WorldWideScience

Sample records for points polypeptides h2

  1. H2O frost point detection on Mars

    Science.gov (United States)

    Ryan, J. A.; Sharman, R. D.

    1981-01-01

    The Viking Mars landers contain meteorological instrumentation to measure wind, temperature, and pressure but not atmospheric water content. The landings occurred during local summer, and it was observed that the nocturnal temperature decrease at sensor height (1.6 m) did not exhibit a uniform behavior at either site. It was expected that the rate of decrease would gradually slow, leveling off near sunrise. Instead, a leveling occurred several hours earlier. Temperature subsequently began a more rapid decrease which slowed by sunrise. This suggested that the temperature sensors may be detecting the frost point of water vapor. Analysis of alternative hypotheses demonstrates that none of these are viable candidates. The frost point interpretation is consistent with other lander and orbiter observations, with terrestrial experience, and with modeling of Mars' atmospheric behavior. It thus appears that the meteorology experiment can help provide a basis toward understanding the distribution and dynamics of Martian water vapor.

  2. Zero-point energy, tunnelling, and vibrational adiabaticity in the Mu + H2 reaction

    Science.gov (United States)

    Mielke, Steven L.; Garrett, Bruce C.; Fleming, Donald G.; Truhlar, Donald G.

    2015-01-01

    Isotopic substitution of muonium for hydrogen provides an unparalleled opportunity to deepen our understanding of quantum mass effects on chemical reactions. A recent topical review in this journal of the thermal and vibrationally state-selected reaction of Mu with H2 raises a number of issues that are addressed here. We show that some earlier quantum mechanical calculations of the Mu + H2 reaction, which are highlighted in this review, and which have been used to benchmark approximate methods, are in error by as much as 19% in the low-temperature limit. We demonstrate that an approximate treatment of the Born-Oppenheimer diagonal correction that was used in some recent studies is not valid for treating the vibrationally state-selected reaction. We also discuss why vibrationally adiabatic potentials that neglect bend zero-point energy are not a useful analytical tool for understanding reaction rates, and why vibrationally non-adiabatic transitions cannot be understood by considering tunnelling through vibrationally adiabatic potentials. Finally, we present calculations on a hierarchical family of potential energy surfaces to assess the sensitivity of rate constants to the quality of the potential surface.

  3. Critical points of the conformational potential energy surface of carbonic acid: H 2CO 3

    Science.gov (United States)

    Janoschek, Rudolf; Csizmadia, Imre G.

    1993-12-01

    The conformational potential energy surface E  E( T1, T2) of H 2CO 3, where T1 is the torsional angle for HO 1CO 2 and T2 is the torsional angle for O 1CO 2H, revealed that the anti—anti conformation is the global minimum. Additional local minima were also found. The next higher energy conformation was the syn—anti conformation, and a degenerate pair of right handed and left handed helical conformations were the highest on the energy scale. The syn—syn conformation turned out to be a transition structure sandwiched between the two helical conformation.

  4. Primary structure of a constituent polypeptide chain (AIII) of the giant haemoglobin from the deep-sea tube worm Lamellibrachia. A possible H2S-binding site.

    Science.gov (United States)

    Suzuki, T; Takagi, T; Ohta, S

    1990-02-15

    The deep-sea tube worm Lamellibrachia, belonging to the Phylum Vestimentifera, contains two giant extracellular haemoglobins, a 3000 kDa haemoglobin and a 440 kDa haemoglobin. The former consists of four haem-containing chains (AI-AIV) and two linker chains (AV and AVI) for the assembly of the haem-containing chains [Suzuki, Takagi & Ohta (1988) Biochem. J. 255, 541-545]. The tube-worm haemoglobins are believed to have a function of transporting sulphide (H2S) to internal bacterial symbionts, as well as of facilitating O2 transport [Arp & Childress (1983) Science 219, 295-297]. We have determined the complete amino acid sequence of Lamellibrachia chain AIII by automated or manual Edman sequencing. The chain is composed of 144 amino acid residues, has three cysteine residues at positions 3, 74 and 133, and has a molecular mass of 16,620 Da, including a haem group. The sequence showed significant homology (30-50% identity) with those of haem-containing chains of annelid giant haemoglobins. Two of the three cysteine residues are located at the positions where an intrachain disulphide bridge is formed in all annelid chains, but the remaining one (Cys-74) was located at a unique position, compared with annelid chains. Since the chain AIII was shown to have a reactive thiol group in the intact 3000 kDa molecule by preliminary experiments, the cysteine residue at position 74 appears to be one of the most probable candidates for the sulphide-binding sites. A phylogenetic tree was constructed from nine chains of annelid giant haemoglobins and one chain of vestimentiferan tube-worm haemoglobin now determined. The tree clearly showed that Lamellibrachia chain AIII belongs to the family of strain A of annelid giant haemoglobins, and that the two classes of Annelida, polychaete and oligochaete, and the vestimentiferan tube worm diverged at almost the same time. H.p.l.c. patterns of peptides (Figs. 4-7), amino acid compositions of peptides (Table 2) and amino acid sequences of

  5. Rubella virion polypeptides

    International Nuclear Information System (INIS)

    Ho-Terry, L.; Cohen, A.

    1982-01-01

    Four polypeptides with molecular weights of 55K, 47K, 45K, and 33K have been resolved by polyacrylamide gel electrophoresis of immune precipitated rubella virus. The 47K and 45K components have similar peptide maps but different isoelectric points so that the same polypeptide may exist in more than one charged form. The 55K and 45K components have similar isoelectric points but different peptide maps showing that similarity of isoelectric point is not evidence of identity. (Author)

  6. Elastomeric polypeptides.

    Science.gov (United States)

    van Eldijk, Mark B; McGann, Christopher L; Kiick, Kristi L; van Hest, Jan C M

    2012-01-01

    Elastomeric polypeptides are very interesting biopolymers and are characterized by rubber-like elasticity, large extensibility before rupture, reversible deformation without loss of energy, and high resilience upon stretching. Their useful properties have motivated their use in a wide variety of materials and biological applications. This chapter focuses on elastin and resilin - two elastomeric biopolymers - and the recombinant polypeptides derived from them (elastin-like polypeptides and resilin-like polypeptides). This chapter also discusses the applications of these recombinant polypeptides in the fields of purification, drug delivery, and tissue engineering.

  7. Design of a Software for Calculating Isoelectric Point of a Polypeptide According to Their Net Charge Using the Graphical Programming Language LabVIEW

    Science.gov (United States)

    Tovar, Glomen

    2018-01-01

    A software to calculate the net charge and to predict the isoelectric point (pI) of a polypeptide is developed in this work using the graphical programming language LabVIEW. Through this instrument the net charges of the ionizable residues of the chains of the proteins are calculated at different pH values, tabulated, pI is predicted and an Excel…

  8. Going Beyond the Point Nucleus Approximation to Satisfy the Hellmann–Feynman Theorem: Born–Oppenheimer H2+ in the Ground State

    International Nuclear Information System (INIS)

    Gutlé, Claudine

    2017-01-01

    Incomplete spaces are investigated for solving the Schrödinger equation under the Born–Oppenheimer approximation. It is shown that the Hellmann–Feynman theorem cannot be used for computing the electronic force exerted on a nucleus, when a variational wavefunction with floating centers is used, if multicenter polynomial components are added in order to describe the polarization effects through the chemical bond. This is because the minimum of the potential energy surface is not a stationary point in the direction of the float parameter. Such a failure can be fixed by considering a molecular model with finite size nuclei, as defined herein. The classical electronic force is computed for that model, as compared with the standard point charge approximation, and it is applied to the H 2 + molecular ion. As a result, the former model is found more accurate by several orders of magnitude. (author)

  9. H2 blockers

    Science.gov (United States)

    Peptic ulcer disease - H2 blockers; PUD - H2 blockers; Gastroesophageal reflux - H2 blockers; GERD - H2 blockers ... provider about your symptoms. If you have a peptic ulcer, your provider may prescribe H2 blockers along with ...

  10. Van der Waals bond in dimers: H2Ne, H2Ar, H2Kr

    International Nuclear Information System (INIS)

    Waaijer, M.

    1981-01-01

    The H 2 -inert gas dimers H 2 X, and particularly H 2 Ne, H 2 Ar and H 2 Kr, form the subject of this thesis and are loosely bound van der Waals complexes, which is reflected in the low number of bound states and the small anisotropic interaction. The H 2 X dimers studied are formed in a supersonic nozzle expansion, in which the internal energy is converted into the macroscopic flow energy, establishing an internal temperature drop to 3 K, which favours dimer formation. Because of this cooling the H 2 X dimers relax to the lowest rotational states. The hyperfine transitions have been measured using magnetic beam resonance and yield information about the isotropic as well as the anisotropic intermolecular potential in the range between the classical turning points and in the adjacent part of the repulsive branch. The sensitivity of the method is very high and slight changes in the intermolecular potential cause significant effects. The analysis of the measured hyperfine transitions incorporates all interacting states of the molecule, bound as well as unbound (continuum) states. For H 2 Ne, which is the best studied H 2 -inert gas system from the experimental point of view, the author succeeded in establishing an intermolecular potential, that provides a solid ground for comparison with future ab initio calculations. (Auth.)

  11. Ca(AlH4)2, CaAlH5, and CaH2+6LiBH4 : Calculated dehydrogenation enthalpy, including zero point energy, and the structure of the phonon spectra

    NARCIS (Netherlands)

    Marashdeh, A.; Frankcombe, T.J.

    2008-01-01

    The dehydrogenation enthalpies of Ca(AlH4)2, CaAlH5, and CaH2+6LiBH4 have been calculated using density functional theory calculations at the generalized gradient approximation level. Harmonic phonon zero point energy (ZPE) corrections have been included using Parlinski’s direct method. The

  12. Modeling Water Saturation Points in Natural Gas Streams Containing CO2 and H2S-Comparisons with Different Equations of State

    DEFF Research Database (Denmark)

    dos Santos, Leticia C.; Abunahman, Samir S.; Tavares, Frederico W.

    2015-01-01

    Since the discovery of the Pre-Salt layer in Brazilian waters, production of high gas-oil ratio (GOR) has increased considerably. This gas has a high content of water, CO2, and sometimes H2S. A study in different conditions was conducted using several equations of state (EoS) such as Peng......-Robinson, GERG-modified Peng-Robinson (PR-ISO-04), Soave-Redlich-Kwong, and Cubic Plus Association (CPA). Petrobras Process Simulator has been used to perform the phase equilibrium calculations. All the EoS except for CPA used parameters from the literature. A new parameter estimation procedure for CPA has been...

  13. Accurate approach for determining fresh-water carbonate (H2CO3(*)) alkalinity, using a single H3PO4 titration point.

    Science.gov (United States)

    Birnhack, Liat; Sabach, Sara; Lahav, Ori

    2012-10-15

    A new, simple and accurate method is introduced for determining H(2)CO(3)(*) alkalinity in fresh waters dominated by the carbonate weak-acid system. The method relies on a single H(3)PO(4) dosage and two pH readings (acidic pH value target: pH~4.0). The computation algorithm is based on the concept that the overall alkalinity mass of a solution does not change upon the addition of a non-proton-accepting species. The accuracy of the new method was assessed batch-wise with both synthetic and actual tap waters and the results were compared to those obtained from two widely used alkalinity analysis methods (titration to pH~4.5 and the Gran titration method). The experimental results, which were deliberately obtained with simple laboratory equipment (glass buret, general-purpose pH electrode, magnetic stirrer) proved the method to be as accurate as the conventional methods at a wide range of alkalinity values (20-400 mg L(-1) as CaCO(3)). Analysis of the relative error attained in the proposed method as a function of the target (acidic) pH showed that at the range 4.0pHalkalinity measurement is also described. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Fast and highly sensitive fiber-enhanced Raman spectroscopic monitoring of molecular H2 and CH4 for point-of-care diagnosis of malabsorption disorders in exhaled human breath.

    Science.gov (United States)

    Hanf, Stefan; Bögözi, Timea; Keiner, Robert; Frosch, Torsten; Popp, Jürgen

    2015-01-20

    Breath gas analysis is a novel powerful technique for noninvasive, early-stage diagnosis of metabolic disorders or diseases. Molecular hydrogen and methane are biomarkers for colonic fermentation, because of malabsorption of oligosaccharides (e.g., lactose or fructose) and for small intestinal bacterial overgrowth. Recently, the presence of these gases in exhaled breath was also correlated with obesity. Here, we report on the highly selective and sensitive detection of molecular hydrogen and methane within a complex gas mixture (consisting of H2, CH4, N2, O2, and CO2) by means of fiber-enhanced Raman spectroscopy (FERS). An elaborate FERS setup with a microstructured hollow core photonic crystal fiber (HCPCF) provided a highly improved analytical sensitivity. The simultaneous monitoring of H2 with all other gases was achieved by a combination of rotational (H2) and vibrational (other gases) Raman spectroscopy within the limited spectral transmission range of the HCPCF. The HCPCF was combined with an adjustable image-plane aperture pinhole, in order to separate the H2 rotational Raman bands from the silica background signal and improve the sensitivity down to a limit of detection (LOD) of 4.7 ppm (for only 26 fmol H2). The ability to monitor the levels of H2 and CH4 in a positive hydrogen breath test (HBT) was demonstrated. The FERS sensor possesses a high dynamic range (∼5 orders of magnitude) with a fast response time of few seconds and provides great potential for miniaturization. We foresee that this technique will pave the way for fast, noninvasive, and painless point-of-care diagnosis of metabolic diseases in exhaled human breath.

  15. Passivity of AISI 321 stainless steel in 0.5 M H2SO4 solution studied by Mott–Schottky analysis in conjunction with the point defect model

    Directory of Open Access Journals (Sweden)

    A. Fattah-alhosseini

    2016-11-01

    Full Text Available The passivity of AISI 321 stainless steel in 0.5 M H2SO4 solution, in the steady-state condition, has been explored using electrochemical impedance spectroscopy (EIS and Mott–Schottky analysis. Based on the Mott–Schottky analysis in conjunction with the point defect model (PDM, it was shown that the calculated donor density decreases exponentially with increasing passive film formation potential. The thickness of the passive film was increased linearly with the formation potential. These observations were consistent with the predictions of the PDM, noting that the point defects within the passive film are metal interstitials, oxygen vacancies, or both.

  16. Chemical Reaction Rates from Ring Polymer Molecular Dynamics: Zero Point Energy Conservation in Mu + H2 → MuH + H.

    Science.gov (United States)

    Pérez de Tudela, Ricardo; Aoiz, F J; Suleimanov, Yury V; Manolopoulos, David E

    2012-02-16

    A fundamental issue in the field of reaction dynamics is the inclusion of the quantum mechanical (QM) effects such as zero point energy (ZPE) and tunneling in molecular dynamics simulations, and in particular in the calculation of chemical reaction rates. In this work we study the chemical reaction between a muonium atom and a hydrogen molecule. The recently developed ring polymer molecular dynamics (RPMD) technique is used, and the results are compared with those of other methods. For this reaction, the thermal rate coefficients calculated with RPMD are found to be in excellent agreement with the results of an accurate QM calculation. The very minor discrepancies are within the convergence error even at very low temperatures. This exceptionally good agreement can be attributed to the dominant role of ZPE in the reaction, which is accounted for extremely well by RPMD. Tunneling only plays a minor role in the reaction.

  17. Gastric inhibitory polypeptide analogues

    DEFF Research Database (Denmark)

    Holst, Jens Juul

    2002-01-01

    Gastric inhibitory polypeptide (GIP, also called glucose-dependent insulinotropic polypeptide) and glucagon-like peptide-1 (GLP-1) are peptide hormones from the gut that enhance nutrient-stimulated insulin secretion (the 'incretin' effect). Judging from experiments in mice with targeted deletions...

  18. H2@Scale Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ruth, Mark

    2017-07-12

    'H2@Scale' is a concept based on the opportunity for hydrogen to act as an intermediate between energy sources and uses. Hydrogen has the potential to be used like the primary intermediate in use today, electricity, because it too is fungible. This presentation summarizes the H2@Scale analysis efforts performed during the first third of 2017. Results of technical potential uses and supply options are summarized and show that the technical potential demand for hydrogen is 60 million metric tons per year and that the U.S. has sufficient domestic resources to meet that demand. A high level infrastructure analysis is also presented that shows an 85% increase in energy on the grid if all hydrogen is produced from grid electricity. However, a preliminary spatial assessment shows that supply is sufficient in most counties across the U.S. The presentation also shows plans for analysis of the economic potential for the H2@Scale concept. Those plans involve developing supply and demand curves for potential hydrogen generation options and as compared to other options for use of that hydrogen.

  19. H2 Reconstitution

    Science.gov (United States)

    2002-02-01

    AFRL-DE-TR-2002-1033 AFRL-DE-TR- 2002-1033 H2 RECONSTITUTION Mike Skipper et al. ASR Corporation 7817 Bursera NW Albuquerque, NM 87120 February 2002...PERFORMING ORGANIZATION REPORT NUMBER ASR Corporation 7817 Bursera NW Albuquerque, NM 87120 DC-TR-0328.008-1 9. SPONSORING / MONITORING AGENCY NAME...Albuquerque, NM 87110 1 cy ASR Corporation 7817 Bursera NW Albuquerque, NM 87120 1 cy Jeff Berger AFRL/DEHP Kirtland AFB, NM 87117 1 cy Tyrone Tran AFRL/DEHP Kirtland AFB, NM 87117 1 cy 40

  20. Stratospheric H2O

    International Nuclear Information System (INIS)

    Ellsaesser, H.W.

    1979-01-01

    Documentation of the extreme aridity (approx. 3% relative humidity) of the lower stratosphere and the rapid decrease of mixing ratio with height just above the polar tropopause (20-fold in the 1st km) was begun by Dobson et al., (1946) in 1943. They recognized that this extreme and persistent aridity must be dynamically maintained else it would have been wiped out by turbulent diffusion. This led Brewer (1949) to hypothesize a stratospheric circulation in which all air enters through the tropical tropopause where it is freeze dried to a mass mixing ratio of 2 to 3 ppM. This dry air then spreads poleward and descends through the polar tropopauses overpowering upward transport of water vapor by diffusion which would otherwise be permitted by the much warmer temperatures of the polar tropopauses. Questions can indeed be raised as to the absolute magnitudes of stratospheric mixing ratios, the effective temperature of the tropical tropopause cold trap, the reality of winter pole freeze-dry sinks and the representativeness of the available observations suggesting an H 2 O mixing ratio maximum just above the tropical tropopause and a constant mixing ratio from the tropopause to 30 to 35 km. However, no model that better fits all of the available data is available, than does the Brewer (1949) hypothesis coupled with a lower stratosphere winter pole, freeze-dry sink, at least over Antarctica

  1. Prebiotic polynucleotides and polypeptides

    Science.gov (United States)

    Orgel, L. E.

    1975-01-01

    Work on the nonenzymatic replication of polynucleotides is discussed emphasizing sequence dependence and showing that alternating polynucleotides should replicate more easily than any others. Experimental work is described showing that polypeptides in which hydrophobic and hydrophilic residues alternate, adopt a beta structure in aqueous solution. The possible relevance of these observations for the evolution of the genetic code is given.

  2. Hydrogen Dynamics in Cyanobacteria Dominated Microbial Mats Measured by Novel Combined H2/H2S and H2/O2 Microsensors

    Directory of Open Access Journals (Sweden)

    Karen Maegaard

    2017-10-01

    Full Text Available Hydrogen may accumulate to micromolar concentrations in cyanobacterial mat communities from various environments, but the governing factors for this accumulation are poorly described. We used newly developed sensors allowing for simultaneous measurement of H2S and H2 or O2 and H2 within the same point to elucidate the interactions between oxygen, sulfate reducing bacteria, and H2 producing microbes. After onset of darkness and subsequent change from oxic to anoxic conditions within the uppermost ∼1 mm of the mat, H2 accumulated to concentrations of up to 40 μmol L-1 in the formerly oxic layer, but with high variability among sites and sampling dates. The immediate onset of H2 production after darkening points to fermentation as the main H2 producing process in this mat. The measured profiles indicate that a gradual disappearance of the H2 peak was mainly due to the activity of sulfate reducing bacteria that invaded the formerly oxic surface layer from below, or persisted in an inactive state in the oxic mat during illumination. The absence of significant H2 consumption in the formerly oxic mat during the first ∼30 min after onset of anoxic conditions indicated absence of active sulfate reducers in this layer during the oxic period. Addition of the methanogenesis inhibitor BES led to increase in H2, indicating that methanogens contributed to the consumption of H2. Both H2 formation and consumption seemed unaffected by the presence/absence of H2S.

  3. Further investigations on the polypeptides and reconstitution of prasinophycean ejectisomes.

    Science.gov (United States)

    Ammermann, Silke; Hillebrand, Helmut; Rhiel, Erhard

    2014-06-01

    Ejectisome fragments were isolated from the prasinophyte Pyramimonas grossii and subjected to different treatments, i.e. Percoll density gradient centrifugation, incubation at pH 2.5 or at pH 10.8, or incubation in 6M guanidine hydrochloride. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed that Percoll density gradient centrifugation did not improve the purity of the ejectisome fragment-enriched fractions. The ejectisome fragments withstood pH 2.5 and pH 10.8 treatment, and no loosely bound polypeptides became detached. The disintegration of ejectisome fragments was achieved in 6M guanidine hydrochloride, and reassembly into filamentous, ejectisome-like structures occurred after dialysis against distilled water. Fractions enriched either in ejectisome fragments or in reconstituted ejectisome-like structures were dominated by three polypeptides with relative molecular weights of approximately 12.5-19kDa and two additional polypeptides of 23 and 26kDa. A polyclonal antiserum directed against an ejectisome fragment-enriched fraction weakly cross-reacted with these polypeptides, and no significant immuno-labelling of ejectisome fragments was registered. A positive immuno-label was achieved using immunoglobulin (IgG) fractions which were gained by selectively incubating nitrocellulose stripes of these polypeptides with the antiserum. Copyright © 2014 Elsevier GmbH. All rights reserved.

  4. Mosaic HIV envelope immunogenic polypeptides

    Energy Technology Data Exchange (ETDEWEB)

    Korber, Bette T. M.; Gnanakaran, S.; Perkins, Simon; Sodroski, Joseph; Haynes, Barton

    2018-01-02

    Disclosed herein are mosaic HIV envelope (Env) polypeptides that can elicit an immune response to HIV (such as cytotoxic T cell (CTL), helper T cell, and/or humoral responses). Also disclosed are sets of the disclosed mosaic Env polypeptides, which include two or more (for example, three) of the polypeptides. Also disclosed herein are methods for treating or inhibiting HIV in a subject including administering one or more of the disclosed immunogenic polypeptides or compositions to a subject infected with HIV or at risk of HIV infection. In some embodiments, the methods include inducing an immune response to HIV in a subject comprising administering to the subject at least one (such as two, three, or more) of the immunogenic polypeptides or at least one (such as two, three, or more) nucleic acids encoding at least one of the immunogenic polypeptides disclosed herein.

  5. H2@Scale Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    Pivovar, Bryan

    2017-03-31

    Final report from the H2@Scale Workshop held November 16-17, 2016, at the National Renewable Energy Laboratory in Golden, Colorado. The U.S. Department of Energy's National Renewable Energy Laboratory hosted a technology workshop to identify the current barriers and research needs of the H2@Scale concept. H2@Scale is a concept regarding the potential for wide-scale impact of hydrogen produced from diverse domestic resources to enhance U.S. energy security and enable growth of innovative technologies and domestic industries. Feedback received from a diverse set of stakeholders at the workshop will guide the development of an H2@Scale roadmap for research, development, and early stage demonstration activities that can enable hydrogen as an energy carrier at a national scale.

  6. Zeolite encapsulation of H2

    International Nuclear Information System (INIS)

    Cooper, S.; Lakner, J.F.

    1982-08-01

    Experiments with H 2 have shown that it is possible to encapsulate gases in the structure of certain molecular sieves. This method may offer a better means of temporarily storing and disposing of tritium over some others presently in use. The method may also prove safer, and may enable isotope separation, and removal of 3 He. Initial experiments were performed with H 2 to screen potential candidates for use with tritium

  7. Radiolysis of polypeptide

    International Nuclear Information System (INIS)

    Ogura, Isao; Nakamura, Katsuichi; Tanaka, Hiroshi; Takahashi, Katsuhiro; Ozaki, Makoto

    1981-01-01

    Almost the same results were obtained from the additional dipeptide, Gly-DL-Ala and DL-Ala-DL-Phe, by the γ-irradiation as previous report. Tri and tetrapeptide consisted of the same amino acid signified good stability than the others. Every polypeptide composed from sulfur contained amino acid exhaled the smell of hydrogen sulfide by the irradiation. It seemed that the stability by the difference of position of amino group in amino acid increased in order α, β, γ ... amino acid and that by the existence of hydroxyl group became smaller. (author)

  8. Development of Elastomeric Polypeptide BIomaterials

    National Research Council Canada - National Science Library

    Urry, Dan

    1998-01-01

    To design elastic polypeptide biomaterials in order to achieve diverse forms of free energy transduction by these water-miscible hydrophobic folding and assembling macromolecules, thereby to elucidate...

  9. Biomedical applications of polypeptide multilayer nanofilms and microcapsules

    Science.gov (United States)

    Rudra, Jai Simha S.

    The past few years have witnessed considerable growth in synthetic polymer chemistry and physics, biomaterials science, and nano-scale engineering. Research on polypeptide multilayer films, coatings, and microcapsules is located at the intersection of these areas and are promising materials for applications in medicine, biotechnology, environmental science. Most envisioned applications of polypeptide multilayers have a biomedical bent. This dissertation on polypeptide multilayer film applications covers key points of polypeptides as materials, means of polymer production, film preparation, film characterization methods, and key points of current research in basic science. Both commercial and designed peptides have been used to fabricate films for in-vitro applications such as antimicrobial coatings and cell culture coatings and also microcapsules for drug delivery applications. Other areas of product development include artificial red blood cells, anisotropic coatings, enantioselective membranes, and artificial viruses.

  10. Thermodynamic and transport properties of frozen and reacting pH2-oH2 mixtures

    Science.gov (United States)

    Carter, H. G.; Bullock, R. E.

    1972-01-01

    Application of experimental state data and spectroscopic term values shows that the thermodynamic and transport properties of reacting pH2-oH2 mixtures are considerably different than those of chemically frozen pH2 at temperatures below 300 R. Calculated H-S data also show that radiation-induced pH2-oH2 equilibration at constant enthalpy produces a temperature drop of at least 28 R, corresponding to an ideal shaft work loss of 15% or more for a turbine operating downstream from the point of conversion. Aside from differences in thermodynamic and transport properties, frozen pH2-oH2 mixtures may differ from pure pH2 on a purely hydrodynamical basis.

  11. Ebrotidina: nuevo antagonista H2

    Directory of Open Access Journals (Sweden)

    Noel Padrón Pérez

    1999-01-01

    Full Text Available Se realizó una revisión bibliográfica sobre un nuevo antagonista H2, la ebrotidina, que exhibe ventajas con respecto a otros medicamentos antisecretores. Las propiedades gastroprotectoras y la actividad anti H. pylori del fármaco, en el tratamiento de la enfermedad péptica ulcerosa, se mencionan en el presente trabajo.A bibliographic review on the new H2 antagonist, ebrotidine, that presents advantages in comparison with other antisecretory drugs, is made. The gastroprotective properties and the anti H. pylori activity of the drug in the treatment of peptic ulcer are mentioned in this paper.

  12. A clustered H2 beam

    International Nuclear Information System (INIS)

    Marcri, M.

    1984-01-01

    This chapter discusses the construction of a clustered H2 beam to obtain - pp interactions using the p beam produced in A.A. and stored via P.S. in ring 2 of ISR in order to perform an experimental study of charmonium states (experiment R 704 at the CERN ISR). Topics covered include the choice of the nozzle, the H2 injection circuit, the pumping system, measurement and controls, and actual status. A luminosity of 10 31 cm -2 sec -1 can be achieved using a circulating beam of 3x10 11- p and a target of H2 1.75x10 -10 g/cm 2 thick. The use of converging-diverging nozzles is effective for the production of very intense beams of clusters of H2 molecules. Differential pumping stages are needed to keep the pressure in the ISR ring down to acceptable values for the operation of the machine (pumping system of the ISR, beam lifetime, signal to noise ratio)

  13. H2O solubility in basalt at upper mantle conditions

    Science.gov (United States)

    Mitchell, Alexandra L.; Gaetani, Glenn A.; O'Leary, Julie A.; Hauri, Erik H.

    2017-10-01

    This study presents a new experimental approach for determining H2O solubility in basaltic melt at upper mantle conditions. Traditional solubility experiments are limited to pressures of 600 MPa or less because it is difficult to reliably quench silicate melts containing greater than 10 wt% dissolved H2O. To overcome this limitation, our approach relies on the use of secondary ion mass spectrometry to measure the concentration of H dissolved in olivine and on using the measured H in olivine as a proxy for the concentration of H2O in the co-existing basaltic melt. The solubility of H2O in the melt is determined by performing a series of experiments at a single pressure and temperature with increasing amounts of liquid H2O added to each charge. The point at which the concentration of H in the olivine first becomes independent of the amount of initial H2O content of the charge (added + adsorbed H2O) indicates its solubility in the melt. Experiments were conducted by packing basalt powder into a capsule fabricated from San Carlos olivine, which was then pressure-sealed inside a Ni outer capsule. Our experimental results indicate that at 1000 MPa and 1200 °C, the solubility of H2O in basaltic melt is 20.6 ± 0.9 wt% (2 × standard deviation). This concentration is considerably higher than predicted by most solubility models but defines a linear relationship between H2O fugacity and the square of molar H2O solubility when combined with solubility data from lower pressure experiments. Further, our solubility determination agrees with melting point depression determined experimentally by Grove et al. (2006) for the H2O-saturated peridotite solidus at 1000 MPa. Melting point depression calculations were used to estimate H2O solubility in basalt along the experimentally determined H2O-saturated peridotite solidus. The results suggest that a linear relationship between H2O fugacity and the square of molar solubility exists up to 1300 MPa, where there is an inflection point

  14. The H2O2-H2O Hypothesis: Extremophiles Adapted to Conditions on Mars?

    Science.gov (United States)

    Houtkooper, Joop M.; Schulze-Makuch, Dirk

    2007-08-01

    The discovery of extremophiles on Earth is a sequence of discoveries of life in environments where it had been deemed impossible a few decades ago. The next frontier may be the Martian surface environment: could life have adapted to this harsh environment? What we learned from terrestrial extremophiles is that life adapts to every available niche where energy, liquid water and organic materials are available so that in principle metabolism and propagation are possible. A feasible adaptation mechanism to the Martian surface environment would be the incorporation of a high concentration of hydrogen peroxide in the intracellular fluid of organisms. The H2O2-H2O hypothesis suggests the existence of Martian organisms that have a mixture of H2O2 and H2O instead of salty water as their intracellular liquid (Houtkooper and Schulze-Makuch, 2007). The advantages are that the freezing point is low (the eutectic freezes at 56.5°C) and that the mixture is hygroscopic. This would enable the organisms to scavenge water from the atmosphere or from the adsorbed layers of water molecules on mineral grains, with H2O2 being also a source of oxygen. Moreover, below its freezing point the H2O2-H2O mixture has the tendency to supercool. Hydrogen peroxide is not unknown to biochemistry on Earth. There are organisms for which H2O2 plays a significant role: the bombardier beetle, Brachinus crepitans, produces a 25% H2O2 solution and, when attacked by a predator, mixes it with a fluid containing hydroquinone and a catalyst, which produces an audible steam explosion and noxious fumes. Another example is Acetobacter peroxidans, which uses H2O2 in its metabolism. H2O2 plays various other roles, such as the mediation of physiological responses such as cell proliferation, differentiation, and migration. Moreover, most eukaryotic cells contain an organelle, the peroxisome, which mediates the reactions involving H2O2. Therefore it is feasible that in the course of evolution, water-based organisms

  15. Galanin and vasoactive intestinal polypeptide

    DEFF Research Database (Denmark)

    Harling, H; Messell, T; Poulsen, Steen Seier

    1991-01-01

    By immunohistochemistry and double staining technique, almost complete coexistence of galanin-like immunoreactivity (GAL-LI) and vasoactive intestinal polypeptide-like immunoreactivity (VIP-LI) was demonstrated in submucosal ganglionic cells and mucosal nerve fibers of the porcine ileum. The rele......By immunohistochemistry and double staining technique, almost complete coexistence of galanin-like immunoreactivity (GAL-LI) and vasoactive intestinal polypeptide-like immunoreactivity (VIP-LI) was demonstrated in submucosal ganglionic cells and mucosal nerve fibers of the porcine ileum...

  16. Surface active complexes formed between keratin polypeptides and ionic surfactants.

    Science.gov (United States)

    Pan, Fang; Lu, Zhiming; Tucker, Ian; Hosking, Sarah; Petkov, Jordan; Lu, Jian R

    2016-12-15

    Keratins are a group of important proteins in skin and hair and as biomaterials they can provide desirable properties such as strength, biocompatibility, and moisture regaining and retaining. The aim of this work is to develop water-soluble keratin polypeptides from sheep wool and then explore how their surface adsorption behaves with and without surfactants. Successful preparation of keratin samples was demonstrated by identification of the key components from gel electrophoresis and the reproducible production of gram scale samples with and without SDS (sodium dodecylsulphate) during wool fibre dissolution. SDS micelles could reduce the formation of disulphide bonds between keratins during extraction, reducing inter-molecular crosslinking and improving keratin polypeptide solubility. However, Zeta potential measurements of the two polypeptide batches demonstrated almost identical pH dependent surface charge distributions with isoelectric points around pH 3.5, showing complete removal of SDS during purification by dialysis. In spite of different solubility from the two batches of keratin samples prepared, very similar adsorption and aggregation behavior was revealed from surface tension measurements and dynamic light scattering. Mixing of keratin polypeptides with SDS and C 12 TAB (dodecyltrimethylammonium bromide) led to the formation of keratin-surfactant complexes that were substantially more effective at reducing surface tension than the polypeptides alone, showing great promise in the delivery of keratin polypeptides via the surface active complexes. Neutron reflection measurements revealed the coexistence of surfactant and keratin polypeptides at the interface, thus providing the structural support to the observed surface tension changes associated with the formation of the surface active complexes. Copyright © 2016. Published by Elsevier Inc.

  17. Rubella virion polypeptides. Characterization by polyacrylamide gel electrophoresis, isoelectric focusing and peptide mapping

    Energy Technology Data Exchange (ETDEWEB)

    Ho-Terry, L.; Cohen, A. (University Coll. Hospital Medical School, London (UK))

    1982-01-01

    Four polypeptides with molecular weights of 55K, 47K, 45K, and 33K have been resolved by polyacrylamide gel electrophoresis of immune precipitated rubella virus. The 47K and 45K components have similar peptide maps but different isoelectric points so that the same polypeptide may exist in more than one charged form. The 55K and 45K components have similar isoelectric points but different peptide maps showing that similarity of isoelectric point is not evidence of identity.

  18. Glucose-dependent insulinotropic polypeptide

    DEFF Research Database (Denmark)

    Christensen, Mikkel Bring

    2016-01-01

    The hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are secreted by enteroendocrine cells in the intestinal mucosa in response to nutrient ingestion. They are called incretin hormones because of their ability to enhance insulin secretion. However...

  19. Glucose-dependent insulinotropic polypeptide

    DEFF Research Database (Denmark)

    Christensen, Mikkel; Vedtofte, Louise; Holst, Jens Juul

    2011-01-01

    OBJECTIVE To evaluate the glucose dependency of glucose-dependent insulinotropic polypeptide (GIP) effects on insulin and glucagon release in 10 healthy male subjects ([means ± SEM] aged 23 ± 1 years, BMI 23 ± 1 kg/m2, and HbA1c 5.5 ± 0.1%). RESEARCH DESIGN AND METHODS Saline or physiological doses...

  20. Glucose-dependent Insulinotropic Polypeptide

    DEFF Research Database (Denmark)

    Christensen, Mikkel B; Calanna, Salvatore; Holst, Jens Juul

    2014-01-01

    CONTEXT: Patients with type 2 diabetes mellitus (T2DM) have clinically relevant disturbances in the effects of the hormone glucose-dependent insulinotropic polypeptide (GIP). OBJECTIVE: We aimed to evaluate the importance of the prevailing plasma glucose levels for the effect of GIP on responses...

  1. Breakup of H2+ by photon impact

    Science.gov (United States)

    Haxton, Daniel

    2013-05-01

    The photoabsorption cross section of the ground rovibrational state of H2+ is vastly dominated by breakup, i.e. dissociative ionization and dissociative excitation. To this point the breakup cross section had not been calculated in a formally exact ab initio treatment (without any Born-Oppenheimer approximation). Here such calculations are presented; all terms in the exact nonrelativistic Hamiltonian are included along with an exact representation of outgoing flux. The breakup cross section is calculated directly and divided into contributions from dissociative excitation and dissociative ionization channels. Approximate expressions for dissociative ionization that are often used are compared to exact expressions, and the approximate expressions are shown to be remarkably accurate in some cases but deficient in others near onset. See arXiv:1301.0153. Supported by US DOE Basic Energy Sciences Contract DE-AC02-05CH11231.

  2. Methods for using polypeptides having cellobiohydrolase activity

    Science.gov (United States)

    Morant, Marc D; Harris, Paul

    2016-08-23

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  3. Dual function of Swc5 in SWR remodeling ATPase activation and histone H2A eviction.

    Science.gov (United States)

    Sun, Lu; Luk, Ed

    2017-09-29

    The chromatin remodeler SWR deposits histone H2A.Z at promoters and other regulatory sites via an ATP-driven histone exchange reaction that replaces nucleosomal H2A with H2A.Z. Simultaneous binding of SWR to both H2A nucleosome and free H2A.Z induces SWR ATPase activity and engages the histone exchange mechanism. Swc5 is a conserved subunit of the 14-polypeptide SWR complex that is required for the histone exchange reaction, but its molecular role is unknown. We found that Swc5, although not required for substrate binding, is required for SWR ATPase stimulation, suggesting that Swc5 is required to couple substrate recognition to ATPase activation. A biochemical complementation assay was developed to show that a unique, conserved domain at the C-terminus of Swc5, called Bucentaur (BCNT), is essential for the histone exchange activity of SWR, whereas an acidic region at the N-terminus is required for optimal SWR function. In vitro studies showed the acidic N-terminus of Swc5 preferentially binds to the H2A-H2B dimer and exhibits histone chaperone activity. We propose that an auxiliary function of Swc5 in SWR is to assist H2A ejection as H2A.Z is inserted into the nucleosome. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  4. Phycobilisome structure of porphyridium cruentum: polypeptide composition

    Energy Technology Data Exchange (ETDEWEB)

    Redlinger, T.; Gantt, E.

    1981-01-01

    Purified phycobilisomes of porphyridium cruentum were solubilized in sodium dodecyl sulfate and resolved by sodium dodecyl sulfate-acrylamide gel electrophoresis into nine colored and nine colorless polypeptides. The colored polypeptides accounted for about 84% of the total stainable protein, and the colorless polypeptides accounted for the remaining 16%. Five of the colored polypeptides ranging in molecular weight from 13,300 to 19,500 were identified as the ..cap alpha.. and ..beta.. subunits of allophycocyanin, R-phycocyanin, and phycoerythrin. Three others (29,000-30,500) were orange and are probably related to the ..gamma.. subunit of phycoerythrin. Sequential dissociation of phycobilisomes, and analysis of the polypeptides in each fraction, revealed the association of a 32,500 molecular weight colorless polypeptide with a phycoerythrin fraction. The remaining eight colorless polypeptides were in the core fraction of the phycobilisome, which also was enriched in allophycocyanin.

  5. Photolysis of H2O-H2O2 Mixtures: The Destruction of H2O2

    Science.gov (United States)

    Loeffler, M. J.; Fama, M.; Baragiola, R. A.; Carlson, R. W.

    2013-01-01

    We present laboratory results on the loss of H2O2 in solid H2O + H2O2 mixtures at temperatures between 21 and 145 K initiated by UV photolysis (193 nm). Using infrared spectroscopy and microbalance gravimetry, we measured the decrease of the 3.5 micrometer infrared absorption band during UV irradiation and obtained a photodestruction cross section that varies with temperature, being lowest at 70 K. We use our results, along with our previously measured H2O2 production rates via ionizing radiation and ion energy fluxes from the spacecraft to compare H2O2 creation and destruction at icy satellites by ions from their planetary magnetosphere and from solar UV photons. We conclude that, in many cases, H2O2 is not observed on icy satellite surfaces because the H2O2 photodestruction rate is much higher than the production rate via energetic particles, effectively keeping the H2O2 infrared signature at or below the noise level.

  6. Dissociative recombination of molecular ions H2+

    International Nuclear Information System (INIS)

    Abarenov, A.V.; Marchenko, V.S.

    1989-01-01

    The total cross sections of dissociation and dissociative recombination of slow electrons and molecular ions H 2 + have been calculated in terms of the quasiclassical and dipole approximations. In the calculations allowance was made for the quantum nature of vibrational motion of heavy particles and presence of autoionization of divergence states of the H 2 (Σ u , nl) molecules. It is shown that the H 2 + ion dissociation cross sections are dominant in increase of the electron energy in the ε >or approx. 2-3 eV region for H 2 + (v) ion distribution over the vibrational levels characteristic for the beam experiments. 15 refs.; 5 figs

  7. H2O2: A Dynamic Neuromodulator

    Science.gov (United States)

    Rice, Margaret E.

    2012-01-01

    Increasing evidence implicates hydrogen peroxide (H2O2) as an intra- and intercellular signaling molecule that can influence processes from embryonic development to cell death. Most research has focused on relatively slow signaling, on the order of minutes to days, via second messenger cascades. However, H2O2 can also mediate subsecond signaling via ion channel activation. This rapid signaling has been examined most thoroughly in the nigrostriatal dopamine (DA) pathway, which plays a key role in facilitating movement mediated by the basal ganglia. In DA neurons of the substantia nigra, endogenously generated H2O2 activates ATP-sensitive K+ (KATP) channels that inhibit DA neuron firing. In the striatum, H2O2 generated downstream from glutamatergic AMPA receptor activation in medium spiny neurons acts as a diffusible messenger that inhibits axonal DA release, also via KATP channels. The source of dynamically generated H2O2 is mitochondrial respiration; thus, H2O2 provides a novel link between activity and metabolism via KATP channels. Additional targets of H2O2 include transient receptor potential (TRP) channels. In contrast to the inhibitory effect of H2O2 acting via KATP channels, TRP channel activation is excitatory. This review describes emerging roles of H2O2 as a signaling agent in the nigrostriatal pathway and other basal ganglia neurons. PMID:21666063

  8. Recombinant expression of backbone-cyclized polypeptides.

    Science.gov (United States)

    Borra, Radhika; Camarero, Julio A

    2013-09-01

    Here we review the different biochemical approaches available for the expression of backbone-cyclized polypeptides, including peptides and proteins. These methods allow for the production of circular polypeptides either in vitro or in vivo using standard recombinant DNA expression techniques. Polypeptide circularization provides a valuable tool to study the effects of topology on protein stability and folding kinetics. Furthermore, having biosynthetic access to backbone-cyclized polypeptides makes the production of genetically encoded libraries of cyclic polypeptides possible. The production of such libraries, which was previously restricted to the domain of synthetic chemistry, now offers biologists access to highly diverse and stable molecular libraries that can be screened using high-throughput methods for the rapid selection of novel cyclic polypeptide sequences with new biological activities. Copyright © 2013 Wiley Periodicals, Inc.

  9. Production of Elastomeric Polypeptides for Materials Characterizations

    National Research Council Canada - National Science Library

    Urry, Dan

    2004-01-01

    .... Specifically, this effort is to provide 100 gram quantities of six and 10 gram quantities of an additional nine elastomeric polypeptides for conventional and specialized materials characterizations...

  10. A family of microbial lysine transporter polypeptides

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention provides a genetically modified microbial cell for production of lysine, comprising a transgene encoding a polypeptide capable of exporting lysine from the cell. The genetically modified microbial cell for production of lysine may be further characterized by genetic modifica......The present invention provides a genetically modified microbial cell for production of lysine, comprising a transgene encoding a polypeptide capable of exporting lysine from the cell. The genetically modified microbial cell for production of lysine may be further characterized by genetic...... a novel family of lysine transporter polypeptides; and the use of said polypeptide to enhance production of extracellular lysine in a microbial cell....

  11. H2-H2O-HI Hydrogen Separation in H2-H2O-HI Gaseous Mixture Using the Silica Membrane

    International Nuclear Information System (INIS)

    Pandiangan, Tumpal

    2002-01-01

    It was evaluated aiming at the application for hydrogen iodide decomposition in the thermochemical lS process. Porous alumina tube having pore size of 0.1 μm was modified by chemical vapor deposition using tetraethoxysilane. The permeance single gas of He, H 2 , and N 2 was measured at 300-600 o C. Hydrogen permeance of the modified membrane at a permeation temperature of 600 o C was about 5.22 x 10 -08 mol/Pa m 2 s, and 3.2 x 10 -09 of using gas mixture of H 2 -H 2 O-HI, where as HI permeances was below 1 x 10 -10 mol/Pa m 2 s. The Hydrogen permeance relative was not changed after 25 hours exposure in a mixture of H 2 -H 2 O-HI gas at the temperature of 450 o C. (author)

  12. Methods for engineering polypeptide variants via somatic hypermutation and polypeptide made thereby

    Science.gov (United States)

    Tsien, Roger Y; Wang, Lei

    2015-01-13

    Methods using somatic hypermutation (SHM) for producing polypeptide and nucleic acid variants, and nucleic acids encoding such polypeptide variants are disclosed. Such variants may have desired properties. Also disclosed are novel polypeptides, such as improved fluorescent proteins, produced by the novel methods, and nucleic acids, vectors, and host cells comprising such vectors.

  13. Dissociative charge exchange of H2+

    International Nuclear Information System (INIS)

    Bruijn, D. de.

    1983-01-01

    This thesis is devoted to molecular dissociation, in particular the dissociation of the hydrogen molecule H 2 arising from electron capture of its ion H 2 + in a collision. Thereby the important practical question how a chemical bond can be broken is implicitly addressed. This thesis opens (chapter I) with an overview of the available experimental approaches in molecular physics. Further the simple Demkov model for NRCE is described. In chapter II a novel experimental technique for measurements on dissociative processes is introduced which combines a high efficiency with a high energy resolution. A detailed description of the techniques applied in the detector, which has a high spatial and timing resolution with 30 μm and 350 psec FWHM respectively for the detection of one particle, is given in chapter III. A semi-classical theory for NRCE in the medium energy range between a diatomic molecular ion and an atom is developed in chapter IV. The experiments on dissociative charge exchange of H 2 + with Ar, Mg, Na and Cs targets at keV energies are described in Chapter V. The predissociation of the c 3 PIsub(u)-state of H 2 populated after charge exchange of H 2 with several targets at keV energies; is the subject of chapter VI. In chapter VII, orientational oscillations in the cross section for charge exchange of H 2 + with alkali targets are discussed. The last chapter deals with predissociation of highly excited states in H 2 . (Auth.)

  14. Ordered biological nanostructures formed from chaperonin polypeptides

    Science.gov (United States)

    Trent, Jonathan D. (Inventor); McMillan, R. Andrew (Inventor); Kagawa, Hiromi (Inventor); Paavola, Chad D. (Inventor)

    2010-01-01

    The following application relates to nanotemplates, nanostructures, nanoarrays and nanodevices formed from wild-type and mutated chaperonin polypeptides, methods of producing such compositions, methods of using such compositions and particular chaperonin polypeptides that can be utilized in producing such compositions.

  15. Atmospheric photochemical loss of H and H2 from formaldehyde

    DEFF Research Database (Denmark)

    Simonsen, Jens Bæk; Rusteika, Nerijus; Johnson, Matthew Stanley

    2008-01-01

    We have performed ab initio calculations to examine the potential energy along the normal modes of ground-state HCHO and along the reaction coordinates for loss of H2 and atomic hydrogen, respectively. This exploration showed that there are no specific features that will lead to reaction on the e......We have performed ab initio calculations to examine the potential energy along the normal modes of ground-state HCHO and along the reaction coordinates for loss of H2 and atomic hydrogen, respectively. This exploration showed that there are no specific features that will lead to reaction...... on the excited-state surfaces for excitations that are relevant to the troposphere and stratosphere. The calculations did however lead to the localization of a conical intersection point through which a specific loss of H2 could take place. However, the conical intersection lies at 5.4 eV relative to the ground...

  16. Polypeptides having catalase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ye; Duan, Junxin; Zhang, Yu; Tang, Lan

    2017-05-02

    Provided are isolated polypeptides having catalase activity and polynucleotides encoding the polypeptides. Also provided are nucleic acid constructs, vectors and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  17. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Science.gov (United States)

    Spodsberg, Nikolaj

    2015-07-14

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  18. Hybrid polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ye; Shaghasi, Tarana

    2016-11-01

    The present invention provides hybrid polypeptides having cellobiohydrolase activity. The present invention also provides polynucleotides encoding the hybrid polypeptides; nucleic acid constructs, vectors and host cells comprising the polynucleotides; and processes of using the hybrid polypeptides.

  19. Polypeptides having beta-xylosidase activity and polynucleotides encoding same

    Science.gov (United States)

    Liu, Ye; Tang, Lan; Zhang, Yu; Duan, Junxin

    2017-04-18

    Provided are isolated polypeptides having beta-xylosidase activity and polynucleotides encoding the polypeptides. Also provided are nucleic acid constructs, vectors and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  20. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ye; Duan, Junxin; Zhang, Yu; Tang, Lan

    2017-09-26

    Provided are isolated polypeptides having beta-glucosidase activity and polynucleotides encoding the polypeptides. Also provided are nucleic acid constructs, vectors and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  1. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj

    2016-06-28

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  2. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj

    2016-12-13

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  3. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj

    2017-11-21

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  4. Polypeptides having endoglucanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Liu, Ye; Duan, Junxin; Tang, Lan

    2017-07-18

    Provided are isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. Also provided are nucleic acid constructs, vectors and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  5. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Science.gov (United States)

    Spodsberg, Nikolaj

    2015-11-17

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  6. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Tang, Lan; Henriksen, Svend Hostgaard Bang

    2016-05-17

    The present invention provides isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also provides nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  7. Polypeptides having xylanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj

    2017-05-02

    The present invention relates to isolated polypeptides having xylanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  8. Polypeptides having cellobiohydrolase activitiy and polynucleotides encoding same

    Science.gov (United States)

    Liu, Ye; Tang, Lan; Duan, Junxin

    2015-12-15

    The present invention provides isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also provides nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  9. Polypeptides having xylanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj

    2018-02-06

    The present invention relates to isolated polypeptides having xylanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  10. Variations in H2O+/H2O ratios toward massive star-forming regions

    NARCIS (Netherlands)

    Wyrowski, F.; van der Tak, F.; Herpin, F.; Baudry, A.; Bontemps, S.; Chavarria, L.; Frieswijk, W.; Jacq, T.; Marseille, M.; Shipman, R.; van Dishoeck, E.F.; Benz, A.O.; Caselli, P.; Hogerheijde, M.R.; Johnstone, D.; Liseau, R.; Bachiller, R.; Benedettini, M.; Bergin, E.; Bjerkeli, P.; Blake, G.; Braine, J.; Bruderer, S.; Cernicharo, J.; Codella, C.; Daniel, F.; Di Giorgio, A.M.; Dominik, C.; Doty, S.D.; Encrenaz, P.; Fich, M.; Fuente, A.; Giannini, T.; Goicoechea, J.R.; de Graauw, T.; Helmich, F.; Herczeg, G.J.; Jørgensen, J.K.; Kristensen, L.E.; Larsson, B.; Lis, D.; McCoey, C.; Melnick, G.; Nisini, B.; Olberg, M.; Parise, B.; Pearson, J.C.; Plume, R.; Risacher, C.; Santiago, J.; Saraceno, P.; Tafalla, M.; van Kempen, T.A.; Visser, R.; Wampfler, S.; Yıldız, U.A.; Black, J.H.; Falgarone, E.; Gerin, M.; Roelfsema, P.; Dieleman, P.; Beintema, D.; de Jonge, A.; Whyborn, N.; Stutzki, J.; Ossenkopf, V.

    2010-01-01

    Early results from the Herschel Space Observatory revealed the water cation H2O+ to be an abundant ingredient of the interstellar medium. Here we present new observations of the H2O and H2O+ lines at 1113.3 and 1115.2 GHz using the Herschel Space Observatory toward a sample of high-mass star-forming

  11. A signaling polypeptide derived from an innate immune adaptor molecule can be harnessed as a new class of vaccine adjuvant.

    Science.gov (United States)

    Kobiyama, Kouji; Takeshita, Fumihiko; Ishii, Ken J; Koyama, Shohei; Aoshi, Taiki; Akira, Shizuo; Sakaue-Sawano, Asako; Miyawaki, Atsushi; Yamanaka, Yuko; Hirano, Hisashi; Suzuki, Koichi; Okuda, Kenji

    2009-02-01

    Modulation of intracellular signaling using cell-permeable polypeptides is a promising technology for future clinical applications. To develop a novel approach to activate innate immune signaling by synthetic polypeptides, we characterized several different polypeptides derived from the caspase recruitment domain (CARD) of IFN-beta promoter stimulator 1, each of which localizes to a different subcellular compartment. Of particular interest was, N'-CARD, which consisted of the nuclear localization signal of histone H2B and the IFN-beta promoter stimulator 1CARD and which localized to the nucleus. This polypeptide led to a strong production of type I IFNs and molecular and genetic analyses showed that nuclear DNA helicase II is critically involved in this response. N'-CARD polypeptide fused to a protein transduction domain (N'-CARD-PTD) readily transmigrated from the outside to the inside of the cell and triggered innate immune signaling. Administration of N'-CARD-PTD polypeptide elicited production of type I IFNs, maturation of bone marrow-derived dendritic cells, and promotion of vaccine immunogenicity by enhancing Ag-specific Th1-type immune responses, thereby protecting mice from lethal influenza infection and from outgrowth of transplanted tumors in vivo. Thus, our results indicate that the N'-CARD-PTD polypeptide belongs to a new class of vaccine adjuvant that directly triggers intracellular signal transduction by a distinct mechanism from those engaged by conventional vaccine adjuvants, such as TLR ligands.

  12. H2SO4-HNO3-H2O ternary system in the stratosphere

    Science.gov (United States)

    Kiang, C. S.; Hamill, P.

    1974-01-01

    Estimation of the equilibrium vapor pressure over the ternary system H2SO4-HNO3-H2O to study the possibility of stratospheric aerosol formation involving HNO3. It is shown that the vapor pressures for the ternary system H2SO4-HNO3-H2O with weight composition around 70-80% H2SO4, 10-20% HNO3, 10-20% H2O at -50 C are below the order of 10 to the minus 8th mm Hg. It is concluded that there exists more than sufficient nitric acid and water vapor in the stratosphere to participate in ternary system aerosol formation at -50 C. Therefore, HNO3 should be present in stratospheric aerosols, provided that H2SO4 is also present.

  13. H2@Scale Resource and Market Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ruth, Mark

    2017-05-04

    The 'H2@Scale' concept is based on the potential for wide-scale utilization of hydrogen as an energy intermediate where the hydrogen is produced from low cost energy resources and it is used in both the transportation and industrial sectors. H2@Scale has the potential to address grid resiliency, energy security, and cross-sectoral emissions reductions. This presentation summarizes the status of an ongoing analysis effort to quantify the benefits of H2@Scale. It includes initial results regarding market potential, resource potential, and impacts of when electrolytic hydrogen is produced with renewable electricity to meet the potential market demands. It also proposes additional analysis efforts to better quantify each of the factors.

  14. H-2 restriction: Independent recognition of H-2 and foreign antigen by a single receptor

    Science.gov (United States)

    Siliciano, Robert F.; Zacharchuk, Charles M.; Shin, Hyun S.

    1980-01-01

    We describe two situations in which the recognition of hapten can compensate for the lack of recognition of appropriate H-2 gene products in hapten-specific, H-2 restricted, T lymphocyte-mediated cytolysis. First, we show that although recognition of appropriate H-2 gene products is essential for the lysis of target cells bearing a low hapten density, significant hapten-specific lysis of H-2 inappropriate target cells is observed at high levels of target cell derivatization. Secondly, we show that hapten-conjugated anti-H-2 antibody inhibits cytolysis poorly even though its binding to target cell H-2 antigens is equivalent to that of underivatized antibody. These results suggest that hapten and H-2 are recognized independently and are therefore inconsistent with the altered-self model. Although our data do not exclude the dual-recognition model, we prefer to interpret them within the framework of a single-receptor model in which hapten and H-2 are recognized independently by receptors of identical idiotype on the T cell. We postulate that the affinity of these receptors for the relevant H-2 gene product is low enough so that the T cell is not activated by encounters with normal-self cells expressing that H-2 gene product. However, when self cells express in addition a foreign antigen that can also be recognized by the same receptor, then the force of T cell-target cell interaction may be increased sufficiently to activate T cell effector function. PMID:6966404

  15. Preparation of polypeptides comprising multiple TAA peptides.

    Science.gov (United States)

    Ni, Bing; Jia, Zhengcai; Wu, Yuzhang

    2014-01-01

    Polypeptides consisting of multiple tumor-associated antigen epitopes (multiepitope peptides) are commonly used as therapeutic peptide cancer vaccines in experimental studies and clinical trials. These methods include polypeptides composed of multiple major histocompatibility complex (MHC) class I-restricted cytotoxic T cell (CTL) epitopes and those containing multiple CTL epitopes and one T helper (Th) epitope. This chapter describes a complete set of methods for preparing multiepitope peptides and branched multiple antigen peptides (MAPs), including sequence design, peptide synthesis, purification, preservation, and the preparation of polypeptide solutions.

  16. A thermodynamic study of 1-propanol-glycerol-H2O at 25 degrees C: Effect of glycerol on molecular organization of H2O

    DEFF Research Database (Denmark)

    Parsons, M.T.; Westh, Peter; Davies, J.V.

    2001-01-01

    The excess chemical potential, partial molar enthalpy, and volume of 1-propanol were determined in ternary mixtures of 1-propanol-glycerol-H2O at 25degreesC. The mole fraction dependence of all these thermodynamic functions was used to elucidate the effect of glycerol on the molecular organization...... of H2O. The glycerol molecules do not exert a hydrophobic effect on H2O. Rather, the hydroxyl groups of glycerol, perhaps by forming clusters via its alkyl backbone with hydroxyl groups pointing outward, interact with H2O so as to reduce the characteristics of liquid H2O. The global hydrogen bond...... probability and, hence, the percolation nature of the hydrogen bond network is reduced. In addition, the degree of fluctuation inherent in liquid H2O is reduced by glycerol perhaps by participating in the hydrogen bond network via OH groups. At infinite dilution, the pair interaction coefficients in enthalpy...

  17. Methodology Report for H2SModel

    Science.gov (United States)

    2012-01-01

    500 ppm) result in brainstem toxicity leading to cardiorespiratory arrest , myocardial infarction, «knockdown" or sudden loss of consciousness...Performance Seck Treatment Time Litter Time l Time to RTD [ Time to Death ) Figure 1: Overview of H2SModel calculations. cardiopulmonary arrest (see

  18. Fluorescent excitation of interstellar H2

    NARCIS (Netherlands)

    Black, J.H.; Dishoeck, van E.F.

    1987-01-01

    The infrared emission spectrum of H2 excited by ultraviolet absorption, followed by fluorescence, was investigated using comprehensive models of interstellar clouds for computing the spectrum and to assess the effects on the intensity to various cloud properties, such as density, size, temperature,

  19. EPA H2O Software Tool

    Science.gov (United States)

    EPA H2O allows user to: Understand the significance of EGS in Tampa Bay watershed; visually analyze spatial distribution of the EGS in Tampa Bay watershed; obtain map and summary statistics of EGS values in Tampa Bay watershed; analyze and compare potential impacts of development...

  20. Study of the solubility, viscosity and density in Na+, Zn2+/Cl− − H2O, Na+ − Zn2+ − (H2PO2)− − H2O, Na+, Cl−/(H2PO2)− − H2O, and Zn2+, Cl−/(H2PO2)− − H2O ternary systems, and in Na+, Zn2+/Cl−, (H2PO2)−//H2O reciprocal quaternary system at 273.15 K

    International Nuclear Information System (INIS)

    Adiguzel, Vedat; Erge, Hasan; Alisoglu, Vahit; Necefoglu, Hacali

    2014-01-01

    Highlights: • The physicochemical properties of ternary and one quaternary have been studied. • Reciprocal quaternary systems’ solubility and phase equilibrium have been studied. • In all systems the solid phases have been found. • It was found that Zn(H 2 PO 2 ) 2 salt contains 70% of the general crystallization field. - Abstract: The solubility and the physicochemical properties (density, viscosity) in the Na-Zn- Cl-H 2 O), (Na + Zn + H 2 PO 2 + H 2 O), (Na + Cl + H 2 PO 2 + H 2 O), and (Zn + Cl + H 2 PO 2 + H 2 O) ternaries, and in Na + , Zn 2+ /Cl − , (H 2 PO 2 ) − //H 2 O reciprocal quaternary systems at T = 273.15 K were investigated by using the isothermal method. The diagrams of ternary salts systems, (NaCl + ZnCl 2 + H 2 O), (NaCl + NaH 2 PO 2 + H 2 O), (NaH 2 PO 2 + Zn(H 2 PO 2 ) 2 + H 2 O), (ZnCl 2 + Zn(H 2 PO 2 ) 2 + H 2 O), are plotted in figures 1–4. However, whole ions of reciprocal quaternary salt systems are plotted in figure 5. Additionally, the density and viscosity values of ternary systems vs. their corresponding composition values in weight per cent are plotted in figures 6–10. At the (i) (ZnCl 2 + Zn(H 2 PO 2 ) 2 + H 2 O), (ii) (NaCl + ZnCl 2 + H 2 O), (iii) (NaCl + NaH 2 PO 2 + H 2 O), (iv) (NaH 2 PO 2 + Zn(H 2 PO 2 ) 2 + H 2 O) ternary systems the solid phase compositions have been determined as: (i) Zn(H 2 PO 2 ) 2 ⋅ H 2 O, Zn(H 2 PO 2 ) 2 , ZnCl 2 ⋅ 2H 2 O, (ii) NaCl, 2NaCl ⋅ ZnCl 2 ⋅ 2H 2 O, and ZnCl 2 ⋅ 2H 2 O, (iii) NaCl and NaH 2 PO 2 ⋅ H 2 O, (iv) Zn(H 2 PO 2 ) 2 ⋅ H 2 O and NaH 2 PO 2 ⋅ H 2 O, respectively. On the other hand reciprocal quaternary system was observed as: ZnCl 2 ⋅ 2H 2 O, 2NaCl ⋅ ZnCl 2 ⋅ 2H 2 O, Zn(H 2 PO 2 ) 2 ⋅ H 2 O, NaH 2 PO 2 ⋅ H 2 O, NaCl. According to results, the least soluble salt was Zn(H 2 PO 2 ) 2 . The crystallization field of this salt, being the largest in comparison with those of other salts, occupied 70% of the general crystallization field

  1. Tissue polypeptide antigen activity in cerebrospinal fluid

    DEFF Research Database (Denmark)

    Bach, F; Söletormos, Georg; Dombernowsky, P

    1991-01-01

    Tissue polypeptide antigen (TPpA) in the cerebrospinal fluid (CSF) was measured in 59 consecutive breast cancer patients with suspected central nervous system (CNS) metastases. Subsequently, we determined that 13 patients had parenchymal brain metastases, 10 had leptomeningeal carcinomatosis...

  2. Biolubricant Polypeptides and Therapeutic Uses Thereof

    NARCIS (Netherlands)

    Sharma, Prashant; Herrmann, Andreas; Kolbe, Anke; Veeregowda, Deepak; van der Mei, Henderina; Busscher, Hendrik

    2016-01-01

    The invention relates to the field of medicine. In particular, it relates to recombinant cationic polypeptides and their use as biolubricant. Provided is a biolubricant substance comprising the amino acid sequence[(GKGVP)9]n, wherein n is ≧5.

  3. Polypeptides having laccase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ye; Tang, Lan; Duan, Junxin; Zhang, Yu

    2017-08-22

    The present invention relates to isolated polypeptides having laccase activity and polynucleotides encoding the polypeptides and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  4. High purity H2/H2O/Ni/SZ electrodes at 500º C

    DEFF Research Database (Denmark)

    Høgh, Jens Valdemar Thorvald; Hansen, Karin Vels; Norrman, Kion

    2013-01-01

    of stabilized zirconia (SZ) with 10, 13 and 18 mol% yttria and one with 6 mol% scandia plus 4 mol% yttria were studied at open circuit voltage at 400-500 C in mixtures of H2/H2O over 46 days. The polarization resistances (Rp) for all samples increased significantly during the first 10-20 days at 500 C...

  5. Interactions between metal cations with H 2 in the M-H 2 complexes ...

    Indian Academy of Sciences (India)

    Interactions between metal cations with H2 in the M+- H2 complexes: Performance of DFT and DFT-D methods ... Graduate School of Information Science, Nagoya University, Chukusa-ku, Nagoya 464-8601, Aichi, Japan; Department of Spectroscopy, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 ...

  6. I + (H2O)2 → HI + (H2O)OH Forward and Reverse Reactions. CCSD(T) Studies Including Spin-Orbit Coupling.

    Science.gov (United States)

    Wang, Hui; Li, Guoliang; Li, Qian-Shu; Xie, Yaoming; Schaefer, Henry F

    2016-03-03

    The potential energy profile for the atomic iodine plus water dimer reaction I + (H2O)2 → HI + (H2O)OH has been explored using the "Gold Standard" CCSD(T) method with quadruple-ζ correlation-consistent basis sets. The corresponding information for the reverse reaction HI + (H2O)OH → I + (H2O)2 is also derived. Both zero-point vibrational energies (ZPVEs) and spin-orbit (SO) coupling are considered, and these notably alter the classical energetics. On the basis of the CCSD(T)/cc-pVQZ-PP results, including ZPVE and SO coupling, the forward reaction is found to be endothermic by 47.4 kcal/mol, implying a significant exothermicity for the reverse reaction. The entrance complex I···(H2O)2 is bound by 1.8 kcal/mol, and this dissociation energy is significantly affected by SO coupling. The reaction barrier lies 45.1 kcal/mol higher than the reactants. The exit complex HI···(H2O)OH is bound by 3.0 kcal/mol relative to the asymptotic limit. At every level of theory, the reverse reaction HI + (H2O)OH → I + (H2O)2 proceeds without a barrier. Compared with the analogous water monomer reaction I + H2O → HI + OH, the additional water molecule reduces the relative energies of the entrance stationary point, transition state, and exit complex by 3-5 kcal/mol. The I + (H2O)2 reaction is related to the valence isoelectronic bromine and chlorine reactions but is distinctly different from the F + (H2O)2 system.

  7. Electron mass stopping power in H2

    Science.gov (United States)

    Fursa, Dmitry V.; Zammit, Mark C.; Threlfall, Robert L.; Savage, Jeremy S.; Bray, Igor

    2017-08-01

    Calculations of electron mass stopping power (SP) of electrons in H2 have been performed using the convergent close-coupling method for incident electron energies up to 2000 eV. Convergence of the calculated SP has been established by increasing the size of the close-coupling expansion from 9 to 491 states. Good agreement was found with the SP measurements of Munoz et al. [Chem. Phys. Lett. 433, 253 (2007), 10.1016/j.cplett.2006.10.114].

  8. A neural network potential energy surface for the NaH2 system and dynamics studies on the H(2S) + NaH(X1Σ+) → Na(2S) + H2(X1Σg+) reaction.

    Science.gov (United States)

    Wang, Shufen; Yuan, Jiuchuang; Li, Huixing; Chen, Maodu

    2017-08-02

    In order to study the dynamics of the reaction H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ), a new potential energy surface (PES) for the ground state of the NaH 2 system is constructed based on 35 730 ab initio energy points. Using basis sets of quadruple zeta quality, multireference configuration interaction calculations with Davidson correction were carried out to obtain the ab initio energy points. The neural network method is used to fit the PES, and the root mean square error is very small (0.00639 eV). The bond lengths, dissociation energies, zero-point energies and spectroscopic constants of H 2 (X 1 Σ g + ) and NaH(X 1 Σ + ) obtained on the new NaH 2 PES are in good agreement with the experiment data. On the new PES, the reactant coordinate-based time-dependent wave packet method is applied to study the reaction dynamics of H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ), and the reaction probabilities, integral cross-sections (ICSs) and differential cross-sections (DCSs) are obtained. There is no threshold in the reaction due to the absence of an energy barrier on the minimum energy path. When the collision energy increases, the ICSs decrease from a high value at low collision energy. The DCS results show that the angular distribution of the product molecules tends to the forward direction. Compared with the LiH 2 system, the NaH 2 system has a larger mass and the PES has a larger well at the H-NaH configuration, which leads to a higher ICS value in the H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ) reaction. Because the H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ) reaction releases more energy, the product molecules can be excited to a higher vibrational state.

  9. Emission of Lyman α radiation in H2 + H*(2s) collisions at thermal energies

    International Nuclear Information System (INIS)

    Stern, B.

    1991-01-01

    A previously-published study of the thermal-energy collision between H 2 and metastable H*(2s), which could lead to the emission of Lyman α radiation, is reconsidered to take into account possible polarization effects. The total was function of the system is expanded in terms of the molecular states of the intermediate complex H 2 * , which constitute the minimal basis of the four adiabatic states dissociating into H 2 + H*(n=2) where they are normally degenerate in energy. The results of the calculation show the existence, between three of those states, of average values of the separation distance R (R ≅ 10 atomic units) of long range (ΔR ≅ 2 au) electronic interactions which depend on the geometric form of the H 2 * molecule. From the molecular data the hypothesis of no longer considering H 2 with H*(2s) as a rigid rotator is postulated and justified, after a purely quantum mechanical treatment of the radial equations. The mean ratio of the (oscillating) polarization angular differential cross sections tot he elastic ones is found important (> ∼ 1/10). The inelastic phenomena are anticipated to be more marked in the ortho than in the para hydrogen at a low collision energy (75 meV). (15 refs., 2 tabs., 9 figs.)

  10. LC-MS/MS suggests that hole hopping in cytochrome c peroxidase protects its heme from oxidative modification by excess H2O2.

    Science.gov (United States)

    Kathiresan, Meena; English, Ann M

    2017-02-01

    We recently reported that cytochrome c peroxidase (Ccp1) functions as a H 2 O 2 sensor protein when H 2 O 2 levels rise in respiring yeast. The availability of its reducing substrate, ferrocytochrome c (Cyc II ), determines whether Ccp1 acts as a H 2 O 2 sensor or peroxidase. For H 2 O 2 to serve as a signal it must modify its receptor so we employed high-performance LC-MS/MS to investigate in detail the oxidation of Ccp1 by 1, 5 and 10 M eq. of H 2 O 2 in the absence of Cyc II to prevent peroxidase activity. We observe strictly heme-mediated oxidation, implicating sequential cycles of binding and reduction of H 2 O 2 at Ccp1's heme. This results in the incorporation of ∼20 oxygen atoms predominantly at methionine and tryptophan residues. Extensive intramolecular dityrosine crosslinking involving neighboring residues was uncovered by LC-MS/MS sequencing of the crosslinked peptides. The proximal heme ligand, H175, is converted to oxo-histidine, which labilizes the heme but irreversible heme oxidation is avoided by hole hopping to the polypeptide until oxidation of the catalytic distal H52 in Ccp1 treated with 10 M eq. of H 2 O 2 shuts down heterolytic cleavage of H 2 O 2 at the heme. Mapping of the 24 oxidized residues in Ccp1 reveals that hole hopping from the heme is directed to three polypeptide zones rich in redox-active residues. This unprecedented analysis unveils the remarkable capacity of a polypeptide to direct hole hopping away from its active site, consistent with heme labilization being a key outcome of Ccp1-mediated H 2 O 2 signaling. LC-MS/MS identification of the oxidized residues also exposes the bias of electron paramagnetic resonance (EPR) detection toward transient radicals with low O 2 reactivity.

  11. Coulomb repulsion in short polypeptides.

    Science.gov (United States)

    Norouzy, Amir; Assaf, Khaleel I; Zhang, Shuai; Jacob, Maik H; Nau, Werner M

    2015-01-08

    Coulomb repulsion between like-charged side chains is presently viewed as a major force that impacts the biological activity of intrinsically disordered polypeptides (IDPs) by determining their spatial dimensions. We investigated short synthetic models of IDPs, purely composed of ionizable amino acid residues and therefore expected to display an extreme structural and dynamic response to pH variation. Two synergistic, custom-made, time-resolved fluorescence methods were applied in tandem to study the structure and dynamics of the acidic and basic hexapeptides Asp6, Glu6, Arg6, Lys6, and His6 between pH 1 and 12. (i) End-to-end distances were obtained from the short-distance Förster resonance energy transfer (sdFRET) from N-terminal 5-fluoro-l-tryptophan (FTrp) to C-terminal Dbo. (ii) End-to-end collision rates were obtained for the same peptides from the collision-induced fluorescence quenching (CIFQ) of Dbo by FTrp. Unexpectedly, the very high increase of charge density at elevated pH had no dynamical or conformational consequence in the anionic chains, neither in the absence nor in the presence of salt, in conflict with the common view and in partial conflict with accompanying molecular dynamics simulations. In contrast, the cationic peptides responded to ionization but with surprising patterns that mirrored the rich individual characteristics of each side chain type. The contrasting results had to be interpreted, by considering salt screening experiments, N-terminal acetylation, and simulations, in terms of an interplay of local dielectric constant and peptide-length dependent side chain charge-charge repulsion, side chain functional group solvation, N-terminal and side chain charge-charge repulsion, and side chain-side chain as well as side chain-backbone interactions. The common picture that emerged is that Coulomb repulsion between water-solvated side chains is efficiently quenched in short peptides as long as side chains are not in direct contact with each

  12. Carbohydrate degrading polypeptide and uses thereof

    Science.gov (United States)

    Sagt, Cornelis Maria Jacobus; Schooneveld-Bergmans, Margot Elisabeth Francoise; Roubos, Johannes Andries; Los, Alrik Pieter

    2015-10-20

    The invention relates to a polypeptide having carbohydrate material degrading activity which comprises the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1 or SEQ ID NO: 4, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 96% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 96% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional protein and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  13. H2@Scale Resource and Market Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ruth, Mark

    2017-07-12

    This presentation overviews progress to date on the H2@Scale resource and market analysis work. The work finds, for example, that hydrogen demand of 60 MMT/yr is possible when transportation and industry are considered; resources are available to meet that demand; using renewable resources would reduce emissions and fossil use by over 15%; further impacts are possible when considering synergistic benefits; additional analysis is underway to improve understanding of potential markets and synergistic impacts; and further analysis will be necessary to estimate impacts due to spatial characteristics, feedback effects in the economy, and inertia characteristics.

  14. Dissociative phototionization cross sections of H2, SO2 and H2O

    International Nuclear Information System (INIS)

    Chung, Y.

    1989-01-01

    The partial photoionization cross sections of H 2 , SO 2 , and H 2 O were calculated from the measured photoionization branching ratios and the known total photoionization cross sections. The branching ratios were measured with a time-of-flight mass spectrometer and synchrotron radiation. The branching ratios Of H 2 , SO 2 , and H 2 O were measured for 100 ∼ 410, 150 ∼ 380 and 120 ∼ 720 angstrom. The author also measured the photoionization yield Of SO 2 from 520 to 665 angstrom using a double ion chamber and a glow discharge light source. The principle of a time-of-flight mass spectrometer is explained. New calculations were made to see how the design of the mass spectrometer, applied voltage, and kinetic energy of the ions affect the overall performance of the mass spectrometer. Several useful techniques that we used at the synchrotron for wavelength calibration and higher order suppression are also discussed

  15. Primary structure of histone H2A from nucleated erythrocyte of the marine worm Sipunculus nudus. Presence of two forms of H2A in the sipunculid chromatin.

    Science.gov (United States)

    Kmiecik, D; Couppez, M; Belaiche, D; Sautiere, P

    1983-09-01

    The complete amino acid sequence (123 residues) of histone H2A from erythrocytes of the marine worm Sipunculus nudus, has been established from data provided by automated sequence analysis of large fragments generated by V8 staphylococcal protease digestion of histone H2A and by limited hydrolysis of the protein with alpha-chymotrypsin and from structural studies of tryptic peptides of the protein. By comparison with calf homologous histone, the sipunculid histone H2A shows 6 deletions and 13 substitutions. Six of the substitutions are non-conservative. Most of the evolutionary changes are mainly observed in the basic amino-terminal and carboxy-terminal regions of the molecule, which are the primary DNA-binding sites. Few conservative point changes are observed in the central region (residues 18-118) which interacts strongly with histone H2B to form the dimer H2A-H2B. 60% of the H2A molecules were found phosphorylated on the amino-terminal residue, N-acetyl-serine. The high content of phosphorylated histone H2A in the sipunculid erythrocyte chromatin could probably be related to smaller repeat length (177 +/- 5 base pairs) of nucleosomal DNA and to nuclear inactivation and chromatin condensation.

  16. Anharmonic Theoretical Vibrational Spectroscopy of Polypeptides.

    Science.gov (United States)

    Panek, Paweł T; Jacob, Christoph R

    2016-08-18

    Because of the size of polypeptides and proteins, the quantum-chemical prediction of their vibrational spectra presents an exceptionally challenging task. Here, we address one of these challenges, namely, the inclusion of anharmonicities. By performing the expansion of the potential energy surface in localized-mode coordinates instead of the normal-mode coordinates, it becomes possible to calculate anharmonic vibrational spectra of polypeptides efficiently and reliably. We apply this approach to calculate the infrared, Raman, and Raman optical activity spectra of helical alanine polypeptides consisting of up to 20 amino acids. We find that while anharmonicities do not alter the band shapes, simple scaling procedures cannot account for the different shifts found for the individual bands. This closes an important gap in theoretical vibrational spectroscopy by making it possible to quantify the anharmonic contributions and opens the door to a first-principles calculation of multidimensional vibrational spectra.

  17. GLYCOSYLATED YGHJ POLYPEPTIDES FROM ENTEROTOXIGENIC ESCHERICHIA COLI (ETEC)

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to glycosylated YghJ polypeptides from or derived from enterotoxigenic Escherichia coli (ETEC) that are immunogenic. In particular, the present invention relates to compositions or vaccines comprising the polypeptides and their application in immunization, vaccination...

  18. Normaloid Weighted Composition Operators on $H^2$

    OpenAIRE

    Thompson, Derek

    2017-01-01

    When \\ph\\ is an analytic self-map of the unit disk with Denjoy-Wolff point $a \\in \\D$, and $\\rho(\\W) = \\psi(a)$, we give an exact characterization for when \\W\\ is normaloid. We also determine the spectral radius, essential spectral radius, and essential norm for a class of non-compact composition operators whose symbols have Denjoy-Wolff point in \\D. When the Denjoy-Wolff point is on $\\partial \\D$, we give sufficient conditions for several new classes of normaloid weighted composition operators.

  19. Polypeptide electrophoretic pattern of Matricaria chamomilla and ...

    African Journals Online (AJOL)

    In order to study the effects of salinity and Fe-deficiency on electrophoresis pattern of polypeptides in two chamomile genera (Matricaria chamomilla and Anthemis nobilis), a factorial experiment was conducted based on completely randomized block design with three replications, in 2010. The experimental factors were two ...

  20. Recombinant Supercharged Polypeptides Restore and Improve Biolubrication

    NARCIS (Netherlands)

    Veeregowda, Deepak H.; Kolbe, Anke; van der Mei, Henny C.; Busscher, Henk J.; Herrmann, Andreas; Sharma, Prashant K.

    2013-01-01

    Recombinant supercharged polypeptides (SUPs) with low cytotoxicity are developed and applied to rejuvenate the lubrication of naturally occurring salivary conditioning films (SCFs). SUPs with 72 positive charges adsorbed and rigidified the SCFs and recruited mucins to form a hydrated layer. These

  1. Tuning Ice Nucleation with Supercharged Polypeptides

    NARCIS (Netherlands)

    Yang, Huige; Ma, Chao; Li, Kaiyong; Liu, Kai; Loznik, Mark; Teeuwen, Rosalie; van Hest, Jan C. M.; Zhou, Xin; Herrmann, Andreas; Wang, Jianjun

    2016-01-01

    Supercharged unfolded polypeptides (SUPs) are exploited for controlling ice nucleation via tuning the nature of charge and charge density of SUPs. The results show that positively charged SUPs facilitate ice nucleation, while negatively charged ones suppress it. Moreover, the charge density of the

  2. Endogenous pancreatic polypeptide in different vascular beds

    DEFF Research Database (Denmark)

    Henriksen, J H; Schwartz, Tania; Bülow, J B

    1986-01-01

    The plasma concentration of pancreatic polypeptide (PP-like immunoreactivity) was measured in different vascular beds in order to determine regional kinetics of endogenous PP in fasting, supine subjects with normal or moderately decreased kidney function. Patients with kidney disease (n = 10) had...

  3. Molecular beam scattering experiments with polar molecules. 1. Differential elastic scattering of H2+NH3 and H2+H2O

    International Nuclear Information System (INIS)

    Bickes, R.W. Jr.; Scoles, G.; Smith, K.M.

    1974-01-01

    Differential elastic scattering cross sections with well resolved quantum oscillations have been measuremed for the systems H 2 +NH 3 and H 2 +H 2 O. Assuming a spherically symmetric interaction the data show that a simple spherical potential (i.e. Lennard-Jones) does not properly describe the scattering

  4. Polypeptides having xylanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj; Shaghasi, Tarana

    2017-06-20

    The present invention relates to polypeptides having xylanase activity, catalytic domains, and carbohydrate binding domains, and polynucleotides encoding the polypeptides, catalytic domains, and carbohydrate binding domains. The present invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides, catalytic domains, and carbohydrate binding domains.

  5. Polypeptides having endoglucanase activity and polynucleotides encoding same

    Science.gov (United States)

    Spodsberg, Nikolaj

    2016-02-23

    The present invention relates to isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  6. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Science.gov (United States)

    Schnorr, Kirk; Kramer, Randall

    2016-04-05

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  7. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    Science.gov (United States)

    Harris, Paul; Golightly, Elizabeth

    2007-07-17

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  8. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Schnorr, Kirk; Kramer, Randall

    2017-08-08

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  9. Polypeptides having beta-xylosidase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Liu, Ye; Duan, Junxin; Tang, Lan; McBrayer, Brett

    2017-07-04

    The present invention relates to isolated polypeptides having beta-xylosidase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  10. Polypeptides having xylanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Lopez de Leon, Alfredo; Rey, Michael

    2017-09-26

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  11. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ye; Tang, Lan; Duan, Junxin

    2017-02-07

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  12. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding the same

    Science.gov (United States)

    Duan, Junxin; Schnorr, Kirk Matthew; Wu, Wenping

    2013-11-19

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  13. Chimeric polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Science.gov (United States)

    Wogulis, Mark; Sweeney, Matthew; Heu, Tia

    2017-06-14

    The present invention relates to chimeric GH61 polypeptides having cellulolytic enhancing activity. The present invention also relates to polynucleotides encoding the chimeric GH61 polypeptides; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the chimeric GH61 polypeptides.

  14. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Stringer, Mary Ann; McBrayer, Brett

    2016-11-29

    The present invention relates to isolated polypeptides having cellobiohydrolase activity, catalytic domains, and cellulose binding domains and polynucleotides encoding the polypeptides, catalytic domains, and cellulose binding domains. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides, catalytic domains, or cellulose binding domains.

  15. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Lan; Liu, Ye; Duan, Junxin; Zhang, Yu; Joergensen, Christian; Kramer, Randall

    2016-11-29

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  16. Polypeptides having xylanase activity and polynucleotides encoding same

    Science.gov (United States)

    Tang, Lan; Liu, Ye; Duan, Junxin; Hanshu, Ding

    2012-10-30

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  17. Polynucleotides encoding polypeptides having beta-glucosidase activity

    Science.gov (United States)

    Harris, Paul; Golightly, Elizabeth

    2010-03-02

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  18. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Science.gov (United States)

    Maiyuran, Suchindra; Kramer, Randall; Harris, Paul

    2013-10-29

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  19. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Duan, Junxin; Tang, Lan; Wu, Wenping

    2016-11-22

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  20. Polypeptides having cellulolytic enhancing activity and nucleic acids encoding same

    Science.gov (United States)

    Brown, Kimberly; Harris, Paul; Zaretsky, Elizabeth; Re, Edward; Vlasenko, Elena; McFarland, Keith; Lopez de Leon, Alfredo

    2012-10-16

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  1. Polypeptides having xylanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Lopez de Leon, Alfredo; Rey, Michael

    2016-05-31

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  2. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Duan, Junxin; Tang, Lan; Wu, Wenping

    2016-06-14

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  3. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Lan; Liu, Ye; Duan, Junxin; Wu, Wenping; Kramer, Randall

    2017-09-19

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  4. Polypeptides having endoglucanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj; Shagasi, Tarana

    2017-05-30

    The present invention relates to isolated polypeptides having endoglucanase activity, catalytic domains, cellulose binding domains and polynucleotides encoding the polypeptides, catalytic domains or cellulose binding domains. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides, catalytic domains or cellulose binding domains.

  5. Polypeptides having endoglucanase activity and polynucleotides encoding same

    Science.gov (United States)

    Harris, Paul; Lopez de Leon, Alfredo; Rey, Michael; Ding, Hanshu; Vlasenko, Elena

    2010-11-02

    The present invention relates to isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  6. Polypeptides having cellulolytic enhancing activity and nucleic acids encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Kimberly; Harris, Paul; Zaretsky, Elizabeth; Re, Edward; Vlasenko, Elena; McFarland, Keith; Lopez de Leon, Alfredo

    2016-08-09

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  7. Polypeptides having cellulolytic enhancing activity and nucleic acids encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Kimberly; Harris, Paul; Zaretsky, Elizabeth; Re, Edward; Vlasenko, Elena; McFarland, Keith; Lopez de Leon, Alfredo

    2017-09-05

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  8. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Schnorr, Kirk; Kramer, Randall

    2016-08-09

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  9. Polypeptides having xylanase activity and polynucleotides encoding the same

    Science.gov (United States)

    Spodsberg, Nikolaj [Bagsvaed, DK

    2014-01-07

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The inventino also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  10. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    Science.gov (United States)

    Morant, Marc Dominique

    2014-10-14

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  11. Polypeptide from a cellulolytic fungus having cellulolytic enhancing activity

    Science.gov (United States)

    Brown, Kimberly [Elk Grove, CA; Harris, Paul [Carnation, WA; Zaretsky, Elizabeth [Reno, NV; Re, Edward [Davis, CA; Vlasenko, Elena [Davis, CA; McFarland, Keith [Davis, CA; Lopez de Leon, Alfredo [Davis, CA

    2008-04-22

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  12. Polypeptides having endoglucanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Liu, Ye; Duan, Junxin; Tang, Lan

    2018-01-30

    The present invention relates to isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  13. H2O2 space shuttle APU

    Science.gov (United States)

    1975-01-01

    A cryogenic H2-O2 auxiliary power unit (APU) was developed and successfully demonstrated. It has potential application as a minimum weight alternate to the space shuttle baseline APU because of its (1) low specific propellant consumption and (2) heat sink capabilities that reduce the amount of expendable evaporants. A reference system was designed with the necessary heat exchangers, combustor, turbine-gearbox, valves, and electronic controls to provide 400 shp to two aircraft hydraulic pumps. Development testing was carried out first on the combustor and control valves. This was followed by development of the control subsystem including the controller, the hydrogen and oxygen control valves, the combustor, and a turbine simulator. The complete APU system was hot tested for 10 hr with ambient and cryogenic propellants. Demonstrated at 95 percent of design power was 2.25 lb/hp-hr. At 10 percent design power, specific propellant consumption was 4 lb/hp-hr with space simulated exhaust and 5.2 lb/hp-hr with ambient exhaust. A 10 percent specific propellant consumption improvement is possible with some seal modifications. It was demonstrated that APU power levels could be changed by several hundred horsepower in less than 100 msec without exceeding allowable turbine inlet temperatures or turbine speed.

  14. Methodological aspects of breath hydrogen (H2) analysis. Evaluation of a H2 monitor and interpretation of the breath H2 test

    DEFF Research Database (Denmark)

    Rumessen, J J; Kokholm, G; Gudmand-Høyer, E

    1987-01-01

    The reliability of end-expiratory hydrogen (H2) breath tests were assessed and the significance of some important pitfalls were studied, using a compact, rapid H2-monitor with electrochemical cells. The H2 response was shown to be linear and stable. The reproducibility of the breath collection...... technique was determined in 20 patients following ingestion of lactulose. The increment between consecutive means of duplicate samples indicative of a significant rise of H2 concentration never exceeded 10 p.p.m., the mean coefficient of variation of the duplicate samples was below 5%. Fasting H2 levels...

  15. The synthesis of [2-3H2] taurine and [2-3H2] hypotaurine

    International Nuclear Information System (INIS)

    Fellman, J.H.

    1981-01-01

    The synthesis of [2- 3 H 2 ]-2-aminoethanesulfonate [2- 3 H]-taurine by the reduction of cyanomethanesulfonic acid with tritium gas is described. The conversion of [2- 3 H]-taurine and its 14 C and 35 S isotopic forms to 2-aminoethanesulfinate (hypotaurine) was accomplished by converting taurine to its corresponding sulfonyl chloride and reducing the latter with metallic zinc. (author)

  16. Energy Transfer to the Hydrogen Bond in the (H2O)2+ H2O Collision.

    Science.gov (United States)

    Shin, H K

    2017-12-08

    Trajectory procedures are used to study the collision between the vibrationally excited H 2 O and the ground-state (H 2 O) 2 with particular reference to energy transfer to the hydrogen bond through the inter- and intramolecular pathways. In nearly 98% of the trajectories, energy transfer processes occur on a subpicosecond scale (≤0.7 ps). The H 2 O transfers approximately three-quarters of its excitation energy to the OH stretches of the dimer. The first step of the intramolecular pathway in the dimer involves a near-resonant first overtone transition from the OH stretch to the bending mode. The energy transfer probability in the presence of the 1:2 resonance is 0.61 at 300 K. The bending mode then redistributes its energy to low-frequency intermolecular vibrations in a series of small excitation steps, with the pathway which results in the hydrogen-bonding modes gaining most of the available energy. The hydrogen bonding in ∼50% of the trajectories ruptures on vibrational excitation, leaving one quantum in the bend of the monomer fragment. In a small fraction of trajectories, the duration of collision is longer than 1 ps, during which the dimer and H 2 O form a short-lived complex through a secondary hydrogen bond, which undergoes large amplitude oscillations.

  17. Histone H2B monoubiquitination facilitates the rapid modulation of gene expression during Arabidopsis photomorphogenesis.

    Directory of Open Access Journals (Sweden)

    Clara Bourbousse

    Full Text Available Profiling of DNA and histone modifications has recently allowed the establishment of reference epigenomes from several model organisms. This identified a major chromatin state for active genes that contains monoubiquitinated H2B (H2Bub, a mark linked to transcription elongation. However, assessment of dynamic chromatin changes during the reprogramming of gene expression in response to extrinsic or developmental signals has been more difficult. Here we used the major developmental switch that Arabidopsis thaliana plants undergo upon their initial perception of light, known as photomorphogenesis, as a paradigm to assess spatial and temporal dynamics of monoubiquitinated H2B (H2Bub and its impact on transcriptional responses. The process involves rapid and extensive transcriptional reprogramming and represents a developmental window well suited to studying cell division-independent chromatin changes. Genome-wide H2Bub distribution was determined together with transcriptome profiles at three time points during early photomorphogenesis. This revealed de novo marking of 177 genes upon the first hour of illumination, illustrating the dynamic nature of H2Bub enrichment in a genomic context. Gene upregulation was associated with H2Bub enrichment, while H2Bub levels generally remained stable during gene downregulation. We further report that H2Bub influences the modulation of gene expression, as both gene up- and downregulation were globally weaker in hub1 mutant plants that lack H2Bub. H2Bub-dependent regulation notably impacted genes with fast and transient light induction, and several circadian clock components whose mRNA levels are tightly regulated by sharp oscillations. Based on these findings, we propose that H2B monoubiquitination is part of a transcription-coupled, chromatin-based mechanism to rapidly modulate gene expression.

  18. Generation of H_2 and CO by solar thermochemical splitting of H_2O and CO_2 by employing metal oxides

    International Nuclear Information System (INIS)

    Rao, C.N.R.; Dey, Sunita

    2016-01-01

    Generation of H_2 and CO by splitting H_2O and CO_2 respectively constitutes an important aspect of the present-day concerns with energy and environment. The solar thermochemical route making use of metal oxides is a viable means of accomplishing these reduction reactions. The method essentially involves reducing a metal oxide by heating and passing H_2O or CO_2 over the nonstoichiometric oxide to cause reverse oxidation by abstracting oxygen from H_2O or CO_2. While ceria, perovskites and other oxides have been investigated for this purpose, recent studies have demonstrated the superior performance of perovskites of the type Ln_1_−_xA_xMn_1_−_yM_yO_3 (Ln=rare earth, A=alkaline earth, M=various +2 and +3 metal ions), in the thermochemical generation of H_2 and CO. We present the important results obtained hitherto to point out how the alkaine earth and the Ln ions, specially the radius of the latter, determine the performance of the perovskites. The encouraging results obtained are exemplefied by Y_0_._5Sr_0_._5MnO_3 which releases 483 µmol/g of O_2 at 1673 K and produces 757 µmol/g of CO from CO_2 at 1173 K. The production of H_2 from H_2O is also quite appreciable. Modification of the B site ion of the perovskite also affects the performance. In addition to perovskites, we present the generation of H_2 based on the Mn_3O_4/NaMnO_2 cycle briefly. - Graphical abstract: Ln_0_._5A_0_._5Mn_1_−_xM_xO_3 (Ln=lanthanide; A=Ca, Sr; M=Al, Ga, Sc, Mg, Cr, Fe, Co) perovskites are employed for the two step thermochemical splitting of CO_2 and H_2O for the generation of CO and H_2. - Highlights: • Perovskite oxides based on Mn are ideal for the two-step thermochemical splitting of CO_2 and H_2O. • In Ln_1_−_xA_xMnO_3 perovskite (Ln=rare earth, A=alkaline earth) both Ln and A ions play major roles in the thermochemical process. • H_2O splitting is also achieved by the use of the Mn_3O_4-sodium carbonate system. • Thermochemical splitting of CO_2 and H_2O using

  19. Measles virus polypeptides in purified virions and in infected cells

    International Nuclear Information System (INIS)

    Vainionpaeae, R.; Ziola, B.; Salmi, A.

    1978-01-01

    A wild-type measles virus was radiolabeled during growth in VERO cells and purified by two successive potassium tartrate gradient centrifugations. The virion polypeptide composition was determined by SDS-polyacrylamide gel electrophoresis employing two different buffer systems. Six virus-specific polypeptides were consistently detected. The largest (L) had a molecular weight (MW) of greater than 150,000. The second largest polypeptide, G (MW 79,000), was the only glycoprotein found. The proteins designated polypeptide 2 (MW 66 to 70,000) and nucleocapsid protein or NP (MW 61,000) were phosphorylated. The remaining virus-coded proteins were polypeptide 5 (MW 40,000) and the matrix or M protein (MW 37,000). Measles virions also contained a polypeptide (MW 42,000) thought to be actin due to co-migration with this component of uninfected cells. Analysis of in vitro 3 H-acetic anhydride radiolabeled virions confirmed the presence of these seven polypeptides. Acetic anhydride also labeled a protein designated polypeptide 4 (MW 53,000) which was not consistently radiolabeled in vivo, as well as several other minor proteins believed to be cellular in origin. Synthesis of the six virus-specific structural polypeptides was detected in lysates of infected cells by SDS-polyacrylamide slab gel electrophoresis. Virus specificity of polypeptide 4 could not be confirmed due to the similar MW of several cellular polypeptides. Two non-virion, but virus-specified polypeptides, of MW 38,000 and 18,000 were also detected. Synthesis of the virus structural proteins was in the same proportions as the polypeptides found in virions except for under production of polypeptide G and over production of polypeptide 2. (author)

  20. Preparation of rat gastric heavy and light microsomal membranes enriched in (H+-K+)-ATPase using 2H2O and Percoll gradients

    International Nuclear Information System (INIS)

    Im, W.B.; Davis, J.P.; Blakeman, D.P.

    1985-01-01

    Gastric heavy microsomal membranes highly enriched in (H + -K + )-ATPase were obtained from cimetidine- or carbachol-treated rats through 2 H 2 O and Percoll gradient centrifugations. Both the resting (cimetidine-treated) and the stimulated (carbachol-treated) heavy membranes which presumably represent the apical membrane of gastric parietal cells were enriched with the polypeptides of 81,000 and 45,000 besides that of 93,000 representing (H + -K + )-ATPase. No apparent differences could be detected between the resting and the stimulated heavy membranes in their polypeptide profiles or their specific activity of (H + -K + )-ATPase. Nevertheless, the level of 86 RbCl uptake was greater in the stimulated than the resting heavy microsomal membrane vesicles. The light gastric microsomes which abound in intracellular tubulovesicles containing reserve (H + -K + )-ATPase as isolated from cimetidine-treated rats were similarly purified with respect to (H + -K + )-ATPase. The purified light gastric membranes were largely devoid of the polypeptides of 81,000 and 45,000 found in the heavy gastric membranes. These observations further support the current hypothesis that secretagogues bring about changes in the environment of (H + -K + )-ATPase and induce KCl permeability in the apical membrane of the parietal cells, although at present the authors have been unable to identify the polypeptide(s) responsible for the KCl pathway

  1. State resolved rotational excitation cross-sections and rates in H2 + H2 collisions

    International Nuclear Information System (INIS)

    Sultanov, Renat A.; Guster, Dennis

    2006-01-01

    Rotational transitions in molecular hydrogen collisions are computed. The two most recently developed potential energy surfaces for the H 2 -H 2 system are used from the following works: [A.I. Boothroyd, P.G. Martin, W.J. Keogh, M.J. Peterson, J. Chem. Phys., 116 (2002) 666; P. Diep, J.K. Johnson, J. Chem. Phys., 113 (2000) 3480; P. Diep, J.K. Johnson, J. Chem. Phys., 112 (2000) 4465]. Cross-sections for rotational transitions 00 → 20, 22, 40, 42, 44 and corresponding rate coefficients are calculated using a quantum-mechanical approach. Results are compared for a wide range of kinetic temperatures 300 K ≤ T≤ 3000 K

  2. Behaviour of ceramic and metallic layers in a H2O-H2S

    International Nuclear Information System (INIS)

    Furtuna, I.; Mihailescu, M.; Deaconu, M.; Dinu, A.; Cotolan, V; Nedelcu, L.; Titescu, Gh.

    1996-01-01

    In the installations for heavy water production there exist zones where the action of aggressive working conditions combined with a severe variable hydrodynamical regime lead to the destruction of the pyrite protecting layer. An alternating solution for the protection of these zones is to cover them with ceramic or metallic layers. This work presents the results of the preliminary tests on G28-52 steel samples, covered with ceramic and metallic layers, in the working environment (H 2 O-H 2 S) of the heavy water production installations and in severe hydrodynamical conditions. On the basis of the results obtained in the experiments and from the examination of the microstructure of the layers prior and after testing, a phenomenological model was developed to explain the behaviour of the deposed layers. On the basis of this model the conditions that the layers must satisfy have been deduced to improve their behaviour in the working environment

  3. A new potential surface and quasiclassical trajectory study of H+H2O→OH+H2

    International Nuclear Information System (INIS)

    Wu, Guo-sheng; Schatz, George C.; Lendvay, G.; Fang, De-Cai; Harding, L. B.

    2000-01-01

    We present a method for developing potential-energy surfaces for abstraction reactions with four or more atoms which combines spline fits to high quality ab initio results for the three degrees of freedom that are most active in the reaction (two stretches and a bend) with simple empirical functions (Morse stretches, cosine bends, and torsions) for the spectator variables. The geometry and force constants associated with the spectator modes are allowed to vary along the reaction path so as to match stationary point properties from the ab initio calculations. In an application of this approach to the H+H 2 O reaction, we are able to generate a global surface for the H 3 O system that accurately matches ab initio properties, and is globally smooth and free of artifacts. Quasiclassical trajectory (QCT) calculations are used with this surface to study the H+H 2 O reaction dynamics for both the ground and local mode excited states. The resulting ground-state angular distributions, product state vibrational and rotational distributions, and rotational alignment factors are in excellent agreement with all known experiments. This represents an improvement over the results obtained using previous surfaces, but like the past surfaces, the calculated integral cross sections are below experiment by at least a factor of 2. For studies of the H+H 2 O reaction involving local mode excited states of water, the new surface is consistent with ab initio threshold behavior, with the (04) - local mode state having zero activation energy. However the reactive rate coefficients are substantially smaller than the observed total reactive plus inelastic rate coefficient. This indicates that recent experiments due to Barnes, Sharkey, Sims, and Smith are dominated by energy transfer rather than reaction. (c) 2000 American Institute of Physics

  4. The Orion Fingers: H2 Temperatures and Excitation in an Explosive Outflow

    Science.gov (United States)

    Youngblood, Allison; France, Kevin; Ginsburg, Adam; Hoadley, Keri; Bally, John

    2018-04-01

    We measure H2 temperatures and column densities across the Orion Becklin-Neugebauer/Kleinmann-Low (BN/KL) explosive outflow from a set of 13 near-infrared (IR) H2 rovibrational emission lines observed with the TripleSpec spectrograph on Apache Point Observatory’s 3.5 m telescope. We find that most of the region is well characterized by a single temperature (∼2000–2500 K), which may be influenced by the limited range of upper-energy levels (6000–20,000 K) probed by our data set. The H2 column density maps indicate that warm H2 comprises 10‑5–10‑3 of the total H2 column density near the center of the outflow. Combining column density measurements for co-spatial H2 and CO at T = 2500 K, we measure a CO/H2 fractional abundance of 2 × 10‑3 and discuss possible reasons why this value is in excess of the canonical 10‑4 value, including dust attenuation, incorrect assumptions on co-spatiality of the H2 and CO emission, and chemical processing in an extreme environment. We model the radiative transfer of H2 in this region with ultraviolet (UV) pumping models to look for signatures of H2 fluorescence from H I Lyα pumping. Dissociative (J-type) shocks and nebular emission from the foreground Orion H II region are considered as possible Lyα sources. From our radiative transfer models, we predict that signatures of Lyα pumping should be detectable in near-IR line ratios given a sufficiently strong source, but such a source is not present in the BN/KL outflow. The data are consistent with shocks as the H2 heating source.

  5. POLYPEPTIDE AND POLYSACCHARIDE PROCESSING IN HYPERTHERMOPHILIC MICROORGANISMS

    Energy Technology Data Exchange (ETDEWEB)

    KELLY, ROBERT M.

    2008-12-22

    This project focused on the microbial physiology and biochemistry of heterotrophic hyperthermophiles with respect to mechanisms by which these organisms process polypeptides and polysaccharides under normal and stressed conditions. Emphasis is on two model organisms, for which completed genome sequences are available: Pyrococcus furiosus (growth Topt of 98°C), an archaeon, and Thermotoga maritima (growth Topt of 80°C), a bacterium. Both organisms are obligately anaerobic heterotrophs that reduce sulfur facultatively. Whole genome cDNA spotted microarrays were used to follow transcriptional response to a variety of environmental conditions in order to identify genes encoding proteins involved in the acquisition, synthesis, processing and utilization of polypeptides and polysaccharides. This project provided new insights into the physiological aspects of hyperthermophiles as these relate to microbial biochemistry and biological function in high temperature habitats. The capacity of these microorganisms to produce biohydrogen from renewable feedstocks makes them important for future efforts to develop biofuels.

  6. Catalytic activity of Ni-Cr2O3 in the H2-NH3 and H2-H2O deuterium exchange reactions

    International Nuclear Information System (INIS)

    Palibroda, N.; Grecu, E.; Marginean, P.

    1986-01-01

    The activity of Ni-Cr 2 O 3 catalyst for the deuterium exchange reactions between hydrogen and ammonia, as well as for hydrogen and water vapor has been measured as a function of the reaction temperature and the partial pressure of ammonia and water vapor, respectively. In both cases the activity shows a maximum depending on the partial pressure; the maximum of activity for H 2 -NH 3 exchange is situated between partial pressures of 0.05 and 0.25, and for H 2 -H 2 O reaction between 0.25 and 0.5. The Ni-Cr 2 O 3 catalyst is about 2.4 more active for the exchange reaction H 2 -H 2 O than for H 2 -NH 3 . For both reactions, chromium(III) oxide has a strong promoting effect, enhancing the activity per gram of catalyst of about three orders of magnitude in comparison with that of nickel. (author)

  7. Hydrogen constituents of the mesosphere inferred from positive ions - H2O, CH4, H2CO, H2O2, and HCN

    Science.gov (United States)

    Kopp, E.

    1990-01-01

    The concentrations in the mesosphere of H2O, CH4, H2CO, H2O2, and HCN were inferred from data on positive ion compositions, obtained from one mid-latitude and four high-latitude rocket flights. The inferred concentrations were found to agree only partially with the ground-based microwave measurements and/or model prediction by Garcia and Solomon (1985). The CH4 concentration was found to vary between 70 and 4 ppb in daytime and 900 and 100 ppbv at night, respectively. Unexpectedly high H2CO concentrations were obtained, with H2CO/H2O ratios between 0.0006 and 0.1, and a mean HCN volume mixing ratio of 6 x 10 to the -10th was inferred.

  8. Nanostructured complexes of polyelectrolytes and charged polypeptides

    Czech Academy of Sciences Publication Activity Database

    Müller, M.; Ouyang, W.; Bohatá, Karolína; Kessler, B.

    2010-01-01

    Roč. 12, Sp. Iss. 9 (2010), B519-B528 ISSN 1438-1656. [Sino-German Symposium on Advanced Biomedical Nanostructures /1./. Jena, 26.10.2009-30.10.2009] Institutional research plan: CEZ:AV0Z40500505 Keywords : situ ATR-FTIR * alpha-helical polypeptides * multilayer films Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.746, year: 2010

  9. Improved docking of polypeptides with Glide.

    Science.gov (United States)

    Tubert-Brohman, Ivan; Sherman, Woody; Repasky, Matt; Beuming, Thijs

    2013-07-22

    Predicting the binding mode of flexible polypeptides to proteins is an important task that falls outside the domain of applicability of most small molecule and protein-protein docking tools. Here, we test the small molecule flexible ligand docking program Glide on a set of 19 non-α-helical peptides and systematically improve pose prediction accuracy by enhancing Glide sampling for flexible polypeptides. In addition, scoring of the poses was improved by post-processing with physics-based implicit solvent MM-GBSA calculations. Using the best RMSD among the top 10 scoring poses as a metric, the success rate (RMSD ≤ 2.0 Å for the interface backbone atoms) increased from 21% with default Glide SP settings to 58% with the enhanced peptide sampling and scoring protocol in the case of redocking to the native protein structure. This approaches the accuracy of the recently developed Rosetta FlexPepDock method (63% success for these 19 peptides) while being over 100 times faster. Cross-docking was performed for a subset of cases where an unbound receptor structure was available, and in that case, 40% of peptides were docked successfully. We analyze the results and find that the optimized polypeptide protocol is most accurate for extended peptides of limited size and number of formal charges, defining a domain of applicability for this approach.

  10. Acetate enhances startup of a H2-producing microbial biocathode

    NARCIS (Netherlands)

    Jeremiasse, A.W.; Hamelers, H.V.M.; Croese, E.; Buisman, C.J.N.

    2012-01-01

    H2 can be produced from organic matter with a microbial electrolysis cell (MEC). To decrease MEC capital costs, a cathode is needed that is made of low-cost material and produces H2 at high rate. A microbial biocathode is a low-cost candidate, but suffers from a long startup and a low H2 production

  11. EERE-SBIR technology transfer opportunity. H2 Safety Sensors for H2

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Mariann R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-12-01

    The Office of Energy Efficiency and Renewable Energy’s Fuel Cell Technologies Office (FCTO) works in partnership with industry (including small businesses), academia, and DOE's national laboratories to establish fuel cell and hydrogen energy technologies as economically competitive contributors to U.S. transportation needs. The work that is envisioned between the SBIR/STTR grantee and Los Alamos National Laboratory would involve Technical Transfer of Los Alamos Intellectual Property (IP) on Thin-film Mixed Potential Sensor (U.S. Patent 7,264,700) and associated know-how for H2 sensor manufacturing and packaging.

  12. H2T liquid hydrogen delivery system

    International Nuclear Information System (INIS)

    Roy, S.

    2002-01-01

    This Power Point presentation provides a preliminary evaluation of the cost of delivering liquid hydrogen produced in Quebec to hydrogen fuelled cars in Germany. The presentation describes the chain of events regarding liquid hydrogen delivery, beginning with the production of hydrogen from an initial source of hydro power. Water passes through an electrolyzer where hydrogen is liquefied and then placed into a container which is transported to market via truck, rail or tanker. Once transported, the hydrogen fuel is made available for consumers at refueling stations. The paper lists the costs related to transportation with reference to safety rules, pure transportation costs, leasing fees for the containers, and permission of customs duties for the import of hydrogen and export of empty containers between Quebec and Germany. A graph depicting a typical refueling station in Germany and the refueling events per hour was presented. For safety reasons, refueling is performed by a refueling robot. A blueprint of safety and protection distances at a refueling station was also presented. tabs., figs

  13. Observations of the H2S toward OMC-1

    Science.gov (United States)

    Minh, Y. C.; Irvine, W. M.; Mcgonagle, D.; Ziurys, L. M.

    1990-01-01

    Observations of the 1(10) - 1(01) transition of interstellar H2S and its isotopes toward OMC-1 are reported. The fractional abundance of H2S in the quiescent regions of OMC-1 seems difficult to explain by currently known ion-molecular reactions. The fractional abundance of H2S relative to H2 is enhanced by a factor of 1000 in the hot core and the plateau relative to the quiescent clouds. The (HDS)/(H2S) abundance ratio in the hot core is estimated at 0.02 or less.

  14. Dynamic investigation of the diffusion absorption refrigeration system NH3-H2O-H2

    Directory of Open Access Journals (Sweden)

    Mohamed Izzedine Serge Adjibade

    2017-09-01

    Full Text Available This paper reports on a numerical and experimental study of a diffusion absorption refrigerator. The performance of the system is examined by computer simulation using MATLAB software and Engineering Equations Solver. A dynamic model is developed for each component of the system and solved numerically in order to predict the transient state of the diffusion absorption refrigeration. The experiment set included 0.04 m3 commercial absorption diffusion refrigerator working with the ammonia-water-hydrogen (NH3-H2O-H2 solution. The transient numerical results were validated with the experimental data. The investigations are focused on the dynamic profile of the temperature of each component. The results obtained agree with the experiment; the relative error between numerical and experimental models doesn’t exceed 15% for all temperatures of each component. The increase of the average ambient temperature from 23.04 °C to 32.56 °C causes an increase of the condensation temperature from 29.46 °C to 37.51 °C, and the best evaporation temperature obtained was 3 °C, with an ambient temperature of 23.04 °C. The results show that a minimum starting temperature of 152 °C and 63.8 W electric power are required to initiate the decrease of evaporation temperature.

  15. Polypeptide having carbohydrate degrading activity and uses thereof

    Science.gov (United States)

    Schooneveld-Bergmans, Margot Elisabeth Francoise; Heijne, Wilbert Herman Marie; Vlasie, Monica Diana; Damveld, Robbertus Antonius

    2015-08-18

    The invention relates to a polypeptide comprising the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 73% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 73% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional polypeptide and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  16. Polypeptide having acetyl xylan esterase activity and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Schoonneveld-Bergmans, Margot Elisabeth Francoise; Heijne, Wilbert Herman Marie; Los, Alrik Pieter

    2015-10-20

    The invention relates to a polypeptide comprising the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 82% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 82% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional polypeptide and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  17. Anion and pH-dependent conformational transition of an amphiphilic polypeptide.

    Science.gov (United States)

    Goto, Y; Aimoto, S

    1991-03-20

    While several proteins, including beta-lactamase, cytochrome c and apomyoglobin, are maximally unfolded at pH 2 by HCl in the absence of salt, the addition of anions, either from salt or acid, co-operatively induces the unfolded proteins to refold to a molten globule state, because anions bind preferentially to the compact molten globule state compared to the extended unfolded state. To study the role of the anion-dependent conformational transition at neutral pH, we synthesized a model polypeptide of 51 amino acid residues, consisting of tandem repeats of a Lys-Lys-Leu-Leu sequence and containing a turn sequence, Asn-Pro-Gly, at the center of the molecule. The model polypeptide showed no significant conformation by circular dichroism under conditions of low salt at neutral pH. However, addition of anions, either from salt or acid, induced the folding transition to an alpha-helical conformational state. The order of effectiveness of various anions in inducing the folding transition was consistent with the series of anions in inducing the molten globule of the acid-denatured protein. This suggests that the helical state of the model polypeptide is equivalent to the molten globule state. At pH values above 9, the model polypeptide also took an alpha-helical conformation, which was very similar to that induced by anions. On the basis of the chloride and pH-dependent conformational transitions, a phase diagram for the conformational states was constructed. The phase diagram was explained simply by assuming that the conformational transition is linked to the proton and the anion bindings to a limited number of amino groups and that anions bind only to the protonated groups.

  18. Ordered Nanostructures Made Using Chaperonin Polypeptides

    Science.gov (United States)

    Trent, Jonathan; McMillan, Robert; Paavola, Chad; Mogul, Rakesh; Kagawa, Hiromi

    2004-01-01

    A recently invented method of fabricating periodic or otherwise ordered nanostructures involves the use of chaperonin polypeptides. The method is intended to serve as a potentially superior and less expensive alternative to conventional lithographic methods for use in the patterning steps of the fabrication of diverse objects characterized by features of the order of nanometers. Typical examples of such objects include arrays of quantum dots that would serve as the functional building blocks of future advanced electronic and photonic devices. A chaperonin is a double-ring protein structure having a molecular weight of about 60 plus or minus 5 kilodaltons. In nature, chaperonins are ubiquitous, essential, subcellular structures. Each natural chaperonin molecule comprises 14, 16, or 18 protein subunits, arranged as two stacked rings approximately 16 to 18 nm tall by approximately 15 to 17 nm wide, the exact dimensions depending on the biological species in which it originates. The natural role of chaperonins is unknown, but they are believed to aid in the correct folding of other proteins, by enclosing unfolded proteins and preventing nonspecific aggregation during assembly. What makes chaperonins useful for the purpose of the present method is that under the proper conditions, chaperonin rings assemble themselves into higher-order structures. This method exploits such higher-order structures to define nanoscale devices. The higher-order structures are tailored partly by choice of chemical and physical conditions for assembly and partly by using chaperonins that have been mutated. The mutations are made by established biochemical techniques. The assembly of chaperonin polypeptides into such structures as rings, tubes, filaments, and sheets (two-dimensional crystals) can be regulated chemically. Rings, tubes, and filaments of some chaperonin polypeptides can, for example, function as nano vessels if they are able to absorb, retain, protect, and release gases or

  19. XPS study on the surface reaction of uranium metal in H2 and H2-CO atmospheres

    International Nuclear Information System (INIS)

    Wang Xiaolin; Fu Yibei; Xie Renshou

    1996-04-01

    The surface reactions of uranium metal in H 2 and H 2 -CO atmospheres and the effects of temperature and CO on the hydriding reaction have been studied by X-ray photoelectron spectroscopy (XPS). The reaction between commercial H 2 and uranium metal at 25 degree C leads mainly to the further oxidation of surface layer of metal due to traces of water vapour. At 200 degree C, it may lead to the hydriding reaction of uranium and the hydriding increases with increasing the exposure of H 2 . Investigation indicates CO inhibits both the hydriding reaction and oxidation on the condition of H 2 -CO atmospheres. (13 refs., 10 figs.)

  20. Phase transitions in polypeptides: analysis of energy fluctuations

    DEFF Research Database (Denmark)

    Yakubovich, Alexander V.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2009-01-01

    The helix random coil transition in alanine, valine, and leucine polypeptides consisting of 30 amino acids is studied in vacuo using the Langevin molecular dynamics approach. The influence of side chain radicals on internal energy and heat capacity of the polypeptides is discussed. The heat...... capacity of these polypeptides is calculated as a function of temperature using two different methods, namely, as the derivative of the energy with respect to temperature, and on the basis of energy fluctuations in the system. The convergence of the fluctuations based approach is analyzed as a function...... of simulation time. This study provides a comparison of methods for the description of structural transitions in polypeptides....

  1. [New drug developments of snake venom polypeptides and progress].

    Science.gov (United States)

    Fu, Sihai; Feng, Mei; Xiong, Yan

    2017-11-28

    The value of snake venom polypeptides in clinical application has drawn extensive attention, and the development of snake polypeptides into new drugs with anti-tumor, anti-inflammatory, antithrombotic, analgesic or antihypertensive properties has become the recent research hotspot. With the rapid development of molecular biology and biotechnology, the mechanisms of snake venom polypeptides are also gradually clarified. Numerous studies have demonstrated that snake venom polypeptides exert their pharmacological effects by regulating ion channels, cell proliferation, apoptosis, intracellular signaling pathway, and expression of cytokine as well as binding to relevant active sites or receptors.

  2. Detectability of H2-Ar and H2-Ne Dimers in Jovian Atmospheres

    Directory of Open Access Journals (Sweden)

    Young-Key Minn

    1997-12-01

    Full Text Available The detection of jovian hydrogen-hydrogen dimers through the clear telluric 2-micron window(Kim et al. 1995, Trafton et al. 1997 suggests possibility to detect noble gases in the form of dimer with hydrogen in jovian atmospheres. Since noble gases do not have spectral structures in the infrared, it has been difficult to derive their abundances in the atmospheres of jovian planets. If there is a significant component of noble gases other than helium in the jovian atmospheres. it might be detected through its dimer spectrum with hydrogen molecule. The relatively sharp spectral structures of hydrogen-argon and hydrogen-neon dimers compared with those of hydrogen-hydrogen dimers are useful for the detection, if an adequate signal-to-noise (S/N is obtained. If we use a large telescope, such as the Keck telescope, with a long exposure time (>24 hours, then H2-Ar spectral structure may be detected.

  3. Potential energy surface and rovibrational energy levels of the H2-CS van der Waals complex.

    Science.gov (United States)

    Denis-Alpizar, Otoniel; Stoecklin, Thierry; Halvick, Philippe; Dubernet, Marie-Lise; Marinakis, Sarantos

    2012-12-21

    Owing to its large dipole, astrophysicists use carbon monosulfide (CS) as a tracer of molecular gas in the interstellar medium, often in regions where H(2) is the most abundant collider. Predictions of the rovibrational energy levels of the weakly bound complex CS-H(2) (not yet observed) and also of rate coefficients for rotational transitions of CS in collision with H(2) should help to interpret the observed spectra. This paper deals with the first goal, i.e., the calculation of the rovibrational energy levels. A new four-dimensional intermolecular potential energy surface for the H(2)-CS complex is presented. Ab initio potential energy calculations were carried out at the coupled-cluster level with single and double excitations and a perturbative treatment of triple excitations, using a quadruple-zeta basis set and midbond functions. The potential energy surface was obtained by an analytic fit of the ab initio data. The equilibrium structure of the H(2)-CS complex is found to be linear with the carbon pointing toward H(2) at the intermolecular separation of 8.6 a(o). The corresponding well depth is -173 cm(-1). The potential was used to calculate the rovibrational energy levels of the para-H(2)-CS and ortho-H(2)-CS complexes. The present work provides the first theoretical predictions of these levels. The calculated dissociation energies are found to be 35.9 cm(-1) and 49.9 cm(-1), respectively, for the para and ortho complexes. The second virial coefficient for the H(2)-CS pair has also been calculated for a large range of temperature. These results could be used to assign future experimental spectra and to check the accuracy of the potential energy surface.

  4. Detection of Specific Polypeptide(s Synthesized during the Sequential Stages of Differentiation in Dioscorea species

    Directory of Open Access Journals (Sweden)

    Ashwani Kumar

    2015-10-01

    Full Text Available ABSTRACTThe present investigation was aimed to detect the specific polypeptide(s appeared during the sequential stages of differentiation. Among different explants, only nodal explants showed good results for callusing. Depending on the fresh and dry weight, best callus growth was observed on MS medium supplemented with NAA (2.5 mg/L inDioscorea alata and 2, 4-D (2.0 mg/L inD. deltoidea, respectively. This callus was used for the regeneration. Roots differentiation was observed on MS medium + NAA (2.0 mg/L + IBA (0.5 mg/L and shoots on MS medium + BAP (2.0 mg/L + NAA (0.5 mg/L in D. alata while in D. deltoidea, roots on RT medium + IAA (1.0 mg/L and shoots on RT medium + BAP (1.0 mg/L + NAA (0.5 mg/L. Continuous decrease was seen in the total soluble protein during the differentiation inD. alatawhereas inD. deltoidea, the protein content decreased upto initiation stage. Four root specific polypeptides (MW 25.56, 24.35, 19.13 and 18.2 kDa and three shoot specific polypeptides (MW 53.7, 25.12 and 19.13 kDa were synthesized during the differentiation inD. alata. Similarly, two root specific (MW 33.9 and 31.69 kDa and one shoot specific (MW 16.98 kDa polypeptide band were appeared during differentiation in D. deltoidea.

  5. Synthesis and crystal structure of hydrogen phosphites RbH2PO3, CsH2PO3, and TlH2PO3

    International Nuclear Information System (INIS)

    Kosterina, E.V.; Troyanov, S.I.; Kemnits, Eh.; Aslanov, L.A.

    2001-01-01

    The crystal acid phosphites RbH 2 PO 3 , CsH 2 PO 3 and TlH 2 PO 3 were separated during reaction of Rb, Cs and Tl carbonates with phosphorous acid solution. The crystal structure of the compounds was analyzed by X-ray diffraction method at 150 K. CsH 2 PO 3 has a monoclinic system, a = 7.930(2), b = 8.929(2), c = 13.163(3) A, β = 104.84(3) Deg, V = 900.9(4) A 3 , Z 8, sp. gr. P2 1 /c, R 1 = 0.239. In the structure hydrogen bonds integrate the PHO 3 tetrahedrons in the unlimited zigzag chains [HPHO 3 ] n n- laying at the layers, which are alternate to the layers of metal cations. The layers of anion chains have a wavy form [ru

  6. Diversification of histone H2A variants during plant evolution.

    Science.gov (United States)

    Kawashima, Tomokazu; Lorković, Zdravko J; Nishihama, Ryuichi; Ishizaki, Kimitsune; Axelsson, Elin; Yelagandula, Ramesh; Kohchi, Takayuki; Berger, Frederic

    2015-07-01

    Among eukaryotes, the four core histones show an extremely high conservation of their structure and form nucleosomes that compact, protect, and regulate access to genetic information. Nevertheless, in multicellular eukaryotes the two families, histone H2A and histone H3, have diversified significantly in key residues. We present a phylogenetic analysis across the green plant lineage that reveals an early diversification of the H2A family in unicellular green algae and remarkable expansions of H2A variants in flowering plants. We define motifs and domains that differentiate plant H2A proteins into distinct variant classes. In non-flowering land plants, we identify a new class of H2A variants and propose their possible role in the emergence of the H2A.W variant class in flowering plants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Untersuchungen am System NMMO/H2O/Cellulose

    OpenAIRE

    Cibik, T.

    2003-01-01

    Die vorliegende Arbeit befasst sich mit der Untersuchung des Zweistoffsystems N-Methylmorpholin-N-oxid (NMMO)/H2O und des Dreistoffsystems NMMO/H2O/Cellulose sowie mit der Herstellung und Charakterisierung von faserverstärkten Cellulosefolien. Das binäre System wird mittels Dynamischer Differenzkalorimetrie und Röntgenweitwinkel-Diffraktometrie untersucht und dadurch das Schmelzverhalten und die Phasenzusammensetzung dieses Systems im festen Zustand als Funktion des NMMO/H2O-Verhältnisses bes...

  8. Detonability of H2-air-diluent mixtures

    International Nuclear Information System (INIS)

    Tieszen, S.R.; Sherman, M.P.; Benedick, W.B.; Berman, M.

    1987-06-01

    This report describes the Heated Detonation Tube (HDT). Detonation cell width and velocity results are presented for H 2 -air mixtures, undiluted and diluted with CO 2 and H 2 O for a range of H 2 concentration, initial temperature and pressure. The results show that the addition of either CO 2 or H 2 O significantly increases the detonation cell width and hence reduces the detonability of the mixture. The results also show that the detonation cell width is reduced (detonability is increased) for increased initial temperature and/or pressure

  9. The Role of Endogenous H(2)S in Cardiovascular Physiology

    DEFF Research Database (Denmark)

    Skovgaard, Nini; Gouliaev, Anja; Aalling, Mathilde

    2011-01-01

    Recent research has shown that the endogenous gas hydrogen sulphide (H(2)S) is a signalling molecule of considerable biological potential and has been suggested to be involved in a vast number of physiological processes. In the vascular system, H(2)S is synthesized from cysteine by cystathionine...... in oxygen sensing. Furthermore, reduced endogenous H(2)S production may also play a role in ischemic heart diseases and hypertension, and treatment with H(2)S donors and cysteine analogues may be beneficial in treatment of cardiovascular disease....

  10. Biosynthesis and characterization of a non-repetitive polypeptide derived from silk fibroin heavy chain

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Gaoqiang; Wu, Mingyang; Yi, Honggen; Wang, Jiannan, E-mail: wangjn@suda.edu.cn

    2016-02-01

    Silk fibroin heavy chain is the major protein component of Bombyx mori silk fibroin and is composed of 12 repetitive and 11 non-repetitive regions, with the non-repetitive domain consisting of a hydrophilic polypeptide chain. In order to determine the biomedical function of the non-repetitive domain or potentially use it to modify hydrophobic biomaterials, high-purity isolation is necessary. Previously, we cloned and extended a gene motif (f(1)) encoding the non-repetitive domain. Here, this motif and its multimers are inserted into a glutathione S-transferase (GST)-tagged fusion-protein expression vector. Motif f(1) and multimers f(4) and f(8) were expressed in Escherichia coli BL21 cells following isopropyl β-D-1-thiogalactopyranoside induction, purified by GST-affinity chromatography, and single bands of purified fusion proteins GST-F(1), GST-F(4), and GST-F(8), were visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Target polypeptides F(1), F(4), and F(8), were cleaved clearly from the GST-fusion tag following thrombin digestion. Mass spectrometry results indicate that the molecular weights associated with fusion proteins GST-F(1), GST-F(4), and GST-F(8) are 31.5, 43.8, and 59.0 kDa, respectively, and with the cleaved polypeptides F(1), F(4), and F(8) are 4.8, 16.8, and 32.8 kDa, respectively. The F(1), F(4), and F(8) polypeptide chains are negatively charged with isoelectric points (pI) of 3.3, 3.2, and 3.0, respectively. The molecular weight and pI values of the polypeptide chains are consistent with the predicted values and the amino acid compositions similar to predicted sequences. FTIR and CD results show the molecular conformation of F(1) was mainly random coil, and more stable α-helix structure formed in longer molecular chain. - Highlights: • A non-repetitive domain and its multimers of silk fibroin were expressed by E. coli. • The corresponding target polypeptides F(1), F(4) and F(8) were cleaved clearly. • Their

  11. Relative importance of H2 and H2S as energy sources for primary production in geothermal springs.

    Science.gov (United States)

    D'Imperio, Seth; Lehr, Corinne R; Oduro, Harry; Druschel, Greg; Kühl, Michael; McDermott, Timothy R

    2008-09-01

    Geothermal waters contain numerous potential electron donors capable of supporting chemolithotrophy-based primary production. Thermodynamic predictions of energy yields for specific electron donor and acceptor pairs in such systems are available, although direct assessments of these predictions are rare. This study assessed the relative importance of dissolved H(2) and H(2)S as energy sources for the support of chemolithotrophic metabolism in an acidic geothermal spring in Yellowstone National Park. H(2)S and H(2) concentration gradients were observed in the outflow channel, and vertical H(2)S and O(2) gradients were evident within the microbial mat. H(2)S levels and microbial consumption rates were approximately three orders of magnitude greater than those of H(2). Hydrogenobaculum-like organisms dominated the bacterial component of the microbial community, and isolates representing three distinct 16S rRNA gene phylotypes (phylotype = 100% identity) were isolated and characterized. Within a phylotype, O(2) requirements varied, as did energy source utilization: some isolates could grow only with H(2)S, some only with H(2), while others could utilize either as an energy source. These metabolic phenotypes were consistent with in situ geochemical conditions measured using aqueous chemical analysis and in-field measurements made by using gas chromatography and microelectrodes. Pure-culture experiments with an isolate that could utilize H(2)S and H(2) and that represented the dominant phylotype (70% of the PCR clones) showed that H(2)S and H(2) were used simultaneously, without evidence of induction or catabolite repression, and at relative rate differences comparable to those measured in ex situ field assays. Under in situ-relevant concentrations, growth of this isolate with H(2)S was better than that with H(2). The major conclusions drawn from this study are that phylogeny may not necessarily be reliable for predicting physiology and that H(2)S can dominate over H(2

  12. Exploration of H2O-CO2 Solubility in Alkali Basalt at low-H2O

    Science.gov (United States)

    Roggensack, K.; Allison, C. M.; Clarke, A. B.

    2017-12-01

    A number of recent experimental studies have found conflicting evidence for and against the influence of H2O on CO2 solubility in basalt and alkali-rich mafic magma (e.g. Behrens et al., 2009; Shishkina et al., 2010;2014; Iacono-Marziano et al., 2012). Some of the uncertainty is due to the error with spectroscopic determination (FTIR) of carbon and the challenge of controlling H2O abundance in experiments. It's been widely observed that even experimental capsules without added H2O may produce hydrous glasses containing several wt.% H2O. We conducted fluid-saturated, mixed-fluid (H2O-CO2) experiments to determine the solubility in alkali basalt with particular emphasis on conditions at low-H2O. To limit possible H2O contamination, materials were dried prior to loading and experimental capsules were sealed under vacuum. Experiments were run using a piston-cylinder, in Pt (pre-soaked in Fe) or AuPd capsules and operating at pressures from 400 to 600 MPa. Post-run the capsules were punctured under vacuum and fluids were condensed, separated, and measured by mercury manometry. A comparison between two experiments run at the same temperature and pressure conditions but with different fluid compositions illustrates the correlation between carbonate and H2O solubility. Uncertainties associated with using concentrations calculated from FTIR data can be reduced by directly comparing analyses on wafers of similar thickness. We observe that the experiment with greater H2O absorbance also has a higher carbonate absorbance than the experiment with lower H2O absorbance. Since the experiments were run at the same pressure, the experiment with more water-rich fluid, and higher dissolved H2O, has lower CO2 fugacity, but surprisingly has higher dissolved CO2 content. Overall, the results show two distinct trends. Experiments conducted at low-H2O (0.5 to 0.8 wt.%) show lower dissolved CO2 than those conducted at moderate-H2O (2 to 3 wt.%) at similar CO2 fugacity. These data show that

  13. The tropospheric cycle of H2: a critical review

    Science.gov (United States)

    Ehhalt, D. H.; Rohrer, F.

    2009-07-01

    The literature on the distribution, budget and isotope content of molecular hydrogen (H2) in the troposphere is critically reviewed. The global distribution of H2 is reasonably well established and is relatively uniform. The surface measurements exhibit a weak latitudinal gradient with 3% higher concentrations in the Southern Hemisphere and seasonal variations that maximize in arctic latitudes and the interior of continents with peak-to-peak amplitudes up to 10%. There is no evidence for a continuous long-term trend, but older data suggest a reversal of the interhemispheric gradient in the late 1970s, and an increase in the deuterium content of H2 in the Northern Hemisphere from 80‰ standard mean ocean water (SMOW) in the 1970s to 130‰ today. The current budget analyses can be divided in two classes: bottom up, in which the source and sink terms are estimated separately based on emission factors and turnovers of precursors and on global integration of regional loss rates, respectively. That category includes the analyses by 3-D models and furnishes tropospheric turnovers around 75 Tg H2 yr-1. The other approach, referred to as top down, relies on inverse modelling or analysis of the deuterium budget of tropospheric H2. These provide a global turnover of about 105 Tg H2 yr-1. The difference is due to a much larger sink strength by soil uptake and a much larger H2 production from the photochemical oxidation of volatile organic compounds (VOC) in the case of the top down approaches. The balance of evidence seems to favour the lower estimates-mainly due to the constraint placed by the global CO budget on the H2 production from VOC. An update of the major source and sink terms yields: fossil fuel use 11 +/- 4 Tg H2 yr-1 biomass burning (including bio-fuel) 15 +/- 6 Tg H2 yr-1 nitrogen fixation (ocean) 6 +/- 3 Tg H2 yr-1 nitrogen fixation (land) 3 +/- 2 Tg H2 yr-1 photochemical production from CH4 23 +/- 8 Tg H2 yr-1 and photochemical production from other VOC 18

  14. (Solid + liquid) phase equilibria of (Ca(H2PO2)2 + CaCl2 + H2O) and (Ca(H2PO2)2 + NaH2PO2 + H2O) ternary systems at T = 323.15 K

    International Nuclear Information System (INIS)

    Cao, Hong-yu; Zhou, Huan; Bai, Xiao-qin; Ma, Ruo-xin; Tan, Li-na; Wang, Jun-min

    2016-01-01

    Graphical abstract: Solubility diagram of the (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) system at T = (323.15 and 298.15) K. - Highlights: • Phase diagrams of Ca 2+ -H 2 PO 2 − -Cl − -H 2 O, Ca 2+ -Na + -H 2 PO 2 − -H 2 O at 323.15 K were obtained. • Incompatible double salt of NaCa(H 2 PO 2 ) 3 in Ca 2+ -Na + -H 2 PO 2 − -H 2 O system was determined. • Density diagram of the corresponding liquid were simultaneously measured. - Abstract: Calcium hypophosphite has been widely used as an anti-corrosive agent, flame retardant, fertilizer, assistant for Ni electroless plating, and animal nutritional supplement. High purity calcium hypophosphite can be synthesized via the replacement reaction of sodium hypophosphite and calcium chloride. In this work, the (solid + liquid) phase equilibria of (Ca(H 2 PO 2 ) 2 + CaCl 2 + H 2 O) and (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) ternary systems at T = 323.15 K were studied experimentally via the classical isothermal solubility equilibrium method, and the phase diagrams for these two systems were obtained. It was found that two solid salts of CaCl 2 ·2H 2 O and Ca(H 2 PO 2 ) 2 exist in the (Ca(H 2 PO 2 ) 2 + CaCl 2 + H 2 O) system, and three salts of Ca(H 2 PO 2 ) 2 , NaH 2 PO 2 ·H 2 O and one incompatible double salt, NaCa(H 2 PO 2 ) 3 occur in the (Ca(H 2 PO 2 ) 2 + NaH 2 PO 2 + H 2 O) system.

  15. Electrochemical investigation of nickel pattern electrodes in H2/H2O and CO/CO2 atmospheres

    DEFF Research Database (Denmark)

    Ehn, A.; Høgh, Jens Valdemar Thorvald; Graczyk, M.

    2010-01-01

    In this study, nickel pattern electrodes were electrochemically investigated in a three-electrode setup, operating both with H2 / H2 O and CO/ CO2 atmospheres. Heating introduced structural differences in the nickel layer among the pattern electrodes, which appear to affect the electrode performa......In this study, nickel pattern electrodes were electrochemically investigated in a three-electrode setup, operating both with H2 / H2 O and CO/ CO2 atmospheres. Heating introduced structural differences in the nickel layer among the pattern electrodes, which appear to affect the electrode...... at lower temperatures in H2 / H2 O are also presented. Impedance spectroscopy measurements were performed, and the gas dependence of the polarization resistance was observed as the mixture ratios and temperatures were varied in both atmospheres. A positive relation between the polarization resistance...

  16. Interplay between Folding and Assembly of Fibril-Forming Polypeptides

    NARCIS (Netherlands)

    Ni, R.; Abeln, S.; Schor, M.; Cohen Stuart, M.A.; Bolhuis, P.G.

    2013-01-01

    Polypeptides can self-assemble into hierarchically organized fibrils consisting of a stack of individually folded polypeptides driven together by hydrophobic interaction. Using a coarse-grained model, we systematically studied this self-assembly as a function of temperature and hydrophobicity of the

  17. Enzyme-catalyzed synthesis of polyamides and polypeptides

    Science.gov (United States)

    Polyamides and polypeptides are important polymers in biological systems and industrial processes. Usually polyamides are produced via chemical synthesis, whereas polypeptides and proteins are isolated from living systems or produced from Merrifield synthesis. An area of active research is to use ...

  18. Measles virus-specified polypeptides in infected cells

    International Nuclear Information System (INIS)

    Vainionpaepae, R.

    1979-01-01

    The synthesis of wild-type measles virus-specified polypeptides in Vero cells in pulse-chase experiments, in cells with synchronized protein synthesis by high salt concentration, and in the presence of proteolytic enzyme inhibitors was analyzed by polyacrylamide slab-gel electrophoresis. Six major (L, G, 2, NP, 5 and M) structural polypeptides were identified in infected cells. The results of pulse-chase experiments suggested that most of the structural polypeptides were synthesized at their final length. Polypeptide M was found to be sensitive to trypsin. In TLCK-treated cells its molecular weight was about 1000-2000 daltons higher than in untreated cells. A minor virus-specific polypeptide with a molecular weight of about 23,000 was found as a very faint and diffuse band. In addition, three nonstructural polypeptides with molecular weights of 65,000, 38,000 and 18,000 were also detected. The experiments with proteolytic enzyme inhibitors and with synchronized protein synthesis suggested that the polypeptide with a molecular weight of 65,000 might be a precursor of the structural polypeptide 5. (author)

  19. Self-Driven Photoelectrochemical Splitting of H2S for S and H2Recovery and Simultaneous Electricity Generation.

    Science.gov (United States)

    Luo, Tao; Bai, Jing; Li, Jinhua; Zeng, Qingyi; Ji, Youzhi; Qiao, Li; Li, Xiaoyan; Zhou, Baoxue

    2017-11-07

    A novel, facile self-driven photoelectrocatalytic (PEC) system was established for highly selective and efficient recovery of H 2 S and simultaneous electricity production. The key ideas were the self-bias function between a WO 3 photoanode and a Si/PVC photocathode due to their mismatched Fermi levels and the special cyclic redox reaction mechanism of I - /I 3 - . Under solar light, the system facilitated the separation of holes in the photoanode and electrons in the photocathode, which then generated electricity. Cyclic redox reactions were produced in the photoanode region as follows: I - was transformed into I 3 - by photoholes or hydroxyl radicals, H 2 S was oxidized to S by I 3 - , and I 3 - was then reduced to I - . Meanwhile, H + was efficiently converted to H 2 in the photocathode region. In the system, H 2 S was uniquely oxidized to sulfur but not to polysulfide (S x n- ) because of the mild oxidation capacity of I 3 - . High recovery rates for S and H 2 were obtained up to ∼1.04 mg h -1 cm -1 and ∼0.75 mL h -1 cm -1 , respectively, suggesting that H 2 S was completely converted into H 2 and S. In addition, the output power density of the system reached ∼0.11 mW cm -2 . The proposed PEC-H 2 S system provides a self-sustaining, energy-saving method for simultaneous H 2 S treatment and energy recovery.

  20. Chirality-selected phase behaviour in ionic polypeptide complexes

    Science.gov (United States)

    Perry, Sarah L.; Leon, Lorraine; Hoffmann, Kyle Q.; Kade, Matthew J.; Priftis, Dimitrios; Black, Katie A.; Wong, Derek; Klein, Ryan A.; Pierce, Charles F.; Margossian, Khatcher O.; Whitmer, Jonathan K.; Qin, Jian; de Pablo, Juan J.; Tirrell, Matthew

    2015-01-01

    Polyelectrolyte complexes present new opportunities for self-assembled soft matter. Factors determining whether the phase of the complex is solid or liquid remain unclear. Ionic polypeptides enable examination of the effects of stereochemistry on complex formation. Here we demonstrate that chirality determines the state of polyelectrolyte complexes, formed from mixing dilute solutions of oppositely charged polypeptides, via a combination of electrostatic and hydrogen-bonding interactions. Fluid complexes occur when at least one of the polypeptides in the mixture is racemic, which disrupts backbone hydrogen-bonding networks. Pairs of purely chiral polypeptides, of any sense, form compact, fibrillar solids with a β-sheet structure. Analogous behaviour occurs in micelles formed from polypeptide block copolymers with polyethylene oxide, where assembly into aggregates with either solid or fluid cores, and eventually into ordered phases at high concentrations, is possible. Chirality is an exploitable tool for manipulating material properties in polyelectrolyte complexation. PMID:25586861

  1. Dissociation path for H2 on Al(110)

    DEFF Research Database (Denmark)

    Hammer, Bjørk; Jacobsen, Karsten Wedel; Nørskov, Jens Kehlet

    1992-01-01

    The minimum energy path is calculated for an H2 molecule dissociating on an Al(110) surface within local density functional theory. The properties of the potential energy surface along the five H2 ionic coordinates perpendicular to the reaction path are also determined and shown to be essential...

  2. Charge transfer in H2+-H(1s) collisions

    International Nuclear Information System (INIS)

    Errea, L.F.; Macias, A.; Mendez, L.; Rabadan, I.; Riera, A.

    2005-01-01

    We present an ab initio study of H 2 + +H(1s) collisions at H 2 + impact energies between 0.4 and 50keV. Cross sections are obtained within the sudden approximation for rotation and vibration of the diatomic molecule. We have found that anisotropy effects are crucial to correctly describe this system in this energy range

  3. Endogenous mitigation of H2S inside of the landfills.

    Science.gov (United States)

    Fang, Yuan; Zhong, Zhong; Shen, Dongsheng; Du, Yao; Xu, Jing; Long, Yuyang

    2016-02-01

    Vast quantities of hydrogen sulfide (H2S) emitted from landfill sites require urgent disposal. The current study focused on source control and examined the migration and conversion behavior of sulfur compounds in two lab-scale simulated landfills with different operation modes. It aimed to explore the possible strategies and mechanisms for H2S endogenous mitigation inside of landfills during decomposition. It was found that the strength of H2S emissions from the landfill sites was dependent on the municipal solid waste (MSW) degradation speed and vertical distribution of sulfide. Leachate recirculation can shorten both the H2S influence period and pollution risk to the surrounding environment. H2S endogenous mitigation may be achieved by chemical oxidation, biological oxidation, adsorption, and/or precipitation in different stages. Migration and conversion mainly affected H2S release behavior during the initial stabilization phase in the landfill. Microbial activities related to sulfur, nitrogen, and iron can further promote H2S endogenous mitigation during the high reducing phase. Thus, H2S endogenous mitigation can be effectively enhanced via control of the aforementioned processes.

  4. H2O Formation in C-rich AGB Winds

    NARCIS (Netherlands)

    Lombaert, R.; Decin, L.; Royer, P.; de Koter, A.; Cox, N.L.J.; De Ridder, J.; Khouri, T.; Agúndez, M.; Blommaert, J.A.D.L.; Gernicharo, J.; González-Alfonso, E.; Groenewegen, M.A.T.; Kerschbaum, F.; Neufeld, D.; Vandenbussche, B.; Waelkens, C.

    2015-01-01

    The Herschel detection of warm H2O vapor emission from C-rich winds of AGB stars challenges the current understanding of circumstellar chemistry. Two mechanisms have been invoked to explain warm H2O formation. In the first, penetration of UV interstellar radiation through a clumpy circumstellar

  5. Hormetic Effect of H2O2 in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Halyna M. Semchyshyn PhD

    2016-03-01

    Full Text Available In this study, we investigated the relationship between target of rapamycin (TOR and H2O2-induced hormetic response in the budding yeast Saccharomyces cerevisiae grown on glucose or fructose. In general, our data suggest that: (1 hydrogen peroxide (H2O2 induces hormesis in a TOR-dependent manner; (2 the H2O2-induced hormetic dose–response in yeast depends on the type of carbohydrate in growth medium; (3 the concentration-dependent effect of H2O2 on yeast colony growth positively correlates with the activity of glutathione reductase that suggests the enzyme involvement in the H2O2-induced hormetic response; and (4 both TOR1 and TOR2 are involved in the reciprocal regulation of the activity of glucose-6-phosphate dehydrogenase and glyoxalase 1.

  6. Fibrillar dimer formation of islet amyloid polypeptides

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, Chi-cheng [Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); de Pablo, Juan J. [Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-05-08

    Amyloid deposits of human islet amyloid polypeptide (hIAPP), a 37-residue hormone co-produced with insulin, have been implicated in the development of type 2 diabetes. Residues 20 – 29 of hIAPP have been proposed to constitute the amyloidogenic core for the aggregation process, yet the segment is mostly unstructured in the mature fibril, according to solid-state NMR data. Here we use molecular simulations combined with bias-exchange metadynamics to characterize the conformational free energies of hIAPP fibrillar dimer and its derivative, pramlintide. We show that residues 20 – 29 are involved in an intermediate that exhibits transient β-sheets, consistent with recent experimental and simulation results. By comparing the aggregation of hIAPP and pramlintide, we illustrate the effects of proline residues on inhibition of the dimerization of IAPP. The mechanistic insights presented here could be useful for development of therapeutic inhibitors of hIAPP amyloid formation.

  7. Fibrillar dimer formation of islet amyloid polypeptides

    Science.gov (United States)

    Chiu, Chi-cheng; de Pablo, Juan J.

    2015-09-01

    Amyloid deposits of human islet amyloid polypeptide (hIAPP), a 37-residue hormone co-produced with insulin, have been implicated in the development of type 2 diabetes. Residues 20 - 29 of hIAPP have been proposed to constitute the amyloidogenic core for the aggregation process, yet the segment is mostly unstructured in the mature fibril, according to solid-state NMR data. Here we use molecular simulations combined with bias-exchange metadynamics to characterize the conformational free energies of hIAPP fibrillar dimer and its derivative, pramlintide. We show that residues 20 - 29 are involved in an intermediate that exhibits transient β-sheets, consistent with recent experimental and simulation results. By comparing the aggregation of hIAPP and pramlintide, we illustrate the effects of proline residues on inhibition of the dimerization of IAPP. The mechanistic insights presented here could be useful for development of therapeutic inhibitors of hIAPP amyloid formation.

  8. Protein Encapsulation via Polypeptide Complex Coacervation

    Energy Technology Data Exchange (ETDEWEB)

    Black, Katie A.; Priftis, Dimitrios; Perry, Sarah L.; Yip, Jeremy; Byun, William Y.; Tirrell, Matthew

    2014-10-21

    Proteins have gained increasing success as therapeutic agents; however, challenges exist in effective and efficient delivery. In this work, we present a simple and versatile method for encapsulating proteins via complex coacervation with oppositely charged polypeptides, poly(L-lysine) (PLys) and poly(D/L-glutamic acid) (PGlu). A model protein system, bovine serum albumin (BSA), was incorporated efficiently into coacervate droplets via electrostatic interaction up to a maximum loading of one BSA per PLys/PGlu pair and could be released under conditions of decreasing pH. Additionally, encapsulation within complex coacervates did not alter the secondary structure of the protein. Lastly the complex coacervate system was shown to be biocompatible and interact well with cells in vitro. A simple, modular system for encapsulation such as the one presented here may be useful in a range of drug delivery applications.

  9. Oxidative stress status, antioxidant metabolism and polypeptide patterns in Juncus maritimus shoots exhibiting differential mercury burdens in Ria de Aveiro coastal lagoon (Portugal).

    Science.gov (United States)

    Anjum, Naser A; Duarte, Armando C; Pereira, Eduarda; Ahmad, Iqbal

    2014-05-01

    This study assessed the oxidative stress status, antioxidant metabolism and polypeptide patterns in salt marsh macrophyte Juncus maritimus shoots exhibiting differential mercury burdens in Ria de Aveiro coastal lagoon at reference and the sites with highest, moderate and the lowest mercury contamination. In order to achieve these goals, shoot-mercury burden and the responses of representative oxidative stress indices, and the components of both non-glutathione- and glutathione-based H2O2-metabolizing systems were analyzed and cross-talked with shoot-polypeptide patterns. Compared to the reference site, significant elevations in J. maritimus shoot mercury and the oxidative stress indices such as H2O2, lipid peroxidation, electrolyte leakage and reactive carbonyls were maximum at the site with highest followed by moderate and the lowest mercury contamination. Significantly elevated activity of non-glutathione-based H2O2-metabolizing enzymes such as ascorbate peroxidase and catalase accompanied the studied damage-endpoint responses, whereas the activity of glutathione-based H2O2-scavenging enzymes glutathione peroxidase and glutathione sulfo-transferase was inhibited. Concomitantly, significantly enhanced glutathione reductase activity and the contents of both reduced and oxidized glutathione were perceptible in high mercury-exhibiting shoots. It is inferred that high mercury-accrued elevations in oxidative stress indices were obvious, where non-glutathione-based H2O2-decomposing enzyme system was dominant over the glutathione-based H2O2-scavenging enzyme system. In particular, the glutathione-based H2O2-scavenging system failed to coordinate with elevated glutathione reductase which in turn resulted into increased pool of oxidized glutathione and the ratio of oxidized glutathione-to-reduced glutathione. The substantiation of the studied oxidative stress indices and antioxidant metabolism with approximately 53-kDa polypeptide warrants further studies.

  10. Methanol synthesis on potassium modified Cu(100) from CO + H2 and CO + CO2 +H2

    DEFF Research Database (Denmark)

    Maack, M.; Friis-Jensen, Henriette; Sckerl, Susanne Quist

    2003-01-01

    Methanol cannot be produced from CO + H-2 on a clean copper surface, but a promotional effect of potassium on methanol synthesis from mixtures of CO + H-2 and CO = CO2 + H-2 at a total pressure of 1.5 bar on a Cu(100) surface is shown in this work. The experiments are performed in a UHV chamber c....... Investigation of the post-reaction surface with TPD indicates that potassium carbonate is present and plays an important role. The activation energy is determined as 42 +/- 3 kJ/mol for methanol synthesis on K/Cu(100) from CO + H-2.......Methanol cannot be produced from CO + H-2 on a clean copper surface, but a promotional effect of potassium on methanol synthesis from mixtures of CO + H-2 and CO = CO2 + H-2 at a total pressure of 1.5 bar on a Cu(100) surface is shown in this work. The experiments are performed in a UHV chamber...... connected with a high-pressure cell (HPC). The methanol produced is measured with a gas chromatograph and the surface is characterized with surface science techniques. The results show that potassium is a promoter for the methanol synthesis from CO + H-2, and that the influence of CO2 is negligible...

  11. Mechanism and kinetics of LiX(X=H, D, T) + H2O reaction

    International Nuclear Information System (INIS)

    Lei Hongjie; Duan Hao; Xing Pifeng; Tang Yongjian

    2011-01-01

    The reaction mechanism of LiX(X=H, D, T) with H 2 O was investigated at MP2/6-311G (d) level using ab initio quantum chemistry in Gaussian 03 software. The equilibrium geometries, harmonic frequencies and energy of various stationary points on the potential energy surfaces were calculated in the lowest singlet states. Considering the quantum correction, the reaction rate constants were calculated using classical transition state theory. The results show the reaction of LiH (LiD, LiT) with H 2 O was considerably dependent on temperature that it is lower, the reaction rate constants are smaller. (authors)

  12. H2-independent growth of the hydrogenotrophic methanogen Methanococcus maripaludis.

    Science.gov (United States)

    Costa, Kyle C; Lie, Thomas J; Jacobs, Michael A; Leigh, John A

    2013-02-26

    Hydrogenotrophic methanogenic Archaea require reduced ferredoxin as an anaplerotic source of electrons for methanogenesis. H(2) oxidation by the hydrogenase Eha provides these electrons, consistent with an H(2) requirement for growth. Here we report the identification of alternative pathways of ferredoxin reduction in Methanococcus maripaludis that operate independently of Eha to stimulate methanogenesis. A suppressor mutation that increased expression of the glycolytic enzyme glyceraldehyde-3-phosphate:ferredoxin oxidoreductase resulted in a strain capable of H(2)-independent ferredoxin reduction and growth with formate as the sole electron donor. In this background, it was possible to eliminate all seven hydrogenases of M. maripaludis. Alternatively, carbon monoxide oxidation by carbon monoxide dehydrogenase could also generate reduced ferredoxin that feeds into methanogenesis. In either case, the reduced ferredoxin generated was inefficient at stimulating methanogenesis, resulting in a slow growth phenotype. As methanogenesis is limited by the availability of reduced ferredoxin under these conditions, other electron donors, such as reduced coenzyme F(420), should be abundant. Indeed, when F(420)-reducing hydrogenase was reintroduced into the hydrogenase-free mutant, the equilibrium of H(2) production via an F(420)-dependent formate:H(2) lyase activity shifted markedly toward H(2) compared to the wild type. Hydrogenotrophic methanogens are thought to require H(2) as a substrate for growth and methanogenesis. Here we show alternative pathways in methanogenic metabolism that alleviate this H(2) requirement and demonstrate, for the first time, a hydrogenotrophic methanogen that is capable of growth in the complete absence of H(2). The demonstration of alternative pathways in methanogenic metabolism suggests that this important group of organisms is metabolically more versatile than previously thought.

  13. Histamine H2 receptor - Involvement in gastric ulceration

    Science.gov (United States)

    Brown, P. A.; Vernikos-Danellis, J.; Brown, T. H.

    1976-01-01

    The involvement of the H1 and H2 receptors for histamine in the pathogenesis of gastric ulcers was investigated in rats. Metiamide, an H2 receptor antagonist, reliably reduced ulceration produced by stress alone or by a combination of stress and aspirin. In contrast, pyrilamine, which blocks only the H1 receptor, was without effect under these same conditions. The results support the hypothesis that histamine mediates both stress and stress plus aspirin induced ulceration by a mechanism involving the H2 receptor.

  14. Photoionization of H2O at high resolution

    International Nuclear Information System (INIS)

    Dehmer, P.M.; Chupka, W.A.

    1978-01-01

    The relative photoionization cross sections for the formation of H 2 O + , OH + , and H + from H 2 O were measured at high wavelength resolution using a 3-meter photoionization mass spectrometer equipped with a quadrupole mass flter and a 1-meter photoionization mass spectrometer equipped with a 12-inch radius, 60 0 sector magnetic mass spectrometer. Discrete structure in the parent ion photoionization efficiency curve is interpreted in terms of Rydberg series converging to excited states of the H 2 O + ion. 9 references

  15. Selective posttranslational modification of phage-displayed polypeptides

    Science.gov (United States)

    Tsao, Meng-Lin; Tian, Feng; Schultz, Peter

    2013-02-05

    The invention relates to posttranslational modification of phage-displayed polypeptides. These displayed polypeptides comprise at least one unnatural amino acid, e.g., an aryl-azide amino acid such as p-azido-L-phenylalanine, or an alkynyl-amino acid such as para-propargyloxyphenylalanine, which are incorporated into the phage-displayed fusion polypeptide at a selected position by using an in vivo orthogonal translation system comprising a suitable orthogonal aminoacyl-tRNA synthetase and a suitable orthogonal tRNA species. These unnatural amino acids advantageously provide targets for posttranslational modifications such as azide-alkyne [3+2]cycloaddition reactions and Staudinger modifications.

  16. Al-TiH2 Composite Foams Magnesium Alloy

    Science.gov (United States)

    Prasada Rao, A. K.; Oh, Y. S.; Ain, W. Q.; A, Azhari; Basri, S. N.; Kim, N. J.

    2016-02-01

    The work presented here in describes the synthesis of aluminum based titanium-hydride particulate composite by casting method and its foaming behavior of magnesium alloy. Results obtained indicate that the Al-10TiH2 composite can be synthesized successfully by casting method. Further, results also reveal that closed-cell magnesium alloy foam can be synthesized by using Al-10TiH2 composite as a foaming agent.

  17. The interstellar chemistry of H2C3O isomers.

    Science.gov (United States)

    Loison, Jean-Christophe; Agúndez, Marcelino; Marcelino, Núria; Wakelam, Valentine; Hickson, Kevin M; Cernicharo, José; Gerin, Maryvonne; Roueff, Evelyne; Guélin, Michel

    2016-03-11

    We present the detection of two H 2 C 3 O isomers, propynal and cyclopropenone, toward various starless cores and molecular clouds, together with upper limits for the third isomer propadienone. We review the processes controlling the abundances of H 2 C 3 O isomers in interstellar media showing that the reactions involved are gas-phase ones. We show that the abundances of these species are controlled by kinetic rather than thermodynamic effects.

  18. Phase Separation Kinetics in Isopycnic Mixtures of H2O/CO2/Ethoxylated Alcohol Surfactants

    Science.gov (United States)

    Lesemann, Markus; Paulaitis, Michael E.; Kaler, Eric W.

    1999-01-01

    Ternary mixtures of H2O and CO2 with ethoxylated alcohol (C(sub i)E(sub j)) surfactants form three coexisting liquid phases at conditions where two of the phases have equal densities (isopycnic phases). Isopycnic phase behavior has been observed for mixtures containing C8E5, C10E6, and C12E6 surfactants, but not for those mixtures containing either C4E1 or C8E3 surfactants. Pressure-temperature (PT) projections for this three-phase equilibrium were determined for H2O/CO2/C8E5 and H2O/CO2/C10E6 mixtures at temperatures from approximately 25 to 33 C and pressures between 90 and 350 bar. Measurements of the microstructure in H2O/CO2/C12E6 mixtures as a function of temperature (25-31 C), pressure (63.1-90.7 bar), and CO2 composition (0-3.9 wt%) have also been carried out to show that while micellar structure remains essentially un-changed, critical concentration fluctuations increase as the phase boundary and plait point are approached. In this report, we present our first measurements of the kinetics of isopycnic phase separation for ternary mixtures of H2O/CO2/C8E5.

  19. High H2O in MORB From Gakkel Ridge

    Science.gov (United States)

    Michael, P. J.; Matzen, A. K.; Langmuir, C. H.; Goldstein, S. L.; Soffer, G.; Schmieder, P.; Graham, D. W.

    2003-12-01

    Enriched and depleted mid-ocean ridge basalts (MORB) from western Gakkel Ridge (GR) in the Arctic Ocean have distinctive trace element and volatile characteristics compared to MORB globally. They are enriched in H2O and large ion lithophile (LIL) relative to rare earth elements (REE), so have high H2O/Ce and Ba/La. To a lesser degree, they are enriched in REE relative to HFS (e.g., high La/Nb). The order of enrichment is H2O >Ba>Rb>K>La and is similar to the subduction zone signature displayed by some back-arc basin basalts. There has been about 200 km of shortening in this region as Greenland converged with the Arctic Basin during the Cenozoic (Brozena et al, 2003) but true subduction is less likely. The enrichment pattern also has some similarity with continental lithosphere, which may be present in the source region since continental rifting was relatively recent in this region. Continental involvement was suggested for Knipovich R. (Schilling et al., 1999). The geographic extent of the distinctive enrichment should help constrain its origin, since an anomaly associated with Greenland convergence should be localized to western GR. H2O/Ce and Ba/La both diminish toward the eastern GR, where basalts resemble Pacific MORB.However, H2O/Ce remains high toward the North Atlantic along Knipovich, Mohns, Kolbeinsey and Reykjanes Ridges, suggesting a much larger region, perhaps related to a larger and more ancient subduction event. The extent of the high Ba/La in the northernmost Atlantic is not clear from current data. Isotopic data from Gakkel ridge MORB should provide additional constraints on the nature of the high- H2O component on GR. When MORB are considered globally, there are no consistent associations between H2O/Ce and other trace element and isotopic characteristics. Some MORB with high Ba/Nb and high 87Sr/86Sr relative to 206Pb/204Pb have high H2O (SEIR) whereas others (southern MAR) have distinctive low H2O (Dixon et al; 2002; Michael and Kamenetsky, 2002

  20. Molecular hydrogen (H2) emissions from gasoline and diesel vehicles.

    Science.gov (United States)

    Bond, S W; Alvarez, R; Vollmer, M K; Steinbacher, M; Weilenmann, M; Reimann, S

    2010-08-01

    This study assesses individual-vehicle molecular hydrogen (H2) emissions in exhaust gas from current gasoline and diesel vehicles measured on a chassis dynamometer. Absolute H2 emissions were found to be highest for motorcycles and scooters (141+/-38.6 mg km(-1)), approximately 5 times higher than for gasoline-powered automobiles (26.5+/-12.1 mg km(-1)). All diesel-powered vehicles emitted marginal amounts of H2 ( approximately 0.1 mg km(-1)). For automobiles, the highest emission factors were observed for sub-cycles subject to a cold-start (mean of 53.1+/-17.0 mg km(-1)). High speeds also caused elevated H2 emission factors for sub-cycles reaching at least 150 km h(-1) (mean of 40.4+/-7.1 mg km(-1)). We show that H2/CO ratios (mol mol(-1)) from gasoline-powered vehicles are variable (sub-cycle means of 0.44-5.69) and are typically higher (mean for automobiles 1.02, for 2-wheelers 0.59) than previous atmospheric ratios characteristic of traffic-influenced measurements. The lowest mean individual sub-cycle ratios, which correspond to high absolute emissions of both H2 and CO, were observed during cold starts (for automobiles 0.48, for 2-wheelers 0.44) and at high vehicle speeds (for automobiles 0.73, for 2-wheelers 0.45). This finding illustrates the importance of these conditions to observed H2/CO ratios in ambient air. Overall, 2-wheelers displayed lower H2/CO ratios (0.48-0.69) than those from gasoline-powered automobiles (0.75-3.18). This observation, along with the lower H2/CO ratios observed through studies without catalytic converters, suggests that less developed (e.g. 2-wheelers) and older vehicle technologies are largely responsible for the atmospheric H2/CO ratios reported in past literature. 2010 Elsevier B.V. All rights reserved.

  1. Islet Amyloid Polypeptide: Structure, Function, and Pathophysiology

    Directory of Open Access Journals (Sweden)

    Rehana Akter

    2016-01-01

    Full Text Available The hormone islet amyloid polypeptide (IAPP, or amylin plays a role in glucose homeostasis but aggregates to form islet amyloid in type-2 diabetes. Islet amyloid formation contributes to β-cell dysfunction and death in the disease and to the failure of islet transplants. Recent work suggests a role for IAPP aggregation in cardiovascular complications of type-2 diabetes and hints at a possible role in type-1 diabetes. The mechanisms of IAPP amyloid formation in vivo or in vitro are not understood and the mechanisms of IAPP induced β-cell death are not fully defined. Activation of the inflammasome, defects in autophagy, ER stress, generation of reactive oxygen species, membrane disruption, and receptor mediated mechanisms have all been proposed to play a role. Open questions in the field include the relative importance of the various mechanisms of β-cell death, the relevance of reductionist biophysical studies to the situation in vivo, the molecular mechanism of amyloid formation in vitro and in vivo, the factors which trigger amyloid formation in type-2 diabetes, the potential role of IAPP in type-1 diabetes, the development of clinically relevant inhibitors of islet amyloidosis toxicity, and the design of soluble, bioactive variants of IAPP for use as adjuncts to insulin therapy.

  2. Different reaction of the core histones H2A and H2B to red laser irradiation

    Science.gov (United States)

    Brill, G. E.; Egorova, A. V.; Bugaeva, I. O.; Postnov, D. E.; Ushakova, O. V.

    2017-03-01

    Analysis of the influence of red laser irradiation on the processes of self-assembly of the core histones H2A and H2B was performed using a wedge dehydration method. Image-analysis of facies included their qualitative characteristics and calculation of quantitative parameters with subsequent statistical processing. It was established that linearly polarized red laser light (λ - 660 nm, 1 J/cm2) significantly modified the process of self-assembly of core histone H2B, whereas the structure of the facies of H2A histone changed to a lesser extent. Histones were used in the form of aqueous salt solutions. The effect of red light seems to result from the formation of singlet oxygen by direct laser excitation of molecular oxygen.

  3. Interaction between sulphide and H 2O in silicate melts

    Science.gov (United States)

    Stelling, Jan; Behrens, Harald; Wilke, Max; Göttlicher, Jörg; Chalmin-Aljanabi, Emilie

    2011-06-01

    Reaction between dissolved water and sulphide was experimentally investigated in soda-lime-silicate (NCS) and sodium trisilicate (NS3) melts at temperatures from 1000 to 1200 °C and pressures of 100 or 200 MPa in internally heated gas pressure vessels. Diffusion couple experiments were conducted at water-undersaturated conditions with one half of the couple being doped with sulphide (added as FeS or Na 2S; 1500-2000 ppm S by weight) and the other with H 2O (˜3.0 wt.%). Additionally, two experiments were performed using a dry NCS glass cylinder and a free H 2O fluid. Here, the melt was water-saturated at least at the melt/fluid interface. Profiling by electron microprobe (sulphur) and infrared microscopy (H 2O) demonstrate that H 2O diffusion in the melts is faster by 1.5-2.3 orders of magnitude than sulphur diffusion and, hence, H 2O can be considered as a rapidly diffusing oxidant while sulphur is quasi immobile in these experiments. In Raman spectra a band at 2576 cm -1 appears in the sulphide - H 2O transition zone which is attributed to fundamental S-H stretching vibrations. Formation of new IR absorption bands at 5025 cm -1 (on expense of the combination band of molecular H 2O at 5225 cm -1) and at 3400 cm -1 was observed at the front of the in-diffusing water in the sulphide bearing melt. The appearance and intensity of these two IR bands is correlated with systematic changes in S K-edge XANES spectra. A pre-edge excitation at 2466.5 eV grows with increasing H 2O concentration while the sulphide peak at 2474.0 eV decreases in intensity relative to the peak at 2477.0 eV and the feature at 2472.3 eV becomes more pronounced (all energies are relative to the sulphate excitation, calibrated to 2482.5 eV). The observations by Raman, IR and XANES spectroscopy indicate a well coordinated S 2- - H 2O complex which was probably formed in the glasses during cooling at the glass transition. No oxidation of sulphide was observed in any of the diffusion couple

  4. Salt- and pH-Triggered Helix-Coil Transition of Ionic Polypeptides under Physiology Conditions.

    Science.gov (United States)

    Yuan, Jingsong; Zhang, Yi; Sun, Yue; Cai, Zhicheng; Yang, Lijiang; Lu, Hua

    2018-03-26

    Controlling the helix-coil transition of polypeptides under physiological conditions is an attractive way toward smart functional materials. Here we report the synthesis of a series of tertiary amine-functionalized ethylene glycol (EGx)-linked polypeptide electrolytes with their secondary structures tunable under physiological conditions. The resultant polymers, denoted as P(EGxDMA-Glu) (x =1, 2, and 3), show excellent aqueous solubility (> 10 mg/mL) regardless of their charge states. Unlike poly-L-lysine that can form helix only at pH above 10, P(EGxDMA-Glu) undergo a pH-dependent helix-coil switch with their transition points within physiological range (~ pH 5.3-6.5). Meanwhile, P(EGxDMA-Glu) exhibit unusual salt-induced helical conformation presumably owing to the unique properties of EGx linkers. Together, the current work highlights the importance of fine-tuning the linker chemistry in achieving conformation-switchable polypeptides, and represents a facile approach towards stimuli-responsive biopolymers for advanced biological applications.

  5. Observations of interstellar H2O emission at 183 Gigahertz

    International Nuclear Information System (INIS)

    Waters, J.W.; Gustincic, J.J.; Kakar, R.K.; Kuiper, T.B.H.; Roscoe, H.K.; Swanson, P.N.; Rodriguez Kuiper, E.N.; Kerr, A.R.; Thaddeus, P.

    1980-01-01

    Line emission at 183 GHz by the 3 13 --2 20 rotational transition of water vapor has been detected from the Orion Nebula with the NASA Kuiper Airborne Observatory 91 cm telescope. The peak antenna temperature of the line is 15 K, its LSR velocity is 8 km s -1 , and its width is 15 km s -1 . The velocity profile has characteristics similar to those for CO:a narrow (approx.4 km s -1 ) ''spike'' centered at 9.5 km s -1 and a broad ''plateau'' with flaring wings centered at approx.8 km s -1 . Our 7'.5 antenna beam did not resolve the source. The 183 GHz H 2 O plateau emission appears enhanced above that expected for thermal excitation if it originates from the no greater than 1' region characteristic of plateau emission from all other observed molecules. The spike emission is consistent with an optically thick source of the approximated size of the well-known molecular ridge in Orion having the H 2 O in thermal equilibrium at Tapprox. =50 K. If this is the case, then the H 2 O column density giving rise to the spike is N/sub H/2/sub O/> or =3 x 10 17 cm -2 . An excitation calculation implies N/sub H/2/sub O/approx. =10 18 cm -2 for a source the size of the molecular ridge. These results imply that H 2 O is one of the more abundant species in the Orion Molecualr Cloud.H 2 O emission at 183 GHz was not detected in Sgr A, Sgr B2, W3, W43, W49, W51, DR 21, NGC 1333, NGC 7027, GL 2591, or the rho Oph cloud; it may have been detected in M17

  6. Clustering of H2 molecules encapsulated in fullerene structures

    Science.gov (United States)

    Barajas-Barraza, R. E.; Guirado-López, R. A.

    2002-10-01

    We have performed semiempirical (MNDO) as well as ab initio density-functional theory calculations at T=0 to analyze the hydrogen storage behavior in spheroidal C60 and C82, and cylindrical finite-length (5,5) armchair C and BN fullerenes. We have found that, while chemisorption of individual H atoms to the external surface of the fullerenes is observed, hydrogen atoms cannot be attached to the inner wall of the structures and can only exist in a molecular form inside the fullerenes. We further find that, as a function of the symmetry of the encapsulating cavity and a delicate balance between repulsive energies among H2 molecules inside the structures and those between H2 molecules and the fullerene walls, molecular (H2)N clusters of well defined shape are formed namely: linear configurations, two-dimensional zig-zag and triangular arrays, and three-dimensional structures such as octahedral and icosahedral clusters, as well as helicoidal cylindrical-shape assemblies. In the cylindrical configurations (C and BN tubes), hydrogen atoms are placed inside the structures up to a bond breakage of the fullerene network, which allow us to estimate the maximum storage capacities of the different configurations. Actually, in our closed nanotubes, we relate the bond breakage mechanism to the development of a nonuniform hydrogen accommodation along the tubes, driven by the both highly anisotropic H2-H2 and wall-H2 repulsive interactions. With increasing the number of stored H2, tubes are found to be mainly radially deformed, a fact that reduces (up to ~13%) the energy difference between the highest occupied and lowest unoccupied molecular orbitals in the structures. Finally, saturation of the tube ends with molecular terminations results in stable compounds from which a density-controlled storage of hydrogen seems to be possible.

  7. BIOSIGNATURE GASES IN H2-DOMINATED ATMOSPHERES ON ROCKY EXOPLANETS

    International Nuclear Information System (INIS)

    Seager, S.; Bains, W.; Hu, R.

    2013-01-01

    Super-Earth exoplanets are being discovered with increasing frequency and some will be able to retain stable H 2 -dominated atmospheres. We study biosignature gases on exoplanets with thin H 2 atmospheres and habitable surface temperatures, using a model atmosphere with photochemistry and a biomass estimate framework for evaluating the plausibility of a range of biosignature gas candidates. We find that photochemically produced H atoms are the most abundant reactive species in H 2 atmospheres. In atmospheres with high CO 2 levels, atomic O is the major destructive species for some molecules. In Sun-Earth-like UV radiation environments, H (and in some cases O) will rapidly destroy nearly all biosignature gases of interest. The lower UV fluxes from UV-quiet M stars would produce a lower concentration of H (or O) for the same scenario, enabling some biosignature gases to accumulate. The favorability of low-UV radiation environments to accumulate detectable biosignature gases in an H 2 atmosphere is closely analogous to the case of oxidized atmospheres, where photochemically produced OH is the major destructive species. Most potential biosignature gases, such as dimethylsulfide and CH 3 Cl, are therefore more favorable in low-UV, as compared with solar-like UV, environments. A few promising biosignature gas candidates, including NH 3 and N 2 O, are favorable even in solar-like UV environments, as these gases are destroyed directly by photolysis and not by H (or O). A more subtle finding is that most gases produced by life that are fully hydrogenated forms of an element, such as CH 4 and H 2 S, are not effective signs of life in an H 2 -rich atmosphere because the dominant atmospheric chemistry will generate such gases abiologically, through photochemistry or geochemistry. Suitable biosignature gases in H 2 -rich atmospheres for super-Earth exoplanets transiting M stars could potentially be detected in transmission spectra with the James Webb Space Telescope

  8. Different reaction of core histones H2A and H2B to the red laser radiation

    Directory of Open Access Journals (Sweden)

    Brill G.E.

    2017-09-01

    Full Text Available Aim: to investigate the influence of red laser irradiation on the processes of self-assembly of core histones H2A and H2B. Material and Methods. Solutions of human histone proteins were used in the work. Self-assembly was studied by the method of wedge dehydration. Image facies analysis consisted in their qualitative characterization and calculation of quantitative indicators with subsequent statistical processing. Results. It was established that linearly polarized laser light of the red region of the spectrum (A=660 nm, 1 J/cm2 significantly modifies the process of self-assembly of core histone H2B, while the structure of the facies of H2A histone changing to a lesser extent. Conclusion. Red laser radiation influences on the on the processes of self-assembly of core histones H2A and H2B. There is a differential sensitivity of different classes of histones to laser action. Histone proteins used in the experiments are present in the form of aqueous salt solutions. Red light realizes the effect seems to be due to the formation of singlet oxygen by direct laser excitation of molecular oxygen.

  9. Investigation of the Na2(H2PO2)2 - Ba(H2PO2)2 - H2O Water-Salt Ternary System at Room Temperature

    OpenAIRE

    Erge, Hasan; Turan, Hakan; Kul, Ali Riza

    2016-01-01

    Objective: In this study, the solubility, density, conductivity and phase equilibria of the Na2(H2PO2)2-Ba(H2PO2)2-H2O ternary system located in the structure of the Na+, Ba2+, (H2PO2)-//H2O quaternary reciprocal water-salt system were investigated using physicochemical analysis methods. Material and Methods: Riedel-de Haen and Merck salts were used to investigate the solubility and phase equilibria of the Na2(H2PO2)2 -Ba(H2PO2)2-H2O ternary water–salt system at room temperature Res...

  10. Controlling assembly of helical polypeptides via PEGylation strategies†

    Science.gov (United States)

    Top, Ayben; Zhong, Sheng; Yan, Congqi

    2013-01-01

    Recent studies in our laboratories have demonstrated that a helical polypeptide (17H6), equipped with a histidine tag and a helical alanine-rich, glutamic-acid-containing domain, exhibits pH-responsive assembly behavior useful in the production of polymorphological nanostructures. In this study, the histidine tag in these polypeptides was replaced by polyethylene glycol (PEG) with different molecular masses (5 kDa, or 10 kDa), and the self-association behavior of 17H6 and the PEGylated conjugates was characterized via dynamic light scattering (DLS), small angle neutron scattering (SANS), and cryogenic transmission electron microscopy (cryo-TEM). DLS experiments illustrated that the polypeptide and its PEG-conjugates undergo reversible assembly under acidic conditions, suggesting that the aggregation state of the polypeptide and the conjugates is controlled by the charged state of the glutamic acid residues. Nanoscale aggregates were detected at polypeptide/conjugate concentrations as low as 20 μM (∼0.3–0.5 mg ml−1) at physiological and ambient temperatures. Scattering and microscopy results showed that the size, the aggregation number, and the morphology of the aggregates can be tuned by the size and the nature of the hydrophilic tag. This tunable nature of the morphology of the aggregates, along with their low critical aggregation concentration, suggests that PEG-alanine-rich polypeptide conjugates may be useful as drug delivery vehicles in which the alanine-rich block serves as a drug attachment domain. PMID:24039625

  11. Biosynthesis of the neural cell adhesion molecule: characterization of polypeptide C

    DEFF Research Database (Denmark)

    Nybroe, O; Albrechtsen, M; Dahlin, J

    1985-01-01

    The biosynthesis of the neural cell adhesion molecule (N-CAM) was studied in primary cultures of rat cerebral glial cells, cerebellar granule neurons, and skeletal muscle cells. The three cell types produced different N-CAM polypeptide patterns. Glial cells synthesized a 135,000 Mr polypeptide B...... and a 115,000 Mr polypeptide C, whereas neurons expressed a 200,000 Mr polypeptide A as well as polypeptide B. Skeletal muscle cells produced polypeptide B. The polypeptides synthesized by the three cell types were immunochemically identical. The membrane association of polypeptide C was investigated...... with methods that distinguish peripheral and integral membrane proteins. Polypeptide C was found to be a peripheral membrane protein, whereas polypeptides A and B were integral membrane proteins with cytoplasmic domains of approximately 50,000 and approximately 25,000 Mr, respectively. The affinity...

  12. The H+3 + H2 isotopic system. Origin of deuterium astrochemistry

    International Nuclear Information System (INIS)

    Hugo, Edouard Jean-Marie

    2008-01-01

    Dense cold molecular clouds reckoned to be stellar nurseries are the scene of an extreme molecular deuteration. Despite the cosmic D/H ratio of ∝10 -5 , molecular species in prestellar cores are observed to contain nearly as much deuterium as hydrogen. This astonishing deuterium enrichment promoted by low temperatures is the work of H + 3 . It is the key species which unlocks the deuterium from its HD reservoir via reactions like H + 3 +HD ↔ H 2 D + +H 2 and drags it further to other species in successive reactions. For this reason, the H + 3 +H 2 isotopic system is outstandingly critical for the astrochemistry of cold environments. However, its understanding is yet incomplete and insufficient. This thesis thus focuses on the H + 3 +H 2 isotopic system from a theoretical, experimental and astronomical point of view giving a particular look into the role of nuclear spins. As a first step, the stringent nuclear spin selection rules in associative, dissociative and reactive collisions are investigated. This purely theoretical study zooms into the details of the nuclear spin wavefunctions and shows that their permutation symmetry representation is necessary and sufficient, contrary to their angular momentum representation. Additionally, a new deterministic interpretation of nuclear spins in chemical reactions is proposed. Based on these considerations, a complete set of state-to-state rate coefficients for all H + 3 + H 2 isotopic variants is calculated using a microcanonical model leaned on phase space theory. An experimental study is conducted in parallel with a 22-pole ion trap apparatus in order to inspect the influences of temperature and H 2 ortho-to-para ratio. The good overall agreement between experimental and theoretical results supports the validity and utility of the calculated set of rate coefficients. Furthermore, the potentiality of the 22-pole ion trap apparatus is explored via the Laser Induced Reaction (LIR) technique applied to our system of

  13. Indications for the use of parenteral H2-receptor antagonists.

    Science.gov (United States)

    Thompson, J C; Walker, J P

    1984-11-19

    Development of acute mucosal ulceration is a complex series of catabolic interactions. Hospitalized patients with duodenal or gastric ulcer, pathologic gastric hypersecretory states (such as Zollinger-Ellison syndrome), gastric outlet obstruction, esophagitis, severe gastritis or duodenitis, sepsis, trauma (particularly head injury or burns), and some patients receiving high-dose corticosteroids are at risk of developing acute stress ulcers. Treatment should be initiated as soon as the patient is identified as being at risk, because measures designed to prevent bleeding or perforation are more effective than those designed to stop bleeding once it supervenes and the cascade of multiple organ failure commences. The presence of acid will trigger the onset of this condition; however, ulceration will not occur if the intraluminal pH can be maintained above 5 by periodic antacid treatment or by H2-receptor blockade. The dosing regimen of antacid or of H2-receptor antagonist should not be fixed, but should be sufficient to keep the gastric pH higher than 5. Antagonists administered via a nasogastric tube are the first line of defense, but 30 to 50 percent of the most ill patients will also be treated parenterally with H2-receptor antagonists. Parenteral H2-receptor blockade therapy is indicated in these patients when the risk of acute or continued ulceration of esophageal, gastric, or duodenal mucosa is high and the oral administration of medication is either not possible or the response to such therapy is unreliable. Parenteral H2-receptor antagonists are rarely administered alone.

  14. Electrochemical, H2O2-Boosted Catalytic Oxidation System

    Science.gov (United States)

    Akse, James R.; Thompson, John O.; Schussel, Leonard J.

    2004-01-01

    An improved water-sterilizing aqueous-phase catalytic oxidation system (APCOS) is based partly on the electrochemical generation of hydrogen peroxide (H2O2). This H2O2-boosted system offers significant improvements over prior dissolved-oxygen water-sterilizing systems in the way in which it increases oxidation capabilities, supplies H2O2 when needed, reduces the total organic carbon (TOC) content of treated water to a low level, consumes less energy than prior systems do, reduces the risk of contamination, and costs less to operate. This system was developed as a variant of part of an improved waste-management subsystem of the life-support system of a spacecraft. Going beyond its original intended purpose, it offers the advantage of being able to produce H2O2 on demand for surface sterilization and/or decontamination: this is a major advantage inasmuch as the benign byproducts of this H2O2 system, unlike those of systems that utilize other chemical sterilants, place no additional burden of containment control on other spacecraft air- or water-reclamation systems.

  15. Application of parametric equations of motion to study the resonance coalescence in H2(+).

    Science.gov (United States)

    Kalita, Dhruba J; Gupta, Ashish K

    2012-12-07

    Recently, occurrence of coalescence point was reported in H(2)(+) undergoing multiphoton dissociation in strong laser field. We have applied parametric equations of motion and smooth exterior scaling method to study the coalescence phenomenon of H(2)(+). The advantage of this method is that one can easily trace the different states that are changing as the field parameters change. It was reported earlier that in the parameter space, only two bound states coalesce [R. Lefebvre, O. Atabek, M. Sindelka, and N. Moiseyev, Phys. Rev. Lett. 103, 123003 (2009)]. However, it is found that increasing the accuracy of the calculation leads to the coalescence between resonance states originating from the bound and the continuum states. We have also reported many other coalescence points.

  16. TriPer, an optical probe tuned to the endoplasmic reticulum tracks changes in luminal H2O2.

    Science.gov (United States)

    Melo, Eduardo Pinho; Lopes, Carlos; Gollwitzer, Peter; Lortz, Stephan; Lenzen, Sigurd; Mehmeti, Ilir; Kaminski, Clemens F; Ron, David; Avezov, Edward

    2017-03-27

    The fate of hydrogen peroxide (H 2 O 2 ) in the endoplasmic reticulum (ER) has been inferred indirectly from the activity of ER-localized thiol oxidases and peroxiredoxins, in vitro, and the consequences of their genetic manipulation, in vivo. Over the years hints have suggested that glutathione, puzzlingly abundant in the ER lumen, might have a role in reducing the heavy burden of H 2 O 2 produced by the luminal enzymatic machinery for disulfide bond formation. However, limitations in existing organelle-targeted H 2 O 2 probes have rendered them inert in the thiol-oxidizing ER, precluding experimental follow-up of glutathione's role in ER H 2 O 2 metabolism. Here we report on the development of TriPer, a vital optical probe sensitive to changes in the concentration of H 2 O 2 in the thiol-oxidizing environment of the ER. Consistent with the hypothesized contribution of oxidative protein folding to H 2 O 2 production, ER-localized TriPer detected an increase in the luminal H 2 O 2 signal upon induction of pro-insulin (a disulfide-bonded protein of pancreatic β-cells), which was attenuated by the ectopic expression of catalase in the ER lumen. Interfering with glutathione production in the cytosol by buthionine sulfoximine (BSO) or enhancing its localized destruction by expression of the glutathione-degrading enzyme ChaC1 in the lumen of the ER further enhanced the luminal H 2 O 2 signal and eroded β-cell viability. A tri-cysteine system with a single peroxidatic thiol enables H 2 O 2 detection in oxidizing milieux such as that of the ER. Tracking ER H 2 O 2 in live pancreatic β-cells points to a role for glutathione in H 2 O 2 turnover.

  17. Mapping of polypeptides encoded by the Epstein-Barr virus genome in productive infection.

    OpenAIRE

    Hummel, M; Kieff, E

    1982-01-01

    Over 30 viral-specified polypeptides are translated in vitro from RNA of cells productively infected with Epstein-Barr virus (EBV). The polypeptides map to sites in EBV DNA by hybrid selection. Almost all of the polypeptides are reactive with EBV immune human serum. Several of the polypeptides are part of the early antigen complex. Two others are likely to be major structural components of the virus. Genes encoding persistent early and late polypeptides are intermixed through most of the EBV ...

  18. Mutations in non-acid patch residues disrupt H2A.Z's association with chromatin through multiple mechanisms.

    Directory of Open Access Journals (Sweden)

    Thomas J Wood

    Full Text Available The incorporation of histone variants into nucleosomes is a critical mechanism for regulating essential DNA-templated processes and for establishing distinct chromatin architectures with specialised functions. H2A.Z is an evolutionarily conserved H2A variant that has diverse roles in transcriptional regulation, heterochromatin boundary definition, chromosome stability and DNA repair. The H2A.Z C-terminus diverges in sequence from canonical H2A and imparts unique functions to H2A.Z in the yeast S. cerevisiae. Although mediated in part through the acid patch-containing M6 region, many molecular determinants of this divergent structure-function relationship remain unclear. Here, by using an unbiased random mutagenesis screen of H2A.Z alleles, we identify point mutations in the C-terminus outside of the M6 region that disrupt the normal function of H2A.Z in response to cytotoxic stress. These functional defects correlate with reduced chromatin association, which we attribute to reduced physical stability within chromatin, but also to altered interactions with the SWR and INO80 chromatin remodeling complexes. Together with experimental data, computational modelling of these residue changes in the context of protein structure suggests the importance of C-terminal domain integrity and configuration for maintaining the level of H2A.Z in nucleosomes.

  19. Intravenous infusion of H2-saline suppresses oxidative stress and elevates antioxidant potential in Thoroughbred horses after racing exercise.

    Science.gov (United States)

    Yamazaki, Masahiko; Kusano, Kanichi; Ishibashi, Toru; Kiuchi, Masataka; Koyama, Katsuhiro

    2015-10-23

    Upon intensive, exhaustive exercise, exercise-induced reactive oxygen species may exceed the antioxidant defence threshold, consequently resulting in muscular damage or late-onset chronic inflammation. Recently, the therapeutic antioxidant and anti-inflammatory effects of molecular hydrogen (H2) for human rheumatoid arthritis have been demonstrated. However, it is also important to clarify the effects of administrating H2 in large animals other than humans, as H2 is thought to reach the target organ by passive diffusion upon delivery from the blood flow, indicating that the distance from the administration point to the target is critical. However, data on the effects of H2 on oxidative stress in real-life exhaustive exercise in large animals are currently lacking. We here investigated 13 Thoroughbred horses administered intravenous 2-L saline with or without 0.6-ppm H2 (placebo, N = 6; H2, N = 7) before participating in a high-intensity simulation race. Intravenous H2-saline significantly suppressed oxidative stress immediately, 3 h, and 24 h after the race, although the antioxidant capability was not affected throughout the study. The serum creatine kinase, lactate, and uric acid levels were increased in both groups. Taken together, these results indicate that intravenous H2-saline can significantly and specifically suppress oxidative stress induced after exhaustive racing in Thoroughbred horses.

  20. H∞ /H2 model reduction through dilated linear matrix inequalities

    DEFF Research Database (Denmark)

    Adegas, Fabiano Daher; Stoustrup, Jakob

    2012-01-01

    This paper presents sufficient dilated linear matrix inequalities (LMI) conditions to the $H_{infty}$ and $H_{2}$ model reduction problem. A special structure of the auxiliary (slack) variables allows the original model of order $n$ to be reduced to an order $r=n/s$ where $n,r,s in field{N}$. Arb......This paper presents sufficient dilated linear matrix inequalities (LMI) conditions to the $H_{infty}$ and $H_{2}$ model reduction problem. A special structure of the auxiliary (slack) variables allows the original model of order $n$ to be reduced to an order $r=n/s$ where $n,r,s in field...... not satisfactorily approximates the original system, an iterative algorithm based on dilated LMIs is proposed to significantly improve the approximation bound. The effectiveness of the method is accessed by numerical experiments. The method is also applied to the $H_2$ order reduction of a flexible wind turbine...

  1. Data-Driven Controller Design The H2 Approach

    CERN Document Server

    Sanfelice Bazanella, Alexandre; Eckhard, Diego

    2012-01-01

    Data-driven methodologies have recently emerged as an important paradigm alternative to model-based controller design and several such methodologies are formulated as an H2 performance optimization. This book presents a comprehensive theoretical treatment of the H2 approach to data-driven control design. The fundamental properties implied by the H2 problem formulation are analyzed in detail, so that common features to all solutions are identified. Direct methods (VRFT) and iterative methods (IFT, DFT, CbT) are put under a common theoretical framework. The choice of the reference model, the experimental conditions, the optimization method to be used, and several other designer’s choices are crucial to the quality of the final outcome, and firm guidelines for all these choices are derived from the theoretical analysis presented. The practical application of the concepts in the book is illustrated with a large number of practical designs performed for different classes of processes: thermal, fluid processing a...

  2. Intense Visible Luminescence in CdSe Quantum Dots by Efficiency Surface Passivation with H2O Molecules

    Directory of Open Access Journals (Sweden)

    Hyeoung Woo Park

    2012-01-01

    Full Text Available We have investigated the effect of water (H2O cooling and heat treatment on the luminescence efficiency of core CdSe quantum dots (QDs. The photoluminescence (PL quantum yield of the CdSe QDs was enhanced up to ~85%, and some periodic bright points were observed in wide color ranges during the heat treatment of QDs mixed with H2O. The PL enhancement of QDs could be attributed to the recovery of QDs surface traps by unreacted ligands confined within the hydrophilic H2O molecule containers.

  3. Phase Diagram of Quaternary System NaBr-KBr-CaBr2-H2O at 323 K

    Science.gov (United States)

    Cui, Rui-Zhi; Wang, Wei; Yang, Lei; Sang, Shi-Hua

    2018-03-01

    The phase equilibria in the system NaBr-KBr-CaBr2-H2O at 323 K were studied using the isothermal dissolution equilibrium method. Using the experimental solubilities of salts data, phase diagram was constructed. The phase diagram have two invariant points, five univariant curves, and four crystallization fields. The equilibrium solid phases in the system are NaBr, NaBr · 2H2O, KBr, and CaBr2 · 4H2O. The solubilities of salts in the system at 323 K were calculated by Pitzer's equation. There is shown that the calculated solubilities agree well with experimental data.

  4. THE EFFECT OF H2O ON ICE PHOTOCHEMISTRY

    International Nuclear Information System (INIS)

    Oeberg, Karin I.; Van Dishoeck, Ewine F.; Linnartz, Harold; Andersson, Stefan

    2010-01-01

    UV irradiation of simple ices is proposed to efficiently produce complex organic species during star formation and planet formation. Through a series of laboratory experiments, we investigate the effects of the H 2 O concentration, the dominant ice constituent in space, on the photochemistry of more volatile species, especially CH 4 , in ice mixtures. In the experiments, thin (∼40 ML) ice mixtures, kept at 20-60 K, are irradiated under ultra-high vacuum conditions with a broadband UV hydrogen discharge lamp. Photodestruction cross sections of volatile species (CH 4 and NH 3 ) and production efficiencies of new species (C 2 H 6 , C 2 H 4 , CO, H 2 CO, CH 3 OH, CH 3 CHO, and CH 3 CH 2 OH) in water-containing ice mixtures are determined using reflection-absorption infrared spectroscopy during irradiation and during a subsequent slow warm-up. The four major effects of increasing the H 2 O concentration are: (1) an increase of the destruction efficiency of the volatile mixture constituent by up to an order of magnitude due to a reduction of back reactions following photodissociation, (2) a shift to products rich in oxygen, e.g., CH 3 OH and H 2 CO, (3) trapping of up to a factor of 5 more of the formed radicals in the ice, and (4) a disproportional increase in the diffusion barrier for the OH radical compared with the CH 3 and HCO radicals. The radical diffusion temperature dependencies are consistent with calculated H 2 O-radical bond strengths. All the listed effects are potentially important for the production of complex organics in H 2 O-rich icy grain mantles around protostars and should thus be taken into account when modeling ice chemistry.

  5. Ion H2+ can dissociate in a strong magnetic field

    International Nuclear Information System (INIS)

    Turbiner, A.V.; Lopez, J.C.; Flores-Riveros, A.

    2001-01-01

    In framework of a variational method the molecular ion H 2 + in a magnetic field is studied. An optimal form of the vector potential corresponding to a given magnetic field is chosen. It is shown that for any magnetic field strength as well as for any orientation of the molecular axis the system (ppe) possesses a minimum in the potential energy. The stable configuration always corresponds to elongation along the magnetic line. However, for magnetic fields B ≥ 5 x 10 11 G and some orientations the ion H 2 + becomes instable decaying to H-atom + p [ru

  6. Clinical Applications of CO2 and H2 Breath Test

    Directory of Open Access Journals (Sweden)

    ZHAO Si-qian;CHEN Bao-jun;LUO Zhi-fu

    2016-08-01

    Full Text Available Breath test is non-invasive, high sensitivity and high specificity. In this article, CO2 breath test, H2 breath test and their clinical applications were elaborated. The main applications of CO2 breath test include helicobacter pylori test, liver function detection, gastric emptying test, insulin resistance test, pancreatic exocrine secretion test, etc. H2 breath test can be applied in the diagnosis of lactose malabsorption and detecting small intestinal bacterial overgrowth. With further research, the breath test is expected to be applied in more diseases diagnosis.

  7. Backward Stochastic H2/H∞ Control: Infinite Horizon Case

    Directory of Open Access Journals (Sweden)

    Zhen Wu

    2014-01-01

    Full Text Available The mixed H2/H∞ control problem is studied for systems governed by infinite horizon backward stochastic differential equations (BSDEs with exogenous disturbance signal. A necessary and sufficient condition for the existence of a unique solution to the H2/H∞ control problem is derived. The equivalent feedback solution is also discussed. Contrary to deterministic or stochastic forward case, the feedback solution is no longer feedback of the current state; rather, it is feedback of the entire history of the state.

  8. NASA Lewis H2-O2 MHD program

    Science.gov (United States)

    Smith, M.; Nichols, L. D.; Seikel, G. R.

    1974-01-01

    Performance and power costs of H2-O2 combustion powered steam-MHD central power systems are estimated. Hydrogen gas is assumed to be transmitted by pipe from a remote coal gasifier into the city and converted to electricity in a steam MHD plant having an integral gaseous oxygen plant. These steam MHD systems appear to offer an attractive alternative to both in-city clean fueled conventional steam power plants and to remote coal fired power plants with underground electric transmission into the city. Status and plans are outlined for an experimental evaluation of H2-O2 combustion-driven MHD power generators at NASA Lewis Research Center.

  9. Explaining the symmetry breaking observed in the endofullerenes H2@C60, HF@C60, and H2O@C60.

    Science.gov (United States)

    Felker, Peter M; Vlček, Vojtěch; Hietanen, Isaac; FitzGerald, Stephen; Neuhauser, Daniel; Bačić, Zlatko

    2017-11-29

    Symmetry breaking has been recently observed in the endofullerenes M@C 60 (M = H 2 , HF, H 2 O), manifesting in the splittings of the three-fold degenerate ground states of the endohedral ortho-H 2 , ortho-H 2 O and the j = 1 level of HF. The nature of the interaction causing the symmetry breaking is established in this study. A fragment of the solid C 60 is considered, comprised of the central C 60 molecule surrounded by twelve nearest-neighbor (NN) C 60 molecules. The fullerenes have either P (major) or H (minor) orientational orderings, and are assumed to be rigid with I h symmetry. Only the central C 60 is occupied by the guest molecule M, while the NN fullerenes are all empty. The key proposition of the study is that the electrostatic interactions between the charge densities on the NN C 60 molecules and that on M inside the central C 60 give rise to the symmetry breaking responsible for the measured level splittings. Using this model, the M@C 60 level splittings of interest are calculated variationally and using perturbation theory, for both the P and H orientations. Those obtained for the dominant P orientation are in excellent agreement with the experimental results, with respect to the splitting magnitudes and patterns, for all three M@C 60 systems considered, pointing strongly to the quadrupolar M-NN interactions as the main cause of the symmetry breaking. The level splittings calculated for the H orientation are about 30 times smaller than the ones in the P orientation.

  10. Adsorption of CO, CO2, H2, and H2O on titania surfaces with different oxidation states

    International Nuclear Information System (INIS)

    Raupp, G.B.; Dumesic, J.A.

    1985-01-01

    The adsorptive properties of titania surfaces with different oxidation states were proved by temperature-programmed desorption (TPD) of CO, H 2 , CO 2 , and H 2 O. Auger electron spectroscopy and X-ray photoelectron spectroscopy revealed that vacuum annealing an oxidized titanium foil at temperatures from 300 to 800 K was an effective means of systematically varying the average surface oxidation state from Ti 4+ to Ti 2+ . Carbon monoxide weakly adsorbed (desorption energy of 44-49 kJ x mol -1 ) in a carbonyl fashion on coordinatively unsaturated cation sites. Titania surfaces were inert with respect to H 2 adsorption and dissociation. Carbon dioxide adsorbed in a linear molecular fashion. Water adsorbed both molecularly and dissociatively. Results are discussed in terms of the role of titania oxidation state in CO hydrogenation over titania-supported metal catalysts. 74 references, 7 figures

  11. Review of H2 and O2 detection in LWRS

    International Nuclear Information System (INIS)

    Neidel, E.C.; Castle, J.G. Jr.

    1981-01-01

    Hydrogen detection systems are being installed in existing LWR's and are being planned for new ones. This review summarizes the present status of instrument availability and of application in nuclear power plants. The H 2 sensors in most of the detection systems purchased to date by the nuclear utilities are being located outside of containment. The air sampled for each H 2 sensor is circulated outside to the analyzer and back through two pipes which penetrate the containment wall. The travel time for the air to reach the sensor increases the response time for H 2 detection by approximately one-half minute. A few of the utilities will operate their H 2 sensors inside LWR containment. Since these systems lack radiation-hardened electronics, they require multiple wire penetrations which considerably increase installation costs and reduce the attractiveness of these systems. One electric power utility has requested quotations from hydrogen detector manufacturers for hydrogen detection equipment with better performance and faster system response than that presently available commercially. The requested detector response time of 15 seconds or less would permit the decision delay prior to initiating hydrogen control measures to be on the order of one minute

  12. DFT Calculation of IR Absorption Spectra for PCE-nH2O, TCE-nH2O, DCE-nH2O, VC-nH2O for Small and Water-Dominated Molecular Clusters

    Science.gov (United States)

    2017-10-31

    these clusters is important for understanding the scattering and absorption of radiation transmitted through ambient environments, which is for...associated with different types of ambient molecules, e.g., H2O, in order to apply background subtraction or spectral-signature-correlation algorithms

  13. Dynamics of H2 on Ti/Al(100) surfaces

    NARCIS (Netherlands)

    Chen, Jian-Cheng

    2011-01-01

    What is the catalytic role played by titanium in the hydrogen storage material NaAlH4? This thesis aims at unraveling the dynamics of an elementary reaction: H2 dissociation on Ti/Al(100) surfaces. Although this reaction is not the rate limiting step in the hydrogen storage of NaAlH4, it is an

  14. Generalized H2 Control Synthesis for Periodic Systems

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Stoustrup, Jakob

    2001-01-01

    A control synthesis of periodic processes is addressed in this paper. A class of linear discrete time periodic systems with performance specified by the generalized $H_2$ operator norm, is considered. The paper proposes an LMI solution to this problem, the sufficient and necessary conditions for ...

  15. H2S-Mediated Thermal and Photochemical Methane Activation

    NARCIS (Netherlands)

    Baltrusaitis, Jonas; de Graaf, Coen; Broer, Ria; Patterson, Eric V.

    2013-01-01

    Sustainable, low-temperature methods for natural gas activation are critical in addressing current and foreseeable energy and hydrocarbon feedstock needs. Large portions of natural gas resources are still too expensive to process due to their high content of hydrogen sulfide gas (H2S) mixed with

  16. submitter Thermodynamics of the formation of sulfuric acid dimers in the binary (H2SO4–H2O) and ternary (H2SO4–H2O–NH3) system

    CERN Document Server

    Kürten, A; Rondo, L; Bianchi, F; Duplissy, J; Jokinen, T; Junninen, H; Sarnela, N; Schobesberger, S; Simon, M; Sipilä, M; Almeida, J; Amorim, A; Dommen, J; Donahue, N M; Dunne, E M; Flagan, R C; Franchin, A; Kirkby, J; Kupc, A; Makhmutov, V; Petäjä, T; Praplan, A P; Riccobono, F; Steiner, G; Tomé, A; Tsagkogeorgas, G; Wagner, P E; Wimmer, D; Baltensperger, U; Kulmala, M; Worsnop, D R; Curtius, J

    2015-01-01

    Sulfuric acid is an important gas influencing atmospheric new particle formation (NPF). Both the binary $(H_2SO_4–H_2O)$ system and the ternary system involving ammonia $(H_2SO_4–H_2O–NH_3)$ may be important in the free troposphere. An essential step in the nucleation of aerosol particles from gas-phase precursors is the formation of a dimer, so an understanding of the thermodynamics of dimer formation over a wide range of atmospheric conditions is essential to describe NPF. We have used the CLOUD chamber to conduct nucleation experiments for these systems at temperatures from 208 to 248 K. Neutral monomer and dimer concentrations of sulfuric acid were measured using a chemical ionization mass spectrometer (CIMS). From these measurements, dimer evaporation rates in the binary system were derived for temperatures of 208 and 223 K. We compare these results to literature data from a previous study that was conducted at higher temperatures but is in good agreement with the present study. For the ternary sys...

  17. Hot hydrogen atom reactions moderated by H2 and He

    Science.gov (United States)

    Aronowitz, S.; Scattergood, T.; Flores, J.; Chang, S.

    1986-01-01

    Photolysis experiments were performed on the H2-CD4-NH3 and He-CD4-NH3 systems. The photolysis (1849 A) involved only NH3. Mixtures of H2:CD4:NH3 included all combinations of the ratios (200,400,800):(10,20,40):4. Two He:CD4:NH3 mixtures were examined where the ratios equalled the combinations 100:(10,20):4. Abstraction of a D from CD4 by the photolytically produced hot hydrogen from ammonia was monitored by mass spectrometric determination of HD. Both experiment and semiempirical hot-atom theory show that H2 is a very poor thermalizer of hot hydrogens with excess kinetic energy of about 2 eV. Applications of the hard-sphere collision model to the H2-CD4-NH3 system resulted in predicted ratios of net HD production to NH3 decomposition that were two orders of magnitude smaller than the experimental ratios. On the other hand, helium is found to be a very efficient thermalizer; here, the classical model yields reasonable agreement with experiments. Application of a semiempirical hot-atom program gave quantitative agreement with experiment for either system.

  18. H2A Production Model, Version 2 User Guide

    Energy Technology Data Exchange (ETDEWEB)

    Steward, D.; Ramsden, T.; Zuboy, J.

    2008-09-01

    The H2A Production Model analyzes the technical and economic aspects of central and forecourt hydrogen production technologies. Using a standard discounted cash flow rate of return methodology, it determines the minimum hydrogen selling price, including a specified after-tax internal rate of return from the production technology. Users have the option of accepting default technology input values--such as capital costs, operating costs, and capacity factor--from established H2A production technology cases or entering custom values. Users can also modify the model's financial inputs. This new version of the H2A Production Model features enhanced usability and functionality. Input fields are consolidated and simplified. New capabilities include performing sensitivity analyses and scaling analyses to various plant sizes. This User Guide helps users already familiar with the basic tenets of H2A hydrogen production cost analysis get started using the new version of the model. It introduces the basic elements of the model then describes the function and use of each of its worksheets.

  19. Economic analysis of novel synergistic biofuel (H2Bioil) processes

    International Nuclear Information System (INIS)

    Singh, Navneet R.; Mallapragada, Dharik S.; Agrawal, Rakesh; Tyner, Wallace E.

    2012-01-01

    Fast-pyrolysis based processes can be built on small-scale and have higher process carbon and energy efficiency as compared to other options. H 2 Bioil is a novel process based on biomass fast-hydropyrolysis and subsequent hydrodeoxygenation (HDO) and can potentially provide high yields of high energy density liquid fuel at relatively low hydrogen consumption. This paper contains a comprehensive financial analysis of the H 2 Bioil process with hydrogen derived from different sources. Three different carbon tax scenarios are analyzed: no carbon tax, $55/metric ton carbon tax and $110/metric ton carbon tax. The break-even crude oil price for a delivered biomass cost of $94/metric ton when hydrogen is derived from coal, natural gas or nuclear energy ranges from $103 to $116/bbl for no carbon tax and even lower ($99-$111/bbl) for the carbon tax scenarios. This break-even crude oil price compares favorably with the literature estimated prices of fuels from alternate biochemical and thermochemical routes. The impact of the chosen carbon tax is found to be limited relative to the impact of the H 2 source on the H 2 Bioil break-even price. The economic robustness of the processes for hydrogen derived from coal, natural gas, or nuclear energy is seen by an estimated break-even crude oil price of $114-$126/bbl when biomass cost is increased to $121/metric ton. (orig.)

  20. Analytical potential energy function for the Br + H2 system

    International Nuclear Information System (INIS)

    Kurosaki, Yuzuru

    2001-01-01

    Analytical functions with a many-body expansion for the ground and first-excited-state potential energy surfaces for the Br+H 2 system are newly presented in this work. These functions describe the abstraction and exchange reactions qualitatively well, although it has been found that the function for the ground-state potential surface is still quantitatively unsatisfactory. (author)

  1. Inelastic scattering in metal-H-2-metal junctions

    DEFF Research Database (Denmark)

    Kristensen, I. S.; Paulsson, Magnus; Thygesen, Kristian Sommer

    2009-01-01

    We present first-principles calculations of the dI/dV characteristics of an H-2 molecule sandwiched between Au and Pt electrodes in the presence of electron-phonon interactions. The conductance is found to decrease by a few percentages at threshold voltages corresponding to the excitation energy ...

  2. Energy loss of fast H2+ molecules in solids

    International Nuclear Information System (INIS)

    Steinbeck, J.; Dettmann, K.

    1978-01-01

    The electronic energy loss of fast H 2 + ions in thin solids is investigated. The energy loss is influenced by the correlated propagation of the protons which act coherently on the target electrons through a pure Coulomb potential. This influence increases with increasing velocity and decreasing target thickness. The model proposed does not involve the so called 'wake potential'. (author)

  3. H2O masers - survey of the galactic plane - I

    International Nuclear Information System (INIS)

    Scalise Junior, E.; Braz, M.A.

    A search for 22 GHz water vapor emission in continum HII regions peaks, and in Type I OH sources has been conducted at the Itapetinga Radio Observatory Sao Paulo, Brazil. 14 new sources displaying H 2 O maser emission were found [pt

  4. Intermolecular Interactions in Ternary Glycerol–Sample–H2O

    DEFF Research Database (Denmark)

    Westh, Peter; Rasmussen, Erik Lumby; Koga, Yoshikata

    2011-01-01

    We studied the intermolecular interactions in ternary glycerol (Gly)–sample (S)–H2O systems at 25 °C. By measuring the excess partial molar enthalpy of Gly, HGlyEHEGly, we evaluated the Gly–Gly enthalpic interaction, HGly-GlyEHEGly--Gly, in the presence of various samples (S). For S, tert...

  5. Reaction of ferric leghemoglobin with H2O2

    DEFF Research Database (Denmark)

    Moreau, S; Davies, M J; Puppo, A

    1995-01-01

    Ferric leghemoglobin in the presence of H2O2 is known to give rise to protein radicals, at least one of which is centred on a tyrosine residue. These radicals are quenched by at least two processes. The first one involves an intramolecular heme-protein cross-link probably involving the tyrosine...

  6. Triazine chemistry: removing H2S and mercaptans

    Energy Technology Data Exchange (ETDEWEB)

    Owens, Thomas R.; Lesage, Kevin L.; Clark, Peter D.; Primak, Alex [University of Calgary (Canada)

    2011-07-01

    Chemical scavengers like triazines cause sulfur to be deposited with by-products and not in its pure form. This paper presents techniques to remove H2S and mercaptans. One process for H2S scavenging is injection of formaldehyde into the pipelines. But this causes solids to be formed as by-products. Triazine chemistry and synthesis and reaction mechanisms for H2S and its by-products that are formed are shown. Some of the mitigation strategies include maintaining optimal methanol concentration and running the chemical at lower scavenging efficiencies. There are no documented issues regarding the reaction of triazines with mercaptans. The experimental setup and process are explained and the results show that scavenging efficiency for mercaptans is inversely related to its molecular weight. Improved scavenging systems and various methods for mercaptan scavenging are given. From the study it can be concluded that triazine-based scavengers efficiently remove low levels of H2S from gas streams but not mercaptans.

  7. Solar kerosene from H2O and CO2

    Science.gov (United States)

    Furler, P.; Marxer, D.; Scheffe, J.; Reinalda, D.; Geerlings, H.; Falter, C.; Batteiger, V.; Sizmann, A.; Steinfeld, A.

    2017-06-01

    The entire production chain for renewable kerosene obtained directly from sunlight, H2O, and CO2 is experimentally demonstrated. The key component of the production process is a high-temperature solar reactor containing a reticulated porous ceramic (RPC) structure made of ceria, which enables the splitting of H2O and CO2 via a 2-step thermochemical redox cycle. In the 1st reduction step, ceria is endo-thermally reduced using concentrated solar radiation as the energy source of process heat. In the 2nd oxidation step, nonstoichiometric ceria reacts with H2O and CO2 to form H2 and CO - syngas - which is finally converted into kerosene by the Fischer-Tropsch process. The RPC featured dual-scale porosity for enhanced heat and mass transfer: mm-size pores for volumetric radiation absorption during the reduction step and μm-size pores within its struts for fast kinetics during the oxidation step. We report on the engineering design of the solar reactor and the experimental demonstration of over 290 consecutive redox cycles for producing high-quality syngas suitable for the processing of liquid hydrocarbon fuels.

  8. Glitters of warm H2 in cold diffuse molecular gas

    NARCIS (Netherlands)

    Falgarone, Edith; Beichman, Chaz; Boulanger, Francois; Combes, Francoise; Gry, Cecile; Helou, Georges; Laureijs, Rene; Pineau Des Forets, Guillaume; Valentijn, Edwin; Verstraete, Laurent

    2004-01-01

    Cold molecular hydrogen, a possibly dominant gas fraction in galaxies, does not radiate due to the symmetry and small moment of inertia of the molecule. The only tracers of cold H2, the rotational lines of CO and dust thermal emission operate only in metal-rich environments. By detecting the lowest

  9. Searching for the physiological role of glucose-dependent insulinotropic polypeptide

    DEFF Research Database (Denmark)

    Holst, Jens Juul; Windeløv, Johanne Agerlin; Boer, Geke Aline

    2016-01-01

    Glucose-dependent insulinotropic polypeptide (GIP) was established as a gut hormone more than 40 years ago, and there is good experimental support for its role as an incretin hormone although deletion of the GIP receptor or the GIP cells or GIP receptor mutations have only minor effects on glucose...... in rodent point to effects on bone metabolism. Recent studies revealed pronounced inhibitory effects of GIP on bone resorption markers in humans and suggest that GIP may be (one of the) gastrointestinal regulators of bone turn-over. In support of this, a loss-of-function GIP receptor mutation in humans...

  10. Overtone vibrational spectroscopy in H2-H2O complexes: a combined high level theoretical ab initio, dynamical and experimental study.

    Science.gov (United States)

    Ziemkiewicz, Michael P; Pluetzer, Christian; Nesbitt, David J; Scribano, Yohann; Faure, Alexandre; van der Avoird, Ad

    2012-08-28

    First results are reported on overtone (v(OH) = 2 ← 0) spectroscopy of weakly bound H(2)-H(2)O complexes in a slit supersonic jet, based on a novel combination of (i) vibrationally mediated predissociation of H(2)-H(2)O, followed by (ii) UV photodissociation of the resulting H(2)O, and (iii) UV laser induced fluorescence on the nascent OH radical. In addition, intermolecular dynamical calculations are performed in full 5D on the recent ab initio intermolecular potential of Valiron et al. [J. Chem. Phys. 129, 134306 (2008)] in order to further elucidate the identity of the infrared transitions detected. Excellent agreement is achieved between experimental and theoretical spectral predictions for the most strongly bound van der Waals complex consisting of ortho (I = 1) H(2) and ortho (I = 1) H(2)O (oH(2)-oH(2)O). Specifically, two distinct bands are seen in the oH(2)-oH(2)O spectrum, corresponding to internal rotor states in the upper vibrational manifold of Σ and Π rotational character. However, none of the three other possible nuclear spin modifications (pH(2)-oH(2)O, pH(2)-pH(2)O, or oH(2)-pH(2)O) are observed above current signal to noise level, which for the pH(2) complexes is argued to arise from displacement by oH(2) in the expansion mixture to preferentially form the more strongly bound species. Direct measurement of oH(2)-oH(2)O vibrational predissociation in the time domain reveals lifetimes of 15(2) ns and <5(2) ns for the Σ and Π states, respectively. Theoretical calculations permit the results to be interpreted in terms of near resonant energy levels and intermolecular alignment of the H(2) and H(2)O wavefunctions, providing insight into predissociation dynamical pathways from these metastable levels.

  11. Mechanistic Insights into the H2S-Mediated Reduction of Aryl Azides Commonly Used in H2S Detection

    Science.gov (United States)

    Henthorn, Hillary A.; Pluth, Michael D.

    2016-01-01

    Hydrogen sulfide (H2S) is an important biological mediator and has been at the center of a rapidly expanding field focused on understanding the biogenesis and action of H2S as well as other sulfur-related species. Concomitant with this expansion has been the development of new chemical tools for H2S research. The use of H2S-selective fluorescent probes that function by H2S-mediated reduction of fluorogenic aryl azides has emerged as one of the most common methods for H2S detection. Despite this prevalence, the mechanism of this important reaction remains under-scrutinized. Here we present a combined experimental and computational investigation of this mechanism. We establish that HS–, rather than diprotic H2S, is the active species required for aryl azide reduction. The hydrosulfide anion functions as a one-electron reductant, resulting in the formation of polysulfide anions, such as HS2–, which were confirmed and trapped as organic polysulfides by benzyl chloride. The overall reaction is first-order in both azide and HS– under the investigated experimental conditions with ΔS‡ = –14(2) eu and ΔH‡ = 13.8(5) kcal/mol in buffered aqueous solution. By using NBu4SH as the sulfide source, we were able to observe a reaction intermediate (λmax = 473 nm), which we attribute to formation of an anionic azidothiol intermediate. Our mechanistic investigations support that this intermediate is attacked by HS– in the rate-limiting step of the reduction reaction. Complementing our experimental mechanistic investigations, we also performed DFT calculations at the B3LYP/6-31G(d,p), B3LYP/6-311++G(d,p), M06/TZVP, and M06/def2-TZVPD levels of theory applying the IEF-PCM water and MeCN solvation models, all of which support the experimentally determined reaction mechanism and provide cohesive mechanistic insights into H2S-mediated aryl azide reduction. PMID:26540330

  12. Computational study on the mechanisms and energetics of trimethylindium reactions with H2O and H2S.

    Science.gov (United States)

    Raghunath, P; Lin, M C

    2007-07-19

    The reactions of trimethylindium (TMIn) with H2O and H2S are relevant to the chemical vapor deposition of indium oxide and indium sulfide thin films. The mechanisms and energetics of these reactions in the gas phase have been investigated by density functional theory and ab initio calculations using the CCSD(T)/[6-31G(d,p)+Lanl2dz]//B3LYP/[6-31G(d,p)+Lanl2dz] and CCSD(T)/[6-31G(d,p)+Lanl2dz] //MP2/[6-31G(d,p)+Lanl2dz] methods. The results of both methods are in good agreement for the optimized geometries and relative energies. When TMIn reacts with H2O and H2S, initial molecular complexes [(CH3)3In:OH2 (R1)] and [(CH3)3In:SH2 (R2)] are formed with 12.6 and 3.9 kcal/mol binding energies. Elimination of a CH4 molecule from each complex occurs with a similar energy barrier at TS1 (19.9 kcal/mol) and at TS3 (22.1 kcal/mol), respectively, giving stable intermediates (CH3)2InOH and (CH3)2InSH. The elimination of the second CH4 molecule from these intermediate products, however, has to overcome very high and much different barriers of 66.1 and 53.2 kcal/mol, respectively. In the case of DMIn with H2O and H2S reactions, formation of both InO and InS is exothermic by 3.1 and 30.8 kcal/mol respectively. On the basis of the predicted heats of formation of R1 and R2 at 0 K and -20.1 and 43.6 kcal/mol, the heats of formation of (CH3)2InOH, (CH3)2InSH, CH3InO, CH3InS, InO, and InS are estimated to be -20.6, 31.8, and 29.0 and 48.4, 35.5, and 58.5 kcal/mol, respectively. The values for InO and InS are in good agreement with available experimental data. A similar study on the reactions of (CH3)2In with H2O and H2S has been carried out; in these reactions CH3InOH and CH3InSH were found to be the key intermediate products.

  13. Muon spin relaxation study of Zr(H2PO4)(PO4).2H2O.

    Science.gov (United States)

    Clayden, Nigel J; Cottrell, Stephen P

    2006-07-14

    Muon spin relaxation has been used to study the muon dynamics in the layered zirconium phosphate Zr(H(2)PO(4))(PO(4)).2H(2)O as a function of temperature. Radiofrequency decoupling was used to establish the origin of the local dipolar field as coupling with (1)H spins. Muons were trapped at two sites, one identified as HMuO and the other consistent with PO-Mu on the basis of their zero-field second moments. Although a small decrease in the local nuclear dipolar field was seen with temperature, the muons remained essentially static over the temperature range 20-300 K.

  14. Histone H2AFX Links Meiotic Chromosome Asynapsis to Prophase I Oocyte Loss in Mammals.

    Directory of Open Access Journals (Sweden)

    Jeffrey M Cloutier

    2015-10-01

    Full Text Available Chromosome abnormalities are common in the human population, causing germ cell loss at meiotic prophase I and infertility. The mechanisms driving this loss are unknown, but persistent meiotic DNA damage and asynapsis may be triggers. Here we investigate the contribution of these lesions to oocyte elimination in mice with chromosome abnormalities, e.g. Turner syndrome (XO and translocations. We show that asynapsed chromosomes trigger oocyte elimination at diplonema, which is linked to the presence of phosphorylated H2AFX (γH2AFX. We find that DNA double-strand break (DSB foci disappear on asynapsed chromosomes during pachynema, excluding persistent DNA damage as a likely cause, and demonstrating the existence in mammalian oocytes of a repair pathway for asynapsis-associated DNA DSBs. Importantly, deletion or point mutation of H2afx restores oocyte numbers in XO females to wild type (XX levels. Unexpectedly, we find that asynapsed supernumerary chromosomes do not elicit prophase I loss, despite being enriched for γH2AFX and other checkpoint proteins. These results suggest that oocyte loss cannot be explained simply by asynapsis checkpoint models, but is related to the gene content of asynapsed chromosomes. A similar mechanistic basis for oocyte loss may operate in humans with chromosome abnormalities.

  15. Advanced NaBH4/H2O2 Fuel Cell for Space Applications

    Science.gov (United States)

    Miley, George H.; Kim, Kyu-Jung; Luo, Nie; Shrestha, Prajakti Joshi

    2009-03-01

    Fuel cells have played an important role in NASA's space program starting with the Gemini space program. However, improved fuel cell performance will be needed to enable demanding future missions. An advanced fuel cell (FC) using liquid fuel and oxidizer is being developed by U of IL/NPL team to provide air independence and to achieve higher power densities than normal H2/O2 fuel cells (Lou et al., 2008; Miley, 2007). Hydrogen peroxide (H2O2) is used in this FC directly at the cathode (Lou and Miley, 2004). Either of two types of reactant, namely a gas-phase hydrogen or an aqueous NaBH4 solution, is utilized as fuel at the anode. Experiments with both 10-W single cells and 500-W stacks demonstrate that the direct utilization of H2O2 and NaBH4 at the electrodes result in >30% higher voltage output compared to the ordinary H2/O2 FC (Miley, 2007). Further, the use of this combination of all liquid fuels provides—from an operational point of view—significant advantages (ease of storage, reduced pumping requirements, simplified heat removal). This design is inherently compact compared to other fuel cells that use gas phase reactants. This results in a high overall system (including fuel tanks, pumps and piping, waste heat radiator) power density. Further, work is in progress on a regenerative version which uses an electrical input, e.g. from power lines or a solar panel to regenerate reactants.

  16. Tricyclic sesquiterpene copaene prevents H2O2-induced neurotoxicity

    Directory of Open Access Journals (Sweden)

    Hasan Turkez

    2014-02-01

    Full Text Available Aim: Copaene (COP, a tricyclic sesquiterpene, is present in several essential oils of medicinal and aromatic plants and has antioxidant and anticarcinogenic features. But, very little information is known about the effects of COP on oxidative stress induced neurotoxicity. Method: We used hydrogen peroxide (H2O2 exposure for 6 h to model oxidative stress. Therefore, this experimental design allowed us to explore the neuroprotective potential of COP in H2O2-induced toxicity in rat cerebral cortex cell cultures for the first time. For this purpose, methyl thiazolyl tetrazolium (MTT and lactate dehydrogenase (LDH release assays were carried out to evaluate cytotoxicity. Total antioxidant capacity (TAC and total oxidative stress (TOS parameters were used to evaluate oxidative changes. In addition to determining of 8-hydroxy-2-deoxyguanosine (8-OH-dG levels, the single cell gel electrophoresis (SCGE or comet assay was also performed for measuring the resistance of neuronal DNA to H2O2-induced challenge. Result: The results of this study showed that survival and TAC levels of the cells decreased, while TOS, 8-OH-dG levels and the mean values of the total scores of cells showing DNA damage increased in the H2O2 alone treated cultures. But pre-treatment of COP suppressed the cytotoxicity, genotoxicity and oxidative stress which were increased by H2O2. Conclusion: It is proposed that COP as a natural product with an antioxidant capacity in mitigating oxidative injuries in the field of neurodegenerative diseases. [J Intercult Ethnopharmacol 2014; 3(1.000: 21-28

  17. H2 emission from non-stationary magnetized bow shocks

    Science.gov (United States)

    Tram, L. N.; Lesaffre, P.; Cabrit, S.; Gusdorf, A.; Nhung, P. T.

    2018-01-01

    When a fast moving star or a protostellar jet hits an interstellar cloud, the surrounding gas gets heated and illuminated: a bow shock is born that delineates the wake of the impact. In such a process, the new molecules that are formed and excited in the gas phase become accessible to observations. In this paper, we revisit models of H2 emission in these bow shocks. We approximate the bow shock by a statistical distribution of planar shocks computed with a magnetized shock model. We improve on previous works by considering arbitrary bow shapes, a finite irradiation field and by including the age effect of non-stationary C-type shocks on the excitation diagram and line profiles of H2. We also examine the dependence of the line profiles on the shock velocity and on the viewing angle: we suggest that spectrally resolved observations may greatly help to probe the dynamics inside the bow shock. For reasonable bow shapes, our analysis shows that low-velocity shocks largely contribute to H2 excitation diagram. This can result in an observational bias towards low velocities when planar shocks are used to interpret H2 emission from an unresolved bow. We also report a large magnetization bias when the velocity of the planar model is set independently. Our 3D models reproduce excitation diagrams in BHR 71 and Orion bow shocks better than previous 1D models. Our 3D model is also able to reproduce the shape and width of the broad H2 1-0S(1) line profile in an Orion bow shock (Brand et al. 1989).

  18. Improved radiosensitive microcapsules using H2O2

    International Nuclear Information System (INIS)

    Harada, Satoshi; Ehara, Shigeru; Ishii, Keizo

    2010-01-01

    The radiation-induced releasing of the liquid-core of the microcapsules was improved using H 2 O 2 , which produced O 2 generation of H 2 O 2 after irradiation. Further, we tested whether these microcapsules enhanced the antitumor effects and decreased the adverse effects in vivo in C3He/J mice. The capsules were produced by spraying a mixture of 3.0% hyaluronic acid, 2.0% alginate, 3.0% H 2 O 2 , and 0.3 mmol of carboplatin on a mixture of 0.3 mol FeCl 2 and 0.15 mol CaCl 2 . The microcapsules were subcutaneously injected into MM46 tumors that had been inoculated in the left hind legs of C3He/J mice. The radiotherapy comprised tumor irradiation with 10 Gy or 20 Gy 60 Co. The antitumor effect of the microcapsules was tested by measuring tumor size and monitoring tumor growth. Three types of adverse effects were considered: fuzzy hair, loss of body weight, and death. The size of the capsule size was 23±2.4 μmφ and that of the liquid core, 20.2±2.2 μmφ. The injected microcapsules localized drugs around the tumor. The production of O 2 by radiation increased the release of carboplatin from the microcapsules. The antitumor effects of radiation, carboplatin, and released oxygen were synergistic. Localization of the carboplatin decreased its adverse effects. However, the H 2 O 2 caused ulceration of the skin in the treated area. The use of our microcapsules enhanced the antitumor effects and decreased the adverse effects of carboplatin. However, the skin-ulceration caused by H 2 O 2 must be considered before these microcapsules can be used clinically. (author)

  19. Study of Phase Equilibrium of NaBr + KBr + H2O and NaBr + MgBr2 + H2O at 313.15 K

    Directory of Open Access Journals (Sweden)

    Qing Chen

    2017-01-01

    Full Text Available The phase equilibrium for the ternary systems NaBr + KBr + H2O and NaBr + MgBr2 + H2O at 313.15 K was investigated by isothermal solution saturation method. The solubilities of salts and the densities of saturated solutions in these ternary systems were determined by chemical methods, while the equilibrium solid phases were analyzed by Schreinermarker wet residues method. Based on the experimental data, phase diagrams and density versus composition diagrams were plotted. The two ternary systems were type of simple common-saturation and without complex salt and solid solution. There are in all two crystalline regions, two univariant curves, and one invariant point in these phase diagrams of two ternary systems at 313.15 K. The equilibrium solid phases in the ternary system NaBr + KBr + H2O are KBr and NaBr·2H2O, and those in the ternary system NaBr + MgBr2 + H2O are NaBr·2H2O and MgBr2·6H2O.

  20. Tunneling Reaction Kinetics for the Hydrogen Abstraction Reaction H + H2S → H2 + HS in the Interstellar Medium.

    Science.gov (United States)

    Lamberts, Thanja; Kästner, Johannes

    2017-12-28

    The hydrogen abstraction reaction between H and H 2 S, yielding HS and H 2 as products, has been studied within the framework of interstellar surface chemistry. High-temperature rate constants below 2000 K are calculated in the gas phase and are in agreement with previously reported values. Subsequently, low-temperature rate constants down to 55 K are presented for the first time that are of interest to astrochemistry, i.e., covering both bimolecular and unimolecular reaction mechanisms. For this, a so-called implicit surface model is used. In strict terms, this is a structural gas-phase model in which the restriction of the rotation in the solid state is taken into account. The calculated kinetic isotope effects are explained in terms of the difference in activation and delocalization. All rate constants are calculated at the UCCSD(T)-F12/cc-VTZ-F12 level of theory. Finally, we show that the energetics of the reaction is affected to an only small extent by the presence of H 2 O or H 2 S molecular clusters that simulate an ice surface, calculated at the MPWB1K/def2-TZVP level of theory.

  1. Speciation in the aqueous H+/H2VO4-/H2O2/citrate system of biomedical interest.

    Science.gov (United States)

    Gorzsás, András; Getty, Kendra; Andersson, Ingegärd; Pettersson, Lage

    2004-09-21

    The speciation in the quaternary aqueous H+/H2VO4-/H2O2/citrate (Cit3-) and H+/H2VO4-/Cit3-/L-(+)-lactate (Lac-) systems has been determined at 25 degrees C in the physiological medium of 0.150 M Na(Cl). A combination of 51V NMR integral intensities and chemical shift (Bruker AMX500) as well as potentiometric data (glass electrode) have been collected and evaluated with the computer program LAKE, which is able to treat multimethod data simultaneously. The pKa-values for citric acid have been determined as 2.94, 4.34 and 5.61. Altogether six vanadate-citrate species have been found in the ternary H+/H2VO4-/Cit3- system in the pH region 2-10, only two of which are mononuclear. Reduction of vanadium(V) becomes more pronounced at pH acidic solutions limited the final model to pH > 4. In the quaternary H+/H2VO4-/Cit3-/Lac- system, two mixed-ligand species have been determined, with the compositions V2CitLac2- and V2CitLac3- (pKa = 5.0). To our knowledge, this is the first time such complexes have been reported for vanadium(V). 51V NMR chemical shifts, compositions and formation constants are given, and equilibrium conditions are illustrated in distribution diagrams as well as the fit of the model to the experimental data. When suitable, structural proposals are given, based on 13C NMR measurements and available literature data of related compounds.

  2. Differential Microbicidal Effects of Human Histone Proteins H2A and H2B on Leishmania Promastigotes and Amastigotes▿

    Science.gov (United States)

    Wang, Yingwei; Chen, Yang; Xin, Lijun; Beverley, Stephen M.; Carlsen, Eric D.; Popov, Vsevolod; Chang, Kwang-Poo; Wang, Ming; Soong, Lynn

    2011-01-01

    Recent studies have shown that histone proteins can act as antimicrobial peptides in host defense against extracellular bacteria, fungi, and Leishmania promastigotes. In this study, we used human recombinant histone proteins to further study their leishmaniacidal effects and the underlying mechanisms. We found that the histones H2A and H2B (but not H10) could directly and efficiently kill promastigotes of Leishmania amazonensis, L. major, L. braziliensis, and L. mexicana in a treatment dose-dependent manner. Scanning electron microscopy revealed surface disruption of histone-treated promastigotes. More importantly, the preexposure of promastigotes to histone proteins markedly decreased the infectivity of promastigotes to murine macrophages (Mφs) in vitro. However, axenic and lesion-derived amastigotes of L. amazonensis and L. mexicana were relatively resistant to histone treatment, which correlated with the low levels of intracellular H2A in treated amastigotes. To understand the mechanisms underlying these differential responses, we investigated the role of promastigote surface molecules in histone-mediated killing. Compared with the corresponding controls, transgenic L. amazonensis promastigotes expressing lower levels of surface gp63 proteins were more susceptible to histone H2A, while L. major and L. mexicana promastigotes with targeted deletion of the lipophosphoglycan 2 (lpg2) gene (but not the lpg1 gene) were more resistant to histone H2A. We discuss the influence of promastigote major surface molecules in the leishmaniacidal effect of histone proteins. This study provides new information on host innate immunity to different developmental stages of Leishmania parasites. PMID:21189319

  3. Calculation of the Isotope Cluster for Polypeptides by Probability Grouping

    Science.gov (United States)

    Olson, Matthew T.; Yergey, Alfred L.

    2014-01-01

    This paper presents a novel theoretical basis for accurately calculating the isotope cluster of polypeptides. In contrast to previous approaches to this problem, which consider exhaustive or near exhaustive combinations of isotopic species, the program, Neutron Cluster, groups probabilities to yield highly accurate information without elucidating any fine structure within a nominal mass unit. This is a fundamental difference from any previously described algorithm for calculating the isotope cluster. As a result of this difference, the accurate isotope clusters for high molecular weight polypeptides can be calculated rapidly without any pruning. When applied to isotope enriched polypeptides, the algorithm introduces “grouping error”, which is described, quantified, and avoided by using probability partitioning. PMID:19026561

  4. Separation, antitumor activities, and encapsulation of polypeptide from Chlorella pyrenoidosa.

    Science.gov (United States)

    Wang, Xiaoqin; Zhang, Xuewu

    2013-01-01

    Chlorella pyrenoidosa is a unicellular green algae and has been a popular foodstuff worldwide. However, no reports on the antitumor peptides from such a microalgae are available in the literature. In this study, using low-temperature high-pressure extraction, enzymatic hydrolysis, ion exchange, and gel filtration chromatography, we separated a polypeptide that exhibited inhibitory activity on human liver cancer HepG2 cells, and named the polypeptide CPAP (C. pyrenoidosa antitumor polypeptide). Furthermore, the micro- and nanoencapsulation of CPAP were investigated by using two methods: complex coacervation and ionotropic gelation. The in vitro release tests revealed that CPAP was well preserved against gastric enzymatic degradation after micro/nanoencapsulation and the slowly controlled release in the intestine could be potentially achieved. These results suggest that CPAP may be a useful ingredient in food, nutraceutical, and pharmaceutical applications. © 2013 American Institute of Chemical Engineers.

  5. Rotational State Effects in the Dissociative Recombination of H2+

    Science.gov (United States)

    Zhaunerchyk, V.; Al-Khalili, A.; Thomas, R. D.; Geppert, W. D.; Bednarska, V.; Petrignani, A.; Ehlerding, A.; Hamberg, M.; Larsson, M.; Rosen, S.; van der Zande, W. J.

    2007-07-01

    We have studied the dissociative recombination (DR) of molecular hydrogen ions with slow electrons over a range of collision energies from 0 to 400 meV. By employing a pulsed expansion source for rotational cooling and by exploiting superelastic collisions with near-0-eV electrons in a heavy ion storage ring for vibrational cooling, we observe a highly structured DR cross section, comparable to that reported for HD+. Using para-hydrogen-enriched ion beams, we identify for the first time features in the DR cross sections attributed to ν=0, J=even molecules (para-H2) and ν=0, J=odd (ortho-H2) molecules, separately. Indications are given that para levels have different DR rate coefficients from ortho levels for the first four vibrational levels at near-0-eV collisions.

  6. Ab initio Potential Energy Surface for H-H2

    Science.gov (United States)

    Partridge, Harry; Bauschlicher, Charles W., Jr.; Stallcop, James R.; Levin, Eugene

    1993-01-01

    Ab initio calculations employing large basis sets are performed to determine an accurate potential energy surface for H-H2 interactions for a broad range of separation distances. At large distances, the spherically averaged potential determined from the calculated energies agrees well with the corresponding results determined from dispersion coefficients; the van der Waals well depth is predicted to be 75 +/- (mu)E(sub h). Large basis sets have also been applied to reexamine the accuracy of theoretical repulsive potential energy surfaces. Multipolar expansions of the computed H-H2 potential energy surface are reported for four internuclear separation distances (1.2, 1.401, 1.449, and 1.7a(sub 0) of the hydrogen molecule. The differential elastic scattering cross section calculated from the present results is compared with the measurements from a crossed beam experiment.

  7. Ro-vibrational states of H+2. Variational calculations

    Science.gov (United States)

    Korobov, Vladimir I.

    2018-01-01

    The nonrelativistic variational calculation of a complete set of ro-vibrational states in the H$_2^+$ molecular ion supported by the ground $1s\\sigma$ adiabatic potential is presented. It includes both bound states and resonances located above the $n=1$ threshold. In the latter case we also evaluate a predissociation width of a state wherever it is significant. Relativistic and radiative corrections are discussed and effective adiabatic potentials of these corrections are included as supplementary files.

  8. H 2 guaranteed cost control of discrete linear systems

    Directory of Open Access Journals (Sweden)

    Colmenares W.

    2000-01-01

    Full Text Available This paper presents necessary and sufficient conditions for the existence of a quadratically stabilizing output feedback controller which also assures H 2 guaranteed cost performance on a discrete linear uncertain system where the uncertainty is of the norm bounded type. The conditions are presented as a collection of linear matrix inequalities.The solution, however requires a search over a scalar parameter space.

  9. Robust Schur Stability and Robust H^2 Performance

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Zhao, K.-Y.

    1996-01-01

    In this paper we address the problems of robust stability androbust QTR H^2 performance for uncertain discrete time systemswith nonlinear parametric uncertainties. We consider two families ofsystems with parametric uncertainties described by state space modelswhich offer a fairly general...... providea line search algorithm for the these two problems in case of two parameters.Both for the robust stability and the robust performance probelm, explicitnecessary and sufficient conditions are derived. An illustrative exampledemonstrates the algorithms....

  10. Thermodynamics of the CSCl-H2O system at low temperatures

    International Nuclear Information System (INIS)

    Monnin, C.; Dubois, M.

    1999-01-01

    The interpretation of fluid-inclusion data requires knowledge of phase diagrams at low (subfreezing) temperatures. From the example of the CsCl-H 2 O system, we here investigate the possibility to build such diagrams from thermodynamic models of aqueous solutions parameterized at higher temperatures. Holmes and Mesmer (1983) have built a model for the thermodynamic properties of CsCl(aq) based on Pitzer's equation fit to thermodynamic data mainly at temperatures above 0 C along with a few freezing-point-depression data down to -8 C. We show how this model can be used along with the published water-ice equilibrium constant and thermodynamic data at 25 C for Cs + (aq), Cl - (aq) and CsCl(s), to predict with confidence the ice-liquid-vapor (ILV) and the salt-liquid-vapor (SLV) curves down to the eutectic temperature for the CsCl-H 2 O system. (orig.)

  11. Product fine-structure resolved photodissociation dynamics: The A band of H2O

    International Nuclear Information System (INIS)

    Zhou, Linsen; Xie, Daiqian; Sun, Zhigang; Guo, Hua

    2014-01-01

    The photodissociation dynamics of H 2 O in its first absorption band is investigated on an accurate potential energy surface based on a large number of high-level ab initio points. Several ro-vibrational states of the parent molecule are considered. Different from most previous theoretical studies, the spin-orbit and Λ-doublet populations of the open-shell OH fragment are reported from full-dimensional wave packet calculations. The populations of the two spin-orbit manifolds are in most cases close to the statistical limit, but the Λ-doublet is dominated by the A ″ component, thanks largely to the fast in-plane dissociation of H 2 O(A ~1 A ′′ ). Comparisons with experimental data and a Franck-Condon model are generally very good, although some discrepancies exist

  12. Fast metastable hydrogen atoms from H2 molecules: twin atoms

    Directory of Open Access Journals (Sweden)

    Trimèche A.

    2015-01-01

    Full Text Available It is a difficult task to obtain “twin atoms”, i.e. pairs of massive particles such that one can perform experiments in the same fashion that is routinely done with “twin photons”. One possible route to obtain such pairs is by dissociating homonuclear diatomic molecules. We address this possibility by investigating the production of metastable H(2s atoms coming from the dissociation of cold H2 molecules produced in a Campargue nozzle beam crossing an electron beam from a high intensity pulsed electron gun. Dissociation by electron impact was chosen to avoid limitations of target molecular excited states due to selection rules. Detectors placed several centimeters away from the collision center, and aligned with respect to possible common molecular dissociation channel, analyze the neutral fragments as a function of their time-of-flight (TOF through Lyman-α detection. Evidence for the first time observed coincidence of pairs of H(2s atoms obtained this way is presented.

  13. H2 sensing properties of modified silicon nanowires

    Directory of Open Access Journals (Sweden)

    Latefa Baba Ahmed

    2015-04-01

    Full Text Available It has been found that the silicon nanowires modified with noble metals can be used to fabricate an effective H2 gas sensor in the present study. The preparation and surface modification of silicon nanowires (SiNWs were carried out by chemical methods. The morphology of the silicon nanowires unmodified and modified with nanoparticles of platinum, palladium, silver and gold was investigated using scanning electron microscopy (SEM. The chemical composition of the silicon nanowire layers was studied by secondary ion mass spectroscopy (SIMS and energy dispersive X-ray analysis (EDX. The structures of type metal/SiNWs/p-Si/Al were fabricated. The electrical characterization (I–V was performed in primary vacuum and H2 at different concentrations. It was found that the metal type used to modify the SiNWs strongly influenced the I–V characteristics. The response of these structures toward H2 gas was studied as a function of the metal type. Finally, the sensing characteristics and performance of the sensors were investigated.

  14. Graphene oxide and H2 production from bioelectrochemical graphite oxidation.

    Science.gov (United States)

    Lu, Lu; Zeng, Cuiping; Wang, Luda; Yin, Xiaobo; Jin, Song; Lu, Anhuai; Jason Ren, Zhiyong

    2015-11-17

    Graphene oxide (GO) is an emerging material for energy and environmental applications, but it has been primarily produced using chemical processes involving high energy consumption and hazardous chemicals. In this study, we reported a new bioelectrochemical method to produce GO from graphite under ambient conditions without chemical amendments, value-added organic compounds and high rate H2 were also produced. Compared with abiotic electrochemical electrolysis control, the microbial assisted graphite oxidation produced high rate of graphite oxide and graphene oxide (BEGO) sheets, CO2, and current at lower applied voltage. The resultant electrons are transferred to a biocathode, where H2 and organic compounds are produced by microbial reduction of protons and CO2, respectively, a process known as microbial electrosynthesis (MES). Pseudomonas is the dominant population on the anode, while abundant anaerobic solvent-producing bacteria Clostridium carboxidivorans is likely responsible for electrosynthesis on the cathode. Oxygen production through water electrolysis was not detected on the anode due to the presence of facultative and aerobic bacteria as O2 sinkers. This new method provides a sustainable route for producing graphene materials and renewable H2 at low cost, and it may stimulate a new area of research in MES.

  15. On the theory of phase transitions in polypeptides

    DEFF Research Database (Denmark)

    Yakubovich, Alexander V.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2008-01-01

    We suggest a theoretical method based on the statistical mechanics for treating the alpha-helix random coil transition in polypeptides. This process is considered as a first-order-like phase transition. The developed theory is free of model parameters and is based solely on fundamental physical...... principles. We apply the developed formalism for the description of thermodynamical properties of alanine polypeptides of different length. We analyze the essential thermodynamical properties of the system such as heat capacity, phase transition temperature and latent heat of the phase transition...

  16. High throughput measurement of γH2AX DSB repair kinetics in a healthy human population.

    Directory of Open Access Journals (Sweden)

    Preety M Sharma

    Full Text Available The Columbia University RABiT (Rapid Automated Biodosimetry Tool quantifies DNA damage using fingerstick volumes of blood. One RABiT protocol quantifies the total γ-H2AX fluorescence per nucleus, a measure of DNA double strand breaks (DSB by an immunofluorescent assay at a single time point. Using the recently extended RABiT system, that assays the γ-H2AX repair kinetics at multiple time points, the present small scale study followed its kinetics post irradiation at 0.5 h, 2 h, 4 h, 7 h and 24 h in lymphocytes from 94 healthy adults. The lymphocytes were irradiated ex vivo with 4 Gy γ rays using an external Cs-137 source. The effect of age, gender, race, ethnicity, alcohol use on the endogenous and post irradiation total γ-H2AX protein yields at various time points were statistically analyzed. The endogenous γ-H2AX levels were influenced by age, race and alcohol use within Hispanics. In response to radiation, induction of γ-H2AX yields at 0.5 h and peak formation at 2 h were independent of age, gender, ethnicity except for race and alcohol use that delayed the peak to 4 h time point. Despite the shift in the peak observed, the γ-H2AX yields reached close to baseline at 24 h for all groups. Age and race affected the rate of progression of the DSB repair soon after the yields reached maximum. Finally we show a positive correlation between endogenous γ-H2AX levels with radiation induced γ-H2AX yields (RIY (r=0.257, P=0.02 and a negative correlation with residuals (r=-0.521, P=<0.0001. A positive correlation was also observed between RIY and DNA repair rate (r=0.634, P<0.0001. Our findings suggest age, race, ethnicity and alcohol use influence DSB γ-H2AX repair kinetics as measured by RABiT immunofluorescent assay.

  17. H2S AND NO SIGNALING INTERACTIONS IN THALE CRESS (ARABIDOPSIS THALIANA L. AND PEPPER (CAPSICUM ANNUUM L. LEAVES

    Directory of Open Access Journals (Sweden)

    Miroslav Lisjak

    2012-06-01

    Full Text Available This research comprehends a set of experiments with several thale cress (Arabidopsis thaliana L. and pepper (Capsicum annuum L. genotypes in controlled conditions using growth chambers, with the aim of determining the physiological role of hydrogen sulfide (H2S in plants, as well as its potential effect as a signaling compound, particularly in potential interaction with nitric oxide (NO signaling pathways. Special emphasis was focused on stomatal mechanisms and signaling in their opening and closing. Moreover, the effect of treatment of pepper plants with H2S was investigated in salt stress conditions. It was established that the applied H2S donors, NaHS and GYY4137, inhibit stomata closing in both plant species through the reduction of NO accumulation in stomata, which was proven to occur in SNP or ABA treatment. The effects of NO and H2S were opposite those in pepper plants response to salt stress as well, with increased antioxidative activity in leaf obtained after H2S treatments, and with NaHS in particular. In addition, GYY4137 could be considered as a convenient H2S donor for research into H2S functions in plants. The results point out the interactions of H2S and NO in plant cell signaling in both normal and salt stress conditions. Further research of this type should uncover H2S functions in plant metabolism more precisely, especially considering the potential practical value of this knowledge for plant stress resistance improvement and their productivity enhancement.

  18. Rotational excitation of H2O by para-H2 from an adiabatically reduced dimensional potential.

    Science.gov (United States)

    Scribano, Yohann; Faure, Alexandre; Lauvergnat, David

    2012-03-07

    Cross sections and rate coefficients for low lying rotational transitions in H(2)O colliding with para-hydrogen pH(2) are computed using an adiabatic approximation which reduces the dimensional dynamics from a 5D to a 3D problem. Calculations have been performed at the close-coupling level using the recent potential of Valiron et al. [J. Chem. Phys. 129, 134306 (2008)]. A good agreement is found between the reduced adiabatic calculations and the 5D exact calculations, with an impressive time saving and memory gain. This adiabatic reduction of dimensionality seems very promising for scattering studies involving the excitation of a heavy target molecule by a light molecular projectile. © 2012 American Institute of Physics

  19. Mesospheric H2O and H2O2 densities inferred from in situ positive ion composition measurement

    Science.gov (United States)

    Kopp, E.

    1984-01-01

    A model for production and loss of oxonium ions in the high-latitude D-region is developed, based on the observed excess of 34(+) which has been interpreted as H2O2(+). The loss mechanism suggested in the study is the attachment of N2 and/or CO2 in three-body reactions. Furthermore, mesospheric water vapor and H2O2 densities are inferred from measurements of four high-latitude ion compositions, based on the oxonium model. Mixing ratios of hydrogen peroxide of up to two orders of magnitude higher than previous values were obtained. A number of reactions, reaction constants, and a block diagram of the oxonium ion chemistry in the D-region are given.

  20. The ultraviolet photochemistry of diacetylene - Direct detection of primary products of the metastable C4H2* + C4H2 reaction

    Science.gov (United States)

    Bandy, Ralph E.; Lakshminarayan, Chitra; Frost, Rex K.; Zwier, Timothy S.

    1993-01-01

    The products of diacetylene's ultraviolet photochemistry over the 245-220 nm region were directly determined in experiments where C4H2 was excited within a small reaction tube attached to a pulsed nozzle. The products formed in the collisions of C4H2* with C4H2 were subsequently ionized by vacuum UV radiation (at 118 nm) in the ion source of a time-of-flight mass spectrometer. It was found that the reaction of C4H2* with C4H2 produces C6H2 (+C2H2), C8H2 (+2H,H2), and C8H3 (+H), confirming the results of Glicker and Okabe (1987). Under certain conditions, secondary products were observed. Mechanisms for the observed reactions are proposed.

  1. Ultrafast phosphate hydration dynamics in bulk H2O

    International Nuclear Information System (INIS)

    Costard, Rene; Tyborski, Tobias; Fingerhut, Benjamin P.; Elsaesser, Thomas

    2015-01-01

    Phosphate vibrations serve as local probes of hydrogen bonding and structural fluctuations of hydration shells around ions. Interactions of H 2 PO 4 − ions and their aqueous environment are studied combining femtosecond 2D infrared spectroscopy, ab-initio calculations, and hybrid quantum-classical molecular dynamics (MD) simulations. Two-dimensional infrared spectra of the symmetric (ν S (PO 2 − )) and asymmetric (ν AS (PO 2 − )) PO 2 − stretching vibrations display nearly homogeneous lineshapes and pronounced anharmonic couplings between the two modes and with the δ(P-(OH) 2 ) bending modes. The frequency-time correlation function derived from the 2D spectra consists of a predominant 50 fs decay and a weak constant component accounting for a residual inhomogeneous broadening. MD simulations show that the fluctuating electric field of the aqueous environment induces strong fluctuations of the ν S (PO 2 − ) and ν AS (PO 2 − ) transition frequencies with larger frequency excursions for ν AS (PO 2 − ). The calculated frequency-time correlation function is in good agreement with the experiment. The ν(PO 2 − ) frequencies are mainly determined by polarization contributions induced by electrostatic phosphate-water interactions. H 2 PO 4 − /H 2 O cluster calculations reveal substantial frequency shifts and mode mixing with increasing hydration. Predicted phosphate-water hydrogen bond (HB) lifetimes have values on the order of 10 ps, substantially longer than water-water HB lifetimes. The ultrafast phosphate-water interactions observed here are in marked contrast to hydration dynamics of phospholipids where a quasi-static inhomogeneous broadening of phosphate vibrations suggests minor structural fluctuations of interfacial water

  2. Ultrafast phosphate hydration dynamics in bulk H2O

    Science.gov (United States)

    Costard, Rene; Tyborski, Tobias; Fingerhut, Benjamin P.; Elsaesser, Thomas

    2015-06-01

    Phosphate vibrations serve as local probes of hydrogen bonding and structural fluctuations of hydration shells around ions. Interactions of H2PO4- ions and their aqueous environment are studied combining femtosecond 2D infrared spectroscopy, ab-initio calculations, and hybrid quantum-classical molecular dynamics (MD) simulations. Two-dimensional infrared spectra of the symmetric ( ν S ( PO2 - ) ) and asymmetric ( ν A S ( PO2 - ) ) PO 2- stretching vibrations display nearly homogeneous lineshapes and pronounced anharmonic couplings between the two modes and with the δ(P-(OH)2) bending modes. The frequency-time correlation function derived from the 2D spectra consists of a predominant 50 fs decay and a weak constant component accounting for a residual inhomogeneous broadening. MD simulations show that the fluctuating electric field of the aqueous environment induces strong fluctuations of the ν S ( PO2 - ) and ν A S ( PO2 - ) transition frequencies with larger frequency excursions for ν A S ( PO2 - ) . The calculated frequency-time correlation function is in good agreement with the experiment. The ν ( PO2 - ) frequencies are mainly determined by polarization contributions induced by electrostatic phosphate-water interactions. H2PO4-/H2O cluster calculations reveal substantial frequency shifts and mode mixing with increasing hydration. Predicted phosphate-water hydrogen bond (HB) lifetimes have values on the order of 10 ps, substantially longer than water-water HB lifetimes. The ultrafast phosphate-water interactions observed here are in marked contrast to hydration dynamics of phospholipids where a quasi-static inhomogeneous broadening of phosphate vibrations suggests minor structural fluctuations of interfacial water.

  3. Identification of polypeptides by using SOM neural networks

    Science.gov (United States)

    Liu, Jianwei; He, Ting; Zhang, Bo; Shen, Jingling

    2014-11-01

    Sample with no characteristic absorption can be identified by refractive index features. In this work, qualitative and quantitative identification of THz spectra of polypeptides using self-organization feature map (SOM) artificial neural network has been demonstrated. The absorption and refractive index features of three polypeptides, including Argreline Acetate, Alarelin Acetate, and Bivalirudin Trifluoroacetate, were measured by using the terahertz time-domain spectroscopy technique in the range 0.2-2.2 THz. The experimental results show that the three measured polypeptides present high similarity in absorption spectra but difference in refractive index spectra. After the network training process, the collected spectra were identified by the well-trained SOM network at another time. Analyzing the result we can see that the refractive index spectra are clustered and identify much better than the THz spectra of polypeptides. The study indicates that refractive index spectra can also be clustered by the SOM artificial neural network for identification of THz spectra especially when there is no obvious difference in absorption but significant difference in refractive index spectra.

  4. Vasoactive intestinal polypeptide (VIP) in the pig pancreas

    DEFF Research Database (Denmark)

    Poulsen, Steen Seier

    1984-01-01

    Vasoactive intestinal polypeptide (VIP) in the pig pancreas is localized to nerves, many of which travel along the pancreatic ducts. VIP stimulates pancreatic fluid and bicarbonate secretion like secretin. Electrical vagal stimulation in the pig causes an atropine-resistant profuse secretion...

  5. CLE polypeptide signaling gene expression in Arabidopsis embryos

    Science.gov (United States)

    Technical Abstract: The CLAVATA3 (CLV3)/ESR-related (CLE) family of small polypeptides mediate intercellular signaling events in plants. The biological roles of several CLE family members have been characterized, but the function of the majority still remains elusive. We recently performed a system...

  6. Discovery and Characterization of A Novel Class of Functional Polypeptides

    Science.gov (United States)

    Chu, Qian; Ma, Jiao; Saghatelian, Alan

    2015-01-01

    Molecular biology, genomics and proteomics methods have been utilized to reveal a non-annotated class of endogenous polypeptides (small proteins and peptides) encoded by short open reading frames (sORFs), or small open reading frames (smORFs). We refer to these polypeptides as s(m)ORF-encoded polypeptides or SEPs. The early SEPs were identified via genetic screens, and many of the RNAs that contain s(m)ORFs were originally considered to be non-coding; however, elegant work in bacteria and flies demonstrated that these s(m)ORFs code for functional polypeptides as small as 11-amino acids in length. The discovery of these initial SEPs led to searches for these molecules using methods such as ribosome profiling and proteomics, which have revealed the existence of many SEPs, including novel human SEPs. Unlike screens, –omics methods do not necessarily link a SEP to a cellular or biological function, but functional genomic and proteomic strategies have demonstrated that at least some of these newly discovered SEPs have biochemical and cellular functions. Here, we provide an overview of these results and discuss the future directions in this emerging field. PMID:25857697

  7. Immunohistochemical localization of pancreatic spasmolytic polypeptide (PSP) in the pig

    DEFF Research Database (Denmark)

    Raaberg, Lasse; Poulsen, Steen Seier; Thim, L

    1992-01-01

    Pancreatic spasmolytic polypeptide (PSP) is a peptide that is isolated from the porcine pancreas and that affects intestinal motility and growth of intestinal tumour cells in vitro. The peptide was recently demonstrated to be present in large amounts in pancreatic juice. The cellular origin...

  8. Identification and characterization of sORF-encoded polypeptides.

    Science.gov (United States)

    Chu, Qian; Ma, Jiao; Saghatelian, Alan

    2015-01-01

    Molecular biology, genomics and proteomics methods have been utilized to reveal a non-annotated class of endogenous polypeptides (small proteins and peptides) encoded by short open reading frames (sORFs), or small open reading frames (smORFs). We refer to these polypeptides as s(m)ORF-encoded polypeptides or SEPs. The early SEPs were identified via genetic screens, and many of the RNAs that contain s(m)ORFs were originally considered to be non-coding; however, elegant work in bacteria and flies demonstrated that these s(m)ORFs code for functional polypeptides as small as 11-amino acids in length. The discovery of these initial SEPs led to search for these molecules using methods such as ribosome profiling and proteomics, which have revealed the existence of many SEPs, including novel human SEPs. Unlike screens, omics methods do not necessarily link a SEP to a cellular or biological function, but functional genomic and proteomic strategies have demonstrated that at least some of these newly discovered SEPs have biochemical and cellular functions. Here, we provide an overview of these results and discuss the future directions in this emerging field.

  9. Chirality-selected phase behavior in ionic polypeptide complexes

    Science.gov (United States)

    Tirrell, Matthew

    2015-03-01

    We demonstrate that chirality determines the phase state of polyelectrolyte complexes formed from mixing dilute solutions of oppositely charged polypeptides. In these systems, the physical state of the resultant complex is determined by the combination of electrostatic and hydrogen bonding interactions. The formation of fluid complexes occurs when at least one of the polypeptides in the mixture is racemic, which disrupts backbone hydrogen bonding networks. Pairs of purely chiral polypeptides, of any sense, form compact, fibrillar solids with a β-sheet structure on mixing. Analogous behavior occurs in micellar cores formed from polypeptide block copolymers with polyethylene oxide, where microphase separation into discrete, self-assembled aggregates with either solid or fluid cores, and eventually into ordered phases at high concentrations, is possible. Chirality is an exploitable tool for manipulating material properties in systems based on polyelectrolyte complexation. Its role in these systems gives insight into polyelectrolyte complex phase behavior more broadly. This work was supported by the U.S. Department of Energy Office of Science Program in Basic Energy Sciences, Materials Sciences and Engineering Division.

  10. Research progress of active polypeptides of Cordyceps militaris

    Directory of Open Access Journals (Sweden)

    Xu Guangyu

    2017-01-01

    Full Text Available It is recognized at home and abroad that Cordyceps militaris is a fungus that can be edible and used for medicinal application, and also a common cordyceps taishanensis that is widely distributed and with very high medicinal value in China. Active Cordyceps militaris polypeptide has shown several highlights in its absorption mechanism, such as directly absorbed without the need for digestion, and absorbed quickly and completely, and more and more international researchers are attaching great importance to it. Physiological and pharmacological activities of Cordyceps militaris polypeptide are mainly to activate related enzyme systems, promote intermediary metabolisms or control the DNA transcription and translation, simultaneously activate the reticuloendothelial system and macrophage, promote the transformation of lymphocytes, and as a nonspecific immune enhancer and regulator, activate the immune competent cells, especially lymphocytes, lymphokines, mononuclear macrophage system and NK cells, thereby attacking the target cells to play an antitumor role, and also exerting its anti-aging, anticoagulant, hypolipidemic to enhance the immunity, improve the liver function and delay the aging. In this paper, the immunity improvement, anticancer, antioxidation and antimicrobial activities of active polypeptides from Cordyceps militaris are reviewed, in order to provide a solid theoretical help for the further development and application of active polypeptides of Cordyceps militaris.

  11. Multiobjective H2/H? Control Design with Regional Pole Constraints

    Directory of Open Access Journals (Sweden)

    Junaidi Junaidi

    2012-03-01

    Full Text Available This paper presents multiobjective H2/H? control design with regional pole constraints. The state feedback gain can be obtained by solving a linear matrix inequality (LMI feasibility problem that robustly assigns the closed-loop poles in a prescribed LMI region. The proposed technique is illustrated with applications to the design of stabilizer for a typical single-machine infinite-bus (SMIB power system. The LMI-based control ensures adequate damping for widely varying system operating conditions. The simulation results illustrate the effectiveness and robustness of the proposed stabilizer.

  12. H2O maser flare in Orion A

    International Nuclear Information System (INIS)

    Matveenko, L.I.; Moran, J.M.; Genzel, R.

    1982-01-01

    The flare of H 2 O maser emission in Orion A was observed with the Crimea--Effelsberg and Haystack--Green Bank interferometers in November 1979. Its position is α = 5/sup h/32/sup m/46/sup s/.6 +- 0/sup s/.06, delta = -5 0 24'.28''.7 +- 1'' (1950.0); its radial velocity, 8 km/sec. The asymmetric line profile has a 28-kHz halfwidth. The flare source comprises a 0''.0005 core (T/sub b/ = 5 x 10 16 0 K) embedded in a 0''.005 halo (T/sub b/ = 3 x 10 14 0 K)

  13. Testing of irradiated and annealed 15H2MFA materials

    International Nuclear Information System (INIS)

    Gillemot, F.; Uri, G.

    1994-01-01

    A set of surveillance samples made from 15H2MFA material has been studied in the laboratory of AEKI. Miniature notched tensile specimens were cut from some remnants of irradiated and broke surveillance charpy remnants. The Absorbed Specific Fracture Energy (ASFE) was measured on the specimens. A cutting machine and testing technique were elaborated for the measurements. The second part of the Charpy remnants was annealed at 460 deg. C and 490 deg. C for 6-8 hours. The specimens were tested similarity and the results were compared. (author). 5 refs, 9 figs

  14. Hydrogen Learning for Local Leaders – H2L3

    Energy Technology Data Exchange (ETDEWEB)

    Serfass, Patrick [Technology Transition Corporation, Washington, DC (United States)

    2017-03-30

    The Hydrogen Learning for Local Leaders program, H2L3, elevates the knowledge about hydrogen by local government officials across the United States. The program reaches local leaders directly through “Hydrogen 101” workshops and webinar sessions; the creation and dissemination of a unique report on the hydrogen and fuel cell market in the US, covering 57 different sectors; and support of the Hydrogen Student Design Contest, a competition for interdisciplinary teams of university students to design hydrogen and fuel cell systems based on technology that’s currently commercially available.

  15. CodY Regulates Thiol Peroxidase Expression as Part of the Pneumococcal Defense Mechanism against H2O2 Stress.

    Science.gov (United States)

    Hajaj, Barak; Yesilkaya, Hasan; Shafeeq, Sulman; Zhi, Xiangyun; Benisty, Rachel; Tchalah, Shiran; Kuipers, Oscar P; Porat, Nurith

    2017-01-01

    Streptococcus pneumoniae is a facultative anaerobic pathogen. Although it maintains fermentative metabolism, during aerobic growth pneumococci produce high levels of H 2 O 2 , which can have adverse effects on cell viability and DNA, and influence pneumococcal interaction with its host. The pneumococcus is unusual in its dealing with toxic reactive oxygen species (ROS) in that it neither has catalase nor the global regulators of peroxide stress resistance. Previously, we identified pneumococcal thiol peroxidase (TpxD) as the key enzyme for enzymatic removal of H 2 O 2 , and showed that TpxD synthesis is up-regulated upon exposure to H 2 O 2 . This study aimed to reveal the mechanism controlling TpxD expression under H 2 O 2 stress. We hypothesize that H 2 O 2 activates a transcription factor which in turn up-regulates tpxD expression. Microarray analysis revealed a pneumococcal global transcriptional response to H 2 O 2 . Mutation of tpxD abolished H 2 O 2 -mediated response to high H 2 O 2 levels, signifying the need for an active TpxD under oxidative stress conditions. Bioinformatic tools, applied to search for a transcription factor modulating tpxD expression, pointed toward CodY as a potential candidate. Indeed, a putative 15-bp consensus CodY binding site was found in the proximal region of tpxD- coding sequence. Binding of CodY to this site was confirmed by EMSA, and genetic engineering techniques demonstrated that this site is essential for TpxD up-regulation under H 2 O 2 stress. Furthermore, tpxD expression was reduced in a Δ codY mutant. These data indicate that CodY is an activator of tpxD expression, triggering its up-regulation under H 2 O 2 stress. In addition we show that H 2 O 2 specifically oxidizes the 2 CodY cysteines. This oxidation may trigger a conformational change in CodY, resulting in enhanced binding to DNA. A schematic model illustrating the contribution of TpxD and CodY to pneumococcal global transcriptional response to H 2 O 2 is

  16. CodY Regulates Thiol Peroxidase Expression as Part of the Pneumococcal Defense Mechanism against H2O2 Stress

    Directory of Open Access Journals (Sweden)

    Barak Hajaj

    2017-05-01

    Full Text Available Streptococcus pneumoniae is a facultative anaerobic pathogen. Although it maintains fermentative metabolism, during aerobic growth pneumococci produce high levels of H2O2, which can have adverse effects on cell viability and DNA, and influence pneumococcal interaction with its host. The pneumococcus is unusual in its dealing with toxic reactive oxygen species (ROS in that it neither has catalase nor the global regulators of peroxide stress resistance. Previously, we identified pneumococcal thiol peroxidase (TpxD as the key enzyme for enzymatic removal of H2O2, and showed that TpxD synthesis is up-regulated upon exposure to H2O2. This study aimed to reveal the mechanism controlling TpxD expression under H2O2 stress. We hypothesize that H2O2 activates a transcription factor which in turn up-regulates tpxD expression. Microarray analysis revealed a pneumococcal global transcriptional response to H2O2. Mutation of tpxD abolished H2O2-mediated response to high H2O2 levels, signifying the need for an active TpxD under oxidative stress conditions. Bioinformatic tools, applied to search for a transcription factor modulating tpxD expression, pointed toward CodY as a potential candidate. Indeed, a putative 15-bp consensus CodY binding site was found in the proximal region of tpxD-coding sequence. Binding of CodY to this site was confirmed by EMSA, and genetic engineering techniques demonstrated that this site is essential for TpxD up-regulation under H2O2 stress. Furthermore, tpxD expression was reduced in a ΔcodY mutant. These data indicate that CodY is an activator of tpxD expression, triggering its up-regulation under H2O2 stress. In addition we show that H2O2 specifically oxidizes the 2 CodY cysteines. This oxidation may trigger a conformational change in CodY, resulting in enhanced binding to DNA. A schematic model illustrating the contribution of TpxD and CodY to pneumococcal global transcriptional response to H2O2 is proposed.

  17. Acetylene C2H 2 retrievals from MIPAS data and regions of enhanced upper tropospheric concentrations in August 2003

    Directory of Open Access Journals (Sweden)

    V. P. Kanawade

    2011-10-01

    Full Text Available Acetylene (C2H2 volume mixing ratios (VMRs have been successfully retrieved from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS Level 1B radiances during August 2003, providing the first global map of such data and ratios to CO in the literature. The data presented here contain most information between 300 hPa and 100 hPa with systematic errors less than 10% at the upper levels. Random errors per point are less than 15% at lower levels and are closer to 30% at 100 hPa. Global distributions of the C2H2 and C2H2/CO ratio confirm significant features associated with both the Asian monsoon anticyclone and biomass burning for this important hydrocarbon in a characteristic summer month (August 2003, showing tight correlations regionally, particularly at lower to medium values, but globally emphasising the differences between sources and lifetimes of CO and C2H2. The correlations are seen to be particularly disturbed in the regions of highest C2H2 concentrations, indicating variability in the surface emissions or fast processing. A strong isolation of C2H2 within the Asian monsoon anticyclone is observed, evidencing convective transport into the upper troposphere, horizontal advection within the anticyclone at 200 hPa, distinct gradients at the westward edge of the vortex and formation of a secondary dynamical feature from the eastward extension of the anticyclone outflow over the Asian Pacific. Ratios of C2H2/CO are consistent with the evidence from the cross-sections that the C2H2 is uplifted rapidly in convection. Observations are presented of enhanced C2H2 associated with the injection from biomass burning into the upper troposphere and the outflow from Africa at 200 hPa into both the Atlantic and Indian Oceans. In the biomass burning regions, C2H2 and CO are well correlated, but the uplift is less marked and peaks at lower altitudes compared to the strong effects observed in the Asian monsoon anticyclone. Ratios of C2H2/CO

  18. H + H2 reaction barrier: A fixed-node quantum Monte Carlo study

    International Nuclear Information System (INIS)

    Barnett, R.N.; Reynolds, P.J.; Lester, W.A. Jr.

    1985-01-01

    The classical barrier height for the H+H 2 exchange reaction, as well as the energies at two other points along the reaction path, are calculated using fixed-node quantum Monte Carlo (FNQMC). Several single-determinant importance functions are used at the saddle point in order to relate the quality of the importance function to the accuracy and precision of the final result. The computed barrier is an upper bound since the energy of H and of H 2 is obtained exactly by FNQMC. Our best upper bound (9.70 +- 0.13 kcal/mol) has a mean within 0.1 kcal/mol of the presumed exact value. This best bound is obtained with a single determinant, double-zeta basis importance function. Contrary to experience with expansion methods, it is found that an importance function with a basis set of near Hartree--Fock quality, as well as one derived from a spin-unrestricted SCF calculation, are among the least efficient and least accurate of the importance functions used. Specifically, a nodal surface appearing in the lowest energy molecular orbital in these functions apparently increases the FNQMC energy. The FNQMC energy at the two other points along the reaction path is found to agree with the most accurate CI results of Liu to within statistical error

  19. First principle investigations of the physical properties of hydrogen-rich MgH2

    KAUST Repository

    Zarshenas, Mohammed

    2013-11-28

    Hydrogen being a cleaner energy carrier has increased the importance of hydrogen-containing light metal hydrides, in particular those with large gravimetric hydrogen density like magnesium hydride (MgH2). In this study, density functional and density functional perturbation theories are combined to investigate the structural, elastic, thermodynamic, electronic and optical properties of MgH2. Our structural parameters calculated with those proposed by Perdew, Burke and Ernzerof generalized gradient approximation (PBE-GGA) and Wu-Cohen GGA (WC-GGA) are in agreement with experimental measurements, however the underestimated band gap values calculated using PBE-GGA and WC-GGA were greatly improved with the GGA suggested by Engle and Vosko and the modified Becke-Johnson exchange correlation potential by Trans and Blaha. As for the thermodynamic properties the specific heat values at low temperatures were found to obey the T3 rule and at higher temperatures Dulong and Petit\\'s law. Our analysis of the optical properties of MgH2 also points to its potential application in optoelectronics. © 2013 The Royal Swedish Academy of Sciences.

  20. Revisiting the Helical Cooperativity of Synthetic Polypeptides in Solution.

    Science.gov (United States)

    Ren, Yuan; Baumgartner, Ryan; Fu, Hailin; van der Schoot, Paul; Cheng, Jianjun; Lin, Yao

    2017-08-14

    Using synthetic polypeptides as a model system, the theories of helix-coil transition were developed into one of the most beautiful and fruitful subjects in macromolecular science. The classic models proposed by Schellman and Zimm-Bragg more than 50 years ago, differ in the assumption on whether the configuration of multiple helical sequences separated by random coil sections is allowed in a longer polypeptide chain. Zimm also calculated the critical chain lengths that facilitate such interrupted helices in different solvent conditions. The experimental validation of Zimm's prediction, however, was not carefully examined at that time. Herein, we synthesize a series of homopolypeptide samples with different lengths, to systematically examine their helix-coil transition and folding cooperativity in solution. We find that for longer chains, polypeptides do exist as interrupted helices with scattered coil sections even in helicogenic solvent conditions, as predicted in the Zimm-Bragg model. The critical chain lengths that facilitate such interrupted helices, however, are substantially smaller than Zimm's original estimation. The inaccuracy is in part due to an approximation that Zimm made in simplifying the calculation. But more importantly, we find there exist intramolecular interactions between different structural segments in the longer polypeptides, which are not considered in the classic helix-coil theories. As such, even the Zimm-Bragg model in its exact form cannot fully describe the transition behavior and folding cooperativity of longer polypeptides. The results suggest that long "all-helix" chains may be much less prevalent in solution than previously imagined, and a revised theory is required to accurately account for the helix-coil transition of the longer chains with potential "non-local" intramolecular interactions.

  1. Polypeptides having beta-glucosidase activity and polynucleotides encoding the same

    Science.gov (United States)

    Brown, Kimberly; Harris, Paul

    2013-12-17

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  2. Polypeptides having beta-glucosidase and beta-xylosidase activity and polynucleotides encoding same

    Science.gov (United States)

    Morant, Marc Dominique

    2014-05-06

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  3. Recombinant host cells and nucleic acid constructs encoding polypeptides having cellulolytic enhancing activity

    Science.gov (United States)

    Schnorr, Kirk; Kramer, Randall

    2017-03-28

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  4. Polypeptides having beta-glucosidase activity and beta-xylosidase activity and polynucleotides encoding same

    Science.gov (United States)

    Morant, Marc Dominique

    2014-04-29

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  5. Continued fractions and the hydrogen molecular ion H2+

    Science.gov (United States)

    Nickel, Bernie

    2011-09-01

    The Jaffé continued fraction solution for the hydrogen molecular ion has been the basis for most H2+ energy calculations at physically relevant nuclear separation R. I show that its slow convergence at small R can be overcome so it can also be used to obtain the power series expansion of the energy about the united atom limit R = 0. I restrict the discussion to the H2+ ground state and show, by a generalization of Wynn's accelerated convergence technique and an analytical calculation, that the continued fraction yields the O(R5) series term which is the first term in which log(R) makes an appearance. For higher order terms I apply the convergence method numerically to obtain very accurate energies at small R and, by fitting, numerical coefficients in the R series. The analytic representations of the coefficients are identified using the integer relation algorithm PSLQ. All terms to O(R14) are obtained exactly and to O(R20) in a mixed analytic/numeric form. Comparisons with previous work based on wavefunction perturbation theory are made.

  6. Continued fractions and the hydrogen molecular ion H2+

    International Nuclear Information System (INIS)

    Nickel, Bernie

    2011-01-01

    The Jaffe continued fraction solution for the hydrogen molecular ion has been the basis for most H 2 + energy calculations at physically relevant nuclear separation R. I show that its slow convergence at small R can be overcome so it can also be used to obtain the power series expansion of the energy about the united atom limit R = 0. I restrict the discussion to the H 2 + ground state and show, by a generalization of Wynn's accelerated convergence technique and an analytical calculation, that the continued fraction yields the O(R 5 ) series term which is the first term in which log(R) makes an appearance. For higher order terms I apply the convergence method numerically to obtain very accurate energies at small R and, by fitting, numerical coefficients in the R series. The analytic representations of the coefficients are identified using the integer relation algorithm PSLQ. All terms to O(R 14 ) are obtained exactly and to O(R 20 ) in a mixed analytic/numeric form. Comparisons with previous work based on wavefunction perturbation theory are made. (paper)

  7. Experimental evidence of superionic conduction in H2O ice.

    Science.gov (United States)

    Sugimura, Emiko; Komabayashi, Tetsuya; Ohta, Kenji; Hirose, Kei; Ohishi, Yasuo; Dubrovinsky, Leonid S

    2012-11-21

    Ionic conductivity and molar volume measurements were performed on H(2)O ice at high pressure (P) and temperature (T) in a resistive-heated diamond anvil cell. The conductivity data obtained at P = 20-62 GPa, T = 304-930 K are well fitted with a single Arrhenius equation. Isothermal volume measurements at T = 873 K, P = 30-101 GPa indicate that H(2)O ice undergoes phase transitions at P = 50 GPa and 53 GPa due to hydrogen-bond symmetrization. Combining these results, we suggest that the conduction mechanism does not change with pressure-induced hydrogen-bond symmetrization. Along the Arrhenius behavior of conductivity data, the experimental evidence for superionic conduction (>10(-1) S/cm) was found at T = 739 K, P = 56 GPa and T = 749 K, P = 62 GPa, which is significantly low temperature compared with earlier theoretical estimates resorted to the observation of a drastic rise of the melting curve. We infer that the sudden increase of the melting temperature is not related to the onset of superionic conduction, but is attributed to the phase change regarding to the symmetrization.

  8. Structure of solid H2-D2 mixtures

    International Nuclear Information System (INIS)

    Krupskij, I.N.; Kovalenko, S.I.; Krajnyukova, N.V.

    1978-01-01

    The structure of vapor deposited H 2 -D 2 solid mixtures is investigated. The electron-diffraction examination has been carried out in the temperature range from 2.3K up to the sample sublimation temperature, taking place in case of H 2 at T approximately 5K and D 2 -at T approximately 7K. On the basis of the difractogramm obtained it is shown that in solid films of pure components a FCC structure with parameters asub(Hsub(2))=5.310+-0.01A and asub(Osub(2))=5.100+-0.005A is realized, the structure being metastable in the temperature range. The existence of non-limitted solubility in solid two-component condensates is stated. The decay absence at T approximately 5K, when molecula mobility is enough for the transition of metastable FCC structure into HCP, is in good agreement with the results of experimental and theoretical estimations, according to which the decay critical temperature should not exceed 4K. The existance of the continuous series of solutions at lower temperatures is explained by a small coefficient value of a volumetric and surface diffusion of molecula as well

  9. Space Station Freedom NiH2 cell testing program

    Science.gov (United States)

    Moore, Bruce; Frate, Dave

    1994-02-01

    Testing for the Space Station Freedom Nickel Hydrogen Cell Test Program began in 1990 at Crave Division, Naval Surface Warfare Center. The program has included receipt inspection, random vibration, acceptance, characterization, and life cycle testing of Ni-H2 cells in accordance with the NASA LeRC Interagency Order C-31001-J. A total of 400 Ni-H2 cells have been received at NAVSURFWARCENDIV Crane from three separate manufacturers; Yardney Technical Products (Yardney), Eagle Picher Industries (Eagle Picher), and Gates Energy Products (Gates). Of those, 308 cells distributed among 39 packs have undergone life cycle testing under a test regime simulating low earth orbit conditions. As of 30 September 1993, there are 252 cells assembled into 32 packs still on life cycle test. Since the beginning of the program, failed cells have been detected in all phases of testing. The failures include the following; seven 65 AmpHr and 81 AmpHr Yardney cells were found to be leaking KOH on receipt, one 65 AmpHr Eagle Picher cell failed the acceptance test, one 65 AmpHr Gates cell failed during the characterization test, and six 65 AmpHr Gates cells failed the random vibration test. Of the 39 life cycle packs, testing on seven packs, 56 cells, has been suspended because of low end of discharge voltages. All of the failed life cycle packs were cycled at 60% depth of discharge.

  10. Determination of structural, thermodynamic and phase properties in the Na2S-H2O system for application in a chemical heat pump

    International Nuclear Information System (INIS)

    Boer, R. de; Haije, W.G.; Veldhuis, J.B.J.

    2002-01-01

    Structural, thermodynamic and phase properties in the Na 2 S-H 2 O system for application in a chemical heat pump have been investigated using XRD, TG/DTA and melting point and vapour pressure determinations. Apart from the known crystalline phases Na 2 S·9H 2 O, Na 2 S·5H 2 O and Na 2 S a new phase Na 2 S·2H 2 O has been proven to exist. Na 2 S·((1)/(2))H 2 O is not a phase but a 3:1 mixture of Na 2 S and Na 2 S·2H 2 O, presumably stabilised by very slow dehydration kinetics. The vapour pressure-temperature equilibria of the sodium sulphide hydrates have been determined and a consistent set of thermodynamic functions for these compounds has been derived. XRD measurements indicate the topotactic character of the transitions between the hydration states

  11. The structure of gas-phase [Al·nH2O]+: hydrated monovalent aluminium Al+ (H2O)n or hydride-hydroxide HAlOH+ (H2O)(n-1)?

    Science.gov (United States)

    van der Linde, Christian; Beyer, Martin K

    2011-04-21

    Theoretical studies predict that [Al·nH(2)O](+) clusters are present as hydride-hydroxide species HAlOH(+)(H(2)O)(n-1) in gas-phase experiments, energetically favoured by 200 kJ mol(-1) over Al(+)(H(2)O)(n). After collisions with D(2)O, however, no H/D scrambling occurs between H(2)O and D(2)O in clusters with n > 38, indicating that large clusters are present as the higher-energy isomers Al(+)(H(2)O)(n).

  12. The roles of H2S and H2O2 in regulating AsA-GSH cycle in the leaves of wheat seedlings under drought stress.

    Science.gov (United States)

    Shan, Changjuan; Zhang, Shengli; Ou, Xingqi

    2018-01-25

    This paper investigated the roles of hydrogen sulfide (H 2 S) and hydrogen peroxide (H 2 O 2 ) and the possible relationship between them in regulating the AsA-GSH cycle in wheat leaves under drought stress (DS). Results showed that DS markedly increased the production of H 2 S and H 2 O 2 , the transcript levels and activities of ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR); malondialdehyde (MDA) content; and electrolyte leakage (EL). Meanwhile, DS markedly reduced plant height and biomass. Above increases induced by drought stress except MDA content and EL were all suppressed by pretreatments with H 2 S synthesis inhibitor aminooxyaceticacid (AOA) and H 2 O 2 synthesis inhibitor diphenylene iodonium (DPI). Besides, pretreatments with AOA and DPI further significantly increased MDA content and EL and significantly reduced plant height and biomass under DS. DPI reduced the production of H 2 O 2 and H 2 S induced by DS. AOA also reduced the production of H 2 S and H 2 O 2 induced by DS. Pretreatments with NaHS + AOA and H 2 O 2 + DPI reversed above effects of AOA and DPI. Our results suggested that H 2 S and H 2 O 2 all participated in the up-regulation of AsA-GSH cycle in wheat leaves by DS and possibly affected each other.

  13. Laboratory studies of H2SO4/H2O binary homogeneous nucleation from the SO2+OH reaction: evaluation of the experimental setup and preliminary results

    Directory of Open Access Journals (Sweden)

    M. Kulmala

    2008-08-01

    Full Text Available Binary homogeneous nucleation (BHN of sulphuric acid and water (H2SO4/H2O is one of the most important atmospheric nucleation processes, but laboratory observations of this nucleation process are very limited and there are also large discrepancies between different laboratory studies. The difficulties associated with these experiments include wall loss of H2SO4 and uncertainties in estimation of H2SO4 concentration ([H2SO4] involved in nucleation. We have developed a new laboratory nucleation setup to study H2SO4/H2O BHN kinetics and provide relatively constrained [H2SO4] needed for nucleation. H2SO4 is produced from the SO2+OH→HSO3 reaction and OH radicals are produced from water vapor UV absorption. The residual [H2SO4] were measured at the end of the nucleation reactor with a chemical ionization mass spectrometer (CIMS. Wall loss factors (WLFs of H2SO4 were estimated by assuming that wall loss is diffusion limited and these calculated WLFs were in good agreement with simultaneous measurements of the initial and residual [H2SO4] with two CIMSs. The nucleation zone was estimated from numerical simulations based on the measured aerosol sizes (particle diameter, Dp and [H2SO4]. The measured BHN rates (J ranged from 0.01–220 cm−3 s−1 at the initial and residual [H2SO4] from 108−1010 cm−3, a temperature of 288 K and relative humidity (RH from 11–23%; J increased with increasing [H2SO4] and RH. J also showed a power dependence on [H2SO4] with the exponential power of 3–8. These power dependences are consistent with other laboratory studies under similar [H2SO4] and RH, but different from atmospheric field observations which showed that particle number concentrations are often linearly dependent on [H2SO4]. These results, together with a higher [H2SO4] threshold (108–109 cm−3 needed to produce the unit J measured from the laboratory studies compared to the atmospheric conditions (106–107 cm−3, imply that H2SO4/H2O BHN alone is

  14. About the secondary electron emission from solid hydrogens: H2, HD, D2 and T2

    International Nuclear Information System (INIS)

    Cazaux, J.

    2008-01-01

    Reported by Sorensen and Schou [H. Sorensen, J. Schou, J. Appl. Phys. 53 (1982) 5230], the electron-induced secondary electron emission yield curves, δ = f(E 0 ), of condensed hydrogen and deuterium show a significant isotopic effect with a yield for D 2 at about ∼1.5 times larger than that for H 2 and very low values (δ 0 = 3 keV) in contrast to the very large yields (δ > 50 at E 0 = 3 keV) reported, elsewhere, for condensed rare gases. Combined to the use of a recent model, physical considerations on the interaction of secondary electrons with zero point fluctuations permit to suggest a coherent explanation for these facts. The values of SE attenuation for three isotopes are deduced (∼4 nm for H 2 ; ∼5.6 nm for D 2 ; ∼4.9 nm for HD) and the electron-induced secondary electron emission yield curves, δ = f(E 0 ), initially limited to an investigated energy range, 0.5 keV 0 max ∼ 0.95 at E max 0 ∼ 145 eV, for H 2 to δ max ∼ 1.13 at E max 0 ∼ 175 eV for D 2 . From the estimate of the attenuation length of secondary electrons, the same extrapolation procedure is also applied to solid tritium. Some consequences on charging of thick films and of small clusters are deduced. Showing also an isotopic effect, the expected evolution of X-ray-induced secondary electron emission yields, δ X = f(hν), of condensed H 2 , HD, D 2 and T 2 are finally estimated

  15. Experimental and theoretical study of rotationally inelastic diffraction of H2(D2) from methyl-terminated Si(111)

    International Nuclear Information System (INIS)

    Nihill, Kevin J.; Hund, Zachary M.; Sibener, S. J.; Muzas, Alberto; Cueto, Marcos del; Díaz, Cristina; Frankcombe, Terry; Plymale, Noah T.; Lewis, Nathan S.; Martín, Fernando

    2016-01-01

    Fundamental details concerning the interaction between H 2 and CH 3 –Si(111) have been elucidated by the combination of diffractive scattering experiments and electronic structure and scattering calculations. Rotationally inelastic diffraction (RID) of H 2 and D 2 from this model hydrocarbon-decorated semiconductor interface has been confirmed for the first time via both time-of-flight and diffraction measurements, with modest j = 0 → 2 RID intensities for H 2 compared to the strong RID features observed for D 2 over a large range of kinematic scattering conditions along two high-symmetry azimuthal directions. The Debye-Waller model was applied to the thermal attenuation of diffraction peaks, allowing for precise determination of the RID probabilities by accounting for incoherent motion of the CH 3 –Si(111) surface atoms. The probabilities of rotationally inelastic diffraction of H 2 and D 2 have been quantitatively evaluated as a function of beam energy and scattering angle, and have been compared with complementary electronic structure and scattering calculations to provide insight into the interaction potential between H 2 (D 2 ) and hence the surface charge density distribution. Specifically, a six-dimensional potential energy surface (PES), describing the electronic structure of the H 2 (D 2 )/CH 3 −Si(111) system, has been computed based on interpolation of density functional theory energies. Quantum and classical dynamics simulations have allowed for an assessment of the accuracy of the PES, and subsequently for identification of the features of the PES that serve as classical turning points. A close scrutiny of the PES reveals the highly anisotropic character of the interaction potential at these turning points. This combination of experiment and theory provides new and important details about the interaction of H 2 with a hybrid organic-semiconductor interface, which can be used to further investigate energy flow in technologically relevant systems.

  16. Temperature dependence of third order ion molecule reactions. The reaction H+3 + 2H2 = H+5 + H2

    International Nuclear Information System (INIS)

    Hiraoka, K.; Kebarle, P.

    1975-01-01

    The rate constants k 1 for Reaction (1): H + 3 +2H 2 = H + 5 +H 2 were measured in the temperature range 100--300 degreeK. The temperature dependence of k 1 has the form k 1 proportionalT - /subn/, where n=2.3. Pierce and Porter have reported a much stronger negative temperature dependence with n=4.6. The difference arises from a determination of k 1 at 300 degreeK obtained by Arifov and used by Porter. The present k 1 (300 degreeK) =9times10 -30 (cm 6 molecules -2 center-dotsec -1 ). This is more than an order of magnitude larger than the Arifov value. The temperature dependence of third body dependent association reactions like (1) is examined on the basis of the energy transfer theory and the recently proposed trimolecular complex transition state theory by Meot-Ner, Solomon, Field, and Gershinowitz. The temperature dependence of the rate constant for the reverse reaction (-1) is obtained from k 1 and the previously determined temperature dependence of the equilibria (1). k/sub -//sub 1/ gives a good straight line Arrhenius plot leading to k/sub -//sub 1/ =8.7times10 -6 exp(-8.4/RT) cm 3 molecules -1 center-dotsec -1 . The activation energy is in kcal/mole. The preexponential factor is much larger than the rate constant for Langevin collisions. This is typical for pyrolysis of ions involving second order activation

  17. Elastin-like polypeptides: the power of design for smart cell encapsulation.

    Science.gov (United States)

    Bandiera, Antonella

    2017-01-01

    Cell encapsulation technology is still a challenging issue. Innovative methodologies such as additive manufacturing, and alternative bioprocesses, such as cell therapeutic delivery, where cell encapsulation is a key tool are rapidly gaining importance for their potential in regenerative medicine. Responsive materials such as elastin-based recombinant expression products have features that are particularly attractive for cell encapsulation. They can be designed and tailored to meet desired requirements. Thus, they represent promising candidates for the development of new concept-based materials that can be employed in this field. Areas covered: An overview of the design and employment of elastin-like polypeptides for cell encapsulation is given to outline the state of the art. Special attention is paid to the design of the macromolecule employed as well as to the method of matrix formation and the biological system involved. Expert opinion: As a result of recent progress in regenerative medicine there is a compelling need for materials that provide specific properties and demonstrate defined functional features. Rationally designed materials that may adapt according to applied external stimuli and that are responsive to biological systems, such as elastin-like polypeptides, belong to this class of smart material. A run through the components described to date represents a good starting point for further advancement in this area. Employment of these components in cell encapsulation application will promote its advance toward 'smart cell encapsulation technology'.

  18. Glucose-dependent insulinotropic polypeptide (GIP) receptor deletion leads to reduced bone strength and quality.

    Science.gov (United States)

    Mieczkowska, Aleksandra; Irwin, Nigel; Flatt, Peter R; Chappard, Daniel; Mabilleau, Guillaume

    2013-10-01

    Bone is permanently remodeled by a complex network of local, hormonal and neuronal factors that affect osteoclast and osteoblast biology. In this context, a role for gastro-intestinal hormones has been proposed based on evidence that bone resorption dramatically falls after a meal. Glucose-dependent insulinotropic polypeptide (GIP) is one of the candidate hormones as its receptor, glucose-dependent insulinotropic polypeptide receptor (GIPR), is expressed in bone. In the present study we investigated bone strength and quality by three-point bending, quantitative x-ray microradiography, microCT, qBEI and FTIR in a GIPR knockout (GIPR KO) mouse model and compared with control wild-type (WT) animals. Animals with a deletion of the GIPR presented with a significant reduction in ultimate load (--11%), stiffness (-16%), total absorbed (-28%) and post-yield energies (-27%) as compared with WT animals. Furthermore, despite no change in bone outer diameter, the bone marrow diameter was significantly increased and as a result cortical thickness was significantly decreased by 20% in GIPR deficient animals. Bone resorption at the endosteal surface was significantly increased whilst bone formation was unchanged in GIPR deficient animals. Deficient animals also presented with a pronounced reduction in the degree of mineralization of bone matrix. Furthermore, the amount of mature cross-links of collagen matrix was significantly reduced in GIPR deficient animals and was associated with lowered intrinsic material properties. Taken together, these data support a positive effect of the GIPR on bone strength and quality. © 2013.

  19. Utilization of membranes for H2O recycle system

    Science.gov (United States)

    Ohya, H.; Oguchi, M.

    1986-01-01

    Conceptual studies of closed ecological life support systems (CELSS) carried out at NAL in Japan for a water recycle system using membranes are reviewed. The system will treat water from shower room, urine, impure condensation from gas recycle system, and so on. The H2O recycle system is composed of prefilter, ultrafiltration membrane, reverse osmosis membrane, and distillator. Some results are shown for a bullet train of toilet-flushing water recycle equipment with an ultraviltration membrane module. The constant value of the permeation rate with a 4.7 square meters of module is about 70 1/h after 500th of operation. Thermovaporization with porous polytetrafluorocarbon membrane is also proposed to replce the distillator.

  20. D2-H2 equilibration over γ-irradiated zeolites

    International Nuclear Information System (INIS)

    Novakova, J.; Wichterlova, B.

    1987-01-01

    D 2 -H 2 equilibration was studied at 77 and 298 K over HY, AlHY, HZSM-5 and Alsub(x)Osub(y)HZSM-5 zeolites which had been γ-irradiated at 77 and/or 298 K. The exchange rate was found to be higher at the lower temperature regardless of the temperature of irradiation. Moreover, at 77 K the exchange rates were similar and more stable over the individual zeolites than at 298 K, thus indicating a common reaction path at 77 K. The exchange rate at 298 K depended on the zeolite type: it was more stable and higher over HZSM-5 than over HY, and extra-lattice Al increased both these properties on HY as well as on HZSM-5. The reaction mechanism is discussed in connection with the nature of defects generated by γ-irradiation. (author)

  1. Ultrafast Librational Relaxation of H2O in Liquid Water

    DEFF Research Database (Denmark)

    Petersen, Jakob; Møller, Klaus Braagaard; Rey, Rossend

    2013-01-01

    water molecules. The variation of the energy flow characteristics with rotational axis, initial rotational energy excitation magnitude, method of excitation, and temperature is discussed. Finally, the relation of the nonequilibrium results to equilibrium time correlations is investigated.......The ultrafast librational (hindered rotational) relaxation of a rotationally excited H2O molecule in pure liquid water is investigated by means of classical nonequilibrium molecular dynamics simulations and a power and work analysis. This analysis allows the mechanism of the energy transfer from...... hydration shell, dominated by those partners’ rotational motion, in a fairly symmetric fashion over the hydration shell. The minority component of the energy transfer, to these neighboring waters’ translational motion, exhibits an asymmetry in energy reception between hydrogen-bond-donating and -accepting...

  2. Does residual H2O2 result in inhibitory effect on enhanced anaerobic digestion of sludge pretreated by microwave-H2O2 pretreatment process?

    Science.gov (United States)

    Liu, Jibao; Jia, Ruilai; Wang, Yawei; Wei, Yuansong; Zhang, Junya; Wang, Rui; Cai, Xing

    2017-04-01

    This study investigated the effects of residual H 2 O 2 on hydrolysis-acidification and methanogenesis stages of anaerobic digestion after microwave-H 2 O 2 (MW-H 2 O 2 ) pretreatment of waste activated sludge (WAS). Results showed that high sludge solubilization at 35-45 % was achieved after pretreatment, while large amounts of residual H 2 O 2 remained and refractory compounds were thus generated with high dosage of H 2 O 2 (0.6 g H 2 O 2 /g total solids (TS), 1.0 g H 2 O 2 /g TS) pretreatment. The residual H 2 O 2 not only inhibited hydrolysis-acidification stage mildly, such as hydrolase activity, but also had acute toxic effect on methanogens, resulting in long lag phase, low methane yield rate, and no increase of cumulative methane production during the 30-day BMP tests. When the low dosage of H 2 O 2 at 0.2 g H 2 O 2 /g TS was used in MW-H 2 O 2 pretreatment, sludge anaerobic digestion was significantly enhanced. The cumulative methane production increased by 29.02 %, but still with a lag phase of 1.0 day. With removing the residual H 2 O 2 by catalase, the initial lag phase of hydrolysis-acidification stage decreased from 1.0 to 0.5 day.

  3. MLS/Aura Near-Real-Time L2 Water Vapor (H2O) Mixing Ratio V004 (ML2H2O_NRT) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2H2O_NRT is the EOS Aura Microwave Limb Sounder (MLS) Near-Real-Time (NRT) product for water vapor (H2O). This product contains H2O profiles derived from the 190...

  4. Evaluation of plasma H2S levels and H2S synthesis in streptozotocin induced Type-2 diabetes-an experimental study based on Swietenia macrophylla seeds

    Directory of Open Access Journals (Sweden)

    Moumita Dutta

    2014-05-01

    Conclusions: Although considering a small sample size, it can conclude that the fasting blood glucose levels are inversely related to plasma H2S levels as well as H2S synthesis activity in plasma and the extract of S. macrophylla is associated with increased plasma H2S levels with effective lowering of blood glucose in streptozotocin induced diabetic rats.

  5. An engineered coiled-coil polypeptide assembled onto quantum dots for targeted cell imaging

    Science.gov (United States)

    Yao, Ming-Hao; Yang, Jie; Song, Ji-Tao; Zhang, Lin; Fang, Bi-Yun; Zhao, Dong-Hui; Xia, Rui-Xue; Jin, Rui-Mei; Zhao, Yuan-Di; Liu, Bo

    2015-12-01

    Quantum dot (QD)-polypeptide probes have been developed through the specific metal-affinity interaction between polypeptides appended with N-terminal polyhistidine sequences and CdSe/ZnS core-shell QDs. The size and charge of a QD-polypeptide can be tuned by using different coiled-coil polypeptides. Compared to glutathione-capped QDs (QD-GSH), QD-polypeptide probes showed an approximately two- to three-fold luminescence increase, and the luminescence increase was not obviously related to the charge of the polypeptide. QD-polypeptide probes with different charge have a great effect on nonspecific cellular uptake. QD-polypeptide probes with negative charge exhibited lower nonspecific cellular uptake in comparison to the QD-GSH, while positively charged QD-polypeptide probes presented higher cellular uptake than the QD-GSH. A targeted QD-ARGD probe can obviously increase targeted cellular uptake in α v β 3 overexpressing HeLa cells compared to QD-A. In addition, QD-polypeptide probes showed lower in vitro cytotoxicity compared to the original QDs. These results demonstrate that these QD-polypeptide probes with high specific cellular uptake, high fluorescence intensity and low background noise are expected to have great potential applications in targeted cell imaging.

  6. Physical Properties of Pyridinium Fluorohydrogenate, [pyridine · H+][H2F3]-

    Science.gov (United States)

    Hulse, Ryan; Singh, Rajiv

    2008-12-01

    Ionic liquids (ILs), also referred to as molten salts, have found application as electrolytes for batteries and super-capacitors, in electroplating baths, as designer solvents, and as reaction media. A few of the desired properties of a super-capacitor electrolyte are nonflammability, thermal stability, and electrochemical stability. ILs containing aromatic cations have been shown to have low viscosity which results in a high electrochemical conductivity. There is a delicate balance between increasing the thermal stability, or decreasing the melting point, and increasing the electrochemical conductivity of the IL. This study focuses on pyridinium fluorohydrogenate, [pyridine · H+][H2F3]-. Pyridinium fluorohydrogenate has been synthesized by the reaction of pyridine and anhydrous hydrofluoric acid. This IL has a relatively high electrical conductivity (~98 mS · cm-1 at 23 °C), a wide electrochemical window, and a boiling point of 186 °C. A stable gel can also be formed by combining [pyridine · H+][H2F3]- and a super absorbent polymer such as polyacrylic acid. The gel adds mechanical stability to the matrix while not greatly affecting the conductivity of the IL.

  7. Nickel and platinum in high-temperature H2O + HCl fluids: Implications for hydrothermal mobilization

    Science.gov (United States)

    Scholten, Lea; Watenphul, Anke; Beermann, Oliver; Testemale, Denis; Ames, Doreen; Schmidt, Christian

    2018-03-01

    The dissolution of NiS and NiAs (nickeline) in 0.1 and 1 molal HCl at 400 °C, 80 MPa, and of PtAs2 (sperrylite) and Pt metal in 1 and 6.86 molal HCl at 500 °C, 80 MPa was studied in-situ using synchrotron radiation X-ray fluorescence and absorption spectroscopy. The Pt concentration in the fluid averaged 8 · 10-5 molal (12.8 ppm) during dissolution of Pt metal in 6.86 molal HCl, and was below the minimum detection limit (mdl; 2.6 · 10-5 molal) in all other experiments. Dissolution of NiS was congruent or nearly congruent. Equilibrium was attained rapidly in about 250 min at an initial HCl concentration of 1 molal HCl, and in about 500 min at 0.1 molal HCl. Addition of HCl resulted in a large increase in the Ni solubility from 7.2 · 10-3 molal Ni (423 ppm) at 0.1 molal HCl to 8.72 · 10-2 molal Ni (4959 ppm) at 1 molal HCl. Dissolution of NiAs in 0.1 and 1 molal HCl was incongruent. A steady state was not reached even at a run duration of more than 16 h, and the maximum recorded Ni concentrations in the fluid were much lower than the Ni solubility in the corresponding experiments with NiS at the same HCl molality. Measured K-edge XANES spectra in comparison with literature data indicated that arsenic in the fluid was present as As(V) and that nickel complexed with Cl and H2O as tetrahedral [NiCl2(H2O)2]0 and [NiCl3(H2O)]- and octahedral [NiCl2(H2O)4]0 species. In addition, Raman spectra of H2O + NiCl2 and H2O + NiCl2 + HCl solutions and of H2O + HCl fluids reacted with NiS crystals were acquired at temperatures (T) up to 600 °C and pressures (P) up to 1.15 GPa. All spectra at T ≥ 300 °C and P Based on calculated vibrational frequencies available in the literature, it may stem from the species [NiCl4]2- or [NiCl2(H2O)4]0, although particularly the first assignment is in conflict with the information from published XAS data. The results of this study demonstrate that nickel is readily mobilized by acidic chloridic hydrothermal fluids, but platinum remains

  8. Catalase activity is stimulated by H2O2 in rich culture medium and is required for H2O2 resistance and adaptation in yeast ☆

    OpenAIRE

    Martins, Dorival; English, Ann M.

    2014-01-01

    Catalases are efficient scavengers of H2O2 and protect cells against H2O2 stress. Examination of the H2O2 stimulon in Saccharomyces cerevisiae revealed that the cytosolic catalase T (Ctt1) protein level increases 15-fold on H2O2 challenge in synthetic complete media although previous work revealed that deletion of the CCT1 or CTA1 genes (encoding peroxisomal/mitochondrial catalase A) does not increase the H2O2 sensitivity of yeast challenged in phosphate buffer (pH 7.4). This we attributed to...

  9. High molecular weight polypeptide bands specific for equine herpesvirus 4.

    Science.gov (United States)

    Zheng, M; Love, D N; Sabine, M

    1995-09-01

    Serum neutralisation (SN) and immunoblotting were used in attempts to distinguish between natural infections with the closely related viruses equine herpesvirus 1 (EHV-1) and equine herpes-virus 4 (EHV-4). Horse sera (n = 323) collected in 1990 from studs with no experience of EHV-1 abortions as well as 197 sera collected in 1992 from studs with a history of EHV-1 abortions were tested by SN. The two groups differed in the proportion with measurable EHV-1 antibody, the 1992 group being significantly higher. Both groups had high proportions with EHV-4 antibody and no serum had antibody to EHV-1 alone. Pools of positive sera were prepared as probes in immunoblots. High molecular weight (> 200 kDa) polypeptide bands specific for EHV-4 were detected. No bands specific for EHV-1 only were found. The specific EHV-4 polypeptides shared some properties with gp2 of EHV-1.

  10. Compositions and methods for making selenocysteine containing polypeptides

    Energy Technology Data Exchange (ETDEWEB)

    Soll, Dieter; Aldag, Caroline; Hohn, Michael

    2016-10-11

    Non-naturally occurring tRNA.sup.Sec and methods of using them for recombinant expression of proteins engineered to include one or more selenocysteine residues are disclosed. The non-naturally occurring tRNA.sup.Sec can be used for recombinant manufacture of selenocysteine containing polypeptides encoded by mRNA without the requirement of an SECIS element. In some embodiments, selenocysteine containing polypeptides are manufactured by co-expressing a non-naturally occurring tRNA.sup.Sec a recombinant expression system, such as E. coli, with SerRS, EF-Tu, SelA, or PSTK and SepSecS, and an mRNA with at least one codon that recognizes the anticodon of the non-naturally occurring tRNA.sup.Sec.

  11. Imparting large macroscopic changes with small changes in polypeptide composition

    Science.gov (United States)

    Sing, Michelle; McKinley, Gareth; Olsen, Bradley

    Block copolymers composed of polypeptides provide an excellent platform for exploring the underlying physics surrounding macroscopic associative network behavior. Previous work in our group has elucidated a difference in the mechanical properties of two nearly identical elastin-like polypeptide (ELP) endblocks. In poly(ELP)s, this substitution is known to result in tighter beta turns. These beta turns exhibit slower responses to changes in temperature within the material. Under shear, the modulus for the alanine-containing ELP triblock is almost three times higher than the glycine-containing ELP. Additionally, preliminary tensile tests show higher stress and strain at break for the alanine ELP triblock. We are able to explain the reasons for this behavior using a variety of spectroscopic and analytical techniques. Small angle neutron and x-ray scattering indicate differences in ordering between the alanine and glycine containing ELP materials both in shear and in stagnant flow.

  12. NMR study of the cooperative behavior of thermotropic model polypeptides

    Czech Academy of Sciences Publication Activity Database

    Kurková, Dana; Kříž, Jaroslav; Rodríguez-Cabello, J. C.; Arias, F. J.

    2007-01-01

    Roč. 56, č. 2 (2007), s. 186-194 ISSN 0959-8103 R&D Projects: GA AV ČR IAA400500604 Grant - others:Spanish Ministry of Science and Culture (ES) A002/02; MAT2000-1764-C02; MAT2001-1853-C02-01; MAT2003- Institutional research plan: CEZ:AV0Z40500505 Keywords : thermotropic polymers * cooperativity * synthetic polypeptides Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.557, year: 2007

  13. 26 CFR 1.642(h)-2 - Excess deductions on termination of an estate or trust.

    Science.gov (United States)

    2010-04-01

    ... trust. 1.642(h)-2 Section 1.642(h)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Estates, Trusts, and Beneficiaries § 1.642(h)-2...)) in excess of gross income, the excess is allowed under section 642(h)(2) as a deduction to the...

  14. The histone variant macroH2A is an epigenetic regulator of key developmental genes

    DEFF Research Database (Denmark)

    Buschbeck, Marcus; Uribesalgo, Iris; Wibowo, Indra

    2009-01-01

    The histone variants macroH2A1 and macroH2A2 are associated with X chromosome inactivation in female mammals. However, the physiological function of macroH2A proteins on autosomes is poorly understood. Microarray-based analysis in human male pluripotent cells uncovered occupancy of both macroH2A ...

  15. Putrescine protects hulless barley from damage due to UV-B stress via H2S- and H2O2-mediated signaling pathways.

    Science.gov (United States)

    Li, Qien; Wang, Zhaofeng; Zhao, Yanning; Zhang, Xiaochen; Zhang, Shuaijun; Bo, Letao; Wang, Yao; Ding, Yingfeng; An, Lizhe

    2016-05-01

    In hulless barley, H 2 S mediated increases in H 2 O 2 induced by putrescine, and their interaction enhanced tolerance to UV-B by maintaining redox homeostasis and promoting the accumulation of UV-absorbing compounds. This study investigated the possible relationship between putrescence (Put), hydrogen sulfide (H2S) and hydrogen peroxide (H2O2) as well as the underlying mechanism of their interaction in reducing UV-B induced damage. UV-B radiation increased electrolyte leakage (EL) and the levels of malondialdehyde (MDA) and UV-absorbing compounds but reduced antioxidant enzyme activities and glutathione (GSH) and ascorbic acid (AsA) contents. Exogenous application of Put, H2S or H2O2 reduced some of the above-mentioned negative effects, but were enhanced by the addition of Put, H2S and H2O2 inhibitors. Moreover, the protective effect of Put against UV-B radiation-induced damage to hulless barley was diminished by DL-propargylglycine (PAG, a H2S biosynthesis inhibitor), hydroxylamine (HT, a H2S scavenger), diphenylene iodonium (DPI, a PM-NADPH oxidase inhibitor) and dimethylthiourea (DMTU, a ROS scavenger), and the effect of Put on H2O2 accumulation was abolished by HT. Taken together, as the downstream component of the Put signaling pathway, H2S mediated H2O2 accumulation, and H2O2 induced the accumulation of UV-absorbing compounds and maintained redox homeostasis under UV-B stress, thereby increasing the tolerance of hulless barley seedlings to UV-B stress.

  16. Generation of polypeptide-templated gold nanoparticles using ionizing radiation.

    Science.gov (United States)

    Walker, Candace Rae; Pushpavanam, Karthik; Nair, Divya Geetha; Potta, Thrimoorthy; Sutiyoso, Caesario; Kodibagkar, Vikram D; Sapareto, Stephen; Chang, John; Rege, Kaushal

    2013-08-13

    Ionizing radiation, including γ rays and X-rays, are high-energy electromagnetic radiation with diverse applications in nuclear energy, astrophysics, and medicine. In this work, we describe the use of ionizing radiation and cysteine-containing elastin-like polypeptides (C(n)ELPs, where n = 2 or 12 cysteines in the polypeptide sequence) for the generation of gold nanoparticles. In the presence of C(n)ELPs, ionizing radiation doses higher than 175 Gy resulted in the formation of maroon-colored gold nanoparticle dispersions, with maximal absorbance at 520 nm, from colorless metal salts. Visible color changes were not observed in any of the control systems, indicating that ionizing radiation, gold salt solution, and C(n)ELPs were all required for nanoparticle formation. The hydrodynamic diameters of nanoparticles, determined using dynamic light scattering, were in the range of 80-150 nm, while TEM imaging indicated the formation of gold cores 10-20 nm in diameter. Interestingly, C2ELPs formed 1-2 nm diameter gold nanoparticles in the absence of radiation. Our results describe a facile method of nanoparticle formation in which nanoparticle size can be tailored based on radiation dose and C(n)ELP type. Further improvements in these polypeptide-based systems can lead to colorimetric detection of ionizing radiation in a variety of applications.

  17. Separation and nanoencapsulation of antitumor polypeptide from Spirulina platensis.

    Science.gov (United States)

    Zhang, Bochao; Zhang, Xuewu

    2013-01-01

    Spirulina platensis is a multicellular edible blue-green alga with abundant proteins (∼ 60%). No report is available on the antitumor polypeptides from the whole proteins of S. platensis. In this study, for the first time, an antitumor polypeptide Y2 from trypsin digest of S. platensis proteins was obtained by using freeze-thawing plus ultrasonication extraction, hydrolysis with four enzymes (trypsin, alcalase, papain, and pepsin), and gel filtration chromatography. The results showed that the degree of hydrolysis can be ordered as: trypsin (38.5%) > alcalase (31.2%) > papain (27.8%) > pepsin (7.1%). For MCF-7 and HepG2 cells, at 250 µg/mL, the maximum inhibitory rate of Y2 was 97%, while standard drug 5-FU was 55 and 97%, respectively. Furthermore, the nanoencapsulation of Y2 with chitosan (CS) was also investigated. After nanoencapsulation, the maximum encapsulation efficiency and polypeptides contents are 49 and 15%, respectively; and the antitumor activity is basically not lost. These data demonstrated the potential of nanopolypeptides (Y2-CS) in food and pharmaceutical applications. © 2013 American Institute of Chemical Engineers.

  18. Short-range interaction energy for ground state H2+

    Science.gov (United States)

    Battezzati, Michele; Magnasco, Valerio

    2006-12-01

    Two of the Hermitian eigenvalue equations resulting from the separation of the three-dimensional Schroedinger equation for H2+ in spheroidals are solved perturbatively for the ground state by expanding the action in positive powers of the internuclear distance R near the united atom He+. The dispersion relations between the separation constants A and Ee are seen to have rigorous analytic solutions, the third-order equation leading to an exact expansion for the inner determinantal equation up to R10. The explicit form for the expansion coefficients is determined up to n = 10, and is seen to contain up to the third power of (γ + ln 4R) logarithmic terms. Even if the general range of validity of the short-range Rn-expansion is expected to be smaller than the corresponding long-range R-n-expansion, it is important to stress that such higher expansion coefficients are calculated exactly for the first time. These formulae give extremely accurate numerical results up to R cong 0.3a0.

  19. Interpretation of the H2O maser outbursts in Orion

    International Nuclear Information System (INIS)

    Strel'nitskij, V.S.

    1982-01-01

    It is shown, that the H 2 O maser that flared up in Orion (+8 km/s) was partly unsaturated. The anti-correlation between the line width and intensity, the asymmetry of the profile and the changes of the visibility function within it are explained by blending of two componenets, one of which has experienced a flare. From the observed polarization properties the upper limit to the electron density (nsub(e) 5 cm -3 ), the strength of the magnetic field (B approximately 10 -2 G) and its direction (position angle phi approximately -15 deg) within the source are deduced. According to the proposed physical model the source is a gas condensation, pressed, heated and accelerated by the strong stellar wind from a young star (possibly IRc4). The maser is pumped by the CCr-process at sup(n)H approximately 10 11 -10 12 cm -3 . If the condensation is a remnant of a circumstellar gas-dust disk, the magnetic field within the disk must be essentially azimuthal [ru

  20. An Accurate Potential Energy Surface for H2O

    Science.gov (United States)

    Schwenke, David W.; Partridge, Harry; Langhoff, Stephen R. (Technical Monitor)

    1997-01-01

    We have carried out extensive high quality ab initio electronic structure calculations of the ground state potential energy surface (PES) and dipole moment function (DMF) for H2O. A small adjustment is made to the PES to improve the agreement of line positions from theory and experiment. The theoretical line positions are obtained from variational ro-vibrational calculations using the exact kinetic energy operator. For the lines being fitted, the root-mean-square error was reduced from 6.9 to 0.08 /cm. We were then able to match 30,092 of the 30,117 lines from the HITRAN 96 data base to theoretical lines, and 80% of the line positions differed less than 0.1 /cm. About 3% of the line positions in the experimental data base appear to be incorrect. Theory predicts the existence of many additional weak lines with intensities above the cutoff used in the data base. To obtain results of similar accuracy for HDO, a mass dependent correction to the PH is introduced and is parameterized by simultaneously fitting line positions for HDO and D2O. The mass dependent PH has good predictive value for T2O and HTO. Nonadiabatic effects are not explicitly included. Line strengths for vibrational bands summed over rotational levels usually agree well between theory and experiment, but individual line strengths can differ greatly. A high temperature line list containing about 380 million lines has been generated using the present PES and DMF

  1. Ionization of H2(+) in intense laser fields

    Science.gov (United States)

    Mies, F. H.; Giusti-Suzor, A.; Kulander, K. C.; Schafer, K. J.

    1993-01-01

    The motivation for the present ionization calculations is to test the reliability of a recent study of H2(+) photodissociation which employed such a two electronic state model and neglected any competition with ionization. The photodissociation calculations indicate that in intense short pulsed laser fields appreciable populations of stable vibrational states can survive the pulse. This survival effect can be attributed to the trapping of portions of the initial vibrational wavepacket in transient laser-induced potential wells at intermediate R approximately 3-4 au distances. Since the calculated ionization rates exhibit a marked decrease at short R, they already lend some credence to the vibrational trapping effect. Having accurate R-dependent rates enables us to estimate the competitive influence of the ionization on the stabilized population, and may ultimately allow us to predict the contribution of the Coulomb 'explosion' channel to observed proton kinetic energy distributions. In this paper we will demonstrate the effectiveness of the two-state length gauge model in interpreting the ionization rates that we extract from the numerically exact solutions of the time-dependent Schroedinger equation. A more elaborate presentation of the theory and the results for the full range of distances and wavelengths will be presented elsewhere.

  2. Solid-state photoelectrochemical H2 generation with gaseous reactants

    International Nuclear Information System (INIS)

    Iwu, Kingsley O.; Galeckas, Augustinas; Kuznetsov, Andrej Yu.; Norby, Truls

    2013-01-01

    Photocurrent and H 2 production were demonstrated in an all solid-state photoelectrochemical cell employing gaseous methanol and water vapour at the photoanode. Open circuit photovoltage of around −0.4 V and short circuit photocurrent of up to 250 μA/cm 2 were obtained. At positive bias, photocurrent generation was limited by the irradiance, i.e., the amount of photogenerated charge carriers at the anode. Time constants and impedance spectra showed an electrochemical capacitance of the cell of about 15 μF/cm 2 in the dark, which increased with increasing irradiance. With only water vapour at the anode, the short circuit photocurrent was about 6% of the value with gaseous methanol and water vapour. The photoanode and electrocatalyst on carbon paper support were affixed to the proton conducting membrane using Nafion ® as adhesive, an approach that yielded photocurrents up to 15 times better than that of a cell assembled by hot-pressing, in spite of the overall cell resistance of the latter being up to five times less than that of the former. This is attributed, at least partially, to reactants being more readily available at the photoanode of the better performing cell

  3. Nonlocal effects in dissociative electron attachment to H2

    International Nuclear Information System (INIS)

    Atems, D.E.; Wadehra, J.M.

    1990-01-01

    Electron scattering by diatomic molecules involving the formation of a single resonance is treated within the configuration-interaction formalism. A technique is presented for solving the resulting nonlocal integro-differential equation for the nuclear motion in the resonant state. This technique is applied to the scattering of electrons by molecular hydrogen (and its isotopes) via the formation of X 2 Σ u + resonance, using a semiempirical model for the resonant state. Numerical cross sections for dissociative attachment, to H 2 , of electrons with energies below 5 eV are presented and compared both with available experimental data and with those obtained using the local approximation for the complete integro-differential equation. In contrast to the local theory, the nonlocal theory predicts cross sections that exhibit discontinuities at energies at which a new vibrational channel opens up. We also give an upper bound for attachment cross sections that holds for all isotopes of molecular hydrogen for all values of the incident electron energies

  4. PowerPoint Presentation

    Indian Academy of Sciences (India)

    PowerPoint Presentation · Slide 2 · Slide 3 · Getting Smart with Smart Windows! Slide 5 · Energy Crisis!! Total World Primary Energy Supply · “We Ride on Water!” Volume for storage of 4 kg H2 in different states · Slide 10 · Linkers make a Difference! Coordination Polymers · Principle Behind Formation of MOFs · Slide 14.

  5. Implications of the (H2O)n + CO ↔ trans-HCOOH + (H2O)n-1 (n = 1, 2, and 3) reactions for primordial atmospheres of Venus and Earth

    Science.gov (United States)

    Vichietti, R. M.; Spada, R. F. K.; da Silva, A. B. F.; Machado, F. B. C.; Haiduke, R. L. A.

    2018-04-01

    The forward and backward (H2O)n + CO ↔ HCOOH + (H2O)n-1 (n = 1, 2, and 3) reactions were studied in order to furnish trustworthy thermochemical and kinetic data. Stationary point structures involved in these chemical processes were achieved at the B2PLYP/cc-pVTZ level so that the corresponding vibrational frequencies, zero-point energies, and thermal corrections were scaled to consider anharmonicity effects. A complete basis set extrapolation was also employed with the CCSD(T) method in order to improve electronic energy descriptions and providing therefore more accurate results for enthalpies, Gibbs energies, and rate constants. Forward and backward rate constants were encountered at the high-pressure limit between 200 and 4000 K. In turn, modified Arrhenius' equations were fitted from these rate constants (between 700 and 4000 K). Next, considering physical and chemical conditions that have supposedly prevailed on primitive atmospheres of Venus and Earth, our main results indicate that 85-88 per cent of all water forms on these atmospheres were monomers, whereas (H2O)2 and (H2O)3 complexes would represent 12-15 and ˜0 per cent, respectively. Besides, we estimate that Earth's and Venus' primitive atmospheres could have been composed by ˜0.001-0.003 per cent of HCOOH when their temperatures were around 1000-2000 K. Finally, the water loss process on Venus may have occurred by a mechanism that includes the formic acid as intermediate species.

  6. The impact of atmospheric H2S on growth and sulfur metabolism of Allium cepa L.

    NARCIS (Netherlands)

    Durenkamp, M; De Kok, LJ

    2002-01-01

    The impact of atmospheric H2S deposition on growth and sulfur metabolism has been studied in onion (Allium cepa L.). The H2S Uptake followed saturation kinetics with respect to the H2S concentration. The maximum H2S uptake rate (JH(2)S(max)) was approx. 1 mumol g(-1) FW h(-1) and the KH2S (H2S

  7. Solubility Modeling of the Binary Systems Fe(NO3)3–H2O, Co(NO3)2–H2O and the Ternary System Fe(NO3)3–Co(NO3)2–H2O with the Extended Universal Quasichemical (UNIQUAC) Model

    DEFF Research Database (Denmark)

    Arrad, Mouad; Kaddami, Mohammed; Goundali, Bahija El

    2016-01-01

    Solubility modeling in the binary system Fe(NO3)3–H2O, Co(NO3)2–H2O and the ternary system Fe(NO3)3–Co(NO3)2–H2O is presented. The extended UNIQUAC model was applied to the thermodynamic assessment of the investigated systems. The model parameters obtained were regressed simultaneously using...... the available databank but with more experimental points, recently published in the open literature. A revision of previously published parameters for the cobalt ion and new parameters for the iron(III) nitrate system are presented. Based on this set of parameters, the equilibrium constants of hydrates...

  8. Influence of Aluminium and EGCG on Fibrillation and Aggregation of Human Islet Amyloid Polypeptide

    Directory of Open Access Journals (Sweden)

    Zhi-Xue Xu

    2016-01-01

    Full Text Available The abnormal fibrillation of human islet amyloid polypeptide (hIAPP has been implicated in the development of type II diabetes. Aluminum is known to trigger the structural transformation of many amyloid proteins and induce the formation of toxic aggregate species. The (−-epigallocatechin gallate (EGCG is considered capable of binding both metal ions and amyloid proteins with inhibitory effect on the fibrillation of amyloid proteins. However, the effect of Al(III/EGCG complex on hIAPP fibrillation is unclear. In the present work, we sought to view insight into the structures and properties of Al(III and EGCG complex by using spectroscopic experiments and quantum chemical calculations and also investigated the influence of Al(III and EGCG on hIAPP fibrillation and aggregation as well as their combined interference on this process. Our studies demonstrated that Al(III could promote fibrillation and aggregation of hIAPP, while EGCG could inhibit the fibrillation of hIAPP and lead to the formation of hIAPP amorphous aggregates instead of the ordered fibrils. Furthermore, we proved that the Al(III/EGCG complex in molar ratio of 1 : 1 as Al(EGCG(H2O2 could inhibit the hIAPP fibrillation more effectively than EGCG alone. The results provide the invaluable reference for the new drug development to treat type II diabetes.

  9. Origin of CH+ in diffuse molecular clouds. Warm H2 and ion-neutral drift

    Science.gov (United States)

    Valdivia, Valeska; Godard, Benjamin; Hennebelle, Patrick; Gerin, Maryvonne; Lesaffre, Pierre; Le Bourlot, Jacques

    2017-04-01

    abundances of CH+. Compared to previous works, our multiphase simulations reduce the spread in vd, and our self-consistent treatment of the ionisation leads to much reduced vd. Nevertheless, our resolution study shows that this velocity distribution is not converged: the ion-neutral drift has a higher impact on CH+ at higher resolution. On the other hand, our ideal MHD simulations do not include ambipolar diffusion, which would yield lower drift velocities. Conclusions: Within these limitations, we conclude that warm H2 is a key ingredient in the efficient formation of CH+ and that the ambipolar diffusion has very little influence on the abundance of CH+, mainly due to the small drift velocities obtained. However, we point out that small-scale processes and other non-thermal processes not included in our MHD simulation may be of crucial importance, and higher resolution studies with better controlled dissipation processes are needed.

  10. Promotion of H2 production by microwave-assisted treatment of water hyacinth with dilute H2SO4 through combined dark fermentation and photofermentation

    International Nuclear Information System (INIS)

    Cheng, Jun; Xia, Ao; Su, Huibo; Song, Wenlu; Zhou, Junhu; Cen, Kefa

    2013-01-01

    Highlights: • Water hyacinth is microwaved with dilute H 2 SO 4 to improve enzymatic hydrolysis. • Hydrolyzed hyacinth is fermented by hydrogenogens to improve dark H 2 yield. • Nearly 100% glucose and most arabinose in hydrolysate are used in dark fermentation. • H 2 yield from hyacinth via combined fermentation is 75.2% of theoretical H 2 yield. - Abstract: Water hyacinth was treated with microwave-assisted dilute H 2 SO 4 to improve saccharification before enzymatic hydrolysis and H 2 production during dark fermentation. A maximum reducing sugar (RS) yield of 64.4 g/100 g total volatile solid (TVS) (96.1% of the theoretical RS yield) was achieved when water hyacinth was treated through microwave heating with 1% dilute H 2 SO 4 for 15 min at 140 °C and then enzymatically hydrolyzed for 72 h. During enzymatic hydrolysis, glucose was efficiently produced from the hydrolysis of cellulose that resulted from the disruption of the lignocellulosic structure of water hyacinth after microwave-assisted H 2 SO 4 treatment. When the hydrolyzed water hyacinth was inoculated with H 2 -producing bacteria to produce H 2 during dark fermentation, a maximum H 2 yield of 112.3 ml/g TVS was obtained. The major sugar compositions in the residual solution from dark fermentation were xylose and cellobiose (total RS utilization efficiency: 88.5%). Through a combination of dark fermentation and photofermentation, the maximum H 2 yield from water hyacinth was significantly increased from 112.3 ml/g TVS to 751.5 ml/g TVS, which is 75.2% of the theoretical H 2 yield

  11. Catalase activity is stimulated by H2O2 in rich culture medium and is required for H2O2 resistance and adaptation in yeast

    Directory of Open Access Journals (Sweden)

    Dorival Martins

    2014-01-01

    Full Text Available Catalases are efficient scavengers of H2O2 and protect cells against H2O2 stress. Examination of the H2O2 stimulon in Saccharomyces cerevisiae revealed that the cytosolic catalase T (Ctt1 protein level increases 15-fold on H2O2 challenge in synthetic complete media although previous work revealed that deletion of the CCT1 or CTA1 genes (encoding peroxisomal/mitochondrial catalase A does not increase the H2O2 sensitivity of yeast challenged in phosphate buffer (pH 7.4. This we attributed to our observation that catalase activity is depressed when yeast are challenged with H2O2 in nutrient-poor media. Hence, we performed a systematic comparison of catalase activity and cell viability of wild-type yeast and of the single catalase knockouts, ctt1∆ and cta1∆, following H2O2 challenge in nutrient-rich medium (YPD and in phosphate buffer (pH 7.4. Ctt1 but not Cta1 activity is strongly induced by H2O2 when cells are challenged in YPD but suppressed when cells are challenged in buffer. Consistent with the activity results, exponentially growing ctt1∆ cells in YPD are more sensitive to H2O2 than wild-type or cta1∆ cells, whereas in buffer all three strains exhibit comparable H2O2 hypersensitivity. Furthermore, catalase activity is increased during adaptation to sublethal H2O2 concentrations in YPD but not in buffer. We conclude that induction of cytosolic Ctt1 activity is vital in protecting yeast against exogenous H2O2 but this activity is inhibited by H2O2 when cells are challenged in nutrient-free media.

  12. Catalase activity is stimulated by H2O2 in rich culture medium and is required for H2O2 resistance and adaptation in yeast☆

    Science.gov (United States)

    Martins, Dorival; English, Ann M.

    2014-01-01

    Catalases are efficient scavengers of H2O2 and protect cells against H2O2 stress. Examination of the H2O2 stimulon in Saccharomyces cerevisiae revealed that the cytosolic catalase T (Ctt1) protein level increases 15-fold on H2O2 challenge in synthetic complete media although previous work revealed that deletion of the CCT1 or CTA1 genes (encoding peroxisomal/mitochondrial catalase A) does not increase the H2O2 sensitivity of yeast challenged in phosphate buffer (pH 7.4). This we attributed to our observation that catalase activity is depressed when yeast are challenged with H2O2 in nutrient-poor media. Hence, we performed a systematic comparison of catalase activity and cell viability of wild-type yeast and of the single catalase knockouts, ctt1∆ and cta1∆, following H2O2 challenge in nutrient-rich medium (YPD) and in phosphate buffer (pH 7.4). Ctt1 but not Cta1 activity is strongly induced by H2O2 when cells are challenged in YPD but suppressed when cells are challenged in buffer. Consistent with the activity results, exponentially growing ctt1∆ cells in YPD are more sensitive to H2O2 than wild-type or cta1∆ cells, whereas in buffer all three strains exhibit comparable H2O2 hypersensitivity. Furthermore, catalase activity is increased during adaptation to sublethal H2O2 concentrations in YPD but not in buffer. We conclude that induction of cytosolic Ctt1 activity is vital in protecting yeast against exogenous H2O2 but this activity is inhibited by H2O2 when cells are challenged in nutrient-free media. PMID:24563848

  13. Catalase activity is stimulated by H(2)O(2) in rich culture medium and is required for H(2)O(2) resistance and adaptation in yeast.

    Science.gov (United States)

    Martins, Dorival; English, Ann M

    2014-01-01

    Catalases are efficient scavengers of H2O2 and protect cells against H2O2 stress. Examination of the H2O2 stimulon in Saccharomyces cerevisiae revealed that the cytosolic catalase T (Ctt1) protein level increases 15-fold on H2O2 challenge in synthetic complete media although previous work revealed that deletion of the CCT1 or CTA1 genes (encoding peroxisomal/mitochondrial catalase A) does not increase the H2O2 sensitivity of yeast challenged in phosphate buffer (pH 7.4). This we attributed to our observation that catalase activity is depressed when yeast are challenged with H2O2 in nutrient-poor media. Hence, we performed a systematic comparison of catalase activity and cell viability of wild-type yeast and of the single catalase knockouts, ctt1∆ and cta1∆, following H2O2 challenge in nutrient-rich medium (YPD) and in phosphate buffer (pH 7.4). Ctt1 but not Cta1 activity is strongly induced by H2O2 when cells are challenged in YPD but suppressed when cells are challenged in buffer. Consistent with the activity results, exponentially growing ctt1∆ cells in YPD are more sensitive to H2O2 than wild-type or cta1∆ cells, whereas in buffer all three strains exhibit comparable H2O2 hypersensitivity. Furthermore, catalase activity is increased during adaptation to sublethal H2O2 concentrations in YPD but not in buffer. We conclude that induction of cytosolic Ctt1 activity is vital in protecting yeast against exogenous H2O2 but this activity is inhibited by H2O2 when cells are challenged in nutrient-free media.

  14. Elastin-like polypeptides and their applications in anticancer drug delivery systems: a review.

    Science.gov (United States)

    Saxena, Rubha; Nanjan, Moola Joghee

    2015-02-01

    Elastin-like polypeptides (ELPs) are large molecular weight biopolymers. They have been widely studied as macromolecular carriers for targeted delivery of drugs. The aim of the present article is to review the available information on ELPs (including our recent investigations), their properties, drug delivery applications to tumor sites and future perspectives. This review also provides information on the use of short synthetic ELPs for making ELP-drug conjugates, for targeted delivery of anticancer drugs. In the present review we also focus on the point that short ELPs can also be used for targeting anticancer drugs to tumor sites as they behave similar to long ELPs regarding their capacity to undergo inverse temperature transition (ITT) behavior.

  15. Molecular simulation of CH4/CO2/H2O competitive adsorption on low rank coal vitrinite.

    Science.gov (United States)

    Yu, Song; Bo, Jiang; Wu, Li

    2017-07-21

    The competitive adsorptions of CH 4 /CO 2 /H 2 O on coal vitrinite (DV-8, C 214 H 180 O 24 N 2 ) were computed based on density function theory (DFT) and grand canonical Monte Carlo (GCMC). The adsorption process reaches the saturation state after adsorbing 17 CH 4 s, 22 CO 2 s, and 35 H 2 Os per C 214 H 180 O 24 N 2 respectively. The optimal configurations of CH 4 -vitrinite, CO 2 -vitrinite, and H 2 O-vitrinite respectively manifest as aromatic 1 /T 2 /rT 3 (1 adsorption location, 2 adsorption sites and T here represents sites above the carbon atom and the heteroatom, 3 adsorption orientation and rT here means the orientations of three hydrogen atoms pointing to vitrinite), aromatic/T/v (v represents the orientations perpendicular to the plane of vitrinite), and aromatic/rV/T (rV represents an oxygen atom pointing to the vitrinite surface). The GCMC results show that high temperature is not conducive to the vitrinite's adsorption of adsorbates and the adsorption capacity order is H 2 O > CO 2 > CH 4 (263-363 K) in the one-component, binary, and ternary adsorbate systems. The optimal configurations of vitrinite are similar to graphite/graphene, while ΔE is significantly lower than graphite/graphene. Simulation data are in good agreement with the experimental results.

  16. HDO/H2O ratio retrievals from GOSAT

    Directory of Open Access Journals (Sweden)

    H. Boesch

    2013-03-01

    Full Text Available We report a new shortwave infrared (SWIR retrieval of the column-averaged HDO/H2O ratio from the Japanese Greenhouse Gases Observing Satellite (GOSAT. From synthetic simulation studies, we have estimated that the inferred δD values will typically have random errors between 20‰ (desert surface and 30° solar zenith angle and 120‰ (conifer surface and 60° solar zenith angle. We find that the retrieval will have a small but significant sensitivity to the presence of cirrus clouds, the HDO a priori profile shape and atmospheric temperature, which has the potential of introducing some regional-scale biases in the retrieval. From comparisons to ground-based column observations from the Total Carbon Column Observing Network (TCCON, we find differences between δD from GOSAT and TCCON of around −30‰ for northern hemispheric sites which increase up to −70‰ for Australian sites. The bias for the Australian sites significantly reduces when decreasing the spatial co-location criteria, which shows that spatial averaging contributes to the observed differences over Australia. The GOSAT retrievals allow mapping the global distribution of δD and its variations with season, and we find in our global GOSAT retrievals the expected strong latitudinal gradients with significant enhancements over the tropics. The comparisons to the ground-based TCCON network and the results of the global retrieval are very encouraging, and they show that δD retrieved from GOSAT should be a useful product that can be used to complement datasets from thermal-infrared sounder and ground-based networks and to extend the δD dataset from SWIR retrievals established from the recently ended SCIAMACHY mission.

  17. Antibodies to H2a and H2b histones from the sera of HIV-infected patients catalyze site-specific degradation of these histones.

    Science.gov (United States)

    Baranova, Svetlana V; Dmitrienok, Pavel S; Ivanisenko, Nikita V; Buneva, Valentina N; Nevinsky, Georgy A

    2017-06-01

    Histones and their post-translational modifications have key roles in chromatin remodeling and gene transcription. Besides intranuclear functions, histones act as damage-associated molecules when they are released into the extracellular space. Administration of histones to animals leads to systemic inflammatory and toxic responses. Autoantibodies with enzymatic activities (abzymes) are distinctive features of some autoimmune and viral diseases. Electrophoretically homogeneous IgGs containing no canonical enzymes were isolated from the sera of HIV-infected patients by chromatography on several affinity sorbents including anti-histone Sepharose. In contrast to canonical proteases (trypsin, chymotrypsin, proteinase K), IgGs from HIV-infected patients specifically hydrolyzed only histones but not many other tested globular proteins. Using MALDI mass spectrometry the sites of H2a and H2b histone cleavage by anti-histone IgGs were determined for the first time. One cluster of H2a hydrolysis contains two major (↕) and four moderate (↓) cleavage sites: 31-H↓R↓L↓L↓R↕K G↕N-38. One major and two moderate sites of cleavage were revealed in the second cluster: 14-A↕KSRS↓SRA↓G-22. The third cluster corresponding to the H2a C-terminal part contains only five minor (†) sites of cleavage: 82-H†LQLAIRNDEELN†KLLG†RV†T†I-102. It was shown that two major and four moderate sites of cleavage were present in the main cluster of H2b hydrolysis: 46-K↕QvhpD↓TgiS↓SkA↓M↕GiM↓N-63. Two moderate sites of cleavage correspond to a relatively short 6-mer cluster: 12-K↓GskK↓A-17. The third relatively long 9-mer cluster contains one major and two minor sites of H2b cleavage: 80-L↕AHYN†KRS†T-88. In the nucleosome core particle, most of the major and moderate cleavage sites are located at the H2a/H2b interaction interface. Minor cleavage sites of H2a are involved in binding with H3 in the nucleosome core. Two moderate cleavage sites of H2b and one

  18. Activation of H2O2-induced VSOR Cl- currents in HTC cells require phospholipase Cgamma1 phosphorylation and Ca2+ mobilisation

    DEFF Research Database (Denmark)

    Varela, Diego; Simon, Felipe; Olivero, Pablo

    2007-01-01

    Volume-sensitive outwardly rectifying (VSOR) Cl(-) channels participate in several physiological processes such as regulatory volume decrease, cell cycle regulation, proliferation and apoptosis. Recent evidence points to a significant role of hydrogen peroxide (H(2)O(2)) in VSOR Cl(-) channel...... activation. The aim of this study was to determine the signalling pathways responsible for H(2)O(2)-induced VSOR Cl(-) channel activation. In rat hepatoma (HTC) cells, H(2)O(2) elicited a transient increase in tyrosine phosphorylation of phospholipase Cgamma1 (PLCgamma1) that was blocked by PP2, a Src......-family protein kinases inhibitor. Also, H(2)O(2) triggered an increase in cytosolic [Ca(2+)] that paralleled the time course of PLCgamma1 phosphorylation. The H(2)O(2)-induced [Ca(2+)](i) rise was prevented by the generic phospholipase C (PLC) inhibitor U73122 and the inositol 1,4,5-trisphosphate-receptor (IP(3...

  19. H2A-DUBbing the mammalian epigenome: expanding frontiers for histone H2A deubiquitinating enzymes in cell biology and physiology.

    Science.gov (United States)

    Belle, Jad I; Nijnik, Anastasia

    2014-05-01

    Posttranslational modifications of histone H2A through the attachment of ubiquitin or poly-ubiquitin conjugates are common in mammalian genomes and play an important role in the regulation of chromatin structure, gene expression, and DNA repair. Histone H2A deubiquitinases (H2A-DUBs) are a group of structurally diverse enzymes that catalyze the removal ubiquitin from histone H2A. In this review we provide a concise summary of the mechanisms that mediate histone H2A ubiquitination in mammalian cells, and review our current knowledge of mammalian H2A-DUBs, their biochemical activities, and recent developments in our understanding of their functions in mammalian physiology. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Rb2SO4-CoSO4-H2O i Cs2SO4-CoSO4-H2O systems at 25 deg C

    International Nuclear Information System (INIS)

    Filippov, V.K.; Yakovleva, S.I.

    1979-01-01

    An isothermal method has been applied to examining the solubility in the M 2 SO 4 -CoSO 4 -H 2 O (M - Rb, Cs) systems at 25 deg C. The formation of solid compounds Rb 2 SO 4 xCoSO 4 x6H 2 O and Cs 2 SO 4 xCoSO 4 x6H 2 O had been established, which considerably differ in their solubility in water

  1. Localization and expression of histone H2A variants during mouse oogenesis and preimplantation embryo development.

    Science.gov (United States)

    Wu, B J; Dong, F L; Ma, X S; Wang, X G; Lin, F; Liu, H L

    2014-08-07

    Epigenetic modifications of the genome, such as histone H2A variants, ensure appropriate gene activation or silencing during oogenesis and preimplantation embryo development. We examined global localization and expression of the histone H2A variants, including H2A.Bbd, H2A.Z and H2A.X, during mouse oogenesis and preimplantation embryo development. Immunocytochemistry with specific antibodies against various histone H2A variants showed their localization and changes during oogenesis and preimplantation development. H2A.Bbd and H2A.Z were almost absent from nuclei of growing oocytes (except 5-day oocyte), whereas H2A.X was deposited in nuclei throughout oogenesis and in preimplantation embryos. In germinal vesicle (GV) oocyte chromatin, H2A.Bbd was detected as a weak signal, whereas no fluorescent signal was detected in GV breakdown (GVBD) or metaphase II (MII) oocytes; H2A.Z showed intense signals in chromatin of GV, GVBD and MII oocytes. H2A. Bbd showed very weak signals in both pronucleus and 2-cell embryo nuclei, but intense signals were detected in nuclei from 4-cell embryo to blastula. The H2A.Z signal was absent from pronucleus to morula chromatin, whereas a fluorescent signal was detected in blastula nuclei. Our results suggest that histone H2A variants are probably involved in reprogramming of genomes during oocyte meiosis or after fertilization.

  2. Open chain or chemically bonded structure of H2O4: The hydroperoxyl radical dimer

    International Nuclear Information System (INIS)

    Fitzgerald, G.; Lee, T.J.; Schaefer, H.F. III; Bartlett, R.J.

    1985-01-01

    The straight chain isomer H--O--O--O--O--H of H 2 O 4 is of considerable current interest in combustion and atmospheric chemistry. Ab initio quantum mechanical methods have been used to study the geometrical structure, energetics, and vibrational frequencies of this species. Double zeta (DZ) and double zeta plus polarization (DZ+P) basis sets have been used in this theoretical study, the latter designated O(9s5p1d/4s2p1d), H(4s1p/2s1p). These basis sets have been employed in conjunction with self--consistent field (SCF)= and configuration interaction (CI) methods, including variationally up to 470 935 configurations. For the straight chain isomer, stationary points of symmetry C/sub 2h/, C/sub i/, and C 1 have been identified, and correspond to Hessian indices 3,1, and 0, respectively. The equilibrium geometry, having no elements of symmetry at all, is relatively unique. The highest level of theory (unlinked cluster corrected DZ+P CI) predicts the straight chain structure of H 2 O 4 to lie slightly lower in total energy than the cyclic two-hydrogen bond isomer

  3. Calculation of inelastic helium atom scattering from H2/ NaCl(001)

    DEFF Research Database (Denmark)

    Bruch, L.W.; Hansen, Flemming Yssing; Traeger, F.

    2011-01-01

    The one-phonon inelastic low energy helium atom scattering theory is adapted to cases where the target monolayer is a p(1 × 1) commensurate square lattice. Experimental data for para-H2/NaCl(001) are re-analyzed and the relative intensities of energy loss peaks in the range 6 to 9 meV are determi......The one-phonon inelastic low energy helium atom scattering theory is adapted to cases where the target monolayer is a p(1 × 1) commensurate square lattice. Experimental data for para-H2/NaCl(001) are re-analyzed and the relative intensities of energy loss peaks in the range 6 to 9 me...... in the wave-packet-scattering calculation and a long series of Fourier amplitudes to represent the helium-target potential energy surface. A modified series is constructed in which a truncated Fourier expansion of the potential is constrained to give the exact value of the potential at some key points...... and which mimics the potential with fewer Fourier amplitudes. The shear horizontal phonon mode is again accessed by the helium scattering for small misalignment of the scattering plane relative to symmetry axes of the monolayer. For 1 misalignment, the calculated intensity of the longitudinal acoustic...

  4. A New Overpotential — Capacitance Mechanism for H2 Electrode

    Directory of Open Access Journals (Sweden)

    Glenn Wei

    2006-10-01

    Full Text Available The H2 electrode is commonly assumed to be a half-cell, 2 H+ 2e == H2, andexplained by the Nernst equation. We cannot assume that the H+ is easily reduced to H2 inan H2 saturated solution, and H2 becoming oxidized to H+ in a strongly acid solution againstthe equilibrium principle. How can the H2 gas is involved from a basic solution where thereis practically no H+ ions? Another equilibrium has been postulated, H2 (soln = 2H(adsorbed on metal = 2 H 2e. This paper reports the results of studying the H2 electrodeusing various techniques, such as adsorption, bubbling with H2, and N2, charging,discharging, and recharging, replacing the salt bridge with a conducting wire, etc. Aninteresting overpotential was observed that bubbling H2 into the solution caused a suddenchange of potential to more negative without changing the solution pH. The H2 may bereplaced by N2 to give a similar calibration curve without the overpotential. The resultscontradict the redox mechanism. When the Pt is separated by H2 coating, it cannot act as acatalyst in the solution. Our results seem to explain the H2 electrode mechanism as thecombination of its overpotential and capacitance potential. Bubbling of H2 or N2 onlyremoves interfering gases such as O2 and CO2. Since neither H2 nor N2 is involved in thepotential development, it is improper to call the H2 or N2 electrode. A term of pH / OH Ptelectrode, like the pH / OH glass electrode, is suggested.

  5. Conductivity And Thermal Stability of Solid Acid Composites CsH2PO4 /NaH2PO4/ SiO2

    International Nuclear Information System (INIS)

    Norsyahida Mohammad; Abu Bakar Mohamad; Abu Bakar Mohamad; Abdul Amir Hassan Kadhum

    2016-01-01

    Solid acid composites CsH 2 PO 4 / NaH 2 PO 4 / SiO 2 with different mole ratios of CsH 2 PO 4 and NaH 2 PO 4 to SiO 2 were synthesized and characterized. Preliminary infrared measurements of CsH 2 PO 4 and its composites indicated that hydrogen bonds breaking and formation were detected between 1710 to 2710 cm -1 , while the rotation of phosphate tetrahedral anions occurred between 900 and 1200 cm -1 . The superprotonic transition of CsH 2 PO 4 / NaH 2 PO 4 / SiO 2 composite was identified at superprotonic temperatures between 230 and 260 degree Celcius, under atmospheric pressure. This study reveals higher conductivity values for composites with higher CsH 2 PO 4 (CDP) content. Solid acid composite CDP 613 appeared as the composite with the highest conductivity that is 7.2x10 -3 S cm -1 at 230 degree Celcius. Thermal stability of the solid acid composites such as temperature of dehydration, melting and decomposition were investigated. The addition of NaH 2 PO 4 lowers the dehydration temperature of the solid acid composites. (author)

  6. Using H2O2 as oxidant in leaching of uranium ores. The new research on the reaction of H2O2 with Fe2+

    International Nuclear Information System (INIS)

    Gao Xizhen

    1997-05-01

    The new research on the reaction of H 2 O 2 with Fe 2+ has been studied. Through determining the electric potential, pH and O 2 release during the mutual titration between H 2 O 2 solution and FeSO 4 solution, deduced the chemical equations of H 2 O 2 (without free hydroxyl) oxidizing FeSO 4 and Fe 2 (SO 4 ) 3 oxidizing H 2 O 2 . The research results show that acid is a catalytic agent for decomposing H 2 O 2 to be O 2 and H 2 O besides iron ions. The maximum oxidizing potential is up to about 640 mV. While using H 2 O 2 as an oxidant in uranium heap leaching and in-situ leaching, controlling electric potential can be regarded as a method for adjusting the feeding speed of H 2 O 2 to keep the electric potential below 500 mV, thus the H 2 O 2 decomposition can be reduced. (13 refs., 3 tabs., 1 fig.)

  7. Nucleosome acidic patch promotes RNF168- and RING1B/BMI1-dependent H2AX and H2A ubiquitination and DNA damage signaling.

    Directory of Open Access Journals (Sweden)

    Justin W Leung

    2014-03-01

    Full Text Available Histone ubiquitinations are critical for the activation of the DNA damage response (DDR. In particular, RNF168 and RING1B/BMI1 function in the DDR by ubiquitinating H2A/H2AX on Lys-13/15 and Lys-118/119, respectively. However, it remains to be defined how the ubiquitin pathway engages chromatin to provide regulation of ubiquitin targeting of specific histone residues. Here we identify the nucleosome acid patch as a critical chromatin mediator of H2A/H2AX ubiquitination (ub. The acidic patch is required for RNF168- and RING1B/BMI1-dependent H2A/H2AXub in vivo. The acidic patch functions within the nucleosome as nucleosomes containing a mutated acidic patch exhibit defective H2A/H2AXub by RNF168 and RING1B/BMI1 in vitro. Furthermore, direct perturbation of the nucleosome acidic patch in vivo by the expression of an engineered acidic patch interacting viral peptide, LANA, results in defective H2AXub and RNF168-dependent DNA damage responses including 53BP1 and BRCA1 recruitment to DNA damage. The acidic patch therefore is a critical nucleosome feature that may serve as a scaffold to integrate multiple ubiquitin signals on chromatin to compose selective ubiquitinations on histones for DNA damage signaling.

  8. Polypeptide having or assisting in carbohydrate material degrading activity and uses thereof

    Science.gov (United States)

    Schooneveld-Bergmans, Margot Elisabeth Francoise; Heijne, Wilbert Herman Marie; Los, Alrik Pieter

    2016-02-16

    The invention relates to a polypeptide which comprises the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 76% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 76% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional polypeptide and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  9. Basal serum pancreatic polypeptide is dependent on age and gender in an adult population

    DEFF Research Database (Denmark)

    Brimnes Damholt, M; Rasmussen, B K; Hilsted, L

    1997-01-01

    This study is the first epidemiologically based study of basal levels of serum pancreatic polypeptide (s-PP). The basal level of serum PP has become a field of interest mainly due to the role of PP as an endocrine tumour marker, and as a marker of pancreatic neuroendocrine function after pancreas...... a monospecific radioimmunoassay. Fasting serum pancreatic polypeptide depended on age and gender. The results demonstrated that fasting pancreatic polypeptide levels increase exponentially with age. Fitted separately for each sex, basal serum pancreatic polypeptide was found to increase by approximately 3% per...... reports on the fasting levels of serum pancreatic polypeptide are most likely due to lack of adjustment for age and gender. Thus, variation due to age and gender should be considered in evaluating fasting levels of serum pancreatic polypeptide. Whether similar considerations are important when evaluating...

  10. Chemical reaction surface vibrational frequencies evaluated in curvilinear internal coordinates: Application to H + CH(4) H(2) + CH(3).

    Science.gov (United States)

    Banks, Simon T; Clary, David C

    2009-01-14

    We consider the general problem of vibrational analysis at nonglobally optimized points on a reduced dimensional reaction surface. We discuss the importance of the use of curvilinear internal coordinates to describe molecular motion and derive a curvilinear projection operator to remove the contribution of nonzero gradients from the Hessian matrix. Our projection scheme is tested in the context of a two-dimensional quantum scattering calculation for the reaction H + CH(4) --> H(2) + CH(3) and its reverse H(2) + CH(3) --> H + CH(4). Using zero-point energies calculated via rectilinear and curvilinear projections we construct two two-dimensional, adiabatically corrected, ab initio reaction surfaces for this system. It is shown that the use of curvilinear coordinates removes unphysical imaginary frequencies observed with rectilinear projection and leads to significantly improved thermal rate constants for both the forward and reverse reactions.

  11. Vibrationally inelastic integral cross sections for the scattering of He from H2

    International Nuclear Information System (INIS)

    Lin, C.S.; Secrest, D.

    1979-01-01

    Integral cross sections are presented for the scattering of He from H 2 on the Gordon--Secrest potential. Results are reported at four energies, two above the first excited vibrational state and two above the second excited vibrational state. The energies are high enough that the vibrational transition from the ground to the first vibrational state is significant. Enough channels were included in the calculation to ensure that the integral cross sections are correct to two or three figures for the model potential used. A discussion of convergence is included. These accurate cross sections serve as test points for approximate calculations of vibrational energy transfer. The results are compared with the coupled states approximation, effective potential calculations, the semiclassical strong-coupling correspondence principle, and classical trajectory calculations which had been reported earlier for this potential model by other workers. Results of the comparisons are discussed

  12. Nuclear quadrupole resonance in CuCl2.2H2O

    International Nuclear Information System (INIS)

    Liu, Y.S.; Peixoto, L.T.

    1975-01-01

    The electric field gradient (EFG) at the Cl - site of CuCl 2 .2H 2 O has been calculated on the basis of a point charge model plus the contribution of the covalent bond between nearest copper and chlorine ions. In the calculations of the EFG at Cu ++ site, it has been included the contribution of the 3d 9 electrons in the valence shell of copper and neglected the effect of chemical bonding. After comparison with experimental NQR results, it has been discussed the shielding effect of the core electrons of both ions and established values for the so called Sternheimer factors. It has been presented a value for the ionicity of chlorine in the crystal and calculated the temperature dependence of the quadrupole splitting of the copper nucleus [pt

  13. A role for interleukin-33 in T(H)2-polarized intestinal inflammation?

    DEFF Research Database (Denmark)

    Seidelin, J B; Rogler, G; Nielsen, O H

    2011-01-01

    Interleukin 33 (IL-33) is a recently discovered cytokine member of the IL-1 superfamily that is widely expressed in fixed tissue cells, including endothelial and epithelial cells. IL-33 induces helper T cells, mast cells, eosinophils, and basophils to produce type-2 cytokines through binding...... to the ST2/IL-1 receptor accessory protein complex. Recent studies have shown IL-33 to be upregulated in intestinal parasite infection and in epithelial cells and myofibroblasts in ulcerative colitis (UC). The findings point to a role for IL-33 in directing the T(H)2-type immune responses in these types...... of mucosal inflammation. As the IL-33/ST2 receptor axis can be manipulated by various blocking antibodies, this could be a potential therapeutic target in the future treatment of UC....

  14. VLA observations of the 6-cm H2CO absorption towards Sgr A West

    International Nuclear Information System (INIS)

    Whiteoak, J.B.; Gardner, F.F.

    1983-01-01

    The distribution of the 6-cm H 2 CO absorption across Sgr A has been measured with a beam of 3.6 x 3.5 arcsec 2 . Velocities in the range - 9 to + 88 km s - 1 were covered with a resolution of 3.1 km s - 1 and absorption was detected only near +40 and O km s - 1 . The former occurred against the extended continuum emission of Sgr A West with an optical depth of approximately 0.1, but not against the intense unresolved source thought to be associated with the nucleus of our Galaxy. There are difficulties with the simplest interpretation, in which the molecular cloud is behind the point source. All of the zero-velocity absorption takes place well in front of Sgr A, except at +3 km s - 1 where some of the absorption may occur near the Galactic Centre. (author)

  15. The competition between H2O and CO2 adhesion at reservoir conditions

    DEFF Research Database (Denmark)

    Sølling, Theis Ivan; Budi, Akin; Mogensen, K.

    2015-01-01

    Density functional theory was applied (B3LYP) to answer whether conditions exist where CO2 adhesion to three different lithologies becomes stronger than H2O adhesion. The answer is that it does not seem to be the case. This is taken to indicate that the reservoirs that we have represented by simple...... models are prone to CO2 storage. Moreover, we have obtained an overview of the effect of including entropy contributions and zero point vibrational energies in the calculation of the adhesion energies. The consequence of applying simple dispersion and solvent models are also addressed. The study is based...... around very simplified model systems of calcite, quartz and clays in order address the basic effects. Rather than attempting to obtain quantitative agreement we are observing the qualitative trends. When entropy, ZPE and a continuum model is included the result is smaller binding energies. However...

  16. Teledyne H1RG, H2RG, and H4RG Noise Generator

    Science.gov (United States)

    Rauscher, Bernard J.

    2015-01-01

    This paper describes the near-infrared detector system noise generator (NG) that we wrote for the James Webb Space Telescope (JWST) Near Infrared Spectrograph (NIRSpec). NG simulates many important noise components including; (1) white "read noise", (2) residual bias drifts, (3) pink 1/f noise, (4) alternating column noise, and (5) picture frame noise. By adjusting the input parameters, NG can simulate noise for Teledyne's H1RG, H2RG, and H4RG detectors with and without Teledyne's SIDECAR ASIC IR array controller. NG can be used as a starting point for simulating astronomical scenes by adding dark current, scattered light, and astronomical sources into the results from NG. NG is written in Python-3.4.

  17. Solvent-free liquid crystals and liquids based on genetically engineered supercharged polypeptides with high elasticity.

    Science.gov (United States)

    Liu, Kai; Pesce, Diego; Ma, Chao; Tuchband, Michael; Shuai, Min; Chen, Dong; Su, Juanjuan; Liu, Qing; Gerasimov, Jennifer Y; Kolbe, Anke; Zajaczkowski, Wojciech; Pisula, Wojciech; Müllen, Klaus; Clark, Noel A; Herrmann, Andreas

    2015-04-17

    A series of solvent-free elastin-like polypeptide liquid crystals and liquids are developed by electrostatic complexation of supercharged elastin-like polypeptides with surfactants. The smectic mesophases exhibit a high elasticity and the values can be easily tuned by varying the alkyl chain lengths of the surfactants or the lengths of the elastin-like polypeptides. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. H + H2 on LEPS and Porter-Karplus surfaces;Quasiclassical differential cross sections for reactive scattering

    International Nuclear Information System (INIS)

    Jorgensen, A.D.; Gislason, E.A.; Hillenbrand, E.A.

    1981-01-01

    The reactive differential cross section is determined by the use of a fourier sine series for the H + H 2 reaction on the Porter Karplus and LEPS surfaces. The A + BC program was used to run quasiclassical trajectories. Saddle-point properties are compared, including those for SLTH surfaces. The use of the Fourier sine series enables one to obtain very accurate differential cross sections, allowing precise comparison of the reaction dynamics on different potential energy surfaces and at different energies

  19. Decapado del acero inoxidable AISI 316L utilizando una mezcla ecológica de H2O2-H2SO4-HF

    Directory of Open Access Journals (Sweden)

    Gómez, P. P.

    2005-12-01

    Full Text Available This study reports the pickling of austenitic AISI 316L stainless steel (SS using a mixture of hydrogen peroxide (H2O2, sulphuric acid (H2SO4 and hydrofluoric acid (HF at pH 2.0. The stability of H2O2 was also studied using different concentrations of ferric ion from 0 to 40 g/l and temperature from 25 to 60 °C. The pickling rate at 50 °C in the presence and absence of 40 g/l ferric ion was 2.6 and 0.2 mg/dm2 day (mdd, respectively. p-Toluene sulphonic acid was used as stabilizer of H2O2.En la presente investigación se estudia el decapado del acero inoxidable AISI 316L utilizando una mezcla de agua oxigenada (H2O2 y los ácidos sulfúrico (H2SO4 y fluorhídrico (HF a pH 2,0. La estabilidad de la mezcla H2O2-H2SO4-HF se ha ensayado variando el contenido de iones férrico de O a 40 g/l y la temperatura de 25 a 60 °C. La velocidad de decapado a 50 °C ha sido de 2,6 y 0,2 mg/dm2 día (mdd, en ausencia y presencia de 40 g/l de iones férrico, respectivamente. Se ha utilizado el ácido p-toluen sulfónico como estabilizante del H2O2.

  20. Formation of H2O+ and H3O+ Cations in Reactions of OH+ and H2O+ with H2: Experimental Studies of the Reaction Rate Coefficients from T = 15 to 300 K

    Science.gov (United States)

    Dung Tran, Thuy; Rednyk, Serhiy; Kovalenko, Artem; Roučka, Štěpán; Dohnal, Petr; Plašil, Radek; Gerlich, Dieter; Glosík, Juraj

    2018-02-01

    {{OH}}+ and {{{H}}}2{{{O}}}+ cations play a significant role in the chemistry of the cold interstellar medium and hence their hydrogen abstraction reactions with {{{H}}}2 have to be included in ion chemical models. The reactions lead directly or indirectly to {{{H}}}3{{{O}}}+ ions that subsequently recombine with electrons and dissociate into H atoms and {{{H}}}2{{O}}. The experiments described in this paper provide rate coefficients ({k}{{OH}+} and {k}{{{H}}2{{{O}}}+}) for the reactions of {{OH}}+ and {{{H}}}2{{{O}}}+ with {{{H}}}2 over a wide temperature range (from 15 to 300 K). A cryogenic 22-pole RF ion trap instrument was employed for this purpose. It was found that {k}{{OH}+} increases from (0.76+/- 0.30)× {10}-9 {{cm}}3 {{{s}}}-1 at 17 K to (1.24+/- 0.25)× {10}-9 {{cm}}3 {{{s}}}-1 at 263 K while {k}{{{H}}2{{{O}}}+} is nearly constant, varying from (0.93+/- 0.35) × {10}-9 {{cm}}3 {{{s}}}-1 at 17 K to (1.00+/- 0.25)× {10}-9 {{cm}}3 {{{s}}}-1 at 218 K.

  1. Inhibition of Mitochondrial Bioenergetics by Esterase-Triggered COS/H2S Donors.

    Science.gov (United States)

    Steiger, Andrea K; Marcatti, Michela; Szabo, Csaba; Szczesny, Bartosz; Pluth, Michael D

    2017-08-18

    Hydrogen sulfide (H 2 S) is an important biological mediator, and synthetic H 2 S donating molecules provide an important class of investigative tools for H 2 S research. Here, we report esterase-activated H 2 S donors that function by first releasing carbonyl sulfide (COS), which is rapidly converted to H 2 S by the ubiquitous enzyme carbonic anhydrase (CA). We report the synthesis, self-immolative decomposition, and H 2 S release profiles of the developed scaffolds. In addition, the developed esterase-triggered COS/H 2 S donors exhibit higher levels of cytotoxicity than equivalent levels of Na 2 S or the common H 2 S donors GYY4137 and AP39. Using cellular bioenergetics measurements, we establish that the developed donors reduce cellular respiration and ATP synthesis in BEAS 2B human lung epithelial cells, which is consistent with COS/H 2 S inhibition of cytochrome c oxidase in the mitochondrial respiratory chain although not observed with common H 2 S donors at the same concentrations. Taken together, these results may suggest that COS functions differently than H 2 S in certain biological contexts or that the developed donors are more efficient at delivering H 2 S than other common H 2 S-releasing motifs.

  2. The responses of the four main substitution mechanisms of H in olivine to H2O activity at 1050 °C and 3 GPa

    Science.gov (United States)

    Tollan, Peter M. E.; Smith, Rachel; O'Neill, Hugh St. C.; Hermann, Jörg

    2017-12-01

    The water solubility in olivine ({C}_{{H}_2O}) has been investigated at 1050 °C and 3 GPa as a function of water activity ({a}_{{H}_2O}) at subsolidus conditions in the piston-cylinder apparatus, with {a}_{{H}_2O} varied using H2O-NaCl fluids. Four sets of experiments were conducted to constrain the effect of {a}_{{H}_2O} on the four main substitution mechanisms. The experiments were designed to grow olivine in situ and thus achieve global equilibrium (G-type), as opposed to hydroxylating olivine with a pre-existing point-defect structure and impurity content (M-type). Olivine grains from the experiments were analysed with polarised and unpolarised FTIR spectroscopy, and where necessary, the spectra have been deconvoluted to quantify the contribution of each substitution mechanism. Olivine buffered with magnesiowüstite produced absorbance bands at high wavenumbers ranging from 3566 to 3612 cm-1. About 50% of the total absorbance was found parallel to the a-axis, 30% parallel to the b-axis and 20% parallel to the c-axis. The total absorbance and hence water concentration in olivine follows the relationship of {C}_{{H}_2O}∝ {a_{{H}_2O}}^2 , indicating that the investigated defect must involve four H atoms substituting for one Si atom (labelled as [Si]). Forsterite buffered with enstatite produced an absorbance band exclusively aligned parallel the c-axis at 3160 cm-1. The band position, polarisation and observed {C}_{{H}_2O}∝ {a}_{{H}_2O} are consistent with two H substituting for one Mg (labelled as [Mg]). Ti-doped, enstatite-buffered olivine displays absorption bands, and polarisation typical of Ti-clinohumite point defects where two H on the Si-site are charge-balanced by one Ti on a Mg-site (labelled as [Ti]). This is further supported by {C}_{{H}_2O}∝ {a}_{{H}_2O} and a 1:1 relationship of molar H2O and TiO2 in these experiments. Sc-doped, enstatite-buffered experiments display a main absorption band at 3355 cm-1 with {C}_{{H}_2O}∝ {a_{{H}_2O}}^{0

  3. Effect of H2 addition on combustion characteristics of dimethyl ether jet diffusion flame

    International Nuclear Information System (INIS)

    Kang, Yinhu; Lu, Xiaofeng; Wang, Quanhai; Gan, Lu; Ji, Xuanyu; Wang, Hu; Guo, Qiang; Song, Decai; Ji, Pengyu

    2015-01-01

    Highlights: • DME- and H 2 -dominated combustion regimes were quantitatively characterized. • The flame structure changed significantly when H 2 addition was above 60 vol.%. • An empirical correlation for normalized flame entrainment rate was developed. • The optimal H 2 addition to DME was 60 vol.% in the practical engineering. - Abstract: In this paper, experiments and numerical calculations were conducted to investigate the effect of H 2 addition on dimethyl ether (DME) jet diffusion flame behaviors, in terms of thermal and chemical structures, reaction zone size, flame entrainment, and NOx and CO emission indices. A wide range of H 2 additions from pure DME to pure H 2 were involved herein, while maintaining the volumetric flow rate of fuel mixture constant. The results indicate that when H 2 mole fraction in the fuel mixture exceeded 60%, the blended fuel was converted to H 2 -dominated. Besides, the flames behaved rather distinctly at the DME- and H 2 -dominated regimes. With the increment in H 2 addition, flame temperature, H 2 , H, O, and OH concentrations increased gradually, but concentrations of the intermediate hydrocarbons (such as CO, CH 2 O, CH 2 , and CH 3 ) decreased on the contrary. Additionally, after the flame became H 2 -dominated, the species concentrations varied increasingly quickly with H 2 addition. The reaction zone length and width decreased nearly linearly with H 2 addition at the DME- and H 2 -dominated regimes. But the decreasing speed of reaction zone length became faster after the flame was converted to H 2 -dominated. At the DME-dominated regime, the dependence of flame entrainment coefficient (C e ) on H 2 addition was rather small. While at the H 2 -dominated regime, C e increased increasingly quickly with H 2 addition. Moreover, with the increment in H 2 addition, NOx emission index increased and CO emission index decreased gradually. In addition, at the DME-dominated regime, NOx emission index increased fairly slowly

  4. Well-defined (co)polypeptides bearing pendant alkyne groups

    KAUST Repository

    Zhao, Wei

    2016-03-18

    A novel metal-free strategy, using hydrogen-bonding catalytic ring opening polymerization of acetylene-functionalized N-carboxy anhydrites of α-amino acids, was developed for the synthesis of well-defined polypeptides bearing pendant alkyne groups. This method provides an efficient way to synthesize novel alkyne-functionalized homopolypeptides (A) and copolypeptides, such as AB diblock (B: non-functionalized), ABA triblock and star-AB diblock, as well as linear and star random copolypeptides, precursors of a plethora complex macromolecular architectures by click chemistry.

  5. Ab initio study of alanine polypeptide chain twisting

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Yakubovich, Alexander V.; Solov'yov, Andrey V.

    2006-01-01

    We have investigated the potential energy surfaces for alanine chains consisting of three and six amino acids. For these molecules we have calculated potential energy surfaces as a function of the Ramachandran angles ph$ and psi, which are widely used for the characterization of the polypeptide...... and with the available experimental data extracted from the Protein Data Base. This comparison demonstrates a reasonable correspondence of the most prominent minima on the calculated potential energy surfaces to the experimentally measured angles phi and psi for alanine chains appearing in native proteins. We have also...

  6. Functional Modification of Thioether Groups in Peptides, Polypeptides, and Proteins.

    Science.gov (United States)

    Deming, Timothy J

    2017-03-15

    Recent developments in the modification of methionine and other thioether-containing residues in peptides, polypeptides, and proteins are reviewed. Properties and potential applications of the resulting functionalized products are also discussed. While much of this work is focused on natural Met residues, modifications at other side-chain residues have also emerged as new thioether-containing amino acids have been incorporated into peptidic materials. Functional modification of thioether-containing amino acids has many advantages and is a complementary methodology to the widely utilized methods for modification at cysteine residues.

  7. Reaction mechanisms in the radiolysis of peptides, polypeptides and proteins

    International Nuclear Information System (INIS)

    Garrison, W.M.

    1985-01-01

    The purpose of this review is to bring together and to correlate the wide variety of experimental studies that provide information on the reaction products and reaction mechanisms involved in the radiolysis of peptides, polypeptides and proteins (including chromosomal proteins) in both aqueous and solid-state systems. The comparative radiation chemistry of these systems is developed in terms of specific reactions of the peptide main-chain and the aliphatic, aromatic-unsaturated and sulfur-containing side-chains. Information obtained with the various experimental techniques of product analysis, competition kinetics, spin-trapping, pulse radiolysis and ESR spectroscopy is included. 147 refs

  8. Reaction mechanisms in the radiolysis of peptides, polypeptides and proteins

    Energy Technology Data Exchange (ETDEWEB)

    Garrison, W.M.

    1985-01-01

    The purpose of this review is to bring together and to correlate the wide variety of experimental studies that provide information on the reaction products and reaction mechanisms involved in the radiolysis of peptides, polypeptides and proteins (including chromosomal proteins) in both aqueous and solid-state systems. The comparative radiation chemistry of these systems is developed in terms of specific reactions of the peptide main-chain and the aliphatic, aromatic-unsaturated and sulfur-containing side-chains. Information obtained with the various experimental techniques of product analysis, competition kinetics, spin-trapping, pulse radiolysis and ESR spectroscopy is included. 147 refs.

  9. Compositions comprising a polypeptide having cellulolytic enhancing activity and a bicycle compound and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Feng; Sweeney, Matthew; Quinlan, Jason

    2015-06-16

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a bicyclic compound. The present invention also relates to methods of using the compositions.

  10. Compositions comprising a polypeptide having cellulolytic enhancing activity and a quinone compound and uses thereof

    Science.gov (United States)

    Quinlan, Jason; Xu, Feng; Sweeney, Matthew

    2016-03-01

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a quinone compound. The present invention also relates to methods of using the compositions.

  11. Thermal aggregation behaviour of soy protein: characteristics of different polypeptides and sub-units.

    Science.gov (United States)

    He, Xiu-Ting; Yuan, De-Bao; Wang, Jin-Mei; Yang, Xiao-Quan

    2016-03-15

    Due to the differences in structure and composition of glycinin and β-conglycinin, they exhibit different characteristics during heat treatment. In present study, the thermal aggregation behaviour of glycinin, β-conglycinin and their isolated sub-units was investigated at pH 7.0. Acidic polypeptides, basic polypeptides, αα' and β sub-units of soy protein were denatured during the isolation process. The degree of aggregation of protein fractions after heat treatment was in the order: denatured basic polypeptides > native glycinin > denatured β sub-unit > native β-conglycinin > denatured acidic polypeptides > denatured αα' sub-units. Glycinin, β-conglycinin, acidic polypeptides and αα'/β sub-units exhibited different changing trends of surface hydrophobicity with increasing temperature. The αα' sub-units showed higher ability to suppress thermal aggregation of basic polypeptides than β sub-units during heat treatment. The β sub-units were shown to form soluble aggregates with glycinin after heating. The interaction mechanism of αα' and β sub-units heated with basic polypeptides was proposed. For the β sub-units-basic polypeptides mixed system, more hydrophobic chains were binding together and buried inside during heat treatment, which resulted in lower surface hydrophobicity. The αα' sub-units-basic polypeptides mixed system was considered to be a stable system with higher surface hydrophobicity after being heated. © 2015 Society of Chemical Industry.

  12. Decolorization and Mineralization of Reactive Dyes, by the H2O2/UV Process With Electrochemically Produced H2O2

    NARCIS (Netherlands)

    Jeric, T.; Bisselink, R.J.M.; Tongeren, W. van; Marechal. A.M. Le

    2013-01-01

    Decolorization of Reactive Red 238, Reactive Orange 16, Reactive Black 5 and Reactive Blue 4 was studied in the UV/H2O2 process with H2O2 being produced electrochemically. The experimental results show that decolorization increased considerably when switching on the electrochemical production of

  13. Structural Insights into the Association of Hif1 with Histones H2A-H2B Dimer and H3-H4 Tetramer.

    Science.gov (United States)

    Zhang, Mengying; Liu, Hejun; Gao, Yongxiang; Zhu, Zhongliang; Chen, Zijun; Zheng, Peiyi; Xue, Lu; Li, Jixi; Teng, Maikun; Niu, Liwen

    2016-10-04

    Histone chaperones are critical for guiding specific post-transcriptional modifications of histones, safeguarding the histone deposition (or disassociation) of nucleosome (dis)assembly, and regulating chromatin structures to change gene activities. HAT1-interacting factor 1 (Hif1) has been reported to be an H3-H4 chaperone and to be involved in telomeric silencing and nucleosome (dis)assembly. However, the structural basis for the interaction of Hif1 with histones remains unknown. Here, we report the complex structure of Hif1 binding to H2A-H2B for uncovering the chaperone specificities of Hif1 on binding to both the H2A-H2B dimer and the H3-H4 tetramer. Our findings reveal that Hif1 interacts with the H2A-H2B dimer and the H3-H4 tetramer via distinct mechanisms, suggesting that Hif1 is a pivotal scaffold on alternate binding of H2A-H2B and H3-H4. These specificities are conserved features of the Sim3-Hif1-NASP interrupted tetratricopeptide repeat proteins, which provide clues for investigating their potential roles in nucleosome (dis)assembly. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Ultra Low Air and H2 Permeability Cryogenic Bladder Materials for Inflatable Habitats, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NanoSonic has recently developed a hydrogen (H2) dispenser hose to realize H2 as a safe, reliable, and cost competitive replacement for gasoline. NanoSonic's...

  15. Nonadiabatic quantum wave packet dynamics of the H + H2 reaction ...

    Indian Academy of Sciences (India)

    Administrator

    ; nonadiabatic reaction dyanamics; coriolis coupling. 1. Introduction. The H + H2H2 + H exchange reaction has been and still is the cornerstone in the experimental and theo- retical research in the gas phase chemical reaction dynamics. 1.

  16. Vasoactive intestinal polypeptide and other preprovasoactive intestinal polypeptide-derived peptides in the female and male genital tract: localization, biosynthesis, and functional and clinical significance

    DEFF Research Database (Denmark)

    Ottesen, B; Fahrenkrug, J

    1995-01-01

    in the control of erection. Vasoactive intestinal polypeptide has been suggested as a causative factor in some diseases of the genital organs (e.g., it may play a pathophysiologic role in male impotence and the peptide is currently used in the treatment of this condition). Vasoactive intestinal polypeptide may...... be important for control of the low resistance in the fetomaternal vascular bed and is therefore a putative factor involved in the development of preeclampsia. The therapeutic potential of vasoactive intestinal polypeptide and future agonists and antagonists will be revealed by ongoing and forthcoming studies....

  17. Investigation into complexing in ZrO2-H2SO4-Rb2SO4(RbCl)-H2O system

    Energy Technology Data Exchange (ETDEWEB)

    Sozinova, Yu.P.; Motov, D.L.; Rys' kina, M.P.

    1986-12-01

    Solubility method is used to study zirconium and rubidium sulfate complexing: Rb4Zr4O(OH)4(SO4)7x5H2O, RbZrOH(SO4)2x1.5H2O, Rb2Zr(SO4)3x2H2O and Rb4Zr(SO4)4 in ZrO2-H2SO4-Rb2SO4(RbCl)-H2O system at 75 deg C. Introduction of RbCl instead of Rb2SO4 in the system is shown to result in change of concentration boundaries of phase existence, in a less degree - their solubility, as well as in increase of crystal size.

  18. Ce2(SO4)3-H2SO4-(NH4)2SO4-H2O system at 70 deg C

    International Nuclear Information System (INIS)

    Belokoskov, V.I.; Skovorodskaya, V.P.; Trofimov, G.V.

    1978-01-01

    The method of isothermal solubility was used to study the Ce 2 (SO 4 ) 3 -H 2 SO 4 -(NH 4 ) 2 SO 4 -H 2 O system at 70 deg C. It has been established that two solid phases: Ce 2 (SO 4 ) 3 x(NH 4 ) 2 SO 4 and Ce 2 (SO 4 ) 3 x(NH 4 ) 2 SO 4 x2H 2 O, crystallize in the system at 70 deg C. The dihydrate crystallizes in a system comprising solutions which contain up to 40% H 2 SO 4 . The anhydrous cerium sulfate starts crystallizing at higher H 2 SO 4 concentrations. As the sulfuric acide concentration in the solution increases, with the ammonium sulfate content remaining constant, the solubility of the dihydrate slowly decreases. Addition of ammonium sulfate causes a sharper decrease in the solubility

  19. Involvement of endogenous antioxidant systems in the protective activity of pituitary adenylate cyclase-activating polypeptide against hydrogen peroxide-induced oxidative damages in cultured rat astrocytes.

    Science.gov (United States)

    Douiri, Salma; Bahdoudi, Seyma; Hamdi, Yosra; Cubì, Roger; Basille, Magali; Fournier, Alain; Vaudry, Hubert; Tonon, Marie-Christine; Amri, Mohamed; Vaudry, David; Masmoudi-Kouki, Olfa

    2016-06-01

    Astroglial cells possess an array of cellular defense mechanisms, including superoxide dismutase (SOD) and catalase antioxidant enzymes, to prevent damages caused by oxidative stress. Nevertheless, astroglial cell viability and functionality can be affected by significant oxidative stress. We have previously shown that pituitary adenylate cyclase-activating polypeptide (PACAP) is a potent glioprotective agent that prevents hydrogen peroxide (H2 O2 )-induced apoptosis in cultured astrocytes. The purpose of this study was to investigate the potential protective effect of PACAP against oxidative-generated alteration of astrocytic antioxidant systems. Incubation of cells with subnanomolar concentrations of PACAP inhibited H2 O2 -evoked reactive oxygen species accumulation, mitochondrial respiratory burst, and caspase-3 mRNA level increase. PACAP also stimulated SOD and catalase activities in a concentration-dependent manner, and counteracted the inhibitory effect of H2 O2 on the activity of these two antioxidant enzymes. The protective action of PACAP against H2 O2 -evoked inhibition of antioxidant systems in astrocytes was protein kinase A, PKC, and MAP-kinase dependent. In the presence of H2 O2 , the SOD blocker NaCN and the catalase inhibitor 3-aminotriazole, both suppressed the protective effects of PACAP on SOD and catalase activities, mitochondrial function, and cell survival. Taken together, these results indicate that the anti-apoptotic effect of PACAP on astroglial cells can account for the activation of endogenous antioxidant enzymes and reduction in respiration rate, thus preserving mitochondrial integrity and preventing caspase-3 expression provoked by oxidative stress. Considering its powerful anti-apoptotic and anti-oxidative properties, the PACAPergic signaling system should thus be considered for the development of new therapeutical approaches to cure various pathologies involving oxidative neurodegeneration. We propose the following cascade for the

  20. Anomalous absorption in H2CN and CH2CN molecules

    Indian Academy of Sciences (India)

    Abstract. Structures of H2CN and CH2CN molecules are similar to that of H2CO mole- cule. The H2CO has shown anomalous absorption for its transition 111 − 110 at 4.8 GHz in a number of cool molecular clouds. Though the molecules H2CN and CH2CN have been identified in TMC-1 and Sgr B2 through some ...

  1. Water Radiolysis: Influence of Oxide Surfaces on H2 Production under Ionizing Radiation

    Directory of Open Access Journals (Sweden)

    Sophie Le Caër

    2011-02-01

    Full Text Available The radiolysis of water due to ionizing radiation results in the production of electrons, H· atoms, ·OH radicals, H3O+ ions and molecules (dihydrogen H2 and hydrogen peroxide H2O2. A brief history of the development of the understanding of water radiolysis is presented, with a focus on the H2 production. This H2 production is strongly modified at oxide surfaces. Different parameters accounting for this behavior are presented.

  2. Anomalous absorption in H2CN and CH2CN molecules

    Indian Academy of Sciences (India)

    http://www.ias.ac.in/article/fulltext/pram/071/01/0023-0032. Keywords. Interstellar molecules; H2CN; CH2CN. Abstract. Structures of H2CN and CH2CN molecules are similar to that of H2CO molecule. The H2CO has shown anomalous absorption for its transition 111 - 110 at 4.8 GHz in a number of cool molecular clouds.

  3. On the role of the termolecular reactions 2O2+ H2→ 2HO2and 2O2+ H2→ H + HO2+ O2in formation of the first radicals in hydrogen combustion: ab initio predictions of energy barriers.

    Science.gov (United States)

    Monge-Palacios, M; Rafatijo, Homayoon

    2017-01-18

    We have investigated the role of termolecular reactions in the early chemistry of hydrogen combustion. We performed molecular chemical dynamics simulations using ReaxFF in LAMMPS to identify potential initial reactions for a 1 : 4 mixture of H 2  : O 2 in the NVT ensemble at density 276.3 kg m -3 and ∼3000 K (∼4000 atm) and ∼4000 K (∼5000 atm), and then characterized the saddle points for those reactions using ab initio methods: CCSD(T) = FC/cc-pVTZ//MP2/6-31G, CCSD(T) = FULL/aug-cc-pVTZ//CCSD = FC/cc-pVTZ and CASSCF MP2/6-31G//MP2/6-31G. The main initial reaction is H 2 + O 2 → H + HO 2 , frequently occurring in the presence of a second O 2 as a third body; that is, 2O 2 + H 2 → H + HO 2 + O 2 . The second most frequent reaction is 2O 2 + H 2 → 2HO 2 . We found three saddle points on the triplet PES of these termolecular reactions: one for 2O 2 + H 2 → H + HO 2 + O 2 and two for 2O 2 + H 2 → 2HO 2 . In the latter case, one has a symmetric structure consistent with simultaneous formation of two HO 2 and the other corresponds to a bimolecular reaction between O 2 and H 2 that is "interrupted" by a second O 2 before going to completion. The classical barrier height of the symmetric saddle point for 2O 2 + H 2 → 2HO 2 is 49.8 kcal mol -1 . The barrier to H 2 + O 2 → H + HO 2 is 58.9 kcal mol -1 . The termolecular reaction will be competitive with H 2 + O 2 → H + HO 2 only at sufficiently high pressures.

  4. The system Ba(H2PO4)2-Sr(H2PO4)2-H3PO4(30%)-H2O at 25, 40 and 60 deg C

    International Nuclear Information System (INIS)

    Taranenko, N.P.; Serebrennikova, G.M.; Stepin, B.D.; Oboznenko, Yu.V.

    1982-01-01

    The system Ba(H 2 PO 4 ) 2 -Sr(H 2 PO 4 ) 2 -H 3 PO 4 (30%)-H 2 O (25 deg C) belongs to eutonic type systems. Solubility isotherms of salt components at 40 and 60 deg C are calculated. Polytherms (25-60 deg C) of solubility of monosubstituted barium and strontium phosphates in 30-60% H 3 PO 4 are obtained. The value of cocrystallization coefficient of Sr 2 + and Ba(H 2 PO 4 ) 2 Dsub(Sr)=0.042+-0.005 remains stable in the temperature range of 25-60 deg C and concentrations 30-60% phosphoric acid at initial content [Sr 2 + ]=1x10 - 2 mass%

  5. Rapid desensitization of the histamine H2 receptor on the human monocytic cell line U937

    NARCIS (Netherlands)

    Smit, M J; Leurs, R; Shukrula, S R; Bast, A; Timmerman, H

    1994-01-01

    In the present study we have subjected the histamine H2 receptor on the monocytic cell line U937 to a thorough pharmacological characterization using a series of selective histamine H1, H2 and H3 receptor agonists and antagonists. Recent reports have demonstrated the existence of a histamine H2

  6. Reassessing the variability in atmospheric H2 using the two-way nested TM5 model

    Energy Technology Data Exchange (ETDEWEB)

    Pieterse, G.; Batenburg, A.M; Roeckmann, T. [Institute for Marine and Atmospheric Research Utrecht (IMAU), Utrecht (Netherlands); Krol, M.C. [Department of Meteorology and Air Quality at Wageningen University, Wageningen (Netherlands); Brenninkmeijer, C.A.M. [Max-Planck-Institut fuer Chemie, Air Chemistry Division, Mainz (Germany); Popa, M.E.; Vermeulen, A.T. [Department of Air Quality and Climate Research at the Energy Research Centre of the Netherlands ECN, Petten (Netherlands); O' Doherty, S.; Grant, A. [School of Chemistry, University of Bristol, Bristol (United Kingdom); Steele, L.P.; Krummel, P.B.; Langenfelds, R.L. [Centre for Australian Weather and Climate Research, CSIRO Marine and Atmospheric Research, Aspendale, Victoria (Austria); Wang, H.J. [School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA (United States); Schmidt, M.; Yver, C. [Laboratoire des Sciences du Climat et de l' Environnement (LSCE), Gif-sur-Yvette (France); Jordan, A. [Max-Planck Institut fuer Biogeochemie, Jena (Germany); Engel, A. [Institut fuer Meteorologie und Geophysik, Goethe-Universitaet Frankfurt, Frankfurt (Germany); Fisher, R.E.; Lowry, D.; Nisbet, E.G. [Department of Earth Sciences, Royal Holloway, University of London, Egham (United Kingdom); Reimann, S.; Vollmer, M.K.; Steinbacher, M. [Empa, Swiss Federal Institute for Materials Science and Technology, Laboratory for Air Pollution/Environmental Technology, Duebendorf (Switzerland); Hammer, S. [Institut fuer Umweltphysik, Heidelberg Universitaet, Heidelberg (Germany); Forster, G.; Sturges, W.T. [School of Environmental Sciences, University of East Anglia, Norwich (United Kingdom)

    2013-05-16

    This work reassesses the global atmospheric budget of H2 with the TM5 model. The recent adjustment of the calibration scale for H2 translates into a change in the tropospheric burden. Furthermore, the ECMWF Reanalysis-Interim (ERA-Interim) data from the European Centre for Medium-Range Weather Forecasts (ECMWF) used in this study show slower vertical transport than the operational data used before. Consequently, more H2 is removed by deposition. The deposition parametrization is updated because significant deposition fluxes for snow, water, and vegetation surfaces were calculated in our previous study. Timescales of 1-2h are asserted for the transport of H2 through the canopies of densely vegetated regions. The global scale variability of H2 and {rho}({Delta}H2) is well represented by the updated model. H2 is slightly overestimated in the Southern Hemisphere because too little H2 is removed by dry deposition to rainforests and savannahs. The variability in H2 over Europe is further investigated using a high-resolution model subdomain. It is shown that discrepancies between the model and the observations are mainly caused by the finite model resolution. The tropospheric burden is estimated at 165{+-}8 Tg H2. The removal rates of H2 by deposition and photochemical oxidation are estimated at 53{+-}4 and 23{+-}2 Tg H2/yr, resulting in a tropospheric lifetime of 2.2{+-}0.2 year.

  7. Process for the production of heavy water by H2-methylamine isotopic exchange

    International Nuclear Information System (INIS)

    Briec, M.; Ravoire, J.; Rostaing, M.

    1977-01-01

    An isotopic exchange process for separating D 2 from H 2 is presented. The H 2 -monomethylamine system is studied on the laboratory scale (kinetics, H 2 solubility, thermal stability and solubility of the catalyst) and on the pilot plant scale (operating conditions and economics) [fr

  8. Overview of the Hydrogen Financial Analysis Scenario Tool (H2FAST); NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Melaina, Marc; Bush, Brian; Penev, Michael

    2015-05-12

    This presentation provides an introduction to the Hydrogen Financial Analysis Scenario Tool (H2FAST) and includes an overview of each of the three versions of H2FAST: the Web tool, the Excel spreadsheet version, and the beta version of the H2FAST Business Case Scenario tool.

  9. Rotational quenching of H2CO by molecular hydrogen–Suggestion ...

    Indian Academy of Sciences (India)

    Wiesenfeld and Faure investigated rotational quenching of H 2 CO by molecular hydrogen where they considered 40 rotational levels of o -H 2 CO and 41 rotational levels of p -H 2 CO. Data on energies of rotationallevels of the molecule are fundamental in the investigation. We have found that the sequence of levels ...

  10. CDNA encoding a polypeptide including a hevein sequence

    Science.gov (United States)

    Raikhel, Natasha V.; Broekaert, Willem F.; Chua, Nam-Hai; Kush, Anil

    1995-03-21

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  11. Effects of snake venom polypeptides on central nervous system.

    Science.gov (United States)

    Osipov, Alexey; Utkin, Yuri

    2012-12-01

    The nervous system is a primary target for animal venoms as the impairment of its function results in the fast and efficient immobilization or death of a prey. There are numerous evidences about effects of crude snake venoms or isolated toxins on peripheral nervous system. However, the data on their interactions with the central nervous system (CNS) are not abundant, as the blood-brain barrier (BBB) impedes penetration of these compounds into brain. This updated review presents the data about interaction of snake venom polypeptides with CNS. Such data will be described according to three main modes of interactions: - Direct in vivo interaction of CNS with venom polypeptides either capable to penetrate BBB or injected into the brain. - In vitro interactions of cell or sub-cellular fractions of CNS with crude venoms or purified toxins. - Indirect effects of snake venoms or their components on functioning of CNS under different conditions. Although the venom components penetrating BBB are not numerous, they seem to be the most suitable candidates for the leads in drug design. The compounds with other modes of action are more abundant and better studied, but the lack of the data about their ability to penetrate BBB may substantially aggravate the potentials for their medical perspectives. Nevertheless, many such compounds are used for research of CNS in vitro. These investigations may give invaluable information for understanding the molecular basis of CNS diseases and thus lay the basis for targeted drug design. This aspect also will be outlined in the review.

  12. cDNA encoding a polypeptide including a hevein sequence

    Energy Technology Data Exchange (ETDEWEB)

    Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

    2000-07-04

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  13. A new (multi-reference configuration interaction) potential energy surface for H2CO and preliminary studies of roaming

    Science.gov (United States)

    Wang, Xiaohong; Houston, Paul L.; Bowman, Joel M.

    2017-03-01

    We report a new global potential energy surface (PES) for H2CO, based on precise fitting of roughly 67 000 MRCI/cc-pVTZ energies. This PES describes the global minimum, the cis- and trans-HCOH isomers, and barriers relevant to isomerization, formation of the molecular (H2+CO) and radical (H+HCO) products, and the loose so-called roaming transition-state saddle point. The key features of the PES are reviewed and compared with a previous PES, denoted by PES04, based on five local fits that are `stitched' together by switching functions (Zhang et al. 2004 J. Phys. Chem. A 108, 8980-8986 (doi:10.1021/jp048339l)). Preliminary quasi-classical trajectory calculations are performed at the total energy of 36 233 cm-1 (103 kcal mol-1), relative to the H2CO global minimum, using the new PES, with a particular focus on roaming dynamics. When compared with the results from PES04, the new PES findings show similar rotational distributions, somewhat more roaming and substantially higher H2 vibrational excitation. This article is part of the themed issue 'Theoretical and computational studies of non-equilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces'.

  14. Methanogenic H2 syntrophy among thermophiles: a model of metabolism, adaptation and survival in the subsurface

    Science.gov (United States)

    Topcuoglu, B. D.; Stewart, L. C.; Butterfield, D. A.; Huber, J. A.; Holden, J. F.

    2016-12-01

    Approximately 1 giga ton (Gt, 1015 g) of CH4 is formed globally per year from H2, CO2 and acetate through methanogenesis, largely by methanogens growing in syntrophic association with anaerobic microbes that hydrolyze and ferment biopolymers. However, our understanding of methanogenesis in hydrothermal regions of the subseafloor and potential syntrophic methanogenesis at thermophilic temperatures (i.e., >50°C) is nascent. In this study, the growth of natural assemblages of thermophilic methanogens from Axial Seamount was primarily limited by H2 availability. Heterotrophs supported thermophilic methanogenesis by H2 syntrophy in microcosm incubations of hydrothermal fluids at 55°C and 80°C supplemented with tryptone only. Based on 16S rRNA gene sequencing, only heterotrophic archaea that produce H2, H2-consuming methanogens, and sulfate reducing archaea were found in 80°C tryptone microcosms from Marker 113 vent. No bacteria were found. In 55°C tryptone microcosms, sequences were found from H2-producing bacteria and H2-consuming methanogens and sulfate-reducing bacteria. In order to model the impact of H2 syntrophy at hyperthemophilic temperatures, a co-culture was established consisting of the H2-producing hyperthermophilic heterotroph Thermococcus paralvinellae and a H2-consuming hyperthermophilic methanogen Methanocaldococcus bathoardescens. When grown alone in a chemostat, the growth rates and steady-state cell concentrations of T. paralvinellae decreased significantly when a high H2 (70 µM) background was present. H2 inhibition was ameliorated by the production of formate, but in silico modeling suggests less energetic yield for the cells. H2 syntrophy relieved H2 inhibition for both the heterotroph and the methanogenic partners. The results demonstrate that thermophilic H2 syntrophy can support methanogenesis within natural microbial assemblages and may be an important alternative energy source for thermophilic autotrophs in marine geothermal environments.

  15. Comparative Ecology of H2 Cycling in Organotrophic and Phototrophic Ecosystems

    Science.gov (United States)

    Hoehler, Tori M.; Alperin, Marc J.; Albert, Daniel B.; Bebout, Brad M.; Martens, Christopher S.; DesMarais, David J.; DeVincenzi, Don (Technical Monitor)

    2001-01-01

    The simple biochemistry of H2 is critical to a large number of microbial processes, affecting the interaction of organisms with each other and with the environment. The sensitivity of these many processes to H2 can be described quantitatively, at a basic thermodynamic level. This shared dependence on H2 may provide a means for interpreting the ecology and system-level biogeochemistry of widely variant microbial ecosystems on a common (and quantitative) level. Understanding the factors that control H2 itself is a critical prerequisite. Here, we examine two ecosystems that vary widely with respect to H2 cycling. In anoxic, 'organotrophic' sediments from Cape Lookout Bight (North Carolina, USA), H2 partial pressures are strictly maintained at low, steady-state levels by H2-consuming organisms, in a fashion that can be quantitatively predicted by simple thermodynamic calculations. In phototrophic microbial mats from Baja, Mexico, H2 partial pressures are instead controlled by the activity of light-sensitive H2-producing organisms. In consequence, H2 partial pressures within the system fluctuate by orders of magnitude on hour-long time scales. The differences in H2 cycling subsequently impact H2-sensitive microbial processes, such as methanogenesis. For example, the presence of sulfate in the organotrophic system always yielded low levels of H2 that were inhibitory to methanogenesis; however, the elevated levels of H2 in the phototrophic system favored methane production at significant levels, even in the presence of high sulfate concentrations. The myriad of other H2-sensitive microbial processes are expected to exhibit similar behavior.

  16. D/H fractionation in the H2-H2O system at supercritical water conditions: Compositional and hydrogen bonding effects

    Science.gov (United States)

    Foustoukos, Dionysis I.; Mysen, Bjorn O.

    2012-06-01

    A series of experiments has been conducted in the H2-D2-D2O-H2O-Ti-TiO2 system at temperatures ranging from 300 to 800 °C and pressures between ∼0.3 and 1.3 GPa in a hydrothermal diamond anvil cell, utilizing Raman spectroscopy as a quantitative tool to explore the relative distribution of hydrogen and deuterium isotopologues of the H2 and H2O in supercritical fluids. In detail, H2O-D2O solutions (1:1) were reacted with Ti metal (3-9 h) in the diamond cell, leading to formation of H2, D2, HD, and HDO species through Ti oxidation and H-D isotope exchange reactions. Experimental results obtained in situ and at ambient conditions on quenched samples indicate significant differences from the theoretical estimates of the equilibrium thermodynamic properties of the H-D exchange reactions. In fact, the estimated enthalpy for the H2(aq)-D2(aq) disproportionation reaction (ΔHrxn) is about -3.4 kcal/mol, which differs greatly from the +0.16 kcal/mol predicted for the exchange reaction in the gas phase by statistical mechanics models. The exothermic behavior of the exchange reaction implies enhanced stability of H2 and D2 relative to HD. Accordingly, the significant energy difference of the internal H2(aq)-D2(aq)-HD(aq) equilibrium translates to strong differences of the fractionation effects between the H2O-H2 and D2O-D2 isotope exchange relationships. The D/H fractionation factors between H2O-H2(aq) and D2O-D2(aq) differ by 365‰ in the 600-800 °C temperature range, and are indicative of the greater effect of D2O contribution to the δD isotopic composition of supercritical fluids. The negative ΔHrxn values for the H2(aq)-D2(aq)-HD(aq) equilibrium and the apparent decrease of the equilibrium constant with increasing temperature might be because of differences of the Henry’s law constant between the H- and D-bearing species dissolved in supercritical aqueous solutions. Such effects may be attributed to the stronger hydrogen bonding in the O-H⋯O relative to the

  17. Profiling of cytosolic and mitochondrial H2O2 production using the H2O2-sensitive protein HyPer in LPS-induced microglia cells.

    Science.gov (United States)

    Park, Junghyung; Lee, Seunghoon; Lee, Hyun-Shik; Lee, Sang-Rae; Lee, Dong-Seok

    2017-07-27

    Dysregulation of the production of pro-inflammatory mediators in microglia exacerbates the pathologic process of neurodegenerative disease. ROS actively affect microglia activation by regulating transcription factors that control the expression of pro-inflammatory genes. However, accurate information regarding the function of ROS in different subcellular organelles has not yet been established. Here, we analyzed the pattern of cytosolic and mitochondrial H 2 O 2 formation in LPS-activated BV-2 microglia using the H 2 O 2- sensitive protein HyPer targeted to specific subcellular compartments. Our results show that from an early time, cytosolic H 2 O 2 started increasing constantly, whereas mitochondrial H 2 O 2 rapidly increased later. In addition, we found that MAPK affected cytosolic H 2 O 2 , but not mitochondrial H 2 O 2 . Consequently, our study provides the basic information about subcellular H 2 O 2 generation in activated microglia, and a useful tool for investigating molecular targets that can modulate neuroinflammatory responses. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. H2O2 levels in rainwater collected in south Florida and the Bahama Islands

    Science.gov (United States)

    Zika, R.; Saltzman, E.; Chameides, W. L.; Davis, D. D.

    1982-01-01

    Measurements of H2O2 in rainwater collected in Miami, Florida, and the Bahama Islands area indicate the presence of H2O2 concentration levels ranging from 100,000 to 700,000 M. No systematic trends in H2O2 concentration were observed during an individual storm, in marked contrast to the behavior of other anions for example, NO3(-), SO4(-2), and Cl(-). The data suggest that a substantial fraction of the H2O2 found in precipitation is generated by aqueous-phase reactions within the cloudwater rather than via rainout and washout of gaseous H2O2.

  19. Studies of valence-bond based quantum mechanical potential-energy surfaces. I. H2 + D2 exchange reaction. II. LiH + H → Li + H2 and LiH + D → LiD + H reactions

    International Nuclear Information System (INIS)

    Freihaut, B.H.

    1975-01-01

    The first phase of this investigation involved the construction of a perfect pairing valence-bond (VB) quantum mechanical potential-energy surfaces for the (H 2 D 2 ) system to compare its results for various geometries to the other prior formulations of such. A plausible four-body pathway for the H 2 --D 2 exchange reaction as shown by a semiempirical Huckel method was explored by the current valence-bond procedure. The second phase of the present investigation involves the formation of a VB based potential-energy surface for the LiH + H → Li + H 2 and LiH + D → LiD + H reaction systems for geometries compatible for a three-center reaction mechanism. No energy acceptable four-body reaction pathway was found for the H 2 --D 2 exchange system. Good agreement was demonstrated with previous ''ab initio'' configuration interaction (CI) studies for the various geometries tested. The square configuration for the H 4 system yielded the lowest barrier height of all the four-body geometries tested although it was still considerably higher than the experimental activation energy for the (H 2 ,D 2 ) system. The barrier height energy for the linear LiH--H configuration agreed well with the one previous work on this system. The barrier height for the LiH--H system increases as the Li--H--H bond angle decreases from 180 0 to 90 0 as well as the Li--H distance at the saddle point. The VB method used herein showed markedly good comparison with recent full CI calculations on the lithium-hydrogen system especially in view of the very limited basis set used in the VB procedure

  20. Polysulfides and products of H2S/S-nitrosoglutathione in comparison to H2S, glutathione and antioxidant Trolox are potent scavengers of superoxide anion radical and produce hydroxyl radical by decomposition of H2O2.

    Science.gov (United States)

    Misak, Anton; Grman, Marian; Bacova, Zuzana; Rezuchova, Ingeborg; Hudecova, Sona; Ondriasova, Elena; Krizanova, Olga; Brezova, Vlasta; Chovanec, Miroslav; Ondrias, Karol

    2018-06-01

    Exogenous and endogenously produced sulfide derivatives, such as H 2 S/HS - /S 2- , polysulfides and products of the H 2 S/S-nitrosoglutathione interaction (S/GSNO), affect numerous biological processes in which superoxide anion (O 2 - ) and hydroxyl (OH) radicals play an important role. Their cytoprotective-antioxidant and contrasting pro-oxidant-toxic effects have been reported. Therefore, the aim of our work was to contribute to resolving this apparent inconsistency by studying sulfide derivatives/free radical interactions and their consequent biological effects compared to the antioxidants glutathione (GSH) and Trolox. Using the electron paramagnetic resonance (EPR) spin trapping technique and O 2 - , we found that a polysulfide (Na 2 S 4 ) and S/GSNO were potent scavengers of O 2 - and cPTIO radicals compared to H 2 S (Na 2 S), GSH and Trolox, and S/GSNO scavenged the DEPMPO-OH radical. As detected by the EPR spectra of DEPMPO-OH, the formation of OH in physiological solution by S/GSNO was suggested. All the studied sulfide derivatives, but not Trolox or GSH, had a bell-shaped potency to decompose H 2 O 2 and produced OH in the following order: S/GSNO > Na 2 S 4  ≥ Na 2 S > GSH = Trolox = 0, but they scavenged OH at higher concentrations. In studies of the biological consequences of these sulfide derivatives/H 2 O 2 properties, we found the following: (i) S/GSNO alone and all sulfide derivatives in the presence of H 2 O 2 cleaved plasmid DNA; (ii) S/GSNO interfered with viral replication and consequently decreased the infectivity of viruses; (iii) the sulfide derivatives induced apoptosis in A2780 cells but inhibited apoptosis induced by H 2 O 2 ; and (iv) Na 2 S 4 modulated intracellular calcium in A87MG cells, which depended on the order of Na 2 S 4 /H 2 O 2 application. We suggest that the apparent inconsistency of the cytoprotective-antioxidant and contrasting pro-oxidant-toxic biological effects of sulfide derivatives results from their time

  1. Poisoning of Ni-Based anode for proton conducting SOFC by H2S, CO2, and H2O as fuel contaminants

    Science.gov (United States)

    Sun, Shichen; Awadallah, Osama; Cheng, Zhe

    2018-02-01

    It is well known that conventional solid oxide fuel cells (SOFCs) based on oxide ion conducting electrolyte (e.g., yttria-stabilized zirconia, YSZ) and nickel (Ni) - ceramic cermet anodes are susceptible to poisoning by trace amount of hydrogen sulfide (H2S) while not significantly impacted by the presence of carbon dioxide (CO2) and moisture (H2O) in the fuel stream unless under extreme operating conditions. In comparison, the impacts of H2S, CO2, and H2O on proton-conducting SOFCs remain largely unexplored. This study aims at revealing the poisoning behaviors caused by H2S, CO2, and H2O for proton-conducting SOFCs. Anode-supported proton-conducting SOFCs with BaZe0.1Ce0.7Y0.1Yb0.1O3 (BZCYYb) electrolyte and Ni-BZCYYb anode and La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) cathode as well as Ni-BZCYYb/BZCYYb/Ni-BZCYYb anode symmetrical cells were subjected to low ppm-level H2S or low percentage-level CO2 or H2O in the hydrogen fuel, and the responses in cell electrochemical behaviors were recorded. The results suggest that, contrary to conventional SOFCs that show sulfur poisoning and CO2 and H2O tolerance, such proton-conducting SOFCs with Ni-BZCYYb cermet anode seem to be poisoned by all three types of "contaminants". Beyond that, the implications of the experimental observations on understanding the fundamental mechanism of anode hydrogen electrochemical oxidation reaction in proton conducting SOFCs are also discussed.

  2. Comparative ecology of H2 cycling in sedimentary and phototrophic ecosystems

    Science.gov (United States)

    Hoehler, Tori M.; Albert, Daniel B.; Alperin, Marc J.; Bebout, Brad M.; Martens, Christopher S.; Des Marais, David J.

    2002-01-01

    The simple biochemistry of H2 is critical to a large number of microbial processes, affecting the interaction of organisms with each other and with the environment. The sensitivity of each of these processes to H2 can be described collectively, through the quantitative language of thermodynamics. A necessary prerequisite is to understand the factors that, in turn, control H2 partial pressures. These factors are assessed for two distinctly different ecosystems. In anoxic sediments from Cape Lookout Bight (North Carolina, USA), H2 partial pressures are strictly maintained at low, steady-state levels by H2-consuming organisms, in a fashion that can be quantitatively predicted by simple thermodynamic calculations. In phototrophic microbial mats from Baja California (Mexico), H2 partial pressures are controlled by the activity of light-sensitive H2-producing organisms, and consequently fluctuate over orders of magnitude on a daily basis. The differences in H2 cycling can subsequently impact any of the H2-sensitive microbial processes in these systems. In one example, methanogenesis in Cape Lookout Bight sediments is completely suppressed through the efficient consumption of H2 by sulfate-reducing bacteria; in contrast, elevated levels of H2 prevail in the producer-controlled phototrophic system, and methanogenesis occurs readily in the presence of 40 mM sulfate.

  3. Nanostructured Ti-catalyzed MgH2 for hydrogen storage.

    Science.gov (United States)

    Shao, H; Felderhoff, M; Schüth, F; Weidenthaler, C

    2011-06-10

    Nanocrystalline Ti-catalyzed MgH(2) can be prepared by a homogeneously catalyzed synthesis method. Comprehensive characterization of this sample and measurements of hydrogen storage properties are discussed and compared to a commercial MgH(2) sample. The catalyzed MgH(2) nanocrystalline sample consists of two MgH(2) phases-a tetrahedral β-MgH(2) phase and an orthorhombic high-pressure modification γ-MgH(2). Transmission electron microscopy was used for the observation of the morphology of the samples and to confirm the nanostructure. N(2) adsorption measurement shows a BET surface area of 108 m(2) g(-1) of the nanostructured material. This sample exhibits a hydrogen desorption temperature more than 130 °C lower compared to commercial MgH(2). After desorption, the catalyzed nanocrystalline sample absorbs hydrogen 40 times faster than commercial MgH(2) at 300 °C. Both the Ti catalyst and the nanocrystalline structure with correspondingly high surface area are thought to play important roles in the improvement of hydrogen storage properties. The desorption enthalpy and entropy values of the catalyzed MgH(2) nanocrystalline sample are 77.7 kJ mol(-1) H(2) and 138.3 J K(-1) mol(-1) H(2), respectively. Thermodynamic properties do not change with the nanostructure.

  4. Matrix infrared spectra and density functional calculations of the H2CCN and H2CNC radicals produced from CH3CN.

    Science.gov (United States)

    Cho, Han-Gook; Andrews, Lester

    2011-08-11

    The H(2)CCN and H(2)CNC radicals are observed in matrix IR spectra from acetonitrile exposed to radiation from laser ablation of transition metals, whereas cyc-H(2)CCN, another plausible isomer, is not. Density functional frequency calculations and D and (13)C isotopic substitutions substantiate the vibrational assignments. The cyano methyl radical converts to the 95 kJ/mol higher energy isocyano counterpart on uv photolysis. Computations show that the cyclic isomer is a shallow energy minimum between two transition states. Intrinsic reaction coordinate calculations indicate that conversion between the two products is feasible via the cyclic configuration.

  5. Quasi-classical trajectory study of the N(2D) + H2(X1ΣG+) → NH(X3Σ-) + H(2S) reaction based on an analytical potential energy surface.

    Science.gov (United States)

    Yang, Chuan-Lu; Wang, Li-Zhi; Wang, Mei-Shan; Ma, Xiao-Guang

    2013-01-10

    Using the multireference configuration interaction method with the Davidson correction and a large orbital basis set (aug-cc-pV5Z), we obtain an energy grid that includes 17,500 points for the construction of a new analytical potential energy surface (APES) for the N((2)D) + H(2)(X(1)Σ(g)(+)) → NH(X(3)Σ(-)) + H((2)S) reaction. The APES, which contains 145 parameters and is represented with a many-body expansion and a new switch function, is fitted from the ab initio energies using an adaptive nonlinear least-squares algorithm. The geometric characteristics of the reported APES in the literature and those of our APES are also compared. On the basis of the APES that we obtained, reaction cross sections are computed by means of quasi-classical trajectory calculations and compared with the experimental and theoretical values available in the literature.

  6. Thymus Polypeptide Preparation Tactivin Restores Learning and Memory in Thymectomied Rats.

    Science.gov (United States)

    Novoseletskaya, A V; Kiseleva, N M; Zimina, I V; Bystrova, O V; Belova, O V; Inozemtsev, A N; Arion, V Ya; Sergienko, V I

    2015-09-01

    We studied the effects of tactivin and splenic polypeptides on learning and memory of thymectomized animals. In 3-week rats, thymectomy blocked active avoidance conditioning. Injections of tactivin (0.5 mg/kg) during 1 month after surgery restored learning capacity; splenic polypeptides were ineffective.

  7. Biosynthesis of the neural cell adhesion molecule: characterization of polypeptide C

    DEFF Research Database (Denmark)

    Nybroe, O; Albrechtsen, M; Dahlin, J

    1985-01-01

    The biosynthesis of the neural cell adhesion molecule (N-CAM) was studied in primary cultures of rat cerebral glial cells, cerebellar granule neurons, and skeletal muscle cells. The three cell types produced different N-CAM polypeptide patterns. Glial cells synthesized a 135,000 Mr polypeptide B...

  8. Competition between surface adsorption and folding of fibril-forming polypeptides

    NARCIS (Netherlands)

    Ni, R.; Kleijn, J.M.; Cohen Stuart, M.A.; Bolhuis, P.G.

    2015-01-01

    Self-assembly of polypeptides into fibrillar structures can be initiated by planar surfaces that interact favorably with certain residues. Using a coarse-grained model, we systematically studied the folding and adsorption behavior of a ß -roll forming polypeptide. We find that there are two

  9. Competition between surface adsorption and folding of fibril-forming polypeptides

    NARCIS (Netherlands)

    Ni, R.; de Kleijn, M.; Abeln, S.; Cohen Stuart, M.A.; Bolhuis, P.G.

    2015-01-01

    Self-assembly of polypeptides into fibrillar structures can be initiated by planar surfaces that interact favorably with certain residues. Using a coarse-grained model, we systematically studied the folding and adsorption behavior of a β-roll forming polypeptide. We find that there are two different

  10. Synthesis of peptide-grafted comb polypeptides via polymerisation of NCA-peptides.

    Science.gov (United States)

    Enomoto, Hiroshi; Nottelet, Benjamin; Halifa, Soultan Al; Enjalbal, Christine; Dupré, Mathieu; Tailhades, Julien; Coudane, Jean; Subra, Gilles; Martinez, Jean; Amblard, Muriel

    2013-01-14

    A straightforward synthesis of comb-polypeptides of repeated peptide sequences was developed. These polypeptides were obtained by ROP of defined NCA without any post-polymerization grafting. The key to this strategy relies on the preparation of pure NCA bearing a peptide sequence on its side chain, by an original solid supported methodology.

  11. Ontogeny of αA and αB crystallin polypeptides during Rana temporaria lens development

    NARCIS (Netherlands)

    Brahma, S.K.; McDevitt, D.S.; DeFize, L.H.K.

    The ontogeny and localization of αA and αB polypeptide chains of α-crystallin were investigated in the developing lens of Rana temporaria, an anuran amphibian, using the indirect immunofluorescence staining method with heterologous antibodies directed against these two polypeptides. αA and αB

  12. High-performance liquid chromatography of rat and mouse islet polypeptides

    DEFF Research Database (Denmark)

    Linde, S; Hansen, B; Welinder, B S

    1990-01-01

    supported its suspected identity as methionine sulphoxide insulin II. We have examined the formation of Met-O derivatives of insulin II, glucagon and pancreatic polypeptide during sample preparation (Sep-Pak and Speed-Vac concentrating). The oxidation of methionine residues was found to depend very much......-O derivatives is important for the quantitation of methionine-containing polypeptides....

  13. Self-assembly of α-helical polypeptides driven by complex coacervation.

    Science.gov (United States)

    Priftis, Dimitrios; Leon, Lorraine; Song, Ziyuan; Perry, Sarah L; Margossian, Khatcher O; Tropnikova, Anna; Cheng, Jianjun; Tirrell, Matthew

    2015-09-14

    Reported is the ability of α-helical polypeptides to self-assemble with oppositely-charged polypeptides to form liquid complexes while maintaining their α-helical secondary structure. Coupling the α-helical polypeptide to a neutral, hydrophilic polymer and subsequent complexation enables the formation of nanoscale coacervate-core micelles. While previous reports on polypeptide complexation demonstrated a critical dependence of the nature of the complex (liquid versus solid) on chirality, the α-helical structure of the positively charged polypeptide prevents the formation of β-sheets, which would otherwise drive the assembly into a solid state, thereby, enabling coacervate formation between two chiral components. The higher charge density of the assembly, a result of the folding of the α-helical polypeptide, provides enhanced resistance to salts known to inhibit polypeptide complexation. The unique combination of properties of these materials can enhance the known potential of fluid polypeptide complexes for delivery of biologically relevant molecules. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Characterisation of the nascent polypeptide-associated complex in fission yeast

    DEFF Research Database (Denmark)

    Andersen, Katrine M; Semple, Colin A; Hartmann-Petersen, Rasmus

    2007-01-01

    The nascent polypeptide-associated complex (NAC) is an abundant and phylogenetically conserved protein complex. It is composed of two subunits and interacts with nascent polypeptide chains emerging from the ribosome. It has been proposed to protect the nascent chains from premature interaction...

  15. Competition between surface adsorption and folding of fibril-forming polypeptides

    NARCIS (Netherlands)

    Ni, R.; Kleijn, J.M.; Abeln, S.; Cohen Stuart, M.A.; Bolhuis, P.G.

    2015-01-01

    Self-assembly of polypeptides into fibrillar structures can be initiated by planar surfaces that interact favorably with certain residues. Using a coarse-grained model, we systematically studied the folding and adsorption behavior of a beta-roll forming polypeptide. We find that there are two

  16. A novel constrained H2 optimization algorithm for mechatronics design in flexure-linked biaxial gantry.

    Science.gov (United States)

    Ma, Jun; Chen, Si-Lu; Kamaldin, Nazir; Teo, Chek Sing; Tay, Arthur; Mamun, Abdullah Al; Tan, Kok Kiong

    2017-11-01

    The biaxial gantry is widely used in many industrial processes that require high precision Cartesian motion. The conventional rigid-link version suffers from breaking down of joints if any de-synchronization between the two carriages occurs. To prevent above potential risk, a flexure-linked biaxial gantry is designed to allow a small rotation angle of the cross-arm. Nevertheless, the chattering of control signals and inappropriate design of the flexure joint will possibly induce resonant modes of the end-effector. Thus, in this work, the design requirements in terms of tracking accuracy, biaxial synchronization, and resonant mode suppression are achieved by integrated optimization of the stiffness of flexures and PID controller parameters for a class of point-to-point reference trajectories with same dynamics but different steps. From here, an H 2 optimization problem with defined constraints is formulated, and an efficient iterative solver is proposed by hybridizing direct computation of constrained projection gradient and line search of optimal step. Comparative experimental results obtained on the testbed are presented to verify the effectiveness of the proposed method. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Experimental investigation of H2/D2 isotope separation by cryo-adsorption in metal-organic frameworks

    International Nuclear Information System (INIS)

    Teufel, Julia Sonja

    2012-01-01

    Light-gas isotopes differ in their adsorption behavior under cryogenic conditions in nanoporous materials due to their difference in zero-point energy. However, the applicability of these cryo-effects for the separation of isotope mixtures is still lacking an experimental proof. The current work describes the first experimentally obtained H 2 /D 2 selectivity values of nanoporous materials measured by applying isotope mixtures in low-temperature thermal desorption spectroscopy (TDS). The dissertation contains the following key points: 1) A proof of the experimental method, i.e. it is shown that TDS leads to reasonable selectivity values. 2) A series of small-pore MFU-4 derivatives (MOFs) is shown to separate isotope mixtures by quantum sieving, i.e. by the difference in the adsorption kinetics. The influence of the pore size on the selectivity is studied systematically for this series. 3) Two MOFs with pores much larger than the kinetic diameter of H 2 do not exhibit kinetic quantum sieving. However, if the MOFs are exposed to an isotope mixture, deuterium adsorbs preferentially at the adsorption sites with high heats of adsorption. According to the experimental results, these strong adsorption sites can be every selective for deuterium. On the basis of the experimentally obtained selectivity values, technical implementations for H 2 /D 2 light-gas isotope separation by cryo-adsorption are described.

  18. Factors affecting temporal H2S emission at construction and demolition (C&D) debris landfills.

    Science.gov (United States)

    Xu, Qiyong; Townsend, Timothy

    2014-02-01

    Odor problems associated with H2S emissions often result in odor complaints from nearby residents of C&D debris landfills, especially in the early morning. As part of a field study conducted on H2S removal ability using different cover materials, daily and seasonal H2S emissions through a soil cover layer were monitored at a C&D debris landfill to investigate factors affecting H2S emissions. H2S emission rates were not a constant, but varied seasonally, with an average emission rate of 4.67×10(-6)mgm(-2)s(-1). During a the 10-month field study, as the H2S concentration increased from 140ppm to about 3500ppm underneath the cover soil in the testing cell, H2S emissions ranged from zero to a maximum emission rate of 1.24×10(-5)mgm(-2)s(-1). Continuous emission monitoring indicated that H2S emissions even changed over time throughout the day, generally increasing from morning to afternoon, and were affected by soil moisture and temperature. Laboratory experiments were also conducted to investigate the effects of H2S concentration and cover soil moisture content on H2S emissions. The results showed that increased soil moisture reduced H2S emissions by retarding H2S migration through cover soil and dissolving H2S into soil water. The field study also indicated that due to atmospheric dispersion, high H2S emissions may not cause odor problems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Comparative analysis of expression of histone H2a genes in mouse

    Directory of Open Access Journals (Sweden)

    Tomaru Yasuhiro

    2005-08-01

    Full Text Available Abstract Background At least 18 replication-dependent histone H2a genes are distributed in 3 Hist gene clusters on different chromosomes of the mouse genome. In this analysis we designed specific PCR primers for each histone H2a transcript and studied the expression levels and patterns using quantitative RT-PCR (qRT-PCR. In addition, we compared histone H3 K9 acetylation levels in the promoter regions of H2a genes by ChIP (chromatin immunoprecipitation – quantitative PCR (qPCR analysis. Results RT-PCR analysis indicated that all 20 histone H2a genes assessed in this study are expressed. The replication-dependent histone H2a genes have different expression levels but similar expression patterns. Among the 20 histone H2a genes, the expression-level of H2afz, a replication-independent gene, was highest, and that of Hist1h2aa, a replication-dependent gene, was lowest. Among 18 replication-dependent H2a genes, the expression level of Hist3h2a was highest. The ChIP-qPCR analysis showed that histone H3 K9 acetylation levels in promoter regions of both H2afz and Hist3h2a are clearly higher than that in the promoter region of Hist1h2aa. The H3 K9 acetylation level in the promoter of Hist1h2aa is similar to that in the γ-satellite region. Conclusion These results strongly suggest that histone H3 K9 acetylation plays a role in the expression of histone genes.

  20. H2A/K pseudogene mutation may promote cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jisheng; Jing, Ruirui; Lv, Xin; Wang, Xiaoyue; Li, Junqiang; Li, Lin; Li, Cuiling; Wang, Daoguang; Bi, Baibing; Chen, Xinjun [Cancer Research Center, Shandong University School of Medicine, Jinan 250012 (China); Yang, Jing-Hua, E-mail: sdu_crc_group1@126.com [Cancer Research Center, Shandong University School of Medicine, Jinan 250012 (China); Department of Surgery, VA Boston Healthcare System, Boston University School of Medicine, Boston 510660, MA (United States)

    2016-05-15

    Highlights: • The mutant H2A/K pseudogene is active. • The mutant H2A/K pseudogene can promote cell proliferation. - Abstract: Little attention has been paid to the histone H2A/K pseudogene. Results from our laboratory showed that 7 of 10 kidney cancer patients carried a mutant H2A/K pseudogene; therefore, we were interested in determining the relationship between mutant H2A/K and cell proliferation. We used shotgun and label-free proteomics methods to study whether mutant H2A/K lncRNAs affected cell proliferation. Quantitative proteomic analysis indicated that the expression of mutant H2A/K lncRNAs resulted in the upregulation of many oncogenes, which promoted cell proliferation. Further interaction analyses revealed that a proliferating cell nuclear antigen (PCNA)-protein interaction network, with PCNA in the center, contributes to cell proliferation in cells expressing the mutant H2A/K lncRNAs. Western blotting confirmed the critical upregulation of PCNA by mutant H2A/K lncRNA expression. Finally, the promotion of cell proliferation by mutant H2A/K lncRNAs (C290T, C228A and A45G) was confirmed using cell proliferation assays. Although we did not determine the exact mechanism by which the oncogenes were upregulated by the mutant H2A/K lncRNAs, we confirmed that the mutant H2A/K lncRNAs promoted cell proliferation by upregulating PCNA and other oncogenes. The hypothesis that cell proliferation is promoted by the mutant H2A/K lncRNAs was supported by the protein expression and cell proliferation assay results. Therefore, mutant H2A/K lncRNAs may be a new factor in renal carcinogenesis.

  1. Differential regulation of TRPV1 channels by H2O2: implications for diabetic microvascular dysfunction

    Science.gov (United States)

    DelloStritto, Daniel J.; Connell, Patrick J.; Dick, Gregory M.; Fancher, Ibra S.; Klarich, Brittany; Fahmy, Joseph N.; Kang, Patrick T.; Chen, Yeong-Renn; Damron, Derek S.; Thodeti, Charles K.

    2016-01-01

    We demonstrated previously that TRPV1-dependent coupling of coronary blood flow (CBF) to metabolism is disrupted in diabetes. A critical amount of H2O2 contributes to CBF regulation; however, excessive H2O2 impairs responses. We sought to determine the extent to which differential regulation of TRPV1 by H2O2 modulates CBF and vascular reactivity in diabetes. We used contrast echocardiography to study TRPV1 knockout (V1KO), db/db diabetic, and wild type C57BKS/J (WT) mice. H2O2 dose-dependently increased CBF in WT mice, a response blocked by the TRPV1 antagonist SB366791. H2O2-induced vasodilation was significantly inhibited in db/db and V1KO mice. H2O2 caused robust SB366791-sensitive dilation in WT coronary microvessels; however, this response was attenuated in vessels from db/db and V1KO mice, suggesting H2O2-induced vasodilation occurs, in part, via TRPV1. Acute H2O2 exposure potentiated capsaicin-induced CBF responses and capsaicin-mediated vasodilation in WT mice, whereas prolonged luminal H2O2 exposure blunted capsaicin-induced vasodilation. Electrophysiology studies re-confirms acute H2O2 exposure activated TRPV1 in HEK293A and bovine aortic endothelial cells while establishing that H2O2 potentiate capsaicin-activated TRPV1 currents, whereas prolonged H2O2 exposure attenuated TRPV1 currents. Verification of H2O2-mediated activation of intrinsic TRPV1 specific currents were found in isolated mouse coronary endothelial cells from WT mice and decreased in endothelial cells from V1KO mice. These data suggest prolonged H2O2 exposure impairs TRPV1-dependent coronary vascular signaling. This may contribute to microvascular dysfunction and tissue perfusion deficits characteristic of diabetes. PMID:26907473

  2. Investigating H 2 Sorption in a Fluorinated Metal–Organic Framework with Small Pores Through Molecular Simulation and Inelastic Neutron Scattering

    KAUST Repository

    Forrest, Katherine A.

    2015-07-07

    © 2015 American Chemical Society. Simulations of H2 sorption were performed in a metal-organic framework (MOF) consisting of Zn2+ ions coordinated to 1,2,4-triazole and tetrafluoroterephthalate ligands (denoted [Zn(trz)(tftph)] in this work). The simulated H2 sorption isotherms reported in this work are consistent with the experimental data for the state points considered. The experimental H2 isosteric heat of adsorption (Qst) values for this MOF are approximately 8.0 kJ mol-1 for the considered loading range, which is in the proximity of those determined from simulation. The experimental inelastic neutron scattering (INS) spectra for H2 in [Zn(trz)(tftph)] reveal at least two peaks that occur at low energies, which corresponds to high barriers to rotation for the respective sites. The most favorable sorption site in the MOF was identified from the simulations as sorption in the vicinity of a metal-coordinated H2O molecule, an exposed fluorine atom, and a carboxylate oxygen atom in a confined region in the framework. Secondary sorption was observed between the fluorine atoms of adjacent tetrafluoroterephthalate ligands. The H2 molecule at the primary sorption site in [Zn(trz)(tftph)] exhibits a rotational barrier that exceeds that for most neutral MOFs with open-metal sites according to an empirical phenomenological model, and this was further validated by calculating the rotational potential energy surface for H2 at this site. (Figure Presented).

  3. The role of Golgi reassembly and stacking protein 65 phosphorylation in H2O2-induced cell death and Golgi morphological changes.

    Science.gov (United States)

    Ji, Guang; Zhang, Weiwei; Quan, Moyuan; Chen, Yang; Qu, Hui; Hu, Zhiping

    2016-12-01

    This study aimed to investigate the effects of H 2 O 2 -induced oxidative stress on cell viability and survival, as well as changes in the distribution of Golgi apparatus and in the level of Golgi reassembly and stacking protein 65 (GRASP65). Cell viability of cultured N2a cells treated with H 2 O 2 was measured by the MTT assay. Apoptosis was measured by flow cytometry analyses. Cells labeled by indirect immunofluorescence were observed under confocal microscope to detect any Golgi morphological alterations; electron microscopy of Golgi apparatus was also done. Expression of GRASP65 and phospho-GRASP65 was examined by immunoblotting. H 2 O 2 treatment reduced the cell viability and raised the cell mortality of N2a cells in a time-dependent manner. Notable changes were only observed in the distribution and morphology of Golgi apparatus at 6 h after H 2 O 2 treatment. The expression of GRASP65 showed no significant changes at different time points; the phosphorylated GRASP65 level was significantly increased after H 2 O 2 treatment, peaked at 3 h, and finally dropped at 6 h. Taken together, GRASP65 phosphorylation may have a critical role in inducing cell death at the early stage after H 2 O 2 treatment, while its role in H 2 O 2 -induced Golgi morphological changes may be complex.

  4. Ring-Opening Polymerization of N-Carboxyanhydrides for Preparation of Polypeptides and Polypeptide-Based Hybrid Materials with Various Molecular Architectures

    KAUST Repository

    Pahovnik, David

    2015-09-01

    Different synthetic approaches utilizing ring-opening polymerization of N-carboxyanhydrides for preparation of polypeptide and polypeptide-based hybrid materials with various molecular architectures are described. An overview of polymerization mechanisms using conventional (various amines) as well as some recently developed initiators (hexamethyldisilazane, N-heterocyclic persistent carbenes, etc.) is presented, and their benefits and drawbacks for preparation of polypeptides with well-defined chain lengths and chain-end functionality are discussed. Recent examples from literature are used to illustrate different possibilities for synthesis of pure polypeptide materials with different molecular architectures bearing various functional groups, which are introduced either by modification of amino acids, before they are transformed into corresponding Ncarboxyanhydrides, or by post-polymerization modifications using protective groups and/or orthogonal functional groups. Different approaches for preparation of polypeptide-based hybrid materials are discussed as well using examples from recent literature. Syntheses of simple block copolymers or copolymers with more complex molecular architectures (graft and star copolymers) as well as modifications of nanoparticles and other surfaces with polypeptides are described.

  5. Angular dependence of dissociative electron attachment topolyatomic molecules: application to the 2B1 metastable state of the H2Oand H2S anions

    Energy Technology Data Exchange (ETDEWEB)

    Haxton, Daniel J.; McCurdy, C. William; Rescigno, Thomas N.

    2006-01-12

    The angular dependence of dissociative electron attachment (DEA) to polyatomic targets is formulated in the local complex potential model, under the assumption that the axial recoil approximation describes the dissociation dynamics. An additional approximation, which is found to be valid in the case of H2O but not in the case of H2S, makes it possible to describe the angular dependence of DEA solely from an analysis of the fixed-nuclei entrance amplitude, without carrying out nuclear dynamics calculations. For H2S, the final-vibrational-state-specific angular dependence of DEA is obtained by incorporating the variation of the angular dependence of the entrance amplitude with nuclear geometry into the nuclear dynamics. Scattering calculations using the complex Kohn method and, for H2S, full quantum calculations of the nuclear dynamics using the Multi-Configuration Time-Dependent Hartree method, are performed.

  6. Gibbs free energy of reactions involving SiC, Si3N4, H2, and H2O as a function of temperature and pressure

    Science.gov (United States)

    Isham, M. A.

    1992-01-01

    Silicon carbide and silicon nitride are considered for application as structural materials and coating in advanced propulsion systems including nuclear thermal. Three-dimensional Gibbs free energy were constructed for reactions involving these materials in H2 and H2/H2O. Free energy plots are functions of temperature and pressure. Calculations used the definition of Gibbs free energy where the spontaneity of reactions is calculated as a function of temperature and pressure. Silicon carbide decomposes to Si and CH4 in pure H2 and forms a SiO2 scale in a wet atmosphere. Silicon nitride remains stable under all conditions. There was no apparent difference in reaction thermodynamics between ideal and Van der Waals treatment of gaseous species.

  7. Ab initio studies of O-2(-) (H2O)(n) and O-3(-) (H2O)(n) anionic molecular clusters, n

    DEFF Research Database (Denmark)

    Bork, Nicolai Christian; Kurten, T.; Enghoff, Martin Andreas Bødker

    2011-01-01

    that anionic O-2(-)(H2O)n and O-3(-)(H2O)n clusters are thermally stabilized at typical atmospheric conditions for at least n = 5. The first 4 water molecules are strongly bound to the anion due to delocalization of the excess charge while stabilization of more than 4 H2O is due to normal hydrogen bonding....... Although clustering up to 12 H2O, we find that the O-2 and O-3 anions retain at least ca. 80 % of the charge and are located at the surface of the cluster. The O-2(-) and O-3(-) speicies are thus accessible for further reactions. We consider the distributions of cluster sizes as function of altitude before...

  8. Ab initio studies of O2-(H2O)n and O3-(H2O)n anionic molecular clusters, n≤12

    DEFF Research Database (Denmark)

    Bork, Nicolai Christian; Kurtén, T.; Enghoff, Martin Andreas Bødker

    2011-01-01

    that anionic O2−(H2O)n and O3−(H2O)n clusters are thermally stabilized at typical atmospheric conditions for at least n = 5. The first 4 water molecules are strongly bound to the anion due to delocalization of the excess charge while stabilization of more than 4 H2O is due to normal hydrogen bonding. Although...... clustering up to 12 H2O, we find that the O2 and O3 anions retain at least ca. 80 % of the charge and are located at the surface of the cluster. The O2− and O3− speicies are thus accessible for further reactions. Finally, the thermodynamics of a few relevant cluster reactions are considered....

  9. Long-term bio-H2 and bio-CH4 production from food waste in a continuous two-stage system: Energy efficiency and conversion pathways.

    Science.gov (United States)

    Algapani, Dalal E; Qiao, Wei; di Pumpo, Francesca; Bianchi, David; Wandera, Simon M; Adani, Fabrizio; Dong, Renjie

    2018-01-01

    Anaerobic digestion is a well-established technology for treating organic waste, but it is still under challenge for food waste due to process stability problems. In this work, continuous H 2 and CH 4 production from canteen food waste (FW) in a two-stage system were successfully established by optimizing process parameters. The optimal hydraulic retention time was 5d for H 2 and 15d for CH 4 . Overall, around 59% of the total COD in FW was converted into H 2 (4%) and into CH 4 (55%). The fluctuations of FW characteristics did not significantly affect process performance. From the energy point view, the H 2 reactor contributed much less than the methane reactor to total energy balance, but it played a key role in maintaining the stability of anaerobic treatment of food waste. Microbial characterization indicated that methane formation was through syntrophic acetate oxidation combined with hydrogenotrophic methanogenesis pathway. Copyright © 2017. Published by Elsevier Ltd.

  10. Crystal structure of strontium aqua(ethylenediaminetetraacetato)cobaltate(II) tetrahydrate Sr[CoEdta(H2O)] · 4H2O

    International Nuclear Information System (INIS)

    Zasurskaya, L.A.; Polynova, T.N.; Polyakova, I.N.; Sergienko, V.S.; Poznyak, A.L.

    2001-01-01

    The complex Sr[Co II Edta] · 5H 2 O (I) (where Edta 4- is the ethylenediaminetetraacetate ion) has been synthesized. The crystal structure of this compound is determined by X-ray diffraction. Crystals are monoclinic, a = 7.906(2) A, b = 12.768(2) A, c = 18.254(3) A, β = 95.30(3) deg., V 1834.8 A 3 , space group P2 1 /n, Z = 4, and R = 0.036. The structure is built up of the binuclear complex fragments {Sr(H 2 O) 3 [CoEdta(H 2 O)]}, which consist of the anionic [CoEdta(H 2 O)] 2- and cationic [Sr(H 2 O) 3 ] 2+ units linked by the Sr-O bonds into a three-dimensional framework. The coordination polyhedra of the Co and Sr atoms are mono- and bicapped trigonal prisms. The coordination sphere of the Co atom (the coordination number is equal to 6 + 1) involves six donor atoms (2N and 4O) of the Edta 4- ligand and the O w atom of water molecule. One of the Co-O distances (2.718 A) is considerably longer than the other Co-O lig distances (2.092-2.190 A) and the Co-O w (1) distance (2.079 A). The Sr coordination polyhedron (the coordination number is eight) contains three water molecules, three carbonyl O atoms of the three different anionic complexes, and two O atoms of one acetate group of the fourth anionic complex. The Sr-O distances fall in the range 2.535-2.674 A. The structural formula of the compound is {Sr(H 2 O) 3 [CoEdta(H 2 O)]} 3∞ · H 2 O

  11. First results of ISO-SWS observations of Saturn : Detection of CO2, CH3C2H, C4H2 and tropospheric H2O

    NARCIS (Netherlands)

    de Graauw, Th.; Feuchtgruber, H.; Bezard, B.; Drossart, P.; Encrenaz, T.; Beintema, D. A.; Griffin, M.; Heras, A.; Kessler, M.; Leech, K.; Lellouch, E.; Morris, P.; Roelfsema, P. R.; Roos-Serote, M.; Salama, A.; Vandenbussche, B.; Valentijn, E. A.; Davis, G. R.; Naylor, D. A.

    The spectrum of Saturn has been recorded between 4.5 and 16.0 mu m with the grating mode of the Short-Wavelength Spectrometer (SWS) of ISO. The resolving power is 1500. The main results of this observation are (1) the detection of CO2 CH3C2H and C4H2 in the stratosphere and (2) the detection of H2O

  12. Inhibition of gastric inhibitory polypeptide signaling prevents obesity

    DEFF Research Database (Denmark)

    Miyawaki, Kazumasa; Yamada, Yuichiro; Ban, Nobuhiro

    2002-01-01

    Secretion of gastric inhibitory polypeptide (GIP), a duodenal hormone, is primarily induced by absorption of ingested fat. Here we describe a novel pathway of obesity promotion via GIP. Wild-type mice fed a high-fat diet exhibited both hypersecretion of GIP and extreme visceral and subcutaneous fat...... deposition with insulin resistance. In contrast, mice lacking the GIP receptor (Gipr(-/-)) fed a high-fat diet were clearly protected from both the obesity and the insulin resistance. Moreover, double-homozygous mice (Gipr(-/-), Lep(ob)/Lep(ob)) generated by crossbreeding Gipr(-/-) and obese ob/ob (Lep......(ob)/Lep(ob)) mice gained less weight and had lower adiposity than Lep(ob)/Lep(ob) mice. The Gipr(-/-) mice had a lower respiratory quotient and used fat as the preferred energy substrate, and were thus resistant to obesity. Therefore, GIP directly links overnutrition to obesity and it is a potential target for anti-obesity...

  13. Effect of H2O2 on the corrosion behavior of 304L stainless steel

    International Nuclear Information System (INIS)

    Song, Taek Ho

    1994-02-01

    In connection with the safe storage of high level nuclear waste, effect of H 2 O 2 on the corrosion behavior of 304L stainless steel was examined. Open circuit potentials and polarization curves were measured with and without H 2 O 2 . The experimental results show that H 2 O 2 increased corrosion potential and decreased pitting potential. The passive range, therefore, decreased as H 2 O 2 concentration increased, indicating that pitting resistance was decreased by the existence of H 2 O 2 in the electrolyte. These effects of H 2 O 2 on corrosion of 304L stainless steel are considered to be similar to those of γ-irradiation. To compare the effects of H 2 O 2 with those of O 2 , cathodic and anodic polarization curves were made in three types of electrolyte such as aerated, deaerated, and stirred electrolyte. The experimental results show that the effects of H 2 O 2 on the corrosion behavior were very similar to those of O 2 such as increase of corrosion potential, decrease of pitting resistance, and increase of repassivation potential. Further, H 2 O 2 played much greater role in controlling cathodic reaction rate in neutral water environment. In acid and alkaline media, potential shifts by H 2 O 2 were restricted by the large current density of proton reduction and by the le Chatelier's principle respectively

  14. Thermal Reactions of H2O2 on Icy Satellites and Small Bodies: Descent with Modification?

    Science.gov (United States)

    Hudson, Reggie L.; Loeffler, Mark J.

    2012-01-01

    Magnetospheric radiation drives surface and near-surface chemistry on Europa, but below a few meters Europa's chemistry is hidden from direct observation . As an example, surface radiation chemistry converts H2O and SO2 into H2O2 and (SO4)(sup 2-), respectively, and these species will be transported downward for possible thermally-driven reactions. However, while the infrared spectra and radiation chemistry of H2O2-containing ices are well documented, this molecule's thermally-induced solid-phase chemistry has seldom been studied. Here we report new results on thermal reactions in H2O + H2O2 + SO2 ices at 50 - 130 K. As an example of our results, we find that warming H2O + H2O2 + SO2 ices promotes SO2 oxidation to (SO4)(sup 2-). These results have implications for the survival of H2O2 as it descends, with modification, towards a subsurface ocean on Europa. We suspect that such redox chemistry may explain some of the observations related to the presence and distribution of H2O2 across Europa's surface as well as the lack of H2O2 on Ganymede and Callisto.

  15. Histone H2AX phosphorylation is associated with most meiotic events in grasshopper.

    Science.gov (United States)

    Cabrero, J; Teruel, M; Carmona, F D; Camacho, J P M

    2007-01-01

    It is widely accepted that the H2AX histone in its phosphorylated form (gamma-H2AX) is related to the repair of DNA double-strand breaks (DSBs). In several organisms, gamma-H2AX presence has been demonstrated in meiotic processes such as recombination and sex chromosome inactivation during prophase I (from leptotene to pachytene). To test whether gamma-H2AX is present beyond pachytene, we have analysed the complete sequence of changes in H2AX phosphorylation during meiosis in grasshopper, a model organism for meiotic studies at the cytological level. We show the presence of phosphorylated H2AX during most of meiosis, with the exception only of diplotene and the end of each meiotic division. During the first meiotic division, gamma-H2AX is associated with i) recombination, as deduced from its presence in leptotene-zygotene over all chromosome length, ii) X chromosome inactivation, since at pachytene gamma-H2AX is present in the X chromosome only, and iii) chromosome segregation, as deduced from gamma-H2AX presence in centromere regions at first metaphase-anaphase. During second meiotic division, gamma-H2AX was very abundant at most chromosome lengths from metaphase to telophase, suggesting its possible association with the maintenance of chromosome condensation and segregation. Copyright 2007 S. Karger AG, Basel.

  16. Histone H2B mono-ubiquitylation maintains genomic integrity at stalled replication forks

    Science.gov (United States)

    Northam, Matthew R.; Trujillo, Kelly M.

    2016-01-01

    Histone modifications play an important role in regulating access to DNA for transcription, DNA repair and DNA replication. A central player in these events is the mono-ubiquitylation of histone H2B (H2Bub1), which has been shown to regulate nucleosome dynamics. Previously, it was shown that H2Bub1 was important for nucleosome assembly onto nascent DNA at active replication forks. In the absence of H2Bub1, incomplete chromatin structures resulted in several replication defects. Here, we report new evidence, which shows that loss of H2Bub1 contributes to genomic instability in yeast. Specifically, we demonstrate that H2Bub1-deficient yeast accumulate mutations at a high frequency under conditions of replicative stress. This phenotype is due to an aberrant DNA Damage Tolerance (DDT) response upon fork stalling. We show that H2Bub1 normally functions to promote error-free translesion synthesis (TLS) mediated by DNA polymerase eta (Polη). Without H2Bub1, DNA polymerase zeta (Polζ) is responsible for a highly mutagenic alternative mechanism. While H2Bub1 does not appear to regulate other DDT pathways, error-free DDT mechanisms are employed by H2Bub1-deficient cells as another means for survival. However, in these instances, the anti-recombinase, Srs2, is essential to prevent the accumulation of toxic HR intermediates that arise in an unconstrained chromatin environment. PMID:27458205

  17. Characterization of the UV-crosslinked heterodimer of histones H2B and H4

    International Nuclear Information System (INIS)

    Johnson, E.R.; Brown, D.M.; DeLange, R.J.

    1986-01-01

    At relatively high salt concentrations (1.2 M), histone 2B (H2B) and histone 4 (H4) can be covalently crosslinked by irradiation with ultraviolet light to yield a mixture of the three possible dimers: H2B-H2B, H4-H4, and H2B-H4. The formation of the H2B-H4 heterodimer was found to be favored at lower histone concentrations (> 90% H2B-H4 at 0.1 mg/ml total histone protein). CNBr cleavage of the H2B-H4 dimer produced three fragments which were separated by reverse phase HPLC. These fragments were identified by amino acid compositional analysis to be H4(85-102), H2B(62-125), and the crosslinked N-terminal regions H2B(1-59)-H4(1-84). Amino acid sequence analysis of the crosslinked fragment indicated that tyrosine-40 of H2B is likely involved in the covalent crosslinkage which joins the histone monomers to form the heterodimer

  18. Adsorption of H2O, H2, O2, CO, NO, and CO2 on graphene/g-C3N4 nanocomposite investigated by density functional theory

    Science.gov (United States)

    Wu, Hong-Zhang; Bandaru, Sateesh; Liu, Jin; Li, Li-Li; Wang, Zhenling

    2018-02-01

    Motivated by the photocatalytic reactions of small molecules on g-C3N4 by these insights, we sought to explore the adsorption of H2O and CO2 molecules on the graphene side and H2O, H2, O2, CO, NO, and CO2 molecules on the g-C3N4 side of hybrid g-C3N4/graphene nanocomposite using first-principles calculations. The atomic structure and electronic properties of hybrid g-C3N4/graphene nanocomposite is explored. The adsorption of small molecules on graphene/g-C3N4 nanocomposite is thoroughly investigated. The computational studies revels that all small molecules on graphene/g-C3N4 nanocomposite are the physisorption. The adsorption characteristics of H2O and CO2 molecules on the graphene side are similar to that on graphene. The adsorption of H2O, H2, O2, CO, NO, and CO2 molecules on the g-C3N4 side always leads to a buckle structure of graphene/g-C3N4 nanocomposite. Graphene as a substrate can significantly relax the buckle degree of g-C3N4 in g-C3N4/graphene nanocomposite.

  19. The structure of H2TiO3-a short discussion on "Lithium recovery from salt lake brine by H2TiO3".

    Science.gov (United States)

    Yu, Cheng-Long; Wang, Fei; Cao, Shu-Yao; Gao, Dan-Peng; Hui, Huai-Bing; Guo, Ying-Yan; Wang, Dao-Yi

    2015-09-21

    A short discussion on the structure of H2TiO3 presented in the article entitled Lithium recovery from salt lake brine by H2TiO3 (R. Chitrakar, Y. Makita, K. Ooi and A. Sonoda, Dalton Trans., 2014, 43, 8933) is presented. In our opinion, it is not correct to identify the phase of H2TiO3 as monoclinic. The XRD pattern of H2TiO3 differs substantially from that of Li2TiO3. XRD pattern simulation shows that the peak (1[combining macron]33) and the peak (2[combining macron]06) cannot be fully collapsed or substantially decrease in intensity by substitution of Li(+) with H(+) if H2TiO3 shares a similar space group and lattice parameters with Li2TiO3. A direct verification of a similar structure by N. V. Tarakina and co-workers may aid the confirmation of the structure. The layered double hydroxide type with the 3R1 sequence of oxygen layers is more reasonable for H2TiO3 and can be described as a stacking of charge-neutral metal oxyhydroxide slabs [(OH)2OTi2O(OH)2].

  20. Spectroscopic Properties and Potential Energy Surfaces for Curium Hydrides: CmH2, CmH2+, CmH, and CmH+

    Science.gov (United States)

    Balasubramanian, K.; Cao, Zhiji

    2009-09-01

    A relativistic complete active space multiconfigurational self-consistent field followed by multireference singles + doubles configuration interaction computations are carried out on the potential energy surfaces of electronic states of CmH2 and CmH2+ for the insertion reaction of Cm and Cm+ into H2. We have also carried out corresponding computations on several electronic states of CmH and CmH+. Moreover, multireference relativistic configuration interaction computations including spin-orbit coupling were carried out on 75 electronic states of CmH+, which were found to be below the 45 000 cm-1 region. We have computed the first ionization energy of Cm as 5.94 eV in excellent agreement with experimental value of 5.99 eV. Our computations reveal barriers for the insertion of Cm and Cm+ in their ground electronic states into H2, but once the barriers are surmounted, both Cm + H2 and Cm+ + H2 form stable products. The potential energy curves of CmH and CmH+ reveal the existence of several low-lying open-shell excited states with varied Λ quantum numbers and spin multiplicities. The excited states of these species exhibit intermediate coupling, although the spin-orbit splittings of the 9Σ- and 8Σ- ground states of CmH and CmH+ are small, exhibiting nearly inverted multiplets.

  1. Impact of High Glucose and Proteasome Inhibitor MG132 on Histone H2A and H2B Ubiquitination in Rat Glomerular Mesangial Cells

    Directory of Open Access Journals (Sweden)

    Chenlin Gao

    2013-01-01

    Full Text Available Background. Hyperglycemia plays a pivotal role in the development of diabetic nephropathy (DN and may be related to epigenetic metabolic memory. One of the most crucial epigenetic mechanisms is histone modification, which is associated with the expression of a fibrosis factor in vascular injury. Aim .In this study, we investigated the ubiquitination of histones H2A and H2B to explore the epigenetic mechanisms of DN. Materials and Methods. The GMCs were cultured as follows: normal group, high glucose group, mannitol group, and intervention group. After 12 hr, 24 hr, and 48 hr, histones ubiquitination, transforming growth factor-β (TGF-β, and fibronectin (FN were measured using WB, RT-PCR, and IF. Result. High glucose can induce the upregulation of FN. H2A ubiquitination in GMCs increased in high glucose group (P<0.01, whereas it decreased significantly in intervention group (P<0.05. In contrast, H2B ubiquitination decreased with an increasing concentration of glucose, but it was recovered in the intervention group (P<0.05. Expression of TGF-β changed in response to abnormal histone ubiquitination. Conclusions. The high glucose may induce H2A ubiquitination and reduce H2B ubiquitination in GMCs. The changes of histone ubiquitination may be due in part to DN by activating TGF-β signaling pathway.

  2. Spectroscopic properties and potential energy surfaces for curium hydrides: CmH(2), CmH(2)(+), CmH, and CmH(+).

    Science.gov (United States)

    Balasubramanian, K; Cao, Zhiji

    2009-11-12

    A relativistic complete active space multiconfigurational self-consistent field followed by multireference singles + doubles configuration interaction computations are carried out on the potential energy surfaces of electronic states of CmH(2) and CmH(2)(+) for the insertion reaction of Cm and Cm(+) into H(2). We have also carried out corresponding computations on several electronic states of CmH and CmH(+). Moreover, multireference relativistic configuration interaction computations including spin-orbit coupling were carried out on 75 electronic states of CmH(+), which were found to be below the 45 000 cm(-1) region. We have computed the first ionization energy of Cm as 5.94 eV in excellent agreement with experimental value of 5.99 eV. Our computations reveal barriers for the insertion of Cm and Cm(+) in their ground electronic states into H(2), but once the barriers are surmounted, both Cm + H(2) and Cm(+) + H(2) form stable products. The potential energy curves of CmH and CmH(+) reveal the existence of several low-lying open-shell excited states with varied Lambda quantum numbers and spin multiplicities. The excited states of these species exhibit intermediate coupling, although the spin-orbit splittings of the (9)Sigma(-) and (8)Sigma(-) ground states of CmH and CmH(+) are small, exhibiting nearly inverted multiplets.

  3. Rate constant for the H˙ + H2O → ˙OH + H2 reaction at elevated temperatures measured by pulse radiolysis.

    Science.gov (United States)

    Muroya, Y; Yamashita, S; Lertnaisat, P; Sanguanmith, S; Meesungnoen, J; Jay-Gerin, J-P; Katsumura, Y

    2017-11-22

    Maintaining the structural integrity of materials in nuclear power plants is an essential issue associated with safe operation. Hydrogen (H 2 ) addition or injection to coolants is a powerful technique that has been widely applied such that the reducing conditions in the coolant water avoid corrosion and stress corrosion cracking (SCC). Because the radiation-induced reaction of ˙OH + H 2 → H˙ + H 2 O plays a crucial role in these systems, the rate constant has been measured at operation temperatures of the reactors (285-300 °C) by pulse radiolysis, generating sufficient data for analysis. The reverse reaction H˙ + H 2 O → ˙OH + H 2 is negligibly slow at ambient temperature; however, it accelerates considerably quickly at elevated temperatures. Although the reverse reaction reduces the effectiveness of H 2 addition, reliable rate constants have not yet been measured. In this study, the rate constants have been determined in a temperature range of 250-350 °C by pulse radiolysis in an aqueous I - solution.

  4. Corrosion of Fe-(9~37 wt. %Cr Alloys at 700–800 °C in (N2, H2O, H2S-Mixed Gas

    Directory of Open Access Journals (Sweden)

    Min Jung Kim

    2016-11-01

    Full Text Available Fe-(9, 19, 28, 37 wt. %Cr alloys were corroded at 700 and 800 °C for 70 h under 1 atm of N2, 1 atm of N2/3.2%H2O mixed gas, and 1 atm of N2/3.1%H2O/2.42%H2S mixed gas. In this gas composition order, the corrosion rate of Fe-9Cr alloy rapidly increased. Fe-9Cr alloy was always non-protective. In contrast, Fe-(19, 28, 37 wt. %Cr alloys were protective in N2 and N2/3.2%H2O mixed gas because of the formation of the Cr2O3 layer. They, however, became nonprotective in N2/3.1%H2O/2.42%H2S mixed gas because sulfidation dominated to form the outer FeS layer and the inner Cr2S3 layer containing some FeCr2S4.

  5. Ce2(SO4)3-H2SO4-(NH4)2SO4-H2O system at 20 deg C

    International Nuclear Information System (INIS)

    Belokoskov, V.I.; Skovorodskaya, V.P.; Trofimov, G.V.; Spasibenko, T.P.

    1978-01-01

    The solubility of cerium sulfate in H 2 SO 4 was determined for an H 2 SO 4 concentration from 50 to 500 g/l and for an (NH 4 ) 2 SO 4 concentration from 0 to 400 g/l. It has been established that, at 20 deg C, in the examined range of H 2 SO 4 and (NH 4 ) 2 SO 4 concentrations there is a single solid phase in equilibrium with the saturated solution: binary sulfate of cerium and ammonium of Ce 2 (SO 4 ) 3 x(NH 4 ) 2 SO 4 x2H 2 O. The solubility of the binary salt for an H 2 SO 4 concentration of 300 to 500 g/l is 0.01 to 0.03% Ce 2 (SO 4 ) 3 . The ammonium sulfate concentration changing from 100 to 400 g/l produces practically no effect on the solubility. For an H 2 SO 4 concentration below 250 g/l, the solubility of the binary salt increases up to 0.12-O.14%, and the effect of ammonium sulfate on the solubility of the dihydrate becomes pronounced

  6. Histone H2AX is a critical factor for cellular protection against DNA alkylating agents.

    Science.gov (United States)

    Meador, J A; Zhao, M; Su, Y; Narayan, G; Geard, C R; Balajee, A S

    2008-09-25

    Histone H2A variant H2AX is a dose-dependent suppressor of oncogenic chromosome translocations. H2AX participates in DNA double-strand break repair, but its role in other DNA repair pathways is not known. In this study, role of H2AX in cellular response to alkylation DNA damage was investigated. Cellular sensitivity to two monofunctional alkylating agents (methyl methane sulfonate and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)) was dependent on H2AX dosage, and H2AX null cells were more sensitive than heterozygous cells. In contrast to wild-type cells, H2AX-deficient cells displayed extensive apoptotic death due to a lack of cell-cycle arrest at G(2)/M phase. Lack of G(2)/M checkpoint in H2AX null cells correlated well with increased mitotic irregularities involving anaphase bridges and gross chromosomal instability. Observation of elevated poly(ADP) ribose polymerase 1 (PARP-1) cleavage suggests that MNNG-induced apoptosis occurs by PARP-1-dependent manner in H2AX-deficient cells. Consistent with this, increased activities of PARP and poly(ADP) ribose (PAR) polymer synthesis were detected in both H2AX heterozygous and null cells. Further, we demonstrate that the increased PAR synthesis and apoptotic death induced by MNNG in H2AX-deficient cells are due to impaired activation of mitogen-activated protein kinase pathway. Collectively, our novel study demonstrates that H2AX, similar to PARP-1, confers cellular protection against alkylation-induced DNA damage. Therefore, targeting either PARP-1 or histone H2AX may provide an effective way of maximizing the chemotherapeutic value of alkylating agents for cancer treatment.

  7. The Role of Peroxiredoxins in the Transduction of H2O2 Signals.

    Science.gov (United States)

    Rhee, Sue Goo; Woo, Hyun Ae; Kang, Dongmin

    2018-03-01

    Hydrogen peroxide (H 2 O 2 ) is produced on stimulation of many cell surface receptors and serves as an intracellular messenger in the regulation of diverse physiological events, mostly by oxidizing cysteine residues of effector proteins. Mammalian cells express multiple H 2 O 2 -eliminating enzymes, including catalase, glutathione peroxidase (GPx), and peroxiredoxin (Prx). A conserved cysteine in Prx family members is the site of oxidation by H 2 O 2 . Peroxiredoxins possess a high-affinity binding site for H 2 O 2 that is lacking in catalase and GPx and which renders the catalytic cysteine highly susceptible to oxidation, with a rate constant several orders of magnitude greater than that for oxidation of cysteine in most H 2 O 2 effector proteins. Moreover, Prxs are abundant and present in all subcellular compartments. The cysteines of most H 2 O 2 effectors are therefore at a competitive disadvantage for reaction with H 2 O 2 . Recent Advances: Here we review intracellular sources of H 2 O 2 as well as H 2 O 2 target proteins classified according to biochemical and cellular function. We then highlight two strategies implemented by cells to overcome the kinetic disadvantage of most target proteins with regard to H 2 O 2 -mediated oxidation: transient inactivation of local Prx molecules via phosphorylation, and indirect oxidation of target cysteines via oxidized Prx. Critical Issues and Future Directions: Recent studies suggest that only a small fraction of the total pools of Prxs and H 2 O 2 effector proteins localized in specific subcellular compartments participates in H 2 O 2 signaling. Development of sensitive tools to selectively detect phosphorylated Prxs and oxidized effector proteins is needed to provide further insight into H 2 O 2 signaling. Antioxid. Redox Signal. 28, 537-557.

  8. Crystal structures of hydrates of simple inorganic salts. III. Water-rich aluminium halide hydrates: AlCl3 · 15H2O, AlBr3 · 15H2O, AlI3 · 15H2O, AlI3 · 17H2O and AlBr3 · 9H2O.

    Science.gov (United States)

    Schmidt, Horst; Hennings, Erik; Voigt, Wolfgang

    2014-09-01

    Water-rich aluminium halide hydrate structures are not known in the literature. The highest known water content per Al atom is nine for the perchlorate and fluoride. The nonahydrate of aluminium bromide, stable pentadecahydrates of aluminium chloride, bromide and iodide, and a metastable heptadecahydrate of the iodide have now been crystallized from low-temperature solutions. The structures of these hydrates were determined and are discussed in terms of the development of cation hydration spheres. The pentadecahydrate of the chloride and bromide are isostructural. In AlI(3) · 15H2O, half of the Al(3+) cations are surrounded by two complete hydration spheres, with six H2O in the primary and 12 in the secondary. For the heptadecahydrate of aluminium iodide, this hydration was found for every Al(3+).

  9. Genetic code redundancy and its influence on the encoded polypeptides

    Directory of Open Access Journals (Sweden)

    Paige S Spencer

    2012-04-01

    Full Text Available The genetic code is said to be redundant in that the same amino acid residue can be encoded by multiple, so-called synonymous, codons. If all properties of synonymous codons were entirely equivalent, one would expect that they would be equally distributed along protein coding sequences. However, many studies over the last three decades have demonstrated that their distribution is not entirely random. It has been postulated that certain codons may be translated by the ribosome faster than others and thus their non-random distribution dictates how fast the ribosome moves along particular segments of the mRNA. The reasons behind such segmental variability in the rates of protein synthesis, and thus polypeptide emergence from the ribosome, have been explored by theoretical and experimental approaches. Predictions of the relative rates at which particular codons are translated and their impact on the nascent chain have not arrived at unequivocal conclusions. This is probably due, at least in part, to variation in the basis for classification of codons as “fast” or “slow”, as well as variability in the number and types of genes and proteins analyzed. Recent methodological advances have allowed nucleotide-resolution studies of ribosome residency times in entire transcriptomes, which confirm the non-uniform movement of ribosomes along mRNAs and shed light on the actual determinants of rate control. Moreover, experiments have begun to emerge that systematically examine the influence of variations in ribosomal movement and the fate of the emerging polypeptide chain.

  10. GENETIC CODE REDUNDANCY AND ITS INFLUENCE ON THE ENCODED POLYPEPTIDES

    Directory of Open Access Journals (Sweden)

    Paige S. Spencer

    2012-04-01

    Full Text Available The genetic code is said to be redundant in that the same amino acid residue can be encoded by multiple, so-called synonymous, codons. If all properties of synonymous codons were entirely equivalent, one would expect that they would be equally distributed along protein coding sequences. However, many studies over the last three decades have demonstrated that their distribution is not entirely random. It has been postulated that certain codons may be translated by the ribosome faster than others and thus their non-random distribution dictates how fast the ribosome moves along particular segments of the mRNA. The reasons behind such segmental variability in the rates of protein synthesis, and thus polypeptide emergence from the ribosome, have been explored by theoretical and experimental approaches. Predictions of the relative rates at which particular codons are translated and their impact on the nascent chain have not arrived at unequivocal conclusions. This is probably due, at least in part, to variation in the basis for classification of codons as “fast” or “slow”, as well as variability in the number and types of genes and proteins analyzed. Recent methodological advances have allowed nucleotide-resolution studies of ribosome residency times in entire transcriptomes, which confirm the non-uniform movement of ribosomes along mRNAs and shed light on the actual determinants of rate control. Moreover, experiments have begun to emerge that systematically examine the influence of variations in ribosomal movement and the fate of the emerging polypeptide chain.

  11. Biosynthesis of human sialophorins and analysis of the polypeptide core

    International Nuclear Information System (INIS)

    Remold-O'Donnell, E.; Kenney, D.; Rosen, F.S.

    1987-01-01

    Biosynthesis was examined of sialophorin (formerly called gpL115) which is altered in the inherited immunodeficiency Wiskott-Aldrich syndrome. Sialophorin is greater than 50% carbohydrate, primarily O-linked units of sialic acid, galactose, and galactosamine. Pulse-labeling with [ 35 S]methionine and chase incubation established that sialophorin is synthesized in CEM lymphoblastoid cells as an Mr 62,000 precursor which is converted within 45 min to mature glycosylated sialophorin, a long-lived molecule. Experiments with tunicamycin and endoglycosidase H demonstrated that sialophorin contains N-linked carbohydrate (approximately two units per molecule) and is therefore an N,O-glycoprotein. Pulse-labeling of tunicamycin-treated CEM cells together with immunoprecipitation provided the means to isolate the [ 35 S]-methionine-labeled polypeptide core of sialophorin and determine its molecular weight (58,000). This datum allowed us to express the previously established composition on a per molecule basis and determine that sialophorin molecules contain approximately 520 amino acid residues and greater than or equal to 100 O-linked carbohydrate units. A recent study showed that various blood cells express sialophorin and that there are two molecular forms: lymphocyte/monocyte sialophorin and platelet/neutrophil sialophorin. Biosynthesis of the two forms was compared by using sialophorin of CEM cells and sialophorin of MOLT-4 cells (another lymphoblastoid line) as models for lymphocyte/monocyte sialophorin and platelet/neutrophil sialophorin, respectively. The time course of biosynthesis and the content of N units were found to be identical for the two sialophorin species. [ 35 S]Methionine-labeled polypeptide cores of CEM sialophorin and MOLT sialophorin were isolated and compared by electrophoresis, isoelectrofocusing, and a newly developed peptide mapping technique

  12. Electrochemical studies of the effect of H2 on UO2 dissolution

    International Nuclear Information System (INIS)

    King, F.; Shoesmith, D.W.

    2004-09-01

    This report summarises evidence for the effect of H 2 on the oxidation and dissolution of UO 2 derived from electrochemical studies. In the presence of γ-radiation or with SIMFUEL electrodes containing ε-particles, the corrosion potential (E CORR ) of UO 2 is observed to be suppressed in the presence of H 2 by up to several hundred milli volts. This effect has been observed at room temperature with 5 MPa H 2 (in the case of γ-irradiated solutions) and at 60 deg C with a H 2 partial pressure of only 0.002-0.014 MPa H 2 with the SIMFUEL electrode. The suppression of E CORR in the presence of H 2 indicates that the degree of surface oxidation and the rate of dissolution of UO 2 is lower in the presence of H 2 .The precise mechanism of the effect of H 2 is unclear at this time. The mechanism appears to involve a surface heterogeneous process, rather than a homogeneous solution process. Under some circumstances the value of E CORR approaches the equilibrium potential for the H 2 /H + couple, suggesting galvanic coupling between sites on which this electrochemical process is catalysed and the rest of the UO 2 surface. It is also possible that H* radical species, either produced radiolytically from H 2 O or by dissociation of H 2 on ε-particles or surface-active UO 2+x sites, reduce oxidised U(V)/U(VI) surface states to U(IV). The effect of H 2 on reducing the degree of surface oxidation is only partially reversible, since surfaces reduced in H 2 atmospheres (re-)oxidise more slowly and to a lesser degree than surfaces not previously exposed to H 2 . Homogeneous reactions between dissolved H 2 and either oxidants or dissolved U(VI) cannot explain the observed effects.Regardless of the precise mechanism, the suppression of the degree of surface oxidation results in lower UO 2 dissolution rates in the presence of H 2 . Application of an electro-chemical dissolution model to the observed E CORR values suggests that the fractional dissolution rate of used fuel in the

  13. High resolution spectroscopy of the Martian atmosphere - Study of seasonal variations of CO, O3, H2O, and T on the north polar cap and a search for SO2, H2O2, and H2CO

    Science.gov (United States)

    Krasnopolsky, V. A.; Chakrabarti, S.; Larson, H.; Sandel, B. R.

    1992-01-01

    An overview is presented of an observational campaign which will measure (1) the seasonal variations of the CO mixing ratio on the Martian polar cap due to accumulation and depletion of CO during the condensation and evaporation of CO2, as well as (2) the early spring ozone and water vapor of the Martian north polar cap, and (3) the presence of H2CO, H2O2, and SO2. The lines of these compounds will be measured by a combined 4-m telescope and Fourier-transform spectrometer 27097.

  14. Exposure of insect cells to ionising radiation in vivo induces persistent phosphorylation of a H2AX homologue (H2AvB).

    Science.gov (United States)

    Siddiqui, Mohammad S; Filomeni, Erika; François, Maxime; Collins, Samuel R; Cooper, Tamara; Glatz, Richard V; Taylor, Phillip W; Fenech, Michael; Leifert, Wayne R

    2013-09-01

    The response of eukaryotic cells to ionising radiation (IR)-induced double-strand DNA breaks is highly conserved and involves a DNA repair mechanism characterised by the early phosphorylation of histone protein H2AX (producing the active form γH2AX). Although the expression of an induced γH2AX variant has been detected in Drosophila melanogaster, the expression and radiation response of a γH2AX homologue has not been reported in economically important fruit flies. We use Bactrocera tryoni (Diptera: Tephritidae, Queensland fruit fly or 'Q-fly') to investigate this response with a view to developing molecular assays to detect/quantify exposure of fruit flies to IR and consequent DNA damage. Deep sequencing confirmed the presence of a H2AX homologue that we have termed H2AvB (i.e. variant Bactrocera) and has an identical sequence to a histone reported from the human disease vector Glossina morsitans. A linear dose-response of γH2AvB (0-400 Gy IR) was observed in whole Q-fly pupal lysates 24h post-IR and was detected at doses as low as 20 Gy. γH2AvB signal peaked at ~20min after IR exposure and at 24h post-IR the signal remained elevated but declined significantly by 5 days. Persistent and dose-dependent γH2AvB signal could be detected and quantified either by western blot or by laser scanning cytometry up to 17 days post-IR exposure in histone extracts or isolated nuclei from adult Q-flies (irradiated as pupae). We conclude that IR exposure in Q-fly leads to persistent γH2AvB signals (over a period of days) that can easily be detected by western blot or quantitative immunofluorescence techniques. These approaches have potential as the basis for assays for detection and quantification of prior IR exposure in pest fruit flies.

  15. Transcriptome analysis of H2O2-treated wheat seedlings reveals a H2O2-responsive fatty acid desaturase gene participating in powdery mildew resistance.

    Directory of Open Access Journals (Sweden)

    Aili Li

    Full Text Available Hydrogen peroxide (H(2O(2 plays important roles in plant biotic and abiotic stress responses. However, the effect of H(2O(2 stress on the bread wheat transcriptome is still lacking. To investigate the cellular and metabolic responses triggered by H(2O(2, we performed an mRNA tag analysis of wheat seedlings under 10 mM H(2O(2 treatment for 6 hour in one powdery mildew (PM resistant (PmA and two susceptible (Cha and Han lines. In total, 6,156, 6,875 and 3,276 transcripts were found to be differentially expressed in PmA, Han and Cha respectively. Among them, 260 genes exhibited consistent expression patterns in all three wheat lines and may represent a subset of basal H(2O(2 responsive genes that were associated with cell defense, signal transduction, photosynthesis, carbohydrate metabolism, lipid metabolism, redox homeostasis, and transport. Among genes specific to PmA, 'transport' activity was significantly enriched in Gene Ontology analysis. MapMan classification showed that, while both up- and down- regulations were observed for auxin, abscisic acid, and brassinolides signaling genes, the jasmonic acid and ethylene signaling pathway genes were all up-regulated, suggesting H(2O(2-enhanced JA/Et functions in PmA. To further study whether any of these genes were involved in wheat PM response, 19 H(2O(2-responsive putative defense related genes were assayed in wheat seedlings infected with Blumeria graminis f. sp. tritici (Bgt. Eight of these genes were found to be co-regulated by H(2O(2 and Bgt, among which a fatty acid desaturase gene TaFAD was then confirmed by virus induced gene silencing (VIGS to be required for the PM resistance. Together, our data presents the first global picture of the wheat transcriptome under H(2O(2 stress and uncovers potential links between H(2O(2 and Bgt responses, hence providing important candidate genes for the PM resistance in wheat.

  16. Intermolecular potential and rovibrational states of the H2O–D2 complex

    International Nuclear Information System (INIS)

    Avoird, Ad van der; Scribano, Yohann; Faure, Alexandre; Weida, Miles J.; Fair, Joanna R.; Nesbitt, David J.

    2012-01-01

    Graphical abstract: H 2 O–D 2 potential surface and pH 2 O–oD 2 ground state wave function, for planar geometries. Highlights: ► The interaction between H 2 O and H 2 is of great astrophysical interest. ► The rovibrational states of H 2 O–D 2 were computed on an ab initio potential surface. ► Results are compared with the rovibrational states of H 2 O–H 2 computed recently. ► We measured the high-resolution infrared spectrum of H 2 O–D 2 in the H 2 O bend region. ► Comparison with the calculations provides information on H 2 O–H 2 potential surface. - Abstract: A five-dimensional intermolecular potential for H 2 O–D 2 was obtained from the full nine-dimensional ab initio potential surface of Valiron et al. [P. Valiron, M. Wernli, A. Faure, L. Wiesenfeld, C. Rist, S. Kedžuch, J. Noga, J. Chem. Phys. 129 (2008) 134306] by averaging over the ground state vibrational wave functions of H 2 O and D 2 . On this five-dimensional potential with a well depth D e of 232.12 cm −1 we calculated the bound rovibrational levels of H 2 O–D 2 for total angular momentum J = 0–3. The method used to compute the rovibrational levels is similar to a scattering approach—it involves a basis of coupled free rotor wave functions for the hindered internal rotations and the overall rotation of the dimer—while it uses a discrete variable representation of the intermolecular distance coordinate R. The basis was adapted to the permutation symmetry associated with the para/ortho (p/o) nature of both H 2 O and D 2 , as well as to inversion symmetry. As expected, the H 2 O–D 2 dimer is more strongly bound than its H 2 O–H 2 isotopologue [cf. A. van der Avoird, D.J. Nesbitt, J. Chem. Phys. 134 (2011) 044314], with dissociation energies D 0 of 46.10, 50.59, 67.43, and 73.53 cm −1 for pH 2 O–oD 2 , oH 2 O–oD 2 , pH 2 O–pD 2 , and oH 2 O–pD 2 . A rotationally resolved infrared spectrum of H 2 O–D 2 was measured in the frequency region of the H 2 O bend

  17. Reorganization of Damaged Chromatin by the Exchange of Histone Variant H2A.Z-2

    Energy Technology Data Exchange (ETDEWEB)

    Nishibuchi, Ikuno [Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima (Japan); Department of Radiation Oncology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Department of Radiation Oncology, Hiroshima Prefectural Hospital, Hiroshima (Japan); Suzuki, Hidekazu; Kinomura, Aiko; Sun, Jiying; Liu, Ning-Ang [Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima (Japan); Horikoshi, Yasunori [Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima (Japan); Research Center for Mathematics of Chromatin Live Dynamics, Hiroshima University, Hiroshima (Japan); Shima, Hiroki [Department of Biochemistry, Graduate School of Medical Sciences, Tohoku University, Sendai (Japan); Kusakabe, Masayuki; Harata, Masahiko [Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University, Sendai (Japan); Fukagawa, Tatsuo [Department of Molecular Genetics, National Institute of Genetics and The Graduate University for Advanced Studies, Mishima (Japan); Ikura, Tsuyoshi [Laboratory of Chromatin Regulatory Network, Department of Mutagenesis, Radiation Biology Center, Kyoto University, Kyoto (Japan); Ishida, Takafumi [Department of Cardiovascular Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Nagata, Yasushi [Department of Radiation Oncology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Tashiro, Satoshi, E-mail: ktashiro@hiroshima-u.ac.jp [Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima (Japan); Research Center for Mathematics of Chromatin Live Dynamics, Hiroshima University, Hiroshima (Japan)

    2014-07-15

    Purpose: The reorganization of damaged chromatin plays an important role in the regulation of the DNA damage response. A recent study revealed the presence of 2 vertebrate H2A.Z isoforms, H2A.Z-1 and H2A.Z-2. However, the roles of the vertebrate H2A.Z isoforms are still unclear. Thus, in this study we examined the roles of the vertebrate H2A.Z isoforms in chromatin reorganization after the induction of DNA double-strand breaks (DSBs). Methods and Materials: To examine the dynamics of H2A.Z isoforms at damaged sites, we constructed GM0637 cells stably expressing each of the green fluorescent protein (GFP)-labeled H2A.Z isoforms, and performed fluorescence recovery after photobleaching (FRAP) analysis and inverted FRAP analysis in combination with microirradiation. Immunofluorescence staining using an anti-RAD51 antibody was performed to study the kinetics of RAD51 foci formation after 2-Gy irradiation of wild-type (WT), H2A.Z-1- and H2A.Z-2-deficient DT40 cells. Colony-forming assays were also performed to compare the survival rates of WT, H2A.Z-1-, and H2A.Z-2-deficient DT40 cells with control, and H2A.Z-1- and H2A.Z-2-depleted U2OS cells after irradiation. Results: FRAP analysis revealed that H2A.Z-2 was incorporated into damaged chromatin just after the induction of DSBs, whereas H2A.Z-1 remained essentially unchanged. Inverted FRAP analysis showed that H2A.Z-2 was released from damaged chromatin. These findings indicated that H2A.Z-2 was exchanged at DSB sites immediately after the induction of DSBs. RAD51 focus formation after ionizing irradiation was disturbed in H2A.Z-2-deficient DT40 cells but not in H2A.Z-1-deficient cells. The survival rate of H2A.Z-2-deficient cells after irradiation was lower than those of WT and H2A.Z-1- DT40 cells. Similar to DT40 cells, H2A.Z-2-depleted U2OS cells were also radiation-sensitive compared to control and H2A.Z-1-depleted cells. Conclusions: We found that vertebrate H2A.Z-2 is involved in the regulation of the DNA

  18. CASSCF/CI calculations of electronic states and potential energy surfaces of PtH2

    International Nuclear Information System (INIS)

    Balasubramanian, K.

    1987-01-01

    Complete active space MCSCF followed by MRSDCI (multireference singles and doubles configuration interaction) calculations are carried out on the electronic states of PtH 2 . Spin--orbit interaction is introduced using a relativistic configuration interaction scheme on PtH + whose d orbital Mulliken population is close to that of the d population of PtH 2 and thus enables calculation of spin--orbit splittings for the electronic states of PtH 2 . The bending potential energy surfaces of the 1 A 1 and 3 A 1 states are obtained. The 1 A 1 surface has a bent minimum and dissociates almost without a barrier into Pt( 1 S 0 ) and H 2 , while the 3 A 1 state has a large (--55 kcal/mol) barrier to dissociation into Pt( 3 D 3 )+H 2 . The ground state of PtH 2 is a bent 1 A 1 state (θ = 85 0 )

  19. Search Directions for Direct H2O2 Synthesis Catalysts Starting from Au-12 Nanoclusters

    DEFF Research Database (Denmark)

    Grabow, Lars; Larsen, Britt Hvolbæk; Falsig, Hanne

    2012-01-01

    We present density functional theory calculations on the direct synthesis of H2O2 from H-2 and O-2 over an Au-12 corner model of a gold nanoparticle. We first show a simple route for the direct formation of H2O2 over a gold nanocatalyst, by studying the energetics of 20 possible elementary...... that the rate of H2O2 and H2O formation can be determined from a single descriptor, namely, the binding energy of oxygen (E-O). Our model predicts the search direction starting from an Au-12 nanocluster for an optimal catalyst in terms of activity and selectivity for direct H2O2 synthesis. Taking also stability...

  20. Reorganization of Damaged Chromatin by the Exchange of Histone Variant H2A.Z-2

    International Nuclear Information System (INIS)

    Nishibuchi, Ikuno; Suzuki, Hidekazu; Kinomura, Aiko; Sun, Jiying; Liu, Ning-Ang; Horikoshi, Yasunori; Shima, Hiroki; Kusakabe, Masayuki; Harata, Masahiko; Fukagawa, Tatsuo; Ikura, Tsuyoshi; Ishida, Takafumi; Nagata, Yasushi; Tashiro, Satoshi

    2014-01-01

    Purpose: The reorganization of damaged chromatin plays an important role in the regulation of the DNA damage response. A recent study revealed the presence of 2 vertebrate H2A.Z isoforms, H2A.Z-1 and H2A.Z-2. However, the roles of the vertebrate H2A.Z isoforms are still unclear. Thus, in this study we examined the roles of the vertebrate H2A.Z isoforms in chromatin reorganization after the induction of DNA double-strand breaks (DSBs). Methods and Materials: To examine the dynamics of H2A.Z isoforms at damaged sites, we constructed GM0637 cells stably expressing each of the green fluorescent protein (GFP)-labeled H2A.Z isoforms, and performed fluorescence recovery after photobleaching (FRAP) analysis and inverted FRAP analysis in combination with microirradiation. Immunofluorescence staining using an anti-RAD51 antibody was performed to study the kinetics of RAD51 foci formation after 2-Gy irradiation of wild-type (WT), H2A.Z-1- and H2A.Z-2-deficient DT40 cells. Colony-forming assays were also performed to compare the survival rates of WT, H2A.Z-1-, and H2A.Z-2-deficient DT40 cells with control, and H2A.Z-1- and H2A.Z-2-depleted U2OS cells after irradiation. Results: FRAP analysis revealed that H2A.Z-2 was incorporated into damaged chromatin just after the induction of DSBs, whereas H2A.Z-1 remained essentially unchanged. Inverted FRAP analysis showed that H2A.Z-2 was released from damaged chromatin. These findings indicated that H2A.Z-2 was exchanged at DSB sites immediately after the induction of DSBs. RAD51 focus formation after ionizing irradiation was disturbed in H2A.Z-2-deficient DT40 cells but not in H2A.Z-1-deficient cells. The survival rate of H2A.Z-2-deficient cells after irradiation was lower than those of WT and H2A.Z-1- DT40 cells. Similar to DT40 cells, H2A.Z-2-depleted U2OS cells were also radiation-sensitive compared to control and H2A.Z-1-depleted cells. Conclusions: We found that vertebrate H2A.Z-2 is involved in the regulation of the DNA

  1. D/H isotopic fractionation effects in the H2-H2O system: An in-situ experimental study at supercritical water conditions

    Science.gov (United States)

    Foustoukos, D.; Mysen, B. O.

    2011-12-01

    Understanding the effect of temperature on the relative distribution of volatiles in supercritical aqueous solutions is important to constrain elemental and isotopic partitioning/fractionation effects in systems applicable to planetary interiors where the temperature-pressure conditions are often beyond existing experimental or theoretical datasets. For example, very little exists for the fundamental equilibria between H2, D2 and HD (H2 + D2 = 2HD), which, in turn, constrains the internal D/H isotope exchange and the evolution of HD in H2-containing systems such as H2-CH4 and H2-H2O. Theoretical calculations considering the partition functions of the molecules predict that with temperature increase, the equilibrium constant of this reaction approximates values that correspond to the stochastic distribution of species. These calculations consider pure harmonic vibrational frequencies, which, however, do not apply to the diatomic molecule of hydrogen, especially because anharmonic oscillations are anticipated to become stronger at high temperatures. Published experimental data have been limited to conditions lower than 468°C with large uncertainties at elevated temperatures. To address the lack of experimental data, a series of hydrothermal diamond anvil experiments has been conducted utilizing vibrational spectroscopy as a novel quantitative method to explore the relative distribution of H- and D-bearing volatiles in the H2-D2-D2O-H2O-Ti-TiO2 system. The fundamentals of this methodology are based on the distinct Raman frequency shift resulting from deuterium substitution in the H-H and O-H bonds. In detail, H2O-D2O solutions (1:1) were reacted with Ti metal (for 3-9hrs) at 600-800°C and pressures of 0.5-1 GPa, leading to formation of H2, D2, HD and HDO species through Ti oxidation and H-D isotope exchange reactions. Experimental results obtained in-situ and in the quenched gas phase, indicate a significant deviation from the theoretical estimate of the equilibrium

  2. Tipping Point

    Medline Plus

    Full Text Available ... en español Blog About OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by ... danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe ...

  3. KCd2[N(CN)2]5(H2O)4: an enmeshed honeycomb grid.

    Science.gov (United States)

    Schlueter, John A; Geiser, Urs; Funk, Kylee A

    2008-02-01

    The title compound, poly[potassium [diaquapenta-micro(2)-dicyanamido-dicadmium(II)] dihydrate], {K[Cd(2)(C(2)N(3))(5)(H(2)O)(2)].2H(2)O}(n), contains two-dimensional anionic sheets of {[Cd(2){N(CN)(2)}(H(2)O)(2)](-)}(n) with a modified (6,3)-net (layer group cm2m, No. 35). Two sets of equivalent sheets interpenetrate orthogonally to form a tetragonal enmeshed grid.

  4. Non-LTE H2+ as the source of missing opacity in the solar atmosphere

    Science.gov (United States)

    Swamy, K. S. K.; Stecher, T. P.

    1974-01-01

    The population of the various vibrational levels of the H2+ molecule has been calculated from the consideration of formation and destruction mechanisms. The resulting population is used in calculating the total absorption due to H2+ and is compared with the other known sources of opacity at several optical depths of the solar atmosphere. It is shown that the absorption due to H2+ can probably account for the missing ultraviolet opacity in the solar atmosphere.

  5. Transfer of π- from hydrogen to deuterium in H2O + D2O mixtures

    International Nuclear Information System (INIS)

    Stanislaus, S.; Measday, D.F.; Vetterli, D.; Weber, P.; Aniol, K.A.; Harston, M.R.; Armstrong, D.S.

    1989-07-01

    The transfer of stopping π - mesons from hydrogen to deuterium has been investigated in mixtures of H 2 O+D 2 O as a function of D 2 O concentration. The concentration dependence of the transfer probability is similar to that observed for the gas mixtures of H 2 and D 2 but slightly more transfer is found for H 2 O+D 2 O. (Author) 17 refs., 2 tabs., 4 figs

  6. Synthesis of CuO nanoflower and its application as a H2O2 sensor

    Indian Academy of Sciences (India)

    Administrator

    plays a role as additives which can connect nanosheets to nanoflowers, here. Figure 3a exhibits the CV response of H2O2 at different electrodes with a scanning ... H2O2 to stirred PBS produces a remarkable increase in the current. The response time is < 3 s, revealing the faster response of the sensor to H2O2 detection ...

  7. Comparison of genes required for H2O2 resistance in Streptococcus gordonii and Streptococcus sanguinis

    Science.gov (United States)

    Xu, Yifan; Itzek, Andreas

    2014-01-01

    Hydrogen peroxide (H2O2) is produced by several members of the genus Streptococcus mainly through the pyruvate oxidase SpxB under aerobic growth conditions. The acute toxic nature of H2O2 raises the interesting question of how streptococci cope with intrinsically produced H2O2, which subsequently accumulates in the microenvironment and threatens the closely surrounding population. Here, we investigate the H2O2 susceptibility of oral Streptococcus gordonii and Streptococcus sanguinis and elucidate potential mechanisms of how they protect themselves from the deleterious effect of H2O2. Both organisms are considered primary colonizers and occupy the same intraoral niche making them potential targets for H2O2 produced by other species. We demonstrate that S. gordonii produces relatively more H2O2 and has a greater ability for resistance to H2O2 stress. Functional studies show that, unlike in Streptococcus pneumoniae, H2O2 resistance is not dependent on a functional SpxB and confirms the important role of the ferritin-like DNA-binding protein Dps. However, the observed increased H2O2 resistance of S. gordonii over S. sanguinis is likely to be caused by an oxidative stress protection machinery present even under anaerobic conditions, while S. sanguinis requires a longer period of time for adaptation. The ability to produce more H2O2 and be more resistant to H2O2 might aid S. gordonii in the competitive oral biofilm environment, since it is lower in abundance yet manages to survive quite efficiently in the oral biofilm. PMID:25280752

  8. Absolute linestrengths in the H2O2 nu6 band

    Science.gov (United States)

    May, Randy D.

    1991-01-01

    Absolute linestrengths at 295 K have been measured for selected lines in the nu6 band of H2O2 using a tunable diode-laser spectrometer. H2O2 concentrations in a flowing gas mixture were determined by ultraviolet (uv) absorption at 254 nm using a collinear infrared (ir) and uv optical arrangement. The measured linestrengths are approx. 60 percent larger than previously reported values when absorption by hot bands in H2O2 is taken into account.

  9. Some physico-chemical characteristics of a modified histone H2b on acute radiation affection

    International Nuclear Information System (INIS)

    Khrapunov, S.N.; Mel'nik, G.G.; Blyum, Ya.B.; Tsudzevich, B.A.; Kucherenko, N.E.

    1980-01-01

    A study was made of optical characteristics of histone H2b isolated from liver nuclei 12 h following irradiation in a dose of 0.21 C/kg. It was demonstrated that under similar conditions, the control and exposed histones H2b have different steric organization which correlates with radiation-induced modifications of lateral radicals in H2b histone molecules

  10. Rapid fluctuations in the northern Baltic Sea H2S layer

    Science.gov (United States)

    Kankaanpää, Harri T.; Virtasalo, Joonas J.

    2017-12-01

    Hydrogen sulfide (H2S) is linked to water quality deterioration in the Baltic Sea, with widespread seafloor hypoxia. We examined the vertical and temporal variability of in situ [H2S], oxygen concentration ([O2]), temperature (T) and pH at weekly, hourly and minute intervals at 13 locations in the western Gulf of Finland in 2013-2014. The main target was the 60-100 m water depth range, containing 3.2-290 μM O2 and 6.3-22.6 μM H2S. Where gas was detected by acoustic surveys, the structure of the H2S layer was more complex compared to stations devoid of gas. Local minima and maxima in pH frequently occurred near the H2S upper boundary (redox transition zone). Except for the homogeneous, tranquil zone above the seafloor at some stations, substantial rapid changes in hydrographic conditions were common. Typically, a layer of marked temporal T variability was present atop or within the topmost H2S layers. The largest temporal changes over a weekly period were - 0.44 °C/- 10.8 μM H2S/- 0.12 pH units (at seafloor level), + 0.18 °C/+7.9 μM H2S between casts (1 h) and + 0.03 °C/- 2.5 μM H2S per minute (high resolution logging). Abrupt [H2S] changes were recorded at two stations with sediments containing free gas. The T and [H2S] changes were synchronous at several layers, reflecting water movement. We conclude that rapid changes occur in hydrographic conditions in the near-bottom H2S layer in the northern Baltic Sea, especially at locations where free gas is present in the underlying sediments.

  11. Algorithms to Solve Stochastic H2/H∞ Control with State-Dependent Noise

    Directory of Open Access Journals (Sweden)

    Ming Gao

    2014-01-01

    Full Text Available This paper is concerned with the algorithms which solve H2/H∞ control problems of stochastic systems with state-dependent noise. Firstly, the algorithms for the finite and infinite horizon H2/H∞ control of discrete-time stochastic systems are reviewed and studied. Secondly, two algorithms are proposed for the finite and infinite horizon H2/H∞ control of continuous-time stochastic systems, respectively. Finally, several numerical examples are presented to show the effectiveness of the algorithms.

  12. Tolerance of banana for fusarium wilt is associated with early H 2 O ...

    African Journals Online (AJOL)

    Production of O2•− , H2O2 and MDA, as well as changes in enzyme activities, and transcript levels of SOD and CAT in root extracts were monitored every 24 h over 4 days. The histochemical location of H2O2 was also detected. In the resistant iso-line, the accumulation of O2•− and H2O2, and the activation of SOD occurred ...

  13. Mechanisms of fat-induced gastric inhibitory polypeptide/glucose-dependent insulinotropic polypeptide secretion from K cells.

    Science.gov (United States)

    Yamane, Shunsuke; Harada, Norio; Inagaki, Nobuya

    2016-04-01

    Gastric inhibitory polypeptide/glucose-dependent insulinotropic polypeptide (GIP) is one of the incretins, which are gastrointestinal hormones released in response to nutrient ingestion and potentiate glucose-stimulated insulin secretion. Single fat ingestion stimulates GIP secretion from enteroendocrine K cells; chronic high-fat diet (HFD) loading enhances GIP secretion and induces obesity in mice in a GIP-dependent manner. However, the mechanisms of GIP secretion from K cells in response to fat ingestion and GIP hypersecretion in HFD-induced obesity are not well understood. We generated GIP-green fluorescent protein knock-in (GIP (gfp/+)) mice, in which K cells are labeled by enhanced GIP-green fluorescent protein. Microarray analysis of isolated K cells from GIP (gfp/+) mice showed that both fatty acid-binding protein 5 and G protein-coupled receptor 120 are highly expressed in K cells. Single oral administration of fat resulted in significant reduction of GIP secretion in both fatty acid-binding protein 5- and G protein-coupled receptor 120-deficient mice, showing that fatty acid-binding protein 5 and G protein-coupled receptor 120 are involved in acute fat-induced GIP secretion. Furthermore, the transcriptional factor, regulatory factor X6 (Rfx6), is highly expressed in K cells. In vitro experiments using the mouse enteroendocrine cell line, STC-1, showed that GIP messenger ribonucleic acid levels are upregulated by Rfx6. Expression levels of Rfx6 messenger ribonucleic acid as well as that of GIP messenger ribonucleic acid were augmented in the K cells of HFD-induced obese mice, in which GIP content in the small intestine is increased compared with that in lean mice fed a control diet. These results suggest that Rfx6 is involved in hypersecretion of GIP in HFD-induced obese conditions by increasing GIP gene expression.

  14. Domed Silica Microcylinders Coated with Oleophilic Polypeptides and Their Behavior in Lyotropic Cholesteric Liquid Crystals of the Same Polypeptide.

    Science.gov (United States)

    Rosu, Cornelia; Jacobeen, Shane; Park, Katherine; Reichmanis, Elsa; Yunker, Peter; Russo, Paul S

    2016-12-13

    Liquid crystals can organize dispersed particles into useful and exotic structures. In the case of lyotropic cholesteric polypeptide liquid crystals, polypeptide-coated particles are appealing because the surface chemistry matches that of the polymeric mesogen, which permits a tighter focus on factors such as extended particle shape. The colloidal particles developed here consist of a magnetic and fluorescent cylindrically symmetric silica core with one rounded, almost hemispherical end. Functionalized with helical poly(γ-stearyl-l-glutamate) (PSLG), the particles were dispersed at different concentrations in cholesteric liquid crystals (ChLC) of the same polymer in tetrahydrofuran (THF). Defects introduced by the particles to the director field of the bulk PSLG/THF host led to a variety of phases. In fresh mixtures, the cholesteric mesophase of the PSLG matrix was distorted, as reflected in the absence of the characteristic fingerprint pattern. Over time, the fingerprint pattern returned, more quickly when the concentration of the PSLG-coated particles was low. At low particle concentration the particles were "guided" by the PSLG liquid crystal to organize into patterns similar to that of the re-formed bulk chiral nematic phase. When their concentration increased, the well-dispersed PSLG-coated particles seemed to map onto the distortions in the bulk host's local director field. The particles located near the glass vial-ChLC interfaces were stacked lengthwise into architectures with apparent two-dimensional hexagonal symmetry. The size of these "crystalline" structures increased with particle concentration. They displayed remarkable stability toward an external magnetic field; hydrophobic interactions between the PSLG polymers in the shell and those in the bulk LC matrix may be responsible. The results show that bio-inspired LCs can assemble suitable colloidal particles into soft crystalline structures.

  15. CO2/H2 separation using a highly permeable polyurethane membrane: Molecular dynamics simulation

    Science.gov (United States)

    Azizi, Morteza; Mousavi, Seyyed Abbas

    2015-11-01

    In this study, Molecular Dynamics (MD) and Grand Canonical Monte Carlo (GCMC) simulations were conducted to investigate the diffusivity, solubility, and permeability of CO2, CO, H2, and H2O in a polyurethane membrane at three different temperatures. The characterization of the simulated structures was carried out using XRD, FFV, Tg and density calculation, and cavity size distribution. The obtained results were within the expectations reported data in the literature based on the experimental approach, indicating the authenticity of approached in this work. The results showed that the highest diffusivity and permeability coefficients were observed for H2; while the highest values of solubility coefficient were found for H2O and CO2 gases. The increase of operating temperature from 298 K to 318 K has a positive effect on the permeation of all gases and a corresponding negative effect on the selectivity of the gas pair CO2/H2. Also, the results vividly showed that CO2 and H2O gases have a profound affinity with hard phase of polyurethane, while H2 and CO were conversely adsorbed by soft one. Moreover, the enhancement of permeability and permselectivity of CO2/H2 pair confirmed using Robeson Upper-Bond graph showed its good capacity for CO2/H2 separation application.

  16. Impact of a future H2 transportation on atmospheric pollution in Europe

    Science.gov (United States)

    Popa, M. E.; Segers, A. J.; Denier van der Gon, H. A. C.; Krol, M. C.; Visschedijk, A. J. H.; Schaap, M.; Röckmann, T.

    2015-07-01

    Hydrogen (H2) is being explored as a fuel for passenger vehicles; it can be used in fuel cells to power electric motors or burned in internal combustion engines. In order to evaluate the potential influence of a future H2-based road transportation on the regional air quality in Europe, we implemented H2 in the atmospheric transport and chemistry model LOTOS-EUROS. We simulated the present and future (2020) air quality, using emission scenarios with different proportions of H2 vehicles and different H2 leakage rates. The reference future scenario does not include H2 vehicles, and assumes that all present and planned European regulations for emissions are fully implemented. We find that, in general, the air quality in 2020 is significantly improved compared to the current situation in all scenarios, with and without H2 cars. In the future scenario without H2 cars, the pollution is reduced due to the strict European regulations: annually averaged CO, NOx and PM2.5 over the model domain decrease by 15%, 30% and 20% respectively. The additional improvement brought by replacing 50% or 100% of traditionally-fueled vehicles by H2 vehicles is smaller in absolute terms. If 50% of vehicles are using H2, the CO, NOx and PM2.5 decrease by 1%, 10% and 1% respectively, compared to the future scenario without H2 cars. When all vehicles run on H2, then additional decreases in CO, NOx and PM2.5 are 5%, 40%, and 5% relative to the no-H2 cars future scenario. Our study shows that H2 vehicles may be an effective pathway to fulfill the strict future EU air quality regulations. O3 has a more complicated behavior - its annual average decreases in background areas, but increases in the high-NOx area in western Europe, with the decrease in NOx. A more detailed analysis shows that the population exposure to high O3 levels decreases nevertheless. In all future scenarios, traffic emissions account for only a small proportion of the total anthropogenic emissions, thus it becomes more important

  17. Stress management skills in the subsurface: H2 stress on thermophilic heterotrophs and methanogens

    Science.gov (United States)

    Topcuoglu, B. D.; Holden, J. F.

    2017-12-01

    Marine hyperthermophilic heterotrophs and methanogens belonging to the Thermococcales and Methanococcales are often found in subsurface environments such as coal and shale beds, marine sediments, and oil reservoirs where they encounter H2 stress conditions. It is important to study the H2 stress survival strategies of these organisms and their cooperation with one another for survival to better understand their biogeochemical impact in hot subsurface environments. In this study, we have shown that H2 inhibition changed the growth kinetics and the transcriptome of Thermococcus paralvinellae. We observed a significant decrease in batch phase growth rates and cell concentrations with high H2 background. Produced metabolite production measurements, RNA-seq analyses of differentially expressed genes and in silico experiments we performed with the T. paralvinellae metabolic model showed that T. paralvinellae produces formate by a formate hydrogenlyase to survive H2 inhibition. We have also shown that H2 limitation caused a significant decrease in batch phase growth rates and methane production rates of the methanogen, Methanocaldococcus jannaschii. H2 stress of both organisms can be ameliorated by syntrophic growth. H2 syntrophy was demonstrated in microcosm incubations for a natural assemblage of Thermococcus and hyperthermophilic methanogens present in hydrothermal fluid samples. This project aims to describe how a hyperthermophilic heterotroph and a hyperthermophilic methanogen eliminate H2 stress and explore cooperation among thermophiles in the hot subsurface.

  18. Fourier-Transform Microwave and Millimeterwave Spectroscopy of the H2-HCN Molecular Complex

    Science.gov (United States)

    Tanaka, Keiichi; Harada, Kensuke; Sumiyoshi, Yoshihiro; Nakajima, Masakazu; Endo, Yasuki

    2015-06-01

    Fourier-Transform microwave (FTMW) spectroscopy has been applied to observe the J = 1 - 0 rotational transitions of the H2-HCN/DCN complexes containing both the para-H2 (IH2=0) and ortho-H2 (IH2=1) molecule Rotational spectra of H2-HCN/DCN up to J = 5 - 4 were also observed in the millimeter-wave (MMW) region below 180 GHz. Observed FTMW lines for H2-HCN/DCN split into hyperfine components due to the nuclear quadrupole interaction of N and D nuclei. For the ortho-H2 species, the hyperfine splitting due to the magnetic interaction between the hydrogen nuclear spin of ortho-H2 part (jH2=1, IH2=1) was also observed, but not for the para-H2 species (jH2=0, IH2=0). From the observed nuclear spin-spin coupling constants of ortho-H2 species, d = 21.90(47) and 24.66(68) kHz for HCN and DCN complexes, respectively, the average values of = 0.380(8) and 0.439(10) were derived indicating the nearly free rotation of H2 in the complex with jH2= 1 and kH2= 0. The nuclear quadrupole interaction constants due to N and D nuclei show that the HCN/DCN part executes a floppy motion with a large mean square amplitude of about 29/25 and 33/30 degree in the para and ortho species, respectively. From the observed rotational constants, the center-of-mass distances of H2 and HCN/DCN were derived to be 3.9617(5)/4.00356 (43) Å for the ortho species and 4.1589(13)/4.1596 (36) Å for the para species. The isotope effect on rotational constants confirmed the totally different configurations in the ortho and para species: H2 is attached to the H/D end of HCN/DCN for the para species, while to the N end for the ortho species, as suggested by IR spectroscopy and theoretical study. M. Ishiguro et al., Chem. Phys. Lett. 554, 33 (2012). M. Ishiguro et al., J. Chem. Phys. 115, 5155 (2001).

  19. Light-Activated COS/H2S Donation from Photocaged Thiocarbamates.

    Science.gov (United States)

    Zhao, Yu; Bolton, Sarah G; Pluth, Michael D

    2017-05-05

    Hydrogen sulfide (H 2 S) is an important biomolecule, and responsive chemical tools for its delivery are needed. Here, we utilize the photocleavable o-nitrobenzyl group to unmask caged thiocarbamates and to access photoactivated H 2 S releasing molecules. These donors function by the initial release of carbonyl sulfide (COS), which is quickly hydrolyzed to H 2 S by carbonic anhydrase (CA). Our investigations demonstrate that o-nitrobenzyl-caged thiocarbamates can serve as a donor platform for the bio-orthogonal stimulated release of COS/H 2 S.

  20. Formate-dependent H2 production by the mesophilic methanogen Methanococcus maripaludis.

    Science.gov (United States)

    Lupa, Boguslaw; Hendrickson, Erik L; Leigh, John A; Whitman, William B

    2008-11-01

    Methanococcus maripaludis, an H(2)- and formate-utilizing methanogen, produced H(2) at high rates from formate. The rates and kinetics of H(2) production depended upon the growth conditions, and H(2) availability during growth was a major factor. Specific activities of resting cells grown with formate or H(2) were 0.4 to 1.4 U mg(-1) (dry weight). H(2) production in formate-grown cells followed Michaelis-Menten kinetics, and the concentration of formate required for half-maximal activity (K(f)) was 3.6 mM. In contrast, in H(2)-grown cells this process followed sigmoidal kinetics, and the K(f) was 9 mM. A key enzyme for formate-dependent H(2) production was formate dehydrogenase, Fdh. H(2) production and growth were severely reduced in a mutant containing a deletion of the gene encoding the Fdh1 isozyme, indicating that it was the primary Fdh. In contrast, a mutant containing a deletion of the gene encoding the Fdh2 isozyme possessed near-wild-type activities, indicating that this isozyme did not play a major role. H(2) production by a mutant containing a deletion of the coenzyme F(420)-reducing hydrogenase Fru was also severely reduced, suggesting that the major pathway of H(2) production comprised Fdh1 and Fru. Because a Deltafru-Deltafrc mutant retained 10% of the wild-type activity, an additional pathway is present. Mutants possessing deletions of the gene encoding the F(420)-dependent methylene-H(4)MTP dehydrogenase (Mtd) or the H(2)-forming methylene-H(4)MTP dehydrogenase (Hmd) also possessed reduced activity, which suggested that this second pathway was comprised of Fdh1-Mtd-Hmd. In contrast to H(2) production, the cellular rates of methanogenesis were unaffected in these mutants, which suggested that the observed H(2) production was not a direct intermediate of methanogenesis. In conclusion, high rates of formate-dependent H(2) production demonstrated the potential of M. maripaludis for the microbial production of H(2) from formate.