamental Research, Colaba, Mumbai 400 005 (India)

2007-03-15

Single and multiple ionization of C{sub 60} in collisions with fast (v=9.7a.u.) O{sup q+} ions have been studied. Relative cross sections for production of C{sub 60}{sup 1+} to C{sub 60}{sup 4+} have been measured. The intensity ratios of double-to-single ionization agree very well with a model based on giant dipole plasmon resonance (GDPR). Almost linear increasing trend of the yields of single and double ionizations with projectile charge state is well reproduced by the single and double plasmon excitation mechanisms. The observed charge state independence of triple and quadruple ionization is in sharp contrast to the GDPR model.

First-principle calculations on the structural and electronic properties of hard C{sub 11}N{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Li, Dongxu, E-mail: lidongxu@hqu.edu.cn [College of Materials Science and Engineering, Huaqiao University, Xiamen 361021 (China); Shi, Jiancheng; Lai, Mengling; Li, Rongkai [College of Materials Science and Engineering, Huaqiao University, Xiamen 361021 (China); Yu, Dongli [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China)

2014-09-15

A graphite-like C{sub 11}N{sub 4} model was built by stacking graphene and a C{sub 3}N{sub 4} triazine layer and simulated by first principle calculations, which transfers to a diamond-like structure under high pressure. The structural, mechanical, and electronic properties of both materials were calculated. The elastic constants of both materials satisfy the Born-criterion. Furthermore, no imaginary frequencies were observed in phonon calculations. The diamond-like C{sub 11}N{sub 4} is semiconducting and consists of polyhedral and hollow C–N cages. The Vickers hardness of diamond-like C{sub 11}N{sub 4} was calculated to be 58 GPa. The phase transformation from graphite-like to diamond-like C{sub 11}N{sub 4} is proposed to occur at approximately 27.2 GPa based on the pressure-dependent enthalpy.

Determination of c{sub sw} in N{sub f}=3+1 lattice QCD with massive Wilson fermions

Energy Technology Data Exchange (ETDEWEB)

Stollenwerk, Felix

2017-02-07

In order to obtain sensible results from Lattice QCD that may be compared with experiment, extrapolation to the continuum is crucial. The well-established Symanzik improvement program systematically reduces the order of cutoff effects, allowing for better control of the aforementioned errors, as well as larger and thus more affordable lattice spacings. Applied to the Wilson fermion action, it entails the addition of the Sheikholeslami-Wohlert term with the O(a) improvement coefficient c{sub sw}. In this work, a strategy is developed for the non-perturbative determination of c{sub sw} in the theory with N{sub f}=3+1 massive sea quarks. It is embedded in a general, mass-dependent renormalization and improvement scheme, for which we lay the foundations. The improvement condition, formulated by means of the PCAC relation in the Schroedinger Functional, is imposed along a line of constant physics that is designed to be close to the physical mass of the charm quark. The aim of this rather elaborate approach is to avoid large, mass-dependent O(a{sup 2}) effects in future large volume simulations with four dynamical quark species. The numerical results are worked out using the tree-level improved Luescher-Weisz gauge action. Since the gradient flow coupling is employed in the definition of the line of constant physics, its interdependence with the topological charge in regard to critical slowing down and topology freezing is investigated in a supplemental study.

The H{sub 60}Si{sub 6}C{sub 54} heterofullerene as high-capacity hydrogen storage medium

Energy Technology Data Exchange (ETDEWEB)

Yong, Yongliang, E-mail: ylyong@haust.edu.cn [College of Physics and Engineering, Henan University of Science and Technology, Luoyang 471003 (China); Department of Physics, Zhejiang University, Hangzhou 310027 (China); Zhou, Qingxiao; Li, Xiaohong; Lv, Shijie [College of Physics and Engineering, Henan University of Science and Technology, Luoyang 471003 (China)

2016-07-15

With the great success in Si atoms doped C{sub 60} fullerene and the well-established methods for synthesis of hydrogenated carbon fullerenes, this leads naturally to wonder whether Si-doped fullerenes are possible for special applications such as hydrogen storage. Here by using first-principles calculations, we design a novel high-capacity hydrogen storage material, H{sub 60}Si{sub 6}C{sub 54} heterofullerene, and confirm its geometric stability. It is found that the H{sub 60}Si{sub 6}C{sub 54} heterofullerene has a large HOMO-LUMO gap and a high symmetry, indicating it is high chemically stable. Further, our finite temperature simulations indicate that the H{sub 60}Si{sub 6}C{sub 54} heterofullerene is thermally stable at 300 K. H{sub 2} molecules would enter into the cage from the Si-hexagon ring because of lower energy barrier. Through our calculation, a maximum of 21 H{sub 2} molecules can be stored inside the H{sub 60}Si{sub 6}C{sub 54} cage in molecular form, leading to a gravimetric density of 11.11 wt% for 21H{sub 2}@H{sub 60}Si{sub 6}C{sub 54} system, which suggests that the hydrogenated Si{sub 6}C{sub 54} heterofullerene could be suitable as a high-capacity hydrogen storage material.

Ferroelectric response in an achiral non-symmetric bent liquid crystal:C{sub 12}C{sub 10}

Energy Technology Data Exchange (ETDEWEB)

Subrahmanyam, S.V.; Chalapathi, P.V. [Department of Physics, University College of Engineering, Jawaharlal Nehru Technological University Kakinada, Kakinada 533003 (India); Mahabaleshwara, S.; Srinivasulu, M. [Department of Chemistry, Manipal Institute of Technology, Manipal University, Manipal 576104 (India); George, A.K. [Department of Physics, College of Sciences, Sultan Qaboos University, PO Box-36, PC-123, Muscat (Oman); Potukuchi, D.M., E-mail: potukuchidm@yahoo.com [Department of Physics, University College of Engineering, Jawaharlal Nehru Technological University Kakinada, Kakinada 533003 (India)

2014-10-01

An achiral Non-Symmetric Bent Liquid Crystal (BLC) with a Oxadiazole based hetero cyclic central moiety, abbreviated as C{sub 12}C{sub 10} viz., dodecyl[4-{5-(4′-decyloxy)biphenyl-4-yl}-1,2,4-oxadiazol-3-yl]benzoate, exhibiting FerroElectric (FE) response is reported. Product is confirmed by {sup 1}H NMR, {sup 13}C NMR and elemental analysis. Characterization of BLC phases is carried out by Polarized Optical Microscopy (POM), Differential Scanning Calorimetry (DSC), Spontaneous Polarization (P{sub S}) and Low Frequency (10 Hz–10 MHz) Dielectric Relaxation studies. C{sub 12}C{sub 10} exhibits enantiotropic LC SmA, FE B{sub 2}, SmG, SmE phase variance. I–SmA, B{sub 2}–SmG and SmG–SmE transitions are of first order nature. FE B{sub 2} phases exhibits a moderate P{sub S} of ∼80 nC cm{sup −2}. B{sub 2} phase exhibits Curie–Weiss behavior to confirm FE nature. Off-centered low frequency (KHz) dispersion infers a scissor mode and a high frequency (MHz) mode to reflect the distinct time-scale response. Dielectric Dispersion is relatively susceptible in lower frequency KHz region. Arrhenius shift in Relaxation Frequency (f{sub R}) infers higher activation energy (E{sub a}) in non-FE phases for HF mode and lower value for KHz mode. Trends of f{sub R}, dielectric strength Δε, α-parameter and E{sub a} are discussed in view of the data reported in other LC compounds.

Identification of marine methanol-utilizing bacteria

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, M; Iwaki, H; Kouno, K; Inui, T

1980-01-01

A taxonomical study of 65 marine methanol-utilizing bacteria is described. They were Gram-negative, non-spore-forming rods with a polar flagellum and had marine bacterial properties and required vitamin B/sub 12/ for growth. All of them assimilated fructose in addition to C/sub 1/-compounds and produced acid oxidatively from fructose. Twenty-four strains assimilated only C/sub 1/-compounds. They were resistant to penicillin, oxytetracycline and 0/129 substance (Vibrio stat), and tolerant to 12% NaCl. Guanine-cytosine contents of deoxyribonucleic acid in typical strains fell in the range of 43.8 to 47.6%. Other morphological and physiological properties were almost the same as those of terrestrial methanol-utilizers. Bacteria in the first group (41 strains) were facultative methylotrophs and were divided into three subgroups by the assimilation of methylated amines, that is, subgroup I (30 strains) assimilated mono-, di- and tri-methylamine, subgroup II (9 strains) assimilated only mono-methylamine, the bacteria of subgroups I and II were named Alteromonas thalassomethanolica sp. nov. and subgroup III (2 strains) did not assimilate methylated amines, and was tentatively assigned as Alteromonas sp. The second group of bacteria (24 strains) was obligate methylotrophs, named Methylomonas thalassica sp. nov. and was divided into subgroup IV (15 strains) which assimilated mono-, di and tri-methylamine and subgroup V (9 strains) which assimilated mono-methylamine.

Equation of motion coupled cluster methods for electron attachment and ionization potential in fullerenes C{sub 60} and C{sub 70}

Energy Technology Data Exchange (ETDEWEB)

Bhaskaran-Nair, Kiran [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70802 (United States); Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Kowalski, Karol, E-mail: karol.kowalski@pnnl.gov [William R. Wiley Environmental Molecular Sciences Laboratory, Battelle, Pacific Northwest National Laboratory, K8-91, P.O.Box 999, Richland, Washington 99352 (United States); Moreno, Juana; Jarrell, Mark [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70802 (United States); Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Shelton, William A. [Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)

2014-08-21

In both molecular and periodic solid-state systems there is a need for the accurate determination of the ionization potential and the electron affinity for systems ranging from light harvesting polymers and photocatalytic compounds to semiconductors. The development of a Green's function approach based on the coupled cluster (CC) formalism would be a valuable tool for addressing many properties involving many-body interactions along with their associated correlation functions. As a first step in this direction, we have developed an accurate and parallel efficient approach based on the equation of motion-CC technique. To demonstrate the high degree of accuracy and numerical efficiency of our approach we calculate the ionization potential and electron affinity for C{sub 60} and C{sub 70}. Accurate predictions for these molecules are well beyond traditional molecular scale studies. We compare our results with experiments and both quantum Monte Carlo and GW calculations.

Non-covalent functionalisation of C{sub 30} fullerene by pyrrole-n-carboxylic acid (n=2, 3). Density functional theory studies

Energy Technology Data Exchange (ETDEWEB)

Harismah, Kun [Univ. Muhammadiyah Surakarta (Indonesia). Dept. of Chemical Engineering; Mirzaei, Mahmoud [Isfahan Univ. of Medical Sciences (Iran, Islamic Republic of). Bioinformatics Research Center; Ghasemi, Nahid [Islamic Azad Univ., Arak (Iran, Islamic Republic of). Dept. of Chemistry; Nejati, Mohammad [Islamic Azad Univ., Tehran (Iran, Islamic Republic of). Dept. of Chemistry

2018-04-01

For functionalisation of a representative C{sub 30} fullerene nanostructure by pyrrole-n-carboxylic acid (PnCA; n=2, 3) their stabilities and properties were investigated based on density functional theory calculations. Parallel calculations were also done for C{sub 60} fullerene as evidence for comparing the results. Non-covalent interactions are considered to make the functionalised structures. In contrast with the spherical shape of C{sub 60}, the shape of C{sub 30} fullerene is elliptical; therefore, the functionalisation processes were done for both axial and equatorial elliptical positions (AC{sub 30} and EC{sub 30}). The results indicated that both the positions of C{sub 30} have almost equivalent chances to be functionalised by PnCA; but functionalisation by P2CA is slightly more favourable than P3CA, either for C{sub 60}. The illustrated molecular orbitals' distributions indicated that the direction of charge transfer could be considered from PnCA counterparts to fullerene counterparts. The molecular properties indicated more reactivity for C{sub 30} than for C{sub 60} fullerene. Finally, the atomic scale quadrupole coupling constants indicated different roles for N and O atoms of PnCA in the functionalised models.

Photodissociation of van der Waals clusters of isoprene with oxygen, C{sub 5}H{sub 8}-O{sub 2}, in the wavelength range 213-277 nm

Energy Technology Data Exchange (ETDEWEB)

Vidma, Konstantin V.; Frederix, Pim W. J. M.; Parker, David H. [Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 ED Nijmegen (Netherlands); Baklanov, Alexey V. [Institute of Chemical Kinetics and Combustion, Institutskaja Street 3, Novosibirsk 630090 (Russian Federation) and Novosibirsk State University, Pirogova street 2, Novosibirsk 630090 (Russian Federation)

2012-08-07

The speed and angular distribution of O atoms arising from the photofragmentation of C{sub 5}H{sub 8}-O{sub 2}, the isoprene-oxygen van der Waals complex, in the wavelength region of 213-277 nm has been studied with the use of a two-color dissociation-probe method and the velocity map imaging technique. Dramatic enhancement in the O atoms photo-generation cross section in comparison with the photodissociation of individual O{sub 2} molecules has been observed. Velocity map images of these 'enhanced' O atoms consisted of five channels, different in their kinetic energy, angular distribution, and wavelength dependence. Three channels are deduced to be due to the one-quantum excitation of the C{sub 5}H{sub 8}-O{sub 2} complex into the perturbed Herzberg III state ({sup 3}{Delta}{sub u}) of O{sub 2}. This excitation results in the prompt dissociation of the complex giving rise to products C{sub 5}H{sub 8}+O+O when the energy of exciting quantum is higher than the complex photodissociation threshold, which is found to be 41740 {+-} 200 cm{sup -1} (239.6{+-}1.2 nm). This last threshold corresponds to the photodissociation giving rise to an unexcited isoprene molecule. The second channel, with threshold shifted to the blue by 1480 {+-} 280 cm{sup -1}, corresponds to dissociation with formation of rovibrationally excited isoprene. A third channel was observed at wavelengths up to 243 nm with excitation below the upper photodissociation threshold. This channel is attributed to dissociation with the formation of a bound O atom C{sub 5}H{sub 8}-O{sub 2}+hv{yields} C{sub 5}H{sub 8}-O{sub 2}({sup 3}{Delta}{sub u}) {yields} C{sub 5}H{sub 8}O + O and/or to dissociation of O{sub 2} with borrowing of the lacking energy from incompletely cooled complex internal degrees of freedom C{sub 5}H{sub 8}{sup *}-O{sub 2}+hv{yields} C{sub 5}H{sub 8}{sup *}-O{sub 2}({sup 3}{Delta}{sub u}) {yields} C{sub 5}H{sub 8}+ O + O. The kinetic energy of the O atoms arising in two other

Characteristics of Ti{sub 3}C{sub 2}X–Chitosan Films with Enhanced Mechanical Properties

Energy Technology Data Exchange (ETDEWEB)

Hu, Chunfeng, E-mail: chfhu@live.cn [Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu (China); Shen, Fei [Center of Nanomaterials for Renewable Energy, State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi’an Jiaotong University, Xi’an (China); Zhu, Degui [Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu (China); Zhang, Haibin [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang (China); Xue, Jianming [State Key Laboratory of Nuclear Physics and Technology, Center for Applied Physics and Technology, Peking University, Beijing (China); Han, Xiaogang, E-mail: chfhu@live.cn [Center of Nanomaterials for Renewable Energy, State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi’an Jiaotong University, Xi’an (China)

2017-01-25

Chitosan-reinforced Ti{sub 3}C{sub 2}X films were successfully fabricated by infiltrating Ti{sub 3}C{sub 2}X suspensions containing different chitosan contents followed by vacuum drying. The designed chitosan contents were 0, 7, 10, and 14 wt%. It was determined that as-prepared films had shell-like nanolaminar microstructure. Displacement of Ti{sub 3}C{sub 2}X nanosheets increased from 24.254 Å (0 wt%) to 28.822 Å (10 wt%) and then decreased to 28.132 Å (14 wt%) with increment of chitosan content. Tensile strength of films continuously increased from 8.20 to 43.52 MPa, enhancing 5.3 times. Electrical resistivity of films increased from 0.39 mΩ cm (0 wt%) to 54.91 mΩ cm (14 wt%). Only pure Ti{sub 3}C{sub 2}X film could be used as electrode in the sodium battery.

Stability and isomerization reactions of phenyl cation C{sub 6}H{sub 5}{sup +} isomers

Energy Technology Data Exchange (ETDEWEB)

Shi, Dandan [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun 130012 (China); Yang, Xue [College of Science, Jilin Institute of Chemical Technology, Jilin 132022 (China); Zhang, Xiaomei; Shan, Shimin [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun 130012 (China); Xu, Haifeng, E-mail: xuhf@jlu.edu.cn [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun 130012 (China); Yan, Bing, E-mail: yanbing@jlu.edu.cn [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun 130012 (China)

2016-03-01

Highlights: • A total of 60 isomers of C{sub 6}H{sub 5}{sup +} cations were obtained at density functional theory. • The stability and isomerization reactions of C{sub 6}H{sub 5}{sup +} isomers were performed. • The structures, frequencies, thermodynamic properties of isomers were summarized. • Ring to ring or chain isomerization pathways were investigated using IRC method. • Result shows reactions contain hydrogen transfer, bond broken and reconstruction. - Abstract: As a key polyatomic molecular cation that plays a pivotal role in growth of the polycyclic aromatic hydrocarbons, phenyl cation C{sub 6}H{sub 5}{sup +} exhibits various isomers and isomerization reactions. Investigation on the structure and stability of the isomers as well as the isomerization is important for better understanding the chemical reactions involving C{sub 6}H{sub 5}{sup +} cations. In this work, we have performed a theoretical study on the stability and isomerization reactions of C{sub 6}H{sub 5}{sup +} isomers at density functional theory B3LYP/6-311G (d, p) level. We have obtained a total of 60 isomers of C{sub 6}H{sub 5}{sup +} cations, most of which are reported for the first time. The geometries, vibrational frequencies, thermodynamic properties and stability of 28 out of 60 isomers have been summarized in detail. Different ring-to-ring and ring-to-chain isomerization pathways, which are connected via 28 transition states, have been investigated using the intrinsic reaction coordinate method. The results show that the isomerization reactions occur via hydrogen migration followed by bond-breaking and reconstruction.

Regular approach for generating van der Waals C{sub s} coefficients to arbitrary orders

Energy Technology Data Exchange (ETDEWEB)

Ovsiannikov, Vitali D [Department of Physics, Voronezh State University, 394006 Voronezh (Russian Federation); Mitroy, J [Faculty of Technology, Charles Darwin University, Darwin, NT 0909 (Australia)

2006-01-14

A completely general formalism is developed to describe the energy E{sup disp} = {sigma}{sub s}C{sub s}/R{sup s} of dispersion interaction between two atoms in spherically symmetric states. Explicit expressions are given up to the tenth order of perturbation theory for the dispersion energy E{sup disp} and dispersion coefficients C{sub s}. The method could, in principle, be used to derive the expressions for any s while including all contributing orders of perturbation theory for asymptotic interaction between two atoms. The theory is applied to the calculation of the complete series up to s = 30 for two hydrogen atoms in their ground state. A pseudo-state series expansion of the two-atom Green function gives rapid convergence of the series for radial matrix elements. The numerical values of C{sub s} are computed up to C{sub 30} to a relative accuracy of 10{sup -7} or better. The dispersion coefficients for the hydrogen-antihydrogen interaction are obtained from the H-H coefficients by simply taking the absolute magnitude of C{sub s}.

a.c. conductance study of polycrystal C{sub 60}

Energy Technology Data Exchange (ETDEWEB)

Yan Feng [Nanjing Univ. (China). Nat. Lab. of Solid State Microstructure; Wang Yening [Nanjing Univ. (China). Nat. Lab. of Solid State Microstructure; Huang Yineng [Nanjing Univ. (China). Nat. Lab. of Solid State Microstructure; Gu Min [Nanjing Univ. (China). Nat. Lab. of Solid State Microstructure; Zhang Qingming [Nanjing Univ. (China). Nat. Lab. of Solid State Microstructure; Shen Huimin [Nanjing Univ. (China). Nat. Lab. of Solid State Microstructure

1995-06-05

The a.c. (1C{sub 60} polycrystal (grain size 30 nm) has been studied from 100 to 350 K. Below 150 K, the a.c. conductance is nearly proportional to the temperature and frequency. This is proposed to be due to the hopping of localized states around the Fermi level. Above 200 K, the a.c. conductance exhibits a rapid increase with temperature, and shows a thermally activated behaviour with an activation energy of 0.389 eV below a certain temperature and 0.104 eV above it. A frequency dependent conductance at a fixed temperature is also obtained with a power law {sigma} similar {omega}{sup s} (s{approx}0.8). For a sample of normal grain size, we have measured a peak near 250 K and a much smaller conductance. These results indicate that the defective na ture of our sample (small grain size, disorder or impurities) plays an important role for the transport properties. The existence of nanocrystals in the sample may give rise to localized states and improve its a.c. conductance. The two activation energies can be attributed to the coexistence of the crystalline and amorphous phases of C{sub 60}. ((orig.)).

Utilization of outpatient services in refugee settlement health facilities: a comparison by age, gender, and refugee versus host national status

Directory of Open Access Journals (Sweden)

Meyer Sarah

2011-09-01

Full Text Available Abstract Background Comparisons between refugees receiving health care in settlement-based facilities and persons living in host communities have found that refugees have better health outcomes. However, data that compares utilization of health services between refugees and the host population, and across refugee settlements, countries and regions is limited. The paper will address this information gap. The analysis in this paper uses data from the United Nations High Commissioner of Refugees (UNHCR Health Information System (HIS. Methods Data about settlement populations and the use of outpatient health services were exported from the UNHCR health information system database. Tableau Desktop was used to explore the data. STATA was used for data cleaning and statistical analysis. Differences in various indicators of the use of health services by region, gender, age groups, and status (host national vs. refugee population were analyzed for statistical significance using generalized estimating equation models that adjusted for correlated data within refugee settlements over time. Results Eighty-one refugee settlements were included in this study and an average population of 1.53 million refugees was receiving outpatient health services between 2008 and 2009. The crude utilization rate among refugees is 2.2 visits per person per year across all settlements. The refugee utilization rate in Asia (3.5 was higher than in Africa on average (1.8. Among refugees, females have a statistically significant higher utilization rate than males (2.4 visits per person per year vs. 2.1. The proportion of new outpatient attributable to refugees is higher than that attributable to host nationals. In the Asian settlements, only 2% outpatient visits, on average, were attributable to host community members. By contrast, in Africa, the proportion of new outpatient (OPD visits by host nationals was 21% on average; in many Ugandan settlements, the proportion of outpatient

Utilization of outpatient services in refugee settlement health facilities: a comparison by age, gender, and refugee versus host national status.

Science.gov (United States)

Weiss, William M; Vu, Alexander; Tappis, Hannah; Meyer, Sarah; Haskew, Christopher; Spiegel, Paul

2011-09-21

Comparisons between refugees receiving health care in settlement-based facilities and persons living in host communities have found that refugees have better health outcomes. However, data that compares utilization of health services between refugees and the host population, and across refugee settlements, countries and regions is limited. The paper will address this information gap. The analysis in this paper uses data from the United Nations High Commissioner of Refugees (UNHCR) Health Information System (HIS). Data about settlement populations and the use of outpatient health services were exported from the UNHCR health information system database. Tableau Desktop was used to explore the data. STATA was used for data cleaning and statistical analysis. Differences in various indicators of the use of health services by region, gender, age groups, and status (host national vs. refugee population) were analyzed for statistical significance using generalized estimating equation models that adjusted for correlated data within refugee settlements over time. Eighty-one refugee settlements were included in this study and an average population of 1.53 million refugees was receiving outpatient health services between 2008 and 2009. The crude utilization rate among refugees is 2.2 visits per person per year across all settlements. The refugee utilization rate in Asia (3.5) was higher than in Africa on average (1.8). Among refugees, females have a statistically significant higher utilization rate than males (2.4 visits per person per year vs. 2.1). The proportion of new outpatient attributable to refugees is higher than that attributable to host nationals. In the Asian settlements, only 2% outpatient visits, on average, were attributable to host community members. By contrast, in Africa, the proportion of new outpatient (OPD) visits by host nationals was 21% on average; in many Ugandan settlements, the proportion of outpatient visits attributable to host community members

Utilization of outpatient services in refugee settlement health facilities: a comparison by age, gender, and refugee versus host national status

Science.gov (United States)

2011-01-01

Background Comparisons between refugees receiving health care in settlement-based facilities and persons living in host communities have found that refugees have better health outcomes. However, data that compares utilization of health services between refugees and the host population, and across refugee settlements, countries and regions is limited. The paper will address this information gap. The analysis in this paper uses data from the United Nations High Commissioner of Refugees (UNHCR) Health Information System (HIS). Methods Data about settlement populations and the use of outpatient health services were exported from the UNHCR health information system database. Tableau Desktop was used to explore the data. STATA was used for data cleaning and statistical analysis. Differences in various indicators of the use of health services by region, gender, age groups, and status (host national vs. refugee population) were analyzed for statistical significance using generalized estimating equation models that adjusted for correlated data within refugee settlements over time. Results Eighty-one refugee settlements were included in this study and an average population of 1.53 million refugees was receiving outpatient health services between 2008 and 2009. The crude utilization rate among refugees is 2.2 visits per person per year across all settlements. The refugee utilization rate in Asia (3.5) was higher than in Africa on average (1.8). Among refugees, females have a statistically significant higher utilization rate than males (2.4 visits per person per year vs. 2.1). The proportion of new outpatient attributable to refugees is higher than that attributable to host nationals. In the Asian settlements, only 2% outpatient visits, on average, were attributable to host community members. By contrast, in Africa, the proportion of new outpatient (OPD) visits by host nationals was 21% on average; in many Ugandan settlements, the proportion of outpatient visits attributable

Promoting Ti{sub 4}C{sub 2}S{sub 2} strain induced precipitation during asymmetrical hot rolling to improve r value and advantaged texture in Ti stabilized IF steel

Energy Technology Data Exchange (ETDEWEB)

Dong, Futao, E-mail: dongft@sina.com [College of Metallurgy and Energy, Hebei United University, Tangshan 063000 (China); Xue, Fei [College of Electrical Engineering, Hebei United University, Tangshan 063000 (China); Du, Linxiu; Liu, Xianghua [The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China)

2015-01-25

Highlights: • We study Ti{sub 4}C{sub 2}S{sub 2} strain induced precipitation in Ti stabilized IF steel. • The PTT diagram is obtained by plotting 1/A{sub r}–time curves. • Hot rolling at the nose of P{sub s} line effectively promotes Ti{sub 4}C{sub 2}S{sub 2} precipitation. • Annealed sheet with promoted Ti{sub 4}C{sub 2}S{sub 2} exhibits higher r value and stronger γ fiber texture. • Adverse impact of tiny TiC has been significantly mitigated. - Abstract: The kinetic of Ti{sub 4}C{sub 2}S{sub 2} strain induced precipitation in a Ti stabilized IF steel was investigated using two stage interrupted compression test with high true strain (0.5). The PTT (precipitation–time–temperature) diagram was obtained by plotting 1/A{sub r}–time curves. TEM (transmission electron microscopy) observation confirmed that the evolution of Ti{sub 4}C{sub 2}S{sub 2} precipitate in the quenched samples of thermal simulation is in good agreement with the PTT diagram. Hot strips were produced at three different rolling temperatures with high strain and slight shear deformation. It was found that hot rolling at the nose temperature of the P{sub s} line of the PTT diagram can effectively promote the precipitation of Ti{sub 4}C{sub 2}S{sub 2} and retard the precipitation of TiC. Cold rolled and annealed sheets from hot strip containing higher volume fraction of Ti{sub 4}C{sub 2}S{sub 2} exhibited higher r value and stronger γ fiber texture with equal {1 1 1}〈1 1 2〉 and {1 1 1}〈1 1 0〉 components. By contrast, cold rolled and annealed sheets from hot strips containing lower volume fraction of Ti{sub 4}C{sub 2}S{sub 2} represented lower r values and weaker γ fiber texture with significant drops from {1 1 1}〈1 1 2〉 to {1 1 1}〈1 1 0〉 component.

Evolution of the electronic structure of C{sub 60}/La{sub 0.67}Sr{sub 0.33}MnO{sub 3} interface

Energy Technology Data Exchange (ETDEWEB)

Xie, Haipeng; Niu, Dongmei, E-mail: mayee@csu.edu.cn, E-mail: ygao@pas.rochester.edu; Lyu, Lu; Zhang, Hong; Zhang, Yuhe; Liu, Peng [Institute of Super-Microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Wang, Peng; Wu, Di [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Gao, Yongli, E-mail: mayee@csu.edu.cn, E-mail: ygao@pas.rochester.edu [Institute of Super-Microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States)

2016-01-04

The evolution of the electronic structure at the interface between fullerene (C{sub 60}) and La{sub 0.67}Sr{sub 0.33}MnO{sub 3} (LSMO) has been investigated with ultraviolet photoemission spectroscopy and X-ray photoemission spectroscopy. There is a 0.61 eV barrier for the electrons to be injected from LSMO to C{sub 60}. The energy bands keep bending upward with increasing C{sub 60} thickness. A total energy bending of 0.72 eV is observed, changing the C{sub 60} film from n-type to p-type. The n-p transition is ascribed to the diffusion of oxygen from LSMO to C{sub 60} which subsequently strips electrons from C{sub 60}, making the latter p-type. Our results suggest a buffer layer be inserted between the LSMO and C{sub 60} to lower the interface electron barrier and prevent deterioration of the C{sub 60} film in related spintronic devices.

Ejecting intact large molecular structures by C{sub 60} ion impact upon bio-organic solids; Ejection de tres grandes structures moleculaires intactes par impact de C{sub 60} sur des solides bioorganiques

Energy Technology Data Exchange (ETDEWEB)

Brunelle, A.; Della Negra, S.; Deprun, C.; Depauw, J.; Jacquet, D.; Le Beyec, Y.; Pautrat, N. [Experimental Research Division, Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France); Haakansson, P. [Division of Ion Physics, Angstrom Laboratory, Uppsala Univ. Uppsala (Sweden)

1999-11-01

C{sub 60} molecules accelerated to MeV energies (20 MeV) have been used to induce the desorption-ionization of large bio-molecules from solid samples. In the case of the trypsin molecules, the secondary molecular ion emission yield is about two orders of magnitude larger than with MeV atomic ions. This is a consequence of the very high energy density deposited in solids by 20 MeV C{sub 60} projectiles that gives rise to a large amount of matter ejected after each impact. Although time-of-flight mass spectra can be recorded within a few seconds, it is more the mechanistic aspects in comparison with other particle induced desorption methods, which are the objective of these first results with energetic fullerenes. (authors) 1 fig.

Measurement of the C{sub 2}H{sub 2} destruction kinetics by infrared laser absorption spectroscopy in a pulsed low pressure dc discharge

Energy Technology Data Exchange (ETDEWEB)

Rousseau, A [LPTP, Ecole Polytechnique, CNRS, Route de Saclay, 91 128 Palaiseau Cedex (France); Guaitella, O [LPTP, Ecole Polytechnique, CNRS, Route de Saclay, 91 128 Palaiseau Cedex (France); Gatilova, L [LPTP, Ecole Polytechnique, CNRS, Route de Saclay, 91 128 Palaiseau Cedex (France); Hannemann, M [INP-Greifswald, Friedrich-Ludwig-Jahn-Str. 19, 17489 Greifswald (Germany); Roepcke, J [INP-Greifswald, Friedrich-Ludwig-Jahn-Str. 19, 17489 Greifswald (Germany)

2007-04-07

The kinetics of destruction of C{sub 2}H{sub 2} is investigated in a low pressure pulsed dc discharge in dry air. Tuneable diode laser absorption spectroscopy in the mid-infrared region (1350 cm{sup -1}) has been used to measure the influence of (i) the pulse duration (ii) the pulse repetition rate and (iii) the pulse current on the C{sub 2}H{sub 2} concentration in situ the discharge tube. First, it is shown that in the plasma region under flow conditions the time averaged concentration of C{sub 2}H{sub 2} depends only on the time averaged discharge current. Second, time resolved measurements have been performed in a closed reactor, i.e. under static conditions. A simple kinetic modelling of the pulsed discharge leads to a good agreement with the experimental results and shows that the oxidation rate of C{sub 2}H{sub 2} is mainly controlled by the time averaged concentration of O atoms. Finally, the influence of porous TiO{sub 2} photocatalyst on the C{sub 2}H{sub 2} oxidation rate is reported.

Biosynthesis of 24-methylsterols from (1,2-/sup 13/C/sub 2/) acetate; dihydrobrassicasterol and campesterol in tissue cultures of Physalis peruviana and ergosterol in yeast

Energy Technology Data Exchange (ETDEWEB)

Seo, S.; Uomori, A.; Yoshimura, Y.; Takeda, K. (Shionogi and Co. Ltd., Osaka (Japan). Research Lab.)

1984-09-01

The /sup 13/C labelling patterns of the two methyl groups at C-25 of dihydrobrassicasterol biosynthesized from (1,2-/sup 13/C/sub 2/) acetate differ from those of campesterol and 24-methylenecholesterol obtained from cultured cells of Physalis peruviana and ergosterol from yeast.

Interaction of multicharged ions with molecules (CO{sub 2}, C{sub 60}) by coincident electron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Moretto-Capelle, P.; Bordenave-Montesquieu, D.; Bordenave-Montesquieu, A. [Universite Paul Sabatier, Toulouse (France). Lab. CAR-IRSAMC

2001-07-01

First results for the investigation of electron capture processes in collisions between multicharged ions and molecule targets using electron spectroscopy in coincidence with charged fragments, are presented. It is shown that a much more detailed investigation of the capture reaction can be achieved using molecular instead of heavy atomic targets provided that an analysis of the target dissociation is made. The collisional systems {sup 18}O{sup 8+}+Ar, CO{sub 2} and C{sub 60} have been studied at 80 keV. Non coincident electron spectra as well as first results of double or triple coincidence experiments are discussed. Kinetic energy distributions of the C{sub n}{sup +} fragments (n=1 to 8) produced in multiple capture processes from C{sub 60} target are given. A detailed investigation of the double capture process with CO{sub 2} molecule allows the measurement of kinetic energy release distributions (KERD) which characterize the dissociation of CO{sub 2}{sup 2+} molecular ions; our results are found to be very similar to those measured in double photoionisation experiments. (orig.)

Optical and magneto-optical properties of the monoclinic phase of the C{sub 70} crystal

Energy Technology Data Exchange (ETDEWEB)

Yaghobi, Mojtaba [Islamic Azad University, Ayatollah Amoli Branch, Amol (Iran, Islamic Republic of); Koohi, Ardavan, E-mail: m.yaghoubi@iauamol.ac.i [Plasma Physics and Nuclear Fusion Research School, Nuclear Science and Technology Research Institute, AEOI, Tehran (Iran, Islamic Republic of)

2010-12-15

Using the Hartree-Fock (HF) single-excitation configuration interaction (CI) model in conjunction with the local field method, the dielectric tensor, birefringence coefficient, circular dichroism, refractive index and effects of spatial dispersion on the dispersion relation for transverse normal polariton waves of the monoclinic phase of the C{sub 70} crystal are calculated. Our results indicate that the anisotropy of the C{sub 70} molecule remains in C{sub 70} solids. Also, our results on the effect of spatial dispersion, compared with the non-dispersive case, indicate that the coupling of the transverse electromagnetic field with the first and second excitonic states is very weak.

Bubble-point pressures of some selected methane + synthetic C{sub 6+} mixtures

Energy Technology Data Exchange (ETDEWEB)

Shariati, A.; Moshfeghian, M. [Shiraz Univ. (Iran, Islamic Republic of). Dept. of Chemical Engineering; Peters, C.J. [Delft Univ. of Technology (Netherlands). Lab. of Applied Thermodynamics and Phase Equilibria

1998-03-01

In this work, a series of bubble-point measurements were carried out on some synthetic C{sub 6+} mixtures in the presence of methane. These synthetic mixtures included alkanes, cycloalkanes, and aromatics. The experiments were carried out using the Cailletet apparatus, and bubble-point pressures were measured in a temperature range of 311--470 K. The corresponding pressures were predicted using the Peng-Robinson equation of state, and the relative errors were estimated. It is shown that such synthetic C{sub 6+} mixtures can be simulated reasonably well by this equation of state.

Human serum albumin interactions with C{sub 60} fullerene studied by spectroscopy, small-angle neutron scattering, and molecular dynamics simulations

Energy Technology Data Exchange (ETDEWEB)

Li, Song [Vanderbilt University, Department of Chemical and Biomolecular Engineering (United States); Zhao, Xiongce [NIDDK, National Institutes of Health (United States); Mo, Yiming [Institute of Agriculture, University of Tennessee (United States); Cummings, Peter T., E-mail: cummingspt@ornl.gov [Vanderbilt University, Department of Chemical and Biomolecular Engineering (United States); Heller, William T., E-mail: hellerwt@ornl.gov [Oak Ridge National Laboratory, Center for Structural Molecular Biology (United States)

2013-07-15

Concern about the toxicity of engineered nanoparticles, such as the prototypical nanomaterial C{sub 60} fullerene, continues to grow. While, evidence continues to mount that C{sub 60} and its derivatives may pose health hazards, the specific molecular interactions of these particles with biological macromolecules require further investigation. In this article, we report combined experimental and theoretical studies on the interaction of one of the most prevalent proteins in the human body, human serum albumin (HSA), with C{sub 60} in an aqueous environment. The C{sub 60}-HSA interaction was probed by circular dichroism (CD) spectroscopy, small-angle neutron scattering (SANS), and atomistic molecular dynamics (MD) simulations to understand C{sub 60}-driven changes in the structure of HSA in solution. The CD spectroscopy demonstrates that the secondary structure of the protein decreases in {alpha}-helical content in response to the presence of C{sub 60} (0.68 nm in diameter). Similarly, C{sub 60} produces subtle changes in the solution conformation of HSA (an 8.0 nm Multiplication-Sign 3.8 nm protein), as evidenced by the SANS data and MD simulations, but the data do not indicate that C{sub 60} changes the oligomerization state of the protein, such as by inducing aggregation. The results demonstrate that the interaction is not highly disruptive to the protein in a manner that would prevent it from performing its physiological function.

Pseudo Jahn–Teller effect in distortion and restoration of planar configurations of tetra-heterocyclic 1,2-diazetes C{sub 2}N{sub 2}E{sub 4}, E = H, F, Cl, Br

Energy Technology Data Exchange (ETDEWEB)

Ilkhani, Ali R. [Institute for Theoretical Chemistry, University of Texas at Austin, Austin, TX 78712 (United States); Department of Chemistry, Yazd Branch, Islamic Azad University, Yazd (Iran, Islamic Republic of); Gorinchoy, Natalia N. [Institute of Chemistry, Academy of Sciences of Moldova, Chisinau, Republic of Moldova (Moldova, Republic of); Bersuker, Isaac B., E-mail: bersuker@cm.utexas.edu [Institute for Theoretical Chemistry, University of Texas at Austin, Austin, TX 78712 (United States); Institute of Chemistry, Academy of Sciences of Moldova, Chisinau, Republic of Moldova (Moldova, Republic of)

2015-10-16

Highlights: • The pseudo Jahn–Teller mechanism of puckering of tetracyclic 1,2-diazetes is revealed. • Vibronic constants are extracted from ab initio calculations versus PJTE equations. • Methods of restoring the planar configuration by external perturbations are suggested. - Abstract: The pseudo Jahn–Teller effect (PJTE) is employed to explain the origin of the puckered structures of tetra-heterocyclic 1,2-diazetes, C{sub 2}N{sub 2}E{sub 4}, E = H, F, Cl, Br, and to reveal the conditions of restoration of their planar configuration. The high-symmetry C{sub 2v} planar configuration of all these compounds is unstable with respect to puckering, a{sub 2}-type distortions produced by the PJT coupling between their ground {sup 1}A{sub 1} and excited {sup 1}A{sub 2} electronic states. The PJTE coupling constants are estimated by fitting ab initio calculated energy profiles to the formulas of the vibronic coupling problem (A{sub 1} + A{sub 2}) ⊗ a{sub 2}. The conditions for the restoration of the planar configurations of the C{sub 2}N{sub 2}E{sub 4} cycles were revealed: the PJTE can be quenched by removing the outer two electrons, e.g. by producing a “triple-decker sandwich” structure with two electron acceptors on both sides of the neutral cycle.

Enhancement of ambipolar characteristics in single-walled carbon nanotubes using C{sub 60} and fabrication of logic gates

Energy Technology Data Exchange (ETDEWEB)

Park, Steve [Department of Materials Science and Engineering, Stanford University, Durand Building, 496 Lomita Mall, Stanford, California 94305-4034 (United States); Nam, Ji Hyun [Department of Electrical Engineering, Stanford University, David Packard Building, 350 Serra Mall, Mail Code: 9505, Stanford, California 94305-9505 (United States); Koo, Ja Hoon; Lei, Ting; Bao, Zhenan, E-mail: zbao@stanford.edu [Department of Chemical Engineering, Stanford University, Shriram Center, 443 Via Ortega, Room 307, Stanford, California 94305-4145 (United States)

2015-03-09

We demonstrate a technique to convert p-type single-walled carbon nanotube (SWNT) network transistor into ambipolar transistor by thermally evaporating C{sub 60} on top. The addition of C{sub 60} was observed to have two effects in enhancing ambipolar characteristics. First, C{sub 60} served as an encapsulating layer that enhanced the ambipolar characteristics of SWNTs. Second, C{sub 60} itself served as an electron transporting layer that contributed to the n-type conduction. Such a dual effect enables effective conversion of p-type into ambipolar characteristics. We have fabricated inverters using our SWNT/C{sub 60} ambipolar transistors with gain as high as 24, along with adaptive NAND and NOR logic gates.

Ionization, evaporation and fragmentation of C{sub 60} in collisions with highly charged C, O and F ions-effect of projectile charge state

Energy Technology Data Exchange (ETDEWEB)

Kelkar, A H; Misra, D; Tribedi, L C [Tata Institute of Fundamental Research, Colaba, Mumbai -5 (India)

2007-09-15

We study the various inelastic processes such ionization, fragmentation and evaporation of C{sub 60} molecule in collisions with fast heavy ions. We have used 2.33 MeV/u C, O and F projectile ion beams. Various ionization and fragmentation products were detected using time-of-flight mass spectrometer. The multiply charged C{sub 60}{sup r+} ions were detected for maximum r = 4. The projectile charge state (q{sub p}) dependence of the single and double ionization cross sections is well reproduced by a model based on the giant dipole plasmon resonance (GDPR). The q{sub p}-dependence of the fragmentation yields, was found to be linear. Variation of relative yields of the evaporation products of C{sub 60}{sup 2+} (i.e. C{sub 58}{sup 2+}, C{sub 56}{sup 2+} etc) and C{sub 60}{sup 3+} (i.e. C{sub 58}{sup 3+}, C{sub 56}{sup 3+} etc) with q{sub p} has also been investigated for various projectiles.

Production of anti-fullerene C{sub 60} polyclonal antibodies and study of their interaction with a conjugated form of fullerene

Energy Technology Data Exchange (ETDEWEB)

Hendrickson, O. D., E-mail: odhendrick@gmail.com; Fedyunina, N. S. [Russian Academy of Sciences, Institute of Biochemistry (Russian Federation); Martianov, A. A. [Moscow State University (Russian Federation); Zherdev, A. V.; Dzantiev, B. B. [Russian Academy of Sciences, Institute of Biochemistry (Russian Federation)

2011-09-15

The aim of this study was to produce anti-fullerene C{sub 60} antibodies for the development of detection systems for fullerene C{sub 60} derivatives. To produce anti-fullerene C{sub 60} antibodies, conjugates of the fullerene C{sub 60} carboxylic derivative with thyroglobulin, soybean trypsin inhibitor, and bovine serum albumin were synthesized by carbodiimide activation and characterized. Immunization of rabbits by the conjugates led to the production of polyclonal anti-fullerene antibodies. The specificity of the immune response to fullerene was investigated. Indirect competitive immunoenzyme assay was developed for the determination of conjugated fullerene with detection limits of 0.04 ng/mL (calculated for coupled C{sub 60}) and 0.4 ng/mL (accordingly to total fullerene-protein concentration).

Solvent-free functionalization of fullerene C{sub 60} and pristine multi-walled carbon nanotubes with aromatic amines

Energy Technology Data Exchange (ETDEWEB)

Ramírez-Calera, Itzel J. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510, México, D.F. (Mexico); Meza-Laguna, Victor [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510 México, D.F. (Mexico); Gromovoy, Taras Yu. [O.O. Chuiko Institute of Surface Chemistry, National Academy of Sciences of the Ukraine, Gen. Naumova 17, 03164 Kiev (Ukraine); Chávez-Uribe, Ma. Isabel [Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510 México, D.F. (Mexico); Basiuk, Vladimir A., E-mail: basiuk@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510 México, D.F. (Mexico); Basiuk, Elena V., E-mail: elbg1111@gmail.com [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior C. U., 04510, México, D.F. (Mexico)

2015-02-15

Highlights: • Pristine multi-walled carbon nanotubes were functionalized with aromatic amines. • The amines add onto nanotube defects, likewise they add onto fullerene C{sub 60}. • The addition takes place at elevated temperature and without organic solvents. • Functionalized nanotubes were characterized by a number of instrumental techniques. - Abstract: We employed a direct one-step solvent-free covalent functionalization of solid fullerene C{sub 60} and pristine multi-walled carbon nanotubes (MWCNTs) with aromatic amines 1-aminopyrene (AP), 2-aminofluorene (AF) and 1,5-diaminonaphthalene (DAN). The reactions were carried out under moderate vacuum, in a wide temperature range of 180–250 °C, during relatively short time of about 2 h. To confirm successful amine attachment, a large number of analytical techniques were used (depending on the nanomaterial functionalized) such as Fourier transform infrared, Raman, X-ray photoelectron, {sup 13}C cross-polarization magic angle spinning NMR spectroscopy, thermogravimetric analysis, laser-desorption ionization time-of-flight mass spectrometry, temperature-programmed desorption with mass spectrometric detection, as well as scanning and transmission electron microscopy. The nucleophilic addition of the aromatic amines to C{sub 60} molecule was studied theoretically by using density functional theory (PBE GGA functional with Grimme dispersion correction in conjunction with the DNP basis set). In the case of crystalline C{sub 60}, the solvent-free technique has a limited applicability due to poor diffusion of vaporous aromatic amines into the bulk. Nevertheless, the approach proposed allows for a facile preparation of aromatic amine-functionalized pristine MWCNTs without contamination with other chemical reagents, detergents and solvents, which is especially important for a vast variety of nanotube applications spanning from nanoelectronics to nanomedicine.

Softening of the elastic shear mode C{sub 66} in iron-based superconductors

Energy Technology Data Exchange (ETDEWEB)

Boehmer, Anna; Burger, Philipp [Karlsruher Institut fuer Technologie, Institut fuer Festkoerperphysik, D-76021 Karlsruhe (Germany); Karlsruher Institut fuer Technologie, Fakultaet fuer Physik, D-76128 Karlsruhe (Germany); Hardy, Frederic; Schweiss, Peter; Fromknecht, Rainer; Wolf, Thomas; Meingast, Christoph [Karlsruher Institut fuer Technologie, Institut fuer Festkoerperphysik, D-76021 Karlsruhe (Germany); Reinecker, Marius; Schranz, Wilfried [Universitaet Wien, Fakultaet fuer Physik, A-1090 Wien, Vienna (Austria)

2013-07-01

The structural phase transition of underdoped iron-based superconductors is accompanied by a large softening of the elastic shear mode C{sub 66}, which has attracted considerable attention. This softening has been discussed both in terms of orbital and spin-nematic fluctuations which would be responsible for the structural phase transition and, possibly, superconductivity. However, sample requirements have so far restricted experimental investigations of C{sub 66} (via measurements of the ultrasound velocity) to the Ba(Fe,Co){sub 2}As{sub 2} system. Here, we report on a new technique, based on a three-point bending setup, to probe the Young's modulus of a sample with a capacitance dilatometer. For certain orientations, the Young's modulus is related to the elastic constant C{sub 66} whose effective temperature dependence can be obtained. Platelet-like samples, as frequently encountered for iron-based systems, are easily studied with our setup. Data on several systems are presented and discussed.

MsmK, an ATPase, Contributes to Utilization of Multiple Carbohydrates and Host Colonization of Streptococcus suis.

Science.gov (United States)

Tan, Mei-Fang; Gao, Ting; Liu, Wan-Quan; Zhang, Chun-Yan; Yang, Xi; Zhu, Jia-Wen; Teng, Mu-Ye; Li, Lu; Zhou, Rui

2015-01-01

Acquisition and metabolism of carbohydrates are essential for host colonization and pathogenesis of bacterial pathogens. Different bacteria can uptake different lines of carbohydrates via ABC transporters, in which ATPase subunits energize the transport though ATP hydrolysis. Some ABC transporters possess their own ATPases, while some share a common ATPase. Here we identified MsmK, an ATPase from Streptococcus suis, an emerging zoonotic bacterium causing dead infections in pigs and humans. Genetic and biochemistry studies revealed that the MsmK was responsible for the utilization of raffinose, melibiose, maltotetraose, glycogen and maltotriose. In infected mice, the msmK-deletion mutant showed significant defects of survival and colonization when compared with its parental and complementary strains. Taken together, MsmK is an ATPase that contributes to multiple carbohydrates utilization and host colonization of S. suis. This study gives new insight into our understanding of the carbohydrates utilization and its relationship to the pathogenesis of this zoonotic pathogen.

Transport biofuel yields from food and lignocellulosic C{sub 4} crops

Energy Technology Data Exchange (ETDEWEB)

Reijnders, L. [IBED University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam (Netherlands)

2010-01-15

In the near future, the lignocellulosic C{sub 4} crops Miscanthus and switchgrass (Panicum virgatum) are unlikely to outcompete sugarcane (Saccharum officinarum) in net energetic yearly yield of transport biofuel ha{sup -1}. This holds both for the thermochemical conversion into liquid hydrocarbons and the enzymatic conversion into ethanol. Currently, Miscanthus and switchgrass would also not seem able to outcompete corn (Zea mays) in net energetic yearly yield of liquid transport biofuel ha{sup -1}, but further development of these lignocellulosic crops may gradually lead to a different outcome. (author)

Electronic excitation induced modification in fullerene C{sub 70} thin films

Energy Technology Data Exchange (ETDEWEB)

Sharma, Pooja [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Singhal, R., E-mail: rsinghal.phy@mnit.ac.in [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Banerjee, M.K. [Department of Metallurgical & Materials Engineering, Malaviya National Institute of Technology, Jaipur 302017 (India); Vishnoi, R. [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Department of Physics, Vardhman - PG College, Bijnor 246701, UP (India); Kaushik, R. [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Department of Physics, Shri K.K. Jain - PG College, Khatauli, UP (India); Singh, F. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

2016-07-15

Fullerene C{sub 70} thin films were deposited by resistive heating on glass substrates and the thickness were approximated to be 150 nm. The effect of energy deposition by 55 MeV Si ions on the optical and structural properties of the prepared thin film samples is investigated. The samples were irradiated with 55 MeV Si ions within fluence range from 1 × 10{sup 12} to 3 × 10{sup 13} ions/cm{sup 2}. For optical studies, the pristine and the Si ion irradiated samples are examined by UV–visible absorption spectroscopy and Raman spectroscopy. UV–visible absorption studies reveal that the absorption peaks of irradiated samples decrease with a decrease in the band gap of the thin films. The damage cross-section (σ) and radius of damaged cylindrical zone (r) are determined as ∼0.6 × 10{sup −13} cm{sup 2} and ∼1.41 nm, respectively from the Raman spectra. Raman studies also suggest that at higher fluence (up to 3 × 10{sup 13} ions/cm{sup 2}), the damage caused by the SHI results in partial amorphization of fullerene C{sub 70} thin film. Modification in the surface properties has been investigated by atomic force microscopy; it has revealed that the roughness decreases and average particle size increases with the increase in fluences.

Surfactant-free fabrication of fullerene C{sub 60} nanotubules under shear

Energy Technology Data Exchange (ETDEWEB)

Vimalanathan, Kasturi; Raston, Colin L. [Flinders Centre for NanoScale Science Technology (CNST) Chemical and Physical Sciences, Flinders University, Adelaide (Australia); Shrestha, Rekha Goswami [International Centre for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki (Japan); Zhang, Zhi; Zou, Jin [Materials Engineering and Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, QLD (Australia); Nakayama, Tomonobu [International Centre for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki (Japan); Graduate School of Pure and Applied Sciences, University of Tsukuba, Ibaraki (Japan)

2017-07-10

A method for controlling the self-assembly of fullerene C{sub 60} molecules into nanotubules in the fcc phase, devoid of entrapped solvent, has been established in a thin film microfluidic device. The micron length C{sub 60} nanotubules, with individual hollow diameters of 100 to 400 nm, are formed under continuous flow processing during high shear micromixing of water and a toluene solution of the fullerene, in the absence of surfactant, and without the need for further down-stream processing. TEM revealed pores on the surface of the nanotubes, and the isolated material has a much higher response to small molecule sensing than that for analogous material formed using multistep batch processing. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Microstructure and microhardness characterization of Cr{sub 3}C{sub 2}-SiC coatings produced by the plasma transferred arc method

Energy Technology Data Exchange (ETDEWEB)

Islak, Serkan [Kastamonu Univ. (Turkey). Cide Rifat Ilgaz Vocational High School; Eski, Oezkan [Kastamonu Univ. (Turkey). Kastamonu Vocational High School; Buytoz, Soner [Firat Univ., Elazig (Turkey). Dept. of Metallurgy and Materials Engineering; Karagoez, Muzaffer [Bartin Univ. (Turkey). Dept. of Metallurgical and Materials Engineering; Stokes, Joseph [Dublin City Univ. (Ireland). School of Mechanical and Manufacturing Engineering

2012-07-01

The purpose of this work was to investigate the coatings made of Cr{sub 3}C{sub 2} and SiC powder manufactured on AISI 304 stainless steel applied by the plasma transferred arc (PTA) welding process. SiC content in the produced coated layer was varied between 0-100 wt. % and the effect of SiC concentration on the microstructure and hardness of the coating was measured experimentally. SEM analyses revealed that the composite coatings had a homogeneous, nonporous, and crack-free microstructure. Dendrites and interdendrite eutectics formed on the coating layer, subject to the temperature gradient and the solidification ratio. There was a significant increase in the hardness of coating layers with the effect of the {gamma}-(Fe,Ni), Cr{sub 7}C{sub 3}, Cr{sub 23}C{sub 6}, Fe{sub 5}C{sub 2}, Cr{sub 3}Si, CrSi{sub 2}, Fe{sub 0.64}Ni{sub 0.36}, CFe{sub 15.1}, C-(Fe,Cr)-Si phases formed in the microstructure. In comparison to the substrate, the microhardness of the coatings produced by PTA were 2.5-3.5 times harder. (orig.)

Host reproductive phenology drives seasonal patterns of host use in mosquitoes.

Directory of Open Access Journals (Sweden)

Nathan D Burkett-Cadena

2011-03-01

Full Text Available Seasonal shifts in host use by mosquitoes from birds to mammals drive the timing and intensity of annual epidemics of mosquito-borne viruses, such as West Nile virus, in North America. The biological mechanism underlying these shifts has been a matter of debate, with hypotheses falling into two camps: (1 the shift is driven by changes in host abundance, or (2 the shift is driven by seasonal changes in the foraging behavior of mosquitoes. Here we explored the idea that seasonal changes in host use by mosquitoes are driven by temporal patterns of host reproduction. We investigated the relationship between seasonal patterns of host use by mosquitoes and host reproductive phenology by examining a seven-year dataset of blood meal identifications from a site in Tuskegee National Forest, Alabama USA and data on reproduction from the most commonly utilized endothermic (white-tailed deer, great blue heron, yellow-crowned night heron and ectothermic (frogs hosts. Our analysis revealed that feeding on each host peaked during periods of reproductive activity. Specifically, mosquitoes utilized herons in the spring and early summer, during periods of peak nest occupancy, whereas deer were fed upon most during the late summer and fall, the period corresponding to the peak in births for deer. For frogs, however, feeding on early- and late-season breeders paralleled peaks in male vocalization. We demonstrate for the first time that seasonal patterns of host use by mosquitoes track the reproductive phenology of the hosts. Peaks in relative mosquito feeding on each host during reproductive phases are likely the result of increased tolerance and decreased vigilance to attacking mosquitoes by nestlings and brooding adults (avian hosts, quiescent young (avian and mammalian hosts, and mate-seeking males (frogs.

Perturbed angular correlation study of the static and dynamic aspects of cadmium and mercury atoms inside and attached to a C{sub 60} fullerene cage

Energy Technology Data Exchange (ETDEWEB)

Das, Satyendra K.; Guin, Rashmohan; Banerjee, Debasish [Variable Energy Cyclotron Centre, Kolkata (India). Accelerator Chemistry Section (Bhabha Atomic Research Centre); Johnston, Karl [CERN, Geneva (Switzerland); Das, Parnika [Variable Energy Cyclotron Centre, Kolkata (India); Butz, Tilman [Leipzig Univ. (Germany). Faculty of Physics and Earth Sciences; Amaral, Vitor S. [Aveiro Univ. (Portugal). Physics Dept.; Aveiro Univ. (Portugal). CICECO; Correia, Joao G.; Barbosa, Marcelo B. [Instituto Tecnologico e Nuclear (ITN), Sacavem (Portugal); CERN, Geneva (Switzerland). ISOLDE

2014-10-15

30 keV {sup 111m}Cd and 50 keV {sup 199m}Hg beams from ISOLDE were used to implant on preformed targets of C{sub 60} with a thickness of 1 mg cm{sup -2}. Endofullerene compounds, viz. {sup 111m}Cd rate at C{sub 60} and {sup 199m}Hg rate at C{sub 60} formed during implantation were separated by filtration through micropore filter paper followed by solvent extraction. Dried samples of the endofullerene compounds were counted for the time differential perturbed angular correlation (TDPAC) measurement using the coincidence of the 151-245keV cascade of {sup 111m}Cd and the 374-158 keV cascade of {sup 199m}Hg on a six LaBr{sub 3}(Ce) detector system coupled with digital electronics. The results for {sup 111m}Cd rate at C{sub 60} indicate a single static component (27 %) and a fast relaxing component (73 %), the latter implying that the cadmium atom moves rapidly inside the cage at room temperature. The quadrupole interaction frequency and asymmetry parameter of the cadmium atom occupying the static site in C{sub 60} are ω{sub Q} = 8.21(36) Mrad s{sup -1} and η = 0.41(9), respectively. The fast relaxation constant is 0.0031(4) ns{sup -1}. Similarly, mercury atoms also exhibit a single static and a fast component. The static site has a quadrupole frequency ω{sub Q} = 283.0(12.4) Mrad s{sup -1} and η = 0 with a fraction of 30 %. The fast relaxation constant is 0.045(8) ns{sup -1} with a fraction of 70 %, very similar to that of cadmium.

HOST PLANT UTILIZATION, HOST RANGE OSCILLATIONS AND DIVERSIFICATION IN NYMPHALID BUTTERFLIES: A PHYLOGENETIC INVESTIGATION

Science.gov (United States)

Nylin, Sören; Slove, Jessica; Janz, Niklas

2014-01-01

It has been suggested that phenotypic plasticity is a major factor in the diversification of life, and that variation in host range in phytophagous insects is a good model for investigating this claim. We explore the use of angiosperm plants as hosts for nymphalid butterflies, and in particular the evidence for past oscillations in host range and how they are linked to host shifts and to diversification. At the level of orders of plants, a relatively simple pattern of host use and host shifts emerges, despite the 100 million years of history of the family Nymphalidae. We review the evidence that these host shifts and the accompanying diversifications were associated with transient polyphagous stages, as suggested by the “oscillation hypothesis.” In addition, we investigate all currently polyphagous nymphalid species and demonstrate that the state of polyphagy is rare, has a weak phylogenetic signal, and a very apical distribution in the phylogeny; we argue that these are signs of its transient nature. We contrast our results with data from the bark beetles Dendroctonus, in which a more specialized host use is instead the apical state. We conclude that plasticity in host use is likely to have contributed to diversification in nymphalid butterflies. PMID:24372598

Catalysis by mixed oxide perovskites. II. The hydrogenolysis of C/sub 3/-C/sub 5/ hydrocarbons on LaCoO/sub 3/

Energy Technology Data Exchange (ETDEWEB)

Ichimura, K; Inoue, Y; Yasumori, I

1981-06-01

The catalytic hydrogenolysis of C/sub 3/ to C/sub 5/ alkanes on LaCoO/sub 3/ perovskite oxide was found to show a highly selective formation of methane in the temperature range of 350 to 620 K. The reaction order with respect to the hydrocarbon pressure was unity in every hydrogenolysis, whereas, the hydrogen order increased from zero for propane to 1.0 for butane and isobutane and to 2.0 for pentane, isopentane, and neopentane. The activation energies of the reactions ranged from 120 for propane to 32 kJ mol/sup -1/ for butane. The reaction of propane or butane with D/sub 2/ on LaCoO/sub 3/ provided large fractions of methane (D/sub 3/) and (D/sub 4/), but a negligible amount of deuterium-exchanged alkanes. An equilibrium among the gaseous H/sub 2/, HD and D/sub 2/ was reached. These hydrogenolyses are described by a mechanism involving the almost concurrent rupture of all the carbon-carbon bonds in the alkanes by the attack of adsorbed hydrogen atoms, and were proposed to be catalyzed by a synergetic effect; the CO/sup 3 +/ ion is effective in breaking the C-C bond, whereas the La/sup 3 +/ and O/sup 2 -/ ions serve to supply hydrogen atoms to the decomposed species. The reaction of propene or butenes with hydrogen produced the corresponding alkanes and methane. The kinetic analyses showed that the fractions of methane produced consecutively via the alkanes amounted to 16% for propene and to more than 93% for butenes. The observed pressure dependence and deuterium distributions in the alkene hydrogenation were interpreted in terms of the associative mechanism. The correlation between the structures of the reactant molecules and of the active sites present on LaCoO/sub 3/ was briefly discussed.

Wolbachia utilizes host microtubules and Dynein for anterior localization in the Drosophila oocyte.

Directory of Open Access Journals (Sweden)

Patrick M Ferree

2005-10-01

Full Text Available To investigate the role of the host cytoskeleton in the maternal transmission of the endoparasitic bacteria Wolbachia, we have characterized their distribution in the female germ line of Drosophila melanogaster. In the germarium, Wolbachia are distributed to all germ cells of the cyst, establishing an early infection in the cell destined to become the oocyte. During mid-oogenesis, Wolbachia exhibit a distinct concentration between the anterior cortex and the nucleus in the oocyte, where many bacteria appear to contact the nuclear envelope. Following programmed rearrangement of the microtubule network, Wolbachia dissociate from this anterior position and become dispersed throughout the oocyte. This localization pattern is distinct from mitochondria and all known axis determinants. Manipulation of microtubules and cytoplasmic Dynein and Dynactin, but not Kinesin-1, disrupts anterior bacterial localization in the oocyte. In live egg chambers, Wolbachia exhibit movement in nurse cells but not in the oocyte, suggesting that the bacteria are anchored by host factors. In addition, we identify mid-oogenesis as a period in the life cycle of Wolbachia in which bacterial replication occurs. Total bacterial counts show that Wolbachia increase at a significantly higher rate in the oocyte than in the average nurse cell, and that normal Wolbachia levels in the oocyte depend on microtubules. These findings demonstrate that Wolbachia utilize the host microtubule network and associated proteins for their subcellular localization in the Drosophila oocyte. These interactions may also play a role in bacterial motility and replication, ultimately leading to the bacteria's efficient maternal transmission.

Pseudo Jahn–Teller distortion for a tricyclic carbon sulfide (C{sub 6}S{sub 8}) and its suppression in S-oxygenated dithiine (C{sub 4}H{sub 4}(SO{sub 2}){sub 2})

Energy Technology Data Exchange (ETDEWEB)

Pratik, Saied Md.; Chowdhury, Chandra; Bhattacharjee, Rameswar; Jahiruddin, Sk.; Datta, Ayan, E-mail: spad@iacs.res.in

2015-10-16

Highlights: • DFT calculations show that sulfur rich cyclic molecules are generally distorted. • Such distortions are shown to arise from Pseudo Jahn–Teller (PJT) effects. • Low OMO–UMO gaps leads to strong vibronic instability for these systems. • Increasing the OMO–UMO gaps by substituting electronegative groups on the cyclic rings decreases PJT effects. • Suppressed PJT instability lead to planar sulfur rich cyclic molecules. - Abstract: The tricyclic carbon-sulfide, C{sub 6}S{sub 8} molecule containing two S-atoms in the 1,4-position of the central six-membered ring and one disulfide (S−S) and one thione (C=S) bond on the five membered rings on its either side (1) possesses a “butterfly flapping” type distorted ground state in the gas-phase and also in β-phase of the crystal. For the isolated molecule, better consideration of the S…S non-bonding interactions in the dithiine ring in the bent form at the M06-2X/6-31+G(d,p) level leads to a significant barrier for inversion of 2.4 kcal/mol which is 2–3 times more than that previously obtained by Weber and Dolg at the B3LYP/cc-pVTZ level due to underestimation of dispersion interactions at the B3LYP level. The origin of the distortion leading to lowering of symmetry for 1 (C{sub 2h} → C{sub 2}) is traced to vibronic mixing between the ground state (Ag) and the low lying excited states of A{sub u} symmetry through the a{sub u} normal mode, a (1A{sub g} + 1A{sub u} + 2A{sub u} + 3A{sub u}) × a{sub u} pseudo Jahn–Teller effect (PJTE) problem. Based on fitting of the ground state APES to the lowest root of the 4 × 4 secular determinant, we calculate the linear vibronic coupling constants (F{sub 0i}) between the relevant states. Similar in class to 1, the S-oxygenated derivative of dithiine, C{sub 4}H{sub 4}(SO{sub 2}){sub 2} (2) unlike most other dithiines, remains planar. The absence of the butterfly-type puckered structure in 2 is traced to the enhanced gap (Δ{sub 0}) and very small

Free radical hydrogen atom abstraction from saturated hydrocarbons: A crossed-molecular-beams study of the reaction Cl + C{sub 3}H{sub 8} {yields} HCl + C{sub 3}H{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Blank, D.A.; Hemmi, N.; Suits, A.G.; Lee, Y.T. [Lawrence Berkeley National Lab., CA (United States)

1997-04-01

The abstraction of hydrogen atoms from saturated hydrocarbons are reactions of fundamental importance in combustion as well as often being the rate limiting step in free radical substitution reactions. The authors have begun studying these reactions under single collision conditions using the crossed molecular beam technique on beamline 9.0.2.1, utilizing VUV undulator radiation to selectively ionize the scattered hydrocarbon free radical products (C{sub x}H{sub 2x+1}). The crossed molecular beam technique involves two reactant molecular beams fixed at 90{degrees}. The molecular beam sources are rotatable in the plane defined by the two beams. The scattered neutral products travel 12.0 cm where they are photoionized using the VUV undulator radiation, mass selected, and counted as a function of time. In the authors initial investigations they are using halogen atoms as protypical free radicals to abstract hydrogen atoms from small alkanes. Their first study has been looking at the reaction of Cl + propane {r_arrow} HCl + propyl radical. In their preliminary efforts the authors have measured the laboratory scattering angular distribution and time of flight spectra for the propyl radical products at collision energies of 9.6 kcal/mol and 14.9 kcal/mol.

Wear behavior of A356/M{sub 7}C{sub 3} and A356/SiC particulate metal matrix composites

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Turhan, H. [Univ. of Firat, Dept. of Metallurgy, Elazig (Turkey); Yilmaz, O. [Univ. of Firat, Dept. of Metallurgical Engineering, Elazig (Turkey)

2002-06-01

The stability of M{sub 7}C{sub 3} carbides as reinforcement for A356 materials for tribological applications has been investigated. For this purpose, A356/M{sub 7}C{sub 3}, A356/SiC and A356/M{sub 7}C{sub 3}/SiC composites were prepared by powder metallurgy and tested at room temperature against SAE 4620 steel ring and AISI 304 stainless steel counterfaces under loads of 10 - 150 N. For comparison, also unreinforced A356 specimens were processed and tested under the same conditions. The tribological behavior was evaluated by microstructural examination of the wear-effected zones and by weight loss measurements of the specimens and counterfaces. The wear behavior of A356/M{sub 7}C{sub 3} composite gave an excellent result as function of the applied load because the M{sub 7}C{sub 3} particles act as load-bearing elements due to their excellent bonding to the Al matrix, and their interfaces withtood the wear stresses even at the highest applied load. Moreover, the M{sub 7}C{sub 3} particles limited the incorporation of wear debris into the Al matrix and reduced the wear damage occasioned to the steel counterfaces compared to that of A356 Al alloy. (orig.)

Effect of glycolate on the activity of ribulosediphosphate and phosphoenolpyruvate carboxylases in C/sub 3/ and C/sub 4/ plants at different O/sub 2/ concentrations

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Popova, L; Dimitrova, O [Bylgarska Akademiya na Naukite, Sofia. Inst. po Fiziologiya na Rasteniyata

1981-01-01

The experiments are carried out with pisum and maize plants grown in a chamber under controlled conditions. The activity of the two enzymes is recorded by the amount of fixed H/sup 14/CO/sub 3/ in acid-stable products of the reactions. The effect of glycolate on the activity of the carboxylating enzymes is largely related to the effect of O/sub 2/ on the activity of the RuDP and PEP carboxylases. The stimulating effect of glucolate on the activity of the carboxylating enzymes is probably of a regulatory significance. An essential conclusion is that O/sub 2/ attacks C/sub 4/ photosynthesis not only on inhibiting the RuDP carboxylase in bundle sheath cells, but it also inhibits the activity of the main carboxylating enzyme in C/sub 4/ plants-the PEP carboxylase.

Cloning, DNA sequence, and expression of the Rhodobacter sphaeroides cytochrome c/sub 2/ gene

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Donohue, T.J.; McEwan, A.G.; Kaplan, S.

1986-11-01

The Rhodobacter sphaeroides cytochrome c/sub 2/ functions as a mobile electron carrier in both aerobic and photosynthetic electron transport chains. Synthetic deoxyoligonucleotide probes, based on the known amino acid sequence of this protein (M/sub r/ 14,000), were used to identify and clone the cytochrome c/sub 2/ structural gene (cycA). DNA sequence analysis of the cycA gene indicated the presence of a typical procaryotic 21-residue signal sequence, suggesting that this periplasmic protein is synthesized in vivo as a precursor. Synthesis of an immunoreactive cytochrome c/sub 2/ precursor protein (M/sub r/ 15,500) was observed in vitro when plasmids containing the cycA gene were used as templates in an R. sphaeroides coupled transcription-translation system. Approximately 500 base pairs of DNA upstream of the cycA gene was sufficient to allow expression of this gene product in vitro. Northern blot analysis with an internal cycA-specific probe identified at least two possibly monocistronic transcripts present in both different cellular levels and relative stoichiometries in steady-state cells grown under different physiological conditions. The ratio of the small (740-mucleotide) and large (920-nucleotide) cycA-specific mRNA species was dependent on cultural conditions but was not affected by light intensity under photosynthetic conditions. These results suggest that the increase in the cellular level of the cytochrome c/sub 2/ protein found in photosynthetic cells was due, in part, to increased transcription of the single-copy cyc operon.

Development of Cr{sub 3}C{sub 2}-25(Ni20Cr) nanostructured coatings; Desenvolvimento de revestimentos nanostruturados de Cr{sub 3}C{sub 2}-25(Ni20Cr)

Energy Technology Data Exchange (ETDEWEB)

Cunha, Cecilio Alvares da

2012-07-01

This study is divided in two parts. The first part is about the preparation of nanostructured Cr{sub 3}C{sub 2}-25(Ni20Cr) powders by high energy milling followed by characterization of the milled and the as received powder. Analyses of some of the data obtained were done using a theoretical approach. The second part of this study is about the preparation and characterization of coatings prepared with the nanostructured as well as the as received Cr{sub 3}C{sub 2}-25(Ni20Cr) powders. The high temperature erosion-oxidation (E-O) behavior of the coatings prepared with the two types of powders has been compared based on a technological approach. The average crystallite size of the Cr{sub 3}C{sub 2}-25(Ni20Cr) powder decreased rapidly from 145 nm to 50 nm in the initial stages of milling and thereafter decreased slowly to a steady state value of around 10 nm with further increase in milling time. This steady state corresponds to the beginning of a dynamic recovery process. The maximum lattice strain ({epsilon} = 1,17%) was observed in powders milled for 16 hours, and this powders critical crystallite size was 28 nm. In contrast, the lattice parameter attained a minimum for powders milled for 16 hours. Upon reaching the critical crystallite size, the dislocation density attained a steady state regime and all plastic deformation introduced in the material there after was in the form of events occurring at the grain boundaries, due mainly to grain boundary sliding. The deformation energy stored in the crystal lattice of the Cr{sub 3}C{sub 2}-25(Ni20Cr) powders milled for different times was determined from enthalpy variation measurements. These results indicated that the maximum enthalpy variation ({delta}H = 722 mcal) also occurred for powders milled for 16 hours. In a similar manner, the maximum specific heat variation ({delta}C{sub p} = 0,278 cal/gK) occurred for powders milled for 16 hours. The following mechanical properties of Cr{sub 3}C{sub 2}-25(Ni20Cr) coatings

Surface modified MXene Ti{sub 3}C{sub 2} multilayers by aryl diazonium salts leading to large-scale delamination

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Wang, Hongbing [College of Mechanics and Materials, Hohai University, Nanjing, Jiangsu Province 210098 (China); Department of Mathematics and Physics, Nanjing Institute of Technology, Nanjing, Jiangsu Province 211167 (China); Zhang, Jianfeng, E-mail: jfzhang_sic@163.com [College of Mechanics and Materials, Hohai University, Nanjing, Jiangsu Province 210098 (China); Wu, Yuping; Huang, Huajie; Li, Gaiye; Zhang, Xin; Wang, Zhuyin [College of Mechanics and Materials, Hohai University, Nanjing, Jiangsu Province 210098 (China)

2016-10-30

Highlights: • A novel and simple method to delaminate MXene Ti{sub 3}C{sub 2} multilayers. • Surface modification using aryl diazonium salts induced swelling that conversely weakened the bonds between MXene layers. • The grafting of phenylsulfonic acid groups on MXene surfaces resulted in excellent water dispersibility. - Abstract: Herein we report a simple and facile method to delaminate MXene Ti{sub 3}C{sub 2} multilayers by the assistance of surface modification using aryl diazonium salts. The basic strategy involved the preparation of layered MAX Ti{sub 3}AlC{sub 2} and the exfoliation of Ti{sub 3}AlC{sub 2} into Ti{sub 3}C{sub 2} multilayers, followed by Na{sup +} intercalation and surface modification using sulfanilic acid diazonium salts. The resulting chemically grafted Ti{sub 3}C{sub 2} flakes were characterized by Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) to confirm the presence of the surface organic species. Ultraviolet-visible spectroscopy revealed that surface-modified MXene Ti{sub 3}C{sub 2} sheets disperse well in water and the solutions obey Lambert–Beer’s law. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to demonstrate the morphology and structure of delaminating MXene Ti{sub 3}C{sub 2} flakes. The results indicated that chemical modification for MXene multilayers by aryl diazonium salts induced swelling that conversely weakened the bonds between MX layers, hence leading to large-scale delamination of multilayered MXene Ti{sub 3}C{sub 2}via mild sonication. Advantages of the present approach rely not only on the simplicity and efficiency of the delamination procedure but also on the grafting of aryl groups to MXene surfaces, highly suitable for further applications of the newly discovered two-dimensional materials.

On the Formation of the C{sub 2}H{sub 6}O Isomers Ethanol (C{sub 2}H{sub 5}OH) and Dimethyl Ether (CH{sub 3}OCH{sub 3}) in Star-forming Regions

Energy Technology Data Exchange (ETDEWEB)

Bergantini, Alexandre; Maksyutenko, Pavlo; Kaiser, Ralf I., E-mail: ralfk@hawaii.edu [Department of Chemistry, University of Hawaii at Mānoa, Honolulu, HI 96822 (United States)

2017-06-01

The structural isomers ethanol (CH{sub 3}CH{sub 2}OH) and dimethyl ether (CH{sub 3}OCH{sub 3}) were detected in several low-, intermediate-, and high-mass star-forming regions, including Sgr B2, Orion, and W33A, with the relative abundance ratios of ethanol/dimethyl ether varying from about 0.03 to 3.4. Until now, no experimental data regarding the formation mechanisms and branching ratios of these two species in laboratory simulation experiments could be provided. Here, we exploit tunable photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS) to detect and analyze the production of complex organic molecules (COMs) resulting from the exposure of water/methane (H{sub 2}O/CH{sub 4}) ices to energetic electrons. The main goal is to understand the formation mechanisms in star-forming regions of two C{sub 2}H{sub 6}O isomers: ethanol (CH{sub 3}CH{sub 2}OH) and dimethyl ether (CH{sub 3}OCH{sub 3}). The results show that the experimental branching ratios favor the synthesis of ethanol versus dimethyl ether (31 ± 11:1). This finding diverges from the abundances observed toward most star-forming regions, suggesting that production routes on interstellar grains to form dimethyl ether might be missing; alternatively, ethanol can be overproduced in the present simulation experiments, such as via radical–radical recombination pathways involving ethyl and hydroxyl radicals. Finally, the PI-ReTOF-MS data suggest the formation of methylacetylene (C{sub 3}H{sub 4}), ketene (CH{sub 2}CO), propene (C{sub 3}H{sub 6}), vinyl alcohol (CH{sub 2}CHOH), acetaldehyde (CH{sub 3}CHO), and methyl hydroperoxide (CH{sub 3}OOH), in addition to ethane (C{sub 2}H{sub 6}), methanol (CH{sub 3}OH), and CO{sub 2} detected from infrared spectroscopy. The yield of all the confirmed species is also determined.

Comparative study of the catalytic activity of the complexes Cp{sup *}RuCl(PAr{sub 3}){sub 2} [Ar = -C{sub 6H}5 and 4-CF{sub 3}-C{sub 6}H{sub 4}] in the ATRP of styrene

Energy Technology Data Exchange (ETDEWEB)

Villa-Hernandez, Alejandro M.; Rosales-Velazquez, Claudia P.; Torres-Lubian, Jose R., E-mail: rtorres@ciqa.mx [Departamento de Sintesis de Polimeros, Centro de Investigacion en Quimica Aplicada, Coah. (Mexico); Saldivar-Guerra, Enrique [Departamento de Procesos de Polimerizacion, Centro de Investigacion en Quimica Aplicada, Coah. (Mexico)

2011-09-15

Styrene polymerization by ATRP was conducted independently using the complexes Cp{sup *}RuCl(PPh{sub 3}){sub 2}, and Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2} as catalysts, in order to evaluate the influence of the electronic properties of the phosphine ligands on the rate and control of the polymerization. The kinetic data for polymerizations carried out with Cp{sup *}RuCl(PPh{sub 3}){sub 2}, show that molecular weights increase linearly with conversion with an average initiation efficiency of 0.77. The molecular weights obtained in the kinetic study with Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2} also increase with conversion but show a marked deviation below the theoretical molecular weights. This behavior was explained by the gradual, irreversible, oxidation of catalyst Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2} as confirmed by {sup 31}P-NMR spectroscopy. Catalyst Cp{sup *}RuCl(PPh{sub 3}){sub 2} promotes the polymerization with a rate of polymerization higher than that obtained using Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2}; this is consistent with the better electron donating properties of PPh{sub 3} versus P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}. Preliminary studies of styrene polymerization by ATRP in supercritical CO{sub 2}, shows that only catalyst Cp{sup *}RuCl[P(4-CF{sub 3}-C{sub 6}H{sub 4}){sub 3}]{sub 2}, with fluorinated ligands, was active. (author)

Characterization of Al–Al{sub 4}C{sub 3} nanocomposites produced by mechanical milling

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Santos-Beltrán, A., E-mail: asantos@utchsur.edu.mx [Universidad Tecnológica de Chihuahua Sur, Carr. Chihuahua a Aldama km. 3 S/N, Col. Colinas del León, CP. 31313 Chihuahua, Chih. (Mexico); Goytia-Reyes, R. [Centro de Investigación en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, C.P. 31109 Chihuahua, Chih. (Mexico); Morales-Rodriguez, H.; Gallegos-Orozco, V. [Universidad Tecnológica de Chihuahua Sur, Carr. Chihuahua a Aldama km. 3 S/N, Col. Colinas del León, CP. 31313 Chihuahua, Chih. (Mexico); Santos-Beltrán, M. [Centro de Investigación en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, C.P. 31109 Chihuahua, Chih. (Mexico); Baldenebro-Lopez, F. [Universidad Tecnológica de Chihuahua Sur, Carr. Chihuahua a Aldama km. 3 S/N, Col. Colinas del León, CP. 31313 Chihuahua, Chih. (Mexico); Martínez-Sánchez, R. [Centro de Investigación en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, C.P. 31109 Chihuahua, Chih. (Mexico)

2015-08-15

In this work, a mixture of Al–C–Al{sub 4}C{sub 3} nanopowder previously synthesized by mechanical milling and subsequent thermal treatment was used to reinforce the Al matrix. The nanocomposites were fabricated via high-energy ball milling and subsequent sintering process for different periods of time at 550 °C. Hardness and compression tests were performed to evaluate the mechanical properties of the nanocomposites in the as-milled and sintered conditions. According to the results the reinforcement located in the grain boundaries is responsible for the brittle behavior observed in the nanocomposites during the compression test. The combined effect of sintering and precipitation mechanisms produced an evident increase of the strength of the Al matrix at a relatively short sintering time. By using the Rietveld method the crystallite size and microstrain measurements were determined and correlated with the microhardness values. For the proper characterization of the nanoparticles present in the Al matrix, atomic force microscopy and high resolution electron microscopy were used. - Highlights: • Nanostructured Al{sub 4}C{sub 3} reinforcement was fabricated via mechanical milling and heat treatment. • We found a significant increase of the mechanical properties at short sintering times. • The formation of Al{sub 4}C{sub 3} with during sintering time restricted the excessive growth of the crystallite. • Al{sub 4}C{sub 3} located in the grain boundaries causes brittle fracture observed in compression tests. • There is a correlation between, crystallite size and microstrain values with microhardness.

Quantum-chemical ab initio calculations on the three isomers of diborabenzene (C{sub 4}H{sub 4}B{sub 2})

Energy Technology Data Exchange (ETDEWEB)

Singh, Jaswinder; Raabe, Gerhard [Inst. fuer Organische Chemie, RWTH Aachen Univ. (Germany); Wang Yuekui [Key Lab. of Chemical Biology and Molecular Engineering of the Education Ministry, Inst. of Molecular Science, Shanxi Univ., Taiyuan, SH (China)

2010-01-15

Quantum-chemical ab initio calculations up to the ZPE+CCSD(T)/aug-cc-pVTZ/MP2/6-311++G** level were performed on three possible structural isomers of diborabenzene (C{sub 4}H{sub 4}B{sub 2}). All three molecules were found to be local minima on the C{sub 4}H{sub 4}B{sub 2} energy surface and to have closed shell singlet ground states. While the ground states of the 1,3- and 1,4-isomer are planar and of C{sub 2v} and D{sub 2h} symmetry, respectively, 1,2-diborabenzene is non-planar with a C{sub 2} axis passing through the center of the BB bond and the middle of the opposite carbon-carbon bond as the only symmetry element. The energetically most favourable 1,3-diborabenzene was found to be about 19 and 36 kcal/mol lower in energy than the 1,2- and the 1,4-isomer. Planar 1,3- and 1,4-diborabenzene have three doubly occupied {pi} orbitals while non-planar 1,2-diborabenzene has also three doubly occupied orbitals which can be derived from the {pi} orbitals of its 3.7 kcal/mol energetically less favourable planar form (''{pi}=like'' orbitals). The lowest unoccupied orbitals of all three isomers have {sigma} symmetry with large coefficients at the two boron atoms. These orbitals are lower in energy than the lowest unoccupied molecular orbitals (LUMOs) of e. g. benzene and pyridine and might cause pronounced acceptor properties which could be one of the reasons for the elusiveness of the title compounds. The results of bond separation reactions show that cyclic conjugation stabilizes all three diborabenzenes relative to their isolated fragments. The most effective stabilization energy of about 24 kcal/mol was found for the energetically lowest 1,3-isomer. This value amounts to approximately one third of the experimental value for the bond separation energy of pyridine. In all cases the energetically lowest triplet states are significantly (16 - 24 kcal/mol) higher in energy than the singlet ground states. Also among the triplets the 1,3-isomer is the

Unraveling the role of support surface hydroxyls and its effect on the selectivity of C{sub 2} species over Rh/γ-Al{sub 2}O{sub 3} catalyst in syngas conversion: A theoretical study

Energy Technology Data Exchange (ETDEWEB)

Zhang, Riguang; Duan, Tian; Wang, Baojun, E-mail: wangbaojun@tyut.edu.cn; Ling, Lixia

2016-08-30

Highlights: • The selectivity toward CH{sub x} (x = 1–3) depends on γ-Al{sub 2}O{sub 3} support and its surface properties. • Rh/γ-Al{sub 2}O{sub 3} catalyst exhibits the higher selectivity toward CH{sub x} (x = 1,2) formation from syngas. • C{sub 2} species (C{sub 2}H{sub 2},CHCO,CH{sub 2}CHO) are the main products on Rh/γ-Al{sub 2}O{sub 3} catalyst. • γ-Al{sub 2}O{sub 3} surface hydroxyls affect the selectivity of C{sub 2} species over Rh/γ-Al{sub 2}O{sub 3} catalyst. - Abstract: The supported Rh-based catalysts exhibit the excellent catalytic performances for syngas conversion to C{sub 2} species. In this study, all possible elementary steps leading to C{sub 2} species from syngas have been explored to identify the role of support and its surface hydroxyls over Rh/γ-Al{sub 2}O{sub 3} catalyst; Here, the results are obtained using density functional theory (DFT) method. Two models: Rh4 cluster supported on the dry γ-Al{sub 2}O{sub 3}(110) surface, D(Rh4), and on the hydroxylated γ-Al{sub 2}O{sub 3}(110) surface, H(Rh4), have been used to model Rh/γ-Al{sub 2}O{sub 3} catalyst. Our results show that CO prefers to be hydrogenated to CHO, subsequently, starting from CHO species, CH and CH{sub 2} species are the dominate monomers among CH{sub x}(x = 1–3) species rather than CH{sub 3} and CH{sub 3}OH on D(Rh4) and H(Rh4) surfaces, suggesting that γ-Al{sub 2}O{sub 3}-supported Rh catalyst exhibits the high selectivity towards CH{sub x} formation compared to the pure Rh catalyst. On the other hand, D(Rh4) is more favorable for C{sub 2} hydrocarbon (C{sub 2}H{sub 2}) formation, whereas H(Rh4) surface easily produces C{sub 2} hydrocarbon (C{sub 2}H{sub 2}) and C{sub 2} oxygenates (CHCO,CH{sub 2}CHO), indicating that the surface hydroxyls of support can affect the selectivity of C{sub 2} species over Rh/γ-Al{sub 2}O{sub 3} catalyst in syngas conversion. Moreover, compared to the pure Rh(111) surface, Rh/γ-Al{sub 2}O{sub 3} catalyst can achieve the

V{sub 18}P{sub 9}C{sub 2}. A complex phosphide carbide

Energy Technology Data Exchange (ETDEWEB)

Boller, Herbert [Linz Univ. (Austria). Inst. fuer Anorganische Chemie; Effenberger, Herta [Wien Univ. (Austria). Inst. fuer Mineralogie und Kristallographie

2016-08-01

V{sub 18}P{sub 9}C{sub 2} crystallizes in the orthorhombic space group Pmma with the lattice parameters a = 17.044(3), b = 3.2219(7), and c = 13.030(2) Aa, Z = 2. The crystal structure is composed of 19 symmetry-independent atoms. The crystal structure is considered as a network formed by the transition metal atoms exhibiting cubic, trigonal prismatic, and octahedral voids centered by V, P, and C atoms, respectively. Vice versa, the V and P atoms form a three-dimensional network. The two CV{sub 6} octahedra are edge- and corner-connected to chains running parallel to [010]. The five unique P atoms are trigonal prismatically coordinated by V atoms with one to three faces capped again by a V atom. The V atoms have mainly cubic environments formed solely by V or by V and P atoms. V{sub 18}P{sub 9}C{sub 2} exhibits some structural relations to other compounds of the ternary system V-P-C as well as to other intermetallic phases. Despite the low carbon content, V{sub 18}P{sub 9}C{sub 2} is considered as a ternary compound rather than an interstitially stabilized (binary) phosphide in view of its special structural features.

He/Ar-atom scattering from molecular monolayers: C{sub 60}/Pt(111) and graphene/Pt(111)

Energy Technology Data Exchange (ETDEWEB)

Yamada, Y; Sugawara, C; Satake, Y; Yokoyama, Y; Okada, R; Nakayama, T; Sasaki, M [Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki (Japan); Kondo, T; Oh, J; Nakamura, J [Institute of Material Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki (Japan); Hayes, W W [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States)

2010-08-04

Supersonic He and Ar atomic beam scattering from C{sub 60} and graphene monolayers adsorbed on a Pt(111) surface are demonstrated in order to obtain detailed insight into a gas-molecule collision that has not been studied in detail so far. The effective masses and phonon spectral densities of the monolayers seen by different projectiles are discussed based on classical models such as the hard cube model and the recently developed smooth surface model. Large effective masses are deduced for both the monolayers, suggesting collective effects of surface atoms in the single collision event. The effective Debye temperature of graphene was found to be similar to that reported in highly oriented pyrolytic graphite (HOPG), indicating that the graphene is decoupled well from the Pt substrate. A much smaller Debye-Waller factor was found for the C{sub 60} layer, probably reflecting the strong C{sub 60}-Pt(111) interaction.

Scaling of C{sub 60} ionization and fragmentation with the energy deposited in collisions with H{sup +}, H{sub 2}{sup +}, H{sub 3}{sup +} and He{sup +} ions (2-130 keV)

Energy Technology Data Exchange (ETDEWEB)

Bordenave-Montesquieu, D. [LCAR, IRSAMC, UMR 5589 CNRS, Universite Paul Sabatier, Toulouse (France)]. E-mail: dbm@yosemite.ups-tlse.fr; Moretto-Capelle, P.; Bordenave-Montesquieu, A.; Rentenier, A. [LCAR, IRSAMC, UMR 5589 CNRS, Universite Paul Sabatier, Toulouse (France)

2001-03-14

Fragmentation, ionization and C{sub 2} fragment evaporation of the C{sub 60} molecule induced by collisions with H{sup +}, H{sub 2}{sup +}, H{sub 3}{sup +} and He{sup +} monocharged ions have been measured in coincidence with the electron emission in the 2-130 keV projectile energy range. The time-of-flight mass spectra were found to vary strongly with the collision energy or velocity and the projectile. On the other hand, they scale rather nicely with the energy deposited in the molecule. Relative weights of the total multi-fragmentation into small C{sub n}{sup +} fragments (n=1-14), individual multi-fragmentation (n=1,7 and 11), double ionization of the intact molecule and evaporation of C{sub 2} molecules associated with the doubly charged fullerene ion, are used to illustrate our finding quantitatively. (author). Letter-to-the-editor.

Enhanced photoelectrochemical cathodic protection performance of the C{sub 3}N{sub 4}@In{sub 2}O{sub 3} nanocomposite with quasi-shell–core structure under visible light

Energy Technology Data Exchange (ETDEWEB)

Sun, Mengmeng; Chen, Zhuoyuan, E-mail: zychen@qdio.ac.cn; Bu, Yuyu

2015-01-05

Highlights: • The C{sub 3}N{sub 4}@In{sub 2}O{sub 3} composite with quasi-shell–core structure is prepared. • Photoelectrochemical cathodic protection performance of this composite was studied. • C{sub 3}N{sub 4} coating on In{sub 2}O{sub 3} dramatically enhances its light absorption capability. • C{sub 3}N{sub 4} coating on In{sub 2}O{sub 3} dramatically enhances its photoelectrochemical properties. • C{sub 3}N{sub 4} coating on In{sub 2}O{sub 3} dramatically enhances its electron transfer capability. - Abstract: Carbon nitride@Indium oxide (C{sub 3}N{sub 4}@In{sub 2}O{sub 3}) composite with quasi-shell–core structure was successfully prepared in this work. The photoinduced open circuit potential and current density results show that the C{sub 3}N{sub 4}@In{sub 2}O{sub 3} composite with quasi-shell–core structure could provide the optimal photoelectrochemical cathodic protection capability for 304 stainless steel under visible light when the adding amount of C{sub 3}N{sub 4} in the C{sub 3}N{sub 4}@In{sub 2}O{sub 3} composite is 3 wt%. The light absorption capability of the C{sub 3}N{sub 4}@In{sub 2}O{sub 3} composite was enhanced due to the synergistic effect of heterojunction structure. According to the HRTEM images, photoinduced Volt–Ampere characteristic curves and electrochemical impedance spectra, the ultrathin coating layer of C{sub 3}N{sub 4} on the surface of In{sub 2}O{sub 3} helps to form a heterojunction electric field at the interface between C{sub 3}N{sub 4} and In{sub 2}O{sub 3}, which enhances the separation efficiency of the photogenerated electron–hole pairs. Excessive C{sub 3}N{sub 4} will decline the photoelectrochemical cathodic protection of this composite due to the lower intrinsic electronic mobility and the lower photoelectric conversion property of C{sub 3}N{sub 4}.

A combined crossed molecular beams and theoretical study of the reaction CN + C{sub 2}H{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Balucani, Nadia, E-mail: nadia.balucani@unipg.it [Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia (Italy); Leonori, Francesca; Petrucci, Raffaele [Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia (Italy); Wang, Xingan [Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia (Italy); Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (China); Casavecchia, Piergiorgio [Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia (Italy); Skouteris, Dimitrios [Scuola Normale Superiore, Pisa (Italy); Albernaz, Alessandra F. [Instituto de Física, Universidade de Brasília, Brasília (Brazil); Gargano, Ricardo [Instituto de Física, Universidade de Brasília, Brasília (Brazil); Departments of Chemistry and Physics, University of Florida, Quantum Theory Project, Gainesville, FL 32611 (United States)

2015-03-01

Highlights: • The CN + C{sub 2}H{sub 4} reaction was investigated in crossed beam experiments. • Electronic structure calculations of the potential energy surface were performed. • RRKM estimates qualitatively reproduce the experimental C{sub 2}H{sub 3}NC yield. - Abstract: The CN + C{sub 2}H{sub 4} reaction has been investigated experimentally, in crossed molecular beam (CMB) experiments at the collision energy of 33.4 kJ/mol, and theoretically, by electronic structure calculations of the relevant potential energy surface and Rice–Ramsperger–Kassel–Marcus (RRKM) estimates of the product branching ratio. Differently from previous CMB experiments at lower collision energies, but similarly to a high energy study, we have some indication that a second reaction channel is open at this collision energy, the characteristics of which are consistent with the channel leading to CH{sub 2}CHNC + H. The RRKM estimates using M06L electronic structure calculations qualitatively support the experimental observation of C{sub 2}H{sub 3}NC formation at this and at the higher collision energy of 42.7 kJ/mol of previous experiments.

Effects of the fullerene (C{sub 60}) potential and position of the atom (A) on spectral characteristics of endohedral atoms A and C{sub 60}

Energy Technology Data Exchange (ETDEWEB)

Baltenkov, A S [Arifov Institute of Electronics, 100125 Tashkent (Uzbekistan); Becker, U [Fritz-Haber-Institute der Max-Planck-Gesellschaft, D-14195 Berlin (Germany); Manson, S T [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303 (United States); Msezane, A Z, E-mail: arkbalt@mail.r, E-mail: becker@fhi-berlin.mpg.d, E-mail: manson@phy-astr.gsu.ed, E-mail: amsezane@cau.ed [Center for Theoretical Studies of Physical Systems, Clark Atlanta University, Atlanta, GA 30314 (United States)

2010-06-14

Within the framework of a model representing the potential of a C{sub 60} cage as a spherical electro-neutral layer U(r) formed by smeared carbon atoms, the effect of the details of the potential on spectral characteristics of atoms localized inside the fullerene shell has been studied. Using examples of encapsulated H and He atoms, it is shown that for potential shell thickness not exceeding 1.3-1.5 au, confinement resonance oscillations in the photoionization cross section weakly depend on the shape of the function U(r). With increasing width of the potential well, the confinement resonances in the energy dependence of the photoionization cross section disappear. In addition, it is demonstrated that displacing the doped atom from the centre of the cavity also diminishes the amplitude of the confinement resonance.

Image quality and volume computed tomography air kerma index (C{sub vol}) evaluation in Recife; Avaliacao da qualidade de imagem e do indice volumetrico de Kerma ar em tomografia computadorizada (C{sub vol}) em Recife

Energy Technology Data Exchange (ETDEWEB)

Andrade, Marcos Ely Almeida

2008-07-01

The Computed Tomography (CT) is an important diagnostic imaging method, widely used. However, in spite of all the advantages and technologic advances within the CT scanners, the tomographic procedures result in high absorbed doses to patients. The main objective of this work was to perform a dosimetric study of CT scanners located at Recife and to evaluate the image quality on CT examinations in these equipment. The volume CT air kerma index (C{sub VOL}) and air kerma length product (P{sub KL,CT}) were estimated. These values were calculated using normalized weighted air kerma indexes in CT standard dosimetry phantoms ({sub n}C{sub W}), supplied by ImPACT group for several CT scanners, and the scan parameters of routine head, routine chest and hi-resolution chest CT exams performed at 20 institutions. The irradiation parameters of 15 adult patients for each CT procedure were registered at six participating centres, at which the phantom from the American College of Radiology (ACR) CT accreditation protocol was used for the image quality measurements. For routine head exams, the C{sub VOL} values varied between 12 and 58 mGy (at the posterior fossa) and 15 to 58 mGy (at the cerebrum) and the P{sub KL,CT}, from 150 to 750 mGy{center_dot}cm. The C{sub VOL} values for routine chest procedures varied from 3 to 26 mGy and the P{sub KL,CT}, between 120 and 460 mGy{center_dot}cm. In relation to Hi-resolution chest exams, C{sub VOL} values were from 1.0 to 2.7 mGy and the P{sub KL,CT} values varied between 24 and 67 mGy{center_dot}cm. The image quality evaluations results showed that almost all scanners presented at least one inadequacy. One of the equipment presented faults at 70% of the tests. With regard to the image noise, only two scanners presented acceptable results. From these results, it is possible to conclude that the volume CT air kerma index values are lower than the European reference levels. However, the image quality of these CT scanners does not attend the

Properties of K,Rb-intercalated C{sub 60} encapsulated inside carbon nanotubes called peapods derived from nuclear magnetic resonance

Energy Technology Data Exchange (ETDEWEB)

Mahfouz, R. [Division of Physical Sciences & Engineering, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia); Bouhrara, M. [Department of Chemistry, School of Science and Technology, Nazarbayev University, 010000 Astana, Republic of Kazakhstan (Kazakhstan); Kim, Y. [Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Wågberg, T. [Department of Physics, Umeå University, 901 87 Umeå (Sweden); Goze-Bac, C. [nanoNMRI Group, UMR5587, Université Montpellier II, Place E. Bataillon, 34095 Montpellier, Cedex 5 (France); Abou-Hamad, E., E-mail: edy.abouhamad@kaust.edu.sa [KAUST Catalysis Center (KCC) King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)

2015-09-21

We present a detailed experimental study on how magnetic and electronic properties of Rb,K-intercalated C{sub 60} encapsulated inside carbon nanotubes called peapods can be derived from {sup 13}C nuclear magnetic resonance investigations. Ring currents do play a basic role in those systems; in particular, the inner cavities of nanotubes offer an ideal environment to investigate the magnetism at the nanoscale. We report the largest diamagnetic shifts down to −68.3 ppm ever observed in carbon allotropes, which is connected to the enhancement of the aromaticity of the nanotube envelope upon intercalation. The metallization of intercalated peapods is evidenced from the chemical shift anisotropy and spin-lattice relaxation (T{sub 1}) measurements. The observed relaxation curves signal a three-component model with two slow and one fast relaxing components. We assigned the fast component to the unpaired electrons charged C{sub 60} that show a phase transition near 100 K. The two slow components can be rationalized by the two types of charged C{sub 60} at two different positions with a linear regime following Korringa behavior, which is typical for metallic system and allow us to estimate the density of sate at Fermi level n(E{sub F})

Synthesis and crystal structure of a new homoleptic tetraarylruthenium(IV) complex Ru(2,4,5-Me{sub 3}C{sub 6}H{sub 2}){sub 4}

Energy Technology Data Exchange (ETDEWEB)

Wang, Chang-Jiu; Wu, Xiu-Li; Ma, Xiu-Fang; Jia, Ai-Quan; Zhang, Qian-Feng [Anhui Univ. of Technology, Anhui (China). Inst. of Molecular Engineering and Applied Chemistry and Anhui Province Key Lab. of Metallurgy Engineering and Resources Recycling

2017-08-01

Treatment of [Ru(acac){sub 3}] (acac-=acetylacetonate) with (2,4,5-Me{sub 3}C{sub 6}H{sub 2})MgBr, followed by column chromatography in air, afforded the homoleptic tetraaryl-ruthenium(IV) complex [Ru(2,4,5-Me{sub 3}C{sub 6}H{sub 2}){sub 4}] (1) in moderate yield. The product was characterized by proton NMR spectroscopy and microanalyses. Its crystal structure has also been established by X-ray crystallography.

C/sub 4/ photosynthesis in Euphorbia degeneri and E. remyi: a comparison of photosynthetic carbon metabolism in leaves, callus cultures and regenerated plants

Energy Technology Data Exchange (ETDEWEB)

Ruzin, S.E.

1984-04-01

Based on analysis of /sup 14/CO/sub 2/ fixation kinetics and assays of enzymes related to C/sub 4/ metabolism (NAD-ME, NADP-ME, NAD-MDH, NADP-MDH, AST, ALT), leaves and regenerated plants of Euphorbia degeneri exhibit a modified NADP-ME-type photosynthesis. Apparently, both aspartate and malate are used for transport of CO/sub 2/ to bundle sheath cells. Callus grown on either non-shoot-forming or shoot-forming media fixes CO/sub 2/ into RPP-cycle intermediates and sucrose, as well as malate and aspartate. /sup 14/CO/sub 2/ pulse/chase kinetics show no significant loss of label from C/sub 4/ acids throughout a one minute chase. Analysis of PEPCase revealed the presence of 2 isoenzymes in both leaf and regenerated plant tissues (K/sub m/ (PEP) = 0.080 and 0.550) but only one isoenzyme in callus (K/sub m/ = 0.100). It appears that C/sub 4/ photosynthesis does not occur in callus derived from this C/sub 4/ dicot but is regenerated concomitant with shoot regeneration, and ..beta..-carboxylation of PEP in callus, mediated by the low K/sub m/ isoenzyme of PEPCase, produces C/sub 4/ acids that are not involved in the CO/sub 2/ shuttle mechanism characteristic of C/sub 4/ photosynthesis. 161 references, 19 figures, 12 tables.

Prevalence, care-seeking, and health service utilization for non-communicable diseases among Syrian refugees and host communities in Lebanon.

Science.gov (United States)

Doocy, Shannon; Lyles, Emily; Hanquart, Baptiste; Woodman, Michael

2016-01-01

Given the large burden of non-communicable diseases (NCDs) among both Syrian refugees and the host communities within which they are settled, humanitarian actors and the government of Lebanon face immense challenges in addressing health needs. This study assessed health status, unmet needs, and utilization of health services among Syrian refugees and host communities in Lebanon. A cross-sectional survey of Syrian refugees and host communities in Lebanon was conducted using a two-stage cluster survey design with probability proportional to size sampling. To obtain information on chronic NCDs, respondents were asked a series of questions about hypertension, cardiovascular disease, diabetes, chronic respiratory disease, and arthritis. Differences in household characteristics by care-seeking for these conditions were examined using chi-square, t-test, and adjusted logistic regression methods. Over half (50.4 %) of refugee and host community households (60.2 %) reported a member with one of the five NCDs. Host community prevalence rates were significantly higher than refugees for all conditions except chronic respiratory diseases ( p  = 0.08). Care-seeking for NCDs among refugees and host community households was high across all conditions with 82.9 and 97.8 %, respectively, having sought care in Lebanon for their condition. Refugees utilized primary health care centers (PHCC) (57.7 %) most often while host communities sought care most in private clinics (62.4 %). Overall, 69.7 % of refugees and 82.7 % of host community members reported an out-of-pocket consultation payment ( p  = 0.041) with an average payment of US$15 among refugees and US$42 for the host community ( p Syrian crisis and the burden on the Lebanese health system, implications for both individuals with NCDs and Lebanon's health system are immense. The burden of out of pocket expenses on persons with NCDs are also substantial, especially given the tenuous economic status of many refugees

C{sub 60} fullerene decoration of carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Demin, V. A., E-mail: victordemin88@gmail.com [Russian Academy of Sciences, Emanuel Institute of Biochemical Physics (Russian Federation); Blank, V. D.; Karaeva, A. R.; Kulnitskiy, B. A.; Mordkovich, V. Z. [Technological Institute for Superhard and Novel Carbon Materials (Russian Federation); Parkhomenko, Yu. N. [National University of Science and Technology MISiS (Russian Federation); Perezhogin, I. A.; Popov, M. Yu. [Technological Institute for Superhard and Novel Carbon Materials (Russian Federation); Skryleva, E. A. [National University of Science and Technology MISiS (Russian Federation); Urvanov, S. A. [Technological Institute for Superhard and Novel Carbon Materials (Russian Federation); Chernozatonskii, L. A. [Russian Academy of Sciences, Emanuel Institute of Biochemical Physics (Russian Federation)

2016-12-15

A new fully carbon nanocomposite material is synthesized by the immersion of carbon nanotubes in a fullerene solution in carbon disulfide. The presence of a dense layer of fullerene molecules on the outer nanotube surface is demonstrated by TEM and XPS. Fullerenes are redistributed on the nanotube surface during a long-term action of an electron beam, which points to the existence of a molecular bond between a nanotube and fullerenes. Theoretical calculations show that the formation of a fullerene shell begins with the attachment of one C{sub 60} molecule to a defect on the nanotube surface.

A C{sub 2}-symmetric ratiometric fluorescence and colorimetric anion sensor based on pyrrole derivative

Energy Technology Data Exchange (ETDEWEB)

Liu Ge [Department of Chemistry, Chifeng University, Chifeng 024000 (China); Shao Jie, E-mail: njshao@live.c [Department of Chemistry and Materials Science, Nanjing Forestry University, Nanjing 210037 (China)

2011-07-15

A C{sub 2}-symmetric fluorescence and colorimetric anion sensor (1) based on pyrrole derivative was designed and synthesized according to binding site-signaling subunit approach. The compound 1 was easily prepared by reaction of pyrrole-2,5-dicarboxaldehyde with 4-nitrophenylhydrazine in ethanol (yield=78%). In DMSO, the sensor 1 exhibited a visible color change from red to brown upon exposure to anions such as AcO{sup -} and F{sup -}; however, no obvious color changes were observed when the other tested anions (e. g. H{sub 2}PO{sub 4}{sup -}, Cl{sup -}, Br{sup -} and I{sup -}) were added. There was a significant redshift ({Delta}{lambda}{sub max}=160 nm) in UV-vis spectrum during UV-vis spectral titrations. In particular, the sensor 1 showed ratiometric fluorescence responses to anions. - Highlights: {yields} C{sub 2}-symmetric fluorescence and colorimetric anion sensor based on pyrrole derivative was designed and synthesized according to binding site-signaling subunit approach. {yields} The sensor was easily prepared by reaction of pyrrole-2,5-dicarboxaldehyde with 4-nitrophenylhydrazine in ethanol (yield=78%). {yields} In DMSO, the sensor exhibited a visible color change from red to brown upon exposure to anions such as AcO{sup -} and F{sup -}, however, no obvious color changes were observed when the other anions tested (e. g. H{sub 2}PO{sub 4}{sup -}, Cl{sup -}, Br{sup -} and I{sup -}) were added. {yields} The sensor showed ratiometric fluorescence responses to anions.

Perturbative determination of c{sub sw} for plaquette and Symanzik gauge action and stout link clover fermions

Energy Technology Data Exchange (ETDEWEB)

Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics; Perlt, H.; Schiller, A. [Leipzig Univ. (Germany). Inst. fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Division, Dept. of Mathematical Sicences; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2008-06-15

Using plaquette and Symanzik improved gauge action and stout link clover fermions we determine the improvement coefficient c{sub SW} in one-loop lattice perturbation theory from the off-shell quark-quark-gluon three-point function. In addition, we compute the coefficients needed for the most general form of quark field improvement and present the one-loop result for the critical hopping parameter {kappa}{sub c}. We discuss mean field improvement for c{sub SW} and {kappa}{sub c} and the choice of the mean field coupling for the actions we have considered. (orig.)

A new series of oxycarbonate superconductors (Cu{sub 0.5}C{sub 0.5}){sub m}Ba{sub m+1}Ca{sub n-1}Cu{sub n}O{sub 2}({sub m+n})+1

Energy Technology Data Exchange (ETDEWEB)

Takayama-Muromachi, E.; Kawashima, T.; Matsui, Y. [National Institute for Research in Inorganic Materials, Ibaraki (Japan)

1994-12-31

We found a new series of oxycarbonate superconductors in the Ba-Ca-Cu-C-O system under high pressure of 5 GPa. Their ideal formula is (Cu{sub 0.5}C{sub 0.5}){sub m}Ba{sub m+1}Ca{sub n-1}Cu{sub n}O{sub 2}({sub m+n})+1 ((Cu,C)-m(m+1)(n-1)n). Thus far, n=3, 4 members of the m=1 series, (Cu,C)-1223 and (Cu,C)-1234, have been prepared in bulk while n=4, 5 members, (Cu,C)-2334 and (Cu,C)-2345, have been prepared for the m=2 series. (Cu,C)-1223 shows superconductivity below 67 K while T{sub c}`s of other compounds are above 110 K. In particular, (Cu,C)=1234 has the highest T{sub c} of 117 K.

Analysis of fragment size distributions in collisions of monocharged ions with the C{sub 60} molecule

Energy Technology Data Exchange (ETDEWEB)

Rentenier, A; Moretto-Capelle, P; Bordenave-Montesquieu, D; Bordenave-Montesquieu, A [LCAR-IRSAMC, UMR 5589 Universite Paul Sabatier-CNRS, 118 rte de Narbonne, 31062 Toulouse Cedex (France)

2005-04-14

Fragmentation of the C{sub 60} molecule is investigated using a multicorrelation technique. We first focus on the transition from asymmetrical dissociation (AD) to multifragmentation (MF). These processes are studied in collisions between H{sup +}{sub x}(x = 1-3) hydrogenic projectiles and C{sub 60} fullerene in the gas phase, in the 2-130 keV collisional energy range. A rather sharp transition from pure AD to predominant MF is observed when plotting the AD/(AD + MF) ratio against the average deposited energy E{sub dep}; it occurs in the 80-240 eV E{sub dep} range; this ratio is also found to be independent of the projectile species (scaling law). The evolution of the size distribution shape is also discussed and compared with other data available in the literature. A pure power law is never reached in the present experimental conditions. Finally, an event-by-event analysis of the fragmentation data is developed for the first time in the study of the C{sub 60} molecule fragmentation and discussed in terms of the predictions of the percolation model near a critical behaviour. Moments of order 2, 3 and 5 are determined for each correlation event. Moments of order 3 and 5 follow a linear behaviour when plotted against the moment of order 2, as predicted, and the exponent {tau} that is extracted takes a value near 2. The Campi scatter plot is also determined and discussed for total and multiplicity-selected events. Both slopes of the two branches in the Campi plots and {tau} value are near those that are expected in the percolation of a 2D lattice.

Synthesis, single-crystal structure determination and Raman spectra of the tricyanomelaminates NaA{sub 5}[C{sub 6}N{sub 9}]{sub 2} . 4 H{sub 2}O (A = Rb, Cs)

Energy Technology Data Exchange (ETDEWEB)

Reckeweg, Olaf; DiSalvo, Francis J. [Cornell Univ., Ithaca, NY (United States). Baker Lab.; Schulz, Armin [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

2016-07-01

Transparent colorless crystals of NaA{sub 5}[C{sub 6}N{sub 9}]{sub 2} . 4 H{sub 2}O (A = Rb, Cs) were obtained by blending aqueous solutions of Na{sub 3}[C{sub 6}N{sub 9}] and RbF or CsF, respectively, and subsequent evaporation of the water under ambient conditions. Both compounds crystallize in the space group P2{sub 1}/m (no. 11) with the cell parameters a = 815.56(16), b = 1637.7(4) and c = 1036.4(3) pm, and β = 110.738(12) for NaRb{sub 5}[C{sub 6}N{sub 9}]{sub 2} . 4 H{sub 2}O and a = 843.32(6), b = 1708.47(11) and c = 1052.42(7) pm, and β = 112.034(2) for NaCs{sub 5}[C{sub 6}N{sub 9}]{sub 2} . 4 H{sub 2}O, respectively. Raman spectra of the title compounds complement our results.

Photo-induced current and its degradation in Al{sub 4}C{sub 3}/Al{sub 2}O{sub 3} (0001) grown by metalorganic chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Kim, Dohyung, E-mail: kim@ee.tokushima-u.ac.jp [Graduate School of Advanced Technology and Science, The University of Tokushima, 2-1 Minami-josanjima, Tokushima 770-8506 (Japan); Onishi, Yuya; Oki, Ryuji [Graduate School of Advanced Technology and Science, The University of Tokushima, 2-1 Minami-josanjima, Tokushima 770-8506 (Japan); Sakai, Shiro [Institute of Technology Science, The University of Tokushima, 2-1 Minami-josanjima, Tokushima 770-8506 (Japan)

2014-04-30

Al{sub 4}C{sub 3} layers have been grown on Al{sub 2}O{sub 3} (0001) by metalorganic chemical vapor deposition. Trimethylaluminum and methane were used as source materials for aluminum and carbon, respectively. Depending on the growth conditions, the growth rate was significantly changed. The most suitable growth temperature was 1150 °C. Fresh samples had a yellowish color. Peaks at 32 and 35° observed by 2θ–ω mode X-ray diffraction scans confirmed the presence of hexagonal Al{sub 4}C{sub 3}. Experiments detected photo-induced current (PIC). PIC measured at 30 V dc was observed at Al{sub 4}C{sub 3}/Al{sub 2}O{sub 3} (0001) at the 10 nA scale. PIC in Al{sub 4}C{sub 3} increased with a decrease in the irradiated wavelength. This phenomenon was also observed in absorption coefficient experiments. It was also verified that the electrical conductivity of Al{sub 4}C{sub 3} significantly deteriorated due to oxidation. PIC was also continuously reduced during Al{sub 4}C{sub 3} oxidation. After a certain period of time, it was observed that the Al{sub 4}C{sub 3} layer separated from the Al{sub 2}O{sub 3} (0001) substrate. These results suggest that PIC can be useful in photodetectors that can be used in vacuum or in other gases that do not contain oxygen. - Highlights: • Al{sub 4}C{sub 3} layers had been grown on Al{sub 2}O{sub 3} (0001) by metalorganic chemical vapor deposition. • The growth rate abruptly increased above the temperature of 1100 °C. • Photo-induced current (PIC) was observed when the light was incident of the devices. • PIC was unrelated to the presence of a metal–semiconductor junction. • PIC was decreased during Al{sub 4}C{sub 3} oxidation process.

Effects of carbon nanomaterials fullerene C{sub 60} and fullerol C{sub 60}(OH){sub 18-22} on gills of fish Cyprinus carpio (Cyprinidae) exposed to ultraviolet radiation

Energy Technology Data Exchange (ETDEWEB)

Socoowski Britto, Roberta; Longaray Garcia, Marcia; Martins da Rocha, Alessandra [Universidade Federal do Rio Grande - FURG, Instituto de Ciencias Biologicas, Campus Carreiros, Av. Italia km 8 s/n, Rio Grande, RS (Brazil); Programa de Pos Graduacao em Fisiologia Animal Comparada - Fisiologia Animal Comparada, FURG (Brazil); Artigas Flores, Juliana [Universidade Federal do Rio Grande - FURG, Instituto de Ciencias Biologicas, Campus Carreiros, Av. Italia km 8 s/n, Rio Grande, RS (Brazil); Pinheiro, Mauricio V. Brant [Departamento de Fisica, ICEx, Universidade Federal de Minas Gerais, MG (Brazil); Monserrat, Jose Maria [Universidade Federal do Rio Grande - FURG, Instituto de Ciencias Biologicas, Campus Carreiros, Av. Italia km 8 s/n, Rio Grande, RS (Brazil); Programa de Pos Graduacao em Fisiologia Animal Comparada - Fisiologia Animal Comparada, FURG (Brazil); Ribas Ferreira, Josencler L., E-mail: josenclerf@gmail.com [Universidade Federal do Rio Grande - FURG, Instituto de Ciencias Biologicas, Campus Carreiros, Av. Italia km 8 s/n, Rio Grande, RS (Brazil); Programa de Pos Graduacao em Fisiologia Animal Comparada - Fisiologia Animal Comparada, FURG (Brazil)

2012-06-15

In consequence of their growing use and demand, the inevitable environmental presence of nanomaterials (NMs) has raised concerns about their potential deleterious effects to aquatic environments. The carbon NM fullerene (C{sub 60}), which forms colloidal aggregates in water, and its water-soluble derivative fullerol (C{sub 60}(OH){sub 18-22}), which possesses antioxidant properties, are known to be photo-excited by ultraviolet (UV) or visible light. To investigate their potential hazards to aquatic organisms upon exposure to UV sunlight, this study analyzed (a) the in vitro behavior of fullerene and fullerol against peroxyl radicals (ROO{center_dot}) under UV-A radiation and (b) the effects of these photo-excited NMs on oxidative stress parameters in functional gills extracted from the fish Cyprinus carpio (Cyprinidae). The variables measured were the total antioxidant capacity, lipid peroxidation (TBARS), the activities of the antioxidant enzymes glutathione reductase (GR) and glutamate cysteine ligase (GCL), and the levels of the non-enzymatic antioxidant glutathione (GSH). The obtained results revealed the following: (1) both NMs behaved in vitro as antioxidants against ROO{center_dot} in the dark and as pro-oxidants in presence of UV-A, the latter effect being reversed by the addition of sodium azide, which is a singlet oxygen ({sup 1}O{sub 2}) quencher; (2) fullerene induced toxicity with or without UV-A incidence, with a significant (p < 0.05) increase in lipid peroxidation (with greater damage under illumination), a decrease in GCL activity, and the depletion of GSH stocks (under illumination), all of which were attributed to {sup 1}O{sub 2} generation; and (3) fullerol also decreased GCL activity and GSH formation (p < 0.05) but without lipid damage. The overall results show that fullerene can be toxic with or without light incidence, whereas UV radiation seems to play a key role in the environmental toxicity of carbon NMs through {sup 1}O{sub 2} formation.

Theoretical predictions and experimental studies of self-organized C{sub 60} nanoparticles in water solution and on the support

Energy Technology Data Exchange (ETDEWEB)

Prilutski, Yu.I.; Durov, S.S.; Yashchuk, V.N.; Ogul' chansky, T.Yu.; Pogorelov, V.E.; Astashkin, Yu.A. [Kievskij Gosudarstvennyj Univ. (Ukraine). Radiofizicheskij Fakul' tet; Buzaneva, E.V.; Kirghisov, Yu.D. [Department of Radiophysics, Kiev Shevchenko University, Vladimirskaya Str., 64, 252033 Kiev (Ukraine); Andrievsky, G.V. [Institute for Therapy of the Academy of Medical Sciences of Ukraine, Postysheva Str. 2a, 310116 Kharkov (Ukraine); Scharff, P. [Institut fuer Anorganische und Analytische Chemie, TU Clausthal, Paul-Ernst-Strasse 4, D-38670 Clausthal-Zellerfeld (Germany)

1999-12-01

The formation in water of highly stable hydrated clusters (I{sub h} symmetry group) and microcrystals (T{sub h} symmetry group) from C{sub 60} fullerenes is theoretically predicted using a molecular dynamics calculation. The proposed models are confirmed by the experiments on the Raman and absorption spectra of the fullerene aqueous solution. The additional study of the structure of C{sub 60} fullerene aggregates in the dry layer on the support (dielectric/semiconductor) is also performed. (orig.)

Host-to-host variation of ecological interactions in polymicrobial infections

Science.gov (United States)

Mukherjee, Sayak; Weimer, Kristin E.; Seok, Sang-Cheol; Ray, Will C.; Jayaprakash, C.; Vieland, Veronica J.; Swords, W. Edward; Das, Jayajit

2015-02-01

Host-to-host variability with respect to interactions between microorganisms and multicellular hosts are commonly observed in infection and in homeostasis. However, the majority of mechanistic models used to analyze host-microorganism relationships, as well as most of the ecological theories proposed to explain coevolution of hosts and microbes, are based on averages across a host population. By assuming that observed variations are random and independent, these models overlook the role of differences between hosts. Here, we analyze mechanisms underlying host-to-host variations of bacterial infection kinetics, using the well characterized experimental infection model of polymicrobial otitis media (OM) in chinchillas, in combination with population dynamic models and a maximum entropy (MaxEnt) based inference scheme. We find that the nature of the interactions between bacterial species critically regulates host-to-host variations in these interactions. Surprisingly, seemingly unrelated phenomena, such as the efficiency of individual bacterial species in utilizing nutrients for growth, and the microbe-specific host immune response, can become interdependent in a host population. The latter finding suggests a potential mechanism that could lead to selection of specific strains of bacterial species during the coevolution of the host immune response and the bacterial species.

Host-to-host variation of ecological interactions in polymicrobial infections.

Science.gov (United States)

Mukherjee, Sayak; Weimer, Kristin E; Seok, Sang-Cheol; Ray, Will C; Jayaprakash, C; Vieland, Veronica J; Swords, W Edward; Das, Jayajit

2014-12-04

Host-to-host variability with respect to interactions between microorganisms and multicellular hosts are commonly observed in infection and in homeostasis. However, the majority of mechanistic models used to analyze host-microorganism relationships, as well as most of the ecological theories proposed to explain coevolution of hosts and microbes, are based on averages across a host population. By assuming that observed variations are random and independent, these models overlook the role of differences between hosts. Here, we analyze mechanisms underlying host-to-host variations of bacterial infection kinetics, using the well characterized experimental infection model of polymicrobial otitis media (OM) in chinchillas, in combination with population dynamic models and a maximum entropy (MaxEnt) based inference scheme. We find that the nature of the interactions between bacterial species critically regulates host-to-host variations in these interactions. Surprisingly, seemingly unrelated phenomena, such as the efficiency of individual bacterial species in utilizing nutrients for growth, and the microbe-specific host immune response, can become interdependent in a host population. The latter finding suggests a potential mechanism that could lead to selection of specific strains of bacterial species during the coevolution of the host immune response and the bacterial species.

CXCR1 regulates pulmonary anti-Pseudomonas host defense

Science.gov (United States)

Carevic, M.; Öz, H.; Fuchs, K.; Laval, J.; Schroth, C.; Frey, N.; Hector, A.; Bilich, T.; Haug, M.; Schmidt, A.; Autenrieth, S. E.; Bucher, K.; Beer-Hammer, S.; Gaggar, A.; Kneilling, M.; Benarafa, C.; Gao, J.; Murphy, P.; Schwarz, S.; Moepps, B.; Hartl, D.

2016-01-01

Pseudomonas aeruginosa is a key opportunistic pathogen causing disease in cystic fibrosis (CF) and other lung diseases such as chronic obstructive pulmonary disease (COPD). However, the pulmonary host defense mechanisms regulating anti-Pseudomonas aeruginosa immunity remain incompletely understood. Here we demonstrate, by studying an airway Pseudomonas aeruginosa infection model, in vivo bioluminescence imaging, neutrophil effector responses and human airway samples, that the chemokine receptor CXCR1 regulates pulmonary host defense against Pseudomonas aeruginosa. Mechanistically, CXCR1 regulated anti-Pseudomonas neutrophil responses through modulation of reactive oxygen species and interference with toll-like receptor 5 expression. These studies define CXCR1 as a novel non-canonical chemokine receptor that regulates pulmonary anti-Pseudomonas host defense with broad implications for CF, COPD and other infectious lung diseases. PMID:26950764

Effect of the structure distortion on the high photocatalytic performance of C{sub 60}/g-C{sub 3}N{sub 4} composite

Energy Technology Data Exchange (ETDEWEB)

Ma, Xiaojuan; Li, Xinru; Li, Mengmeng; Ma, Xiangchao; Yu, Lin, E-mail: yu-lin@sdu.edu.cn; Dai, Ying, E-mail: daiy60@sina.com

2017-08-31

Highlights: • The adsorption of C{sub 60} can induce an irreversible structure distortion for g-C{sub 3}N{sub 4} from flat to wrinkle. • The structure distortion of g-C{sub 3}N{sub 4} plays a crucial role in enhancing photocatalytic performances. • Stability, optical absorption and band edge all have positive correlations with wrinkle degree for g-C{sub 3}N{sub 4} monolayers. - Abstract: C{sub 60}/g-C{sub 3}N{sub 4} composite was reported experimentally to be of high photocatalytic activity in degrading organics. To investigate the underlying mechanism of high photocatalytic performance, the structural and electronic properties of g-C{sub 3}N{sub 4} monolayers with adsorbing and removing fullerene C{sub 60} are studied by means of density functional theory calculations. After 25 possible configurations examination, it is found that C{sub 60} prefers to stay upon the “junction nitrogen” with the carbon atom of fullerene being nearest to monolayers. Correspondingly, a type-I band alignment appears. Our results further demonstrate that the adsorption of C{sub 60} can lead to an irreversible structure distortion for g-C{sub 3}N{sub 4} from flat to wrinkle, which plays a crucial role in improving photocatalytic performance other than the separation of carriers at interface due to the formation of type-II heterojunctions as previous report. Compared to flat one, the light absorption of wrinkled structure shows augmented, the valence band maximum shifts towards lower position along with a stronger photo-oxidation capability. Interestingly, the results indicate that the energy, light absorption and band edge all have a particular relationship with wrinkle degree. The work presented here can be helpful to understand the mechanism behind the better photocatalytic performance for C{sub 60} modified g-C{sub 3}N{sub 4}.

Host-to-host variation of ecological interactions in polymicrobial infections

International Nuclear Information System (INIS)

Mukherjee, Sayak; Seok, Sang-Cheol; Ray, Will C; Jayaprakash, C; Vieland, Veronica J; Das, Jayajit; Weimer, Kristin E; Swords, W Edward

2015-01-01

Host-to-host variability with respect to interactions between microorganisms and multicellular hosts are commonly observed in infection and in homeostasis. However, the majority of mechanistic models used to analyze host–microorganism relationships, as well as most of the ecological theories proposed to explain coevolution of hosts and microbes, are based on averages across a host population. By assuming that observed variations are random and independent, these models overlook the role of differences between hosts. Here, we analyze mechanisms underlying host-to-host variations of bacterial infection kinetics, using the well characterized experimental infection model of polymicrobial otitis media (OM) in chinchillas, in combination with population dynamic models and a maximum entropy (MaxEnt) based inference scheme. We find that the nature of the interactions between bacterial species critically regulates host-to-host variations in these interactions. Surprisingly, seemingly unrelated phenomena, such as the efficiency of individual bacterial species in utilizing nutrients for growth, and the microbe-specific host immune response, can become interdependent in a host population. The latter finding suggests a potential mechanism that could lead to selection of specific strains of bacterial species during the coevolution of the host immune response and the bacterial species. (paper)

DNA segment containing C/sub β1/, a gene for the constant region of the β chain of the T-cell antigen receptor, was inserted into chromosome 6 in cells from one patients with human T-cell leukemia

International Nuclear Information System (INIS)

Ino, T.; Kurosawa, Y.; Yoshida, M.C.; Hirano, M.

1987-01-01

DNA rearrangements that occurred in the vicinity of T-cell antigen receptor β-chain gene clusters residing on chromosome 7 were examined in human T-cell acute lymphoblastic leukemia cells. In one patient, it was observed that, for the T-cell receptor β-chain genes, a D/sub β 1/-J/sub β2.3/ (where D is diversity and J is joining) junction was found on one chromosome, while the other chromosome kept the germ-line configuration. If this D/sub β/-J/sub β/ junction was formed by the customary deletion mechanism, the C/sub β1/ gene (where C is constant) located between the D/sub β1/ and J/sub Β2.3/ loci should have disappeared from this chromosome. The C/sub β1/ gene indeed was absent from the rearranged chromosome 7, but it was found on chromosome 6 as an inserted segment. The implications of the observations are discussed

The determination of carbon, nitrogen and oxygen in TiCsub(x)Nsub(y)Osub(z) with the Auger electron spectroscopy (AES)

International Nuclear Information System (INIS)

Schneider, H.; Nold, E.; Miller, H.T.

1980-01-01

The possibility of determining the carbon, nitrogen and oxygen contents in TiCsub(x)Nsub(y)Osub(z) with the Auger-electron-spectroscopy (AES) is discussed. As an example the concentration dependence over the cross section of 1 μm thick TiN-layers is presented. (orig.)

Phase transitions of doped carbon in CrCN coatings with modified mechanical and tribological properties via filtered cathodic vacuum arc deposition

Energy Technology Data Exchange (ETDEWEB)

Guan, J.J. [Faculty of Materials and Energy, Southwest University, Chongqing 400715 (China); Wang, H.Q. [College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Qin, L.Z., E-mail: qin8394@163.com [Faculty of Materials and Energy, Southwest University, Chongqing 400715 (China); Liao, B.; Liang, H. [College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Li, B. [Faculty of Materials and Energy, Southwest University, Chongqing 400715 (China)

2017-04-15

The CrCN coatings were fabricated onto Si (1 1 1) wafers and SUS304 stainless steel plates using filtered cathodic vacuum arc deposition (FCVAD) technique under different flow ratios of N{sub 2}/C{sub 2}H{sub 2} gas mixture. The morphology, crystalline structure and chemical composition of the coatings were characterized. It was found that the grain size reduce with increasing carbon content, which makes the CrCN coatings refined and smooth. The quasi-one-dimensional carbolite phase was also found in CrN host lattice with C{sub 2}H{sub 2} content ranging from 5% to 20%, and it will be evolved into amorphous carbon and amorphous CN{sub x} phases as C{sub 2}H{sub 2} content exceeds 20%. Moreover, we examined the mechanical and tribological properties of the CrCN coatings, and the experimental results confirmed that the friction coefficient of the coatings descend to the lowest value as 0.39 with 30% C{sub 2}H{sub 2} content, due to the graphite (sp{sup 2} C−C) phase embed in CrN host lattice; while the chromium carbon (Cr{sub 3}C{sub 2}) and diamond (sp{sup 3} C−C) phases may give rise to the increase of the coating hardness with the highest value at 23.97 GPa under 20% C{sub 2}H{sub 2} content.

Proteomics in the investigation of HIV-1 interactions with host proteins.

Science.gov (United States)

Li, Ming

2015-02-01

Productive HIV-1 infection depends on host machinery, including a broad array of cellular proteins. Proteomics has played a significant role in the discovery of HIV-1 host proteins. In this review, after a brief survey of the HIV-1 host proteins that were discovered by proteomic analyses, I focus on analyzing the interactions between the virion and host proteins, as well as the technologies and strategies used in those proteomic studies. With the help of proteomics, the identification and characterization of HIV-1 host proteins can be translated into novel antiretroviral therapeutics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The influence of C{sub s}/C{sub c} correction in analytical imaging and spectroscopy in scanning and transmission electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Zaluzec, Nestor J., E-mail: zaluzec@microscopy.com

2015-04-15

Aberration correction in scanning/transmission electron microscopy (S/TEM) owes much to the efforts of a small dedicated group of innovators. Leading that frontier has been Prof. Harald Rose. To date his leadership and dynamic personality has spearheaded our ability to leave behind many of the limitations imposed by spherical aberration (C{sub s}) in high resolution phase contrast imaging. Following shortly behind, has been the development of chromatic aberration correction (C{sub c}) which augments those accomplishments. In this paper we will review and summarize how the combination of C{sub s}/C{sub c} technology enhances our ability to conduct hyperspectral imaging and spectroscopy in today's and future computationally mediated experiments in both thin as well as realistic specimens in vacuo and during in-situ/environmental experiments.

Novel host restriction factors implicated in HIV-1 replication.

Science.gov (United States)

Ghimire, Dibya; Rai, Madhu; Gaur, Ritu

2018-04-01

Human immunodeficiency virus-1 (HIV-1) is known to interact with multiple host cellular proteins during its replication in the target cell. While many of these host cellular proteins facilitate viral replication, a number of them are reported to inhibit HIV-1 replication at various stages of its life cycle. These host cellular proteins, which are known as restriction factors, constitute an integral part of the host's first line of defence against the viral pathogen. Since the discovery of apolipoprotein B mRNA-editing enzyme 3G (APOBEC3G) as an HIV-1 restriction factor, several human proteins have been identified that exhibit anti-HIV-1 restriction. While each restriction factor employs a distinct mechanism of inhibition, the HIV-1 virus has equally evolved complex counter strategies to neutralize their inhibitory effect. APOBEC3G, tetherin, sterile alpha motif and histidine-aspartate domain 1 (SAMHD1), and trim-5α are some of the best known HIV-1 restriction factors that have been studied in great detail. Recently, six novel restriction factors were discovered that exhibit significant antiviral activity: endoplasmic reticulum α1,2-mannosidase I (ERManI), translocator protein (TSPO), guanylate-binding protein 5 (GBP5), serine incorporator (SERINC3/5) and zinc-finger antiviral protein (ZAP). The focus of this review is to discuss the antiviral mechanism of action of these six restriction factors and provide insights into the probable counter-evasion strategies employed by the HIV-1 virus. The recent discovery of new restriction factors substantiates the complex host-pathogen interactions occurring during HIV-1 pathogenesis and makes it imperative that further investigations are conducted to elucidate the molecular basis of HIV-1 replication.

Magnetic susceptibility and zone structure of solid solutions in ZrC-NbN and Zrsub(0.5)Nbsub(0.5)Csub(x)Nsub(1-x) systems

International Nuclear Information System (INIS)

Gusev, A.I.; Dubrovskaya, L.B.; Shvejkin, G.P.

1975-01-01

Face-centered cubic solid solutions in the systems ZrC-NbN and Zrsub(0.5)Nbsub(0.5)Csub(x)Nsub(1-x) arranged to the mutual substitution type have been synthesized. The concentration and temperature dependences of the magnetic susceptibility have been studied. The extremal nature of the concentrational dependences of the magnetic susceptibility and the magnetic susceptibility temperature coefficient in the system ZrC-NbN is determined. The possibility is shown of considering the stoichiometric carbides and nitrides of the transition metals of the same period within the framework of the model of a single zone structure

Kinetic energies of charged fragments resulting from multifragmentation and asymmetric fission of the C{sub 60} molecule in collisions with monocharged ions (2-130 keV)

Energy Technology Data Exchange (ETDEWEB)

Rentenier, A; Bordenave-Montesquieu, D; Moretto-Capelle, P; Bordenave-Montesquieu, A [Laboratoire CAR-IRSAMC, UMR 5589 CNRS - Universite Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse Cedex (France)

2003-04-28

Multifragmentation and asymmetric fission (AF) of the C{sub 60} molecule induced by H{sup +}, H{sub 2}{sup +}, H{sub 3}{sup +} and He{sup +} ions at medium collision energies (2-130 keV) are considered. Momenta and kinetic energies of C{sub n}{sup +} fragment ions (n = 1- 12) are deduced from an analysis of time-of-flight spectra. In multifragmentation processes, momenta are found to be approximately constant when n > 2, a behaviour which explains that the most probable kinetic energy, as well as the width of the kinetic energy distributions, is found to be inversely proportional to the fragment size n; both momenta and kinetic energies are independent of the velocity and nature of the projectile, and hence of the energy deposit. A specific study of the AF shows that the kinetic energies of C{sub 2}{sup +}, C{sub 4}{sup +} and C{sub 6}{sup +} fragments are also independent of the collision velocity and projectile species; a quantitative agreement is found with values deduced from kinetic energy release measurements by another group in electron impact experiments, and the observed decrease when the mass of the light fragment increases is also reproduced. A quantitative comparison of AF and multifragmentation for the n = 2, 4 and 6 fragment ions shows that kinetic energies in AF exceed that in multifragmentation, a result which explains the oscillations observed when momenta or kinetic energies of fragments are plotted against the n-value. The AF yield is also found to scale with the energy deposit in the collision velocity range extending below the velocity at the maximum of the electronic stopping power; except for protons, it remains negligible with respect to multifragmentation as soon as the total energy deposit exceeds about 100 eV.

The carbide M{sub 7}C{sub 3} in low-temperature-carburized austenitic stainless steel

Energy Technology Data Exchange (ETDEWEB)

Ernst, Frank, E-mail: frank.ernst@cwru.edu [Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, OH 44106-7204 (United States); Li, Dingqiang; Kahn, Harold; Michal, Gary M.; Heuer, Arthur H. [Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, OH 44106-7204 (United States)

2011-04-15

Prolonged low-temperature gas-phase carburization of AISI 316L-type austenitic stainless steel can cause intragranular precipitation of the carbide M{sub 7}C{sub 3} (M: randomly dispersed Fe, Cr, Ni). Transmission electron microscopy revealed that the carbide particles have the shape of needles. They grow by a ledge-migration mechanism and in a crystallographic orientation relationship to the austenite matrix that enables highly coherent interphase interfaces. A small solubility limit of Ni in the carbide and restricted Ni diffusivity at the processing temperature leads to Ni pileup around the particles and may explain the extreme aspect ratio of the particle shape. These characteristics closely resemble what has been observed earlier for precipitates of M{sub 5}C{sub 2} under slightly different processing conditions and can be rationalized by considering the particular constraints imposed by carburization at low temperature.

Absolute number density and kinetic analysis of CF, CF{sub 2} and C{sub 2}F{sub 4} molecules in pulsed CF{sub 4}/H{sub 2} rf plasmas

Energy Technology Data Exchange (ETDEWEB)

Stepanov, Sergey

2010-04-26

Tunable Diode Laser Absorption Spectroscopy in the mid InfraRed spectral range (IR-TDLAS) has been applied to investigate the behaviour of CF, CF{sub 2} and C{sub 2}F{sub 4} species produced in pulsed CF{sub 4}/H{sub 2} capacitively coupled radio frequency plasmas (13.56 MHz CCP). This experimental technique was shown to be suitable for temporally resolved measurements of the absolute number density of the target molecules in the studied fluorocarbon discharges. The temporal resolution of about 20..40 ms typically achieved in the standard data acquisition mode (''stream mode'') was sufficient for the real-time measurements of CF{sub 2} and C{sub 2}F{sub 4}, but not of CF whose kinetics was observed to be much faster. Therefore, a more sophisticated approach (''burst mode'') providing a temporal resolution of 0.94 ms was established and successfully applied to CF density measurements. In order to enable the TDLAS measurements of the target species, preliminary investigations on their spectroscopic data had been carried out. In particular, pure C{sub 2}F{sub 4} has been produced in laboratory by means of vacuum thermal decomposition (pyrolysis) of polytetrafluoroethylene and used as a reference gas. Therefore, an absorption structure consisting of several overlapping C{sub 2}F{sub 4} lines around 1337.11 cm{sup -1} was selected and carefully calibrated, which provided the first absolute measurements of the species by means of the applied experimental technique. The absolute number density traces measured for CF, CF{sub 2} and C{sub 2}F{sub 4} in the studied pulsed plasmas were then analysed, in which two differential balance equations were proposed for each of the species to describe their behaviour during both ''plasma on'' and ''plasma off'' phases. Analytical solutions of the balance equations were used to fit the experimental data and hence to deduce important information on the

Absolute number density and kinetic analysis of CF, CF{sub 2} and C{sub 2}F{sub 4} molecules in pulsed CF{sub 4}/H{sub 2} rf plasmas

Energy Technology Data Exchange (ETDEWEB)

Stepanov, Sergey

2010-04-26

Tunable Diode Laser Absorption Spectroscopy in the mid InfraRed spectral range (IR-TDLAS) has been applied to investigate the behaviour of CF, CF{sub 2} and C{sub 2}F{sub 4} species produced in pulsed CF{sub 4}/H{sub 2} capacitively coupled radio frequency plasmas (13.56 MHz CCP). This experimental technique was shown to be suitable for temporally resolved measurements of the absolute number density of the target molecules in the studied fluorocarbon discharges. The temporal resolution of about 20..40 ms typically achieved in the standard data acquisition mode (''stream mode'') was sufficient for the real-time measurements of CF{sub 2} and C{sub 2}F{sub 4}, but not of CF whose kinetics was observed to be much faster. Therefore, a more sophisticated approach (''burst mode'') providing a temporal resolution of 0.94 ms was established and successfully applied to CF density measurements. In order to enable the TDLAS measurements of the target species, preliminary investigations on their spectroscopic data had been carried out. In particular, pure C{sub 2}F{sub 4} has been produced in laboratory by means of vacuum thermal decomposition (pyrolysis) of polytetrafluoroethylene and used as a reference gas. Therefore, an absorption structure consisting of several overlapping C{sub 2}F{sub 4} lines around 1337.11 cm{sup -1} was selected and carefully calibrated, which provided the first absolute measurements of the species by means of the applied experimental technique. The absolute number density traces measured for CF, CF{sub 2} and C{sub 2}F{sub 4} in the studied pulsed plasmas were then analysed, in which two differential balance equations were proposed for each of the species to describe their behaviour during both ''plasma on'' and ''plasma off'' phases. Analytical solutions of the balance equations were used to fit the experimental data and hence to deduce important information on the kinetics of the studied molecules. In particular, during the ''plasma off'' phase

A Novel Apoptosis Correlated Molecule: Expression and Characterization of Protein Latcripin-1 from Lentinula edodes C>91–3

Directory of Open Access Journals (Sweden)

Min Huang

2012-05-01

Full Text Available An apoptosis correlated molecule—protein Latcripin-1 of Lentinula edodes C>91_-3—was expressed and characterized in Pichia pastoris GS115. The total RNA was obtained from Lentinula edodes C>91–3. According to the transcriptome, the full-length gene of Latcripin-1 was isolated with 3'-Full Rapid Amplification of cDNA Ends (RACE and 5'-Full RACE methods. The full-length gene was inserted into the secretory expression vector pPIC9K. The protein Latcripin-1 was expressed in Pichia pastoris GS115 and analyzed by Sodium Dodecylsulfonate Polyacrylate Gel Electrophoresis (SDS-PAGE and Western blot. The Western blot showed that the protein was expressed successfully. The biological function of protein Latcripin-1 on A549 cells was studied with flow cytometry and the 3-(4,5-Dimethylthiazol-2-yl-2,5-Diphenyl-tetrazolium Bromide (MTT method. The toxic effect of protein Latcripin-1 was detected with the MTT method by co-culturing the characterized protein with chick embryo fibroblasts. The MTT assay results showed that there was a great difference between protein Latcripin-1 groups and the control group (p < 0.05. There was no toxic effect of the characterized protein on chick embryo fibroblasts. The flow cytometry showed that there was a significant difference between the protein groups of interest and the control group according to apoptosis function (p < 0.05. At the same time, cell ultrastructure observed by transmission electron microscopy supported the results of flow cytometry. The work demonstrates that protein Latcripin-1 can induce apoptosis of human lung cancer cells A549 and brings new insights into and advantages to finding anti-tumor proteins.

Simulation of the channelling of ions from MeV C{sub 60} in crystalline solids

Energy Technology Data Exchange (ETDEWEB)

Fetterman, A [Basic and Applied Physics, California Institute of Technology, Pasadena, CA (United States); Sinclair, L [Basic and Applied Physics, California Institute of Technology, Pasadena, CA (United States); Tanushev, N [Basic and Applied Physics, California Institute of Technology, Pasadena, CA (United States); Tombrello, T [Basic and Applied Physics, California Institute of Technology, Pasadena, CA (United States); Nardi, E [Department of Particle Physics, Weizmann Institute of Science Rehovot, 76100 (Israel)

2007-06-14

Simulations were performed describing the motion and breakup of energetic C{sub 60} ions interacting with crystalline targets. A hybrid algorithm was used that employs a binary collision model for the scattering of the carbon ions by the atoms of the solid, and molecular dynamics for the Coulomb interactions of the 60 carbon ions with one another. For the case of yttrium iron garnet (YIG), directions such as [1 1 0], [1 0 0], [0 1 0] and [0 0 1] demonstrate channelling for a large fraction of the C ions. For directions such as [1 1 1], [2 1 1] and [7 5 3] the trajectories show no more channelling than for random directions. The effects of tilt, shielding and wake-field interactions were investigated for YIG and {alpha}-quartz.

Study of the fragmentation of astrophysical interest molecules (C{sub n}H{sub m}) induced by high velocity collision; Etude de la fragmentation de molecules d'interet astrophysique de type C{sub n}H{sub m} par collision atomique de haute vitesse

Energy Technology Data Exchange (ETDEWEB)

Tuna, Th

2008-07-15

This work shows the study of atom-molecule collision processes in the high velocity domain (v=4,5 a.u). The molecules concerned by this work are small unsaturated hydrocarbons C{sub 1-4}H and C{sub 3}H{sub 2}. Molecules are accelerated with the Tandem accelerator in Orsay and their fragmentation is analyzed by the 4{pi}, 100% efficient detector, AGAT. Thanks to a shape analysis of the current signal from the silicon detectors in association with the well known grid method, we are able to measure all the fragmentation channels of the incident molecule. These dissociation measurements have been introduced in the modelization of two objects of the interstellar medium in which a lot of hydrocarbon molecules have been observed (TMC1, horse-head nebula). We have extended our branching ratios obtained by high velocity collision to other electronic processes included in the chemical database like photodissociation and dissociative recombination. This procedure is feasible under an assumption of the statistical point of view of the molecular fragmentation. The deviations following our modification are very small in the modelization of TMC1 but significant in the photodissociation region. The first part is dedicated to the description of the experimental setting that has enabled us to study the fragmentation of C{sub n}H{sub m} molecules: the Orsay's Tandem accelerator and the Agat detector. The second part deals with negative ion sources and particularly with the Sahat source that is based on electronic impact and has shown good features for the production of anions and correct stability for its use with accelerators. The third part is dedicated to the experimental results in terms of cross-sections, number of fragments and branching ratios, associated to the various collisional processes. The last part presents an application of our measurement of fragmentation data to astro-chemistry. In this field, the simulation codes of the inter-stellar medium require databases

Incorporation in Langmuir-Blodgett films of an amphiphilic derivative of fullerene C{sub 60} and oligo-para-phenylenevinylene

Energy Technology Data Exchange (ETDEWEB)

Alvarez-Venicio, V. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (UNAM), Circuito Exterior, CU, C.P. 04510, D.F. (Mexico); Gutierrez-Nava, M. [CIATEQ, A.C., Centro de Tecnologia Avanzada, Circuito de la Industria Poniente Lote: 11, Mza. 3, No. 11, Colonia Parque Industrial Ex Hacienda Dona Rosa, Lerma C.P. 52004, Estado de Mexico (Mexico); Amelines-Sarria, O. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (UNAM), Circuito Exterior, CU, C.P. 04510, D.F. (Mexico); Alvarez-Zauco, E. [Facultad de Ciencias, UNAM, Circuito Exterior, C.U., C.P. 04510, D.F. (Mexico); Basiuk, V.A. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (UNAM), Circuito Exterior, CU, C.P. 04510, D.F. (Mexico); Carreon-Castro, M.P., E-mail: pilar@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (UNAM), Circuito Exterior, CU, C.P. 04510, D.F. (Mexico)

2012-12-30

Langmuir (L) and Langmuir-Blodgett (LB) films of fullerene C{sub 60}-oligo-para-phenylenevinylene (OPV) derivative with six C{sub 12}H{sub 25} aliphatic chains were characterized. For the Langmuir films, isotherms of surface pressure versus molecular area, compression/expansion cycles (hysteresis curves) and Brewster angle microscopic images were obtained. We performed molecular mechanics and density functional theory calculations to determine the molecular and electronic structure of our compound at a water-air interface. We found agreement between experimental and theoretical values for the molecular surface area. LB films of up to ten layers were obtained on glass substrates, and were characterized by ultraviolet-visible spectroscopy. We observed that the absorbance at a wavelength of 326 nm grows almost linearly as a function of the number of layers. Films on glass-indium tin oxide were characterized by atomic force microscopy. We also observed a uniform deposition over the whole area of the scanned substrate. We demonstrated that the fullerene C{sub 60}-OPV derivative is able to form both L and LB films preventing fullerene aggregation with its aliphatic chains. We suggest that, due to its electron-acceptor properties, the C{sub 60}-OPV derivative could be used for organic-photovoltaic and organic-electronic applications. - Highlights: Black-Right-Pointing-Pointer We performed isotherm and hysteresis studies of fullerene derivative compound. Black-Right-Pointing-Pointer We found that the theoretical and experimental molecular areas agree. Black-Right-Pointing-Pointer We deposited Langmuir-Blodgett (LB) films on glass-indium tin oxide. Black-Right-Pointing-Pointer LB films were characterized using UV-visible spectroscopy. Black-Right-Pointing-Pointer We observed the morphology of the LB films through atomic force microscopy.

First C/sub 4/-functionalisation of condensed tannins. Phlobatannins as prototype of a new class of C-ring isomerised oligomers. Die eerste C/sub 4/-funksionalisering van gekondenseerde tanniene. Flobatanniene as prototipe van 'n nuwe klas van C-ring geisomeriseerde oligomere

Energy Technology Data Exchange (ETDEWEB)

Steenkamp, J A

1986-06-01

This thesis comprises besides the characterisation of new oligomeric flavenoids from the core wood of the indigeneous Colophosphermum mopane, an investigation into the C/sub 4/-functionalisation of flavan-3-ol analogues. The first peltogynoid biflavenoid and prototypes of a new series C-ring isomerised condensed tannins, namely the phlobatannins, were isolated. Besides /sup 1/H- nmr-parameters for structure analysis, the natural phlobatannins were characterised and the unique ring isomerisation was investigated.

Electronic structures and magnetism for carbon doped CdSe: Modified Becke–Johnson density functional calculations

Energy Technology Data Exchange (ETDEWEB)

Fan, S.W., E-mail: fansw1129@126.com; Song, T.; Huang, X.N.; Yang, L.; Ding, L.J.; Pan, L.Q.

2016-09-15

Utilizing the full potential linearized augment plane wave method, the electronic structures and magnetism for carbon doped CdSe are investigated. Calculations show carbon substituting selenium could induce CdSe to be a diluted magnetic semiconductor. Single carbon dopant could induce 2.00 μ{sub B} magnetic moment. Electronic structures show the long-range ferromagnetic coupling mainly originates from the p–d exchange-like p–p coupling interaction. Positive chemical pair interactions indicate carbon dopants would form homogeneous distribution in CdSe host. The formation energy implies the non-equilibrium fabricated technology is necessary during the samples fabricated. - Highlights: • The C{sub Se} defects could induce the CdSe to be typical diluted magnetic semiconductor. • Electronic structures show ferromagnetism come from p-d exchange-like p-p coupling. • Chemical pair interactions indicate C{sub Se} prefer homogenous distribution in CdSe host.

Acquisition of a Multi-Domain Advanced Real-Time Simulator to Support DoD-focused Interdisciplinary Research at CSUB

Science.gov (United States)

2017-10-17

SECURITY CLASSIFICATION OF: 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 13. SUPPLEMENTARY NOTES 12. DISTRIBUTION AVAILIBILITY STATEMENT 6...0704-0188 3. DATES COVERED (From - To) - Approved for public release; distribution is unlimited. UU UU UU UU 17-10-2017 25-Jul-2016 24-Jul-2017 Final...Report: Acquisition of a Multi-Domain Advanced Real- Time Simulator to Support DoD-focused Interdisciplinary Research at CSUB The views, opinions and

Characterisation of human hair surfaces by means of static ToF-SIMS: A comparison between Ga{sup +} and C{sub 60} {sup +} primary ions

Energy Technology Data Exchange (ETDEWEB)

Poleunis, Claude [Universite catholique de Louvain (UCL), Unite de Physico-Chimie et de Physique des Materiaux (PCPM), Croix du Sud 1, B-1348 Louvain-la-Neuve (Belgium)]. E-mail: poleunis@pcpm.ucl.ac.be; Everaert, Emmanuel P. [Unilever R and D Port Sunlight, Quarry Road East, Bebington Wirral CH63 3JW (United Kingdom); Delcorte, Arnaud [Universite catholique de Louvain (UCL), Unite de Physico-Chimie et de Physique des Materiaux (PCPM), Croix du Sud 1, B-1348 Louvain-la-Neuve (Belgium); Bertrand, Patrick [Universite catholique de Louvain (UCL), Unite de Physico-Chimie et de Physique des Materiaux (PCPM), Croix du Sud 1, B-1348 Louvain-la-Neuve (Belgium)

2006-07-30

This study deals with the secondary ion yield improvement induced by using C{sub 60} {sup +} primary ions instead of Ga{sup +} ones to characterize human hair surfaces by ToF-SIMS. For that purpose, a bunch of hair fibres has been analysed with both ion sources. A high improvement is observed for the detection of amino acids with C{sub 60} {sup +} primary ions as compared to Ga{sup +} ions. As an example, a yield enhancement factor greater than 3000 is found for the CNO{sup -} peak. A similar gain is observed for the positive secondary ions characteristic of the amino acids. Most of the atomic ions, such as Ca{sup +}, O{sup -} and S{sup -}, constitute minor peaks with C{sub 60} {sup +} ions while they often dominate the spectrum in the case of Ga{sup +} ions. However, with the C{sub 60} {sup +} source, a series of inorganic combination peaks with the elements Ca, S and O are observed in the positive spectra (i.e. HCaSO{sub 4} {sup +}), while they are marginal with the Ga{sup +} source. For the mass range beyond 100 m/z and in both polarities, the hair fingerprints are similar with both sources. In average, for a comparable number of primary ions per spectrum, the C{sub 60} {sup +} ion source gives intensities between two and three orders of magnitude higher than the Ga{sup +} one.

A Small Fullerene (C{sub 24}) may be the Carrier of the 11.2 μ m Unidentified Infrared Band

Energy Technology Data Exchange (ETDEWEB)

Bernstein, L. S.; Shroll, R. M. [Spectral Sciences, Inc., 4 Fourth Ave., Burlington, MA 01803 (United States); Lynch, D. K. [Thule Scientific, P.O. Box 953, Topanga, CA 90290 (United States); Clark, F. O., E-mail: larry@spectral.com, E-mail: rshroll@spectral.com, E-mail: dave@caltech.edu, E-mail: frank.clark@gmail.com [Wopeco Research, 125 South Great Road, Lincoln, MA 01773 (United States)

2017-02-20

We analyze the spectrum of the 11.2 μ m unidentified infrared band (UIR) from NGC 7027 and identify a small fullerene (C{sub 24}) as a plausible carrier. The blurring effects of lifetime and vibrational anharmonicity broadening obscure the narrower, intrinsic spectral profiles of the UIR band carriers. We use a spectral deconvolution algorithm to remove the blurring, in order to retrieve the intrinsic profile of the UIR band. The shape of the intrinsic profile—a sharp blue peak and an extended red tail—suggests that the UIR band originates from a molecular vibration–rotation band with a blue band head. The fractional area of the band-head feature indicates a spheroidal molecule, implying a nonpolar molecule and precluding rotational emission. Its rotational temperature should be well approximated by that measured for nonpolar molecular hydrogen, ∼825 K for NGC 7027. Using this temperature, and the inferred spherical symmetry, we perform a spectral fit to the intrinsic profile, which results in a rotational constant implying C{sub 24} as the carrier. We show that the spectroscopic parameters derived for NGC 7027 are consistent with the 11.2 μ m UIR bands observed for other objects. We present density functional theory (DFT) calculations for the frequencies and infrared intensities of C{sub 24}. The DFT results are used to predict a spectral energy distribution (SED) originating from absorption of a 5 eV photon, and characterized by an effective vibrational temperature of 930 K. The C{sub 24} SED is consistent with the entire UIR spectrum and is the dominant contributor to the 11.2 and 12.7 μ m bands.

Impact of water vapour and carbon dioxide on surface composition of C{sub 3}A polymorphs studied by X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Dubina, E.; Plank, J. [Technische Universität München, Lehrstuhl für Bauchemie, Lichtenbergstr. 4, 85747 Garching bei München (Germany); Black, L., E-mail: l.black@leeds.ac.uk [Institute for Resilient Infrastructure, School of Civil Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom)

2015-07-15

The surface specific analytical method, X-ray photoelectron spectroscopy (XPS), has been used to study the effects of water vapour and CO{sub 2} on the cubic and orthorhombic polymorphs of C{sub 3}A. Significant differences between the two polymorphs were observed in the XPS spectra. Upon exposure to water vapour, both polymorphs produced C{sub 4}AH{sub 13} on their surfaces. Additionally, the sodium-doped o-C{sub 3}A developed NaOH and traces of C{sub 3}AH{sub 6} on its surface. Subsequent carbonation yielded mono carboaluminate on both polymorphs. Large amounts of Na{sub 2}CO{sub 3} also formed on the surface of o-C{sub 3}A as a result of carbonation of NaOH. Furthermore, the extent of carbonation was much more pronounced for o-C{sub 3}A{sub o} than for c-C{sub 3}A.

Parallel detection, quantification, and depth profiling of peptides with dynamic-secondary ion mass spectrometry (D-SIMS) ionized by C{sub 60}{sup +}-Ar{sup +} co-sputtering

Energy Technology Data Exchange (ETDEWEB)

Chang, Chi-Jen [Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China); Chang, Hsun-Yun; You, Yun-Wen; Liao, Hua-Yang [Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan (China); Kuo, Yu-Ting; Kao, Wei-Lun; Yen, Guo-Ji; Tsai, Meng-Hung [Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China); Shyue, Jing-Jong, E-mail: shyue@gate.sinica.edu.tw [Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan (China)

2012-03-09

Highlights: Black-Right-Pointing-Pointer Multiple peptides are detected and quantified at the same time without labeling. Black-Right-Pointing-Pointer C{sub 60}{sup +} ion is responsible for generating molecular-specific ions at high mass. Black-Right-Pointing-Pointer The co-sputtering yielded more steady depth profile and more well defined interface. Black-Right-Pointing-Pointer The fluence of auxiliary Ar{sup +} does not affect the quantification curve. Black-Right-Pointing-Pointer The damage from Ar{sup +} is masked by high sputtering yield of C{sub 60}{sup +}. - Abstract: Time-of-flight secondary ion mass spectrometry (ToF-SIMS) using pulsed C{sub 60}{sup +} primary ions is a promising technique for analyzing biological specimens with high surface sensitivities. With molecular secondary ions of high masses, multiple molecules can be identified simultaneously without prior separation or isotope labeling. Previous reports using the C{sub 60}{sup +} primary ion have been based on static-SIMS, which makes depth profiling complicated. Therefore, a dynamic-SIMS technique is reported here. Mixed peptides in the cryoprotectant trehalose were used as a model for evaluating the parameters that lead to the parallel detection and quantification of biomaterials. Trehalose was mixed separately with different concentrations of peptides. The peptide secondary ion intensities (normalized with respect to those of trehalose) were directly proportional to their concentration in the matrix (0.01-2.5 mol%). Quantification curves for each peptide were generated by plotting the percentage of peptides in trehalose versus the normalized SIMS intensities. Using these curves, the parallel detection, identification, and quantification of multiple peptides was achieved. Low energy Ar{sup +} was used to co-sputter and ionize the peptide-doped trehalose sample to suppress the carbon deposition associated with C{sub 60}{sup +} bombardment, which suppressed the ion intensities during the depth

Fullerenol C{sub 60}(OH){sub 24} nanoparticles decrease relaxing effects of dimethyl sulfoxide on rat uterus spontaneous contraction

Energy Technology Data Exchange (ETDEWEB)

Slavic, Marija, E-mail: marija17@ibiss.bg.ac.rs [University of Belgrade, Department for Physiology, Institute for Biological Research ' Sinisa Stankovic' (IBISS) (Serbia); Djordjevic, Aleksandar [University of Novi Sad, Department of Chemistry, Biochemistry and the Environment, Faculty of Sciences (Serbia); Radojicic, Ratko [University of Belgrade, Faculty of Biology (Serbia); Milovanovic, Slobodan [University of East Sarajevo, Department of Pharmacology, Faculty of Medicine at Foca (Bosnia and Herzegowina); Orescanin-Dusic, Zorana [University of Belgrade, Department for Physiology, Institute for Biological Research ' Sinisa Stankovic' (IBISS) (Serbia); Rakocevic, Zlatko [University of Belgrade, Institute for Nuclear Sciences ' Vinca' (Serbia); Spasic, Mihajlo B.; Blagojevic, Dusko [University of Belgrade, Department for Physiology, Institute for Biological Research ' Sinisa Stankovic' (IBISS) (Serbia)

2013-05-15

Dimethyl sulfoxide (DMSO) is a widely used solvent and cryoprotectant that can cause impaired blood flow, reduction in intracranial pressure, tissue edema, inflammatory reactions, inhibition of vascular smooth muscle cell migration and proliferation, processes which can lead to atherosclerosis of the coronary, peripheral and cerebral circulation. Although the adverse effects are rare when DMSO is administered in clinically established concentrations, there is no safe antagonist for an overdose. In this work, we treated isolated spontaneous and calcium-induced contractile active rat uteri (Wistar, virgo intacta), with DMSO and fullerenol C{sub 60}(OH){sub 24} nanoparticle (FNP) in DMSO. FNP is a water-soluble derivative of fullerene C{sub 60}. Its size is a 1.1 nm in diameter and is a very promising candidate for a drug carrier in nanomedicine. FNP also displays free radical scavenging activity. DMSO decreased both spontaneous and calcium-induced contractions. In contrast, FNP only decreased spontaneous contraction. FNP decreased copper-zinc superoxide dismutase activity and prevented the DMSO-induced increase in glutathione reductase activity. Atomic force microscopy detected that FNP aggregated with calcium ions. Our results indicate that FNP has properties that make it a good candidate to be a modulator of DMSO activity which could minimize side effects of the latter.

Synthesis of dimethyl-1,1 guanylguanidine-{sup 14}C-2,4 (dimethyl-1-1 biguanide) hydrochloride; Synthese du chlorhydrate de dimethyl-1,1 guanylguanidine {sup 14}C-2,4 (dimethyl-1-1 biguanide)

Energy Technology Data Exchange (ETDEWEB)

Herbert, M; Pichat, L [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1961-07-01

A description of the synthesis of dimethyl-1,1 guanylguanidine-{sup 14}C-2,4 hydrochloride passing through the {sup 14}C{sub 2} dicyandiamide. The overall yield with respect to Ba{sup 14}CO{sub 3} is 38 per cent. (author) [French] Description de la synthese du chlorhydrate de dimethyl-1,1 guanylguanidine {sup 14}C-2,4 par l'intermediaire de la dicyandiamide {sup 14}C{sub 2}. Le rendement global par rapport a {sup 14}CO{sub 3}Ba est de 38 pour cent. (auteur)

X-ray crystal and molecular structure of (eta/sup 5/C/sub 5/H/sub 5/)UCl/sub 3/. 2PPh/sub 3/O thf: trichloro (eta/sup 5/cyclopentadienyl)bis(triphenylphosphine oxide) uranium(IV). thf

Energy Technology Data Exchange (ETDEWEB)

Bombieri, G; De Paoli, G [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi; Del Pra, A; Bagnall, K W

1978-01-01

Following reports of the preparation of (eta/sup 5/C/sub 5/H/sub 5/)UCl/sub 3/.xL (x = 1, L = dimethoxyethane and x = 2, L = tetrahydrofuran (thf), a series of analogous oxygen-donor complexes were isolated. This paper describes the crystal and molecular structure of one of them, ((eta/sup 5/C/sub 5/H/sub 5/)UCl/sub 3/.2PPh/sub 3/O)thf.

A direct investigation of photocharge transfer across monomolecular layer between C{sub 60} and CdS quantum dots by photoassisted conductive atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Jiang, Xiaohong; Liu, He; Zhang, Xingtang; Cheng, Gang; Wang, Shujie; Du, Zuliang, E-mail: zld@henu.edu.cn [Key Laboratory for Special Functional Materials, Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng, 475004, PR. China (China)

2016-04-15

The composite assembly of C{sub 60} and CdS Quantum Dots (QDs) on ITO substrate was prepared by Langmuir-Blodgett (LB) technique using arachic acid (AA), stearic acid (SA) and octadecanyl amine (OA) as additives. Photoassisted conductive atomic force microscopy was used to make point contact current-voltage (I-V) measurements on both the CdS QDs and the composite assembly of C{sub 60}/CdS. The result make it clear that the CdS, C{sub 60}/CdS assemblies deposited on ITO substrate showed linear characteristics and the current increased largely under illumination comparing with that in the dark. The coherent, nonresonant tunneling mechanism was used to explain the current occurrence. It is considered that the photoinduced carriers CdS QDs tunneled through alkyl chains increased the current rapidly.

Molecular depth profiling of trehalose using a C{sub 60} cluster ion beam

Energy Technology Data Exchange (ETDEWEB)

Wucher, Andreas [Department of Physics, University of Duisburg-Essen, D-47048 Duisburg (Germany)], E-mail: andreas.wucher@uni-due.de; Cheng Juan; Winograd, Nicholas [Department of Chemistry, Pennsylvania State University, University Park, PA 16802 (United States)

2008-12-15

Molecular depth profiling of organic overlayers was performed using a mass selected fullerene ion beam in conjunction with time-of-flight (TOF-SIMS) mass spectrometry. The characteristics of depth profiles acquired on a 300-nm trehalose film on Si were studied as a function of the impact kinetic energy and charge state of the C{sub 60} projectile ions. We find that the achieved depth resolution depends only weakly upon energy.

HTLV-1 Rex: the courier of viral messages, making use of the host vehicle

Directory of Open Access Journals (Sweden)

Kazumi eNakano

2012-09-01

Full Text Available The human T-cell leukemia virus type 1 (HTLV-1 is a retrovirus causing an aggressive T-cell malignancy, adult T-cell leukemia (ATL. Although HTLV-1 has a compact RNA genome, it has evolved elaborate mechanisms to maximize its coding potential. The structural proteins Gag, Pro, and Pol are encoded in the unspliced form of viral mRNA, whereas the Env protein is encoded in singly spliced viral mRNA. Regulatory and accessory proteins, such as Tax, Rex, p30II, p12, and p13, are translated only from fully spliced mRNA. For effective viral replication, translation from all forms of HTLV-1 transcripts has to be achieved in concert, although unspliced mRNA are extremely unstable in mammalian cells. It has been well recognized that HTLV-1 Rex enhances the stability of unspliced and singly spliced HTLV-1 mRNA by promoting nuclear export and thereby, removing them from the splicing site. Rex specifically binds to the highly structured Rex responsive element (RxRE located at the 3′ end of all HTLV-1 mRNA. Rex then binds to the cellular nuclear exporter, CRM1, via its nuclear export signal domain and the Rex-viral transcript complex is selectively exported from the nucleus to the cytoplasm for effective translation of the viral proteins. Yet, the mechanisms by which Rex inhibits the cellular splicing machinery and utilizes the cellular pathways beneficial to viral survival in the host cell have not been fully explored. Furthermore, physiological impacts of Rex against homeostasis of the host cell via interactions with numerous cellular proteins have been largely left uninvestigated. In this review, we focus on the biological importance of HTLV-1 Rex in the HTLV-1 life cycle by following the historical path in the literature concerning this viral post-transcriptional regulator from its discovery to this day. In addition, for future studies, we discuss recently discovered aspects of HTLV-1 Rex as a post-transcriptional regulator and its use in host cellular

/sup 13/C, /sup 17/O, and /sup 33/S NMR spectra of alkyl phenyl sulfones C/sub 6/H/sub 5/SO/sub 2/Alk

Energy Technology Data Exchange (ETDEWEB)

Bzhezovskii, V.M.; Valeev, R.B.; Kalabin, G.A.; Aliev, I.A.

1987-06-20

The /sup 13/C, /sup 17/O, and /sup 33/S NMR spectra of alkyl phenyl sulfones C/sub 6/H/sub 5/SO/sub 2/Alk were obtained. The changes in the screening of the /sup 13/C, /sup 17/O, and /sup 33/S nuclei in these compounds are determined by the effect of the alkyl substituents, which alternates in sign and decreases along the chain of atoms in the order: CH/sub 3/, C/sub 2/H/sub 5/, iso-C/sub 3/H/sub 7/, and tert-C/sub 4/H/sub 9/. In the alkyl phenyl sulfides C/sub 6/H/sub 5/SAlk the additional effect of disruption in the p,..pi.. interaction between the sulfur atom and the benzene ring as a result of conformational changes is superimposed on the screening of the /sup 13/C/sup ortho/ nuclei. For the changes in the screening of the /sup 13/C/sup para/ nuclei in C/sub 6/H/sub 5/SAlk the steric disruption of the p,..pi.. conjugation by the alkyl substituents is determining.

AN UNBIASED 1.3 mm EMISSION LINE SURVEY OF THE PROTOPLANETARY DISK ORBITING LkCa 15

Energy Technology Data Exchange (ETDEWEB)

Punzi, K. M.; Kastner, J. H. [Center for Imaging Science, School of Physics and Astronomy, and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States); Hily-Blant, P.; Forveille, T. [UJF—Grenoble 1/CNRS-INSU, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG) UMR 5274, F-38041, Grenoble (France); Sacco, G. G. [INAF—Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125, Firenze (Italy)

2015-06-01

The outer (>30 AU) regions of the dusty circumstellar disk orbiting the ∼2–5 Myr old, actively accreting solar analog LkCa 15 are known to be chemically rich, and the inner disk may host a young protoplanet within its central cavity. To obtain a complete census of the brightest molecular line emission emanating from the LkCa 15 disk over the 210–270 GHz (1.4–1.1 mm) range, we have conducted an unbiased radio spectroscopic survey with the Institute de Radioastronomie Millimétrique (IRAM) 30 m telescope. The survey demonstrates that in this spectral region, the most readily detectable lines are those of CO and its isotopologues {sup 13}CO and C{sup 18}O, as well as HCO{sup +}, HCN, CN, C{sub 2}H, CS, and H{sub 2}CO. All of these species had been previously detected in the LkCa 15 disk; however, the present survey includes the first complete coverage of the CN (2–1) and C{sub 2}H (3–2) hyperfine complexes. Modeling of these emission complexes indicates that the CN and C{sub 2}H either reside in the coldest regions of the disk or are subthermally excited, and that their abundances are enhanced relative to molecular clouds and young stellar object environments. These results highlight the value of unbiased single-dish line surveys in guiding future high-resolution interferometric imaging of disks.

Electronic structure evolution in doping of fullerene (C{sub 60}) by ultra-thin layer molybdenum trioxide

Energy Technology Data Exchange (ETDEWEB)

Wang, Chenggong; Wang, Congcong; Kauppi, John [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Liu, Xiaoliang [Institute for Super-microstructure and Ultrafast Process in Advanced Materials (ISUPAM), Central South University, Changsha, Hunan 410083 (China); Gao, Yongli, E-mail: ygao@pas.rochester.edu [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Institute for Super-microstructure and Ultrafast Process in Advanced Materials (ISUPAM), Central South University, Changsha, Hunan 410083 (China)

2015-08-28

Ultra-thin layer molybdenum oxide doping of fullerene has been investigated using ultraviolet photoemission spectroscopy (UPS) and X-ray photoemission spectroscopy (XPS). The highest occupied molecular orbital (HOMO) can be observed directly with UPS. It is observed that the Fermi level position in fullerene is modified by ultra-thin-layer molybdenum oxide doping, and the HOMO onset is shifted to less than 1.3 eV below the Fermi level. The XPS results indicate that charge transfer was observed from the C{sub 60} to MoO{sub x} and Mo{sup 6+} oxides is the basis as hole dopants.

Self-interaction corrections applied to Mg-porphyrin, C{sub 60}, and pentacene molecules

Energy Technology Data Exchange (ETDEWEB)

Pederson, Mark R. [Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Baruah, Tunna; Basurto, Luis [Department of Physics, The University of Texas at El Paso, El Paso, Texas 79968 (United States); Kao, Der-you [Department of Mechanical and Aerospace Engineering, George Washington University, Washington, DC 20052 (United States)

2016-04-28

We have applied a recently developed method to incorporate the self-interaction correction through Fermi orbitals to Mg-porphyrin, C{sub 60}, and pentacene molecules. The Fermi-Löwdin orbitals are localized and unitarily invariant to the Kohn-Sham orbitals from which they are constructed. The self-interaction-corrected energy is obtained variationally leading to an optimum set of Fermi-Löwdin orbitals (orthonormalized Fermi orbitals) that gives the minimum energy. A Fermi orbital, by definition, is dependent on a certain point which is referred to as the descriptor position. The degree to which the initial choice of descriptor positions influences the variational approach to the minimum and the complexity of the energy landscape as a function of Fermi-orbital descriptors is examined in detail for Mg-porphyrin. The applications presented here also demonstrate that the method can be applied to larger molecular systems containing a few hundred electrons. The atomization energy of the C{sub 60} molecule within the Fermi-Löwdin-orbital self-interaction-correction approach is significantly improved compared to local density approximation in the Perdew-Wang 92 functional and generalized gradient approximation of Perdew-Burke-Ernzerhof functionals. The eigenvalues of the highest occupied molecular orbitals show qualitative improvement.

A host MicroRNA brokers truce with HSV-1.

Science.gov (United States)

Pare, Justin M; Sullivan, Christopher S

2014-04-09

Establishing lifelong infection and periodically shedding infectious progeny is a successful strategy employed by several persistent pathogens. In this issue of Cell Host & Microbe, Pan et al. (2014) demonstrate that a cell-type-specific host microRNA can restrict gene expression and pathogenicity of herpes simplex virus 1, thereby promoting long-term infection. Copyright © 2014 Elsevier Inc. All rights reserved.

Synthesis, vibrational and optical properties of a new three-layered organic-inorganic perovskite (C{sub 4}H{sub 9}NH{sub 3}){sub 4}Pb{sub 3}I{sub 4}Br{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Dammak, T., E-mail: thameurlpa@yahoo.f [Laboratoire de Physique appliquee (LPA), Faculte des Sciences de Sfax, 3018, BP 802 (Tunisia); Elleuch, S. [Laboratoire de Physique appliquee (LPA), Faculte des Sciences de Sfax, 3018, BP 802 (Tunisia); Bougzhala, H. [Laboratoire de cristallochimie et des materiaux, Faculte des Sciences de Tunis (Tunisia); Mlayah, A. [Centre d' Elaboration de Materiaux et d' Etudes Structurales, CNRS-Universite Paul Sabatier, 29 rue Jeanne Marvig, 31055 Toulouse, Cedex 4 (France); Chtourou, R. [Centre de Recherche et des Technologies de l' Energie CRTEn BP. 95, Hammam-Lif 2050, Laboratoire de Photovoltaique et de Semiconducteur (Tunisia); Abid, Y. [Laboratoire de Physique appliquee (LPA), Faculte des Sciences de Sfax, 3018, BP 802 (Tunisia)

2009-09-15

An organic-inorganic hybrid perovskite (C{sub 4}H{sub 9}NH{sub 3}){sub 4}Pb{sub 3}I{sub 4}Br{sub 6} was synthesized and studied by X-ray diffraction, Raman and infrared spectroscopies, optical transmission and photoluminescence. The title compound, abbreviated (C{sub 4}){sub 4}Pb{sub 3}I{sub 4}Br{sub 6}, crystallises in a periodic two-dimensional multilayer structure with P2{sub 1}/a space group. The structure is built up from alternating inorganic and organic layers. Each inorganic layer consists of three sheets of PbX{sub 6} (X=I, Br) octahedra. Raman and infrared spectra of the title compound were recorded in the 100-3500 and 400-4000 cm{sup -1} frequency ranges, respectively. An assignment of the observed vibration modes is reported. Optical transmission measurements, performed on thin films of (C{sub 4}){sub 4}Pb{sub 3}I{sub 4}Br{sub 6}, revealed two absorption bands at 474 and 508 nm. Photoluminescence measurements have shown a green emission peak at 519 nm.

Broad-Host-Range IncP-1 plasmids and their resistance potential

Directory of Open Access Journals (Sweden)

Magdalena ePopowska

2013-03-01

Full Text Available The plasmids of the incompatibility group IncP-1, also called IncP, as extrachromosomal genetic elements can transfer and replicate virtually in all Gram-negative bacteria. They are composed of backbone genes that encode a variety of essential functions and accessory genes that have implications for human health and environmental bioremediation. Broad-host-range IncP plasmids are known to spread genes between distinct phylogenetic groups of bacteria. These genes often code for resistances to a broad spectrum of antibiotics, heavy metals and quaternary ammonium compounds used as disinfectants. The backbone of these plasmids carries modules that enable them to effectively replicate, move to a new host via conjugative transfer and to be stably maintained in bacterial cells. The adaptive, resistance and virulence genes are mainly located on mobile genetic elements integrated between the functional plasmid backbone modules. Environmental studies have demonstrated the wide distribution of IncP-like replicons in manure, soils and wastewater treatment plants. They also are present in strains of pathogenic or opportunistic bacteria, which can be a cause for concern, because they may encode multiresistance. Their broad distribution suggests that IncP plasmids play a crucial role in bacterial adaptation by utilizing horizontal gene transfer. This review summarizes the variety of genetic information and physiological functions carried by IncP plasmids, which can contribute to the spread of antibiotic and heavy metal resistance while also mediating the process of bioremediation of pollutants. Due to the location of the resistance genes on plasmids with a broad host range and the presence of transposons carrying these genes it seems that the spread of these genes would be possible and quite hazardous in infection control. Future studies are required to determine the level of risk of the spread of resistance genes located on these plasmids.

High voltage research (breakdown strengths of gaseous and liquid insulators). Semiannual report, April 1--September 30, 1977

Energy Technology Data Exchange (ETDEWEB)

Christophorou, L. G.; James, D. R.; Pai, R. Y.; Mathis, R. A.; Pace, M. O.; Bouldin, D. W.; Christodoulides, A. A.; Chan, C. C.

1977-11-01

Direct current breakdown strength measurements on a large number of multicomponent gas mixtures at low (approximately less than 1 atm) and high (approximately less than 5 atm) pressures led to the discovery of many gas mixtures of electron-attaching gases and strongly electron-attaching gases with N/sub 2/ and C/sub 3/F/sub 8/ which are superior to SF/sub 6/. Of special significance are mixtures containing C/sub 4/F/sub 6/ (perfluoro-2-butyne). The breakdown strength of one such mixture (20 percent C/sub 4/F/sub 6/ to 80 percent SF/sub 6/) is approximately 30 percent higher than pure SF/sub 6/ under identical conditions, both at low (approximately 0.7 atm) and high (4.6 atm) pressures. Perfluorocyclohexene (C/sub 6/F/sub 10/) and C/sub 5/F/sub 8/ (perfluorocyclopentene) were found at low pressure (approximately 0.2 atm) to be, respectively, approximately 2.1 and 2.2 times better than SF/sub 6/ under comparable conditions; they both have a potential as additives in gas mixtures. The effect of the inelastic electron scattering properties of a gas via negative ion resonances in the low-energy range (1 to approximately 4 eV) on the breakdown strength has been demonstrated for H/sub 2/, N/sub 2/, and CO and binary mixtures of these with SF/sub 6/ and C/sub 4/F/sub 6/ (perfluoro-2-butyne). The construction of a new high pressure (to approximately 11 atm), variable temperature (-50/sup 0/C to + 150/sup 0/C) apparatus has been completed and a practical test facility utilizing cylindrical electrode geometries has been put into operation; the first results on the latter apparatus were on SF/sub 6/-N/sub 2/ and c-C/sub 4/F/sub 8/--N/sub 2/ mixtures. Studies of environmental effects of dielectric gases via their electron-impact-induced decompositions and analysis of their breakdown products have begun using mass spectrometry and gas chromatography; C/sub 4/F/sub 6/ (perfluoro-2-butyne) seems to be resistant to electron-impact-induced decomposition indicating long

On the Utility of Spinel Oxide Hosts for Magnesium-Ion Batteries.

Science.gov (United States)

Knight, James C; Therese, Soosairaj; Manthiram, Arumugam

2015-10-21

There is immense interest to develop Mg-ion batteries, but finding suitable cathode materials has been a challenge. The spinel structure has many advantages for ion insertion and has been successfully used in Li-ion batteries. We present here findings on the attempts to extract Mg from MgMn2O4-based spinels with acid (H2SO4) and with NO2BF4. The acid treatment was able to fully remove all Mg from MgMn2O4 by following a mechanism involving the disproportionation of Mn(3+), and the extraction rate decreased with increasing cation disorder. Samples with additional Mg(2+) ions in the octahedral sites (e.g., Mg1.1Mn1.9O4 and Mg1.5Mn1.5O4) also exhibit complete or near complete demagnesiation due to an additional mechanism involving ion exchange of Mg(2+) by H(+), but no Mg could be extracted from MgMnAlO4 due to the disruption of Mn-Mn interaction/contact across shared octahedral edges. In contrast, no Mg could be extracted with the oxidizing agent NO2BF4 from MgMn2O4 or Mg1.5Mn1.5O4 as the electrostatic repulsion between the divalent Mg(2+) ions prevents Mg(2+) diffusion through the 16c octahedral sites, unlike Li(+) diffusion, suggesting that spinels may not serve as potential hosts for Mg-ion batteries. The ability to extract Mg with acid in contrast to that with NO2BF4 is attributed to Mn dissolution from the lattice and the consequent reduction in electrostatic repulsion. The findings could provide insights toward the design of Mg hosts for Mg-ion batteries.

Changes in soil N fractions and utilization of recently immobilized fertilizer N by wheat as influenced by application of some organic chemicals in rice-wheat sequence

International Nuclear Information System (INIS)

Patel, K.P.; Jain, J.M.

1993-01-01

Effect of two organic chemicals viz., 2,4-dinitrophenyl hydrazone (C 1 ) and naphthyl ethylene diamine (C 2 ) was studied by their application alone and together (Csub(1+2) at the rate of 10 ppm by growing wheat on a loamy soil (Typic ustochrept) containing recently immobilized fertilizes N of 15 N - urea applied at 60, 120 and 180 ppm N to preceding rice under greenhouse conditions of a rice-wheat sequence. The application of C 1 and C 2 alone; and their combined application (Csub(1+2) produced 12, 15 and 18 per cent higher wheat grain yield over no-chemical application i.e. Co (3.50 g/pot). The chemicals also showed their beneficial effect on utilization of recently immobilized fertilizer N, as was evidenced by significantly higher 15 N recovery values in wheat with C 1 , C 2 and Csub(1+2)(2.84, 3.63 and 3.54 per cent, respectively) than that of Co (2.29 per cent). The soil N fractions were affected by chemical application during wheat as total hydrolyzable N, hydrolyzable unidentified N and hydrolyzable ammonia N registered a decrease in the presence of chemicals whereas the contents of acid insoluble N and amino acid N fractions were found to be increased compared to respective contents after rice, and inorganic N showed a continuous decrease irrespective of the treatments. Amino acid N and hydrolyzable ammonia N were found to be dominant fractions whereas amino sugar N contributed minimum towards total hydrolyzable N at all stages of rice-wheat sequence. (author). 11 refs., 4 tabs

Measurement of the spin-spin correlation parameter C/sub LL/(THETA) in proton-proton scattering

International Nuclear Information System (INIS)

Stuart, S.J.

1982-08-01

The experimental procedures and methods of data analysis used to measure the spin-spin correlation parameter C/sub LL/(THETA) in proton-proton scattering at thirteen different energies in the range 300 to 800 MeV are presented. The results compare favorably with previous data. Good agreement is found with phase shift predictions at energies below 500 MeV

On the possibility of considering the fullerene shell C{sub 60} as a conducting sphere

Energy Technology Data Exchange (ETDEWEB)

Amusia, M.Ya. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Ioffe Physical-Technical Institute, St. Petersburg 194021 (Russian Federation); Baltenkov, A.S. [Arifov Institute of Electronics, Tashkent 700125 (Uzbekistan)]. E-mail: arkbalt@mail.ru

2006-12-25

The dynamical and static dipole polarizabilities of the C{sub 60} molecule have been calculated on the basis of the experimental data on the cross section of the fullerene photoabsorption. It has been shown that the fullerene shell in the static electric field behaves most likely as a set of separate carbon atoms rather than as a conducting sphere.

Recognition of HIV-1 peptides by host CTL is related to HIV-1 similarity to human proteins.

Directory of Open Access Journals (Sweden)

Morgane Rolland

Full Text Available BACKGROUND: While human immunodeficiency virus type 1 (HIV-1-specific cytotoxic T lymphocytes preferentially target specific regions of the viral proteome, HIV-1 features that contribute to immune recognition are not well understood. One hypothesis is that similarities between HIV and human proteins influence the host immune response, i.e., resemblance between viral and host peptides could preclude reactivity against certain HIV epitopes. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed the extent of similarity between HIV-1 and the human proteome. Proteins from the HIV-1 B consensus sequence from 2001 were dissected into overlapping k-mers, which were then probed against a non-redundant database of the human proteome in order to identify segments of high similarity. We tested the relationship between HIV-1 similarity to host encoded peptides and immune recognition in HIV-infected individuals, and found that HIV immunogenicity could be partially modulated by the sequence similarity to the host proteome. ELISpot responses to peptides spanning the entire viral proteome evaluated in 314 individuals showed a trend indicating an inverse relationship between the similarity to the host proteome and the frequency of recognition. In addition, analysis of responses by a group of 30 HIV-infected individuals against 944 overlapping peptides representing a broad range of individual HIV-1B Nef variants, affirmed that the degree of similarity to the host was significantly lower for peptides with reactive epitopes than for those that were not recognized. CONCLUSIONS/SIGNIFICANCE: Our results suggest that antigenic motifs that are scarcely represented in human proteins might represent more immunogenic CTL targets not selected against in the host. This observation could provide guidance in the design of more effective HIV immunogens, as sequences devoid of host-like features might afford superior immune reactivity.

Theoretical assessment of the electro-optical features of the group III nitrides (B{sub 12}N{sub 12}, Al{sub 12}N{sub 12} and Ga{sub 12}N{sub 12}) and group IV carbides (C{sub 24}, Si{sub 12}C{sub 12} and Ge{sub 12}C{sub 12}) nanoclusters encapsulated with alkali metals (Li, Na and K)

Energy Technology Data Exchange (ETDEWEB)

Tahmasebi, Elham [Chemistry Department, Faculty of Science, Lorestan University, Khorram Abad, Lorestan (Iran, Islamic Republic of); Shakerzadeh, Ehsan, E-mail: e.shakerzadeh@scu.ac.ir [Chemistry Department, Faculty of Science, Shahid Chamran University, Ahvaz (Iran, Islamic Republic of); Biglari, Zeinab [Chemistry Department, Faculty of Science, Lorestan University, Khorram Abad, Lorestan (Iran, Islamic Republic of)

2016-02-15

Graphical abstract: - Highlights: • Encapsulation of Li, Na and K narrow the HOMO–LUMO gaps of the clusters. • The group III nitrides nanoclusters strongly interacted with the alkali metals. • First hyperpolarizabilities remarkably enhance for B{sub 12}N{sub 12} encapsulated with Na/K. - Abstract: Density functional theory (DFT) calculations have been carried out to study the influence of alkali metals (Li, Na and K) encapsulation within the group III nitrides (B{sub 12}N{sub 12}, Al{sub 12}N{sub 12} and Ga{sub 12}N{sub 12}) and the group IV carbides (C{sub 24}, Si{sub 12}C{sub 12}and Ge{sub 12}C{sub 12}) nanoclusters. The encapsulation of Li, Na and K atoms is found to narrow the HOMO–LUMO gaps of the considered clusters. The electronic properties of these clusters, especially the group III nitrides nanoclusters, are strongly sensitive to interaction with the alkali metals. Moreover it is observed that the encapsulation of alkali metals enhances the first hyperpolarizabilities of B{sub 12}N{sub 12} nanocluster. Surprisingly, due to the alkali metals encapsulation within B{sub 12}N{sub 12} nanocluster, the first hyperpolarizability values are remarkably increased to 8505.49 and 122,503.76 a.u. for Na@B{sub 12}N{sub 12} and K@B{sub 12}N{sub 12}, respectively. Also the TD-DFT calculations at both CAM-B3LYP/6-311+G(d) and PBE0/6-311+G(d) levels of theory are also performed to investigate the origin of first hyperpolarizabilities.

New triboluminescence emitters of inorganic lanthanide salts in CH{sub 4} and C{sub 2}H{sub 2} atmosphere

Energy Technology Data Exchange (ETDEWEB)

Tukhbatullin, A.A., E-mail: adiska0501@gmail.ru; Sharipov, G.L.; Bagautdinova, A.R.

2016-05-15

Excited radicals {sup *}CH and {sup *}C{sub 2} have been registered as light-emitting products of the mechanochemical decomposition of hydrocarbon gases (natural gas, CH{sub 4}, and C{sub 2}H{sub 2}) occurring at decomposition of the hydrated cerium and terbium sulfates under atmosphere of these gases, followed by triboluminescence. The inlet of hydrocarbons almost does not affect the intensity of the solid-state components of triboluminescence, viz., the luminescence of the excited ions Ln{sup 3+}. However, these gases completely suppress the luminescence of molecular nitrogen observed in air (a gas component of triboluminescence). The mechanism of decomposition of methane and acetylene by electrical discharges generated by the destruction of the crystals (the main source of gas component triboluminescence) have been discussed.

Bacterial and human cell mutagenicity study of some C[sub 18]H[sub 10] cyclopenta-fused polycyclic aromatic hydrocarbons associated with fossil fuels combustion

Energy Technology Data Exchange (ETDEWEB)

Lafleur, A.L.; Longwell, J.P.; Marr, J.A.; Monchamp, P.A.; Thilly, W.G. (Massachusetts Institute of Technology, Cambridge (United States)); Mulder, P.P.Y.; Boere, B.B.; Cornelisse, J.; Lugtenburg, J. (Univ. of Leiden (Netherlands))

1993-06-01

A number of isomeric C[sub 18]H[sub 10] polycyclic aromatic hydrocarbons (PAHs), thought to be primarily cyclopenta-fused PAHs, are produced during the combustion and pyrolysis of fossil fuels. To determine the importance of their contributions to the total mutagenic activity of combustion and pyrolysis samples in which they are found, we characterized reference quantities of four C[sub 18]H[sub 10] CP-PAHs: benzol [ghi] fluoranthene (BF), cyclopenta [cd] pyrene (CPP), cyclopent [hi] acephenanthrylene (CPAP), and cyclopent [hi] acaenthrylene (CPAA). Synthesis of CPAA and CPAP is described. The availability of reference samples of these isomers also proved to be an essential aid in the identification of the C[sub 18]H[sub 10] species often found in combustion and pyrolysis samples. Chemical analysis of selected combustion and pyrolysis samples showed that CPP was generally the most abundant C[sub 18]H[sub 10] isomer, followed by CPAP and BF. CPAA was detected only in pyrolysis products from pure PAHs. We tested the four C[sub 18]H[sub 10] PAHs for mutagenicity in a forward mutation assay using S. typhimurium. CPP, BF, and CPAA were roughly twice as mutagenic as benzo[a]pyrene (BaP), whereas CPAP was only slightly active. These PAHs were also tested for mutagenic activity in human cells. In this assay, CPP and CPAA were strongly mutagenic but less active than BaP, whereas CPAP and BF were inactive at the dose levels tested. Also, the bacterial and human cell mutagenicity of CPAA and CPAP were compared with the mutagenicity of their monocyclopenta-fused analogs, aceanthrylene and acephenanthrylene. Although the mutagenicities of CPAP and acephenanthrylene are similar, the mutagenic activity of CPAA is an order of magnitude greater than that of aceanthrylene.

Molecular Mechanisms of Host Cytoskeletal Rearrangements by Shigella Invasins

Directory of Open Access Journals (Sweden)

Jun Hyuck Lee

2014-10-01

Full Text Available Pathogen-induced reorganization of the host cell cytoskeleton is a common strategy utilized in host cell invasion by many facultative intracellular bacteria, such as Shigella, Listeria, enteroinvasive E. coli and Salmonella. Shigella is an enteroinvasive intracellular pathogen that preferentially infects human epithelial cells and causes bacillary dysentery. Invasion of Shigella into intestinal epithelial cells requires extensive remodeling of the actin cytoskeleton with the aid of pathogenic effector proteins injected into the host cell by the activity of the type III secretion system. These so-called Shigella invasins, including IpaA, IpaC, IpgB1, IpgB2 and IpgD, modulate the actin-regulatory system in a concerted manner to guarantee efficient entry of the bacteria into host cells.

Occurrence of high molecular weight lipids (C{sub 80+}) in the trilaminar outer cell walls of some freshwater microalgae. A reappraisal of algaenan structure

Energy Technology Data Exchange (ETDEWEB)

Allard, B.; Templier, J. [UMR CNRS, Paris (France). Laboratoire de Chimie Bioorganique et Organique Physique; Rager, M.-N. [UMR CNRS, Paris (France). Service RMN

2002-07-01

The purified cell walls of mother cells (CWM) were isolated from three strains of trilaminar sheath (TLS)- and algaenan-containing freshwater microalgae Chlorella emersonii, Tetraedron minimum and Scenedesmus communis. The chemical structures of CWM and algaenans were investigated by means of tetramethylammonium hydroxide (TMAH) hydrolysis and tetramethylammonium hydroxide thermochemolysis. The compounds released were characterised by {sup 1}H and {sup 13}C-NMR, gel permeation chromatography and desorption chemical ionisation mass spectrometry. The results show that the outer cell walls of the microalgae are constituted, at least in part, of linear (poly)esters containing extremely long chain alcohol and acid moieties (up to C{sub 80}) and that algaenans are mainly composed of extremely long chain (di)carboxylic acids up to C{sub 120}. The present results which are in direct contrast to the previous three-dimensional architecture proposed for algaenans, led us to re-interpret the algaenan structure. (Author)

Low energy electron spectroscopy of C{sub 60} in collisions with fast bare ions: Observation of GDPR peak and its angular distribution

Energy Technology Data Exchange (ETDEWEB)

Kelkar, A H; Misra, D; Chatterjee, S; Kasthurirangan, S; Agnihotri, A; Tribedi, L C, E-mail: lokesh@tifr.res.i [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400005 (India)

2009-11-01

We report the first direct measurement of GDPR peak in heavy ion (4 MeV/u F''9''+) induced secondary electron DDCS (double differential cross section) spectrum of C{sub 60} fullerene. A peak corresponding to GDPR is seen at all angles and the angular distribution, showing a dip at 90''0, is in contrast with ion-atom collisions, indicating plasmon oscillations along beam direction. A comparison has also been done between C{sub 60} and other gaseous targets as well as with state-of-the art theoretical models, based on density functional methods.

Synthesis, crystal structure, thermal analysis and dielectric properties of [(C{sub 4}H{sub 9}){sub 4}N]{sub 3}Bi{sub 2}Cl{sub 9} compound

Energy Technology Data Exchange (ETDEWEB)

Trigui, W., E-mail: walatrigui@yahoo.fr; Oueslati, A.; Chaabane, I.; Hlel, F.

2015-07-15

A new organic–inorganic tri-tetrabutylammonium nonachlorobibismuthate(III) compound was prepared. It was found to crystallize in the monoclinic system (P2{sub 1}/n space group) with the following lattice parameters: a=11.32(2) Å, b=22.30(3) Å, c=28.53(2) Å and β=96.52(0)°. The [Bi{sub 2}Cl{sub 9}]{sup 3−} anions are surrounded by six [(C{sub 4}H{sub 9})N]{sup +} cations, forming an octahedral configuration. These octahedra are sharing corners in order to provide the tri-dimensional network cohesion. The differential scanning calorimetry reveals four order-disorder reversible phase transitions located at 214, 238, 434 and 477 K. The Raman and infrared spectra confirm the presence of both cationic [(C{sub 4}H{sub 9})N]{sup +} and anionic [Bi{sub 2}Cl{sub 9}]{sup 3−} parts. The dielectric parameters, real and imaginary dielectric permittivity (ε′ and ε″), and dielectric loss tangent (tg δ), were measured in the frequency range of 209 kHz–5 MHz at different temperatures. The variations of dielectric dispersion (ε') and dielectric absorption (ε″) with frequency show a distribution of relaxation times, which is probably related to the change in the dynamical state of the [(C{sub 4}H{sub 9}){sub 4}N]{sup +} cations and the [Bi{sub 2}Cl{sub 9}]{sup 3−} anions. - Graphical abstract: Projection of the atomic arrangement of the [(C{sub 4}H{sub 9}){sub 4}N]{sub 3}Bi{sub 2}Cl{sub 9} compound along the b axis. - Highlights: • The structure of the (TBA){sub 3}Bi{sub 2}Cl{sub 9} compound was solved and reported. • The cristal belongs to the monoclinic system with P2{sub 1}/n space group. • DSC discloses four order–disorder reversible phases transitions. • The temperature-dependent permittivity ε' and ε″ has been investigated.

The structures of bacteriophages K1E and K1-5 explain processive degradation of polysaccharide capsules and evolution of new host specificities.

Science.gov (United States)

Leiman, Petr G; Battisti, Anthony J; Bowman, Valorie D; Stummeyer, Katharina; Mühlenhoff, Martina; Gerardy-Schahn, Rita; Scholl, Dean; Molineux, Ian J

2007-08-17

External polysaccharides of many pathogenic bacteria form capsules protecting the bacteria from the animal immune system and phage infection. However, some bacteriophages can digest these capsules using glycosidases displayed on the phage particle. We have utilized cryo-electron microscopy to determine the structures of phages K1E and K1-5 and thereby establish the mechanism by which these phages attain and switch their host specificity. Using a specific glycosidase, both phages penetrate the capsule and infect the neuroinvasive human pathogen Escherichia coli K1. In addition to the K1-specific glycosidase, each K1-5 particle carries a second enzyme that allows it to infect E. coli K5, whose capsule is chemically different from that of K1. The enzymes are organized into a multiprotein complex attached via an adapter protein to the virus portal vertex, through which the DNA is ejected during infection. The structure of the complex suggests a mechanism for the apparent processivity of degradation that occurs as the phage drills through the polysaccharide capsule. The enzymes recognize the adapter protein by a conserved N-terminal sequence, providing a mechanism for phages to acquire different enzymes and thus to evolve new host specificities.

Highly efficient tandem OLED based on C{sub 60}/rubrene: MoO{sub 3} as charge generation layer and LiF/Al as electron injection layer

Energy Technology Data Exchange (ETDEWEB)

Liu, Yang [School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384 (China); Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin 300384 (China); Tianjin Key Laboratory of Photoelectric Materials and Devices, Tianjin 300384 (China); College of Science, Tianjin University of Technology, Tianjin 300384 (China); Wu, Xiaoming, E-mail: wxm@tjut.edu.cn [School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384 (China); Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin 300384 (China); Tianjin Key Laboratory of Photoelectric Materials and Devices, Tianjin 300384 (China); Xiao, Zhihui; Gao, Jian; Zhang, Juan; Rui, Hongsong; Lin, Xin; Zhang, Nan; Hua, Yulin [School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384 (China); Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin 300384 (China); Tianjin Key Laboratory of Photoelectric Materials and Devices, Tianjin 300384 (China); Yin, Shougen, E-mail: sgyin@tjut.edu.cn [School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384 (China); Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin 300384 (China); Tianjin Key Laboratory of Photoelectric Materials and Devices, Tianjin 300384 (China)

2017-08-15

Highlights: • Highly efficient blue fluorescent tandem OLEDs are fabricated. • The optimal tandem OLED consists of C{sub 60}/rubrene: MoO{sub 3} as a CGL and LiF/Al as an EIL. • Current efficiency and power efficiency of optimal tandem OLED is markedly enhanced. • The turn-on and driving voltages of optimal tandem OLED is obviously reduced. - Abstract: Tandem organic light-emitting diodes (OLEDs) have received much attention in solid-state lighting due to their high current efficiency, long lifetime and excellent stability. The highly efficient blue fluorescent tandem OLEDs based on the charge generation layer (CGL) of C{sub 60}/rubrene: MoO{sub 3} and the electron injection layer (EIL) of LiF/Al were fabricated. The ultra-thin Al layer in EIL was introduced to further increase electron injection from CGL to the emission unit. We found that the maximal current efficiency and power efficiency of optimal tandem device can reach to 43.1 cd/A and 15.1 lm/W, respectively, which are approximately 2.8 and 1.9 times compared with those of single-emissive-unit device. Moreover, compared with the traditional tandem device, the driving voltage of the optimal device is reduced by 6 V, and the turn-on voltage is reduced by 2.4 V. We analyzed the mechanism and characterization of these tandem devices. The effective charge separation and transport of C{sub 60}/rubrene: MoO{sub 3}, and excellent electron injection ability of ultra-thin Al layer are the main factors for the remarkable enhancement in both current efficiency and power efficiency of tandem OLEDs.

Staphylococcus aureus utilizes host-derived lipoprotein particles as sources of exogenous fatty acids.

Science.gov (United States)

Delekta, Phillip C; Shook, John C; Lydic, Todd A; Mulks, Martha H; Hammer, Neal D

2018-03-26

Methicillin-resistant Staphylococcus aureus (MRSA) is a threat to global health. Consequently, much effort has focused on the development of new antimicrobials that target novel aspects of S. aureus physiology. Fatty acids are required to maintain cell viability, and bacteria synthesize fatty acids using the type II fatty acid synthesis pathway (FASII). FASII is significantly different from human fatty acid synthesis, underscoring the therapeutic potential of inhibiting this pathway. However, many Gram-positive pathogens incorporate exogenous fatty acids, bypassing FASII inhibition and leaving the clinical potential of FASII inhibitors uncertain. Importantly, the source(s) of fatty acids available to pathogens within the host environment remains unclear. Fatty acids are transported throughout the body by lipoprotein particles in the form of triglycerides and esterified cholesterol. Thus, lipoproteins, such as low-density lipoprotein (LDL) represent a potentially rich source of exogenous fatty acids for S. aureus during infection. We sought to test the ability of LDLs to serve as a fatty acid source for S. aureus and show that cells cultured in the presence of human LDLs demonstrate increased tolerance to the FASII inhibitor, triclosan. Using mass spectrometry, we observed that host-derived fatty acids present in the LDLs are incorporated into the staphylococcal membrane and that tolerance to triclosan is facilitated by the fatty acid kinase A, FakA, and Geh, a triacylglycerol lipase. Finally, we demonstrate that human LDLs support the growth of S. aureus fatty acid auxotrophs. Together, these results suggest that human lipoprotein particles are a viable source of exogenous fatty acids for S. aureus during infection. IMPORTANCE Inhibition of bacterial fatty acid synthesis is a promising approach to combating infections caused by S. aureus and other human pathogens. However, S. aureus incorporates exogenous fatty acids into its phospholipid bilayer. Therefore, the

Effect of M{sub 3}C on the precipitation behavior of M{sub 23}C{sub 6} phase during early stage of tempering in T91 ferritic steel

Energy Technology Data Exchange (ETDEWEB)

Liu, Chenxi; Liu, Yongchang; Zhang, Dantian; Ning, Baoqun; Yan, Zesheng [School of Material Science and Engineering, Tianjin Key Laboratory of Advanced Jointing Technology, Tianjin University, Tianjin (China)

2011-12-15

Tempered martensitic structure is the service condition of T91 ferritic steel after adopting the austenitizing followed by tempering. Needle-like M{sub 3}C particles are precipitated during air cooling after austenization, while the precipitation of M{sub 3}C is suppressed during the water cooling. The effect of existence of M{sub 3}C on the precipitation behaviors of M{sub 23}C{sub 6} during the early stage of tempering, as nucleation site, number density and size distribution, was investigated by means of TEM observation. The TEM results indicate that, upon the same tempering time, the size of M{sub 23}C{sub 6} is smaller and its number density is higher in the sample pre-existing M{sub 3}C than in the sample without M{sub 3}C. This can be explained that existence of M{sub 3}C results in more M{sub 23}C{sub 6} precipitates forming inside of grain, where a relatively low self-diffusion coefficient of alloy element leads to M{sub 23}C{sub 6} hardly coarsening. However, with the prolongation of tempering time, this effect becomes weaken. Microhardness results indicate that the existence of M{sub 3}C phase results in the increase of hardness after tempering due to the precipitation of finer and denser M{sub 23}C{sub 6} particles. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Transient and modulated charge separation at CuInSe{sub 2}/C{sub 60} and CuInSe{sub 2}/ZnPc hybrid interfaces

Energy Technology Data Exchange (ETDEWEB)

Morzé, Natascha von, E-mail: natascha.von_morze@helmholtz-berlin.de; Dittrich, Thomas, E-mail: dittrich@helmholtz-berlin.de; Calvet, Wolfram, E-mail: wolfram.calvet@helmholtz-berlin.de; Lauermann, Iver, E-mail: iver.lauermann@helmholtz-berlin.de; Rusu, Marin, E-mail: rusu@helmholtz-berlin.de

2017-02-28

Highlights: • Surface physical properties of non- and Na-treated CuInSe{sub 2} layers studied. • Evidence of exciton dissociation and charge separation at CuInSe{sub 2}/ZnPc interface. • Strong band bending at the CuInSe{sub 2} surface in contact with C{sub 60} observed. • No evidence for exciton dissociation at the CuInSe{sub 2}/C{sub 60} interface found. • Cu-poor phase at CuInSe{sub 2}/organic interface crucial for charge separation. - Abstract: Spectral dependent charge transfer and exciton dissociation have been investigated at hybrid interfaces between inorganic polycrystalline CuInSe{sub 2} (untreated and Na-conditioned) thin films and organic C{sub 60} as well as zinc phthalocyanine (ZnPc) layers by transient and modulated surface photovoltage measurements. The stoichiometry and electronic properties of the bare CuInSe{sub 2} surface were characterized by photoelectron spectroscopy which revealed a Cu-poor phase with n-type features. After the deposition of the C{sub 60} layer, a strong band bending at the CuInSe{sub 2} surface was observed. Evidence for dissociation of excitons followed by charge separation was found at the CuInSe{sub 2}/ZnPc interface. The Cu-poor layer at the CuInSe{sub 2} surface was found to be crucial for transient and modulated charge separation at CuInSe{sub 2}/organic hybrid interfaces.

Chemistry through cocrystals: pressure-induced polymerization of C>2H₂·C₆H₆ to an extended crystalline hydrocarbon

Energy Technology Data Exchange (ETDEWEB)

Ward, Matthew D. [Geophysical Laboratory; Carnegie Institution of Washington; Washington; USA; Huang, Haw-Tyng [Department of Materials Science and Engineering; Pennsylvania State University; University Park; USA; Zhu, Li [Geophysical Laboratory; Carnegie Institution of Washington; Washington; USA; Biswas, Arani [Department of Chemistry; Pennsylvania State University; University Park; USA; Popov, Dmitry [High Pressure Collaborative Access Team (HPCAT); Geophysical Laboratory; Carnegie Institution of Washington; Argonne; USA; Badding, John V. [Department of Materials Science and Engineering; Pennsylvania State University; University Park; USA; Department of Chemistry; Strobel, Timothy A. [Geophysical Laboratory; Carnegie Institution of Washington; Washington; USA

2018-01-01

The 1 : 1 acetylene–benzene cocrystal, C>2H₂·C₆H₆, was synthesized under pressure in a diamond anvil cell (DAC) and its evolution under pressure was studied with single-crystal X-ray diffraction and Raman spectroscopy.

Chemistry through cocrystals: pressure-induced polymerization of C>2H₂·C ₆H₆ to an extended crystalline hydrocarbon

Energy Technology Data Exchange (ETDEWEB)

Ward, Matthew D. [Geophysical Laboratory; Carnegie Institution of Washington; Washington; USA; Huang, Haw-Tyng [Department of Materials Science and Engineering; Pennsylvania State University; University Park; USA; Zhu, Li [Geophysical Laboratory; Carnegie Institution of Washington; Washington; USA; Biswas, Arani [Department of Chemistry; Pennsylvania State University; University Park; USA; Popov, Dmitry [High Pressure Collaborative Access Team (HPCAT); Geophysical Laboratory; Carnegie Institution of Washington; Argonne; USA; Badding, John V. [Department of Materials Science and Engineering; Pennsylvania State University; University Park; USA; Department of Chemistry; Strobel, Timothy A. [Geophysical Laboratory; Carnegie Institution of Washington; Washington; USA

2018-01-01

The 1:1 acetylene–benzene cocrystal, C>2H₂·C₆H₆, was synthesized under pressure in a diamond anvil cell (DAC) and its evolution under pressure was studied with single-crystal X-ray diffraction and Raman spectroscopy.

Mechanism of propylene oxidation over bismuth molybdate revealed by transient response method--1. An intermediate in the complete oxidation of C/sub 3/H/sub 6/

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, M.; Futaya, R.

1979-01-01

An intermediate in the complete oxidation of C/sub 3/H/sub 6/ and its nature were deduced from transient response studies of a flow reactor system with a 1:1 bismuth-molybdenum catalyst at temperatures below ordinary operating temperatures. The formation of a stable surface intermediate with a non-allylic structure resembling that of propylene on every site of the catalyst surface occurred at 310/sup 0/C in the presence of propylene/oxygen or acrolein/oxygen; under oxidative conditions at 310/sup 0/C about eight times more intermediate formed directly from propylene than from adsorbed acrolein. The intermediate reacted with weakly adsorbed oxygen from the gas phase, but not with lattice oxygen, to decompose into CO/sub 2/; in temperature programed desorption studies (2.3/sup 0/C/min) it desorbed as CO/sub 2/ into a stream of helium above 220/sup 0/C (peak at 420/sup 0/C), apparently by reaction with oxygen diffused from the bulk to the surface.

Analysis of Host-Takeover During SPO1 Infection of Bacillus subtilis.

Science.gov (United States)

Stewart, Charles R

2018-01-01

When Bacillus subtilis is infected by bacteriophage SPO1, the phage directs the remodeling of the host cell, converting it into a factory for phage reproduction. Much synthesis of host DNA, RNA, and protein is shut off, and cell division is prevented. Here I describe the protocols by which we have demonstrated those processes, and identified the roles played by specific SPO1 gene products in causing those processes.

The potential for host switching via ecological fitting in the emerald ash borer-host plant system.

Science.gov (United States)

Cipollini, Don; Peterson, Donnie L

2018-02-27

The traits used by phytophagous insects to find and utilize their ancestral hosts can lead to host range expansions, generally to closely related hosts that share visual and chemical features with ancestral hosts. Host range expansions often result from ecological fitting, which is the process whereby organisms colonize and persist in novel environments, use novel resources, or form novel associations with other species because of the suites of traits that they carry at the time they encounter the novel environment. Our objective in this review is to discuss the potential and constraints on host switching via ecological fitting in emerald ash borer, Agrilus planipennis, an ecologically and economically important invasive wood boring beetle. Once thought of as an ash (Fraxinus spp.) tree specialist, recent studies have revealed a broader potential host range than was expected for this insect. We discuss the demonstrated host-use capabilities of this beetle, as well as the potential for and barriers to the adoption of additional hosts by this beetle. We place our observations in the context of biochemical mechanisms that mediate the interaction of these beetles with their host plants and discuss whether evolutionary host shifts are a possible outcome of the interaction of this insect with novel hosts.

Host-detrimental role of Esx-1-mediated inflammasome activation in mycobacterial infection.

Directory of Open Access Journals (Sweden)

Fredric Carlsson

2010-05-01

Full Text Available The Esx-1 (type VII secretion system is a major virulence determinant of pathogenic mycobacteria, including Mycobacterium marinum. However, the molecular events and host-pathogen interactions underlying Esx-1-mediated virulence in vivo remain unclear. Here we address this problem in a non-lethal mouse model of M. marinum infection that allows detailed quantitative analysis of disease progression. M. marinum established local infection in mouse tails, with Esx-1-dependent formation of caseating granulomas similar to those formed in human tuberculosis, and bone deterioration reminiscent of skeletal tuberculosis. Analysis of tails infected with wild type or Esx-1-deficient bacteria showed that Esx-1 enhanced generation of proinflammatory cytokines, including the secreted form of IL-1beta, suggesting that Esx-1 promotes inflammasome activation in vivo. In vitro experiments indicated that Esx-1-dependent inflammasome activation required the host NLRP3 and ASC proteins. Infection of wild type and ASC-deficient mice demonstrated that Esx-1-dependent inflammasome activation exacerbated disease without restricting bacterial growth, indicating a host-detrimental role of this inflammatory pathway in mycobacterial infection. These findings define an immunoregulatory role for Esx-1 in a specific host-pathogen interaction in vivo, and indicate that the Esx-1 secretion system promotes disease and inflammation through its ability to activate the inflammasome.

Effects of CO/sub 2/ enrichment and temperature on growth in two C/sub 4/ weeds, Echinochloa crus-galli and Eleusine indica

Energy Technology Data Exchange (ETDEWEB)

Potvin, C.; Strain, B.R.

1985-01-01

Mathematical growth analyses were carried out on two C/sub 4/ grasses, Echinochloa crus-galli and Eleusine indica, to test the influence of CO/sub 2/ enrichment and temperature on growth. Echinochloa populations from Quebec, North Carolina, and Mississippi and a single population of Eleusine from Mississippi were grown for 48 days at two CO/sub 2/ concentrations (350 and 675 ..mu..L/center dot/L/sup /minus/1/) and three temperature regimes (28:22, 24:18, and 21: 15/degree/C). CO/sub 2/ enrichment generated an increased root dry weight and induced an earlier development of inflorescences. Net assimilation rate, the only other parameter to respond to CO/sub 2/ enrichment, was higher for plants grown at high CO/sub 2/ concentration during the first harvest interval. Biomass partitioning was affected by temperature. Root dry weight was greater in plants grown at 21:15/degree/C while more leaf area was produced in warmer temperature regimes. Only plants from Quebec maintained normal growth rates under the 21:15/degree/C regime, suggesting that northern C/sub 4/ plants are better suited for growth at low temperatures than southern ones. 18 refs., 2 figs., 3 tabs.

Interaction between fullerene halves C{sub n} (n ≤ 40) and single wall carbon nanotube

Energy Technology Data Exchange (ETDEWEB)

Sharma, Amrish, E-mail: amrish99@gmail.com; Kaur, Sandeep, E-mail: sipusukhn@gmail.com [Department of Physics, Punjabi University, Patiala (India); Mudahar, Isha, E-mail: isha@pbi.ac.in [Department of Basic and Applied Sciences, Punjabi University, Patiala (India)

2016-05-06

We have investigated the structural and electronic properties of carbon nanotube with small fullerene halves C{sub n} (n ≤ 40) which are covalently bonded to the side wall of an armchair single wall carbon nanotube (SWCNT) using first principle method based on density functional theory. The fullerene size results in weak bonding between fullerene halves and carbon nanotube (CNT). Further, it was found that the C-C bond distance that attaches the fullerene half and CNT is of the order of 1.60 Å. The calculated binding energies indicate the stability of the complexes formed. The HOMO-LUMO gaps and electron density of state plots points towards the metallicity of the complex formed. Our calculations on charge transfer reveal that very small amount of charge is transferred from CNT to fullerene halves.

The Csub(N) method in cylindrical geometry and one-velocity theory

International Nuclear Information System (INIS)

Kavenoky, A.

1975-01-01

The Csub(N) method of solving the transport equation has been developed at Saclay during the last few years: its main advantage is that the computing time is independent of the size of the media considered. This method is based on a lemma proved by Placzek: an integral equation is provided for the angular flux at the boundaries of the media, its kernel is the infinite medium Green's function. The knowledge of the angular flux at the boundaries of the media allows the fluxes to be calculated at any point. The report is devoted to the application to classical problems in one velocity cylindrical geometry: albedo of the inner and outer problems, extrapolation length for the Milne problem, critical radius [fr

26 CFR 1.42-10 - Utility allowances.

Science.gov (United States)

2010-04-01

... Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY INCOME TAX INCOME TAXES Credits Against Tax § 1.42-10 Utility allowances. (a) Inclusion of utility allowances in gross rent. If the cost.... (b) Applicable utility allowances—(1) Buildings assisted by the Rural Housing Service. If a building...

The role of interleukin-1 family members in the host defence against Aspergillus fumigatus.

Science.gov (United States)

Gresnigt, Mark S; van de Veerdonk, Frank L

2014-12-01

The interleukin (IL)-1 family consists of 11 members, which all play significant roles in regulating inflammatory responses in the host. IL-1α and IL-1β exert potent pro-inflammatory effects and are key players in the recruitment of neutrophils to the site of inflammation. Protective anti-Aspergillus host responses during the early stages of invasive aspergillosis are critically dependent on neutrophil recruitment, and several lines of evidence support that there is an important role for IL-1 in this process. However, IL-1-mediated inflammation needs to be tightly regulated, since uncontrolled inflammation can result in inflammatory pathology and thereby be detrimental for the host. Aspergillus-induced IL-1-mediated inflammation could therefore be amendable for IL-1 blockade under specific circumstances. This review describes the current understanding of the role of IL-1 family members in the host response against Aspergillus fumigatus and highlights the importance of balanced IL-1 responses in aspergillosis.

Electronic origin of spatial self-phase modulation: Evidenced by comparing graphite with C{sub 60} and graphene

Energy Technology Data Exchange (ETDEWEB)

Wu, Y. L.; Zhu, L. L. [College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300071 (China); Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wu, Q.; Sun, F.; Wei, J. K.; Tian, Y. C.; Wang, W. L.; Bai, X. D.; Zhao, Jimin, E-mail: jmzhao@iphy.ac.cn, E-mail: xzuonku@outlook.com [Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zuo, Xu, E-mail: jmzhao@iphy.ac.cn, E-mail: xzuonku@outlook.com [College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300071 (China)

2016-06-13

We report unambiguous observation of spatial self-phase modulation (SSPM) in a dispersive suspension of graphite flakes. This coherent nonlinear optical effect in bulk graphite is found to be broadband and large, with a third-order nonlinear susceptibility χ{sup (3)} of 2.2 × 10{sup −9} esu (i.e., 3.1 × 10{sup −17} m{sup 2}/V{sup 2} in SI units) at 532 nm excitation. Comparison with other carbon allotropes shows that this value is 5 × 10{sup 7} times higher than that of C{sub 60} but ∼50 times lower than that of graphene, fully exhibiting the electronic origin of SSPM.

Effects of La{sub 2}O{sub 3} on microstructure and wear properties of laser clad {gamma}/Cr{sub 7}C{sub 3}/TiC composite coatings on TiAl intermatallic alloy

Energy Technology Data Exchange (ETDEWEB)

Liu Xiubo [Laboratory for Laser Intelligent Manufacturing, Institute of Mechanics, Chinese Academy of Sciences, 15 Beisihuanxi Road, Beijing 100080 (China) and School of Materials and Chemical Engineering, Zhongyuan Institute of Technology, 41 Zhongyuan Western Road, Zhengzhou 450007, Henan Province (China)]. E-mail: liubobo0828@yahoo.com.cn; Yu Rongli [School of Materials Science and Engineering, Beihang University, 37 Xueyuan Road, Beijing 100083 (China)

2007-02-15

The effects of La{sub 2}O{sub 3} addition on the microstructure and wear properties of laser clad {gamma}/Cr{sub 7}C{sub 3}/TiC composite coatings on {gamma}-TiAl intermetallic alloy substrates with NiCr-Cr{sub 3}C{sub 2} precursor mixed powders have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy-dispersive spectrometer (EDS) and block-on-ring wear tests. The responding wear mechanisms are discussed in detail. The results are compared with that for composite coating without La{sub 2}O{sub 3}. The comparison indicates that no evident new crystallographic phases are formed except a rapidly solidified microstructure consisting of the primary hard Cr{sub 7}C{sub 3} and TiC carbides and the {gamma}/Cr{sub 7}C{sub 3} eutectics distributed in the tough {gamma} nickel solid solution matrix. Good finishing coatings can be achieved under a proper amount of La{sub 2}O{sub 3}-addition and a suitable laser processing parameters. The additions of rare-earth oxide La{sub 2}O{sub 3} can refine and purify the microstructure of coatings, relatively decrease the volume fraction of primary blocky Cr{sub 7}C{sub 3} to Cr{sub 7}C{sub 3}/{gamma} eutectics, reduce the dilution of clad material from base alloy and increase the microhardness of the coatings. When the addition of La{sub 2}O{sub 3} is approximately 4 wt.%, the laser clad composite coating possesses the highest hardness and toughness. The composite coating with 4 wt.%La{sub 2}O{sub 3} addition can result the best enhancement of wear resistance of about 30%. However, too less or excessive addition amount of La{sub 2}O{sub 3} have no better influence on wear resistance of the composite coating.

HostPhinder: A Phage Host Prediction Tool

Directory of Open Access Journals (Sweden)

Julia Villarroel

2016-05-01

Full Text Available The current dramatic increase of antibiotic resistant bacteria has revitalised the interest in bacteriophages as alternative antibacterial treatment. Meanwhile, the development of bioinformatics methods for analysing genomic data places high-throughput approaches for phage characterization within reach. Here, we present HostPhinder, a tool aimed at predicting the bacterial host of phages by examining the phage genome sequence. Using a reference database of 2196 phages with known hosts, HostPhinder predicts the host species of a query phage as the host of the most genomically similar reference phages. As a measure of genomic similarity the number of co-occurring k-mers (DNA sequences of length k is used. Using an independent evaluation set, HostPhinder was able to correctly predict host genus and species for 81% and 74% of the phages respectively, giving predictions for more phages than BLAST and significantly outperforming BLAST on phages for which both had predictions. HostPhinder predictions on phage draft genomes from the INTESTI phage cocktail corresponded well with the advertised targets of the cocktail. Our study indicates that for most phages genomic similarity correlates well with related bacterial hosts. HostPhinder is available as an interactive web service [1] and as a stand alone download from the Docker registry [2].

Distinct temporal roles for the promyelocytic leukaemia (PML protein in the sequential regulation of intracellular host immunity to HSV-1 infection.

Directory of Open Access Journals (Sweden)

Thamir Alandijany

2018-01-01

Full Text Available Detection of viral nucleic acids plays a critical role in the induction of intracellular host immune defences. However, the temporal recruitment of immune regulators to infecting viral genomes remains poorly defined due to the technical difficulties associated with low genome copy-number detection. Here we utilize 5-Ethynyl-2'-deoxyuridine (EdU labelling of herpes simplex virus 1 (HSV-1 DNA in combination with click chemistry to examine the sequential recruitment of host immune regulators to infecting viral genomes under low multiplicity of infection conditions. Following viral genome entry into the nucleus, PML-nuclear bodies (PML-NBs rapidly entrapped viral DNA (vDNA leading to a block in viral replication in the absence of the viral PML-NB antagonist ICP0. This pre-existing intrinsic host defence to infection occurred independently of the vDNA pathogen sensor IFI16 (Interferon Gamma Inducible Protein 16 and the induction of interferon stimulated gene (ISG expression, demonstrating that vDNA entry into the nucleus alone is not sufficient to induce a robust innate immune response. Saturation of this pre-existing intrinsic host defence during HSV-1 ICP0-null mutant infection led to the stable recruitment of PML and IFI16 into vDNA complexes associated with ICP4, and led to the induction of ISG expression. This induced innate immune response occurred in a PML-, IFI16-, and Janus-Associated Kinase (JAK-dependent manner and was restricted by phosphonoacetic acid, demonstrating that vDNA polymerase activity is required for the robust induction of ISG expression during HSV-1 infection. Our data identifies dual roles for PML in the sequential regulation of intrinsic and innate immunity to HSV-1 infection that are dependent on viral genome delivery to the nucleus and the onset of vDNA replication, respectively. These intracellular host defences are counteracted by ICP0, which targets PML for degradation from the outset of nuclear infection to promote v

A new imidazolium-embedded C{sub 18} stationary phase with enhanced performance in reversed-phase liquid chromatography

Energy Technology Data Exchange (ETDEWEB)

Qiu Hongdeng [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000 (China); Mallik, Abul K. [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Takafuji, Makoto [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), Kumamoto 862-0901 (Japan); Liu Xia; Jiang Shengxiang [Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000 (China); Ihara, Hirotaka, E-mail: ihara@kumamoto-u.ac.jp [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), Kumamoto 862-0901 (Japan)

2012-08-13

Highlights: Black-Right-Pointing-Pointer Imidazolium-embedded C{sub 18} stationary phase was prepared and characterized. Black-Right-Pointing-Pointer Enhanced chromatographic selectivity was observed in SiImC{sub 18} column. Black-Right-Pointing-Pointer Seven nucleosides and bases were separated using only water as eluent within 8 min. Black-Right-Pointing-Pointer Multiple-interactions induced by embedded polar imidazolium was investigated. - Abstract: In this paper, a new imidazolium-embedded C{sub 18} stationary phase (SiImC{sub 18}) for reversed-phase high-performance liquid chromatography is described. 1-Allyl-3-octadecylimidazolium bromide ionic liquid compound having a long alkyl chain and reactive groups was newly prepared and grafted onto 3-mercaptopropyltrimethoxysilane-modified silica via a surface-initiated radical-chain transfer addition reaction. The SiImC{sub 18} obtained was characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, diffuse reflectance infrared Fourier transform, and solid-state {sup 13}C and {sup 29}Si cross-polarization/magic angle spinning nuclear magnetic resonance spectroscopy. The selectivity toward polycyclic aromatic hydrocarbons relative to that toward alkylbenzenes exhibited by SiImC{sub 18} was higher than the corresponding selectivity exhibited by a conventional octadecyl silica (ODS) column, which could be explained by electrostatic {pi}-{pi} interaction cationic imidazolium and electron-rich aromatic rings. On the other hand, SiImC{sub 18} also showed high selectivity for polar compounds, which was based on the multiple interaction and retention mechanisms of this phase with different analytes. 1,6-Dinitropyrene and 1,8-dinitropyrene, which form a positional isomer pair of dipolar compounds, were separated successfully with the SiImC{sub 18} phase. Seven nucleosides and bases (i.e. cytidine, uracil, uridine, thymine, guanosine, xanthosine, and adenosine) were separated using only water as

TEMPO functionalized C{sub 60} fullerene deposited on gold surface for catalytic oxidation of selected alcohols

Energy Technology Data Exchange (ETDEWEB)

Piotrowski, Piotr; Pawłowska, Joanna [University of Warsaw, Department of Chemistry (Poland); Sadło, Jarosław Grzegorz [Institute of Nuclear Chemistry and Technology (Poland); Bilewicz, Renata; Kaim, Andrzej, E-mail: akaim@chem.uw.edu.pl [University of Warsaw, Department of Chemistry (Poland)

2017-05-15

C{sub 60}TEMPO{sub 10} catalytic system linked to a microspherical gold support through a covalent S-Au bond was developed. The C{sub 60}TEMPO{sub 10}@Au composite catalyst had a particle size of 0.5–0.8 μm and was covered with the fullerenes derivative of 2.3 nm diameter bearing ten nitroxyl groups; the organic film showed up to 50 nm thickness. The catalytic composite allowed for the oxidation under mild conditions of various primary and secondary alcohols to the corresponding aldehyde and ketone analogues with efficiencies as high as 79–98%, thus giving values typical for homogeneous catalysis, while retaining at the same time all the advantages of heterogeneous catalysis, e.g., easy separation by filtration from the reaction mixture. The catalytic activity of the resulting system was studied by means of high pressure liquid chromatography. A redox mechanism was proposed for the process. In the catalytic cycle of the oxidation process, the TEMPO moiety was continuously regenerated in situ with an applied primary oxidant, for example, O{sub 2}/Fe{sup 3+} system. The new intermediate composite components and the final catalyst were characterized by various spectroscopic methods and thermogravimetry.

Effect of processing parameters on the formation of C{sub f}/LAS composites/Ag−Cu−Ti/TC4 brazed joint

Energy Technology Data Exchange (ETDEWEB)

Liu, Duo; Niu, Hongwei [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); Liu, Jihou [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Song, Xiaoguo, E-mail: songxg@hitwh.edu.cn [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Xia, Long [School of Materials Science and Engineering, Harbin Institute of Technology at Weihai, Weihai 264209 (China); Feng, Jicai [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)

2016-10-15

C{sub f}/LAS composites were successfully jointed to TC4 alloy with Ag−Cu−Ti filler by vacuum brazing. The interfacial microstructure of TC4/C{sub f}/LAS composites joints was characterized by employing scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-diffraction (XRD) and transmission electron microscopy (TEM). The determination of the thin interfacial reaction layer (TiSi{sub 2} + TiC layer) was realized by TEM. The effect of holding time on the interfacial microstructure and shear strength were investigated. With the increasing holding time, the thickness of diffusion layer, Ti{sub 3}Cu{sub 4} layer, and TiSi{sub 2} + TiC layer increased obviously, on the contrary, that of Ti−Cu intermetallic compound layers decreased gradually. Besides, blocky Ti{sub 3}Cu{sub 4} phase was coarsened when the joint was brazed at 890 °C for 20 min, which deteriorated the mechanical properties of the joint dramatically. The interfacial evolution of TC4/C{sub f}/LAS composites joint and the formation of TiSi{sub 2}, TiC, Ti{sub 3}Cu{sub 4}, TiCu and Ti{sub 2}Cu phases were expounded. The maximum shear strength of 26.4 MPa was obtained when brazed at 890 °C for 10 min. - Highlights: •The thin interface reaction layer was determined to be TiSi{sub 2} + TiC layer by TEM. •Holding time had influence on the interfacial microstructure and joint properties. •Microstructural evolution mechanism and reactions of brazed joints were expounded.

KSHV strategies for host dsDNA sensing machinery.

Science.gov (United States)

Gao, Hang; Song, Yanyan; Liu, Chengrong; Liang, Qiming

2016-12-01

The innate immune system utilizes pattern recognition receptors cyclic GMP-AMP synthase (cGAS) to sense cytosolic double-stranded (ds) DNA and initiate type 1 interferon signaling and autophagy pathway, which collaborate to limit pathogen infections as well as alarm the adaptive immune response. The genomes of herpesviruses are large dsDNA, which represent a major class of pathogen signatures recognized by cellular DNA sensor cGAS. However, to successfully establish the persistent infection, herpesviruses have evolved their viral genes to modulate different aspects of host immune signaling. This review summarizes the evasion strategies of host cGAS DNA sensing pathway by Kaposi's Sarcoma-associated Herpesvirus (KSHV) and their contributions to KSHV life cycles.

Truncation of a P1 leader proteinase facilitates potyvirus replication in a non-permissive host.

Science.gov (United States)

Shan, Hongying; Pasin, Fabio; Tzanetakis, Ioannis E; Simón-Mateo, Carmen; García, Juan Antonio; Rodamilans, Bernardo

2017-11-08

The Potyviridae family is a major group of plant viruses that includes c. 200 species, most of which have narrow host ranges. The potyvirid P1 leader proteinase self-cleaves from the remainder of the viral polyprotein and shows large sequence variability linked to host adaptation. P1 proteins can be classified as Type A or Type B on the basis, amongst other things, of their dependence or not on a host factor to develop their protease activity. In this work, we studied Type A proteases from the Potyviridae family, characterizing their host factor requirements. Our in vitro cleavage analyses of potyvirid P1 proteases showed that the N-terminal domain is relevant for host factor interaction and suggested that the C-terminal domain is also involved. In the absence of plant factors, the N-terminal end of Plum pox virus P1 antagonizes protease self-processing. We performed extended deletion mutagenesis analysis to define the N-terminal antagonistic domain of P1. In viral infections, removal of the P1 protease antagonistic domain led to a gain-of-function phenotype, strongly increasing local infection in a non-permissive host. Altogether, our results shed new insights into the adaptation and evolution of potyvirids. © 2017 BSPP AND JOHN WILEY & SONS LTD.

Orientia tsutsugamushi ankyrin repeat-containing protein family members are Type 1 secretion system substrates that traffic to the host cell endoplasmic reticulum.

Science.gov (United States)

VieBrock, Lauren; Evans, Sean M; Beyer, Andrea R; Larson, Charles L; Beare, Paul A; Ge, Hong; Singh, Smita; Rodino, Kyle G; Heinzen, Robert A; Richards, Allen L; Carlyon, Jason A

2014-01-01

Scrub typhus is an understudied, potentially fatal infection that threatens one billion persons in the Asia-Pacific region. How the causative obligate intracellular bacterium, Orientia tsutsugamushi, facilitates its intracellular survival and pathogenesis is poorly understood. Many intracellular bacterial pathogens utilize the Type 1 (T1SS) or Type 4 secretion system (T4SS) to translocate ankyrin repeat-containing proteins (Anks) that traffic to distinct subcellular locations and modulate host cell processes. The O. tsutsugamushi genome encodes one of the largest known bacterial Ank repertoires plus T1SS and T4SS components. Whether these potential virulence factors are expressed during infection, how the Anks are potentially secreted, and to where they localize in the host cell are not known. We determined that O. tsutsugamushi transcriptionally expresses 20 unique ank genes as well as genes for both T1SS and T4SS during infection of mammalian host cells. Examination of the Anks' C-termini revealed that the majority of them resemble T1SS substrates. Escherichia coli expressing a functional T1SS was able to secrete chimeric hemolysin proteins bearing the C-termini of 19 of 20 O. tsutsugamushi Anks in an HlyBD-dependent manner. Thus, O. tsutsugamushi Anks C-termini are T1SS-compatible. Conversely, Coxiella burnetii could not secrete heterologously expressed Anks in a T4SS-dependent manner. Analysis of the subcellular distribution patterns of 20 ectopically expressed Anks revealed that, while 6 remained cytosolic or trafficked to the nucleus, 14 localized to, and in some cases, altered the morphology of the endoplasmic reticulum. This study identifies O. tsutsugamushi Anks as T1SS substrates and indicates that many display a tropism for the host cell secretory pathway.

Quantifying host potentials: indexing postharvest fresh fruits for spotted wing Drosophila, Drosophila suzukii.

Directory of Open Access Journals (Sweden)

David E Bellamy

Full Text Available Novel methodology is presented for indexing the relative potential of hosts to function as resources. A Host Potential Index (HPI was developed as a practical framework to express relative host potential based on combining results from one or more independent studies, such as those examining host selection, utilization, and physiological development of the organism resourcing the host. Several aspects of the HPI are addressed including: 1 model derivation; 2 influence of experimental design on establishing host rankings for a study type (no choice, two-choice, and multiple-choice; and, 3 variable selection and weighting associated with combining multiple studies. To demonstrate application of the HPI, results from the interactions of spotted wing drosophila (SWD, Drosophila suzukii Matsumura (Diptera: Drosophilidae, with seven "reported" hosts (blackberries, blueberries, sweet cherries, table grapes, peaches, raspberries, and strawberries in a postharvest scenario were analyzed. Four aspects of SWD-host interaction were examined: attraction to host volatiles; population-level oviposition performance; individual-level oviposition performance; and key developmental factors. Application of HPI methodology indicated that raspberries ( (meanHPIvaried  = 301.9±8.39; rank 1 of 7 have the greatest potential to serve as a postharvest host for SWD relative to the other fruit hosts, with grapes ( (meanHPIvaried  = 232.4±3.21; rank 7 of 7 having the least potential.

Giant plasmon excitation in single and double ionization of C{sub 60} by fast highly charged Si and O ions

Energy Technology Data Exchange (ETDEWEB)

Kelkar, A H; Kadhane, U; Misra, D; Tribedi, L C [Tata Institute of Fundamental Research, Colaba, Mumbai-5 (India)

2007-09-15

Se have investigated single and double ionization of C{sub 60} molecule in collisions with 2.33 MeV/u Si{sup q+} (q=6-14) and 3.125 MeV/u O{sup q+} (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C{sub 60} are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening.

Structural phase transition causing anomalous photoluminescence behavior in perovskite (C{sub 6}H{sub 11}NH{sub 3}){sub 2}[PbI{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Yangui, A. [Groupe d’Etudes de la Matière Condensée, UMR CNRS 8653-Université de Versailles Saint Quentin En Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles (France); Laboratoire de Physique Appliquée, Faculté des Sciences de Sfax, Route de Soukra km 3.5 BP 1171, 3018 Sfax (Tunisia); Pillet, S. [Laboratoire de Cristallographie, Résonance Magnétique et Modélisations, UMR-CNRS 7036, Institut Jean Barriol, Université de Lorraine, BP 239, 54506 Vandoeuvre-lès-Nancy (France); Mlayah, A. [Centre d’Elaboration de Matériaux et d’Etudes Structurales (CEMES), CNRS UPR 8011-Université de Toulouse, 29 rue Jeanne Marvig 31055, Toulouse, Cedex 4 (France); Lusson, A.; Bouchez, G.; Boukheddaden, K., E-mail: Younes.abid@fss.rnu.tn, E-mail: kbo@physique.uvsq.fr [Groupe d’Etudes de la Matière Condensée, UMR CNRS 8653-Université de Versailles Saint Quentin En Yvelines, 45 Avenue des Etats-Unis, 78035 Versailles (France); Triki, S. [Laboratoire de Chimie, Electrochimie Moléculaires, Chimie Analytique, UMR CNRS 6521-Université de Bretagne Occidentale, BP 809, 29285 Brest (France); Abid, Y., E-mail: Younes.abid@fss.rnu.tn, E-mail: kbo@physique.uvsq.fr [Laboratoire de Physique Appliquée, Faculté des Sciences de Sfax, Route de Soukra km 3.5 BP 1171, 3018 Sfax (Tunisia)

2015-12-14

Optical and structural properties of the organic-inorganic hybrid perovskite-type (C{sub 6}H{sub 11}NH{sub 3}){sub 2}[PbI{sub 4}] (abbreviated as C{sub 6}PbI{sub 4}) were investigated using optical absorption, photoluminescence (PL), and x-ray diffraction measurements. Room temperature, optical absorption measurements, performed on spin-coated films of C{sub 6}PbI{sub 4}, revealed two absorption bands at 2.44 and 3.21 eV. Upon 325 nm (3.815 eV) laser irradiation, strong green PL emission peaks were observed at 2.41 eV (P1) and 2.24 eV (P2) and assigned to free and localized excitons, respectively. The exciton binding energy was estimated at 356 meV. At low temperature, two additional emission bands were detected at 2.366 eV (P3) and a large band (LB) at 1.97 eV. The former appeared only below 40 K and the latter emerged below 130 K. The thermal dependence of the PL spectra revealed an abnormal behavior accompanied by singularities in the peak positions and intensities at 40 and 130 K. X-ray diffraction studies performed on powder and single crystals as a function of temperature evidenced significant changes of the interlayer spacing at 50 K and ∼138 K. Around 138 K, a commensurate to incommensurate structural phase transition occurred on cooling. It involves a symmetry breaking leading to a distortion of the PbI{sub 6} octahedron. The resulting incommensurate spatial modulation of the Pb–I distances (and Pb–I–Pb angles) causes a spatial modulation of the band gap, which is at the origin of the emergence of the LB below ∼130 K and the anomalous behavior of the position of P1 below 130 K. The change of the interlayer spacing in the 40-50 K range may in turn be related to the significant decrease of the intensity of P2 and the maximum emission of the LB. These results underline the intricate character of the structural and the PL properties of the hybrid perovskites; understanding such properties should benefit to the design of optoelectronic devices with

/sup 1/H, /sup 13/C and /sup 31/P-NMR spectroscopic study of glucose metabolism of muscle larva Trichinella spiralis (U. S. A. strain), and the effects of the end-products on the host (mouse)

Energy Technology Data Exchange (ETDEWEB)

Nishina, Masami

1988-11-01

/sup 1/H- and /sup 13/C-nuclear magnetic resonance (NMR) spectroscopy was used to identify and quantitate metabolites excreted by muscle larva Trichinella spiralis maintained aerobically in the presence of D- (/sup 13/C/sub 6/) glucose and (1, 1'-/sup 13/C/sub 2/) succinate. End-products of glucose metabolism studied by /sup 1/H-NMR were lactate, acetate, succinate, proionate, n-valerate and alanine, at the molar ratio of 1:2:1:0.6:0.5:0.6. /sup 13/C-NMR measurement proved that all the products originated from the glucose in the medium via the phosphoenolpyruvate carboxykinase-succinate pathway and the tricarboxylic acid cycle. In vivo /sup 31/P-NMR spectra were also taken by the surface coil method from the leg muscle of mice which had been infected with T. spiralis. Intracelluar pH and relative amount of ATP in the leg muscle of the infected mice were found to decrease significantly as compared with that of control mice.

An integral parametrization of the bacterial growth curve experimental demonstration with E. coli C{sub 6}00 bacteria; Parametrizacion integrada de la curva de crecimiento bacteriano. Comprobacion experimental para E. coli C{sub 6}00

Energy Technology Data Exchange (ETDEWEB)

Garces, F; Vidania, R de

1984-07-01

In this work an integral parametrization of the bacterial growth curve is presented. The values of the parameters are obtained by fitting to the experimental data. Those parameters, with allow to describe the growth in its different phases, are the followings: slopes of the curve in its three parts and the time which divides the last two phases of the bacterial growth. The experimental data are bacterial densities measured by optical methods. The bacteria used was the E. coli C{sub 6}00. (Author)

Lipids in host-pathogen interactions: pathogens exploit the complexity of the host cell lipidome.

Science.gov (United States)

van der Meer-Janssen, Ynske P M; van Galen, Josse; Batenburg, Joseph J; Helms, J Bernd

2010-01-01

Lipids were long believed to have a structural role in biomembranes and a role in energy storage utilizing cellular lipid droplets and plasma lipoproteins. Research over the last decades has identified an additional role of lipids in cellular signaling, membrane microdomain organization and dynamics, and membrane trafficking. These properties make lipids an attractive target for pathogens to modulate host cell processes in order to allow their survival and replication. In this review we will summarize the often ingenious strategies of pathogens to modify the lipid homeostasis of host cells, allowing them to divert cellular processes. To this end pathogens take full advantage of the complexity of the lipidome. The examples are categorized in generalized and emerging principles describing the involvement of lipids in host-pathogen interactions. Several pathogens are described that simultaneously induce multiple changes in the host cell signaling and trafficking mechanisms. Elucidation of these pathogen-induced changes may have important implications for drug development. The emergence of high-throughput lipidomic techniques will allow the description of changes of the host cell lipidome at the level of individual molecular lipid species and the identification of lipid biomarkers.

Identification of highly brominated analogues of Q1 in marine mammals

Energy Technology Data Exchange (ETDEWEB)

Teuten, Emma L. [Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA 02543 (United States)]. E-mail: emma.teuten@plymouth.ac.uk; Pedler, Byron E. [Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA 02543 (United States)]. E-mail: bpedler@whoi.edu; Hangsterfer, Alexandra N. [Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA 02543 (United States)]. E-mail: ahangsterfer@whoi.edu; Reddy, Christopher M. [Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA 02543 (United States)]. E-mail: creddy@whoi.edu

2006-11-15

Three novel halogenated organic compounds (HOCs) have been identified in the blubber of marine mammals from coastal New England with the molecular formulae C{sub 9}H{sub 3}N{sub 2}Br{sub 6}Cl, C{sub 9}H{sub 3}N{sub 2}Br{sub 7}, and C{sub 9}H{sub 4}N{sub 2}Br{sub 5}Cl. They were identified using high and low resolution gas chromatography mass spectrometry (GCMS) and appear to be highly brominated analogues of Q1, a heptachlorinated HOC suspected to be naturally produced. These compounds were found in Atlantic white sided dolphin (Lagenorhynchus acutus), bottlenose dolphin (Tursiops truncatus), common dolphin (Delphinus delphis), Risso's dolphin (Grampus griseus), harbor porpoise (Phocoena phocoena), beluga whale (Delphinapterus leucas), fin whale (Balaenoptera physalus), grey seal (Halichoerus grypus), harp seal (Phoca groenlandica) and a potential food source (Loligo pealei) with concentrations as high as 2.7 {mu}g/g (lipid weight). The regiospecificity of C{sub 9}H{sub 3}N{sub 2}Br{sub 6}Cl is suggestive of a biogenic origin. Debromination of C{sub 9}H{sub 3}N{sub 2}Br{sub 6}Cl may be significant in the formation of C{sub 9}H{sub 4}N{sub 2}Br{sub 5}Cl. - Three novel bioaccumulated compounds were identified as C{sub 9}H{sub 3}N{sub 2}Br{sub 6}Cl, C{sub 9}H{sub 3}N{sub 2}Br{sub 7} and C{sub 9}H{sub 4}N{sub 2}Br{sub 5}Cl.

Interactions between the HIV-1 Unspliced mRNA and Host mRNA Decay Machineries

Directory of Open Access Journals (Sweden)

Daniela Toro-Ascuy

2016-11-01

Full Text Available The human immunodeficiency virus type-1 (HIV-1 unspliced transcript is used both as mRNA for the synthesis of structural proteins and as the packaged genome. Given the presence of retained introns and instability AU-rich sequences, this viral transcript is normally retained and degraded in the nucleus of host cells unless the viral protein REV is present. As such, the stability of the HIV-1 unspliced mRNA must be particularly controlled in the nucleus and the cytoplasm in order to ensure proper levels of this viral mRNA for translation and viral particle formation. During its journey, the HIV-1 unspliced mRNA assembles into highly specific messenger ribonucleoproteins (mRNPs containing many different host proteins, amongst which are well-known regulators of cytoplasmic mRNA decay pathways such as up-frameshift suppressor 1 homolog (UPF1, Staufen double-stranded RNA binding protein 1/2 (STAU1/2, or components of miRNA-induced silencing complex (miRISC and processing bodies (PBs. More recently, the HIV-1 unspliced mRNA was shown to contain N6-methyladenosine (m6A, allowing the recruitment of YTH N6-methyladenosine RNA binding protein 2 (YTHDF2, an m6A reader host protein involved in mRNA decay. Interestingly, these host proteins involved in mRNA decay were shown to play positive roles in viral gene expression and viral particle assembly, suggesting that HIV-1 interacts with mRNA decay components to successfully accomplish viral replication. This review summarizes the state of the art in terms of the interactions between HIV-1 unspliced mRNA and components of different host mRNA decay machineries.

Communication: The H{sub 2}@C{sub 60} inelastic neutron scattering selection rule: Expanded and explained

Energy Technology Data Exchange (ETDEWEB)

Poirier, Bill, E-mail: Bill.Poirier@ttu.edu [Department of Chemistry and Biochemistry, and Department of Physics, Texas Tech University, Box 41061, Lubbock, Texas 79409-1061 (United States)

2015-09-14

Recently [M. Xu et al., J. Chem. Phys. 139, 064309 (2013)], an unexpected selection rule was discovered for the title system, contradicting the previously held belief that inelastic neutron scattering (INS) is not subject to any selection rules. Moreover, the newly predicted forbidden transitions, which emerge only in the context of coupled H{sub 2} translation-rotation (TR) dynamics, have been confirmed experimentally. However, a simple physical understanding, e.g., based on group theory, has been heretofore lacking. This is provided in the present paper, in which we (1) derive the correct symmetry group for the H{sub 2}@C{sub 60} TR Hamiltonian and eigenstates; (2) complete the INS selection rule, and show that the set of forbidden transitions is actually much larger than previously believed; and (3) evaluate previous theoretical and experimental results, in light of the new findings.

MYR1-Dependent Effectors Are the Major Drivers of a Host Cell's Early Response to Toxoplasma, Including Counteracting MYR1-Independent Effects.

Science.gov (United States)

Naor, Adit; Panas, Michael W; Marino, Nicole; Coffey, Michael J; Tonkin, Christopher J; Boothroyd, John C

2018-04-03

The obligate intracellular parasite Toxoplasma gondii controls its host cell from within the parasitophorous vacuole (PV) by using a number of diverse effector proteins, a subset of which require the aspartyl protease 5 enzyme (ASP5) and/or the recently discovered MYR1 protein to cross the PV membrane. To examine the impact these effectors have in the context of the entirety of the host response to Toxoplasma , we used RNA-Seq to analyze the transcriptome expression profiles of human foreskin fibroblasts infected with wild-type RH (RH-WT), RHΔ myr1 , and RHΔ asp5 tachyzoites. Interestingly, the majority of the differentially regulated genes responding to Toxoplasma infection are MYR1 dependent. A subset of MYR1 responses were ASP5 independent, and MYR1 function did not require ASP5 cleavage, suggesting the export of some effectors requires only MYR1. Gene set enrichment analysis of MYR1-dependent host responses suggests an upregulation of E2F transcription factors and the cell cycle and a downregulation related to interferon signaling, among numerous others. Most surprisingly, "hidden" responses arising in RHΔ myr1 - but not RH-WT-infected host cells indicate counterbalancing actions of MYR1-dependent and -independent activities. The host genes and gene sets revealed here to be MYR1 dependent provide new insight into the parasite's ability to co-opt host cell functions. IMPORTANCE Toxoplasma gondii is unique in its ability to successfully invade and replicate in a broad range of host species and cells within those hosts. The complex interplay of effector proteins exported by Toxoplasma is key to its success in co-opting the host cell to create a favorable replicative niche. Here we show that a majority of the transcriptomic effects in tachyzoite-infected cells depend on the activity of a novel translocation system involving MYR1 and that the effectors delivered by this system are part of an intricate interplay of activators and suppressors. Removal of all MYR1

Impact of host cell variation on the neutralization of HIV-1 in vitro.

Science.gov (United States)

Polonis, Victoria R; Schuitemaker, Hanneke; Bunnik, Evelien M; Brown, Bruce K; Scarlatti, Gabriella

2009-09-01

In this review we present current advances in our understanding of HIV-1 neutralization assays that employ primary cell types, as compared with those that utilize cell lines and the newer, more standardized pseudovirus assays. A commentary on the challenges of standardizing in-vitro neutralization assays using primary cells is included. The data from reporter cell line neutralization assays may agree with results observed in primary cells; however, exceptions have recently been reported. Multiple variables exist in primary cell assays using peripheral blood mononuclear cells from HIV-seronegative donors; in-vitro neutralization titers can vary significantly based on the donor cells used for assay targets and for virus propagation. Thus, more research is required to achieve validated primary cell neutralization assays. HIV-vaccine-induced antibody performance in the current neutralization assays may function as a 'gatekeeper' for HIV-1 subunit vaccine advancement. Development of standardized platforms for reproducible measurement of in-vitro neutralization is therefore a high priority. Given the considerable variation in results obtained from some widely applied HIV neutralization platforms, parallel evaluation of new antibodies using different host cells for assay targets, as well as virus propagation, is recommended until immune correlates of protection are identified.

Manipulation of Host Cholesterol by Obligate Intracellular Bacteria

Directory of Open Access Journals (Sweden)

Dhritiman Samanta

2017-05-01

Full Text Available Cholesterol is a multifunctional lipid that plays important metabolic and structural roles in the eukaryotic cell. Despite having diverse lifestyles, the obligate intracellular bacterial pathogens Chlamydia, Coxiella, Anaplasma, Ehrlichia, and Rickettsia all target cholesterol during host cell colonization as a potential source of membrane, as well as a means to manipulate host cell signaling and trafficking. To promote host cell entry, these pathogens utilize cholesterol-rich microdomains known as lipid rafts, which serve as organizational and functional platforms for host signaling pathways involved in phagocytosis. Once a pathogen gains entrance to the intracellular space, it can manipulate host cholesterol trafficking pathways to access nutrient-rich vesicles or acquire membrane components for the bacteria or bacteria-containing vacuole. To acquire cholesterol, these pathogens specifically target host cholesterol metabolism, uptake, efflux, and storage. In this review, we examine the strategies obligate intracellular bacterial pathogens employ to manipulate cholesterol during host cell colonization. Understanding how obligate intracellular pathogens target and use host cholesterol provides critical insight into the host-pathogen relationship.

Survey report for fiscal 1998. Survey of the current state and tasks of research and development of technologies for effectively utilizing CO{sub 2} fixation by higher vegetation; 1998 nendo chosa hokokusho. Koto shokubutsu ni okeru nisanka tanso koteika yuko riyo gijutsu no kenkyu kaihatsu no genjo to kadai ni kansuru chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

Investigations and studies are conducted seeking for a CO2 fixation method improved by utilizing the photosynthesizing function of higher vegetation. Details of higher vegetation genes are being disclosed thanks to the rapid progress of studies making use of molecular biological techniques, and the application of the genetic mechanism to scientific and technological fields is becoming increasingly feasible. In particular, the role of the CO2 fixation enzyme RuBisCO has been elucidated almost completely. It has been learned that, in terms of photosynthesizing capability, the C{sub 4} plants (corn etc.) are 2-3 times higher than the C{sub 3} plants (rice, wheat, etc.), and 5-10 times higher than the CAM plants (cactuses etc.). Studies are also under way about the rice genome so that a photosynthesizing capability so high as that of the C{sub 4} plants may be endowed the rice plant. The metabolism and control of useful substances produced in the CO2 fixation process etc. in the higher vegetation are being investigated, and it is now expected that some day such useful substances will be produced and utilized efficiently. Researches are under way into the relationship between the green leaf that is the organ that performs photosynthesis and the organ (sink) that stores and utilizes starch and sugar is in progress, and now a new field is going to open where vegetables will be fully utilized. (NEDO)

Catalytic conversion of light alkanes-proof-of-concept stage - Phase IV. Topical report, February 1, 1994--January 31, 1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-12-31

This report details the research performed on Phase IV of the extended Cooperative Agreement. This Phase, entitled C{sub 1}-C{sub 4} Research, provides the research support which accompanies the C{sub 4} Proof-of-Concept Phase (Phase V) as the two major activities of the Cooperative Agreement during calendar 1993. It is the objective of this phase to understand the nature of the catalysts and catalytic activity of perhaloporphyrin complexes uncovered during Phases I-III in order that superior catalytic materials can be made and tested which meet commercial criteria for the oxidation of the C{sub 1}-C{sub 4} light alkane gases found in natural gas and other available hydrocarbon streams. During Phase IV, we have examined the physical and electronic structures of the very active perhaloporphyrin catalysts which we have developed, and have gained an understanding of the properties which make them active. This has led us to design and synthesize materials which are cheaper, more active, more robust and, in general superior for carrying out practical catalysis. Our early generation perhaloporphyrin catalysts, while exhibiting unprecedented catalytic activity, were far too expensive for use in converting natural gas or its C{sub 1}-C{sub 4} components.

THE HOST GALAXY PROPERTIES OF VARIABILITY SELECTED AGN IN THE PAN-STARRS1 MEDIUM DEEP SURVEY

Energy Technology Data Exchange (ETDEWEB)

Heinis, S.; Gezari, S.; Kumar, S. [Department of Astronomy, University of Maryland, College Park, MD (United States); Burgett, W. S.; Flewelling, H.; Huber, M. E.; Kaiser, N.; Wainscoat, R. J.; Waters, C. [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

2016-07-20

We study the properties of 975 active galactic nuclei (AGNs) selected by variability in the Pan-STARRS1 Medium deep Survey. Using complementary multi-wavelength data from the ultraviolet to the far-infrared, we use spectral energy distribution fitting to determine the AGN and host properties at z < 1 and compare to a well-matched control sample. We confirm the trend previously observed: that the variability amplitude decreases with AGN luminosity, but we also observe that the slope of this relation steepens with wavelength, resulting in a “redder when brighter” trend at low luminosities. Our results show that AGNs are hosted by more massive hosts than control sample galaxies, while the rest frame dust-corrected NUV r color distribution of AGN hosts is similar to control galaxies. We find a positive correlation between the AGN luminosity and star formation rate (SFR), independent of redshift. AGN hosts populate the entire range of SFRs within and outside of the Main Sequence of star-forming galaxies. Comparing the distribution of AGN hosts and control galaxies, we show that AGN hosts are less likely to be hosted by quiescent galaxies and more likely to be hosted by Main Sequence or starburst galaxies.

Resiniferatoxin modulates the Th1 immune response and protects the host during intestinal nematode infection.

Science.gov (United States)

Muñoz-Carrillo, J L; Contreras-Cordero, J F; Muñoz-López, J L; Maldonado-Tapia, C H; Muñoz-Escobedo, J J; Moreno-García, M A

2017-09-01

In the early stage of the intestinal phase of Trichinella spiralis infection, the host triggers a Th1-type immune response with the aim of eliminating the parasite. However, this response damages the host which favours the survival of the parasite. In the search for novel pharmacological strategies that inhibit the Th1 immune response and assist the host against T. spiralis infection, a recent study showed that resiniferatoxin had anti-inflammatory activity contributed to the host in T. spiralis infection. In this study, we evaluated whether RTX modulates the host immune response through the inhibition of Th1 cytokines in the intestinal phase. In addition, it was determined whether the treatment with RTX affects the infectivity of T. spiralis-L1 and the development of the T. spiralis life cycle. Our results show that RTX decreased serum levels of IL-12, INF-γ, IL-1β, TNF-α and parasite burden on muscle tissue. It was observed that T. spiralis-L1 treated with RTX decreased their infectivity affecting the development of the T. spiralis life cycle in mouse. These results demonstrate that RTX is able to inhibit the production of Th1 cytokines, contributing to the defence against T. spiralis, which places it as a potential drug modulator of the immune response. © 2017 John Wiley & Sons Ltd.

KAP1 Is a Host Restriction Factor That Promotes Human Adenovirus E1B-55K SUMO Modification

DEFF Research Database (Denmark)

Bürck, Carolin; Mund, Andreas; Berscheminski, Julia

2016-01-01

Once transported to the replication sites, HAdVs need to assure decondensation and transcriptional activation of their viral genomes to synthesize viral proteins and initiate steps to reprogram the host cell for viral replication. These early stages during adenoviral infection are poorly characte......Once transported to the replication sites, HAdVs need to assure decondensation and transcriptional activation of their viral genomes to synthesize viral proteins and initiate steps to reprogram the host cell for viral replication. These early stages during adenoviral infection are poorly...... characterized, but represent a decisive moment in establishing a productive infection. Here, we identify a novel host viral restriction factor, KAP1. This heterochromatin associated transcription factor regulates the dynamic organization of host chromatin structure via its ability to influence epigenetic marks...

Improved power efficiency of blue fluorescent organic light-emitting diode with intermixed host structure

Energy Technology Data Exchange (ETDEWEB)

Yue, Shouzhen; Zhang, Shiming; Zhang, Zhensong; Wu, Yukun; Wang, Peng; Guo, Runda; Chen, Yu; Qu, Dalong; Wu, Qingyang; Zhao, Yi, E-mail: yizhao@jlu.edu.cn; Liu, Shiyong

2013-11-15

High power efficiency (PE) p-bis(p-N,N-diphenyl-aminostyryl)benzene (DSA-ph) based fluorescent blue organic light-emitting diode (OLED) is demonstrated by utilizing intermixed host (IH) structure. The PE outperforms those devices based on single host (SH), mixed host (MH), and double emitting layers (DELs). By further optimizing the intermixed layer, peak PE of the IH device is increased up to 8.7 lm/W (1.7 times higher than conventional SH device), which is the highest value among the DSA-ph based blue device reported so far. -- Highlights: • DSA-ph based blue fluorescent OLEDs are fabricated. • The intermixed host structure is first introduced into the blue devices. • Blue device with the highest power efficiency based on DSA-ph is obtained.

The metal-enriched host of an energetic γ-ray burst at z ≈ 1.6

Science.gov (United States)

Krühler, T.; Fynbo, J. P. U.; Geier, S.; Hjorth, J.; Malesani, D.; Milvang-Jensen, B.; Levan, A. J.; Sparre, M.; Watson, D. J.; Zafar, T.

2012-10-01

Context. The star-forming nature of long γ-ray burst (GRB) host galaxies provides invaluable constraints on the progenitors of GRBs and might open a short-cut to the characteristics of typical star-forming galaxies throughout the history of the Universe. Due to the absence of near-infrared (NIR) spectroscopy, however, detailed investigations, specifically a determination of the gas-phase metallicity of gamma-ray burst hosts, was largely limited to redshifts z 1 GRB host in unprecedented detail and investigate the relation between GRB hosts and field galaxies. Methods: We availed of VLT/X-shooter optical/NIR spectroscopy to measure the metallicity, electron density, star-formation rate (SFR), and reddening of the host of GRB 080605. Specifically, we used different strong-line diagnostics to robustly measure the gas-phase metallicity within the interstellar medium (ISM) for the first time based on [N ii] at this redshift. Results: The host of the energetic (Eγ,iso ~ 2 × 1053 erg) GRB 080605 at z ~ 1.64 is a morphologically complex, vigorously star-forming galaxy with an Hα-derived SFR of 31-6+12 M⊙ yr-1. Its ISM is significantly enriched with metals. Specifically, [N ii]/Hα = 0.14 ± 0.02, which yields an oxygen abundance 12 + log (O/H) between 8.3 and 8.6 depending on the adopted strong-line calibrator. This corresponds to values in the range of 0.4 - 0.8 Z⊙. For its measured stellar mass M* = 8.0-1.6+1.3 × 109 M⊙ and SFR, this value is consistent with the fundamental metallicity relation defined by star-forming field galaxies. The absence of strong Lyα emission constrains the escape fraction of resonantly-scattered Lyα photons to fesc ≲ 0.08. Conclusions: Our observations provide a detailed picture of the conditions in the ISM of a highly star-forming galaxy with irregular morphology at z ~ 1.6. They include the first robust metallicity measurement based on [N ii] for a GRB host at z > 1 and directly illustrate that GRB hosts are not necessarily

Asymmetric fission and evaporation of C{sub 60}{sup r+} (r = 2-4) fullerene ions in ion-C{sub 60} collisions: I. Proton results

Energy Technology Data Exchange (ETDEWEB)

Rentenier, A; Bordenave-Montesquieu, A; Moretto-Capelle, P; Bordenave-Montesquieu, D [LCAR-IRSAMC, UMR 5589 Universite Paul Sabatier-CNRS, 118 rte de Narbonne, 31062 Toulouse Cedex (France)

2004-06-28

A quantitative description of the asymmetric fission (AF) of C{sub 60}{sup r+} fullerene ions (r = 2-4), using a multistop coincidence technique between both fragment ions, is presented. Charged light fragment (LF) and heavy fragment (HF) size distributions are discussed together with the corresponding averaged sizes. Complete AF distributions are reported for the first time for C{sub 60}{sup 2+} ions. Simple dependences of the more probable channels and averaged fragment sizes on the partner size are found and discussed. The LF ones are not very sensitive to the parent fullerene ion charge r and vary linearly with the HF size at least for the largest ones. On the other hand the HF ones present an oscillating dependence against the LF size, the odd-numbered LFs being correlated to a smaller HF size, and depend on r. In the comparison of branching ratios between AF and the competing pure neutral evaporation channel, some emphasis is given to the behaviour of the unimolecular processes with r which are compared with the evolution of the activation energies and fission barriers. From a close examination of the individual HF distributions the production mechanisms of odd-n fragments are discussed, and the most probable dissociation channels of even-numbered C{sub n}{sup +} excited carbon clusters identified. Finally, an analysis of the neutral channels is also presented for the first time, the total neutral mass N (in carbon units) being deduced from the mass conservation law. Surprising similarities between the charged LF- and N-distributions are found. AF processes are also identified where light neutrals and ions play a symmetrical role. These findings lead us to suggest that a concerted emission of ions and heavy neutrals is probably a fission mechanism to be considered to understand the AF process of the C{sub 60} molecule in addition to the often assumed multistep fragmentation cascade scheme.

SPOC1-mediated antiviral host cell response is antagonized early in human adenovirus type 5 infection

DEFF Research Database (Denmark)

Schreiner, Sabrina; Kinkley, Sarah; Bürck, Carolin

2013-01-01

, and playing a role in DNA damage response. SPOC1 co-localized with viral replication centers in the host cell nucleus, interacted with Ad DNA, and repressed viral gene expression at the transcriptional level. We discovered that this SPOC1-mediated restriction imposed upon Ad growth is relieved by its...... viruses (HSV-1, HSV-2, HIV-1, and HCV) also depleted SPOC1 in infected cells. Our findings provide a general model for how pathogenic human viruses antagonize intrinsic SPOC1-mediated antiviral responses in their host cells. A better understanding of viral entry and early restrictive functions in host...

Cooperative use of cytochrome cd{sub 1} nitrite reductase and its redox partner cytochrome c{sub 552} to improve the selectivity of nitrite biosensing

Energy Technology Data Exchange (ETDEWEB)

Serra, A.S.; Jorge, S.R.; Silveira, C.M.; Moura, J.J.G. [REQUIMTE - Dept. de Quimica, CQFB, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Jubete, E.; Ochoteco, E.; Cabanero, G.; Grande, H. [CIDETEC - Centro de Tecnologias Electroquimicas, Parque Tecnologico de San Sebastian, Po Miramon, 196, 20009 Donostia - San Sebastian (Spain); Almeida, M.G., E-mail: mga@dq.fct.unl.pt [REQUIMTE - Dept. de Quimica, CQFB, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Escola Superior de Saude Egas Moniz, Monte de Caparica, 2829-511 Caparica (Portugal)

2011-05-05

In this work, a novel enzymatic biosensor for determination of nitrites constructed on an electrochemical transducing platform is proposed. The sensor is based on cytochrome-cd{sub 1} (cyt-cd{sub 1}) nitrite reductase from Marinobacter hydrocarbonoclasticus strain 617 as biological recognition element, and its putative physiological redox partner cytochrome-c{sub 552} (cyt-c{sub 552}), as electron mediator. The proteins were co-immobilized using a photopolymerizable polyvinyl alcohol (PVA) derivative, onto carbon paste screen printed electrodes (CPSPEs); the optimal modification conditions were 100 {mu}M cyt-cd{sub 1}/100 {mu}M cyt-c{sub 552} and 50% PVA, after a 48 h polymerization time. Electrochemical characterization of the mediator was carried out by cyclic voltammetry. The one-electron exchange between cyt-c{sub 552} and the working electrode is a quasi-reversible process, without mass transport limitations. The formal potential of the mediator is 254 {+-} 2 mV vs NHE and the intermolecular electron transfer rate constant between cytochromes c{sub 552} and cd{sub 1} is 9.9 x 10{sup 3} M{sup -1} s{sup -1}. The analytical parameters of the biosensor response to nitrite as assessed by amperometric measurements were: linear range from 10 to 200 {mu}M; detection and quantification limits of 7 and 24 {mu}M, respectively; sensitivity of 2.49 {+-} 0.08 A mol{sup -1} cm{sup 2} {mu}M{sup -1}. Catalytic profiles in the presence of possible interfering species were also investigated. The interference from competitive enzymatic reduction of dissolved oxygen could be overcome by tuning the cyclic voltammograms for faster sweep rates.

Sulfolobus tengchongensis Spindle-Shaped Virus STSV1: Virus-Host Interactions and Genomic Features

DEFF Research Database (Denmark)

Xiang, X.; Chen, L.; Huang, X

2005-01-01

of variable length (68 nm on average) at one end and is the largest of the known spindle-shaped viruses. After infecting its host, the virus multiplied rapidly to high titers (>1010 PFU/ml). Replication of the virus retarded host growth but did not cause lysis of the host cells. STSV1 did not integrate...

Micro-autoradiographic studies on host-parasite interactions. Pt. 1

International Nuclear Information System (INIS)

Mendgen, K.; Heitefuss, R.

1975-01-01

Tritium labeled uredospores of Uromyces phaseoli were produced be feeding the host, Phaseolus vulgaris, with 2 H-orotic acid. These spores were allowed to germinate on and to penetrate into a bean leaf. 24 hrs after inoculation, the bean rust had formed the first haustorium. All fungal structures, including the fungus walls, were heavily labeled. No label could be detected in the cells that had come into contact with the hyphae. In the infected host cell, the haustorium was labeled heavily, but the sheath around the haustorium and the host cell remained free of label. These results indicate that no detectable amounts of label leach from the bean rust into the host at this stage of infection although it is known that the rust takes up many metabolites. Since the sheath remains free of label and all fungal structures are evenly labeled, it is concluded that the sheath is formed by the host. (orig.) [de

Electronic structure of low work function electrodes modified by C{sub 16}H{sub 33}SH

Energy Technology Data Exchange (ETDEWEB)

Lee, Hyunbok [Department of Polymer Science and Engineering, University of Massachusetts, Amherst, MA, 01003 (United States); Cho, Sang Wan, E-mail: dio8027@yonsei.ac.kr [Department of Physics, Yonsei University, 1 Yonseidae-gil, Wonju-si, Gangwon-do, 220-710 (Korea, Republic of); Park, Sang Han; Cho, Mann-Ho; Yi, Yeonjin [Institute of Physics and Applied Physics, Yonsei University, 50 Yonsei-ro, Seodaemoon-Gu, Seoul, 120-749 (Korea, Republic of)

2014-10-15

Highlights: • The electronic structure of pentacene/C{sub 16}H{sub 33}SH/Au is investigated. • The work function of Au is significantly decreased with C{sub 16}H{sub 33}SH treatment. • The reduced work function is attributed to its permanent dipole moment. - Abstract: Organic and printed electronics technologies require electrodes with low work functions to facilitate the transport of electrons in and out of various optoelectronic devices. We show that the surface modifier of 1-hexadecanethiol reduces the work function of conductors using in situ ultraviolet photoemission spectroscopy, and we combine experimental and theoretical methods to investigate the origin of the work function changes. The interfacial electronic structures of pentacene/1-hexadecanethiol/Au were investigated via in situ ultraviolet photoemission spectroscopy and X-ray photoemission spectroscopy in order to understand the change in the carrier injection barrier and chemical reactions upon surface modification. Theoretical calculations using density functional theory were also performed to understand the charge distribution of 1-hexadecanethiol, which affects the reduction of the work function. The 1-hexadecanethiol surface modifier is processed in air from solution, providing an appealing alternative to chemically-reactive low-work-function metals.

HostPhinder: A Phage Host Prediction Tool

DEFF Research Database (Denmark)

Villarroel, Julia; Kleinheinz, Kortine Annina; Jurtz, Vanessa Isabell

2016-01-01

The current dramatic increase of antibiotic resistant bacteria has revitalised the interest in bacteriophages as alternative antibacterial treatment. Meanwhile, the development of bioinformatics methods for analysing genomic data places high-throughput approaches for phage characterization within...... bacterial hosts. HostPhinder is available as an interactive web service [1] and as a stand alone download from the Docker registry [2]....

Establisment of biflavenoids as synthons for higher oligomers: rearrangements of a (4,8)-biflavenoid as model for the phlobaphenenereaction. Daarstelling van biflavanoiede as sintone vir hoer oligomere: omskakelings van 'n (4,8)-biflavanoied as model vir die flobafeenreaksie

Energy Technology Data Exchange (ETDEWEB)

Botes, A L

1983-11-01

The typical tetraflavenoid from the core wood Acacia mearnsii(wattle) is composed of a (-)-bifisetinidol- and (-)-fisetinidol unit coupled to the nucleophilic A-ring (C/sub 8/ or C/sub 6/) of a (+)-catechyn unit. This study is aimed at the development of methods for yielding of (4,6)-type biflavenoids for the utilization as synthons for oligomer tannins and comprise primary the following two approaches: The direct biomimetic synthesis during which the C/sub 4/ carbenium ion from a flavan-3,4-diol react with a 4-8 mol excess of the nucleophilic flavan-3-ol, was on a 1:1 mol base re-investigated. The second approach comprises C/sub 3/-2,4-dihydroxybenzylation of (+)-catechyn, followed by interflavenoid coupling at C/sub 6/ and subsequently selective removal of the C/sub 8/-substituent to supply (4,6)-biflavenoids, C/sub 8/ of (+)-catechyn is indeed in 70% yield with the 2,4-dihydroxybenzylation group protected whereafter regiospesific (4,6)-interflavenoid coupling with (+)-mollisacacidin was likewise successfully executed. The relative bond strenghts of C/sub 6/- and C/sub 8/-substituents on the (+)-catechyn unit are qualitatively determined by acid hydrolysis of the model compounds 8-(2,4-dihydroxybenzyl)-(+)-catechyn; 6-((-)-fisetinidol)-(+)-catechyn; 8((-)-fisetinidol)-(+)-catechyn; (+)-catechyn-(4..cap alpha.. ->6)-(+)-catechyn and (+)-catechyn-(4..cap alpha.. -> 8)-(+)-catechyn. The /sup 1/H nmr spectrum of the crystalline (H/sub 2/O)-free phenolic (4,8)-3,4-cis-biflavenoid made the determination of natural biflavenoid conformations possible for the first time.

Cytotoxic Vibrio T3SS1 Rewires Host Gene Expression to Subvert Cell Death Signaling and Activate Cell Survival Networks

Science.gov (United States)

De Nisco, Nicole J.; Kanchwala, Mohammed; Li, Peng; Fernandez, Jessie; Xing, Chao; Orth, Kim

2017-01-01

Bacterial effectors are potent manipulators of host signaling pathways. The marine bacterium Vibrio parahaemolyticus (V. para), delivers effectors into host cells through two type three secretion systems (T3SS). The ubiquitous T3SS1 is vital for V. para survival in the environment, whereas T3SS2 causes acute gastroenteritis in human hosts. Although the natural host is undefined, T3SS1 effectors attack highly conserved cellular processes and pathways to orchestrate non-apoptotic cell death. Much is known about how T3SS1 effectors function in isolation, but we wanted to understand how their concerted action globally affects host cell signaling. To assess the host response to T3SS1, we compared gene expression changes over time in primary fibroblasts infected with V. para that have a functional T3SS1 (T3SS1+) to those in cells infected with V. para lacking T3SS1 (T3SS1−). Overall, the host transcriptional response to both T3SS1+ and T3SS1− V. para was rapid, robust, and temporally dynamic. T3SS1 re-wired host gene expression by specifically altering the expression of 398 genes. Although T3SS1 effectors target host cells at the posttranslational level to cause cytotoxicity, network analysis indicated that V. para T3SS1 also precipitates a host transcriptional response that initially activates cell survival and represses cell death networks. The increased expression of several key pro-survival transcripts mediated by T3SS1 was dependent on a host signaling pathway that is silenced later in infection by the posttranslational action of T3SS1. Taken together, our analysis reveals a complex interplay between roles of T3SS1 as both a transcriptional and posttranslational manipulator of host cell signaling. PMID:28512145

EPA Region 1 - Map Layers for Valley ID Tool (Hosted Feature Service)

Data.gov (United States)

U.S. Environmental Protection Agency — The Valley Service Feature Layer hosts spatial data for EPA Region 1's Valley Identification Tool. These layers contain attribute information added by EPA R1 GIS...

Environmental Drivers of Seasonal Patterns of Host Utilization by Culiseta melanura (Diptera: Culicidae) in Florida.

Science.gov (United States)

Blosser, Erik M; Lord, Cynthia C; Stenn, Tanise; Acevedo, Carolina; Hassan, Hassan K; Reeves, Lawrence E; Unnasch, Thomas R; Burkett-Cadena, Nathan D

2017-09-01

Field studies were carried out in four Florida counties to investigate winter and spring ecology of host use by Culiseta melanura (Coquillet), the primary vector of eastern equine encephalomyelitis virus (EEEV) in North America. Bloodmeal analysis by PCR was used to identify 233 host bloodmeals, which mainly originated from birds (78.5%) and reptiles (17.2%), primarily Anolis spp. lizards. Across counties, the percentage of bloodmeals from reptiles (7-37% depending upon county) increased with increasing day length and temperature in the spring. Multiple logistic regression revealed that differences in reptile host use across collection sites were largely explained by differences in average day length and temperature on the day of collection, and is probably owing to environment-driven behavioral patterns of ectothermic animals. Although past studies have demonstrated reptile biting by epizootic vectors of EEEV, including Culex (Melanoconion) spp., this is the first study to demonstrate widespread and common feeding upon ectothermic hosts by Cs. melanura. This work suggests that reptiles, particularly anole lizards, play a role in the ecology of EEEV in Florida either as amplifying hosts or as noncompetent hosts which dilute vector feedings thereby suppressing transmission. Detailed laboratory studies investigating impacts of environmental variables (temperature and photoperiod) on EEEV competence of anoles are needed to assess whether these animals support virus amplification. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

MYR1-Dependent Effectors Are the Major Drivers of a Host Cell’s Early Response to Toxoplasma, Including Counteracting MYR1-Independent Effects

Directory of Open Access Journals (Sweden)

Adit Naor

2018-04-01

Full Text Available The obligate intracellular parasite Toxoplasma gondii controls its host cell from within the parasitophorous vacuole (PV by using a number of diverse effector proteins, a subset of which require the aspartyl protease 5 enzyme (ASP5 and/or the recently discovered MYR1 protein to cross the PV membrane. To examine the impact these effectors have in the context of the entirety of the host response to Toxoplasma, we used RNA-Seq to analyze the transcriptome expression profiles of human foreskin fibroblasts infected with wild-type RH (RH-WT, RHΔmyr1, and RHΔasp5 tachyzoites. Interestingly, the majority of the differentially regulated genes responding to Toxoplasma infection are MYR1 dependent. A subset of MYR1 responses were ASP5 independent, and MYR1 function did not require ASP5 cleavage, suggesting the export of some effectors requires only MYR1. Gene set enrichment analysis of MYR1-dependent host responses suggests an upregulation of E2F transcription factors and the cell cycle and a downregulation related to interferon signaling, among numerous others. Most surprisingly, “hidden” responses arising in RHΔmyr1- but not RH-WT-infected host cells indicate counterbalancing actions of MYR1-dependent and -independent activities. The host genes and gene sets revealed here to be MYR1 dependent provide new insight into the parasite’s ability to co-opt host cell functions.

Herpesvirus papio 2 encodes a virion host shutoff function.

Science.gov (United States)

Bigger, John E; Martin, David W

2002-12-05

Infection of baboons with herpesvirus papio 2 (HVP-2) produces a disease that is similar to human infection with herpes simplex viruses (HSV). Molecular characterization of HVP-2 has demonstrated that the virion contains a factor which rapidly shuts off host cell protein synthesis after infection. Reduction of host cell protein synthesis occurs in parallel with the degradation of mRNA species. A homolog of the HSV virion host shutoff (vhs) gene was identified by Southern and DNA sequence analysis. The sequence of the HVP-2 vhs gene homolog had greater than 70% identity with the vhs genes of HSV 1 and 2. Disruption of the HVP-2 vhs open reading frame diminished the ability of the virus to shut off protein synthesis and degrade cellular mRNA, indicating that this gene was responsible for the vhs activity. The HVP-2 model system provides the opportunity to study the biological role of vhs in the context of a natural primate host. Further development of this system will provide a platform for proof-of-concept studies that will test the efficacy of vaccines that utilize vhs-deficient viruses.

Drug Discovery of Host CLK1 Inhibitors for Influenza Treatment

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Mian Zu

2015-11-01

Full Text Available The rapid evolution of influenza virus makes antiviral drugs less effective, which is considered to be a major bottleneck in antiviral therapy. The key proteins in the host cells, which are related with the replication cycle of influenza virus, are regarded as potential drug targets due to their distinct advantage of lack of evolution and drug resistance. Cdc2-like kinase 1 (CLK1 in the host cells is responsible for alternative splicing of the M2 gene of influenza virus during influenza infection and replication. In this study, we carried out baculovirus-mediated expression and purification of CLK1 and established a reliable screening assay for CLK1 inhibitors. After a virtual screening of CLK1 inhibitors was performed, the activities of the selected compounds were evaluated. Finally, several compounds with strong inhibitory activity against CLK1 were discovered and their in vitro anti-influenza virus activities were validated using a cytopathic effect (CPE reduction assay. The assay results showed that clypearin, corilagin, and pinosylvine were the most potential anti-influenza virus compounds as CLK1 inhibitors among the compounds tested. These findings will provide important information for new drug design and development in influenza treatment, and CLK1 may be a potent drug target for anti-influenza drug screening and discovery.

Photocatalytic degradation of hexadecyl trimethyl ammonium chloride C/sub 19/H/sub 42/NCl

International Nuclear Information System (INIS)

Hassan, M.U.; Anwar, J.; Saif, M.J.

2008-01-01

Surfactants in the environment are a prerequisite for the sustainable development of human health and ecosystems. Surfactants are important in daily life in households as well as in industrial cleansing processes. It is important to have a detailed knowledge about their lifetime in the environment, their biodegradability in wastewater treatment plants and in natural waters, and their ecotoxicity. Most of the issues on environmental acceptability focus on the effects on the environment associated with the use and disposal of these surfactants. These effects are taken into account by a risk assessment. The first step in a risk assessment is an estimate of the concentrations of surf act ants in the environmental compartment of interest, such as wastewater treatment plant effluents, surface waters, sediments, and soils. This estimate is generated either by actual measurement or by prediction via modelling. The measured or predicted concentrations are then compared to the concentrations of surfactant known to be toxic to organisms living in these environmental compartments. There are many situations where industry is producing both heavy metals ions and organic pollutants, Successful treatment of effluents of this type to achieve legislative compliance will depend on whether the heavy metals effect the process of degradation of the organic species and whether the presence of organic molecules hinder the process of removal of heavy metals. Degradation of cationic surfactant was studied with a photolytic cell system. Compressed air was used as oxidant and the temperature was maintained at 25-30 degree C. Effect of UV source, hydrogen peroxide (H/sub 2/O/sub 2/) and titanium (TiO/sub 2/) on Hexadecyl trimethyl ammonium Chloride C/sub 19/H/sub 42/NCl were recorded. HPLC and IR were used to analyse to study the rate of degradation of C/sub 19/H/sub 42/NCl. (author)

Interleukin-1 signaling is essential for host defense during murine pulmonary tuberculosis

NARCIS (Netherlands)

Juffermans, N. P.; Florquin, S.; Camoglio, L.; Verbon, A.; Kolk, A. H.; Speelman, P.; van Deventer, S. J.; van der Poll, T.

2000-01-01

Interleukin (IL)-1 signaling is required for the containment of infections with intracellular microorganisms, such as Listeria monocytogenes and Leishmania major. To determine the role of IL-1 in the host response to tuberculosis, we infected IL-1 type I receptor-deficient (IL-1R(-/-)) mice, in

Host specialization and phylogenetic diversity of Corynespora cassiicola.

Science.gov (United States)

Dixon, L J; Schlub, R L; Pernezny, K; Datnoff, L E

2009-09-01

The fungus Corynespora cassiicola is primarily found in the tropics and subtropics, and is widely diverse in substrate utilization and host association. Isolate characterization within C. cassiicola was undertaken to investigate how genetic diversity correlates with host specificity, growth rate, and geographic distribution. C. cassiicola isolates were collected from 68 different plant species in American Samoa, Brazil, Malaysia, and Micronesia, and Florida, Mississippi, and Tennessee within the United States. Phylogenetic analyses using four loci were performed with 143 Corynespora spp. isolates, including outgroup taxa obtained from culture collections: C. citricola, C. melongenae, C. olivacea, C. proliferata, C. sesamum, and C. smithii. Phylogenetic trees were congruent from the ribosomal DNA internal transcribed spacer region, two random hypervariable loci (caa5 and ga4), and the actin-encoding locus act1, indicating a lack of recombination within the species and asexual propagation. Fifty isolates were tested for pathogenicity on eight known C. cassiicola crop hosts: basil, bean, cowpea, cucumber, papaya, soybean, sweet potato, and tomato. Pathogenicity profiles ranged from one to four hosts, with cucumber appearing in 14 of the 16 profiles. Bootstrap analyses and Bayesian posterior probability values identified six statistically significant phylogenetic lineages. The six phylogenetic lineages correlated with host of origin, pathogenicity, and growth rate but not with geographic location. Common fungal genotypes were widely distributed geographically, indicating long-distance and global dispersal of clonal lineages. This research reveals an abundance of previously unrecognized genetic diversity within the species and provides evidence for host specialization on papaya.

Crystal structure of 2-(thiophen-2-yl)-1-(5-thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl) ethenyl]benzamide: N,N-dimethylformamide (1 : 1)

Energy Technology Data Exchange (ETDEWEB)

Sharma, P. [University of Jammu, X-ray Crystallography Laboratory, Department of Physics (India); Subbulakshmi, K. N.; Narayana, B. [Mangalore University, Department of Chemistry (India); Sarojini, B. K. [Mangalore University, Industrial Chemistry Division, Department of Studies in Chemistry (India); Kant, R., E-mail: rkant.ju@gmail.com [University of Jammu, X-ray Crystallography Laboratory, Department of Physics (India)

2016-03-15

The title compound, 2-(thiophen-2-yl)-1-(5-thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)ethenyl] benzamide:N,N-dimethylformamide (1: 1), (C{sub 15}H{sub 11}N{sub 3}O{sub 2}S{sub 2} · C{sub 3}H{sub 7}NO), was synthesized, and its structure was established by spectral analysis and X-ray diffraction studies. The compound crystallizes in the monoclinic space group P2{sub 1}/n with a = 10.8714(7), b = 9.0497(5), c = 19.8347(13) Å, β = 91.093(5)°, Z = 4. The crystal structure is stabilized by N–H···S, C–H···O and N–H···O hydrogen bonds. The π···π interactions are also observed between the rings.

A Global Interactome Map of the Dengue Virus NS1 Identifies Virus Restriction and Dependency Host Factors

Directory of Open Access Journals (Sweden)

Mohamed Lamine Hafirassou

2017-12-01

Full Text Available Dengue virus (DENV infections cause the most prevalent mosquito-borne viral disease worldwide, for which no therapies are available. DENV encodes seven non-structural (NS proteins that co-assemble and recruit poorly characterized host factors to form the DENV replication complex essential for viral infection. Here, we provide a global proteomic analysis of the human host factors that interact with the DENV NS1 protein. Combined with a functional RNAi screen, this study reveals a comprehensive network of host cellular processes involved in DENV infection and identifies DENV host restriction and dependency factors. We highlight an important role of RACK1 and the chaperonin TRiC (CCT and oligosaccharyltransferase (OST complexes during DENV replication. We further show that the OST complex mediates NS1 and NS4B glycosylation, and pharmacological inhibition of its N-glycosylation function strongly impairs DENV infection. In conclusion, our study provides a global interactome of the DENV NS1 and identifies host factors targetable for antiviral therapies.

Reaction of the C2H radical with 1-butyne (C4H6): Low Temperature Kinetics and Isomer-Specific Product Detection

Energy Technology Data Exchange (ETDEWEB)

Soorkia, Satchin; Trevitt, Adam J.; Selby, Talitha M.; Osborn, David L.; Taatjes, Craig A.; Wilson, Kevin R.; Leone, Stephen R.

2009-12-22

The rate coefficient for the reaction of the ethynyl radical (C{sub 2}H) with 1-butyne (H-C{triple_bond}C-CH{sub 2}-CH{sub 3}) is measured in a pulsed Laval nozzle apparatus. Ethynyl radicals are formed by laser photolysis of acetylene (C{sub 2}H{sub 2}) at 193 nm and detected via chemiluminescence (C{sub 2}H + O{sub 2} {yields} CH (A{sup 2}{Delta}) + CO{sub 2}). The rate coefficients are measured over the temperature range of 74-295 K. The C{sub 2}H + 1-butyne reaction exhibits no barrier and occurs with rate constants close to the collision limit. The temperature dependent rate coefficients can be fit within experimental uncertainties by the expression k = (2.4 {+-} 0.5) x 10{sup -10} (T/295 K)-(0.04 {+-} 0.03) cm{sup 3} molecule{sup -1}s{sup -1}. Reaction products are detected at room temperature (295 K) and 533 Pa using a Multiplexed Photoionization Mass Spectrometer (MPIMS) coupled to the tunable VUV synchrotron radiation from the Advanced Light Source at the Lawrence Berkeley National Laboratory. Two product channels are identified for this reaction: m/z = 64 (C{sub 5}H{sub 4}) and m/z = 78 (C{sub 6}H{sub 6}) corresponding to the CH{sub 3}- and H-loss channels, respectively. Photoionization efficiency (PIE) curves are used to analyze the isomeric composition of both product channels. The C{sub 5}H{sub 4} products are found to be exclusively linear isomers composed of ethynylallene and methyldiacetylene in a 4:1 ratio. In contrast, the C{sub 6}H{sub 6} product channel includes two cyclic isomers, fulvene 18({+-}5)% and 3,4-dimethylenecyclobut-1-ene 32({+-}8)%, as well as three linear isomers, 2-ethynyl-1,3-butadiene 8({+-}5)%, 3,4-hexadiene-1-yne 28({+-}8)% and 1,3-hexadiyne 14({+-}5)%. Within experimental uncertainties, we do not see appreciable amounts of benzene and an upper limit of 10% is estimated. Diacetylene (C{sub 4}H{sub 2}) formation via the C{sub 2}H{sub 5}-loss channel is also thermodynamically possible but cannot be observed due to experimental

A empiric expression to interpret the approximation of {lambda} cI phages to E. coli C{sub 6}00 bacteria; Determinacion experimental de la cinetica de laproximacion del fago /{lambda}cl a la bacteria E. coli C{sub 6}00 Expression empirica interpretativa del proceso

Energy Technology Data Exchange (ETDEWEB)

Garces, F; Vidania, R de

1984-07-01

In general the process of adsorption of phages to bacteria is considered in the bibliography as an statistical process. In this work we use an empiric expression which allows to interpret the approximation of {lambda}cI pages to E. coli C{sub 6}00 bacteria. This expression introduces some changes respect to a pure statistical description of the approximation process. (Author) 26 refs.

VUV and soft x-ray ionization of a plant volatile: Vanillin (C{sub 8}H{sub 8}O{sub 3})

Energy Technology Data Exchange (ETDEWEB)

Betancourt, A. Moreno; Moura, C. E. V. de; Rocha, A. B.; Souza, G. G. B. de, E-mail: rafael.bernini@ifrj.edu.br, E-mail: gerson@iq.ufrj.br [Instituto de Química, Universidade Federal do Rio de Janeiro (UFRJ) 21949-900 Rio de Janeiro–RJ (Brazil); Coutinho, L. H. [Instituto de Física, Universidade Federal do Rio de Janeiro (UFRJ) 21941-972 Rio de Janeiro–RJ (Brazil); Bernini, R. B., E-mail: rafael.bernini@ifrj.edu.br, E-mail: gerson@iq.ufrj.br [Instituto Federal de Ciência e Tecnologia do Rio de Janeiro (IFRJ), 25050-100 Duque de Caxias–RJ (Brazil)

2016-03-21

Plant volatiles are emitted by plants in response to several forms of stress, including interaction with energetic photons. In the present work, we discuss the interaction of extreme UV and soft X-ray photons with a plant volatile, vanillin. The single and double (multiple) ionization of the vanillin molecule have been studied for the first time using time-of-flight mass spectrometry and VUV and soft X-ray photons (synchrotron radiation, at 12.0 eV, 21.2 eV, 130 eV, 310 eV, 531 eV, and 550 eV). At 12.0 and 21.2 eV, only singly charged species are observed and the parent ion, C{sub 8}H{sub 8}O{sub 3}{sup +}, is the dominant species. Energy differences for some selected fragments were calculated theoretically in this energy region. At 130 eV, direct double and triple ionization of the valence electrons may occur. The fragmentation increases and CHO{sup +} becomes one of the main cations in the mass spectrum. The molecular ion is still the dominant species, but other fragments, such as C{sub 6}H{sub 5}O{sup +}, begin to present similar intensities. At 310 eV, C 1s electrons may be ionized and Auger processes give rise to dissociative doubly ionized cations. Ionization around the O 1s edge has been studied both at the 531 eV resonance and above the ionization edge. Resonant and normal Auger processes play a significant role in each case and a large fragmentation of the molecule is observed at both photon energies, with intense fragments such as CHO{sup +} and CH{sub 3}{sup +} being clearly observed. A near edge X-ray absorption fine structure spectrum of the vanillin molecule was obtained around the O 1s ionization threshold. In addition, the fragmentation of vanillin has also been studied using a fast beam of electrons (800 eV), for the sake of comparison.

Host heme oxygenase-1: Friend or foe in tackling pathogens?

Science.gov (United States)

Singh, Nisha; Ahmad, Zeeshan; Baid, Navin; Kumar, Ashwani

2018-05-14

Infectious diseases are a major challenge in management of human health worldwide. Recent literature suggests that host immune system could be modulated to ameliorate the pathogenesis of infectious disease. Heme oxygenase (HMOX1) is a key regulator of cellular signaling and it could be modulated using pharmacological reagents. HMOX1 is a cytoprotective enzyme that degrades heme to generate carbon monoxide (CO), biliverdin, and molecular iron. CO and biliverdin (or bilirubin derived from it) can restrict the growth of a few pathogens. Both of these also induce antioxidant pathways and anti-inflammatory pathways. On the other hand, molecular iron can induce proinflammatory pathway besides making the cellular environment oxidative in nature. Since microbial infections often induce oxidative stress in host cells/tissues, role of HMOX1 has been analyzed in the pathogenesis of number of infections. In this review, we have described the role of HMOX1 in pathogenesis of bacterial infections caused by Mycobacterium species, Salmonella and in microbial sepsis. We have also provided a succinct overview of the role of HMOX1 in parasitic infections such as malaria and leishmaniasis. In the end, we have also elaborated the role of HMOX1 in viral infections such as AIDS, hepatitis, dengue, and influenza. © 2018 IUBMB Life, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

Nuclear imprisonment of host cellular mRNA by nsp1β protein of porcine reproductive and respiratory syndrome virus

International Nuclear Information System (INIS)

Han, Mingyuan; Ke, Hanzhong; Zhang, Qingzhan; Yoo, Dongwan

2017-01-01

Positive-strand RNA genomes function as mRNA for viral protein synthesis which is fully reliant on host cell translation machinery. Competing with cellular protein translation apparatus needs to ensure the production of viral proteins, but this also stifles host innate defense. In the present study, we showed that porcine reproductive and respiratory syndrome virus (PRRSV), whose replication takes place in the cytoplasm, imprisoned host cell mRNA in the nucleus, which suggests a novel mechanism to enhance translation of PRRSV genome. PRRSV nonstructural protein (nsp) 1β was identified as the nuclear protein playing the role for host mRNA nuclear retention and subversion of host protein synthesis. A SAP (SAF-A/B, Acinus, and PIAS) motif was identified in nsp1β with the consensus sequence of 126 -LQxxLxxxGL- 135 . In situ hybridization unveiled that SAP mutants were unable to cause nuclear retention of host cell mRNAs and did not suppress host protein synthesis. In addition, these SAP mutants reverted PRRSV-nsp1β-mediated suppression of interferon (IFN) production, IFN signaling, and TNF-α production pathway. Using reverse genetics, a series of SAP mutant PRRS viruses, vK124A, vL126A, vG134A, and vL135A were generated. No mRNA nuclear retention was observed during vL126A and vL135A infections. Importantly, vL126A and vL135A did not suppress IFN production. For other arteriviruses, mRNA nuclear accumulation was also observed for LDV-nsp1β and SHFV-nsp1β. EAV-nsp1 was exceptional and did not block the host mRNA nuclear export. - Highlights: •PRRS virus blocks host mRNA nuclear export to the cytoplasm. •PRRSV nsp1β is the viral protein responsible for host mRNA nuclear retention. •SAP domain in nsp1β is essential for host mRNA nuclear retention and type I interferon suppression. •Mutation in the SAP domain of nsp1β causes the loss of function. •Host mRNA nuclear retention by nsp1β is common in the family Arteriviridae, except equine arteritis virus.

Nuclear imprisonment of host cellular mRNA by nsp1β protein of porcine reproductive and respiratory syndrome virus

Energy Technology Data Exchange (ETDEWEB)

Han, Mingyuan, E-mail: hanming@umich.edu; Ke, Hanzhong; Zhang, Qingzhan; Yoo, Dongwan, E-mail: dyoo@illinois.edu

2017-05-15

Positive-strand RNA genomes function as mRNA for viral protein synthesis which is fully reliant on host cell translation machinery. Competing with cellular protein translation apparatus needs to ensure the production of viral proteins, but this also stifles host innate defense. In the present study, we showed that porcine reproductive and respiratory syndrome virus (PRRSV), whose replication takes place in the cytoplasm, imprisoned host cell mRNA in the nucleus, which suggests a novel mechanism to enhance translation of PRRSV genome. PRRSV nonstructural protein (nsp) 1β was identified as the nuclear protein playing the role for host mRNA nuclear retention and subversion of host protein synthesis. A SAP (SAF-A/B, Acinus, and PIAS) motif was identified in nsp1β with the consensus sequence of {sub 126}-LQxxLxxxGL-{sub 135}. In situ hybridization unveiled that SAP mutants were unable to cause nuclear retention of host cell mRNAs and did not suppress host protein synthesis. In addition, these SAP mutants reverted PRRSV-nsp1β-mediated suppression of interferon (IFN) production, IFN signaling, and TNF-α production pathway. Using reverse genetics, a series of SAP mutant PRRS viruses, vK124A, vL126A, vG134A, and vL135A were generated. No mRNA nuclear retention was observed during vL126A and vL135A infections. Importantly, vL126A and vL135A did not suppress IFN production. For other arteriviruses, mRNA nuclear accumulation was also observed for LDV-nsp1β and SHFV-nsp1β. EAV-nsp1 was exceptional and did not block the host mRNA nuclear export. - Highlights: •PRRS virus blocks host mRNA nuclear export to the cytoplasm. •PRRSV nsp1β is the viral protein responsible for host mRNA nuclear retention. •SAP domain in nsp1β is essential for host mRNA nuclear retention and type I interferon suppression. •Mutation in the SAP domain of nsp1β causes the loss of function. •Host mRNA nuclear retention by nsp1β is common in the family Arteriviridae, except equine

Where in the Cell Are You? Probing HIV-1 Host Interactions through Advanced Imaging Techniques

Directory of Open Access Journals (Sweden)

Brennan S. Dirk

2016-10-01

Full Text Available Viruses must continuously evolve to hijack the host cell machinery in order to successfully replicate and orchestrate key interactions that support their persistence. The type-1 human immunodeficiency virus (HIV-1 is a prime example of viral persistence within the host, having plagued the human population for decades. In recent years, advances in cellular imaging and molecular biology have aided the elucidation of key steps mediating the HIV-1 lifecycle and viral pathogenesis. Super-resolution imaging techniques such as stimulated emission depletion (STED and photoactivation and localization microscopy (PALM have been instrumental in studying viral assembly and release through both cell–cell transmission and cell–free viral transmission. Moreover, powerful methods such as Forster resonance energy transfer (FRET and bimolecular fluorescence complementation (BiFC have shed light on the protein-protein interactions HIV-1 engages within the host to hijack the cellular machinery. Specific advancements in live cell imaging in combination with the use of multicolor viral particles have become indispensable to unravelling the dynamic nature of these virus-host interactions. In the current review, we outline novel imaging methods that have been used to study the HIV-1 lifecycle and highlight advancements in the cell culture models developed to enhance our understanding of the HIV-1 lifecycle.

Contrasting feature in the repopulation of host-type T cells in the spleens of F1----P and P----F1 radiation bone marrow chimeras

International Nuclear Information System (INIS)

Hirokawa, K.; Sado, T.; Kubo, S.; Kamisaku, H.; Utsuyama, M.

1986-01-01

The regeneration and persistence of host- and donor-derived T cells were examined in the thymus as well as the spleen of mouse radiation bone marrow chimeras of two semiallogeneic combinations (F1----P, P----F1) with different Thy-1 markers on T cells of donor and host origins. An unexpectedly large number of host-type T cells were recovered from the spleens of F1----P chimeras, amounting to as high as 45 and 25% of total T cells at 6 and 14 weeks after bone marrow transplantation (BMT), respectively. To the contrary, the residual host-type T cells in the spleens of P----F1 chimeras disappeared quickly, resulting in less than 0.1% of total T cells at 6 weeks after BMT. It was also revealed that the number of host-type T cells in the spleens of F1----P chimeras decreased in proportion to increase of radiation dose given to the recipients

Stellar Photometric Structures of the Host Galaxies of Nearby Type 1 Active Galactic Nuclei

Energy Technology Data Exchange (ETDEWEB)

Kim, Minjin [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Ho, Luis C. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Peng, Chien Y. [Giant Magellan Telescope Corporation, 251 S. Lake Ave., Suite 300, Pasadena, CA 91101 (United States); Barth, Aaron J. [Department of Physics and Astronomy, University of California at Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697-4575 (United States); Im, Myungshin, E-mail: mkim@kasi.re.kr, E-mail: lho.pku@gmail.com, E-mail: peng@gmto.org, E-mail: barth@uci.edu, E-mail: mim@astro.snu.ac.kr [Department of Physics and Astronomy, Frontier Physics Research Division (FPRD), Seoul National University, Seoul (Korea, Republic of)

2017-10-01

We present detailed image analysis of rest-frame optical images of 235 low-redshift ( z ≲ 0.35) Type 1 active galactic nuclei (AGNs) observed with the Hubble Space Telescope . The high-resolution images enable us to perform rigorous two-dimensional image modeling to decouple the luminous central point source from the host galaxy, which, when warranted, is further decomposed into its principal structural components (bulge, bar, and disk). In many cases, care must be taken to account for structural complexities such as spiral arms, tidal features, and overlapping or interacting companion galaxies. We employ Fourier modes to characterize the degree of asymmetry of the light distribution of the stars as a quantitative measure of morphological distortion due to interactions or mergers. We examine the dependence of the physical parameters of the host galaxies on the properties of the AGNs, namely, radio-loudness and the width of the broad emission lines. In accordance with previous studies, narrow-line (H β FWHM ≤ 2000 km s{sup −1}) Type 1 AGNs, in contrast to their broad-line (H β FWHM > 2000 km s{sup −1}) counterparts, are preferentially hosted in later-type, lower-luminosity galaxies, which have a higher incidence of pseudo-bulges, are more frequently barred, and are less morphologically disturbed. This suggests that narrow-line Type 1 AGNs experienced a more quiescent evolutionary history driven primarily by internal secular evolution instead of external dynamical perturbations. The fraction of AGN hosts showing merger signatures is larger for more luminous sources. Radio-loud AGNs generally preferentially live in earlier-type (bulge-dominated), more massive hosts, although a minority of them appear to contain a significant disk component. We do not find convincing evidence for enhanced merger signatures in the radio-loud population.

Lawrence Livermore National Laboratory Workshop Characterization of Pathogenicity, Virulence and Host-Pathogen Interactions

Energy Technology Data Exchange (ETDEWEB)

Krishnan, A

2006-08-30

area of host-pathogen interactions as well as policy makers from federal agencies. The main objectives of the workshop are: (1) to assess the current national needs, capabilities, near-term technologies, and future challenges in applying various diagnostics tools to public health and bio-defense; (2) to evaluate the utility and feasibility of host-response and pathogen biomarker profiling in the diagnosis and management of infectious diseases; and (3) to create a comprehensive developmental strategy from proof-of-concept, through validation, to deployment of appropriate advanced technology for the clinical/public health and bio-defense environments.

The Role of Programmed Cell Death Ligand-1 (PD-L1/CD274) in the Development of Graft versus Host Disease

Science.gov (United States)

Al-Chaqmaqchi, Heevy; Sadeghi, Behnam; Abedi-Valugerdi, Manuchehr; Al-Hashmi, Sulaiman; Fares, Mona; Kuiper, Raoul; Lundahl, Joachim

2013-01-01

Programmed cell death ligand-1 (PD-L1/CD274) is an immunomodulatory molecule involved in cancer and complications of bone marrow transplantation, such as graft rejection and graft-versus-host disease. The present study was designed to assess the dynamic expression of this molecule after hematopoietic stem cell transplantation in relation to acute graft-versus-host disease. Female BALB/c mice were conditioned with busulfan and cyclophosphamide and transplanted with either syngeneic or allogeneic (male C57BL/6 mice) bone marrow and splenic cells. The expression of PD-L1 was evaluated at different time points employing qPCR, western blot and immunohistochemistry. Allogeneic- but not syngeneic-transplanted animals exhibited a marked up-regulation of PD-L1 expression in the muscle and kidney, but not the liver, at days 5 and 7 post transplantation. In mice transplanted with allogeneic bone marrow cells, the enhanced expression of PD-L1 was associated with high serum levels of IFNγ and TNFα at corresponding intervals. Our findings demonstrate that PD-L1 is differently induced and expressed after allogeneic transplantation than it is after syngeneic transplantation, and that it is in favor of target rather than non-target organs at the early stages of acute graft-versus-host disease. This is the first study to correlate the dynamics of PD-L1 at the gene-, protein- and activity levels with the early development of acute graft-versus-host disease. Our results suggest that the higher expression of PD-L1 in the muscle and kidney (non-target tissues) plays a protective role in skeletal muscle during acute graft-versus-host disease. PMID:23593203

Measurement of the D{sup *{+-}} meson cross section and extraction of the charm contribution, F{sup c}{sub 2}(x, Q{sup 2}), to the proton structure in deep inelastic ep scattering with the H1 detector at HERA

Energy Technology Data Exchange (ETDEWEB)

Jung, Andreas Werner

2009-01-15

Inclusive production of D{sup *} mesons in deep inelastic scattering at HERA is studied using data taken with the H1 detector in the years 2004 to 2007 corresponding to an integrated luminosity of 347 pb{sup -1}. The measurement covers the region 51.5 GeV and vertical stroke {eta}(D{sup *}) vertical stroke < 1.5. The present measurement is based on an eightfold increased statistics compared to the previous H1 publication and provides a significantly reduced systematic error. Single and double-differential cross sections are compared to leading and next-to-leading order perturbative QCD predictions. The charm contribution, F{sup c}{sub 2} (x,Q{sup 2}), to the proton structure in different QCD evolution schemes is derived from the D{sup *} cross sections and compared to next-to-leading order perturbative QCD predictions. This F{sup c}{sub 2} measurement is performed using a factor of 18 more data compared to the previous H1 publication. The present thesis additionally describes a successfully completed hardware project: The commissioning and optimisation of the third level of the H1 Fast Track Trigger (FTT), which was fully operational from 2006 onwards. The FTT is integrated in the first three levels of the H1 trigger system and provides enhanced selectivity for events with charged particles. The third trigger level of the FTT performs a track-based event reconstruction within a latency of about 100 {mu}s. The third trigger level of the FTT is realised by a farm of PowerPC boards. Furthermore, the FTT simulation is now incorporated into the H1 trigger simulation. (orig.)

Influence of milling time on microstructure and magnetic properties of Fe{sub 80}P{sub 11}C{sub 9} alloy produced by mechanical alloying

Energy Technology Data Exchange (ETDEWEB)

Taghvaei, A.H. [Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Ghajari, F., E-mail: fati.ghajari@gmail.com [Department of Materials Science and Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Markó, D. [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); Prashanth, K.G. [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); Additive manufacturing Center, Sandvik AB, 81181 Sandviken (Sweden)

2015-12-01

Fe{sub 80}P{sub 11}C{sub 9} alloy with amorphous/nanocrytalline microstructure has been synthesized by mechanical alloying of the elemental powders. The microstructure, thermal behavior and morphology of the produced powders have been studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), respectively. The crystallite size, lattice strain and fraction of the amorphous phase have been calculated by Rietveld refinement method. The results indicate that the powders microstructure consists of α-Fe(P,C) nanocrystals with an average diameter of 9 nm±1 nm dispersed in the amorphous matrix after 90 h of milling. Moreover, the fraction of amorphous phase initially increases up to 90 h of milling and then decreases after 120 h of milling, as a result of mechanical crystallization and formation of Fe{sub 2}P phase. The magnetic measurements show that while the saturation magnetization decreases continuously with the milling time, the coercivity exhibits a complicated trend. The correlation between microstructural changes and magnetic properties has been discussed in detail. - Highlights: • Glass formation was investigated in Fe{sub 80}P{sub 11}C{sub 9} by mechanical alloying. • Structural parameters were calculated by Rietveld refinement method. • Milling first increased and then decreased the fraction of amorphous phase. • Magnetic properties were significantly changed upon milling.

Microbial production host selection for converting second-generation feedstocks into bioproducts

Directory of Open Access Journals (Sweden)

van Groenestijn Johan W

2009-12-01

Full Text Available Abstract Background Increasingly lignocellulosic biomass hydrolysates are used as the feedstock for industrial fermentations. These biomass hydrolysates are complex mixtures of different fermentable sugars, but also inhibitors and salts that affect the performance of the microbial production host. The performance of six industrially relevant microorganisms, i.e. two bacteria (Escherichia coli and Corynebacterium glutamicum, two yeasts (Saccharomyces cerevisiae and Pichia stipitis and two fungi (Aspergillus niger and Trichoderma reesei were compared for their (i ability to utilize monosaccharides present in lignocellulosic hydrolysates, (ii resistance against inhibitors present in lignocellulosic hydrolysates, (iii their ability to utilize and grow on different feedstock hydrolysates (corn stover, wheat straw, sugar cane bagasse and willow wood. The feedstock hydrolysates were generated in two manners: (i thermal pretreatment under mild acid conditions followed by enzymatic hydrolysis and (ii a non-enzymatic method in which the lignocellulosic biomass is pretreated and hydrolyzed by concentrated sulfuric acid. Moreover, the ability of the selected hosts to utilize waste glycerol from the biodiesel industry was evaluated. Results Large differences in the performance of the six tested microbial production hosts were observed. Carbon source versatility and inhibitor resistance were the major discriminators between the performances of these microorganisms. Surprisingly all 6 organisms performed relatively well on pretreated crude feedstocks. P. stipitis and A. niger were found to give the overall best performance C. glutamicum and S. cerevisiae were shown to be the least adapted to renewable feedstocks. Conclusion Based on the results obtained we conclude that a substrate oriented instead of the more commonly used product oriented approach towards the selection of a microbial production host will avoid the requirement for extensive metabolic

Preparative separation of C{sub 19}-diterpenoid alkaloids from Aconitum carmichaelii Debx by pH zone-refining counter-current chromatography

Energy Technology Data Exchange (ETDEWEB)

Liu, Dahui [Institute of Medicinal Plants, Yunnan Academy of Agricultural Sciences, Kunming (China); Shu, Xikai; Wang, Xiao; Fang, Lei; Huang, Luqi, E-mail: wxjn1998@126.com [Shandong Analysis and Test Center, Shandong Academy of Sciences, Jinan, Shandong (China); Xi, Xingjun; Zheng, Zhenjia [China National institute of Standardization, Beijing (China)

2013-11-01

The technique of pH-zone-refining counter-current chromatography was successfully applied to preparatively separate three C{sub 19}-diterpenoid alkaloids from the crude extracts of Aconitum carmichaelii for the first time using a two-phase solvent system of petroleum ether-ethyl acetate-methanol-water (5:5:1:9, v/v/v/v). Mesaconitine (I), hypaconitine (II), and deoxyaconitine (III) were obtained from 2.5 g of the crude alkaloids in a one-step separation; the yields were 4.16%, 16.96%, and 5.05%, respectively. The purities of compounds I, II, and III were 93.0%, 95%, and 96%, respectively, as determined by HPLC. The chemical structures of the three compounds were identified by electrospray ionization mass spectrometry (ESI-MS) and NMR. (author)

Host range of antibiotic resistance genes in wastewater treatment plant influent and effluent.

Science.gov (United States)

Hultman, Jenni; Tamminen, Manu; Pärnänen, Katariina; Cairns, Johannes; Karkman, Antti; Virta, Marko

2018-04-01

Wastewater treatment plants (WWTPs) collect wastewater from various sources for a multi-step treatment process. By mixing a large variety of bacteria and promoting their proximity, WWTPs constitute potential hotspots for the emergence of antibiotic resistant bacteria. Concerns have been expressed regarding the potential of WWTPs to spread antibiotic resistance genes (ARGs) from environmental reservoirs to human pathogens. We utilized epicPCR (Emulsion, Paired Isolation and Concatenation PCR) to detect the bacterial hosts of ARGs in two WWTPs. We identified the host distribution of four resistance-associated genes (tetM, int1, qacEΔ1and blaOXA-58) in influent and effluent. The bacterial hosts of these resistance genes varied between the WWTP influent and effluent, with a generally decreasing host range in the effluent. Through 16S rRNA gene sequencing, it was determined that the resistance gene carrying bacteria include both abundant and rare taxa. Our results suggest that the studied WWTPs mostly succeed in decreasing the host range of the resistance genes during the treatment process. Still, there were instances where effluent contained resistance genes in bacterial groups not carrying these genes in the influent. By permitting exhaustive profiling of resistance-associated gene hosts in WWTP bacterial communities, the application of epicPCR provides a new level of precision to our resistance gene risk estimates.

Epitaxial growth of 3C-SiC by using C{sub 60} as a carbon source; Untersuchungen zum epitaktischen Wachstum von 3C-SiC bei Verwendung einer C{sub 60}-Kohlenstoffquelle

Energy Technology Data Exchange (ETDEWEB)

Schreiber, Sascha

2006-01-15

Within this work epitaxial 3C-SiC-films were grown on Si(001) substrates and on ion beam synthesized 3C-SiC(001) pseudo substrates. A rather new process was used which is based on the simultaneous deposition of C60 and Si. In order to set up the necessary experimental conditions an ultra-high vacuum chamber has been designed and built. A RHEED system was used to examine SiC film growth in-situ. Using the described technique 3C-SiC films were grown void-free on Si(001) substrates. Deposition rates of C60 and Si were chosen adequately to maintain a Si:C ratio of approximately one during the deposition process. It was shown that stoichiometric and epitaxial 3C-SiC growth with the characteristic relationship (001)[110]Si(001)[110]3C-SiC could be achieved. TEM investigations revealed that the grown 3C-SiC films consist of individual grains that extend from the Si substrate to the film surface. Two characteristic grain types could be identified. The correlation between structure and texture of void-free grown 3C-SiC films and film thickness was studied by X-ray diffraction (XRD). Pole figure measurements showed that thin films only contain first-order 3C-SiC twins. With higher film thickness also second-order twins are found which are located as twin lamellae in grain type 2. Improvement of polar texture with increasing film thickness couldn't be observed in the investigated range of up to 550 nm. On ion beam synthesized 3C-SiC pseudo substrates homoepitaxial 3C-SiC growth could be demonstrated for the first time by using a C{sub 60} carbon source. In respect to the crystalline quality of the grown films the surface quality of the used substrates was identified as a crucial factor. Furthermore a correlation between the ratio of deposition rates of C{sub 60} and Si and 3C-SiC film quality could be found. Under silicon-rich conditions, i.e. with a Si:C ratio of slightly greater one, homoepitaxial 3C-SiC layer-by-layer growth can be achieved. Films grown under these

Intracellular fate of Ureaplasma parvum entrapped by host cellular autophagy.

Science.gov (United States)

Nishiumi, Fumiko; Ogawa, Michinaga; Nakura, Yukiko; Hamada, Yusuke; Nakayama, Masahiro; Mitobe, Jiro; Hiraide, Atsushi; Sakai, Norio; Takeuchi, Makoto; Yoshimori, Tamotsu; Yanagihara, Itaru

2017-06-01

Genital mycoplasmas, including Ureaplasma spp., are among the smallest human pathogenic bacteria and are associated with preterm birth. Electron microscopic observation of U. parvum showed that these prokaryotes have a regular, spherical shape with a mean diameter of 146 nm. U. parvum was internalized into HeLa cells by clathrin-mediated endocytosis and survived for at least 14 days around the perinuclear region. Intracellular U. parvum reached endosomes in HeLa cells labeled with EEA1, Rab7, and LAMP-1 within 1 to 3 hr. After 3 hr of infection, U. parvum induced the cytosolic accumulation of galectin-3 and was subsequently entrapped by the autophagy marker LC3. However, when using atg7 -/- MEF cells, autophagy was inadequate for the complete elimination of U. parvum in HeLa cells. U. parvum also colocalized with the recycling endosome marker Rab11. Furthermore, the exosomes purified from infected HeLa cell culture medium included U. parvum. In these purified exosomes ureaplasma lipoprotein multiple banded antigen, host cellular annexin A2, CD9, and CD63 were detected. This research has successfully shown that Ureaplasma spp. utilize the host cellular membrane compartments possibly to evade the host immune system. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

An Aphid Effector Targets Trafficking Protein VPS52 in a Host-Specific Manner to Promote Virulence1[OPEN

Science.gov (United States)

2017-01-01

Plant- and animal-feeding insects secrete saliva inside their hosts, containing effectors, which may promote nutrient release and suppress immunity. Although for plant pathogenic microbes it is well established that effectors target host proteins to modulate host cell processes and promote disease, the host cell targets of herbivorous insects remain elusive. Here, we show that the existing plant pathogenic microbe effector paradigm can be extended to herbivorous insects in that effector-target interactions inside host cells modify critical host processes to promote plant susceptibility. We showed that the effector Mp1 from Myzus persicae associates with the host Vacuolar Protein Sorting Associated Protein52 (VPS52). Using natural variants, we provide a strong link between effector virulence activity and association with VPS52, and show that the association is highly specific to M. persicae-host interactions. Also, coexpression of Mp1, but not Mp1-like variants, specifically with host VPS52s resulted in effector relocalization to vesicle-like structures that associate with prevacuolar compartments. We show that high VPS52 levels negatively impact virulence, and that aphids are able to reduce VPS52 levels during infestation, indicating that VPS52 is an important virulence target. Our work is an important step forward in understanding, at the molecular level, how a major agricultural pest promotes susceptibility during infestation of crop plants. We give evidence that an herbivorous insect employs effectors that interact with host proteins as part of an effective virulence strategy, and that these effectors likely function in a species-specific manner. PMID:28100451

Diversity in host clone performance within a Chinese hamster ovary cell line.

Science.gov (United States)

O'Callaghan, Peter M; Berthelot, Maud E; Young, Robert J; Graham, James W A; Racher, Andrew J; Aldana, Dulce

2015-01-01

Much effort has been expended to improve the capabilities of individual Chinese hamster ovary (CHO) host cell lines to synthesize recombinant therapeutic proteins (rPs). However, given the increasing variety in rP molecular types and formats it may be advantageous to employ a toolbox of CHO host cell lines in biomanufacturing. Such a toolbox would contain a panel of hosts with specific capabilities to synthesize certain molecular types at high volumetric concentrations and with the correct product quality (PQ). In this work, we examine a panel of clonally derived host cell lines isolated from CHOK1SV for the ability to manufacture two model proteins, an IgG4 monoclonal antibody (Mab) and an Fc-fusion protein (etanercept). We show that these host cell lines vary in their relative ability to synthesize these proteins in transient and stable pool production format. Furthermore, we examined the PQ attributes of the stable pool-produced Mab and etanercept (by N-glycan ultra performance liquid chromatography (UPLC) and liquid chromatography - tandem mass spectrometry (LC-MS/MS), respectively), and uncovered substantial variation between the host cell lines in Mab N-glycan micro-heterogeneity and etanercept N and O-linked macro-heterogeneity. To further investigate the capabilities of these hosts to act as cell factories, we examined the glycosylation pathway gene expression profiles as well as the levels of endoplasmic reticulum (ER) and mitochondria in the untransfected hosts. We uncovered a moderate correlation between ER mass and the volumetric product concentration in transient and stable pool Mab production. This work demonstrates the utility of leveraging diversity within the CHOK1SV pool to identify new host cell lines with different performance characteristics. © 2015 American Institute of Chemical Engineers.

Host specificity in bat ectoparasites: a natural experiment.

Science.gov (United States)

Seneviratne, Sampath S; Fernando, H Chandrika; Udagama-Randeniya, Preethi V

2009-07-15

We undertook a field study to determine patterns of specialisation of ectoparasites in cave-dwelling bats in Sri Lanka. The hypothesis tested was that strict host specificity (monoxeny) could evolve through the development of differential species preferences through association with the different host groups. Three species of cave-dwelling bats were chosen to represent a wide range of host-parasite associations (monoxeny to polyxeny), and both sympatric and allopatric roosting assemblages. Of the eight caves selected, six caves were "allopatric" roosts where two of each housed only one of the three host species examined: Rousettus leschenaulti (Pteropodidae), Rhinolophus rouxi and Hipposideros speoris (Rhinolophidae). The remaining two caves were "sympatric" roosts and housed all three host species. Thirty bats of each species were examined for ectoparasites in each cave, which resulted in a collection of nycteribiid and streblid flies, an ischnopsyllid bat flea, argasid and ixodid ticks, and mites belonging to three families. The host specificity of bat parasites showed a trend to monoxeny in which 70% of the 30 species reported were monoxenous. Odds ratios derived from chi(2)-tests revealed two levels of host preferences in less-specific parasites (i) the parasite was found on two host species under conditions of both host sympatry and host allopatry, with a preference for a single host in the case of host sympatry and (ii) the preference for a single host was very high, hence under conditions of host sympatry, it was confined to the preferred host only. However, under conditions of host allopatry, it utilized both hosts. There appears to be an increasing prevalence in host preferences of the parasites toward confinement to a single host species. The ecological isolation of the bat hosts and a long history of host-parasite co-existence could have contributed to an overall tendency of bat ectoparasites to become specialists, here reflected in the high percentage

Cultured representatives of two major phylogroups of human colonic Faecalibacterium prausnitzii can utilize pectin, uronic acids, and host-derived substrates for growth.

Science.gov (United States)

Lopez-Siles, Mireia; Khan, Tanweer M; Duncan, Sylvia H; Harmsen, Hermie J M; Garcia-Gil, L Jesús; Flint, Harry J

2012-01-01

Faecalibacterium prausnitzii is one of the most abundant commensal bacteria in the healthy human large intestine, but information on genetic diversity and substrate utilization is limited. Here, we examine the phylogeny, phenotypic characteristics, and influence of gut environmental factors on growth of F. prausnitzii strains isolated from healthy subjects. Phylogenetic analysis based on the 16S rRNA sequences indicated that the cultured strains were representative of F. prausnitzii sequences detected by direct analysis of fecal DNA and separated the available isolates into two phylogroups. Most F. prausnitzii strains tested grew well under anaerobic conditions on apple pectin. Furthermore, F. prausnitzii strains competed successfully in coculture with two other abundant pectin-utilizing species, Bacteroides thetaiotaomicron and Eubacterium eligens, with apple pectin as substrate, suggesting that this species makes a contribution to pectin fermentation in the colon. Many F. prausnitzii isolates were able to utilize uronic acids for growth, an ability previously thought to be confined to Bacteroides spp. among human colonic anaerobes. Most strains grew on N-acetylglucosamine, demonstrating an ability to utilize host-derived substrates. All strains tested were bile sensitive, showing at least 80% growth inhibition in the presence of 0.5 μg/ml bile salts, while inhibition at mildly acidic pH was strain dependent. These attributes help to explain the abundance of F. prausnitzii in the colonic community but also suggest factors in the gut environment that may limit its distribution.

Electronic properties of freestanding Ti{sub 3}C{sub 2}T{sub x} MXene monolayers

Energy Technology Data Exchange (ETDEWEB)

Miranda, A.; Lorke, A. [Department of Physics, Universität Duisburg-Essen, Duisburg 47058 (Germany); Halim, J. [Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Thin Film Physics Division, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping (Sweden); Barsoum, M. W. [Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104 (United States)

2016-01-18

We report on the electrical characterization of single MXene Ti{sub 3}C{sub 2}T{sub x} flakes (where T is a surface termination) and demonstrate the metallic nature of their conductivities. We also show that the carrier density can be modulated by an external gate voltage. The density of free carriers is estimated to be 8 ± 3 × 10{sup 21} cm{sup −3} while their mobility is estimated to be 0.7 ± 0.2 cm{sup 2}/V s. Electrical measurements, in the presence of a magnetic field, show a small, but clearly discernable, quadratic increase in conductance at 2.5 K.

Limits on stellar companions to exoplanet host stars with eccentric planets

International Nuclear Information System (INIS)

Kane, Stephen R.; Hinkel, Natalie R.; Howell, Steve B.; Horch, Elliott P.; Feng, Ying; Wright, Jason T.; Ciardi, David R.; Everett, Mark E.; Howard, Andrew W.

2014-01-01

Though there are now many hundreds of confirmed exoplanets known, the binarity of exoplanet host stars is not well understood. This is particularly true of host stars that harbor a giant planet in a highly eccentric orbit since these are more likely to have had a dramatic dynamical history that transferred angular momentum to the planet. Here we present observations of four exoplanet host stars that utilize the excellent resolving power of the Differential Speckle Survey Instrument on the Gemini North telescope. Two of the stars are giants and two are dwarfs. Each star is host to a giant planet with an orbital eccentricity >0.5 and whose radial velocity (RV) data contain a trend in the residuals to the Keplerian orbit fit. These observations rule out stellar companions 4-8 mag fainter than the host star at passbands of 692 nm and 880 nm. The resolution and field of view of the instrument result in exclusion radii of 0.''05-1.''4, which excludes stellar companions within several AU of the host star in most cases. We further provide new RVs for the HD 4203 system that confirm that the linear trend previously observed in the residuals is due to an additional planet. These results place dynamical constraints on the source of the planet's eccentricities, place constraints on additional planetary companions, and inform the known distribution of multiplicity amongst exoplanet host stars.

Simulation of the soft-landing and adsorption of C{sub 60} molecules on a graphite substrate and computation of their scanning-tunnelling-microscopy-like images

Energy Technology Data Exchange (ETDEWEB)

Rafii-Tabar, H. [Computational Nano-Science Research Group, Centre for Numerical Modelling and Process Analysis, School of Computing and Mathematical Sciences, University of Greenwich, Greenwich, London (United Kingdom); Jurczyszyn, L.; Stankiewicz, B. [Institute of Experimental Physics, University of Wroclaw, Wroclaw (Poland)

2000-07-03

A constant-temperature molecular dynamics (MD) simulation was performed to model the soft-landing and adsorption of C{sub 60} molecules on a graphite substrate with the C{sub 60}s treated as soft molecules and released individually towards the substrate. The intra-molecular and intra-planar covalently bonding interactions were modelled by very accurate many-body potentials, and the non-bonding forces were derived from various pairwise potentials. The simulation extended over 1.6 million time steps covering a significant period of 160 picoseconds. The final alignment of the molecules on the surface agrees closely with that observed in an experiment based on scanning tunnelling microscopy (STM) on the same system, performed at room temperature and under ultrahigh-vacuum (UHV) conditions. Using a tungsten tip in a constant-current mode of imaging, we have also computed the STM-like images of one of the adsorbed molecules using a formulation of the STM tunnelling current based on Keldysh's non-equilibrium Green function formalism. Our aim has been to search for tip-induced states, which were speculated, on the basis of another STM-based experiment, performed in air, to form one of the possible origins of the extra features purported to have been observed in that experiment. We have not obtained any such states. (author)

Adaptation to human populations is revealed by within-host polymorphisms in HIV-1 and hepatitis C virus.

Directory of Open Access Journals (Sweden)

Art F Y Poon

2007-03-01

Full Text Available CD8(+ cytotoxic T-lymphocytes (CTLs perform a critical role in the immune control of viral infections, including those caused by human immunodeficiency virus type 1 (HIV-1 and hepatitis C virus (HCV. As a result, genetic variation at CTL epitopes is strongly influenced by host-specific selection for either escape from the immune response, or reversion due to the replicative costs of escape mutations in the absence of CTL recognition. Under strong CTL-mediated selection, codon positions within epitopes may immediately "toggle" in response to each host, such that genetic variation in the circulating virus population is shaped by rapid adaptation to immune variation in the host population. However, this hypothesis neglects the substantial genetic variation that accumulates in virus populations within hosts. Here, we evaluate this quantity for a large number of HIV-1- (n > or = 3,000 and HCV-infected patients (n > or = 2,600 by screening bulk RT-PCR sequences for sequencing "mixtures" (i.e., ambiguous nucleotides, which act as site-specific markers of genetic variation within each host. We find that nonsynonymous mixtures are abundant and significantly associated with codon positions under host-specific CTL selection, which should deplete within-host variation by driving the fixation of the favored variant. Using a simple model, we demonstrate that this apparently contradictory outcome can be explained by the transmission of unfavorable variants to new hosts before they are removed by selection, which occurs more frequently when selection and transmission occur on similar time scales. Consequently, the circulating virus population is shaped by the transmission rate and the disparity in selection intensities for escape or reversion as much as it is shaped by the immune diversity of the host population, with potentially serious implications for vaccine design.

Yersinia pseudotuberculosis Spatially Controls Activation and Misregulation of Host Cell Rac1.

Directory of Open Access Journals (Sweden)

2005-10-01

Full Text Available Yersinia pseudotuberculosis binds host cells and modulates the mammalian Rac1 guanosine triphosphatase (GTPase at two levels. Activation of Rac1 results from integrin receptor engagement, while misregulation is promoted by translocation of YopE and YopT proteins into target cells. Little is known regarding how these various factors interplay to control Rac1 dynamics. To investigate these competing processes, the localization of Rac1 activation was imaged microscopically using fluorescence resonance energy transfer. In the absence of translocated effectors, bacteria induced activation of the GTPase at the site of bacterial binding. In contrast, the entire cellular pool of Rac1 was inactivated shortly after translocation of YopE RhoGAP. Inactivation required membrane localization of Rac1. The translocated protease YopT had very different effects on Rac1. This protein, which removes the membrane localization site of Rac1, did not inactivate Rac1, but promoted entry of cleaved activated Rac1 molecules into the host cell nucleus, allowing Rac1 to localize with nuclear guanosine nucleotide exchange factors. As was true for YopE, membrane-associated Rac1 was the target for YopT, indicating that the two translocated effectors may compete for the same pool of target protein. Consistent with the observation that YopE inactivation requires membrane localization of Rac1, the presence of YopT in the cell interfered with the action of the YopE RhoGAP. As a result, interaction of target cells with a strain that produces both YopT and YopE resulted in two spatially distinct pools of Rac1: an inactive cytoplasmic pool and an activated nuclear pool. These studies demonstrate that competition between bacterial virulence factors for access to host substrates is controlled by the spatial arrangement of a target protein. In turn, the combined effects of translocated bacterial proteins are to generate pools of a single signaling molecule with distinct localization and

Congruence and diversity of butterfly-host plant associations at higher taxonomic levels.

Science.gov (United States)

Ferrer-Paris, José R; Sánchez-Mercado, Ada; Viloria, Ángel L; Donaldson, John

2013-01-01

We aggregated data on butterfly-host plant associations from existing sources in order to address the following questions: (1) is there a general correlation between host diversity and butterfly species richness?, (2) has the evolution of host plant use followed consistent patterns across butterfly lineages?, (3) what is the common ancestral host plant for all butterfly lineages? The compilation included 44,148 records from 5,152 butterfly species (28.6% of worldwide species of Papilionoidea) and 1,193 genera (66.3%). The overwhelming majority of butterflies use angiosperms as host plants. Fabales is used by most species (1,007 spp.) from all seven butterfly families and most subfamilies, Poales is the second most frequently used order, but is mostly restricted to two species-rich subfamilies: Hesperiinae (56.5% of all Hesperiidae), and Satyrinae (42.6% of all Nymphalidae). We found a significant and strong correlation between host plant diversity and butterfly species richness. A global test for congruence (Parafit test) was sensitive to uncertainty in the butterfly cladogram, and suggests a mixed system with congruent associations between Papilionidae and magnoliids, Hesperiidae and monocots, and the remaining subfamilies with the eudicots (fabids and malvids), but also numerous random associations. The congruent associations are also recovered as the most probable ancestral states in each node using maximum likelihood methods. The shift from basal groups to eudicots appears to be more likely than the other way around, with the only exception being a Satyrine-clade within the Nymphalidae that feed on monocots. Our analysis contributes to the visualization of the complex pattern of interactions at superfamily level and provides a context to discuss the timing of changes in host plant utilization that might have promoted diversification in some butterfly lineages.

Congruence and diversity of butterfly-host plant associations at higher taxonomic levels.

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José R Ferrer-Paris

Full Text Available We aggregated data on butterfly-host plant associations from existing sources in order to address the following questions: (1 is there a general correlation between host diversity and butterfly species richness?, (2 has the evolution of host plant use followed consistent patterns across butterfly lineages?, (3 what is the common ancestral host plant for all butterfly lineages? The compilation included 44,148 records from 5,152 butterfly species (28.6% of worldwide species of Papilionoidea and 1,193 genera (66.3%. The overwhelming majority of butterflies use angiosperms as host plants. Fabales is used by most species (1,007 spp. from all seven butterfly families and most subfamilies, Poales is the second most frequently used order, but is mostly restricted to two species-rich subfamilies: Hesperiinae (56.5% of all Hesperiidae, and Satyrinae (42.6% of all Nymphalidae. We found a significant and strong correlation between host plant diversity and butterfly species richness. A global test for congruence (Parafit test was sensitive to uncertainty in the butterfly cladogram, and suggests a mixed system with congruent associations between Papilionidae and magnoliids, Hesperiidae and monocots, and the remaining subfamilies with the eudicots (fabids and malvids, but also numerous random associations. The congruent associations are also recovered as the most probable ancestral states in each node using maximum likelihood methods. The shift from basal groups to eudicots appears to be more likely than the other way around, with the only exception being a Satyrine-clade within the Nymphalidae that feed on monocots. Our analysis contributes to the visualization of the complex pattern of interactions at superfamily level and provides a context to discuss the timing of changes in host plant utilization that might have promoted diversification in some butterfly lineages.

Stellar Photometric Structures of the Host Galaxies of Nearby Type 1 Active Galactic Nuclei

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Kim, Minjin; Ho, Luis C.; Peng, Chien Y.; Barth, Aaron J.; Im, Myungshin

2017-10-01

We present detailed image analysis of rest-frame optical images of 235 low-redshift (z ≲ 0.35) Type 1 active galactic nuclei (AGNs) observed with the Hubble Space Telescope. The high-resolution images enable us to perform rigorous two-dimensional image modeling to decouple the luminous central point source from the host galaxy, which, when warranted, is further decomposed into its principal structural components (bulge, bar, and disk). In many cases, care must be taken to account for structural complexities such as spiral arms, tidal features, and overlapping or interacting companion galaxies. We employ Fourier modes to characterize the degree of asymmetry of the light distribution of the stars as a quantitative measure of morphological distortion due to interactions or mergers. We examine the dependence of the physical parameters of the host galaxies on the properties of the AGNs, namely, radio-loudness and the width of the broad emission lines. In accordance with previous studies, narrow-line (Hβ FWHM ≤ 2000 km s-1) Type 1 AGNs, in contrast to their broad-line (Hβ FWHM > 2000 km s-1) counterparts, are preferentially hosted in later-type, lower-luminosity galaxies, which have a higher incidence of pseudo-bulges, are more frequently barred, and are less morphologically disturbed. This suggests that narrow-line Type 1 AGNs experienced a more quiescent evolutionary history driven primarily by internal secular evolution instead of external dynamical perturbations. The fraction of AGN hosts showing merger signatures is larger for more luminous sources. Radio-loud AGNs generally preferentially live in earlier-type (bulge-dominated), more massive hosts, although a minority of them appear to contain a significant disk component. We do not find convincing evidence for enhanced merger signatures in the radio-loud population. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute

Host age modulates within-host parasite competition.

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Izhar, Rony; Routtu, Jarkko; Ben-Ami, Frida

2015-05-01

In many host populations, one of the most striking differences among hosts is their age. While parasite prevalence differences in relation to host age are well known, little is known on how host age impacts ecological and evolutionary dynamics of diseases. Using two clones of the water flea Daphnia magna and two clones of its bacterial parasite Pasteuria ramosa, we examined how host age at exposure influences within-host parasite competition and virulence. We found that multiply-exposed hosts were more susceptible to infection and suffered higher mortality than singly-exposed hosts. Hosts oldest at exposure were least often infected and vice versa. Furthermore, we found that in young multiply-exposed hosts competition was weak, allowing coexistence and transmission of both parasite clones, whereas in older multiply-exposed hosts competitive exclusion was observed. Thus, age-dependent parasite exposure and host demography (age structure) could together play an important role in mediating parasite evolution. At the individual level, our results demonstrate a previously unnoticed interaction of the host's immune system with host age, suggesting that the specificity of immune function changes as hosts mature. Therefore, evolutionary models of parasite virulence might benefit from incorporating age-dependent epidemiological parameters. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Activation of Host IRE1α-Dependent Signaling Axis Contributes the Intracellular Parasitism of Brucella melitensis

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Aseem Pandey

2018-04-01

Full Text Available Brucella spp. are intracellular vacuolar pathogens that causes brucellosis, a worldwide zoonosis of profound importance. We previously demonstrated that the activity of host unfolded protein response (UPR sensor IRE1α (inositol-requiring enzyme 1 and ER-associated autophagy confer susceptibility to Brucella melitensis and Brucella abortus intracellular replication. However, the mechanism by which host IRE1α regulates the pathogen intracellular lifestyle remains elusive. In this study, by employing a diverse array of molecular approaches, including biochemical analyses, fluorescence microscopy imaging, and infection assays using primary cells derived from Ern1 (encoding IRE1 conditional knockout mice, we address this gap in our understanding by demonstrating that a novel IRE1α to ULK1, an important component for autophagy initiation, signaling axis confers susceptibility to Brucella intracellular parasitism. Importantly, deletion or inactivation of key signaling components along this axis, including IRE1α, BAK/BAX, ASK1, and JNK as well as components of the host autophagy system ULK1, Atg9a, and Beclin 1, resulted in striking disruption of Brucella intracellular trafficking and replication. Host kinases in the IRE1α-ULK1 axis, including IRE1α, ASK1, JNK1, and/or AMPKα as well as ULK1, were also coordinately phosphorylated in an IRE1α-dependent fashion upon the pathogen infection. Taken together, our findings demonstrate that the IRE1α-ULK1 signaling axis is subverted by the bacterium to promote intracellular parasitism, and provide new insight into our understanding of the molecular mechanisms of intracellular lifestyle of Brucella.

The cytotoxic type 3 secretion system 1 of Vibrio rewires host gene expression to subvert cell death and activate cell survival pathways.

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De Nisco, Nicole J; Kanchwala, Mohammed; Li, Peng; Fernandez, Jessie; Xing, Chao; Orth, Kim

2017-05-16

Bacterial effectors potently manipulate host signaling pathways. The marine bacterium Vibrio parahaemolyticus ( V. para ) delivers effectors into host cells through two type 3 secretion systems (T3SSs). T3SS1 is vital for V. para survival in the environment, whereas T3SS2 causes acute gastroenteritis in human hosts. Although the natural host is undefined, T3SS1 effectors attack highly conserved cellular processes and pathways to orchestrate nonapoptotic cell death. To understand how the concerted action of T3SS1 effectors globally affects host cell signaling, we compared gene expression changes over time in primary fibroblasts infected with V. para that have a functional T3SS1 (T3SS1 + ) to those in cells infected with V. para lacking T3SS1 (T3SS1 - ). Overall, the host transcriptional response to both T3SS1 + and T3SS1 - V. para was rapid, robust, and temporally dynamic. T3SS1 rewired host gene expression by specifically altering the expression of 398 genes. Although T3SS1 effectors targeted host cells at the posttranslational level to cause cytotoxicity, V. para T3SS1 also precipitated a host transcriptional response that initially activated cell survival and repressed cell death networks. The increased expression of several key prosurvival transcripts mediated by T3SS1 depended on a host signaling pathway that is silenced posttranslationally later in infection. Together, our analysis reveals a complex interplay between the roles of T3SS1 as both a transcriptional and posttranslational manipulator of host cell signaling. Copyright © 2017, American Association for the Advancement of Science.

A minimal SATA III Host Controller based on FPGA

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Liu, Hailiang

2018-03-01

SATA (Serial Advanced Technology Attachment) is an advanced serial bus which has a outstanding performance in transmitting high speed real-time data applied in Personal Computers, Financial Industry, astronautics and aeronautics, etc. In this express, a minimal SATA III Host Controller based on Xilinx Kintex 7 serial FPGA is designed and implemented. Compared to the state-of-art, registers utilization are reduced 25.3% and LUTs utilization are reduced 65.9%. According to the experimental results, the controller works precisely and steady with the reading bandwidth of up to 536 MB per second and the writing bandwidth of up to 512 MB per second, both of which are close to the maximum bandwidth of the SSD(Solid State Disk) device. The host controller is very suitable for high speed data transmission and mass data storage.

Yersinia pestis Requires Host Rab1b for Survival in Macrophages.

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Michael G Connor

2015-10-01

Full Text Available Yersinia pestis is a facultative intracellular pathogen that causes the disease known as plague. During infection of macrophages Y. pestis actively evades the normal phagosomal maturation pathway to establish a replicative niche within the cell. However, the mechanisms used by Y. pestis to subvert killing by the macrophage are unknown. Host Rab GTPases are central mediators of vesicular trafficking and are commonly targeted by bacterial pathogens to alter phagosome maturation and killing by macrophages. Here we demonstrate for the first time that host Rab1b is required for Y. pestis to effectively evade killing by macrophages. We also show that Rab1b is specifically recruited to the Yersinia containing vacuole (YCV and that Y. pestis is unable to subvert YCV acidification when Rab1b expression is knocked down in macrophages. Furthermore, Rab1b knockdown also altered the frequency of association between the YCV with the lysosomal marker Lamp1, suggesting that Rab1b recruitment to the YCV directly inhibits phagosome maturation. Finally, we show that Rab1b knockdown also impacts the pH of the Legionella pneumophila containing vacuole, another pathogen that recruits Rab1b to its vacuole. Together these data identify a novel role for Rab1b in the subversion of phagosome maturation by intracellular pathogens and suggest that recruitment of Rab1b to the pathogen containing vacuole may be a conserved mechanism to control vacuole pH.

Microstructures and mechanical properties of 3D 4-directional, C{sub f}/ZrC–SiC composites using ZrC precursor and polycarbosilane

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Li, Qinggang, E-mail: liqinggang66@gmail.com [School of Material Science and Engineering, University of Jinan, Jinan 250022 (China); Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, Jinan 250022 (China); Dong, Shaoming [Structural Ceramics and Composites Engineering Research Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Wang, Zhi; Shi, Guopu; Ma, Yan [School of Material Science and Engineering, University of Jinan, Jinan 250022 (China); Zhou, Haijun; Wang, Zhen; He, Ping [Structural Ceramics and Composites Engineering Research Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

2013-11-01

Highlights: • Three-dimensional 4-directional C{sub f}/ZrC–SiC composites fabricated by polymer infiltration and pyrolysis. • The microstructure and mechanical properties of the composites were studied. • High-temperature oxidation resistance and anti-ablation properties were evaluated. • Results show the composites have good mechanical and excellent ablative properties. -- Abstract: Three-dimensional 4-directional C{sub f}/ZrC–SiC composites were successfully fabricated by polymer infiltration and pyrolysis combined with ZrC precursor impregnation. The microstructure and mechanical properties of the composites were studied. The composite with PyC/SiC interphase had a bulk density of 2.14 g/cm{sup 3}, an open porosity of 10%, and a bending stress of 474 MPa, and exhibited a non-brittle failure behavior due to propagation and deflection of cracks, and fracture and pullout of fibers. Their high-temperature oxidation resistance and anti-ablation properties were evaluated using a muffle furnace and plasma wind tunnel test. Results show that the composites have good mechanical and excellent ablative properties.

Identifying potential survival strategies of HIV-1 through virus-host protein interaction networks

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Boucher Charles AB

2010-07-01

Full Text Available Abstract Background The National Institute of Allergy and Infectious Diseases has launched the HIV-1 Human Protein Interaction Database in an effort to catalogue all published interactions between HIV-1 and human proteins. In order to systematically investigate these interactions functionally and dynamically, we have constructed an HIV-1 human protein interaction network. This network was analyzed for important proteins and processes that are specific for the HIV life-cycle. In order to expose viral strategies, network motif analysis was carried out showing reoccurring patterns in virus-host dynamics. Results Our analyses show that human proteins interacting with HIV form a densely connected and central sub-network within the total human protein interaction network. The evaluation of this sub-network for connectivity and centrality resulted in a set of proteins essential for the HIV life-cycle. Remarkably, we were able to associate proteins involved in RNA polymerase II transcription with hubs and proteasome formation with bottlenecks. Inferred network motifs show significant over-representation of positive and negative feedback patterns between virus and host. Strikingly, such patterns have never been reported in combined virus-host systems. Conclusions HIV infection results in a reprioritization of cellular processes reflected by an increase in the relative importance of transcriptional machinery and proteasome formation. We conclude that during the evolution of HIV, some patterns of interaction have been selected for resulting in a system where virus proteins preferably interact with central human proteins for direct control and with proteasomal proteins for indirect control over the cellular processes. Finally, the patterns described by network motifs illustrate how virus and host interact with one another.

An update on the clinical utility of extracorporeal photopheresis in the treatment of graft-versus-host disease

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Salem B

2017-03-01

Full Text Available Baheyeldin Salem,1,2 Jennifer Webb,3 David Alex Jacobsohn1,2 1Blood and Marrow Transplant Program, 2Department of Paediatrics, 3Department of Transfusion Medicine, Children’s National Health System, Washington, DC, USA Abstract: Graft-versus-host disease (GVHD continues to be a major complication following allogeneic hematopoietic cell transplantation (allo-HCT with high morbidity and mortality. Corticosteroids are the first-line treatment for GVHD; however, a substantial number of patients go on to require second-line treatment where no single therapeutic modality has been proven to be the most effective. Extracorporeal photopheresis (ECP is an efficient and established therapy for cutaneous T-cell lymphoma, GVHD, rejection after solid organ transplantation and various autoimmune diseases. Although large randomized trials are limited, there is compelling cumulative data on the efficacy of ECP for GVHD, and the response rates, especially for cutaneous involvement, are encouraging. ECP has an excellent safety profile, a well-documented steroid-sparing effect, proven survival benefit and overall quality-of-life improvement. In many institutions, ECP is commonly regarded as the preferred second-line treatment for GVHD. Keywords: GVHD, ECP, immunosuppressive therapy, IST, apheresis, steroid-refractory ­graft-versus-host disease, hematopoietic cell transplantation, graft versus leukemia effect

Host-guest interaction of styrene and ethylbenzene in MIL-53 studied by solid-state NMR.

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Li, Shenhui; Li, Jing; Tang, Jing; Deng, Feng

Solid-state NMR was utilized to explore the host-guest interaction between adsorbate and adsorbent at atomic level to understand the separation mechanism of styrene (St) and ethylbenzene (EB) in MIL-53(Al). 13 C- 27 Al double-resonance NMR experiments revealed that the host-guest interaction between St and MIL-53 was much stronger than that of EB adsorption. In addition, 13 C DIPSHIFT experiments suggested that the adsorbed St was less mobile than EB confined inside the MIL-53 pore. Furthermore, the host-guest interaction model between St, EB and MIL-53 was established on the basis of the spatial proximities information extracted from 2D 1 H- 1 H homo-nuclear correlation NMR experiments. According to the experimental observation from solid-state NMR, it was found that the presence of π-π interaction between St and MIL-53 resulted in the stronger host-guest interaction and less mobility of St. This work provides direct experimental evidence for understanding the separation mechanism of St and EB using MIL-53 as an adsorbent. Copyright © 2017 Elsevier Inc. All rights reserved.

Tick-Host Range Adaptation: Changes in Protein Profiles in Unfed Adult Ixodes scapularis and Amblyomma americanum Saliva Stimulated to Feed on Different Hosts

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Lucas Tirloni

2017-12-01

Full Text Available Understanding the molecular basis of how ticks adapt to feed on different animal hosts is central to understanding tick and tick-borne disease (TBD epidemiology. There is evidence that ticks differentially express specific sets of genes when stimulated to start feeding. This study was initiated to investigate if ticks such as Ixodes scapularis and Amblyomma americanum that are adapted to feed on multiple hosts utilized the same sets of proteins to prepare for feeding. We exposed I. scapularis and A. americanum to feeding stimuli of different hosts (rabbit, human, and dog by keeping unfed adult ticks enclosed in a perforated microfuge in close contact with host skin, but not allowing ticks to attach on host. Our data suggest that ticks of the same species differentially express tick saliva proteins (TSPs when stimulated to start feeding on different hosts. SDS-PAGE and silver staining analysis revealed unique electrophoretic profiles in saliva of I. scapularis and A. americanum that were stimulated to feed on different hosts: rabbit, human, and dog. LC-MS/MS sequencing and pairwise analysis demonstrated that I. scapularis and A. americanum ticks expressed unique protein profiles in their saliva when stimulated to start feeding on different hosts: rabbit, dog, or human. Specifically, our data revealed TSPs that were unique to each treatment and those that were shared between treatments. Overall, we identified a total of 276 and 340 non-redundant I. scapularis and A. americanum TSPs, which we have classified into 28 functional classes including: secreted conserved proteins (unknown functions, proteinase inhibitors, lipocalins, extracellular matrix/cell adhesion, heme/iron metabolism, signal transduction and immunity-related proteins being the most predominant in saliva of unfed ticks. With exception of research on vaccines against Rhipicephalus microplus, which its natural host, cattle, research on vaccine against other ticks relies feeding ticks

On the definition and utilization of heritable variation among hosts in reproduction ratio R0 for infectious diseases.

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Anche, M T; de Jong, M C M; Bijma, P

2014-10-01

Infectious diseases have a major role in evolution by natural selection and pose a worldwide concern in livestock. Understanding quantitative genetics of infectious diseases, therefore, is essential both for understanding the consequences of natural selection and for designing artificial selection schemes in agriculture. The basic reproduction ratio, R0, is the key parameter determining risk and severity of infectious diseases. Genetic improvement for control of infectious diseases in host populations should therefore aim at reducing R0. This requires definitions of breeding value and heritable variation for R0, and understanding of mechanisms determining response to selection. This is challenging, as R0 is an emergent trait arising from interactions among individuals in the population. Here we show how to define breeding value and heritable variation for R0 for genetically heterogeneous host populations. Furthermore, we identify mechanisms determining utilization of heritable variation for R0. Using indirect genetic effects, next-generation matrices and a SIR (Susceptible, Infected and Recovered) model, we show that an individual's breeding value for R0 is a function of its own allele frequencies for susceptibility and infectivity and of population average susceptibility and infectivity. When interacting individuals are unrelated, selection for individual disease status captures heritable variation in susceptibility only, yielding limited response in R0. With related individuals, however, there is a secondary selection process, which also captures heritable variation in infectivity and additional variation in susceptibility, yielding substantially greater response. This shows that genetic variation in susceptibility represents an indirect genetic effect. As a consequence, response in R0 increased substantially when interacting individuals were genetically related.

OLYMPUS: an automated hybrid clustering method in time series gene expression. Case study: host response after Influenza A (H1N1) infection.

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Dimitrakopoulou, Konstantina; Vrahatis, Aristidis G; Wilk, Esther; Tsakalidis, Athanasios K; Bezerianos, Anastasios

2013-09-01

The increasing flow of short time series microarray experiments for the study of dynamic cellular processes poses the need for efficient clustering tools. These tools must deal with three primary issues: first, to consider the multi-functionality of genes; second, to evaluate the similarity of the relative change of amplitude in the time domain rather than the absolute values; third, to cope with the constraints of conventional clustering algorithms such as the assignment of the appropriate cluster number. To address these, we propose OLYMPUS, a novel unsupervised clustering algorithm that integrates Differential Evolution (DE) method into Fuzzy Short Time Series (FSTS) algorithm with the scope to utilize efficiently the information of population of the first and enhance the performance of the latter. Our hybrid approach provides sets of genes that enable the deciphering of distinct phases in dynamic cellular processes. We proved the efficiency of OLYMPUS on synthetic as well as on experimental data. The discriminative power of OLYMPUS provided clusters, which refined the so far perspective of the dynamics of host response mechanisms to Influenza A (H1N1). Our kinetic model sets a timeline for several pathways and cell populations, implicated to participate in host response; yet no timeline was assigned to them (e.g. cell cycle, homeostasis). Regarding the activity of B cells, our approach revealed that some antibody-related mechanisms remain activated until day 60 post infection. The Matlab codes for implementing OLYMPUS, as well as example datasets, are freely accessible via the Web (http://biosignal.med.upatras.gr/wordpress/biosignal/). Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Effects of host cell sterol composition upon internalization of Yersinia pseudotuberculosis and clustered β1 integrin.

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Kim, JiHyun; Fukuto, Hana S; Brown, Deborah A; Bliska, James B; London, Erwin

2018-01-26

Yersinia pseudotuberculosis is a foodborne pathogenic bacterium that causes acute gastrointestinal illness, but its mechanisms of infection are incompletely described. We examined how host cell sterol composition affected Y. pseudotuberculosis uptake. To do this, we depleted or substituted cholesterol in human MDA-MB-231 epithelial cells with various alternative sterols. Decreasing host cell cholesterol significantly reduced pathogen internalization. When host cell cholesterol was substituted with various sterols, only desmosterol and 7-dehydrocholesterol supported internalization. This specificity was not due to sterol dependence of bacterial attachment to host cells, which was similar with all sterols studied. Because a key step in Y. pseudotuberculosis internalization is interaction of the bacterial adhesins invasin and YadA with host cell β1 integrin, we compared the sterol dependence of wildtype Y. pseudotuberculosis internalization with that of Δ inv , Δ yadA , and Δ inv Δ yadA mutant strains. YadA deletion decreased bacterial adherence to host cells, whereas invasin deletion had no effect. Nevertheless, host cell sterol substitution had a similar effect on internalization of these bacterial deletion strains as on the wildtype bacteria. The Δ inv Δ yadA double mutant adhered least to cells and so was not significantly internalized. The sterol structure dependence of Y. pseudotuberculosis internalization differed from that of endocytosis, as monitored using antibody-clustered β1 integrin and previous studies on other proteins, which had a more permissive sterol dependence. This study suggests that agents could be designed to interfere with internalization of Yersinia without disturbing endocytosis. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Host-cell reactivation of uv-irradiated and chemically treated Herpes simplex virus type 1 strain MP in normal and xeroderma pigmentosum skin fibroblasts

International Nuclear Information System (INIS)

Selsky, C.A.

1976-01-01

The host-cell reactivation of UV-irradiated and N-acetoxy-2-acetylaminofluorene-treated herpes simplex virus type 1 strain mp was studied in normal human skin fibroblasts and xeroderma pigmentosum skin fibroblasts from XP genetic complementation groups A-D and in an XP variant. The increasing relative order for the host-cell reactivation of both types of damaged virus in the different complementation groups is A = D < B < C; XP variant = normal controls. XP complementation group D cells, which manifest the most severe inhibition of her ability for both UV-irradiated and N-acetoxy-2-acetylaminofluorene-treated virus, can reactivate nitrogen mustard treated HSV-1 mp to the same extent as normal cells. Together, these results indicate that (1) Excision repair of UV and N-acetoxy-2-acetylaminofluorene DNA damaged viruses share a common rate limiting enzymatic step and (2) The repair defect in xeroderma pigmentosum cells plays little or no role in the recovery of nitrogen mustard treated virus. The results of studies on the effect of caffeine on the survival of both UV- and N-acetoxy-2-acetylaminofluorene-treated virus in normal and XP cells imply that the reactivation of HSV-1 mp is mediated by an excision repair process with little if any recovery contributed by post-replication repair mechanisms. The host-cell reactivation of N-acetoxy-2-acetylaminofluorene-treated HSV-1 mp was also correlated with the defective UV-induced unscheduled DNA synthesis in two skin fibroblast strains established from a skin biopsy obtained from each of two juvenile females who had been clinically diagnosed as xeroderma pigmentosum. These findings are discussed in relation to the further characterization of the xeroderma pigmentosum phenotype and their possible utilization for the selection and isolation of new mammalian cell DNA repair mutants

Synthesis of methyl 3-O-{alpha}-d-glucopyranosyl-C{sub 6}{sup 14}-{beta}-d-xylopyranoside and methyl 2-O-{alpha}-d-Glucopyranosyl-C{sub 6}{sup 14}-l-noviopyranoside; Synthese de methyl-3-O-alpha-D-glucopyranosyl-C{sup 14}-beta-D-xylophranoside et methyl-2-O-alpha-D-glucopyranosyl-C{sub 6}{sup 14}-L-noviopyranoside; Sintez metil-3-O-{alpha}-D-glyukopiranozila-C{sub 6}{sup 14}-{beta}-D-ksilopiranozid i metil 2-O-{alpha}-D-glyukopiranozil-C{sub 6}{sup 14}-L-noviopiranozid; Sintesis de la metil 3-O-{alpha}-D-glucopiranosil-{sup 14}C{sub 6}-{beta}-D-xilopiranosido y de la metil 2-O-{alpha}-D-glucopiranosil-{sup 14}C{sub 6}-L-noviopiranosido

Energy Technology Data Exchange (ETDEWEB)

Barker, S A; Keith, M C; Stacey, M; Stroud, D B.E. [Chemistry Department, University of Birmingham (United Kingdom)

1962-03-15

} + metil {beta}-D-ksilopiranozid Penitsillium lilatsinum/transglyukozilas Metil 3-O-{alpha}-D-glyukopiranozil-C{sub 6}{sup 14}-{beta}-D-ksilopiranozid (I) + glyukoza-C{sub 6}{sup 14} Mal'toza-C{sub 12}{sup 14} + metil L-noviopiranozid Fuzarium moniliform/ transglyukozilas Metsh1-2-O-{alpha}-D-glyukopiranozil-C{sub 6}{sup 14}-L-noviopiranozid (II) + glyukoza-C{sub 6}{sup 14}. Pri takom sinteze predpolagaetsya, chto anomericheskij kharakter glikozidnoj svyazi donorkogo disakharida budet sokhranen v soedinennom disakharide i chto peremeshchennyj ostatok glikozila primknet cherez svoyu vosstanovitel'nuyu gruppu k retseptoru monosakharida glikozida. Pri ispol'zovanii mechennykh C{sup 14} donornogo disakharida ili retseptora glikozida vozmozhen sintez disakharida tol'ko s odnoj iz mechenykh grupp sakhara. Pri sinteze II edinstvennaya gidroksil'naya svobodnaya gruppa v retseptore metilnoviozida nakhoditsya v C{sub 2}, i tol'ko zdes' mozhno prisoedinit' perenosnoj ostatok glikozida. Pri sinteze I metil-ksilozid imeet svobodnyj gidroksil pri C{sub 2}, C{sub 3} i C{sub 4}, a takzhe bylo obnaruzheno peremeshchenie mikrobial'nogo ehnzima v ostatok glikozila osobenno v gidroksil pri C{sub 3}. Struktury I i II byli vyyavleny v rezul'tate analiza ehlementov, opticheskoj rotatsii, infrakrasnogo spektra sovmestno s proverkoj produktov kislotnogo gidroliza i okisleniem periodata. (author)

Quantification of the host response proteome after mammalian reovirus T1L infection.

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Alicia R Berard

Full Text Available All viruses are dependent upon host cells for replication. Infection can induce profound changes within cells, including apoptosis, morphological changes, and activation of signaling pathways. Many of these alterations have been analyzed by gene arrays to measure the cellular "transcriptome." We used SILAC (stable isotope labeling by amino acids in cell culture, combined with high-throughput 2-D HPLC/mass spectrometry, to determine relative quantitative differences in host proteins at 6 and 24 hours after infecting HEK293 cells with reovirus serotype 1 Lang (T1L. 3,076 host proteins were detected at 6 hpi, of which 132 and 68 proteins were significantly up or down regulated, respectively. 2,992 cellular proteins, of which 104 and 49 were up or down regulated, respectively, were identified at 24 hpi. IPA and DAVID analyses indicated proteins involved in cell death, cell growth factors, oxygen transport, cell structure organization and inflammatory defense response to virus were up-regulated, whereas proteins involved in apoptosis, isomerase activity, and metabolism were down-regulated. These proteins and pathways may be suitable targets for intervention to either attenuate virus infection or enhance oncolytic potential.

Contribution of MS-based proteomics to the understanding of Herpes Simplex Virus type 1 interaction with host cells

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Enrique eSantamaría

2012-03-01

Full Text Available Like other DNA viruses, Herpes Simplex Virus type 1 (HSV-1 replicates and proliferates in host cells continuously modulating the host molecular environment. Following a sophisticated temporal expression pattern, HSV-1 encodes at least 89 multifunctional proteins that interplay with and modify the host cell proteome. During the last decade, advances in mass spectrometry applications coupled to the development of proteomic separation methods have allowed to partially monitor the impact of HSV-1 infection in human cells. In this review, we discuss the current use of different proteome fractionation strategies to define HSV-1 targets on two major application areas: i viral protein interactomics to decipher viral protein interactions in host cells and ii differential quantitative proteomics to analyse the virally induced changes in the cellular proteome. Moreover, we will also discuss the potential application of high throughput proteomic approaches to study global proteome dynamics and also post-translational modifications in HSV-1-infected cells, what will greatly improved our molecular knowledge of HSV-1 infection.

Genome-Wide Transposon Mutagenesis Indicates that Mycobacterium marinum Customizes Its Virulence Mechanisms for Survival and Replication in Different Hosts

KAUST Repository

Weerdenburg, Eveline M.; Abdallah, Abdallah; Rangkuti, Farania; Abd El Ghany, Moataz; Otto, Thomas D.; Adroub, Sabir; Molenaar, Douwe; Ummels, Roy; ter Veen, Kars; van Stempvoort, Gunny; van der Sar, Astrid M.; Ali, Shahjahan; Langridge, Gemma C.; Thomson, Nicholas R.; Pain, Arnab; Bitter, Wilbert

2015-01-01

the type VII protein secretion system ESX-1, biosynthesis of polyketide lipids, and utilization of sterols. However, we were also able to show that M. marinum contains an even larger set of host-specific virulence determinants, including proteins involved

Evaluation of renal function using [sup 99m]Tc-MAG3; Comparison with [sup 123]I-OIH and [sup 99m]Tc-DTPA

Energy Technology Data Exchange (ETDEWEB)

Takayama, Teruhiko; Aburano, Tamio; Shuke, Noriyuki (Kanazawa Univ. (Japan). School of Medicine) (and others)

1993-07-01

The utility of [sup 99m]Tc-mercaptoacetyltriglycine (MAG3) was studied clinically. In the renography obtained with [sup 99m]Tc-MAG3, the abdominal aorta and the common iliac arteries were clearly visualized in the vascular phase. Due to less background activity and high target to background ratio, the quality of [sup 99m]Tc-MAG3 image was superior to that of [sup 123]I-OIH or [sup 99m]Tc-DTPA image. The parameters on the renogram including T[sub max], T[sub 2/3], and T[sub 1/2] were compared. The correlation of T[sub max] and T[sub 2/3] or T[sub 1/2] were not significant between [sup 99m]Tc-MAG3 and [sup 123]I-OIH. Another parameter of C[sub 20]/C[sub max], where C[sub 20] and C[sub max] are renal activities at 20 min after injection and at T[sub max] respectively, showed an excellent correlation between [sup 99m]Tc-MAG3 and [sup 123]I-OIH. Using C[sub 20]/C[sub max], pattern of renogram can be characterized numerically. Concerning the relation between C[sub 20]/C[sub max] and renogram pattern, standard renogram pattern showed the C[sub 20]/C[sub max] value of less than 0.4, while hypofunctioning pattern showed more than 0.5. The correlation coefficient between the renal uptake of [sup 99m]Tc-MAG3 and [sup 123]I-OIH was 0.880 with a correlation plot: 'Y=1.16X-0.043', where X and Y represent renal uptake of [sup 99m]Tc-MAG3 and [sup 123]I-OIH, respectively. It can be concluded that [sup 99m]Tc-MAG3 is a useful renal imaging agent as an alternative to [sup 123]I-OIH, in order to evaluate the proximal tubular function and calculate ERPF. (author).

38 CFR 1.602 - Utilization of access.

Science.gov (United States)

2010-07-01

... individual will access only the VBA automated claims records of VA claimants who are represented by the... 1.603, the applicant expressly consents to VBA monitoring the access activities of the applicant at... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Utilization of access. 1...

Vibrational spectroscopic and gravimetric study of some Hofmann-CBA-Type Host and host-guest compounds

International Nuclear Information System (INIS)

Aytekin, M.A.

2005-01-01

In this study, similar to Hofmann type M(C 4 H 7 NH 2 ) 2 Ni(CN) 4 (M=Ni or Co) host and M(C 4 H 7 NH 2 ) 2 Ni(CN) 4 .nG (M=Ni or Co; G=benzene, 1,2-, 1,3-dichlorobenzene; n=the number of guest) hostguest compounds were obtained chemically. The infrared spectra of these compounds were recorded with FT-IR spectrometer in the spectroscopic region of 4000cm-1-400cm-1. From these spectra the vibrational wave numbers of ligand molecule, Ni(CN) 4 2 - ion and guest molecules were determined. The absorption and the liberation processes of the guest molecules in the host compounds were examined at room temperature by gravimetric method. Otherwise, it was seen that the molecular structure was supported by making instrumental analysis of host and some host-guest compounds. By analysing the structures of host and host-guest compounds were found to be similar to those of Hofmann type compounds, ligand molecule cyclobutylamine were coordinated to M metal atom from cyclobutylamine's nitrogen atom, the guest molecules were imprisoned in the structural cavities between the sheets

Temporal and host-related variation in frequencies of genes that enable Phyllotreta nemorum to utilize a novel host plant, Barbarea vulgaris

NARCIS (Netherlands)

Nielsen, J.K.; Jong, de P.W.

2005-01-01

The flea beetle, Phyllotreta nemorum L. (Coleoptera: Chrysomelidae), is an intermediate specialist feeding on a small number of plants within the family Brassicaceae. The most commonly used host plant is Sinapis arvensis L., whereas the species is found more rarely on Cardaria draba (L.) Desv.,

DIVERSITY AND HOST SPECIFICITY OF AZOLLA CYANOBIONTS(1).

Science.gov (United States)

Papaefthimiou, Dimitra; Van Hove, Charles; Lejeune, André; Rasmussen, Ulla; Wilmotte, Annick

2008-02-01

A unique, hereditary symbiosis exists between the water fern Azolla and cyanobacteria that reside within a cavity in the dorsal leaf-lobe of the plant. This association has been studied extensively, and questions have frequently been raised regarding the number and diversity of cyanobionts (cyanobacterial symbionts) among the different Azolla strains and species. In this work, denaturating gradient gel electrophoresis (DGGE) and a clone library based on the 16S rRNA gene were used to study the genetic diversity and host specificity of the cyanobionts in 35 Azolla strains covering a wide taxonomic and geographic range. DNA was extracted directly from the cyanobacterial packets, isolated after enzymatic digestion of the Azolla leaves. Our results indicated the existence of different cyanobiont strains among Azolla species, and diversity within a single Azolla species, independent of the geographic origin of the host. Furthermore, the cyanobiont exhibited host-species specificity and showed most divergence between the two sections of genus Azolla, Azolla and Rhizosperma. These findings are in agreement with the recent redefinition of the taxon Azolla cristata within the section Azolla. With regard to the taxonomic status of the cyanobiont, the genus Anabaena of the Nostocaceae family was identified as the closest relative by this work. © 2008 Phycological Society of America.

Synthesis and structure of the first fullerene complex of titanium Cp{sub 2}Ti({eta}{sup 2}-C{sub 60})

Energy Technology Data Exchange (ETDEWEB)

Burlakov, V.V.; Usatov, A.V.; Lyssenko, K.A.; Antipin, M.Yu.; Novikov, Yu.N.; Shur, V.B. [Russian Academy of Sciences, Moscow (Russian Federation). A.N. Nesmeyanov Inst. of Organoelement Compounds

1999-11-01

The first fullerene complex of titanium Cp{sub 2}Ti({eta}{sup 2}-C{sub 60}) has been synthesized by reaction of the bis(trimethylsilyl)-acetylene complex of titanocene Cp{sub 2}Ti({eta}{sup 2}-Me{sub 3}SiC{sub 2}SiMe{sub 3}) with an equimolar amount of fullerene-60 in toluene at room temperature under argon. An X-ray diffraction study of the complex has shown that it has the structure of a titanacyclopropane derivative. (orig.)

HIV-1 evolution, drug resistance, and host genetics: The Indian scenario

Directory of Open Access Journals (Sweden)

U Shankarkumar

2009-03-01

Full Text Available U Shankarkumar, A Pawar, K GhoshNational Institute of Immunohaematology (ICMR, KEM Hospital, Parel, Mumbai, Maharashtra, IndiaAbstract: A regimen with varied side effects and compliance is of paramount importance to prevent viral drug resistance. Most of the drug-resistance studies, as well as interpretation algorithms, are based on sequence data from HIV-1 subtype B viruses. Increased resistance to antiretroviral drugs leads to poor prognosis by restricting treatment options. Due to suboptimal adherence to antiretroviral therapy there is an emergence of drug-resistant HIV-1 strains. The other factors responsible for this viral evolution are antiretroviral drug types and host genetics, especially major histocompatibility complex (MHC. Both primary and secondary drug resistances occur due to mutations in specific epitopes of viral protein regions which may influence the T cell recognition by immune system through MHC Class I and class II alleles. Mutations in viral epitopes enable the virus to escape the immune system. New drugs under clinical trials are being added but their exorbitant costs limit their access in developing countries. Thus the environmental consequences and, the impact of both viral and host genetic variations on the therapy in persons infected with HIV-1 clade C from India need to be determined.Keywords: HIV-1 C drug resistance, virus adaptation, HARRT, India

Genome-wide CRISPR/Cas9 Screen Identifies Host Factors Essential for Influenza Virus Replication

Directory of Open Access Journals (Sweden)

Julianna Han

2018-04-01

Full Text Available Summary: The emergence of influenza A viruses (IAVs from zoonotic reservoirs poses a great threat to human health. As seasonal vaccines are ineffective against zoonotic strains, and newly transmitted viruses can quickly acquire drug resistance, there remains a need for host-directed therapeutics against IAVs. Here, we performed a genome-scale CRISPR/Cas9 knockout screen in human lung epithelial cells with a human isolate of an avian H5N1 strain. Several genes involved in sialic acid biosynthesis and related glycosylation pathways were highly enriched post-H5N1 selection, including SLC35A1, a sialic acid transporter essential for IAV receptor expression and thus viral entry. Importantly, we have identified capicua (CIC as a negative regulator of cell-intrinsic immunity, as loss of CIC resulted in heightened antiviral responses and restricted replication of multiple viruses. Therefore, our study demonstrates that the CRISPR/Cas9 system can be utilized for the discovery of host factors critical for the replication of intracellular pathogens. : Using a genome-wide CRISPR/Cas9 screen, Han et al. demonstrate that the major hit, the sialic acid transporter SLC35A1, is an essential host factor for IAV entry. In addition, they identify the DNA-binding transcriptional repressor CIC as a negative regulator of cell-intrinsic immunity. Keywords: CRISPR/Cas9 screen, GeCKO, influenza virus, host factors, sialic acid pathway, SLC35A1, Capicua, CIC, cell-intrinsic immunity, H5N1

Adenovirus E4ORF1-induced MYC activation promotes host cell anabolic glucose metabolism and virus replication.

Science.gov (United States)

Thai, Minh; Graham, Nicholas A; Braas, Daniel; Nehil, Michael; Komisopoulou, Evangelia; Kurdistani, Siavash K; McCormick, Frank; Graeber, Thomas G; Christofk, Heather R

2014-04-01

Virus infections trigger metabolic changes in host cells that support the bioenergetic and biosynthetic demands of viral replication. Although recent studies have characterized virus-induced changes in host cell metabolism (Munger et al., 2008; Terry et al., 2012), the molecular mechanisms by which viruses reprogram cellular metabolism have remained elusive. Here, we show that the gene product of adenovirus E4ORF1 is necessary for adenovirus-induced upregulation of host cell glucose metabolism and sufficient to promote enhanced glycolysis in cultured epithelial cells by activation of MYC. E4ORF1 localizes to the nucleus, binds to MYC, and enhances MYC binding to glycolytic target genes, resulting in elevated expression of specific glycolytic enzymes. E4ORF1 activation of MYC promotes increased nucleotide biosynthesis from glucose intermediates and enables optimal adenovirus replication in primary lung epithelial cells. Our findings show how a viral protein exploits host cell machinery to reprogram cellular metabolism and promote optimal progeny virion generation. Copyright © 2014 Elsevier Inc. All rights reserved.

Glucosinolates from Host Plants Influence Growth of the Parasitic Plant Cuscuta gronovii and Its Susceptibility to Aphid Feeding1[OPEN

Science.gov (United States)

2016-01-01

Parasitic plants acquire diverse secondary metabolites from their hosts, including defense compounds that target insect herbivores. However, the ecological implications of this phenomenon, including the potential enhancement of parasite defenses, remain largely unexplored. We studied the translocation of glucosinolates from the brassicaceous host plant Arabidopsis (Arabidopsis thaliana) into parasitic dodder vines (Convolvulaceae; Cuscuta gronovii) and its effects on the parasite itself and on dodder-aphid interactions. Aliphatic and indole glucosinolates reached concentrations in parasite tissues higher than those observed in corresponding host tissues. Dodder growth was enhanced on cyp79B2 cyp79B3 hosts (without indole glucosinolates) but inhibited on atr1D hosts (with elevated indole glucosinolates) relative to wild-type hosts, which responded to parasitism with localized elevation of indole and aliphatic glucosinolates. These findings implicate indole glucosinolates in defense against parasitic plants. Rates of settling and survival on dodder vines by pea aphids (Acyrthosiphon pisum) were reduced significantly when dodder parasitized glucosinolate-producing hosts (wild type and atr1D) compared with glucosinolate-free hosts (cyp79B2 cyp79B3 myb28 myb29). However, settling and survival of green peach aphids (Myzus persicae) were not affected. M. persicae population growth was actually reduced on dodder parasitizing glucosinolate-free hosts compared with wild-type or atr1D hosts, even though stems of the former contain less glucosinolates and more amino acids. Strikingly, this effect was reversed when the aphids fed directly upon Arabidopsis, which indicates an interactive effect of parasite and host genotype on M. persicae that stems from host effects on dodder. Thus, our findings indicate that glucosinolates may have both direct and indirect effects on dodder-feeding herbivores. PMID:27482077

Energy-cascade organic photovoltaic devices incorporating a host-guest architecture.

Science.gov (United States)

Menke, S Matthew; Holmes, Russell J

2015-02-04

In planar heterojunction organic photovoltaic devices (OPVs), broad spectral coverage can be realized by incorporating multiple molecular absorbers in an energy-cascade architecture. Here, this approach is combined with a host-guest donor layer architecture previously shown to optimize exciton transport for the fluorescent organic semiconductor boron subphthalocyanine chloride (SubPc) when diluted in an optically transparent host. In order to maximize the absorption efficiency, energy-cascade OPVs that utilize both photoactive host and guest donor materials are examined using the pairing of SubPc and boron subnaphthalocyanine chloride (SubNc), respectively. In a planar heterojunction architecture, excitons generated on the SubPc host rapidly energy transfer to the SubNc guest, where they may migrate toward the dissociating, donor-acceptor interface. Overall, the incorporation of a photoactive host leads to a 13% enhancement in the short-circuit current density and a 20% enhancement in the power conversion efficiency relative to an optimized host-guest OPV combining SubNc with a nonabsorbing host. This work underscores the potential for further design refinements in planar heterojunction OPVs and demonstrates progress toward the effective separation of functionality between constituent OPV materials.

MODERATE-LUMINOSITY GROWING BLACK HOLES FROM 1.25 < z < 2.7: VARIED ACCRETION IN DISK-DOMINATED HOSTS

Energy Technology Data Exchange (ETDEWEB)

Simmons, B. D.; Glikman, E. [Astronomy Department, Yale University, New Haven, CT 06511 (United States); Urry, C. M.; Schawinski, K. [Yale Center for Astronomy and Astrophysics, Physics Department, Yale University, New Haven, CT 06511 (United States); Cardamone, C., E-mail: brooke.simmons@astro.ox.ac.uk [Sheridan Center for Teaching and Learning, Brown University, 96 Waterman St., Providence RI 02912 (United States)

2012-12-10

We compute black hole masses and bolometric luminosities for 57 active galactic nuclei (AGNs) in the redshift range 1.25 {<=} z {<=} 2.67, selected from the GOODS-South deep multi-wavelength survey field via their X-ray emission. We determine host galaxy morphological parameters by separating the galaxies from their central point sources in deep Hubble Space Telescope images, and host stellar masses and colors by multi-wavelength spectral energy distribution fitting. Of GOODS AGNs at these redshifts, 90% have detected rest-frame optical nuclear point sources; bolometric luminosities range from 2 Multiplication-Sign 10{sup 43} to 2 Multiplication-Sign 10{sup 46} erg s{sup -1}. The black holes are growing at a range of accretion rates, with {approx}> 50% of the sample having L/L{sub Edd} < 0.1. Of the host galaxies, 70% have stellar masses M{sub *} > 10{sup 10} M{sub Sun }, with a range of colors suggesting a complex star formation history. We find no evolution of AGN bolometric luminosity within the sample, and no correlation between AGN bolometric luminosity and host stellar mass, color, or morphology. Fully half the sample of host galaxies are disk-dominated, with another 25% having strong disk components. Fewer than 15% of the systems appear to be at some stage of a major merger. These moderate-luminosity AGN hosts are therefore inconsistent with a dynamical history dominated by mergers strong enough to destroy disks, indicating that minor mergers or secular processes dominate the coevolution of galaxies and their central black holes at z {approx} 2.

The influenza fingerprints: NS1 and M1 proteins contribute to specific host cell ultrastructure signatures upon infection by different influenza A viruses

Energy Technology Data Exchange (ETDEWEB)

Terrier, Olivier; Moules, Vincent; Carron, Coralie; Cartet, Gaeelle [Equipe VirCell, Laboratoire de Virologie et Pathologie Humaine, VirPath EMR 4610, Universite de Lyon, Universite Claude Bernard Lyon 1, Hospices Civils de Lyon, Faculte de medecine RTH Laennec, rue Guillaume Paradin, F-69008 Lyon (France); Frobert, Emilie [Laboratoire de Virologie, Centre de Biologie et de Pathologie Est, Hospices Civils de Lyon, 59 boulevard Pinel, F-69677 Bron Cedex, Lyon (France); Yver, Matthieu; Traversier, Aurelien [Equipe VirCell, Laboratoire de Virologie et Pathologie Humaine, VirPath EMR 4610, Universite de Lyon, Universite Claude Bernard Lyon 1, Hospices Civils de Lyon, Faculte de medecine RTH Laennec, rue Guillaume Paradin, F-69008 Lyon (France); Wolff, Thorsten [Division of Influenza/Respiratory Viruses, Robert Koch Institute, Nordufer 20, D-13353 Berlin (Germany); Riteau, Beatrice [Laboratoire de Virologie et Pathologie Humaine, VirPath EMR 4610, Universite de Lyon, Universite Claude Bernard Lyon 1, Hospices Civils de Lyon, Faculte de medecine RTH Laennec, rue Guillaume Paradin, F-69008 Lyon (France); Naffakh, Nadia [Institut Pasteur, Unite de Genetique Moleculaire des Virus Respiratoires, URA CNRS 3015, EA302 Universite Paris Diderot, Paris (France); and others

2012-10-10

Influenza A are nuclear replicating viruses which hijack host machineries in order to achieve optimal infection. Numerous functional virus-host interactions have now been characterized, but little information has been gathered concerning their link to the virally induced remodeling of the host cellular architecture. In this study, we infected cells with several human and avian influenza viruses and we have analyzed their ultrastructural modifications by using electron and confocal microscopy. We discovered that infections lead to a major and systematic disruption of nucleoli and the formation of a large number of diverse viral structures showing specificity that depended on the subtype origin and genomic composition of viruses. We identified NS1 and M1 proteins as the main actors in the remodeling of the host ultra-structure and our results suggest that each influenza A virus strain could be associated with a specific cellular fingerprint, possibly correlated to the functional properties of their viral components.

The influenza fingerprints: NS1 and M1 proteins contribute to specific host cell ultrastructure signatures upon infection by different influenza A viruses

International Nuclear Information System (INIS)

Terrier, Olivier; Moules, Vincent; Carron, Coralie; Cartet, Gaëlle; Frobert, Emilie; Yver, Matthieu; Traversier, Aurelien; Wolff, Thorsten; Riteau, Beatrice; Naffakh, Nadia

2012-01-01

Influenza A are nuclear replicating viruses which hijack host machineries in order to achieve optimal infection. Numerous functional virus–host interactions have now been characterized, but little information has been gathered concerning their link to the virally induced remodeling of the host cellular architecture. In this study, we infected cells with several human and avian influenza viruses and we have analyzed their ultrastructural modifications by using electron and confocal microscopy. We discovered that infections lead to a major and systematic disruption of nucleoli and the formation of a large number of diverse viral structures showing specificity that depended on the subtype origin and genomic composition of viruses. We identified NS1 and M1 proteins as the main actors in the remodeling of the host ultra-structure and our results suggest that each influenza A virus strain could be associated with a specific cellular fingerprint, possibly correlated to the functional properties of their viral components.

Frequent conjugative transfer accelerates adaptation of a broad-host-range plasmid to an unfavorable Pseudomonas putida host.

Science.gov (United States)

Heuer, Holger; Fox, Randal E; Top, Eva M

2007-03-01

IncP-1 plasmids are known to be promiscuous, but it is not understood if they are equally well adapted to various species within their host range. Moreover, little is known about their fate in bacterial communities. We determined if the IncP-1beta plasmid pB10 was unstable in some Proteobacteria, and whether plasmid stability was enhanced after long-term carriage in a single host and when regularly switched between isogenic hosts. Plasmid pB10 was found to be very unstable in Pseudomonas putida H2, and conferred a high cost (c. 20% decrease in fitness relative to the plasmid-free host). H2(pB10) was then evolved under conditions that selected for plasmid maintenance, with or without regular plasmid transfer (host-switching). When tested in the ancestral host, the evolved plasmids were more stable and their cost was significantly reduced (9% and 16% for plasmids from host-switched and nonswitched lineages, respectively). Our findings suggest that IncP-1 plasmids can rapidly adapt to an unfavorable host by improving their overall stability, and that regular conjugative transfer accelerates this process.

Study of infrared emission spectroscopy for the B{sup 1}Δ{sub g}–A{sup 1}Π{sub u} and B{sup ′1}Σ{sub g}{sup +}–A{sup 1}Π{sub u} systems of C{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Chen, Wang, E-mail: sc19321@s.okayama-u.ac.jp, E-mail: okakent@okayama-u.ac.jp, E-mail: pbernath@odu.edu; Kawaguchi, Kentarou, E-mail: sc19321@s.okayama-u.ac.jp, E-mail: okakent@okayama-u.ac.jp, E-mail: pbernath@odu.edu; Tang, Jian, E-mail: jtang@okayama-u.ac.jp [Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, 700-8530, Okayama (Japan); Bernath, Peter F., E-mail: sc19321@s.okayama-u.ac.jp, E-mail: okakent@okayama-u.ac.jp, E-mail: pbernath@odu.edu [Department of Chemistry and Biochemistry, Old Dominion University, 4541 Hampton Boulevard, Norfolk, Virginia 23529-0126 (United States)

2016-02-14

Thirteen bands for the B{sup 1}Δ{sub g}–A{sup 1}Π{sub u} system and eleven bands for the B{sup ′1}Σ{sub g}{sup +}–A{sup 1}Π{sub u} system of C{sub 2} were identified in the Fourier transform infrared emission spectra of hydrocarbon discharges. The B{sup ′1}Σ{sub g}{sup +} v = 4 and the B{sup 1}Δ{sub g} v = 6, 7, and 8 vibrational levels involved in nine bands were studied for the first time. A direct global analysis with Dunham parameters was carried out satisfactorily for the B{sup 1}Δ{sub g}–A{sup 1}Π{sub u} system except for a small perturbation in the B{sup 1}Δ{sub g} v = 6 level. The calculated rovibrational term energies up to B{sup 1}Δ{sub g} v = 12 showed that the level crossing between the B{sup 1}Δ{sub g} and d{sup 3}Π{sub g} states is responsible for many of the prominent perturbations in the Swan system observed previously. Nineteen forbidden transitions of the B{sup 1}Δ{sub g}–a{sup 3}Π{sub u} transition were identified and the off-diagonal spin-orbit interaction constant A{sub dB} between d{sup 3}Π{sub g} and B{sup 1}Δ{sub g} was derived as 8.3(1) cm{sup −1}. For the B{sup ′1}Σ{sub g}{sup +}–A{sup 1}Π{sub u} system, only individual band analyses for each vibrational level in the B′{sup 1}Σ{sub g}{sup +} state could be done satisfactorily and Dunham parameters obtained from these effective parameters showed that the anharmonic vibrational constant ω{sub e}x{sub e} is anomalously small (nearly zero). Inspection of the RKR (Rydberg-Klein-Rees) potential curves for the B{sup ′1}Σ{sub g}{sup +} and X{sup 1}Σ{sub g}{sup +} states revealed that an avoided crossing or nearly avoided crossing may occur around 30 000 cm{sup −1}, which is responsible for the anomalous molecular constants in these two states.

Carbon translocation from symbiont to host depends on irradiance and food availability in the tropical coral Stylophora pistillata

Science.gov (United States)

Tremblay, P.; Grover, R.; Maguer, J. F.; Hoogenboom, M.; Ferrier-Pagès, C.

2014-03-01

Reef-building corals live in symbiosis with dinoflagellates that translocate a large proportion of their photosynthetically fixed carbon compounds to their coral host for its own metabolism. The carbon budget and translocation rate, however, vary depending on environmental conditions, coral host species, and symbiont clade. To quantify variability in carbon translocation in response to environmental conditions, this study assessed the effect of two different irradiance levels (120 and 250 μmol photons m-2 s-1) and feeding regimes (fed with Artemia salina nauplii and unfed) on the carbon budget of the tropical coral Stylophora pistillata. For this purpose, H13CO3 --enriched seawater was used to trace the conversion of photosynthetic carbon into symbiont and coral biomass and excrete particulate organic carbon. Results showed that carbon translocation (ca. 78 %) and utilization were similar under both irradiance levels for unfed colonies. In contrast, carbon utilization by fed colonies was dependent on the growth irradiance. Under low irradiance, heterotrophy was accompanied by lower carbon translocation (71 %), higher host and symbiont biomass, and higher calcification rates. Under high irradiance, heterotrophy was accompanied by higher rates of photosynthesis, respiration, and carbon translocation (90 %) as well as higher host biomass. Hence, levels of resource sharing within coral-dinoflagellate symbioses depend critically on environmental conditions.

The Role of Interleukin-1 Family Members in the Host Defence Against Aspergillus fumigatus

NARCIS (Netherlands)

Gresnigt, M.S.; Veerdonk, F.L. van de

2014-01-01

The interleukin (IL)-1 family consists of 11 members, which all play significant roles in regulating inflammatory responses in the host. IL-1alpha and IL-1beta exert potent pro-inflammatory effects and are key players in the recruitment of neutrophils to the site of inflammation. Protective

Large-scale gene expression reveals different adaptations of Hyalopterus persikonus to winter and summer host plants.

Science.gov (United States)

Cui, Na; Yang, Peng-Cheng; Guo, Kun; Kang, Le; Cui, Feng

2017-06-01

Host alternation, an obligatory seasonal shifting between host plants of distant genetic relationship, has had significant consequences for the diversification and success of the superfamily of aphids. However, the underlying molecular mechanism remains unclear. In this study, the molecular mechanism of host alternation was explored through a large-scale gene expression analysis of the mealy aphid Hyalopterus persikonus on winter and summer host plants. More than four times as many unigenes of the mealy aphid were significantly upregulated on summer host Phragmites australis than on winter host Rosaceae plants. In order to identify gene candidates related to host alternation, the differentially expressed unigenes of H. persikonus were compared to salivary gland expressed genes and secretome of Acyrthosiphon pisum. Genes involved in ribosome and oxidative phosphorylation and with molecular functions of heme-copper terminal oxidase activity, hydrolase activity and ribosome binding were potentially upregulated in salivary glands of H. persikonus on the summer host. Putative secretory proteins, such as detoxification enzymes (carboxylesterases and cytochrome P450s), antioxidant enzymes (peroxidase and superoxide dismutase), glutathione peroxidase, glucose dehydrogenase, angiotensin-converting enzyme, cadherin, and calreticulin, were highly expressed in H. persikonus on the summer host, while a SCP GAPR-1-like family protein and a salivary sheath protein were highly expressed in the aphids on winter hosts. These results shed light on phenotypic plasticity in host utilization and seasonal adaptation of aphids. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Theoretical estimates of the anapole magnetizabilities of C{sub 4}H{sub 4}X{sub 2} cyclic molecules for X=O, S, Se, and Te

Energy Technology Data Exchange (ETDEWEB)

Pagola, G. I.; Ferraro, M. B. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, and IFIBA, CONICET, Universidad de Buenos Aires, Ciudad Universitaria, Pab. I, (1428) Buenos Aires (Argentina); Provasi, P. F. [Departamento de Física, Northeastern University, Av. Libertad 5500, W3400 AAS, Corrientes (Argentina); Pelloni, S.; Lazzeretti, P., E-mail: lazzeret@unimo.it [Dipartimento di Chimica, Università degli Studi di Modena e Reggio Emilia, via G. Campi 183, 41100 Modena (Italy)

2014-09-07

Calculations have been carried out for C{sub 4}H{sub 4}X{sub 2} cyclic molecules, with X=O, S, Se, and Te, characterized by the presence of magnetic-field induced toroidal electron currents and associated orbital anapole moments. The orbital anapole induced by a static nonuniform magnetic field B, with uniform curl C=∇×B, is rationalized via a second-rank anapole magnetizability tensor a{sub αβ}, defined as minus the second derivative of the second-order interaction energy with respect to the components C{sub α} and B{sub β}. The average anapole magnetizability a{sup ¯} equals −χ{sup ¯}, the pseudoscalar obtained by spatial averaging of the dipole-quadrupole magnetizability χ{sub α,βγ}. It has different sign for D and L enantiomeric systems and can therefore be used for chiral discrimination. Therefore, in an isotropic chiral medium, a homogeneous magnetic field induces an electronic anapole A{sub α}, having the same magnitude, but opposite sign, for two enantiomorphs.

Stability of zinc phthalocyanine and fullerene C{sub 60} organic solar cells

Energy Technology Data Exchange (ETDEWEB)

Lessmann, Rudolf

2010-05-10

heterojunction in a Metal-Insulator-p-Semiconductor (m-i-p) configuration. Variations of the FHJ and of the m-i-p structures are also used to verify the limits of the stability of electrically p- and n- doped organic semiconducting layers. The least stable solar cells are the FHJ devices. These devices show a fast initial decrease of all their characteristic conversion parameters but the Voc. After a few hundred hours, the saturation current (current under a reverse bias of 1 V) was almost stable. The saturation current is related to the number of absorbing centers, the decrease indicates that the degradation of the absorbing centers has stopped. With wavelength resolved external quantum efficiency measurements and chemical analysis, it was found that the degradation is related to the oxidation of C{sub 60}. It was also shown that the use of organic dopants do not significantly affect the lifetime. The results show that the m-i-p solar cells are more stable than the FHJ devices. They are also stable under high temperatures up to 105 C. Outdoor testing also showed that the solar cells remained chemically, electrically and mechanically stable during a 900 h test. (orig.)

Herpes simplex virus types 1 and 2 induce shutoff of host protein synthesis by different mechanisms in Friend erythroleukemia cells

International Nuclear Information System (INIS)

Hill, T.M.; Sinden, R.R.; Sadler, J.R.

1983-01-01

Herpes simplex virus type 1 (HSV-1) and HSV-2 disrupt host protein synthesis after viral infection. We have treated both viral types with agents which prevent transcription of the viral genome and used these treated viruses to infect induced Friend erythroleukemia cells. By measuring the changes in globin synthesis after infection, we have determined whether expression of the viral genome precedes the shutoff of host protein synthesis or whether the inhibitor molecule enters the cells as part of the virion. HSV-2-induced shutoff of host protein synthesis was insensitive to the effects of shortwave (254-nm) UV light and actinomycin D. Both of the treatments inhibited HSV-1-induced host protein shutoff. Likewise, treatment of HSV-1 with the cross-linking agent 4,5',8-trimethylpsoralen and longwave (360-nm) UV light prevented HSV-1 from inhibiting cellular protein synthesis. Treatment of HSV-2 with 4,5',8-trimethylpsoralen did not affect the ability of the virus to interfere with host protein synthesis, except at the highest doses of longwave UV light. It was determined that the highest longwave UV dosage damaged the HSV-2 virion as well as cross-linking the viral DNA. The results suggest that HSV-2 uses a virion-associated component to inhibit host protein synthesis and that HSV-1 requires the expression of the viral genome to cause cellular protein synthesis shutoff

Synthesis, structural approach and electronic properties of V{sub 18}O{sub 45}, (N{sub 2}C{sub 6}H{sub 14}){sub 6}: a new organically templated vanadium oxide exhibiting V{sub 2}O{sub 5} layer topology

Energy Technology Data Exchange (ETDEWEB)

Sicard, M.; Maignan, A. [Laboratoire Crismat-ISMRa UMR 6508, 14 - Caen (France); Riou, D. [Universite de Versailles St Quentin, Institut Lavoisier UMR CNRS 8637, 78 - Versailles (France)

2002-02-01

V{sub 18}O{sub 45}, (N{sub 2}C{sub 6}H{sub 14}){sub 6} was hydrothermally synthesized in the form of thin platelets. Its structural approach was investigated by single crystal X-ray diffraction (non-centrosymmetric P2{sub 1} (No 4) monoclinic space group with a 10.7713(3) Angstrom, b = 11.2697(3) Angstrom, c = 29.7630(9) Angstrom, {beta} = 93.924(1) deg., V = 3604.4(2) Angstrom{sup 3}, Z = 2). V{sub 18}O{sub 45}, (N{sub 2}C{sub 6}H{sub 14}){sub 6} exhibits a lamellar structure built up from the stacking of vanadium oxide slabs between which the di-protonated 1,4-di-aza-bi-cyclo[2.2.2]octane organic cations are intercalated. The oxide layers are topologically similar to those encountered in the parent vanadium penta-oxide V{sub 2}O{sub 5} but exhibiting here a mixed valence V{sup IV}/V{sup V} with a ratio equal to 2. The electronic conductivity measurements performed on the crystals show that the resistivity curves are described by an Arrhenius law with an activation energy of 0.16 eV. (authors)

Study of the contact charge transfer behavior between cryptophanes (A and E) and fullerene by absorption, fluorescence and {sup 1}H NMR spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Zhang Caihong; Shen Weili; Fan Ruying; Zhang Guomei; Shangguan Lingzhi; Chao Jianbin; Shuang Shaomin [Research Center of Environmental Science and Engineering, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006 (China); Dong Chuan, E-mail: dc@sxu.edu.cn [Research Center of Environmental Science and Engineering, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006 (China); Choi, Martin M.F., E-mail: mfchoi@hkbu.edu.hk [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong (Hong Kong)

2009-09-14

A group of novel cage-like compounds cryptophanes A and E were synthesized from vanillin by a three-step method. The intermolecular interaction between cryptophanes (A and E) and fullerene (C{sub 60}) was investigated in detail by absorption, fluorescence and {sup 1}H NMR spectroscopy. The absorption of C{sub 60} at 410-650 nm decreased in the presence of cryptophanes A or E. The decrease in absorption intensity was proportional to the concentration of cryptophanes A or E. On the other hand, the fluorescence intensity of cryptophanes A or E decreased and the emission maxima were blue-shifted with the increase in C{sub 60} concentration. These results suggest that contact charge transfer (CCT) complexes can be formed from C{sub 60} with cryptophanes A or E. In addition, the electrochemical behavior of cryptophanes (A and E) and C{sub 60} was studied by cyclic voltammetry. The redox currents of cryptophanes (A and E) decreased and the peak potentials were shifted on addition of C{sub 60}. The changes in the chemical shifts ({Delta}{delta}) of aromatic protons of cryptophanes (A and E) in their NMR spectra further support that CCT complexes were formed with cryptophanes as the electron donors and C{sub 60} as the electron acceptor.

Evaluation of integrals involving powers of (1-x2) and two associated Legendre functions or Gegenbauer polynomials

International Nuclear Information System (INIS)

Rashid, M.A.

1984-08-01

Integrals involving powers of (1-x 2 ) and two associated Legendre functions or two Gegenbauer polynomials are evaluated as finite sums which can be expressed in terms of terminating hypergeometric function 4 F 3 . The integrals which are evaluated are ∫sub(-1)sup(1)[Psub(l)sup(m)(x)Psub(k)sup(n)(x)]/[(1-x 2 )sup(p+1)]dx and ∫sub(-1)sup(1)Csub(l)sup(α)(x)Csub(k)sup(β)(x)[(1-x 2 )sup[(α+β-3)/2-p

Novel approach for identification of influenza virus host range and zoonotic transmissible sequences by determination of host-related associative positions in viral genome segments.

Science.gov (United States)

Kargarfard, Fatemeh; Sami, Ashkan; Mohammadi-Dehcheshmeh, Manijeh; Ebrahimie, Esmaeil

2016-11-16

Recent (2013 and 2009) zoonotic transmission of avian or porcine influenza to humans highlights an increase in host range by evading species barriers. Gene reassortment or antigenic shift between viruses from two or more hosts can generate a new life-threatening virus when the new shuffled virus is no longer recognized by antibodies existing within human populations. There is no large scale study to help understand the underlying mechanisms of host transmission. Furthermore, there is no clear understanding of how different segments of the influenza genome contribute in the final determination of host range. To obtain insight into the rules underpinning host range determination, various supervised machine learning algorithms were employed to mine reassortment changes in different viral segments in a range of hosts. Our multi-host dataset contained whole segments of 674 influenza strains organized into three host categories: avian, human, and swine. Some of the sequences were assigned to multiple hosts. In point of fact, the datasets are a form of multi-labeled dataset and we utilized a multi-label learning method to identify discriminative sequence sites. Then algorithms such as CBA, Ripper, and decision tree were applied to extract informative and descriptive association rules for each viral protein segment. We found informative rules in all segments that are common within the same host class but varied between different hosts. For example, for infection of an avian host, HA14V and NS1230S were the most important discriminative and combinatorial positions. Host range identification is facilitated by high support combined rules in this study. Our major goal was to detect discriminative genomic positions that were able to identify multi host viruses, because such viruses are likely to cause pandemic or disastrous epidemics.

Synthesis of [1-.sup.13C]pyruvic acid], [2-.sup.13C]pyruvic acid], [3-.sup.13C]pyruvic acid] and combinations thereof

Energy Technology Data Exchange (ETDEWEB)

Martinez, Rodolfo A. (Santa Fe, NM), Unkefer; Clifford J. (Los Alamos, NM), Alvarez; Marc, A [Santa Fe, NM

2012-06-12

The present invention is directed to the labeled compounds, ##STR00001## wherein C* is each either .sup.13C and .sup.12C where at least one C* is .sup.13C, each hydrogen of the methylene group is hydrogen or deuterium, the methyl group includes either zero or three deuterium atoms, Q is sulfide, sulfinyl, or sulfone, Z is an aryl group such as 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, or a phenyl group ##STR00002## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently either hydrogen, a C.sub.1-C.sub.4 lower alkyl, a halogen, and an amino group such as NH.sub.2, NHR and NRR' where R and R' are each independently either a C.sub.1-C.sub.4 lower alkyl, a phenyl, and an alkoxy group, and the methyl group can include either zero or three deuterium atoms. The present invention is also directed to the labeled compounds ##STR00003##

Bst1 is required for Candida albicans infecting host via facilitating cell wall anchorage of Glycosylphosphatidyl inositol anchored proteins

Science.gov (United States)

Liu, Wei; Zou, Zui; Huang, Xin; Shen, Hui; He, Li Juan; Chen, Si Min; Li, Li Ping; Yan, Lan; Zhang, Shi Qun; Zhang, Jun Dong; Xu, Zheng; Xu, Guo Tong; An, Mao Mao; Jiang, Yuan Ying

2016-01-01

Glycosylphosphatidyl inositol anchored proteins (GPI-APs) on fungal cell wall are essential for invasive infections. While the function of inositol deacylation of GPI-APs in mammalian cells has been previously characterized the impact of inositol deacylation in fungi and implications to host infection remains largely unexplored. Herein we describe our identification of BST1, an inositol deacylase of GPI-Aps in Candida albicans, was critical for GPI-APs cell wall attachment and host infection. BST1-deficient C. albicans (bst1Δ/Δ) was associated with severely impaired cell wall anchorage of GPI-APs and subsequen unmasked β-(1,3)-glucan. Consistent with the aberrant cell wall structures, bst1Δ/Δ strain did not display an invasive ability and could be recognized more efficiently by host immune systems. Moreover, BST1 null mutants or those expressing Bst1 variants did not display inositol deacylation activity and exhibited severely attenuated virulence and reduced organic colonization in a murine systemic candidiasis model. Thus, Bst1 can facilitate cell wall anchorage of GPI-APs in C. albicans by inositol deacylation, and is critical for host invasion and immune escape. PMID:27708385

Host genetics affect microbial ecosystems via host immunity.

Science.gov (United States)

El Kafsi, Hela; Gorochov, Guy; Larsen, Martin

2016-10-01

Genetic evolution of multicellular organisms has occurred in response to environmental challenges, including competition for nutrients, climate change, physical and chemical stressors, and pathogens. However, fitness of an organism is dependent not only on defense efficacy, but also on the ability to take advantage of symbiotic organisms. Indeed, microbes not only encompass pathogenicity, but also enable efficient nutrient uptake from diets nondegradable by the host itself. Moreover, microbes play important roles in the development of host immunity. Here we review associations between specific host genes and variance in microbiota composition and compare with interactions between microbes and host immunity. Recent genome-wide association studies reveal that symbiosis between host and microbiota is the exquisite result of genetic coevolution. Moreover, a subset of microbes from human and mouse microbiota have been identified to interact with humoral and cellular immunity. Interestingly, microbes associated with both host genetics and host immunity are taxonomically related. Most involved are Bifidobacterium, Lactobacillus, and Akkermansia, which are dually associated with both host immunity and host genetics. We conclude that future therapeutics targeting microbiota in the context of chronic inflammatory diseases need to consider both immune and genetic host features associated with microbiota homeostasis.

The host galaxy of GRB 990712

DEFF Research Database (Denmark)

Christensen, L.; Hjorth, J.; Gorosabel, J.

2004-01-01

We present a comprehensive study of the z = 0.43 host galaxy of GRB 990712, involving ground-based photometry, spectroscopy, and HST imaging. The broad-band UBVRIJHKs photometry is used to determine the global spectral energy distribution (SED) of the host galaxy. Comparison with that of known...... galaxy types shows that the host is similar to a moderately kreddened starburst galaxy with a young stellar population. The estimated internal extinction in the host is A(V) = 0.15 +/- 0.1 and the star-formation rate (SFR) from the UV continuum is 1.3 +/- 0.3 M-circle dot yr(-1) (not corrected...... for the effects of extinction). Other galaxy template spectra than starbursts failed to reproduce the observed SED. We also present VLT spectra leading to the detection of Halpha from the GRB host galaxy. A SFR of 2.8 +/- 0.7 M-circle dot yr(-1) is inferred from the Halpha line flux, and the presence of a young...

Synthesis of C{sub 60}(OH){sub 18-20} in aqueous alkaline solution under O{sub 2}-atmosphere

Energy Technology Data Exchange (ETDEWEB)

Alves, Gustavo Catao; Ladeira, Luiz Orlando; Righi, Ariete; Krambrock, Klaus; Pinheiro, Mauricio Veloso B. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Fisica; Calado, Hallen Daniel; Gil, Rossimiriam Pereira de Freitas [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica]. E-mail: gustavo.catao@terra.com.br

2006-09-15

In this work we report on an alternative synthesis of water-soluble fullerenes known as fullerols, aiming for biomedical applications. The synthesis is based on a process in which polyethylene glycol (PEG400) is used as phase-transfer catalyst between fullerene/benzene and aqueous NaOH solutions. The polyhydroxylation of the fullerenes occurs in the NaOH solution under a continuous flow of O{sub 2} to enhance the reaction yield. The resulting compound was characterized with infrared spectroscopy, nuclear magnetic resonance, thermo-gravimetric analysis and optical absorption. The formation of C{sub 60}(OH){sub 18-20} in high yields was confirmed. (author)

Microscale fracture mechanisms of a Cr{sub 3}C{sub 2}-NiCr HVOF coating

Energy Technology Data Exchange (ETDEWEB)

Robertson, Andrew L., E-mail: Andrew.robertson99987@gmail.com; White, Ken W.

2017-03-14

Thermal spray coatings, often composed of heterogeneous, multiphase microstructures, may, consequently, exhibit complex fracture behavior. For such coating structures, conventional mechanical evaluation methods fail to isolate the contribution of microstructural features to the overall fracture behavior. For this reason, this study employed focused ion beam machined (FIB) microcantilever beams and FIB sectioning methods to study the fracture mechanisms important at the scale of the heterogeneous Cr{sub 3}C{sub 2}-NiCr thermal spray coating. We found three fracture modes, namely, intergranular matrix fracture, matrix/carbide interfacial fracture, and carbide cleavage. By comparison, microindentation-induced cracks, the frequency of crack deflection around carbides is significantly more prevalent at this much larger crack dimension. This mechanistic variation provides some insight into the specific role and limitations of the microcantilever beam technique for fracture characterization of composite microstructures.

[1,2,4]Triazolo[1,5-a]pyridine as Building Blocks for Universal Host Materials for High-Performance Red, Green, Blue and White Phosphorescent Organic Light-Emitting Devices.

Science.gov (United States)

Song, Wenxuan; Shi, Lijiang; Gao, Lei; Hu, Peijun; Mu, Haichuan; Xia, Zhenyuan; Huang, Jinhai; Su, Jianhua

2018-02-14

The electron-accepting [1,2,4]triazolo[1,5-a]pyridine (TP) moiety was introduced to build bipolar host materials for the first time, and two host materials based on this TP acceptor and carbazole donor, namely, 9,9'-(2-([1,2,4]triazolo[1,5-a]pyridin-2-yl)-1,3-phenylene)bis(9H-carbazole) (o-CzTP) and 9,9'-(5-([1,2,4]triazolo[1,5-a]pyridin-2-yl)-1,3-phenylene)bis(9H-carbazole) (m-CzTP), were designed and synthesized. These two TP-based host materials possess a high triplet energy (>2.9 eV) and appropriate highest occupied molecular orbital/lowest unoccupied molecular orbital levels as well as the bipolar transporting feature, which permits their applicability as universal host materials in multicolor phosphorescent organic light-emitting devices (PhOLEDs). Blue, green, and red PhOLEDs based on o-CzTP and m-CzTP with the same device configuration all show high efficiencies and low efficiency roll-off. The devices hosted by o-CzTP exhibit maximum external quantum efficiencies (η ext ) of 27.1, 25.0, and 15.8% for blue, green, and red light emitting, respectively, which are comparable with the best electroluminescene performance reported for FIrpic-based blue, Ir(ppy) 3 -based green, and Ir(pq) 2 (acac)-based red PhOLEDs equipped with a single-component host. The white PhOLEDs based on the o-CzTP host and three lumophors containing red, green, and blue emitting layers were fabricated with the same device structure, which exhibit a maximum current efficiency and η c of 40.4 cd/A and 17.8%, respectively, with the color rendering index value of 75.

Host-derived apolipoproteins play comparable roles with viral secretory proteins Erns and NS1 in the infectious particle formation of Flaviviridae.

Directory of Open Access Journals (Sweden)

Takasuke Fukuhara

2017-06-01

Full Text Available Amphipathic α-helices of exchangeable apolipoproteins have shown to play crucial roles in the formation of infectious hepatitis C virus (HCV particles through the interaction with viral particles. Among the Flaviviridae members, pestivirus and flavivirus possess a viral structural protein Erns or a non-structural protein 1 (NS1 as secretory glycoproteins, respectively, while Hepacivirus including HCV has no secretory glycoprotein. In case of pestivirus replication, the C-terminal long amphipathic α-helices of Erns are important for anchoring to viral membrane. Here we show that host-derived apolipoproteins play functional roles similar to those of virally encoded Erns and NS1 in the formation of infectious particles. We examined whether Erns and NS1 could compensate for the role of apolipoproteins in particle formation of HCV in apolipoprotein B (ApoB and ApoE double-knockout Huh7 (BE-KO, and non-hepatic 293T cells. We found that exogenous expression of either Erns or NS1 rescued infectious particle formation of HCV in the BE-KO and 293T cells. In addition, expression of apolipoproteins or NS1 partially rescued the production of infectious pestivirus particles in cells upon electroporation with an Erns-deleted non-infectious RNA. As with exchangeable apolipoproteins, the C-terminal amphipathic α-helices of Erns play the functional roles in the formation of infectious HCV or pestivirus particles. These results strongly suggest that the host- and virus-derived secretory glycoproteins have overlapping roles in the viral life cycle of Flaviviridae, especially in the maturation of infectious particles, while Erns and NS1 also participate in replication complex formation and viral entry, respectively. Considering the abundant hepatic expression and liver-specific propagation of these apolipoproteins, HCV might have evolved to utilize them in the formation of infectious particles through deletion of a secretory viral glycoprotein gene.

Host density and competency determine the effects of host diversity on trematode parasite infection.

Directory of Open Access Journals (Sweden)

Jeremy M Wojdak

Full Text Available Variation in host species composition can dramatically alter parasite transmission in natural communities. Whether diverse host communities dilute or amplify parasite transmission is thought to depend critically on species traits, particularly on how hosts affect each other's densities, and their relative competency as hosts. Here we studied a community of potential hosts and/or decoys (i.e. non-competent hosts for two trematode parasite species, Echinostoma trivolvis and Ribeiroia ondatrae, which commonly infect wildlife across North America. We manipulated the density of a focal host (green frog tadpoles, Rana clamitans, in concert with manipulating the diversity of alternative species, to simulate communities where alternative species either (1 replace the focal host species so that the total number of individuals remains constant (substitution or (2 add to total host density (addition. For E. trivolvis, we found that total parasite transmission remained roughly equal (or perhaps decreased slightly when alternative species replaced focal host individuals, but parasite transmission was higher when alternative species were added to a community without replacing focal host individuals. Given the alternative species were roughly equal in competency, these results are consistent with current theory. Remarkably, both total tadpole and per-capita tadpole infection intensity by E. trivolvis increased with increasing intraspecific host density. For R. ondatrae, alternative species did not function as effective decoys or hosts for parasite infective stages, and the diversity and density treatments did not produce clear changes in parasite transmission, although high tank to tank variation in R. ondatrae infection could have obscured patterns.

Host galaxies of type ia supernovae from the nearby supernova factory

Science.gov (United States)

Childress, Michael Joseph

Type Ia Supernovae (SNe Ia) are excellent distance indicators, yet the full details of the underlying physical mechanism giving rise to these dramatic stellar deaths remain unclear. As large samples of cosmological SNe Ia continue to be collected, the scatter in brightnesses of these events is equally affected by systematic errors as statistical. Thus we need to understand the physics of SNe Ia better, and in particular we must know more about the progenitors of these SNe so that we can derive better estimates for their true intrinsic brightnesses. The host galaxies of SNe Ia provide important indirect clues as to the nature of SN Ia progenitors. In this Thesis we utilize the host galaxies of SNe Ia discovered by the Nearby Supernova Factory (SNfactory) to pursue several key investigations into the nature of SN Ia progenitors and their effects on SN Ia brightnesses. We first examine the host galaxy of SN 2007if, an important member of the subclass of SNe Ia whose extreme brightnesses indicate a progenitor that exceeded the canonical Chandrasekhar-mass value presumed for normal SNe Ia, and show that the host galaxy of this SN is composed of very young stars and has extremely low metallicity, providing important constraints on progenitor scenarios for this SN. We then utilize the full sample of SNfactory host galaxy masses (measured from photometry) and metallicities (derived from optical spectroscopy) to examine several global properties of SN Ia progenitors: (i) we show that SN Ia hosts show tight agreement with the normal galaxy mass-metallicity relation; (ii) comparing the observed distribution of SN Ia host galaxy masses to a theoretical model that couples galaxy physics to the SN Ia delay time distribution (DTD), we show the power of the SN Ia host mass distribution in constraining the SN Ia DTD; and (iii) we show that the lack of ultra-low metallicities in the SNfactory SN Ia host sample gives provisional support for the theorized low-metallicity inhibition of

Anisometric C>60 Fullerene Colloids Assisted by Structure-Directing Agent

Energy Technology Data Exchange (ETDEWEB)

Penterman, S. [Cornell Univ., Ithaca, NY (United States); Liddell Watson, Chekesha M. [Cornell Univ., Ithaca, NY (United States); Escobedo, Fernando A. [Cornell Univ., Ithaca, NY (United States); Cohen, Itai [Cornell Univ., Ithaca, NY (United States)

2016-08-05

Colloidal synthesis and assembly provide low cost, large area routes to mesoscale structures. In particular, shape-anisotropic particles may form crystalline, plastic crystalline, complex liquid crystalline and glassy phases. Arrangements in each order class have been used to generate photonic materials. For example, large photonic band gaps have been found for photonic crystals, hyperuniform photonic glasses, and also for plastic crystals at sufficient refractive index contrast. The latter structures support highly isotropic bandgaps that are desirable for free-form waveguides and LED out-coupling. Photonic glasses with optical gain lead to self-tuned lasing by the superposition of multiply scattered light. Typically, extrinsic media such as organic dyes, rare earths, lanthanides and quantum dots are used to impart optical gain in photonic solids. The present work advances fullerene microcrystals as a new materials platform for ‘active’ light emitting in colloid-based photonic crystals. Fullerenes support singlet excited states that recombine to produce a characteristic red photoluminescence. C>60 also has a high refractive index (n ~ 2.2) and transparency (> 560 nm)⁹ so that inverse structures are not required.

Structural study of (N{sub 2}H{sub 5},H){sub 2.9}U{sub 1.1}Ce{sub 0.9}(C{sub 2}O{sub 4}){sub 5}·10H{sub 2}O from a conventional X-ray diffraction diagram obtained on a powder synthesized by a fast vortex process

Energy Technology Data Exchange (ETDEWEB)

Brackx, E., E-mail: Emmanuelle.brackx@cea.fr [CEA, DEN, DTEC, SGCS, LMAC, Marcoule, 30207 Bagnols sur Cèze (France); Laval, J.P. [Centre Européen de la Céramique, SPCTS, UMR-CNRS 7315, Université de Limoges, Faculté des Sciences, 12 rue Atlantis, 87068 Limoges (France); Dugne, O. [CEA, DEN, DTEC, SGCS, LMAC, Marcoule, 30207 Bagnols sur Cèze (France); Feraud, J.P. [CEA, DEN, DTEC, SGCS, LGCI, Marcoule, 30207 Bagnols sur Cèze (France); Arab-Chapelet, B. [CEA, DEN, DRCP, SCPS, LC2A, Marcoule, 30207 Bagnols sur Cèze (France)

2015-01-15

In the context of research on U/minor actinides for nuclear fuel reprocessing in the transmutation process, developments are first studied with surrogates containing uranium and lanthanides to facilitate testing. The tests consist of precipitating and calcining a hydrazinium uranium/cerium oxalate. The structure of this oxalate had not been previously determined, but was necessary to validate the physicochemical mechanisms involved. The present study, firstly demonstrates the structural similarity of the U/Ce oxalate phase (N{sub 2}H{sub 5},H){sub 2.9}U{sub 1.1}Ce{sub 0.9}(C{sub 2}O{sub 4}){sub 5}·10H{sub 2}O, synthesized using a vortex precipitator for continuous synthesis of actinide oxalates, with previously known oxalates, crystallizing in P6{sub 3}/mmc symmetry, obtained by more classical methods. This fast precipitation process induces massive nucleation of fine powders. Their structural and microstructural determination confirms that the raw and dried phases belong to the same structural family as (NH{sub 4}){sub 2}U{sub 2}(C{sub 2}O{sub 4}){sub 5}·0.7H{sub 2}O whose structure was described by Chapelet-Arab in P6{sub 3}/mmc symmetry, using single crystal data. However, they present an extended disorder inside the tunnels of the structure, even after drying at 100 °C, between water and hydrazinium ions. This disorder is directly related to the fast vortex method. This structure determination can be used as a basis for further semi-quantitative analysis on the U/minor actinides products formed under various experimental conditions. - Highlights: • Uranium cerium oxalate precipitate characterization by X-ray powder diffraction. • Morphology characterization by SEM analysis. • Structure determination by unit cell Rietveld refinement.

Ammonia-treated N-(1-naphthyl) ethylenediamine dihydrochloride as a novel matrix for rapid quantitative and qualitative determination of serum free fatty acids by matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yaping [Department of Biophysics and Structural Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dongdan San Tiao, Beijing 100005 (China); Wang, Yanmin [Department of Clinical Laboratory, Heze Municipal Hospital, Shandong (China); Guo, Shuai; Guo, Yumei; Liu, Hui [Department of Biophysics and Structural Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dongdan San Tiao, Beijing 100005 (China); Li, Zhili, E-mail: lizhili@ibms.pumc.edu.cn [Department of Biophysics and Structural Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dongdan San Tiao, Beijing 100005 (China)

2013-09-10

Graphical abstract: -- Highlights: •A novel MALDI matrix for the detection of serum free fatty acids is ammonia-treated N-(1-naphthyl) ethylenediamine dihydrochloride. •Multiple point internal standard calibration curves were constructed for nine FFAs, respectively, with excellent correlation coefficients between 0.991 and 0.999. •The MALDI-MS approach was used to rapidly differentiate the patients with and without hyperglycemia and healthy controls. -- Abstract: The blood free fatty acids (FFAs), which provide energy to the cell and act as substrates in the synthesis of fats, lipoproteins, liposaccharides, and eicosanoids, involve in a number of important physiological processes. In the present study, matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR MS) with ammonia-treated N-(1-naphthyl) ethylenediamine dihydrochloride (ATNEDC) as a novel MALDI matrix in a negative ion mode was employed to directly quantify serum FFAs. Multiple point internal standard calibration curves between the concentration ratios of individual fatty acids to internal standard (IS, C{sub 17:0}) versus their corresponding intensity ratios were constructed for C{sub 14:0}, C{sub 16:1}, C{sub 16:0}, C{sub 18:0}, C{sub 18:1}, C{sub 18:2}, C{sub 18:3}, C{sub 20:4}, and C{sub 22:6}, respectively, in their mixture, with correlation coefficients between 0.991 and 0.999 and limits of detection (LODs) between 0.2 and 5.4 μM, along with the linear dynamic range of more than two orders of magnitude. The results indicate that the multiple point internal standard calibration could reduce the impact of ion suppression and improve quantification accuracy in the MALDI mode. The quantitative results of nine FFAs from 339 serum samples, including 161 healthy controls, 118 patients with hyperglycemia and 60 patients without hyperglycemia show that FFAs levels in hyperglycemic patient sera are significantly higher than those in healthy

EPR of divalent manganese in non-Kramers hosts

Energy Technology Data Exchange (ETDEWEB)

Lech, J.; Slezak, A. [Institute of Physics, Technical University of Czestochowa, Czestochowa (Poland)

1997-12-31

Various interactions which lead to the observation of sharp EPR spectra of the high half-integer spin impurity Mn{sup 2+} (S=5/2) in paramagnetic hosts with integer spins S=1 and S=2 have been studied. Studies have been carried out on the basis of data extracted from experimental EPR spectra of Mn{sup 2+} in single crystal of divalent nickel Ni{sup 2+} (S=1) and Fe{sup 2+} (S=1) perchlorate hexahydrates. It has been shown that dipolar host-host and host-guest couplings broaden resonance lines of Mn{sup 2+}. Narrowing of the lines in the both crystals can be mainly attributed to the host-guest exchange interactions and quenching of the host spins. 19 refs, 3 figs, 1 tab.

Testing local host adaptation and phenotypic plasticity in a herbivore when alternative related host plants occur sympatrically.

Directory of Open Access Journals (Sweden)

Lorena Ruiz-Montoya

Full Text Available Host race formation in phytophagous insects can be an early stage of adaptive speciation. However, the evolution of phenotypic plasticity in host use is another possible outcome. Using a reciprocal transplant experiment we tested the hypothesis of local adaptation in the aphid Brevicoryne brassicae. Aphid genotypes derived from two sympatric host plants, Brassica oleracea and B. campestris, were assessed in order to measure the extent of phenotypic plasticity in morphological and life history traits in relation to the host plants. We obtained an index of phenotypic plasticity for each genotype. Morphological variation of aphids was summarized by principal components analysis. Significant effects of recipient host on morphological variation and life history traits (establishment, age at first reproduction, number of nymphs, and intrinsic growth rate were detected. We did not detected genotype × host plant interaction; in general the genotypes developed better on B. campestris, independent of the host plant species from which they were collected. Therefore, there was no evidence to suggest local adaptation. Regarding plasticity, significant differences among genotypes in the index of plasticity were detected. Furthermore, significant selection on PC1 (general aphid body size on B. campestris, and on PC1 and PC2 (body length relative to body size on B. oleracea was detected. The elevation of the reaction norm of PC1 and the slope of the reaction norm for PC2 (i.e., plasticity were under directional selection. Thus, host plant species constitute distinct selective environments for B. brassicae. Aphid genotypes expressed different phenotypes in response to the host plant with low or nil fitness costs. Phenotypic plasticity and gene flow limits natural selection for host specialization promoting the maintenance of genetic variation in host exploitation.

Pythium species from rice roots differ in virulence, host colonization and nutritional profile

OpenAIRE

Van Buyten, Evelien; Höfte, Monica

2013-01-01

Background: Progressive yield decline in Philippine aerobic rice fields has been recently associated with three closely related Pythium spp., P. arrhenomanes, P. graminicola and P. inflatum. To understand their differential virulence towards rice seedlings, we conducted a comparative survey in which three isolates each of P. arrhenomanes, P. graminicola and P. inflatum were selected to investigate host colonization, host responses and carbon utilization profiles using histopathological analys...

Entomopathogenic Fungi: New Insights into Host-Pathogen Interactions.

Science.gov (United States)

Butt, T M; Coates, C J; Dubovskiy, I M; Ratcliffe, N A

2016-01-01

Although many insects successfully live in dangerous environments exposed to diverse communities of microbes, they are often exploited and killed by specialist pathogens. Studies of host-pathogen interactions (HPI) provide valuable insights into the dynamics of the highly aggressive coevolutionary arms race between entomopathogenic fungi (EPF) and their arthropod hosts. The host defenses are designed to exclude the pathogen or mitigate the damage inflicted while the pathogen responds with immune evasion and utilization of host resources. EPF neutralize their immediate surroundings on the insect integument and benefit from the physiochemical properties of the cuticle and its compounds that exclude competing microbes. EPF also exhibit adaptations aimed at minimizing trauma that can be deleterious to both host and pathogen (eg, melanization of hemolymph), form narrow penetration pegs that alleviate host dehydration and produce blastospores that lack immunogenic sugars/enzymes but facilitate rapid assimilation of hemolymph nutrients. In response, insects deploy an extensive armory of hemocytes and macromolecules, such as lectins and phenoloxidase, that repel, immobilize, and kill EPF. New evidence suggests that immune bioactives work synergistically (eg, lysozyme with antimicrobial peptides) to combat infections. Some proteins, including transferrin and apolipophorin III, also demonstrate multifunctional properties, participating in metabolism, homeostasis, and pathogen recognition. This review discusses the molecular intricacies of these HPI, highlighting the interplay between immunity, stress management, and metabolism. Increased knowledge in this area could enhance the efficacy of EPF, ensuring their future in integrated pest management programs. Copyright © 2016 Elsevier Inc. All rights reserved.

EPA Region 1 - Map Layers for Valley ID Tool (Hosted Feature Service)

Science.gov (United States)

The Valley Service Feature Layer hosts spatial data for EPA Region 1's Valley Identification Tool. These layers contain attribute information added by EPA R1 GIS Center to help identify populated valleys:- Fac_2011NEI: Pollution sources selected from the National Emissions Inventory (EPA, 2011).- NE_Towns_PopValleys: New England Town polygons (courtesy USGS), with Population in Valleys and Population Density in Valleys calculated by EPA R1 GIS, from 2010 US Census blocks. - VT_E911: Vermont residences (courtesy VT Center for Geographic Information E-911).

Viral and Host Factors Required for Avian H5N1 Influenza A Virus Replication in Mammalian Cells

Directory of Open Access Journals (Sweden)

Hong Zhang

2013-06-01

Full Text Available Following the initial and sporadic emergence into humans of highly pathogenic avian H5N1 influenza A viruses in Hong Kong in 1997, we have come to realize the potential for avian influenza A viruses to be transmitted directly from birds to humans. Understanding the basic viral and cellular mechanisms that contribute to infection of mammalian species with avian influenza viruses is essential for developing prevention and control measures against possible future human pandemics. Multiple physical and functional cellular barriers can restrict influenza A virus infection in a new host species, including the cell membrane, the nuclear envelope, the nuclear environment, and innate antiviral responses. In this review, we summarize current knowledge on viral and host factors required for avian H5N1 influenza A viruses to successfully establish infections in mammalian cells. We focus on the molecular mechanisms underpinning mammalian host restrictions, as well as the adaptive mutations that are necessary for an avian influenza virus to overcome them. It is likely that many more viral and host determinants remain to be discovered, and future research in this area should provide novel and translational insights into the biology of influenza virus-host interactions.

The Genealogical Population Dynamics of HIV-1 in a Large Transmission Chain: Bridging within and among Host Evolutionary Rates

Science.gov (United States)

Vrancken, Bram; Rambaut, Andrew; Suchard, Marc A.; Drummond, Alexei; Baele, Guy; Derdelinckx, Inge; Van Wijngaerden, Eric; Vandamme, Anne-Mieke; Van Laethem, Kristel; Lemey, Philippe

2014-01-01

Transmission lies at the interface of human immunodeficiency virus type 1 (HIV-1) evolution within and among hosts and separates distinct selective pressures that impose differences in both the mode of diversification and the tempo of evolution. In the absence of comprehensive direct comparative analyses of the evolutionary processes at different biological scales, our understanding of how fast within-host HIV-1 evolutionary rates translate to lower rates at the between host level remains incomplete. Here, we address this by analyzing pol and env data from a large HIV-1 subtype C transmission chain for which both the timing and the direction is known for most transmission events. To this purpose, we develop a new transmission model in a Bayesian genealogical inference framework and demonstrate how to constrain the viral evolutionary history to be compatible with the transmission history while simultaneously inferring the within-host evolutionary and population dynamics. We show that accommodating a transmission bottleneck affords the best fit our data, but the sparse within-host HIV-1 sampling prevents accurate quantification of the concomitant loss in genetic diversity. We draw inference under the transmission model to estimate HIV-1 evolutionary rates among epidemiologically-related patients and demonstrate that they lie in between fast intra-host rates and lower rates among epidemiologically unrelated individuals infected with HIV subtype C. Using a new molecular clock approach, we quantify and find support for a lower evolutionary rate along branches that accommodate a transmission event or branches that represent the entire backbone of transmitted lineages in our transmission history. Finally, we recover the rate differences at the different biological scales for both synonymous and non-synonymous substitution rates, which is only compatible with the ‘store and retrieve’ hypothesis positing that viruses stored early in latently infected cells

Study of the double charge-changing collision cross-sections of H{sup +}, D{sup +}, Li{sup +} ions with organic molecules in the energy range 10-50 keV; Etude des sections efficaces de double echange de charges ({sigma}{sub 1-1}) d'ions H{sup +}, D{sup +}, Li{sup +} traversant differents gaz organiques dans une gamme d'energie comprise entre 10 et 50 keV

Energy Technology Data Exchange (ETDEWEB)

Farrokhi, S [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-07-01

The variation of the double charge-changing collision cross-sections of H{sup +}, D{sup +}, Li{sup +} ions with organic molecules (CH{sub 4}, C{sub 2}H{sub 6}, C{sub 3}H{sub 8}, C{sub 4}H{sub 10}) in the energy range 10-50 keV has been studied. Several maximums for {sigma}{sub 1-1} = f(E) have been shown. Their existence should be explained by the different possibilities of dissociating the target-molecules. The position of the maximums, for the H{sup +} {yields} H{sup -} and D{sup +} {yields} D{sup -} reactions is in good agreement with that defined by the Massey adiabatic relation. (author) [French] Nous avons etudie la variation de la section efficace de double echange de charges des ions H{sup +}, D{sup +}, Li{sup +} lors de la collision avec les molecules organiques de CH{sub 4}, C{sub 2}H{sub 6}, C{sub 3}H{sub 8}, C{sub 4}H{sub 10} dans la gamme d'energie comprise entre 10 et 50 keV. Les resultats obtenus ont montre plusieurs maximums de {sigma}{sub 1-1} f(E). L'existence de ces maximums pourrait etre expliquee par les differentes possibilites de dissociation des molecules cibles. La position des points maximaux concernant les reactions H{sup +} {yields} H{sup -} et D{sup +} {yields} D{sup -} est en bon accord avec celle definie par la relation adiabatique de MASSEY. (auteur)

Improved performances of red organic light-emitting devices by co-doping a rubrene derivative and DCJTB into tris-(8-hydroxyquinoline) aluminum host

Energy Technology Data Exchange (ETDEWEB)

Li Tianle [Physics Department, School of Science, Maoming University, Maoming 525000 (China); Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Li Wenlian, E-mail: wllioel@yahoo.com.c [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Li Xiao [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Chu Bei, E-mail: beichubox@hotmail.co [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Su Zisheng; Han Liangliang; Chen Yiren [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Hu Zhizhi; Zhang Zhiqiang [Optic Photo-Electronic Materials and Research Development Center, Liaoning University of Science and Technology, Anshan 114044 (China)

2010-10-15

Performances of red organic light-emitting device were improved by co-doping 2-formyl-5,6,11,12-tetraphenylnaphthacene (2FRb) and 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetra-methyljulolidyl-9-enyl) -4H-pyran (DCJTB) in tris-(8-hydroxyquinoline) aluminum (Alq{sub 3}) host as the emitting layer. The device with 1 wt% DCJTB and 2.4 w% 2FRb in Alq{sub 3} host gave a saturated red emission with CIE chromaticity coordinates of (0.65, 0.35) and a maximum current efficiency as high as 6.45 cd/A, which are 2 and 2.4 fold larger than that of the device with 1 wt% DCJTB (3.28 cd/A) in Alq{sub 3} host and the device with 2.4 wt% 2FRb (2.72 cd/A) in Alq{sub 3} host at the current density of 20 mA/cm{sup 2}, respectively. The improvement could be attributed to the effective utilization of host energy by both energy transfer and trapping in the electroluminescence process and the depression of concentration quenching between the dopants molecules.

Host factors that promote retrotransposon integration are similar in distantly related eukaryotes.

Directory of Open Access Journals (Sweden)

Sudhir Kumar Rai

2017-12-01

Full Text Available Retroviruses and Long Terminal Repeat (LTR-retrotransposons have distinct patterns of integration sites. The oncogenic potential of retrovirus-based vectors used in gene therapy is dependent on the selection of integration sites associated with promoters. The LTR-retrotransposon Tf1 of Schizosaccharomyces pombe is studied as a model for oncogenic retroviruses because it integrates into the promoters of stress response genes. Although integrases (INs encoded by retroviruses and LTR-retrotransposons are responsible for catalyzing the insertion of cDNA into the host genome, it is thought that distinct host factors are required for the efficiency and specificity of integration. We tested this hypothesis with a genome-wide screen of host factors that promote Tf1 integration. By combining an assay for transposition with a genetic assay that measures cDNA recombination we could identify factors that contribute differentially to integration. We utilized this assay to test a collection of 3,004 S. pombe strains with single gene deletions. Using these screens and immunoblot measures of Tf1 proteins, we identified a total of 61 genes that promote integration. The candidate integration factors participate in a range of processes including nuclear transport, transcription, mRNA processing, vesicle transport, chromatin structure and DNA repair. Two candidates, Rhp18 and the NineTeen complex were tested in two-hybrid assays and were found to interact with Tf1 IN. Surprisingly, a number of pathways we identified were found previously to promote integration of the LTR-retrotransposons Ty1 and Ty3 in Saccharomyces cerevisiae, indicating the contribution of host factors to integration are common in distantly related organisms. The DNA repair factors are of particular interest because they may identify the pathways that repair the single stranded gaps flanking the sites of strand transfer following integration of LTR retroelements.

Host factors that promote retrotransposon integration are similar in distantly related eukaryotes.

Science.gov (United States)

Rai, Sudhir Kumar; Sangesland, Maya; Lee, Michael; Esnault, Caroline; Cui, Yujin; Chatterjee, Atreyi Ghatak; Levin, Henry L

2017-12-01

Retroviruses and Long Terminal Repeat (LTR)-retrotransposons have distinct patterns of integration sites. The oncogenic potential of retrovirus-based vectors used in gene therapy is dependent on the selection of integration sites associated with promoters. The LTR-retrotransposon Tf1 of Schizosaccharomyces pombe is studied as a model for oncogenic retroviruses because it integrates into the promoters of stress response genes. Although integrases (INs) encoded by retroviruses and LTR-retrotransposons are responsible for catalyzing the insertion of cDNA into the host genome, it is thought that distinct host factors are required for the efficiency and specificity of integration. We tested this hypothesis with a genome-wide screen of host factors that promote Tf1 integration. By combining an assay for transposition with a genetic assay that measures cDNA recombination we could identify factors that contribute differentially to integration. We utilized this assay to test a collection of 3,004 S. pombe strains with single gene deletions. Using these screens and immunoblot measures of Tf1 proteins, we identified a total of 61 genes that promote integration. The candidate integration factors participate in a range of processes including nuclear transport, transcription, mRNA processing, vesicle transport, chromatin structure and DNA repair. Two candidates, Rhp18 and the NineTeen complex were tested in two-hybrid assays and were found to interact with Tf1 IN. Surprisingly, a number of pathways we identified were found previously to promote integration of the LTR-retrotransposons Ty1 and Ty3 in Saccharomyces cerevisiae, indicating the contribution of host factors to integration are common in distantly related organisms. The DNA repair factors are of particular interest because they may identify the pathways that repair the single stranded gaps flanking the sites of strand transfer following integration of LTR retroelements.

Differential recognition and hydrolysis of host carbohydrate antigens by Streptococcus pneumoniae family 98 glycoside hydrolases.

Science.gov (United States)

Higgins, Melanie A; Whitworth, Garrett E; El Warry, Nahida; Randriantsoa, Mialy; Samain, Eric; Burke, Robert D; Vocadlo, David J; Boraston, Alisdair B

2009-09-18

The presence of a fucose utilization operon in the Streptococcus pneumoniae genome and its established importance in virulence indicates a reliance of this bacterium on the harvesting of host fucose-containing glycans. The identities of these glycans, however, and how they are harvested is presently unknown. The biochemical and high resolution x-ray crystallographic analysis of two family 98 glycoside hydrolases (GH98s) from distinctive forms of the fucose utilization operon that originate from different S. pneumoniae strains reveal that one enzyme, the predominant type among pneumococcal isolates, has a unique endo-beta-galactosidase activity on the LewisY antigen. Altered active site topography in the other species of GH98 enzyme tune its endo-beta-galactosidase activity to the blood group A and B antigens. Despite their different specificities, these enzymes, and by extension all family 98 glycoside hydrolases, use an inverting catalytic mechanism. Many bacterial and viral pathogens exploit host carbohydrate antigens for adherence as a precursor to colonization or infection. However, this is the first evidence of bacterial endoglycosidase enzymes that are known to play a role in virulence and are specific for distinct host carbohydrate antigens. The strain-specific distribution of two distinct types of GH98 enzymes further suggests that S. pneumoniae strains may specialize to exploit host-specific antigens that vary from host to host, a factor that may feature in whether a strain is capable of colonizing a host or establishing an invasive infection.

Myelopotentiating effect of curcumin in tumor-bearing host: Role of bone marrow resident macrophages

Energy Technology Data Exchange (ETDEWEB)

Vishvakarma, Naveen Kumar; Kumar, Anjani; Kumar, Ajay; Kant, Shiva [School of Biotechnology, Banaras Hindu University, Varanasi-221 005, U.P. (India); Bharti, Alok Chandra [Division of Molecular Oncology, Institute of Cytology and Preventive Oncology, Noida, UP (India); Singh, Sukh Mahendra, E-mail: sukhmahendrasingh@yahoo.com [School of Biotechnology, Banaras Hindu University, Varanasi-221 005, U.P. (India)

2012-08-15

The present investigation was undertaken to study if curcumin, which is recognized for its potential as an antineoplastic and immunopotentiating agent, can also influence the process of myelopoiesis in a tumor-bearing host. Administration of curcumin to tumor-bearing host augmented count of bone marrow cell (BMC) accompanied by an up-regulated BMC survival and a declined induction of apoptosis. Curcumin administration modulated expression of cell survival regulatory molecules: Bcl2, p53, caspase-activated DNase (CAD) and p53-upregulated modulator of apoptosis (PUMA) along with enhanced expression of genes of receptors for M-CSF and GM-CSF in BMC. The BMC harvested from curcumin-administered hosts showed an up-regulated colony forming ability with predominant differentiation into bone marrow-derived macrophages (BMDM), responsive for activation to tumoricidal state. The number of F4/80 positive bone marrow resident macrophages (BMM), showing an augmented expression of M-CSF, was also augmented in the bone marrow of curcumin-administered host. In vitro reconstitution experiments indicated that only BMM of curcumin-administered hosts, but not in vitro curcumin-exposed BMM, augmented BMC survival. It suggests that curcumin-dependent modulation of BMM is of indirect nature. Such prosurvival action of curcumin is associated with altered T{sub H1}/T{sub H2} cytokine balance in serum. Augmented level of serum-borne IFN-γ was found to mediate modulation of BMM to produce enhanced amount of monokines (IL-1, IL-6, TNF-α), which are suggested to augment the BMC survival. Taken together the present investigation indicates that curcumin can potentiate myelopoiesis in a tumor-bearing host, which may have implications in its therapeutic utility. Highlights: ► Curcumin augments myelopoiesis in tumor-bearing host. ► Bone marrow resident macrophages mediate curcumin-dependent augmented myelopoiesis. ► Serum borne cytokine are implicated in modulation of bone marrow resident

Myelopotentiating effect of curcumin in tumor-bearing host: Role of bone marrow resident macrophages

International Nuclear Information System (INIS)

Vishvakarma, Naveen Kumar; Kumar, Anjani; Kumar, Ajay; Kant, Shiva; Bharti, Alok Chandra; Singh, Sukh Mahendra

2012-01-01

The present investigation was undertaken to study if curcumin, which is recognized for its potential as an antineoplastic and immunopotentiating agent, can also influence the process of myelopoiesis in a tumor-bearing host. Administration of curcumin to tumor-bearing host augmented count of bone marrow cell (BMC) accompanied by an up-regulated BMC survival and a declined induction of apoptosis. Curcumin administration modulated expression of cell survival regulatory molecules: Bcl2, p53, caspase-activated DNase (CAD) and p53-upregulated modulator of apoptosis (PUMA) along with enhanced expression of genes of receptors for M-CSF and GM-CSF in BMC. The BMC harvested from curcumin-administered hosts showed an up-regulated colony forming ability with predominant differentiation into bone marrow-derived macrophages (BMDM), responsive for activation to tumoricidal state. The number of F4/80 positive bone marrow resident macrophages (BMM), showing an augmented expression of M-CSF, was also augmented in the bone marrow of curcumin-administered host. In vitro reconstitution experiments indicated that only BMM of curcumin-administered hosts, but not in vitro curcumin-exposed BMM, augmented BMC survival. It suggests that curcumin-dependent modulation of BMM is of indirect nature. Such prosurvival action of curcumin is associated with altered T H1 /T H2 cytokine balance in serum. Augmented level of serum-borne IFN-γ was found to mediate modulation of BMM to produce enhanced amount of monokines (IL-1, IL-6, TNF-α), which are suggested to augment the BMC survival. Taken together the present investigation indicates that curcumin can potentiate myelopoiesis in a tumor-bearing host, which may have implications in its therapeutic utility. Highlights: ► Curcumin augments myelopoiesis in tumor-bearing host. ► Bone marrow resident macrophages mediate curcumin-dependent augmented myelopoiesis. ► Serum borne cytokine are implicated in modulation of bone marrow resident

Energetics and chemical bonding of the 1,3,5-tridehydrobenzene triradical and its protonated form

Energy Technology Data Exchange (ETDEWEB)

Hue Minh Thi Nguyen [Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Leuven (Belgium); Faculty of Chemistry, University of Education, Hanoi (Viet Nam); Hoeltzl, Tibor [Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Leuven (Belgium); Department of Inorganic Chemistry, University of Technology and Economics Gellert ter 4, H-1521-Budapest (Hungary); Gopakumar, G. [Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Leuven (Belgium); Veszpremi, Tamas [Department of Inorganic Chemistry, University of Technology and Economics Gellert ter 4, H-1521-Budapest (Hungary); Peeters, Jozef [Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Leuven (Belgium); Minh Tho Nguyen [Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Leuven (Belgium)], E-mail: minh.nguyen@chem.kuleuven.be

2005-09-19

Quantum chemical calculations were applied to investigate the electronic structure of the parent 1,3,5-tridehydrobenzene triradical (C{sub 6}H{sub 3}, TDB) and its anion (C{sub 6}H{sub 3}{sup -}), cation (C{sub 6}H{sub 3}{sup +}) and protonated form (C{sub 6}H{sub 4}{sup +}). Our results obtained using the state-averaged complete active space self-consistent-field (CASSCF) followed by second-order multi-state multi-configuration perturbation theory, MS-CASPT2, and MRMP2 in conjunction with the large ANO-L and 6-311++G(3df,2p) basis set, confirm and reveal the followings: (i) TDB has a doublet {sup 2}A{sub 1} ground state with a {sup 4}B{sub 2}-{sup 2}A{sub 1} energy gap of 29kcal/mol, (ii) the ground state of the C{sub 6}H{sub 3}{sup -} anion in the triplet {sup 3}B{sub 2} being 4kcal/mol below the {sup 1}A{sub 1} state. (iii) the electron affinity (EA), ionization energy (IE) and proton affinity (PA) are computed to be: EA=1.6eV, IE=7.2eV, PA=227kcal/mol using UB3LYP/6-311++G(3df,2p)+ZPE; standard heat of formation {delta}H{sub f(298K,1atm)}(TDB)=179+/-2kcal/mol was calculated with CBS-QB3 method. An atoms-in-molecules (AIM) analysis of the structure reveals that the topology of the electron density is similar in all compounds: hydrogens connect to a six-membered ring, except for the case of the {sup 2}A{sub 2} state of C{sub 6}H{sub 4}{sup +} (MBZ{sup +}) which is bicyclic with fused five- and three-membered rings. Properties of the chemical bonds were characterized with Electron Localization Function (ELF) analysis, as well as Wiberg indices, Laplacian and spin density maps. We found that the radicals form separate monosynaptic basins on the ELF space, however its pair character remains high. In the {sup 2}A{sub 1} state of TDB, the radical center is mainly localized on the C1 atom, while in the {sup 2}B{sub 2} state it is equally distributed between the C3 and C5 atoms and, due to the symmetry, in the {sup 4}B{sub 2} state the C1, C2 and C3 atoms have the same

Intrinsic decoherence theory applied to single C{sub 60} solid state transistors: Robustness in the transmission regimen

Energy Technology Data Exchange (ETDEWEB)

Flores, J.C., E-mail: cflores@uta.cl

2016-03-06

In relation to a given Hamiltonian and intrinsic decoherence, there are subspaces for which coherence remains robust. Robustness can be classified by the parameter ratios (integer, rational or irrational numbers) defining each subspace. Of particular novelty in this work is application to the single-C{sub 60} transistor where coherence becomes robust in the tunnel transmission regime. In this case, the intrinsic-decoherence parameter defining the theory is explicitly evaluated in good agreement with experimental data. Many of these results are expected to hold for standard quantum dots and mesoscopic devices. - Highlights: • Intrinsic decoherence and transport (mesoscopic). • Robustness condition face to decoherence. • Application to the single C{sub 60} solid state transistor. • Parameter determination based on experiments. • Other cases of robustness.

Viral Mimicry to Usurp Ubiquitin and SUMO Host Pathways

Directory of Open Access Journals (Sweden)

Peter Wimmer

2015-08-01

Full Text Available Posttranslational modifications (PTMs of proteins include enzymatic changes by covalent addition of cellular regulatory determinants such as ubiquitin (Ub and small ubiquitin-like modifier (SUMO moieties. These modifications are widely used by eukaryotic cells to control the functional repertoire of proteins. Over the last decade, it became apparent that the repertoire of ubiquitiylation and SUMOylation regulating various biological functions is not restricted to eukaryotic cells, but is also a feature of human virus families, used to extensively exploit complex host-cell networks and homeostasis. Intriguingly, besides binding to host SUMO/Ub control proteins and interfering with the respective enzymatic cascade, many viral proteins mimic key regulatory factors to usurp this host machinery and promote efficient viral outcomes. Advanced detection methods and functional studies of ubiquitiylation and SUMOylation during virus-host interplay have revealed that human viruses have evolved a large arsenal of strategies to exploit these specific PTM processes. In this review, we highlight the known viral analogs orchestrating ubiquitin and SUMO conjugation events to subvert and utilize basic enzymatic pathways.

Synthesis, structure and electronic configuration of [Rh{sub 6}Te{sub 8}(PPh{sub 3}){sub 6}].4C{sub 6}H{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Thiele, Guenther; Balmer, Markus [Marburg Univ. (Germany). Fachbereich Chemie; Dehnen, Stefanie [Marburg Univ. (Germany). Fachbereich Chemie and Wissenschaftliches Zentrum fuer Materialwissenschaften

2016-08-01

[Rh{sub 6}Te{sub 8}(PPh{sub 3}){sub 6}].4C{sub 6}H{sub 6}, the first compound with a molecular Chevrel-type [Rh{sub 6}Te{sub 8}] cluster core has been synthesized and structurally characterized. By means of quantum chemical calculation, the close relationship of its electronic configuration to that of the lighter homologue has been demonstrated. The different crystal solvent content prevents an isostructural crystallization.

The interactomes of influenza virus NS1 and NS2 proteins identify new host factors and provide insights for ADAR1 playing a supportive role in virus replication.

Science.gov (United States)

de Chassey, Benoît; Aublin-Gex, Anne; Ruggieri, Alessia; Meyniel-Schicklin, Laurène; Pradezynski, Fabrine; Davoust, Nathalie; Chantier, Thibault; Tafforeau, Lionel; Mangeot, Philippe-Emmanuel; Ciancia, Claire; Perrin-Cocon, Laure; Bartenschlager, Ralf; André, Patrice; Lotteau, Vincent

2013-01-01

Influenza A NS1 and NS2 proteins are encoded by the RNA segment 8 of the viral genome. NS1 is a multifunctional protein and a virulence factor while NS2 is involved in nuclear export of viral ribonucleoprotein complexes. A yeast two-hybrid screening strategy was used to identify host factors supporting NS1 and NS2 functions. More than 560 interactions between 79 cellular proteins and NS1 and NS2 proteins from 9 different influenza virus strains have been identified. These interacting proteins are potentially involved in each step of the infectious process and their contribution to viral replication was tested by RNA interference. Validation of the relevance of these host cell proteins for the viral replication cycle revealed that 7 of the 79 NS1 and/or NS2-interacting proteins positively or negatively controlled virus replication. One of the main factors targeted by NS1 of all virus strains was double-stranded RNA binding domain protein family. In particular, adenosine deaminase acting on RNA 1 (ADAR1) appeared as a pro-viral host factor whose expression is necessary for optimal viral protein synthesis and replication. Surprisingly, ADAR1 also appeared as a pro-viral host factor for dengue virus replication and directly interacted with the viral NS3 protein. ADAR1 editing activity was enhanced by both viruses through dengue virus NS3 and influenza virus NS1 proteins, suggesting a similar virus-host co-evolution.

The interactomes of influenza virus NS1 and NS2 proteins identify new host factors and provide insights for ADAR1 playing a supportive role in virus replication.

Directory of Open Access Journals (Sweden)

Benoît de Chassey

Full Text Available Influenza A NS1 and NS2 proteins are encoded by the RNA segment 8 of the viral genome. NS1 is a multifunctional protein and a virulence factor while NS2 is involved in nuclear export of viral ribonucleoprotein complexes. A yeast two-hybrid screening strategy was used to identify host factors supporting NS1 and NS2 functions. More than 560 interactions between 79 cellular proteins and NS1 and NS2 proteins from 9 different influenza virus strains have been identified. These interacting proteins are potentially involved in each step of the infectious process and their contribution to viral replication was tested by RNA interference. Validation of the relevance of these host cell proteins for the viral replication cycle revealed that 7 of the 79 NS1 and/or NS2-interacting proteins positively or negatively controlled virus replication. One of the main factors targeted by NS1 of all virus strains was double-stranded RNA binding domain protein family. In particular, adenosine deaminase acting on RNA 1 (ADAR1 appeared as a pro-viral host factor whose expression is necessary for optimal viral protein synthesis and replication. Surprisingly, ADAR1 also appeared as a pro-viral host factor for dengue virus replication and directly interacted with the viral NS3 protein. ADAR1 editing activity was enhanced by both viruses through dengue virus NS3 and influenza virus NS1 proteins, suggesting a similar virus-host co-evolution.

48 CFR 1845.7210-1 - Utilization surveys.

Science.gov (United States)

2010-10-01

... report Government-owned plant equipment in accordance with FAR 45.502(g) and 45.509-2(b)(4). Items that... ADMINISTRATION CONTRACT MANAGEMENT GOVERNMENT PROPERTY Contract Property Management 1845.7210-1 Utilization surveys. (a) The property administrator is responsible for ensuring that the contractor has effective...

Theoretical studies of the local structure and electron paramagnetic resonance parameters for tetragonal VO{sup 2+} in C{sub 6}H{sub 7}KO{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Zhou, Ping [Chongqing Jiaotong Univ. (China). School of Science; Li, Ling [Sichuan University of Arts and Science, Dazhou (China). Dept. of Maths and Finance-Economics

2015-07-01

The optical spectra, electron paramagnetic resonance parameters (i.e., the spin Hamiltonian parameters, including paramagnetic g factors and the hyperfine structure constants A{sub i}) and the local distortion structure for the tetragonal VO{sup 2+} in C{sub 6}H{sub 7}KO{sub 7} are theoretically studied based on the crystal-field theory and three-order perturbation formulas of a 3d{sup 1} centre in tetragonal site. The magnitude of orbital reduction factor, core polarisation constant κ, and local structure parameters are obtained by fitting the calculated optical spectra and electron paramagnetic resonance parameters to the experimental values. The theoretical results are in reasonable agreement with the experimental values.

Comparison of dosimetric protocols to beamy of photons and electrons

Energy Technology Data Exchange (ETDEWEB)

Anglesio, S; Ragona, R; Cesana, P; Spandonari, T

1986-01-01

I+n this work different methods for the calculus of the absorbed dose at different photon and electron energies are utilized and the differences between their yields are evaluated. One of these methods is based on the consideration of the factors Csub(lambda) and Csub(E) (ICRU, HPA, AAPM protocols before 1980); by means of the others (AAPM-Task Group 21, NACP) we seek to obtain a better accuracy introducing new conversion factors. Our measurements were performed using cylindrical and flat ionisation chambers. In the considered energy range we obtained the following results: the new conversion factors have a higher avalue than Csub(lambda) and always smaller than Csub(E).

Host Phylogeny Determines Viral Persistence and Replication in Novel Hosts

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Longdon, Ben; Hadfield, Jarrod D.; Webster, Claire L.

2011-01-01

Pathogens switching to new hosts can result in the emergence of new infectious diseases, and determining which species are likely to be sources of such host shifts is essential to understanding disease threats to both humans and wildlife. However, the factors that determine whether a pathogen can infect a novel host are poorly understood. We have examined the ability of three host-specific RNA-viruses (Drosophila sigma viruses from the family Rhabdoviridae) to persist and replicate in 51 different species of Drosophilidae. Using a novel analytical approach we found that the host phylogeny could explain most of the variation in viral replication and persistence between different host species. This effect is partly driven by viruses reaching a higher titre in those novel hosts most closely related to the original host. However, there is also a strong effect of host phylogeny that is independent of the distance from the original host, with viral titres being similar in groups of related hosts. Most of this effect could be explained by variation in general susceptibility to all three sigma viruses, as there is a strong phylogenetic correlation in the titres of the three viruses. These results suggest that the source of new emerging diseases may often be predictable from the host phylogeny, but that the effect may be more complex than simply causing most host shifts to occur between closely related hosts. PMID:21966271

Chlamydia trachomatis co-opts GBF1 and CERT to acquire host sphingomyelin for distinct roles during intracellular development.

Directory of Open Access Journals (Sweden)

Cherilyn A Elwell

2011-09-01

Full Text Available The strain designated Chlamydia trachomatis serovar that was used for experiments in this paper is Chlamydia muridarum, a species closely related to C. trachomatis (and formerly termed the Mouse Pneumonitis strain of C. trachomatis. [corrected]. The obligate intracellular pathogen Chlamydia trachomatis replicates within a membrane-bound inclusion that acquires host sphingomyelin (SM, a process that is essential for replication as well as inclusion biogenesis. Previous studies demonstrate that SM is acquired by a Brefeldin A (BFA-sensitive vesicular trafficking pathway, although paradoxically, this pathway is dispensable for bacterial replication. This finding suggests that other lipid transport mechanisms are involved in the acquisition of host SM. In this work, we interrogated the role of specific components of BFA-sensitive and BFA-insensitive lipid trafficking pathways to define their contribution in SM acquisition during infection. We found that C. trachomatis hijacks components of both vesicular and non-vesicular lipid trafficking pathways for SM acquisition but that the SM obtained from these separate pathways is being utilized by the pathogen in different ways. We show that C. trachomatis selectively co-opts only one of the three known BFA targets, GBF1, a regulator of Arf1-dependent vesicular trafficking within the early secretory pathway for vesicle-mediated SM acquisition. The Arf1/GBF1-dependent pathway of SM acquisition is essential for inclusion membrane growth and stability but is not required for bacterial replication. In contrast, we show that C. trachomatis co-opts CERT, a lipid transfer protein that is a key component in non-vesicular ER to trans-Golgi trafficking of ceramide (the precursor for SM, for C. trachomatis replication. We demonstrate that C. trachomatis recruits CERT, its ER binding partner, VAP-A, and SM synthases, SMS1 and SMS2, to the inclusion and propose that these proteins establish an on-site SM biosynthetic

Dual transcriptomics of virus-host interactions: comparing two Pacific oyster families presenting contrasted susceptibility to ostreid herpesvirus 1.

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Segarra, Amélie; Mauduit, Florian; Faury, Nicole; Trancart, Suzanne; Dégremont, Lionel; Tourbiez, Delphine; Haffner, Philippe; Barbosa-Solomieu, Valérie; Pépin, Jean-François; Travers, Marie-Agnès; Renault, Tristan

2014-07-09

Massive mortality outbreaks affecting Pacific oyster (Crassostrea gigas) spat in various countries have been associated with the detection of a herpesvirus called ostreid herpesvirus type 1 (OsHV-1). However, few studies have been performed to understand and follow viral gene expression, as it has been done in vertebrate herpesviruses. In this work, experimental infection trials of C. gigas spat with OsHV-1 were conducted in order to test the susceptibility of several bi-parental oyster families to this virus and to analyze host-pathogen interactions using in vivo transcriptomic approaches. The divergent response of these oyster families in terms of mortality confirmed that susceptibility to OsHV-1 infection has a significant genetic component. Two families with contrasted survival rates were selected. A total of 39 viral genes and five host genes were monitored by real-time PCR. Initial results provided information on (i) the virus cycle of OsHV-1 based on the kinetics of viral DNA replication and transcription and (ii) host defense mechanisms against the virus. In the two selected families, the detected amounts of viral DNA and RNA were significantly different. This result suggests that Pacific oysters are genetically diverse in terms of their susceptibility to OsHV-1 infection. This contrasted susceptibility was associated with dissimilar host gene expression profiles. Moreover, the present study showed a positive correlation between viral DNA amounts and the level of expression of selected oyster genes.

Echinococcus-Host Interactions at Cellular and Molecular Levels.

Science.gov (United States)

Brehm, K; Koziol, U

2017-01-01

The potentially lethal zoonotic diseases alveolar and cystic echinococcosis are caused by the metacestode larval stages of the tapeworms Echinococcus multilocularis and Echinococcus granulosus, respectively. In both cases, metacestode growth and proliferation occurs within the inner organs of mammalian hosts, which is associated with complex molecular host-parasite interactions that regulate nutrient uptake by the parasite as well as metacestode persistence and development. Using in vitro cultivation systems for parasite larvae, and informed by recently released, comprehensive genome and transcriptome data for both parasites, these molecular host-parasite interactions have been subject to significant research during recent years. In this review, we discuss progress in this field, with emphasis on parasite development and proliferation. We review host-parasite interaction mechanisms that occur early during an infection, when the invading oncosphere stage undergoes a metamorphosis towards the metacestode, and outline the decisive role of parasite stem cells during this process. We also discuss special features of metacestode morphology, and how this parasite stage takes up nutrients from the host, utilizing newly evolved or expanded gene families. We comprehensively review mechanisms of host-parasite cross-communication via evolutionarily conserved signalling systems and how the parasite signalling systems might be exploited for the development of novel chemotherapeutics. Finally, we point to an urgent need for the development of functional genomic techniques in this parasite, which will be imperative for hypothesis-driven analyses into Echinococcus stem cell biology, developmental mechanisms and immunomodulatory activities, which are all highly relevant for the development of anti-infective measures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nanomechanical properties of SiC films grown from C{sub 60} precursors using atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Morse, K. [Colorado School of Mines, Golden, CO (United States); Balooch, M.; Hamza, A.V.; Belak, J. [Lawrence Livermore National Lab., CA (United States)

1994-12-01

The mechanical properties of SiC films grown via C{sub 60} precursors were determined using atomic force microscopy (AFM). Conventional silicon nitride and modified diamond cantilever AFM tips were employed to determine the film hardness, friction coefficient, and elastic modulus. The hardness is found to be between 26 and 40 GPa by nanoindentation of the film with the diamond tip. The friction coefficient for the silicon nitride tip on the SiC film is about one third that for silicon nitride sliding on a silicon substrate. By combining nanoindentation and AFM measurements an elastic modulus of {approximately}300 GPa is estimated for these SiC films. In order to better understand the atomic scale mechanisms that determine the hardness and friction of SiC, we simulated the molecular dynamics of a diamond indenting a crystalline SiC substrate.

Comparative genomics of Lactobacillus salivarius strains focusing on their host adaptation.

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Lee, Jun-Yeong; Han, Geon Goo; Kim, Eun Bae; Choi, Yun-Jaie

2017-12-01

Lactobacillus salivarius is an important member of the animal gut microflora and is a promising probiotic bacterium. However, there is a lack of research on the genomic diversity of L. salivarius species. In this study, we generated 21 L. salivarius draft genomes, and investigated the pan-genome of L. salivarius strains isolated from humans, pigs and chickens using all available genomes, focusing on host adaptation. Phylogenetic clustering showed a distinct categorization of L. salivarius strains depending on their hosts. In the pan-genome, 15 host-specific genes and 16 dual-host-shared genes that only one host isolate did not possess were identified. Comparison of 56 extracellular protein encoding genes and 124 orthologs related to exopolysaccharide production in the pan-genome revealed that extracellular components of the assayed bacteria have been globally acquired and mutated under the selection pressure for host adaptation. We also found the three host-specific genes that are responsible for energy production in L. salivarius. These results showed that L. salivarius has evolved to adapt to host habitats in two ways, by gaining the abilities for niche adhesion and efficient utilization of nutrients. Our study offers a deeper understanding of the probiotic species L. salivarius, and provides a basis for future studies on L. salivarius and other mutualistic bacteria. Copyright © 2017 Elsevier GmbH. All rights reserved.

Microsporidia infection impacts the host cell's cycle and reduces host cell apoptosis

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Higes, Mariano; Sagastume, Soledad; Juarranz, Ángeles; Dias-Almeida, Joyce; Budge, Giles E.; Meana, Aránzazu; Boonham, Neil

2017-01-01

Intracellular parasites can alter the cellular machinery of host cells to create a safe haven for their survival. In this regard, microsporidia are obligate intracellular fungal parasites with extremely reduced genomes and hence, they are strongly dependent on their host for energy and resources. To date, there are few studies into host cell manipulation by microsporidia, most of which have focused on morphological aspects. The microsporidia Nosema apis and Nosema ceranae are worldwide parasites of honey bees, infecting their ventricular epithelial cells. In this work, quantitative gene expression and histology were studied to investigate how these two parasites manipulate their host’s cells at the molecular level. Both these microsporidia provoke infection-induced regulation of genes involved in apoptosis and the cell cycle. The up-regulation of buffy (which encodes a pro-survival protein) and BIRC5 (belonging to the Inhibitor Apoptosis protein family) was observed after infection, shedding light on the pathways that these pathogens use to inhibit host cell apoptosis. Curiously, different routes related to cell cycle were modified after infection by each microsporidia. In the case of N. apis, cyclin B1, dacapo and E2F2 were up-regulated, whereas only cyclin E was up-regulated by N. ceranae, in both cases promoting the G1/S phase transition. This is the first report describing molecular pathways related to parasite-host interactions that are probably intended to ensure the parasite’s survival within the cell. PMID:28152065