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Sample records for picornaviral 3c cysteine

  1. Roles of the Picornaviral 3C Proteinase in the Viral Life Cycle and Host Cells

    Directory of Open Access Journals (Sweden)

    Di Sun

    2016-03-01

    Full Text Available The Picornaviridae family comprises a large group of non-enveloped viruses that have a major impact on human and veterinary health. The viral genome contains one open reading frame encoding a single polyprotein that can be processed by viral proteinases. The crucial 3C proteinases (3Cpros of picornaviruses share similar spatial structures and it is becoming apparent that 3Cpro plays a significant role in the viral life cycle and virus host interaction. Importantly, the proteinase and RNA-binding activity of 3Cpro are involved in viral polyprotein processing and the initiation of viral RNA synthesis. In addition, 3Cpro can induce the cleavage of certain cellular factors required for transcription, translation and nucleocytoplasmic trafficking to modulate cell physiology for viral replication. Due to interactions between 3Cpro and these essential factors, 3Cpro is also involved in viral pathogenesis to support efficient infection. Furthermore, based on the structural conservation, the development of irreversible inhibitors and discovery of non-covalent inhibitors for 3Cpro are ongoing and a better understanding of the roles played by 3Cpro may provide insights into the development of potential antiviral treatments. In this review, the current knowledge regarding the structural features, multiple functions in the viral life cycle, pathogen host interaction, and development of antiviral compounds for 3Cpro is summarized.

  2. Analysis of S-nitrosothiols via Copper Cysteine (2C) and Copper Cysteine - Carbon Monoxide (3C) Methods

    Science.gov (United States)

    Rogers, Stephen C.; Gibbons, Lindsey B.; Griffin, Sherraine; Doctor, Allan

    2012-01-01

    This chapter summarizes the principles of RSNO measurement in the gas phase, utilizing ozone-based chemiluminescence and the copper cysteine (2C) ± carbon monoxide (3C) reagent. Although an indirect method for quantifying RSNOs, this assay represents one of the most robust methodologies available. It exploits the NO• detection sensitivity of ozone based chemiluminscence, which is within the range required to detect physiological concentrations of RSNO metabolites. Additionally, the specificity of the copper cysteine (2C and 3C) reagent for RSNOs negates the need for sample pretreatment, thereby minimizing the likelihood of sample contamination (false positive results), NO species inter-conversion, or the loss of certain highly labile RSNO species. Herein, we outline the principles of this methodology, summarizing key issues, potential pitfalls and corresponding solutions. PMID:23116707

  3. Identification of Cleavage Sites Recognized by the 3C-Like Cysteine Protease within the Two Polyproteins of Strawberry Mottle Virus

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    Hélène Sanfaçon

    2017-04-01

    Full Text Available Strawberry mottle virus (SMoV, family Secoviridae, order Picornavirales is one of several viruses found in association with strawberry decline disease in Eastern Canada. The SMoV genome consists of two positive-sense single-stranded RNAs, each encoding one large polyprotein. The RNA1 polyprotein (P1 includes the domains for a putative helicase, a VPg, a 3C-like cysteine protease and an RNA-dependent RNA polymerase at its C-terminus, and one or two protein domains at its N-terminus. The RNA2 polyprotein (P2 is predicted to contain the domains for a movement protein (MP and one or several coat proteins at its N-terminus, and one or more additional domains for proteins of unknown function at its C-terminus. The RNA1-encoded 3C-like protease is presumed to cleave the two polyproteins in cis (P1 and in trans (P2. Using in vitro processing assays, we systematically scanned the two polyproteins for cleavage sites recognized by this protease. We identified five cis-cleavage sites in P1, with cleavage between the putative helicase and VPg domains being the most efficient. The presence of six protein domains in the SMoV P1, including two upstream of the putative helicase domain, is a feature shared with nepoviruses but not with comoviruses. Results from trans-cleavage assays indicate that the RNA1-encoded 3C-like protease recognized a single cleavage site, which was between the predicted MP and coat protein domains in the P2 polyprotein. The cleavage site consensus sequence for the SMoV 3C-like protease is AxE (E or Q/(G or S.

  4. Structures and Corresponding Functions of Five Types of Picornaviral 2A Proteins

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    Xiaoyao Yang

    2017-07-01

    Full Text Available Among the few non-structural proteins encoded by the picornaviral genome, the 2A protein is particularly special, irrespective of structure or function. During the evolution of the Picornaviridae family, the 2A protein has been highly non-conserved. We believe that the 2A protein in this family can be classified into at least five distinct types according to previous studies. These five types are (A chymotrypsin-like 2A, (B Parechovirus-like 2A, (C hepatitis-A-virus-like 2A, (D Aphthovirus-like 2A, and (E 2A sequence of the genus Cardiovirus. We carried out a phylogenetic analysis and found that there was almost no homology between each type. Subsequently, we aligned the sequences within each type and found that the functional motifs in each type are highly conserved. These different motifs perform different functions. Therefore, in this review, we introduce the structures and functions of these five types of 2As separately. Based on the structures and functions, we provide suggestions to combat picornaviruses. The complexity and diversity of the 2A protein has caused great difficulties in functional and antiviral research. In this review, researchers can find useful information on the 2A protein and thus conduct improved antiviral research.

  5. Interstellar clouds toward 3C 154 and 3C 353

    International Nuclear Information System (INIS)

    Federman, S.R.; Evans, N.J. II; Willson, R.F.; Falgarone, E.; Combes, F.; Texas Univ., Austin; Tufts Univ., Medford, MA; Meudon, Observatoire, France)

    1987-01-01

    Molecular observations of the interstellar clouds toward the radio sources 3C 154 and 3C 353 were obtained in order to elucidate the physical conditions within the clouds. Maps of (C-12)O emission in the J = 1-0 and J = 2-1 lines were compared with observations of the (C-13)O, CH, and OH molecules. The peak emission in the (C-12)O transitions does not occur in the direction of the continuum sources, and thus, an incomplete picture arises when only one line of sight in the two clouds is analyzed. The cloud toward 3C 154 appears to have a low extinction, but a relatively high CO abundance, suggesting that it is similar to high-latitude clouds and CO-rich diffuse clouds. The cloud toward 3C 353 is considerably denser than that toward 3C 154 and may be more like a dark cloud. 32 references

  6. Cysteine proteinases and cystatins

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    Adeliana S. Oliveira

    2003-01-01

    Full Text Available This review describeds the definition, localization, functions and examples of cysteine proteinases and their protein inhibitors in vertebrate, non-vertebrate animals and plants. These inhibitors are related with defense mechanisms of plant against pests. It also describes the factors involved in the specific cysteine proteinase-cystatin interaction and high degree of affinity and large specificity in this interaction which are not only represented by the compatibility between amino acid residues of the active site involved in catalysis, but also of all amino acid residues that participante in the enzyme-inhibitor interaction.Nesta revisão foram descritas definições, localizações, funções e exemplos de proteinases cisteínicas e suas proteinas inibidoras em animais vertebrados e invertebrados e plantas. Tratamos principalmente com aqueles inibidores que são relatados com o mecanismo de defesa da planta contra pestes. Em adição, comentamos sobre recentes trabalhos que contribuíram para uma melhor compreenção dos fatores envolvidos na interação específica proteinase cisteínica-cistatina. Por outro lado, chamamos atenção para o alto grau de afinidade e grande especificidade na interação que não são apenas representadas pela compatibilidade entre os residuos de aminoácidos do sítio ativo envolvidos na catalise, mas também de todos os resíduos de aminoácidos que participam da interação enzima-inibidor.

  7. Assay of cysteine dioxygenase activity

    International Nuclear Information System (INIS)

    Bagley, P.J.; Stipanuk, M.H.

    1990-01-01

    It has been proposed that rat liver contains two cysteine dioxygenase enzymes which convert cysteine to cysteinesulfinic acid, one which is stimulated by NAD + and has a pH optimum of 6.8 and one which is not stimulated by NAD + and has a pH optimum of 9.0. This led the authors to reinvestigate assay conditions for measuring cysteine dioxygenase activity in rat liver homogenate. An HPLC method, using an anion exchange column (Dionex Amino-Pac trademark PA1 (4x250 mm)) was used to separate the [ 35 S]cysteinesulfinic acid produced from [ 35 S]cysteine in the incubation mixture. They demonstrated that inclusion of hydroxylamine prevented further metabolism of cysteinesulfinic acid. which occurred rapidly in the absence of hydroxylamine

  8. Cysteine Protease Zymography: Brief Review.

    Science.gov (United States)

    Wilkesman, Jeff

    2017-01-01

    Cysteine proteases play multiple roles in basically all aspects of physiology and development. In plants, they are involved in growth and development and in accumulation and mobilization of storage proteins. Furthermore, they are engaged in signalling pathways and in the response to biotic and abiotic stresses. In animals and also in humans, they are responsible for senescence and apoptosis, prohormone processing, and ECM remodelling. When analyzed by zymography, the enzyme must be renaturated after SDS-PAGE. SDS must be washed out and substituted by Triton X-100. Gels are then further incubated under ideal conditions for activity detection. Cysteine proteases require an acidic pH (5.0-6.0) and a reducing agent, usually DTT. When screening biological samples, there is generally no previous clue on what peptidase class will be present, neither optimal proteolysis conditions are known. Hence, it is necessary to assess several parameters, such as incubation time, pH, temperature, influence of ions or reducing agents, and finally evaluate the inhibition profile. For detection of cysteine peptidase activity, the use of specific inhibitors, such as E-64, can be used to prevent the development of cysteine peptidase activity bands and positively confirm its presence. Here four different protocols to assess cysteine protease activity from different sources are presented.

  9. 35S cystein chlorhydrate preparation

    International Nuclear Information System (INIS)

    Emiliozzi, R.; Pichat, P.; Herbert, M.

    1960-01-01

    35 S cystein chlorhydrate has been prepared with a quantitative yield by electrolytic reduction of 35 S cystin in hydrochloric medium on a vibrating mercury cathode. Reprint of a paper published in Bulletin de la Societe chimique de France, no. 2653, 4. quarter 1959, p. 1544-1545 [fr

  10. The spectrum of 3C 58

    International Nuclear Information System (INIS)

    Kirshner, R.P.; Fesen, R.A.

    1978-01-01

    Digital spectra of three faint knots in the SNR 3C 58 have been obtained in the wavelength range lambdalambda4700--7300 with the intensified Reticon spectrometer at the 1.3 m telescope of McGraw-Hill Observatory. Emission lines of [S II], [N II], Hα, and [O III] were detected with radial velocities less than 100 km s -1 . Although 3C 58 resembles the Crab Nebula in its radio properties and is thought to be the remnant of the supernova observed in A.D. 1181, the relative line intensities and radial velocities reported here more nearly resemble those of the Cygnus Loop and Kepler's SNR

  11. The jets in 3C 449 revisited

    International Nuclear Information System (INIS)

    Cornwell, T.J.; Perley, R.A.

    1982-01-01

    Bridle (this volume) has summarized the overall characteristics of the jets found in numerous low-luminosity and some high-luminosity radio sources. Previous observations made with the partially completed VLA at wavelengths of 6 and 2O cm indicated that 3C449 was an archetypal radio source obeying all the ''rules'' summarized by Bridle. New observations with the VLA of the polarization structure at 6 and 2O cm have destroyed this simple picture and identify 3C449 as a ''rogue'' jet source. (Auth.)

  12. Analyzing polarization swings in 3C 279

    Directory of Open Access Journals (Sweden)

    Kiehlmann S.

    2013-12-01

    Full Text Available Quasar 3C 279 is known to exhibit episodes of optical polarization angle rotation. We present new, well-sampled optical polarization data for 3C 279 and introduce a method to distinguish between random and deterministic electric vector position angle (EVPA variations. We observe EVPA rotations in both directions with different amplitudes and find that the EVPA variation shows characteristics of both random and deterministic cases. Our analysis indicates that the EVPA variation is likely dominated by a random process in the low brightness state of the jet and by a deterministic process in the flaring state.

  13. 3C in Maize and Arabidopsis

    NARCIS (Netherlands)

    Weber, B.; Jamge, S.; Stam, M.; Bemer, M.; Baroux, C.

    2018-01-01

    With Chromosome Conformation Capture (3C), the relative interaction frequency of one chromosomal fragment with another can be determined. The technique is especially suited for unraveling the 3D organization of specific loci when focusing on aspects such as enhancer-promoter interactions or other

  14. The kinetically dominated quasar 3C 418

    Science.gov (United States)

    Punsly, Brian; Kharb, Preeti

    2017-06-01

    The existence of quasars that are kinetically dominated, where the jet kinetic luminosity, Q, is larger than the total (infrared to X-ray) thermal luminosity of the accretion flow, Lbol, provides a strong constraint on the fundamental physics of relativistic jet formation. Since quasars have high values of Lbol by definition, only ˜10 kinetically dominated quasars (with \\overline{Q}/L_{bol}>1) have been found, where \\overline{Q} is the long-term time-averaged jet power. We use low-frequency (151 MHz-1.66 GHz) observations of the quasar 3C 418 to determine \\overline{Q}≈ 5.5 ± 1.3 × 10^{46} {erg s^{-1}}. Analysis of the rest-frame ultraviolet spectrum indicates that this equates to 0.57 ± 0.28 times the Eddington luminosity of the central supermassive black hole and \\overline{Q}/L_{bol} ≈ 4.8 ± 3.1, making 3C 418 one of the most kinetically dominated quasars found to date. It is shown that this maximal \\overline{Q}/L_{bol} is consistent with models of magnetically arrested accretion of jet production in which the jet production reproduces the observed trend of a decrement in the extreme ultraviolet continuum as the jet power increases. This maximal condition corresponds to an almost complete saturation of the inner accretion flow with vertical large-scale magnetic flux (maximum saturation).

  15. Protein cysteine oxidation in redox signaling

    DEFF Research Database (Denmark)

    Forman, Henry Jay; Davies, Michael J; Krämer, Anna C

    2017-01-01

    Oxidation of critical signaling protein cysteines regulated by H2O2 has been considered to involve sulfenic acid (RSOH) formation. RSOH may subsequently form either a sulfenyl amide (RSNHR') with a neighboring amide, or a mixed disulfide (RSSR') with another protein cysteine or glutathione. Previ...

  16. Yeast genes involved in regulating cysteine uptake affect production of hydrogen sulfide from cysteine during fermentation.

    Science.gov (United States)

    Huang, Chien-Wei; Walker, Michelle E; Fedrizzi, Bruno; Gardner, Richard C; Jiranek, Vladimir

    2017-08-01

    An early burst of hydrogen sulfide (H2S) produced by Saccharomyces cerevisiae during fermentation could increase varietal thiols and therefore enhance desirable tropical aromas in varieties such as Sauvignon Blanc. Here we attempted to identify genes affecting H2S formation from cysteine by screening yeast deletion libraries via a colony colour assay on media resembling grape juice. Both Δlst4 and Δlst7 formed lighter coloured colonies and produced significantly less H2S than the wild type on high concentrations of cysteine, likely because they are unable to take up cysteine efficiently. We then examined the nine known cysteine permeases and found that deletion of AGP1, GNP1 and MUP1 led to reduced production of H2S from cysteine. We further showed that deleting genes involved in the SPS-sensing pathway such as STP1 and DAL81 also reduced H2S from cysteine. Together, this study indirectly confirms that Agp1p, Gnp1p and Mup1p are the major cysteine permeases and that they are regulated by the SPS-sensing and target of rapamycin pathways under the grape juice-like, cysteine-supplemented, fermentation conditions. The findings highlight that cysteine transportation could be a limiting factor for yeast to generate H2S from cysteine, and therefore selecting wine yeasts without defects in cysteine uptake could maximise thiol production potential. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. The jets of 3C120

    International Nuclear Information System (INIS)

    Axon, D.J.; Pedlar, A.; Unger, S.W.; Meurs, E.J.A.; Ward, M.J.

    1989-01-01

    Core-dominated radio sources associated with quasars are a manifestation of the most extreme form of activity in galactic nuclei. In general, the morphology of their inner radio structure is in the form of a jet detected on only one side of the core; the larger-scale radio emission is relatively symmetric. Superluminal motion in some sources has led to the suggestion that the ejection of radio-emitting material is relativistic and intrinsically two-sided. The apparent one-sidedness of the jets is then explained by relativistic aberration. This persuasive interpretation has not escaped criticism: both physical and statistical arguments have been advanced in favour of one-sided ejection. However, our new optical observations of 3C120, which reveal the details of the interaction between the radio jet and the quiescent gas in the galaxy, offer significant kinematic evidence in favour of the relativistic-beaming hypothesis. (author)

  18. Evidence for cysteine sulfinate as a neurotransmitter

    International Nuclear Information System (INIS)

    Recasens, M.; Varga, V.; Nanopoulos, D.; Saadoun, F.; Vincendon, G.; Benavides, J.

    1982-01-01

    The Na + -independent binding of L-[ 3 H]cysteine sulfinate and L-[ 3 H]cysteine sulfinate uptake were investigated in rat brain membranes and vesicles. Specific binding of L-[ 3 H]cysteine sulfinate was saturable and occurred by a single high affinity process with a Ksub(b) of 100 nM +- 9 and a capacity (Bsub(max)) of 2.4 +- 0.22 pmol/mg protein. The regional distribution of the binding of L-[ 3 H]cysteine sulfinate in the brain was found to be heterogeneous. The rate of L-[ 3 H]cysteine sulfinate uptake shows a biphasic dependence on the concentration of L-cysteine sulfinate, corresponding to a high affinity (27.2 μM) and a low affinity (398 μM) transport system. The maximum L-[ 3 H]cysteine sulfinate uptake is reached at 2min and the uptake increases as a function of the sodium concentration. Chloride and potassium ions stimulate the uptake. (Auth.)

  19. THE SUZAKU VIEW OF 3C 382

    International Nuclear Information System (INIS)

    Sambruna, R. M.; Gliozzi, M.; Tombesi, F.; Reeves, J. N.; Braito, V.; Ballo, L.; Reynolds, C. S.

    2011-01-01

    We present a long (116 ks) Suzaku observation of the broad-line radio galaxy (BLRG) 3C 382 acquired in 2007 April. A Swift BAT spectrum in 15-200 keV from the 58 month survey is also analyzed, together with an archival XMM-Newton EPIC exposure of 20 ks obtained one year after Suzaku. Our main result is the finding with Suzaku of a broad Fe K line with a relativistic profile consistent with emission from an accretion disk at tens of gravitational radii from the central black hole. The XIS data indicate emission from highly ionized iron and allow us to set tight, albeit model-dependent, constraints on the inner and outer radii of the disk reflecting region, r in ≅ 10 r g and r out ≅ 20 r g , respectively, and on the disk inclination, i ≅ 30 0 . Two ionized reflection components are possibly observed, with similar contributions of ∼10% to the total continuum-a highly ionized one, with logξ ≅ 3 erg s -1 cm, which successfully models the relativistic line, and a mildly ionized one, with logξ ≅ 1.5 erg s -1 cm, which models the narrow Fe Kα and high energy hump. When both these components are included, there is no further requirement for an additional blackbody soft excess below 2 keV. The Suzaku data confirm the presence of a warm absorber previously known from grating studies. After accounting for all the spectral features, the intrinsic photon index of the X-ray continuum is Γ x ≅ 1.8 with a cutoff energy at ∼200 keV, consistent with Comptonization models and excluding jet-related emission up to these energies. Comparison of the X-ray properties of 3C 382 and other BLRGs to Seyferts recently observed with Suzaku and BAT confirms the idea that the distinction between radio-loud and radio-quiet active galactic nucleus at X-rays is blurred. The two classes form a continuum distribution in terms of X-ray photon index, reflection strength, and Fe K line width (related to the disk emission radius), with BLRGs clustered at one end of the distribution

  20. Multiwavelength Variability Analysis of 3C 279

    Energy Technology Data Exchange (ETDEWEB)

    Patiño-Álvarez, Víctor M. [Max-Planck-Institut für Radioastronomie, Bonn (Germany); Fernandes, Sunil [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX (United States); Chavushyan, Vahram [Instituto Nacional de Astrofísica Óptica y Electrónica, Puebla (Mexico); López-Rodríguez, Erique [SOFIA Science Center, NASA Ames Center, Mountain View, CA (United States); León-Tavares, Jonathan [Centre for Remote Sensing and Earth Observation Processes (TAP), Flemish Institute for Technological Research (VITO), Mol (Belgium); Schlegel, Eric M. [Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX (United States); Carrasco, Luis; Valdés, José R.; Carramiñana, Alberto, E-mail: patinoavm@mpifr-bonn.mpg.de [Instituto Nacional de Astrofísica Óptica y Electrónica, Puebla (Mexico)

    2017-11-23

    We present a multifrequency analysis of the variability in the flat-spectrum radio quasar 3C 279 from 2008 to 2014. Our multiwavelength datasets range from 1 mm to gamma-rays, with additional optical polarimetry. Cross-correlation analysis shows a significant correlation between the UV continuum emission, the optical and NIR bands, at a delay consistent with zero, implying co-spatial emission regions. We also find a correlation between the UV continuum and the 1 mm data, which implies that the dominant process in producing the UV continuum is synchrotron emission. Based on the behavior of the gamma-ray light curve with respect to other bands, we identified three different activity periods. During period A we find a significant correlation at zero delay between the UV continuum and the gamma-rays, implying co-spatial emission regions which points toward synchrotron self-Compton as dominant gamma-ray emission mechanism. During period C we find a delay between the UV continuum and the gamma-rays, as well as a correlation at zero delay between X-rays and gamma-rays, both results implying that external inverse Compton is the dominant gamma-ray emission mechanism. During period B there are multiple flares in the bands from 1 mm to UV, however, none of these show a counterpart in the gamma-rays band. We propose that this is caused by an increase in the gamma-ray opacity due to electron-positron pair production.

  1. Sim3C: simulation of Hi-C and Meta3C proximity ligation sequencing technologies.

    Science.gov (United States)

    DeMaere, Matthew Z; Darling, Aaron E

    2018-02-01

    Chromosome conformation capture (3C) and Hi-C DNA sequencing methods have rapidly advanced our understanding of the spatial organization of genomes and metagenomes. Many variants of these protocols have been developed, each with their own strengths. Currently there is no systematic means for simulating sequence data from this family of sequencing protocols, potentially hindering the advancement of algorithms to exploit this new datatype. We describe a computational simulator that, given simple parameters and reference genome sequences, will simulate Hi-C sequencing on those sequences. The simulator models the basic spatial structure in genomes that is commonly observed in Hi-C and 3C datasets, including the distance-decay relationship in proximity ligation, differences in the frequency of interaction within and across chromosomes, and the structure imposed by cells. A means to model the 3D structure of randomly generated topologically associating domains is provided. The simulator considers several sources of error common to 3C and Hi-C library preparation and sequencing methods, including spurious proximity ligation events and sequencing error. We have introduced the first comprehensive simulator for 3C and Hi-C sequencing protocols. We expect the simulator to have use in testing of Hi-C data analysis algorithms, as well as more general value for experimental design, where questions such as the required depth of sequencing, enzyme choice, and other decisions can be made in advance in order to ensure adequate statistical power with respect to experimental hypothesis testing.

  2. Multiwavelength Variability Analysis of 3C 279

    Directory of Open Access Journals (Sweden)

    Víctor M. Patiño-Álvarez

    2017-11-01

    Full Text Available We present a multifrequency analysis of the variability in the flat-spectrum radio quasar 3C 279 from 2008 to 2014. Our multiwavelength datasets range from 1 mm to gamma-rays, with additional optical polarimetry. Cross-correlation analysis shows a significant correlation between the UV continuum emission, the optical and NIR bands, at a delay consistent with zero, implying co-spatial emission regions. We also find a correlation between the UV continuum and the 1 mm data, which implies that the dominant process in producing the UV continuum is synchrotron emission. Based on the behavior of the gamma-ray light curve with respect to other bands, we identified three different activity periods. During period A we find a significant correlation at zero delay between the UV continuum and the gamma-rays, implying co-spatial emission regions which points toward synchrotron self-Compton as dominant gamma-ray emission mechanism. During period C we find a delay between the UV continuum and the gamma-rays, as well as a correlation at zero delay between X-rays and gamma-rays, both results implying that external inverse Compton is the dominant gamma-ray emission mechanism. During period B there are multiple flares in the bands from 1 mm to UV, however, none of these show a counterpart in the gamma-rays band. We propose that this is caused by an increase in the gamma-ray opacity due to electron-positron pair production.

  3. The Resolved Outflow from 3C 48

    Science.gov (United States)

    Shih, Hsin-Yi; Stockton, Alan

    2014-10-01

    We investigate the properties of the high-velocity outflow driven by the young radio jet of 3C 48, a compact-steep-spectrum source. We use the Space Telescope Imaging Spectrograph on board the Hubble Space Telecope to obtain (1) low-resolution UV and optical spectra and (2) multi-slit medium-resolution spectra of the ionized outflow. With supporting data from ground-based spectrographs, we are able to accurately measure the ratios of diagnostic emission lines such as [O III] λ5007, [O III] λ3727, [N II] λ6548, Hα, Hβ, [Ne V] λ3425, and [Ne III] λ3869. We fit the observed emission-line ratios using a range of ionization models, powered by active galactic nucleus (AGN) radiation and shocks, produced by the MAPPINGS code. We have determined that AGN radiation is likely the dominant ionization source. The outflow's density is estimated to be in the range n = 103-104 cm-3, the mass is ~6 × 106 M ⊙, and the metallicity is likely equal to or higher than solar. Compared with the typical outflows associated with more evolved radio jets, this young outflow is denser, less massive, and more metal rich. Multi-slit observations allow us to construct a two-dimensional velocity map of the outflow that shows a wide range of velocities with distinct velocity components, suggesting a wide-angle clumpy outflow. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO-11574. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Some of the

  4. Synthesis and Application of Aurophilic Poly(Cysteine and Poly(Cysteine-Containing Copolymers

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    David Ulkoski

    2017-10-01

    Full Text Available The redox capacity, as well as the aurophilicity of the terminal thiol side groups, in poly(Cysteine lend a unique characteristic to this poly(amino acid or polypeptide. There are two major application fields for this polymer: (i biomedical applications in drug delivery and surface modification of biomedical devices and (ii as coating for electrodes to enhance their electrochemical sensitivity. The intended application determines the synthetic route for p(Cysteine. Polymers to be used in biomedical applications are typically polymerized from the cysteine N-carboxyanhydride by a ring-opening polymerization, where the thiol group needs to be protected during the polymerization. Advances in this methodology have led to conditions under which the polymerization progresses as living polymerization, which allows for a strict control of the molecular architecture, molecular weight and polydispersity and the formation of block copolymers, which eventually could display polyphilic properties. Poly(Cysteine used as electrode coating is typically polymerized onto the electrode by cyclic voltammetry, which actually produces a continuous, pinhole-free film on the electrode via the formation of covalent bonds between the amino group of Cysteine and the carbon of the electrode. This resulting coating is chemically very different from the well-defined poly(Cysteine obtained by ring-opening polymerizations. Based on the structure of cysteine a significant degree of cross-linking within the coating deposited by cyclic voltammetry can be assumed. This manuscript provides a detailed discussion of the ring-opening polymerization of cysteine, a brief consideration of the role of glutathione, a key cysteine-containing tripeptide, and examples for the utilization of poly(Cysteine and poly(Cysteine-containing copolymers, in both, the biomedical as well as electrochemical realm.

  5. The Cysteine Protease–Cysteine Protease Inhibitor System Explored in Soybean Nodule Development

    Directory of Open Access Journals (Sweden)

    Marian Dorcas Quain

    2013-08-01

    Full Text Available Almost all protease families have been associated with plant development, particularly senescence, which is the final developmental stage of every organ before cell death. Proteolysis remobilizes and recycles nitrogen from senescent organs that is required, for example, seed development. Senescence-associated expression of proteases has recently been characterized using large-scale gene expression analysis seeking to identify and characterize senescence-related genes. Increasing activities of proteolytic enzymes, particularly cysteine proteases, are observed during the senescence of legume nodules, in which a symbiotic relationship between the host plant and bacteria (Rhizobia facilitate the fixation of atmospheric nitrogen. It is generally considered that cysteine proteases are compartmentalized to prevent uncontrolled proteolysis in nitrogen-fixing nodules. In addition, the activities of cysteine proteases are regulated by endogenous cysteine protease inhibitors called cystatins. These small proteins form reversible complexes with cysteine proteases, leading to inactivation. However, very little is currently known about how the cysteine protease-cysteine protease inhibitor (cystatin system is regulated during nodule development. Moreover, our current understanding of the expression and functions of proteases and protease inhibitors in nodules is fragmented. To address this issue, we have summarized the current knowledge and techniques used for studying proteases and their inhibitors including the application of “omics” tools, with a particular focus on changes in the cysteine protease-cystatin system during nodule development.

  6. Reduction of Guanosyl Radical by Cysteine and Cysteine-Glycine Studied by Time-Resolved CIDNP

    NARCIS (Netherlands)

    Morozova, O.B.; Kaptein, R.; Yurkovskaya, A.V.

    2012-01-01

    As a model for chemical DNA repair, reduction of guanosyl radicals in the reaction with cysteine or the dipeptide cysteine-glycine has been studied by time-resolved chemically induced dynamic nuclear polarization (CIDNP). Radicals were generated photochemically by pulsed laser irradiation of a

  7. Crystal Structure of Mammalian Cysteine dioxygenase: A Novel Mononuclear Iron Center for Cysteine Thiol Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Simmons,C.; Liu, Q.; Huang, Q.; Hao, Q.; Begley, T.; Karplus, P.; Stipanuk, M.

    2006-01-01

    Cysteine dioxygenase is a mononuclear iron-dependent enzyme responsible for the oxidation of cysteine with molecular oxygen to form cysteinesulfinate. This reaction commits cysteine to either catabolism to sulfate and pyruvate or to the taurine biosynthetic pathway. Cysteine dioxygenase is a member of the cupin superfamily of proteins. The crystal structure of recombinant rat cysteine dioxygenase has been determined to 1.5 Angstroms resolution, and these results confirm the canonical cupin {beta}-sandwich fold and the rare cysteinyl-tyrosine intramolecular crosslink (between Cys93 and Tyr157) seen in the recently reported murine cysteine dioxygenase structure. In contrast to the catalytically inactive mononuclear Ni(II) metallocenter present in the murine structure, crystallization of a catalytically competent preparation of rat cysteine dioxygenase revealed a novel tetrahedrally coordinated mononuclear iron center involving three histidines (His86, His88, and His140) and a water molecule. Attempts to acquire a structure with bound ligand using either co-crystallization or soaks with cysteine revealed the formation of a mixed disulfide involving Cys164 near the active site, which may explain previously observed substrate inhibition. This work provides a framework for understanding the molecular mechanisms involved in thiol dioxygenation and sets the stage for exploring the chemistry of both the novel mononuclear iron center and the catalytic role of the cysteinyl-tyrosine linkage.

  8. Reconstruction of Cysteine Biosynthesis Using Engineered Cysteine-Free and Methionine-Free Enzymes

    Science.gov (United States)

    Wang, Kendrick; Fujishima, Kosuke; Abe, Nozomi; Nakahigashi, Kenji; Endy, Drew; Rothschild, Lynn J.

    2016-01-01

    Ten of the proteinogenic amino acids can be generated abiotically while the remaining thirteen require biology for their synthesis. Paradoxically, the biosynthesis pathways observed in nature require enzymes that are made with the amino acids they produce. For example, Escherichia coli produces cysteine from serine via two enzymes that contain cysteine. Here, we substituted alternate amino acids for cysteine and also methionine, which is biosynthesized from cysteine, in serine acetyl transferase (CysE) and O-acetylserine sulfhydrylase (CysM). CysE function was rescued by cysteine-and-methionine-free enzymes and CysM function was rescued by cysteine-free enzymes. Structural modeling suggests that methionine stabilizes CysM and is present in the active site of CysM. Cysteine is not conserved among CysE and CysM protein orthologs, suggesting that cysteine is not functionally important for its own synthesis. Engineering biosynthetic enzymes that lack the amino acids being synthesized provides insights into the evolution of amino acid biosynthesis and pathways for bioengineering.

  9. Cysteine Biosynthesis Controls Serratia marcescens Phospholipase Activity.

    Science.gov (United States)

    Anderson, Mark T; Mitchell, Lindsay A; Mobley, Harry L T

    2017-08-15

    Serratia marcescens causes health care-associated opportunistic infections that can be difficult to treat due to a high incidence of antibiotic resistance. One of the many secreted proteins of S. marcescens is the PhlA phospholipase enzyme. Genes involved in the production and secretion of PhlA were identified by screening a transposon insertion library for phospholipase-deficient mutants on phosphatidylcholine-containing medium. Mutations were identified in four genes ( cyaA , crp , fliJ , and fliP ) that are involved in the flagellum-dependent PhlA secretion pathway. An additional phospholipase-deficient isolate harbored a transposon insertion in the cysE gene encoding a predicted serine O -acetyltransferase required for cysteine biosynthesis. The cysE requirement for extracellular phospholipase activity was confirmed using a fluorogenic phospholipase substrate. Phospholipase activity was restored to the cysE mutant by the addition of exogenous l-cysteine or O -acetylserine to the culture medium and by genetic complementation. Additionally, phlA transcript levels were decreased 6-fold in bacteria lacking cysE and were restored with added cysteine, indicating a role for cysteine-dependent transcriptional regulation of S. marcescens phospholipase activity. S. marcescens cysE mutants also exhibited a defect in swarming motility that was correlated with reduced levels of flhD and fliA flagellar regulator gene transcription. Together, these findings suggest a model in which cysteine is required for the regulation of both extracellular phospholipase activity and surface motility in S. marcescens IMPORTANCE Serratia marcescens is known to secrete multiple extracellular enzymes, but PhlA is unusual in that this protein is thought to be exported by the flagellar transport apparatus. In this study, we demonstrate that both extracellular phospholipase activity and flagellar function are dependent on the cysteine biosynthesis pathway. Furthermore, a disruption of cysteine

  10. VLBI structure of the QSO 3C286

    Science.gov (United States)

    Kus, A. J.; Marecki, A.; Neff, S.; Van Ardenne, A.; Wilkinson, P. N.

    1988-01-01

    Observations of the quasar 3C286 with the EVN at 609 and 1420 MHz are reported. Results are presented on source size, the steepening of the spectral index, the IC X-ray flux, and surface brightness temperature. It is concluded that 3C286 appears to be not as energetic as the other 3C sources of the class.

  11. π-Clamp-mediated cysteine conjugation

    Science.gov (United States)

    Zhang, Chi; Welborn, Matthew; Zhu, Tianyu; Yang, Nicole J.; Santos, Michael S.; van Voorhis, Troy; Pentelute, Bradley L.

    2016-02-01

    Site-selective functionalization of complex molecules is one of the most significant challenges in chemistry. Typically, protecting groups or catalysts must be used to enable the selective modification of one site among many that are similarly reactive, and general strategies that selectively tune the local chemical environment around a target site are rare. Here, we show a four-amino-acid sequence (Phe-Cys-Pro-Phe), which we call the ‘π-clamp’, that tunes the reactivity of its cysteine thiol for site-selective conjugation with perfluoroaromatic reagents. We use the π-clamp to selectively modify one cysteine site in proteins containing multiple endogenous cysteine residues. These examples include antibodies and cysteine-based enzymes that would be difficult to modify selectively using standard cysteine-based methods. Antibodies modified using the π-clamp retained binding affinity to their targets, enabling the synthesis of site-specific antibody-drug conjugates for selective killing of HER2-positive breast cancer cells. The π-clamp is an unexpected approach to mediate site-selective chemistry and provides new avenues to modify biomolecules for research and therapeutics.

  12. Synthesis and characterization of "1"3C_3-tristearin

    International Nuclear Information System (INIS)

    Wu Hangyu; Lin Lin; Li Lei; Chen Dazhou

    2011-01-01

    A highly efficient synthesis of "1"3C_3 labeled triglycerides of stearic acids from "1"3C_3-glycerol and stearic acids, by immobilized lipase-catalyzed in solvent-free medium was described. The structure of the product were characterized by fourier transform infrared spectrum (FT-IR), nuclear magnetic resonance (NMR), mass spectra (MS). The results showed that triglycerides of stearic acids contained three "1"3C atoms. The isotope abundance of "1"3C_3-tristearin was more than 99% and the yield was 80% of "1"3C_3-tristearin through calculation. Chemical purity (> 98%) was obtained by differential scanning calorimetry (DSC). (authors)

  13. Analysis list: NR3C1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NR3C1 Blood,Bone,Breast,Liver,Others,Prostate,Uterus + hg19 http://dbarchive.biosci...encedbc.jp/kyushu-u/hg19/target/NR3C1.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/NR3C1.5.tsv http:...//dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/NR3C1.10.tsv http://dbarchive.biosciencedbc.jp/kyu...shu-u/hg19/colo/NR3C1.Blood.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/NR3C1.Bone.tsv,http:...//dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/NR3C1.Breast.tsv,http://dbarchive.bi

  14. Analysis list: Nr3c1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Nr3c1 Adipocyte,Blood,Breast,Embryo,Embryonic fibroblast,Liver,Neural + mm9 http://dbarchive.bioscience...dbc.jp/kyushu-u/mm9/target/Nr3c1.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/ta...rget/Nr3c1.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Nr3c1.10.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/mm9/colo/Nr3c1.Adipocyte.tsv,http://dbarchive.biosciencedbc.jp.../kyushu-u/mm9/colo/Nr3c1.Blood.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Nr3c1.Breast.tsv,http://dbarchive.bioscience

  15. Peculiar morphology of the high-redshift radio galaxies 3C 13 and 3C 256 in subarcsecond seeing

    International Nuclear Information System (INIS)

    Le Fevre, O.; Hammer, F.; Nottale, L.; Mazure, A.; Christian, C.

    1988-01-01

    High-spatial-resolution imaging is presented for two radio galaxies from the 3C catalog, 3C 13 and 3C 256 with redshifts of 1.351 and 1.819, respectively. The excellent image quality obtained at CFHT, 0.6-arcsec FWHM for 3C 13 and 0.7-arcsec FWHM for 3C 256 in the R band, over long integration times, made it possible to resolve these distant galaxies into complex structures. As suggested by Le Fevre et al. (1987) for another source (the gravitational lens candidate 3C 324) an interpretation in terms of gravitational amplification by foreground galaxies or clusters of galaxies is proposed. 3C 13 appears to be the most serious candidate, since a foreground galaxy, with an absolute luminosity M(R) = 23.3 and a redshift z = 0.477, is only 3.9 in from the extended radio galaxy. 18 references

  16. Cysteine proteases as potential antigens in antiparasitic DNA vaccines

    DEFF Research Database (Denmark)

    Jørgensen, Louise von Gersdorff; Buchmann, Kurt

    2011-01-01

    En litteraturgennemgang af muligheder for at bruge cystein proteaser som antigener i antiparasitære vacciner.......En litteraturgennemgang af muligheder for at bruge cystein proteaser som antigener i antiparasitære vacciner....

  17. 21 CFR 184.1271 - L-Cysteine.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true L-Cysteine. 184.1271 Section 184.1271 Food and... Substances Affirmed as GRAS § 184.1271 L-Cysteine. (a) L-Cysteine is the chemical L-2-amino-3... of total L-cysteine per 100 parts of flour in dough as a dough strengthener as defined in § 170.3(o...

  18. 21 CFR 184.1272 - L-Cysteine monohydrochloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true L-Cysteine monohydrochloride. 184.1272 Section 184... Listing of Specific Substances Affirmed as GRAS § 184.1272 L-Cysteine monohydrochloride. (a) L-Cysteine... ingredient is used to supply up to 0.009 part of total L-cysteine per 100 parts of flour in dough as a dough...

  19. Evidence of complex magnetism in CePt3C

    International Nuclear Information System (INIS)

    Vejpravova, J.; Prokleska, J.; Danis, S.; Uhlirova, K.; Sechovsky, V.

    2006-01-01

    CePt 3 C has been synthesized and studied by powder X-ray diffraction (at RT), specific heat, resistivity and magnetization measurements at temperatures from RT down to 0.4K and in magnetic fields up to 10T. A possible scenario for the ground state of CePt 3 C based on the observed phenomena is proposed

  20. Role and efforts of T3C in corrosion economics

    International Nuclear Information System (INIS)

    Perrigo, L.D.; Appleman, B.R.; Pamer, R.I.; Thompson, J.L.

    1979-11-01

    The basic purpose of T3C activity is to show how to acquire specific corrosion cost information so that overall costs for doing business can be reduced. The scope of T3C is to accumulate data, appraise methods, develop recommended practices, promote knowledge and communicate relative to the economic evaluation of corrosion and counter corrosion techniques

  1. Characterization of methacetin-methoxy-"1"3C

    International Nuclear Information System (INIS)

    Lu Weijing; Lu Hao; Yang Weicheng; Liu Weixia; Li Shuai; Xu Zhongjie; Guan Liang; Zhu Chengmo; Chen Suyun; Jiang Lei

    2010-01-01

    Methacetin-methoxy-"1"3C was synthesized by using methanol-"1"3C with a novel method, and the characterization of it was performed using HPLC, LC-MS and "1HMNR. The results indicated that the synthetic was right. And the yield of methacetin-methoxy-"1"3C was 70.0% with 99% "1"3C abundance and 99.8% purity. Compared with the classical method, there was more benefit. The methacetin "1"3C-breath test was performed with the synthetic on the live mice, which showed a precise reflection of alteration of liver function in liver injury and functional recovery. (authors)

  2. L-Cysteine Metabolism and Fermentation in Microorganisms.

    Science.gov (United States)

    Takagi, Hiroshi; Ohtsu, Iwao

    L-Cysteine is an important amino acid both biologically and commercially. Although most amino acids are industrially produced by microbial fermentation, L-cysteine has been mainly produced by protein hydrolysis. Due to environmental and safety problems, synthetic or biotechnological products have been preferred in the market. Here, we reviewed L-cysteine metabolism, including biosynthesis, degradation, and transport, and biotechnological production (including both enzymatic and fermentation processes) of L-cysteine. The metabolic regulation of L-cysteine including novel sulfur metabolic pathways found in microorganisms is also discussed. Recent advancement in biochemical studies, genome sequencing, structural biology, and metabolome analysis has enabled us to use various approaches to achieve direct fermentation of L-cysteine from glucose. For example, worldwide companies began to supply L-cysteine and its derivatives produced by bacterial fermentation. These companies successfully optimized the original metabolism of their private strains. Basically, a combination of three factors should be required for improving L-cysteine fermentation: that is, (1) enhancing biosynthesis: overexpression of the altered cysE gene encoding feedback inhibition-insensitive L-serine O-acetyltransferase (SAT), (2) weakening degradation: knockout of the genes encoding L-cysteine desulfhydrases, and (3) exploiting export system: overexpression of the gene involved in L-cysteine transport. Moreover, we found that "thiosulfate" is much more effective sulfur source than commonly used "sulfate" for L-cysteine production in Escherichia coli, because thiosulfate is advantageous for saving consumption of NADPH and relating energy molecules.

  3. [Plant signaling peptides. Cysteine-rich peptides].

    Science.gov (United States)

    Ostrowski, Maciej; Kowalczyk, Stanisław

    2015-01-01

    Recent bioinformatic and genetic analyses of several model plant genomes have revealed the existence of a highly abundant group of signaling peptides that are defined as cysteine-rich peptides (CRPs). CRPs are usually in size between 50 and 90 amino acid residues, they are positively charged, and they contain 4-16 cysteine residues that are important for the correct conformational folding. Despite the structural differences among CRP classes, members from each class have striking similarities in their molecular properties and function. The present review presents the recent progress in research on signaling peptides from several families including: EPF/EPFL, SP11/SCR, PrsS, RALF, LURE, and some other peptides belonging to CRP group. There is convincing evidence indicating multiple roles for these CRPs as signaling molecules during the plant life cycle, ranging from stomata development and patterning, self-incompatibility, pollen tube growth and guidance, reproductive processes, and nodule formation.

  4. 17 CFR 270.3c-1 - Definition of beneficial ownership for certain 3(c)(1) funds.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Definition of beneficial... AND EXCHANGE COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.3c-1 Definition of beneficial ownership for certain 3(c)(1) funds. (a) As used in this section: (1) The term...

  5. Atomic-scale microstructures of Zr2Al3C4 and Zr3Al3C5 ceramics

    International Nuclear Information System (INIS)

    Lin, Z.J.; Zhuo, M.J.; He, L.F.; Zhou, Y.C.; Li, M.S.; Wang, J.Y.

    2006-01-01

    The microstructures of bulk Zr 2 Al 3 C 4 and Zr 3 Al 3 C 5 ceramics have been investigated using transmission electron microscopy and scanning transmission electron microscopy. These two carbides were determined to have a point group 6/mmm and a space group P6 3 /mmc using selected-area electron diffraction and convergent beam electron diffraction. The atomic-scale microstructures of Zr 2 Al 3 C 4 and Zr 3 Al 3 C 5 were investigated through high-resolution imaging and Z-contrast imaging. Furthermore, intergrowth between Zr 2 Al 3 C 4 and Zr 3 Al 3 C 5 was identified. Stacking faults in Zr 3 Al 3 C 5 were found to result from the insertion of an additional Zr-C layer. Cubic ZrC was occasionally identified to be incorporated in elongated Zr 3 Al 3 C 5 grains. In addition, Al may induce a twinned ZrC structure and lead to the formation of ternary zirconium aluminum carbides

  6. Privacy Issues of the W3C Geolocation API

    OpenAIRE

    Doty, Nick; Mulligan, Deirdre K.; Wilde, Erik

    2010-01-01

    The W3C's Geolocation API may rapidly standardize the transmission of location information on the Web, but, in dealing with such sensitive information, it also raises serious privacy concerns. We analyze the manner and extent to which the current W3C Geolocation API provides mechanisms to support privacy. We propose a privacy framework for the consideration of location information and use it to evaluate the W3C Geolocation API, both the specification and its use in the wild, and recommend s...

  7. The mitochondrial toxicity of cysteine-S-conjugates: Studies with pentachlorobutadienyl-L-cysteine

    International Nuclear Information System (INIS)

    Wallin, A.

    1990-01-01

    Nephrotoxic cysteine conjugates, arising from mercapturate biosynthesis, can perturb the mitochondrial membrane potential and calcium homeostasis in renal epithelial cells. Activation of these cysteine conjugates to reactive species by mitochondrial β-lyases results in covalent binding and mitochondrial damage. PCBC and related cysteine conjugates inhibit ADP-stimulated respiration in mitochondria respiring on alpha-ketoglutrate/malate and succinate indicating that both dehydrogenases may be targets. The respiratory inhibition is blocked by aminooxyacetic acid, an inhibitor of the β-lyase. Hence, metabolic activation is required implying that covalent binding of reactive intermediates may be important to the mitochondrial injury. Binding of 35 S-fragments has been found for 5 conjugates with varying degrees of mitochondrial toxicity. PCBC is more lipophilic and has a higher affinity for cellular membranes than other cysteine conjugates. PCBC rapidly depolarizes the inner membrane potential resulting in an inhibition of mitochondrial oxidative phosphorylation and calcium upon sequestration. Consequently, mitochondria and renal epithelial cells exposed to PCBC show a sudden release of calcium upon exposure to PCBC which is followed by a later increase in state 4 respiration leading to an inhibition of oxidative phosphorylation. The primary effect of other cysteine conjugates is an inhibition of the dehydrogenases, thus inhibiting state 3 respiration

  8. Transport properties at 3C-SiC interfaces

    OpenAIRE

    Eriksson, Gustav Jens Peter

    2011-01-01

    For years cubic (3C) silicon carbide (SiC) has been believed to be a very promising wide bandgap semiconductor for high frequency and high power electronics. However, 3C-SiC is fraught with large concentrations of various defects, which have so far hindered the achievement of the predicted properties at a macroscopic level. These defects have properties that are inherently nanoscale and that will have a strong influence on the electrical behavior of the material, particularly at interfaces c...

  9. W3C Geolocation API ur ett utvecklarperspektiv

    OpenAIRE

    Jönsson, Jesper

    2012-01-01

    The goal of this thesis is to investigate the W3C Geolocation API from a developer’s perspective, focused on whether it makes development of location-based applications more accessible to developers. This has been investigated by looking at available ways to locate, possible uses, the functionality offered, the necessary level of prior knowledge needed for a developer and requirements on developer tools. This has been achieved through studies in relevant areas, a thorough introduction to W3C ...

  10. Rethinking Cysteine Protective Groups: S-Alkylsulfonyl-l-Cysteines for Chemoselective Disulfide Formation.

    Science.gov (United States)

    Schäfer, Olga; Huesmann, David; Muhl, Christian; Barz, Matthias

    2016-12-12

    The ability to reversibly cross-link proteins and peptides grants the amino acid cysteine its unique role in nature as well as in peptide chemistry. We report a novel class of S-alkylsulfonyl-l-cysteines and N-carboxy anhydrides (NCA) thereof for peptide synthesis. The S-alkylsulfonyl group is stable against amines and thus enables its use under Fmoc chemistry conditions and the controlled polymerization of the corresponding NCAs yielding well-defined homo- as well as block co-polymers. Yet, thiols react immediately with the S-alkylsulfonyl group forming asymmetric disulfides. Therefore, we introduce the first reactive cysteine derivative for efficient and chemoselective disulfide formation in synthetic polypeptides, thus bypassing additional protective group cleavage steps. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. A modified stratified model for the 3C 273 jet

    International Nuclear Information System (INIS)

    Liu Wenpo; Shen Zhiqiang

    2009-01-01

    We present a modified stratified jet model to interpret the observed spectral energy distributions of knots in the 3C 273 jet. Based on the hypothesis of the single index of the particle energy spectrum at injection and identical emission processes among all the knots, the observed difference of spectral shape among different 3C 273 knots can be understood as a manifestation of the deviation of the equivalent Doppler factor of stratified emission regions in an individual knot from a characteristic one. The summed spectral energy distributions of all ten knots in the 3C 273 jet can be well fitted by two components: a low-energy component (radio to optical) dominated by synchrotron radiation and a high-energy component (UV, X-ray and γ-ray) dominated by inverse Compton scattering of the cosmic microwave background. This gives a consistent spectral index of α = 0.88 (S v ∝ v -α ) and a characteristic Doppler factor of 7.4. Assuming the average of the summed spectrum as the characteristic spectrum of each knot in the 3C 273 jet, we further get a distribution of Doppler factors. We discuss the possible implications of these results for the physical properties in the 3C 273 jet. Future GeV observations with GLAST could separate the γ-ray emission of 3C 273 from the large scale jet and the small scale jet (i.e. the core) through measuring the GeV spectrum.

  12. Pulse photolysis of NADH in the presence of cysteine

    International Nuclear Information System (INIS)

    Scheel, H.E.

    1976-01-01

    In the UV irradiation of NADH under anaerobic conditions, cysteine, which often acts as a radioprotective substance, has a sensitizing effect. With the aid of pulse photolysis, it was studied which reaction mechanisms in the presence or absence of cysteine are responsible for the damage to NADH in aqueous solution. In the absence of cysteine, the characteristic NADH absorption at 340 nm is reduced immediately after UV quanta have been absorbed by the adenine fraction of the molecules; in the presence of cysteine, a secondary reaction causes additional damage. The spectra of the intermediate products of NADH and cysteine have been recorded for different cysteine concentrations, and the reaction constants have been determined. These values suggest that the sensitizing effect is due to a reaction of NADH with radical anions produced by photolysis. (orig.) [de

  13. Modulation of ion transport across rat distal colon by cysteine

    Directory of Open Access Journals (Sweden)

    Martin eDiener

    2012-03-01

    Full Text Available The aim of this study was to identify the actions of stimulation of endogenous production of H2S by cysteine, the substrate for the two H2S-producing enzymes, cystathionin-beta-synthase and cystathionin-gamma-lyase, on ion transport across rat distal colon. Changes in short-circuit current (Isc induced by cysteine were measured in Ussing chambers. Free cysteine caused a concentration-dependent, transient fall in Isc, which was sensitive to amino-oxyacetate and beta-cyano-L-alanine, i.e. inhibitors of H2S-producing enzymes. In contrast, Na cysteinate evoked a biphasic change in Isc, i.e. an initial fall followed by a secondary increase, which was also reduced by these enzyme inhibitors. All responses were dependent on the presence of Cl- and inhibited by bumetanide, suggesting that free cysteine induces an inhibition of transcellular Cl- secretion, whereas Na cysteinate – after a transient inhibitory phase – activates anion secretion. The assumed reason for this discrepancy is a fall in the cytosolic pH induced by free cysteine, but not by Na cysteinate, as observed in isolated colonic crypts loaded with the pH-sensitive dye, BCECF. Intracellular acidification is known to inhibit epithelial K+ channels. Indeed, after preinhibition of basolateral K+ channels with tetrapentylammonium or Ba2+, the negative Isc induced by free cysteine was reduced significantly. In consequence, stimulation of endogenous H2S production by Na cysteinate causes, after a short inhibitory response, a delayed activation of anion secretion, which is missing in the case of free cysteine, probably due to the cytosolic acidification. In contrast, diallyl trisulfide, which is intracellularly converted to H2S, only evoked a monophasic increase in Isc without the initial fall observed with Na cysteinate. Consequently, time course and amount of produced H2S seem to strongly influence the functional response of the colonic epithelium evoked by this gasotransmitter.

  14. Protein modification by acrolein: Formation and stability of cysteine adducts

    OpenAIRE

    Cai, Jian; Bhatnagar, Aruni; Pierce, William M.

    2009-01-01

    The toxicity of the ubiquitous pollutant and endogenous metabolite, acrolein, is due in part to covalent protein modifications. Acrolein reacts readily with protein nucleophiles via Michael addition and Schiff base formation. Potential acrolein targets in protein include the nucleophilic side chains of cysteine, histidine, and lysine residues as well as the free amino terminus of proteins. Although cysteine is the most acrolein-reactive residue, cysteine-acrolein adducts are difficult to iden...

  15. Cysteine-containing peptides having antioxidant properties

    Science.gov (United States)

    Bielicki, John K [Castro Valley, CA

    2008-10-21

    Cysteine containing amphipathic alpha helices of the exchangeable apolipoproteins, as exemplified by apolipoprotein (apo) A-I.sub.Milano (R173C) and apoA-I.sub.Paris, (R151C) were found to exhibit potent antioxidant activity on phospholipid surfaces. The addition of a free thiol, at the hydrophobic/hydrophilic interface of an amphipathic alpha helix of synthetic peptides that mimic HDL-related proteins, imparts a unique antioxidant activity to these peptides which inhibits lipid peroxidation and protects phospholipids from water-soluble free radical initiators. These peptides can be used as therapeutic agents to combat cardiovascular disease, ischemia, bone disease and other inflammatory related diseases.

  16. Heterologous expression of Hordeum vulgare cysteine protease in yeast

    DEFF Research Database (Denmark)

    Rosenkilde, Anne Lind; Dionisio, Giuseppe; Holm, Preben B

    Cysteine Proteases accounts for more than 90 % of the total proteolytic activity in the degradation of barley seed storage proteins during germination. Several Cysteine proteases have been identified in barley. One of the key enzymes, Hordeum vulgare endoprotease B2 (HvEPB2) was cloned with and w......Cysteine Proteases accounts for more than 90 % of the total proteolytic activity in the degradation of barley seed storage proteins during germination. Several Cysteine proteases have been identified in barley. One of the key enzymes, Hordeum vulgare endoprotease B2 (HvEPB2) was cloned...

  17. Soft Cysteine Signaling Network: The Functional Significance of Cysteine in Protein Function and the Soft Acids/Bases Thiol Chemistry That Facilitates Cysteine Modification.

    Science.gov (United States)

    Wible, Ryan S; Sutter, Thomas R

    2017-03-20

    The unique biophysical and electronic properties of cysteine make this molecule one of the most biologically critical amino acids in the proteome. The defining sulfur atom in cysteine is much larger than the oxygen and nitrogen atoms more commonly found in the other amino acids. As a result of its size, the valence electrons of sulfur are highly polarizable. Unique protein microenvironments favor the polarization of sulfur, thus increasing the overt reactivity of cysteine. Here, we provide a brief overview of the endogenous generation of reactive oxygen and electrophilic species and specific examples of enzymes and transcription factors in which the oxidation or covalent modification of cysteine in those proteins modulates their function. The perspective concludes with a discussion of cysteine chemistry and biophysics, the hard and soft acids and bases model, and the proposal of the Soft Cysteine Signaling Network: a hypothesis proposing the existence of a complex signaling network governed by layered chemical reactivity and cross-talk in which the chemical modification of reactive cysteine in biological networks triggers the reorganization of intracellular biochemistry to mitigate spikes in endogenous or exogenous oxidative or electrophilic stress.

  18. W3C head Berners-Lee to be knighted

    CERN Multimedia

    Gross, G

    2004-01-01

    "Tim Berners-Lee, credited with inventing the World Wide Web and now director of the World Wide Web Consortium, will be named a knight commander, Order of the British Empire, by Queen Elizabeth II, the W3C announced Wednesday" (1 page)

  19. Synthetic of Zr2Al3C5 material

    International Nuclear Information System (INIS)

    Leela-Adisorn, U.; Yamaguchi, A.

    2005-01-01

    Synthesis method of Zr 2 Al 3 C 5 via solid state reaction between Al, ZrC and carbon powder was studied. Al-ZrC-C compact with equivalent mol ratio of Zr 2 Al 3 C 5 was heated up to 1600 C in Ar atmosphere for 1 h and 4 h but ZrC phase still existed as major phase with very small amount of Zr 2 Al 3 C 5 . Because ZrC started to oxidize at low temperature under very low oxygen partial pressure, the same mol ratio of Al-ZrC-C compact was heated at 1600 C in vacuum for 1 h as parallel test. After firing in vacuum, some carbon still exist with small amount of AlZrC 2 occurred with Zr 2 Al 3 C 5 as a main phase, but no ZrC was found. Different result from firing in Ar atmosphere and in vacuum had been discussed here. It was believed that very small amount of impurities in Ar had some effect on the formation of Al-Zr-C compound. The effect of very small amount of impurities in Ar was studied by thermal analysis (DTA/TG) and XRD. It was found that very small amount of impurities in Ar has effect on the reaction between Al, ZrC and carbon by diffusion through the surface and form Zr-C-O-N solid solution. This solid solution cannot differentiate from ZrC by XRD. With help of thermal analysis method (DTA/TG), Zr-C-O-N solid solution can be differentiated from ZrC. Therefore, synthesis of Al-Zr-C compound should be done in vacuum. Zr 2 Al 3 C 5 can be prepared from mixture of Al-ZrC-C with excess amount of Al at 1600 C for 1 h. (orig.)

  20. Cysteine peroxidase activity in rat blood plasma | Razygraev ...

    African Journals Online (AJOL)

    The rat plasma found to be able to accelerate greatly the H2O2-dependent oxidation of cysteine. The activity was a characteristic of a protein fraction precipitated at 30—44% ammonium sulfate saturation, and the specific activity in protein fraction was significantly higher than in plasma. Cysteine:H2O2 oxidoreductase ...

  1. Antimalarial effects of vinyl sulfone cysteine proteinase inhibitors.

    OpenAIRE

    Rosenthal, P J; Olson, J E; Lee, G K; Palmer, J T; Klaus, J L; Rasnick, D

    1996-01-01

    We evaluated the antimalarial effects of vinyl sulfone cysteine proteinase inhibitors. A number of vinyl sulfones strongly inhibited falcipain, a Plasmodium falciparum cysteine proteinase that is a critical hemoglobinase. In studies of cultured parasites, nanomolar concentrations of three vinyl sulfones inhibited parasite hemoglobin degradation, metabolic activity, and development. The antimalarial effects correlated with the inhibition of falcipain. Our results suggest that vinyl sulfones or...

  2. Lysosomal cysteine peptidases - Molecules signaling tumor cell death and survival.

    Science.gov (United States)

    Pišlar, Anja; Perišić Nanut, Milica; Kos, Janko

    2015-12-01

    Lysosomal cysteine peptidases - cysteine cathepsins - are general intracellular protein-degrading enzymes that control also a variety of specific physiological processes. They can trigger irreversible events leading to signal transduction and activation of signaling pathways, resulting in cell survival and proliferation or cell death. In cancer cells, lysosomal cysteine peptidases are involved in multiple processes during malignant progression. Their translocation from the endosomal/lysosomal pathway to nucleus, cytoplasm, plasma membrane and extracellular space enables the activation and remodeling of a variety of tumor promoting proteins. Thus, lysosomal cysteine peptidases interfere with cytokine/chemokine signaling, regulate cell adhesion and migration and endocytosis, are involved in the antitumor immune response and apoptosis, and promote cell invasion, angiogenesis and metastasis. Further, lysosomal cysteine peptidases modify growth factors and receptors involved in tyrosine kinase dependent pathways such as MAPK, Akt and JNK, thus representing key signaling tools for the activation of tumor cell growth and proliferation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Electrostatic influence of local cysteine environments on disulfide exchange kinetics.

    Science.gov (United States)

    Snyder, G H; Cennerazzo, M J; Karalis, A J; Field, D

    1981-11-10

    The ionic strength dependence of the bimolecular rate constant for reaction of the negative disulfide 5,5'-dithiobis (2-nitrobenzoic acid) with cysteines in fragments of naturally occurring proteins was determined by stopped-flow spectroscopy. The Debye-Hückel relationship was applied to determine the effective charge at the cysteine and thereby determine the extent to which nearby neighbors in the primary sequence influence the kinetics. Corrections for the secondary salt effect on cysteine pKs were determined by direct spectrometric pH titration of sulfhydryl groups or by observation of the ionic strength dependence of kinetics of cysteine reaction with the neutral disulfide 2,2'-dithiodipyridine. Quantitative expressions was verified by model studies with N-acetyl-cystein. At ionic strengths equal to or greater than 20 mM, the net charge at the polypeptide cysteine site is the sum of the single negative charge of the thiolate anion and the charges of the amino acids immediately preceding and following the cysteine in the primary sequence. At lower ionic strengths, more distant residues influence kinetics. At pH 7.0, 23 degree C, and an ionic strength of 20 mM, rate constants for reaction of the negative disulfide with a cysteine having two positive neighbors, one positive and one neutral neighbor, or two neutral neighbors are 132000, 3350, and 367 s-1 M-1, respectively. This corresponds to a contribution to the activation energy of 0.65- 1.1 kcal/mol per ion pair involved in collision between the cysteine and disulfide regions. The results permit the estimation that cysteine local environments may provide a means of achieving a 10(6)-fold range in rate constants in disulfide exchange reactions in random-coil proteins. This range may prove useful in developing strategies for directing disulfide pairing in synthetic proteins.

  4. Cysteine sulfoxide derivatives in Petiveria alliacea.

    Science.gov (United States)

    Kubec, R; Musah, R A

    2001-11-01

    Two diastereomers of S-benzyl-L-cysteine sulfoxide have been isolated from fresh roots of Petiveria alliacea. Their structures and absolute configurations have been determined by NMR, MALDI-HRMS, IR and CD spectroscopy and confirmed by comparison with authentic compounds. Both the R(S) and S(S) diastereomers of the sulfoxide are present in all parts of the plant (root, stem, and leaves) with the latter diastereomer being predominant. Their total content greatly varied in different parts of the plant between 0.07 and 2.97 mg g(-1) fr. wt, being by far the highest in the root. S-Benzylcysteine has also been detected in trace amounts (<10 microg g(-1) fr. wt) in all parts of the plant. This represents the first report of the presence of S-benzylcysteine derivatives in nature.

  5. Retaining in-gel zymographic activity of cysteine proteases via a cysteine-supplemented running buffer.

    Science.gov (United States)

    Vootukuri Reddy, Sreekanth; Philpott, Mike P; Trigiante, Giuseppe

    2016-10-01

    Zymography is a powerful technique to separate and identify different enzymatic activities on a standard acrylamide gel. For oxidation prone enzymes such as cysteine proteases however, the oxidizing species generated by electrolysis of the gel running buffer may result in partial or complete inactivation, thus compromising the final readout. This can be only partially remedied by subsequent treatment of the gel with reducing agents. We demonstrate the generation of reactive oxidizing species during electrophoresis and discovered that supplementation of the gel running buffer with a minimum of 5 mM cysteine prevents enzyme inactivation and allows retention of proteolytic activity as measured by zymography on model substrate N α-benzoyl-l-arginine p-nitroanilide, without at the same time altering the mobilities of the gel proteins. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Simultaneous electrochemical determination of L-cysteine and L-cysteine disulfide at carbon ionic liquid electrode.

    Science.gov (United States)

    Safavi, Afsaneh; Ahmadi, Raheleh; Mahyari, Farzaneh Aghakhani

    2014-04-01

    A linear sweep voltammetric method is used for direct simultaneous determination of L-cysteine and L-cysteine disulfide (cystine) based on carbon ionic liquid electrode. With carbon ionic liquid electrode as a high performance electrode, two oxidation peaks for L-cysteine (0.62 V) and L-cysteine disulfide (1.3 V) were observed with a significant separation of about 680 mV (vs. Ag/AgCl) in phosphate buffer solution (pH 6.0). The linear ranges were obtained as 1.0-450 and 5.0-700 μM and detection limits were estimated to be 0.298 and 4.258 μM for L-cysteine and L-cysteine disulfide, respectively. This composite electrode was applied for simultaneous determination of L-cysteine and L-cysteine disulfide in two real samples, artificial urine and nutrient broth. Satisfactory results were obtained which clearly indicate the applicability of the proposed electrode for simultaneous determination of these compounds in complex matrices.

  7. CHARACTERIZATION OF DANSYLATED CYSTEINE, GLUTATHIONE DISULFIDE, CYSTEINE AND CYSTINE BY NARROW BORE LIQUID CHROMATOGRAPHY/ELECTROSPRAY IONIZATION MASS SPECTROMETRY

    Science.gov (United States)

    A method using reversed phase high performance liquid chromatography/electrospray ionization-mass spectrometric (RP-LC/ESI-MS) method has been developed to confirm the identity of dansylated derivatives of cysteine and glutathione, and their respective dimers. Cysteine, GSH, CSSC...

  8. BeppoSAX Observations of 3C 279

    International Nuclear Information System (INIS)

    Maraschi, L.; Celotti, A.; Fossati, G.; Ghisellini, G.; Tagliaferri, G.; Pian, E.; Treves, A.; Raiteri, C.; Villata, M.; Bassani, L.; Cappi, M.; Chiappetti, L.; Comastri, A.; Frontera, F.; Giarrusso, S.; Grandi, P.; Molendi, S.; Palumbo, G.; Perola, C.; Salvati, M.; Tanzi, E.G.; Urry, C.M.

    1999-01-01

    We report on BeppoSAX AO1 Core Program observations of 3C 279, performed in January 1997. 3C 279 was found in a low state, with constant X-ray flux in the 5 observations. The spectra obtained with the LECS and MECS instruments combining the 5 observations are well fitted by a single power law with energy spectral index α = 0.64 ± 0.03 and Galactic absorption. The source is weakly detected by the PDS instrument. Comparison with simultaneous γ-ray data obtained by EGRET and with previous multifrequency measurements shows that the X-ray emission is well correlated with the γ-ray emission over long timescales

  9. BeppoSAX Observations of 3C 279

    Energy Technology Data Exchange (ETDEWEB)

    Maraschi, L.; Celotti, A.; Fossati, G.; Ghisellini, G.; Tagliaferri, G.; Pian, E.; Treves, A.; Raiteri, C.; Villata, M.; Bassani, L.; Cappi, M.; Chiappetti, L.; Comastri, A.; Frontera, F.; Giarrusso, S.; Grandi, P.; Molendi, S.; Palumbo, G.; Perola, C.; Salvati, M.; Tanzi, E.G.; Urry, C.M

    1999-01-01

    We report on BeppoSAX AO1 Core Program observations of 3C 279, performed in January 1997. 3C 279 was found in a low state, with constant X-ray flux in the 5 observations. The spectra obtained with the LECS and MECS instruments combining the 5 observations are well fitted by a single power law with energy spectral index {alpha} = 0.64 {+-} 0.03 and Galactic absorption. The source is weakly detected by the PDS instrument. Comparison with simultaneous {gamma}-ray data obtained by EGRET and with previous multifrequency measurements shows that the X-ray emission is well correlated with the {gamma}-ray emission over long timescales.

  10. The role of cysteine residues in the sulphate transporter, SHST1: construction of a functional cysteine-less transporter.

    Science.gov (United States)

    Howitt, Susan M

    2005-05-20

    We investigated the role of cysteine residues in the sulphate transporter, SHST1, with the aim of generating a functional cysteine-less variant. SHST1 contains five cysteine residues and none was essential for function. However, replacement of C421 resulted in a reduction in transport activity. Sulphate transport by C205 mutants was dependent on the size of the residue at this position. Alanine at position 205 resulted in a complete loss of function whereas leucine resulted in a 3-fold increase in sulphate transport relative to wild type SHST1. C205 is located in a putative intracellular loop and our results suggest that this loop may be important for sulphate transport. By replacing C205 with leucine and the other four cysteine residues with alanine, we constructed a cysteine-less variant of SHST1 that has transport characteristics indistinguishable from wild type. This construct will be useful for further structure and function studies of SHST1.

  11. 3C 254: the alignment effect and unification schemes

    Science.gov (United States)

    Bremer, M. N.

    1997-01-01

    3C 254 is a radio-loud quasar at z=0.734. Optical line and continuum emission from the underlying galaxy is clearly extended and aligned with the radio axis; the object shows the so-called `alignment effect' which is often seen in powerful radio galaxies. This is the clearest case yet of the continuum alignment effect in a radio-loud quasar. The object is one of the most lobe-dominated 3C quasars; the significance of the aligned emission in this source is discussed in terms of orientation-based unification schemes for radio-loud quasars and radio galaxies. 3C 254 is a very asymmetric radio source and it is shown that the radio structure on the side with the shortest nucleus-hotspot distance is interacting with the emission-line gas surrounding the quasar. It is also shown that the quasar is surrounded by an overdensity of faint objects, consistent with a cluster or group of galaxies around the object.

  12. The Trails of Superluminal Jet Components in 3C 111

    Science.gov (United States)

    Kadler, M.; Ros, E.; Perucho, M.; Kovalev, Y. Y.; Homan, D. C.; Agudo, I.; Kellermann, K. I.; Aller, M. F.; Aller, H. D.; Lister, M. L.; hide

    2007-01-01

    The parsec-scale radio jet of the broad-line radio galaxy 3C 111 has been monitored since 1995 as part of the 2cm Survey and MOJAVE monitoring observations conducted with the VLBA. Here, we present results from 18 epochs of VLBA observations of 3C 111 and from 18 years of radio flux density monitoring observations conducted at the University of Michigan. A major radio flux-density outburst of 3C 111 occurred in 1996 and was followed by a particularly bright plasma ejection associated with a superluminal jet component. This major event allows us to study a variety of processes associated with outbursts of radio-loud AGN in much greater detail than possible in other cases: the primary perturbation gives rise to the formation of a forward and a backward-shock, which both evolve in characteristically different ways and allow us to draw conclusions about the workflow of jet-production events; the expansion, acceleration and recollimation of the ejected jet plasma in an environment with steep pressure and density gradients are revealed; trailing components are formed in the wake of the primary perturbation as a result of Kelvin- Helmholtz instabilities from the interaction of the jet with the external medium. The jet-medium interaction is further scrutinized by the linear-polarization signature of jet components traveling along the jet and passing a region of steep pressure/density gradients.

  13. Probes of the catalytic site of cysteine dioxygenase.

    Science.gov (United States)

    Chai, Sergio C; Bruyere, John R; Maroney, Michael J

    2006-06-09

    The first major step of cysteine catabolism, the oxidation of cysteine to cysteine sulfinic acid, is catalyzed by cysteine dioxygenase (CDO). In the present work, we utilize recombinant rat liver CDO and cysteine derivatives to elucidate structural parameters involved in substrate recognition and x-ray absorption spectroscopy to probe the interaction of the active site iron center with cysteine. Kinetic studies using cysteine structural analogs show that most are inhibitors and that a terminal functional group bearing a negative charge (e.g. a carboxylate) is required for binding. The substrate-binding site has no stringent restrictions with respect to the size of the amino acid. Lack of the amino or carboxyl groups at the alpha-carbon does not prevent the molecules from interacting with the active site. In fact, cysteamine is shown to be a potent activator of the enzyme without being a substrate. CDO was also rendered inactive upon complexation with the metal-binding inhibitors azide and cyanide. Unlike many non-heme iron dioxygenases that employ alpha-keto acids as cofactors, CDO was shown to be the only dioxygenase known to be inhibited by alpha-ketoglutarate.

  14. L-Cysteine metabolism and its nutritional implications.

    Science.gov (United States)

    Yin, Jie; Ren, Wenkai; Yang, Guan; Duan, Jielin; Huang, Xingguo; Fang, Rejun; Li, Chongyong; Li, Tiejun; Yin, Yulong; Hou, Yongqing; Kim, Sung Woo; Wu, Guoyao

    2016-01-01

    L-Cysteine is a nutritionally semiessential amino acid and is present mainly in the form of L-cystine in the extracellular space. With the help of a transport system, extracellular L-cystine crosses the plasma membrane and is reduced to L-cysteine within cells by thioredoxin and reduced glutathione (GSH). Intracellular L-cysteine plays an important role in cellular homeostasis as a precursor for protein synthesis, and for production of GSH, hydrogen sulfide (H(2)S), and taurine. L-Cysteine-dependent synthesis of GSH has been investigated in many pathological conditions, while the pathway for L-cysteine metabolism to form H(2)S has received little attention with regard to prevention and treatment of disease in humans. The main objective of this review is to highlight the metabolic pathways of L-cysteine catabolism to GSH, H(2)S, and taurine, with special emphasis on therapeutic and nutritional use of L-cysteine to improve the health and well-being of animals and humans. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Overexpression of Catalase Diminishes Oxidative Cysteine Modifications of Cardiac Proteins.

    Directory of Open Access Journals (Sweden)

    Chunxiang Yao

    Full Text Available Reactive protein cysteine thiolates are instrumental in redox regulation. Oxidants, such as hydrogen peroxide (H2O2, react with thiolates to form oxidative post-translational modifications, enabling physiological redox signaling. Cardiac disease and aging are associated with oxidative stress which can impair redox signaling by altering essential cysteine thiolates. We previously found that cardiac-specific overexpression of catalase (Cat, an enzyme that detoxifies excess H2O2, protected from oxidative stress and delayed cardiac aging in mice. Using redox proteomics and systems biology, we sought to identify the cysteines that could play a key role in cardiac disease and aging. With a 'Tandem Mass Tag' (TMT labeling strategy and mass spectrometry, we investigated differential reversible cysteine oxidation in the cardiac proteome of wild type and Cat transgenic (Tg mice. Reversible cysteine oxidation was measured as thiol occupancy, the ratio of total available versus reversibly oxidized cysteine thiols. Catalase overexpression globally decreased thiol occupancy by ≥1.3 fold in 82 proteins, including numerous mitochondrial and contractile proteins. Systems biology analysis assigned the majority of proteins with differentially modified thiols in Cat Tg mice to pathways of aging and cardiac disease, including cellular stress response, proteostasis, and apoptosis. In addition, Cat Tg mice exhibited diminished protein glutathione adducts and decreased H2O2 production from mitochondrial complex I and II, suggesting improved function of cardiac mitochondria. In conclusion, our data suggest that catalase may alleviate cardiac disease and aging by moderating global protein cysteine thiol oxidation.

  16. Subcellular distribution of glutathione and cysteine in cyanobacteria.

    Science.gov (United States)

    Zechmann, Bernd; Tomasić, Ana; Horvat, Lucija; Fulgosi, Hrvoje

    2010-10-01

    Glutathione plays numerous important functions in eukaryotic and prokaryotic cells. Whereas it can be found in virtually all eukaryotic cells, its production in prokaryotes is restricted to cyanobacteria and proteobacteria and a few strains of gram-positive bacteria. In bacteria, it is involved in the protection against reactive oxygen species (ROS), osmotic shock, acidic conditions, toxic chemicals, and heavy metals. Glutathione synthesis in bacteria takes place in two steps out of cysteine, glutamate, and glycine. Cysteine is the limiting factor for glutathione biosynthesis which can be especially crucial for cyanobacteria, which rely on both the sufficient sulfur supply from the growth media and on the protection of glutathione against ROS that are produced during photosynthesis. In this study, we report a method that allows detection and visualization of the subcellular distribution of glutathione in Synechocystis sp. This method is based on immunogold cytochemistry with glutathione and cysteine antisera and computer-supported transmission electron microscopy. Labeling of glutathione and cysteine was restricted to the cytosol and interthylakoidal spaces. Glutathione and cysteine could not be detected in carboxysomes, cyanophycin granules, cell walls, intrathylakoidal spaces, periplasm, and vacuoles. The accuracy of the glutathione and cysteine labeling is supported by two observations. First, preadsorption of the antiglutathione and anticysteine antisera with glutathione and cysteine, respectively, reduced the density of the gold particles to background levels. Second, labeling of glutathione and cysteine was strongly decreased by 98.5% and 100%, respectively, in Synechocystis sp. cells grown on media without sulfur. This study indicates a strong similarity of the subcellular distribution of glutathione and cysteine in cyanobacteria and plastids of plants and provides a deeper insight into glutathione metabolism in bacteria.

  17. Effect of (L)-cysteine on acetaldehyde self-administration.

    Science.gov (United States)

    Peana, Alessandra T; Muggironi, Giulia; Fois, Giulia R; Zinellu, Manuel; Sirca, Donatella; Diana, Marco

    2012-08-01

    Acetaldehyde (ACD), the first metabolite of ethanol, has been implicated in several behavioural actions of alcohol, including its reinforcing effects. Recently, we reported that l-cysteine, a sequestrating agent of ACD, reduced oral ethanol self-administration and that ACD was orally self-administered. This study examined the effects of l-cysteine pre-treatment during the acquisition and maintenance phases of ACD (0.2%) self-administration as well as on the deprivation effect after ACD extinction and on a progressive ratio (PR) schedule of reinforcement. In a separate PR schedule of reinforcement, the effect of l-cysteine was assessed on the break-point produced by ethanol (10%). Furthermore, we tested the effect of l-cysteine on saccharin (0.2%) reinforcement. Wistar rats were trained to self-administer ACD by nose poking on a fixed ratio (FR1) schedule in 30-min daily sessions. Responses on an active nose-poke caused delivery of ACD solution, whereas responses on an inactive nose-poke had no consequences. l-cysteine reduced the acquisition (40 mg/kg), the maintenance and the deprivation effect (100 mg/kg) of ACD self-administration. Furthermore, at the same dose, l-cysteine (120 mg/kg) decreased both ACD and ethanol break point. In addition, l-cysteine was unable to suppress the different responses for saccharin, suggesting that its effect did not relate to an unspecific decrease in a general motivational state. Compared to saline, l-cysteine did not modify responses on inactive nose-pokes, suggesting an absence of a non-specific behavioural activation. Taken together, these results could support the hypotheses that ACD possesses reinforcing properties and l-cysteine reduces motivation to self-administer ACD. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Experience with Server Self Service Center (S3C)

    CERN Multimedia

    Sucik, J

    2009-01-01

    CERN has a successful experience with running Server Self Service Center (S3C) for virtual server provisioning which is based on Microsoft® Virtual Server 2005. With the introduction of Windows Server 2008 and its built-in hypervisor based virtualization (Hyper-V) there are new possibilities for the expansion of the current service. This paper describes the architecture of the redesigned virtual Server Self Service based on Hyper-V which provides dynamically scalable virtualized resources on demand as needed and outlines the possible implications on the future use of virtual machines at CERN.

  19. Experience with Server Self Service Center (S3C)

    International Nuclear Information System (INIS)

    Sucik, Juraj; Bukowiec, Sebastian

    2010-01-01

    CERN has a successful experience with running Server Self Service Center (S3C) for virtual server provisioning which is based on Microsoft (registered) Virtual Server 2005. With the introduction of Windows Server 2008 and its built-in hypervisor based virtualization (Hyper-V) there are new possibilities for the expansion of the current service. This paper describes the architecture of the redesigned virtual Server Self Service based on Hyper-V which provides dynamically scalable virtualized resources on demand as needed and outlines the possible implications on the future use of virtual machines at CERN.

  20. Cysteine-Rich Peptide Family with Unusual Disulfide Connectivity from Jasminum sambac.

    Science.gov (United States)

    Kumari, Geeta; Serra, Aida; Shin, Joon; Nguyen, Phuong Q T; Sze, Siu Kwan; Yoon, Ho Sup; Tam, James P

    2015-11-25

    Cysteine-rich peptides (CRPs) are natural products with privileged peptidyl structures that represent a potentially rich source of bioactive compounds. Here, the discovery and characterization of a novel plant CRP family, jasmintides from Jasminum sambac of the Oleaceae family, are described. Two 27-amino acid jasmintides (jS1 and jS2) were identified at the gene and protein levels. Disulfide bond mapping of jS1 by mass spectrometry and its confirmation by NMR spectroscopy revealed disulfide bond connectivity of C-1-C-5, C-2-C-4, and C-3-C-6, a cystine motif that has not been reported in plant CRPs. Structural determination showed that jS1 displays a well-defined structure framed by three short antiparallel β-sheets. Genomic analysis showed that jasmintides share a three-domain precursor arrangement with a C-terminal mature domain preceded by a long pro-domain of 46 residues and an intron cleavage site between the signal sequence and pro-domain. The compact cysteine-rich structure together with an N-terminal pyroglutamic acid residue confers jasmintides high resistance to heat and enzymatic degradation, including exopeptidase treatment. Collectively, these results reveal a new plant CRP structure with an unusual cystine connectivity, which could be useful as a scaffold for designing peptide drugs.

  1. Clusters of galaxies associated with quasars. I. 3C 206

    International Nuclear Information System (INIS)

    Ellingson, E.; Yee, H.K.C.; Green, R.F.; Kinman, T.D.

    1989-01-01

    Multislit spectroscopy and three-color CCD photometry of the galaxies in the cluster associated with the quasar 3C 206 (PKS 0837-12) at z = 0.198 are presented. This cluster is the richest environment of any low-redshift quasar observed in an Abell richness class 1 cluster. The cluster has a very flattened structure and a very concentrated core about the quasar. Most of the galaxies in this field have colors and luminosities consistent with normal galaxies at this redshift. The background-corrected blue fraction of galaxies is consistent with values for other rich clusters. The existence of several blue galaxies in the concentrated cluster core is an anomaly for a region of such high galaxy density, however, suggesting the absence of a substantial intracluster medium. This claim is supported by the Fanaroff-Riley (1974) class II morphology of the radio source. The velocity dispersion calculated from 11 spectroscopically confirmed cluster members is 500 + or - 110 km/s, which is slightly lower than the average for Abell class 1 clusters. A high frequency of interaction between the quasar host galaxy and cluster core members at low relative velocities, and a low intracluster gas pressure, may comprise a favorable environment for quasar activity. The properties of the cluster of galaxies associated with 3C 206 are consistent with this model. 59 refs

  2. Developing novel anthelmintics from plant cysteine proteinases

    Directory of Open Access Journals (Sweden)

    Stepek Gillian

    2008-09-01

    Full Text Available Abstract Intestinal helminth infections of livestock and humans are predominantly controlled by treatment with three classes of synthetic drugs, but some livestock nematodes have now developed resistance to all three classes and there are signs that human hookworms are becoming less responsive to the two classes (benzimidazoles and the nicotinic acetylcholine agonists that are licensed for treatment of humans. New anthelmintics are urgently needed, and whilst development of new synthetic drugs is ongoing, it is slow and there are no signs yet that novel compounds operating through different modes of action, will be available on the market in the current decade. The development of naturally-occurring compounds as medicines for human use and for treatment of animals is fraught with problems. In this paper we review the current status of cysteine proteinases from fruits and protective plant latices as novel anthelmintics, we consider some of the problems inherent in taking laboratory findings and those derived from folk-medicine to the market and we suggest that there is a wealth of new compounds still to be discovered that could be harvested to benefit humans and livestock.

  3. Cloning and characterization of a novel cysteine protease gene ...

    Indian Academy of Sciences (India)

    PRAKASH KUMAR

    Cysteine proteases can be found in the animal and plant kingdoms as well as in some viruses and bacteria. They have been implemented in many ..... in developing resistance against pathogens and insects in other crops. Acknowledgments.

  4. Reversible targeting of noncatalytic cysteines with chemically tuned electrophiles

    DEFF Research Database (Denmark)

    Serafimova, Iana M; Pufall, Miles A; Krishnan, Shyam

    2012-01-01

    Targeting noncatalytic cysteine residues with irreversible acrylamide-based inhibitors is a powerful approach for enhancing pharmacological potency and selectivity. Nevertheless, concerns about off-target modification motivate the development of reversible cysteine-targeting strategies. Here we...... of these electrophiles into a noncovalent kinase-recognition scaffold produced slowly dissociating, covalent inhibitors of the p90 ribosomal protein S6 kinase RSK2. A cocrystal structure revealed specific noncovalent interactions that stabilize the complex by positioning the electrophilic carbon near the targeted...

  5. Cysteine homeostasis plays an essential role in plant immunity.

    Science.gov (United States)

    Álvarez, Consolación; Bermúdez, M Ángeles; Romero, Luis C; Gotor, Cecilia; García, Irene

    2012-01-01

    Cysteine is the metabolic precursor of essential biomolecules such as vitamins, cofactors, antioxidants and many defense compounds. The last step of cysteine metabolism is catalysed by O-acetylserine(thiol)lyase (OASTL), which incorporates reduced sulfur into O-acetylserine to produce cysteine. In Arabidopsis thaliana, the main OASTL isoform OAS-A1 and the cytosolic desulfhydrase DES1, which degrades cysteine, contribute to the cytosolic cysteine homeostasis. • Meta-analysis of the transcriptomes of knockout plants for OAS-A1 and for DES1 show a high correlation with the biotic stress series in both cases. • The study of the response of knockout mutants to plant pathogens shows that des1 mutants behave as constitutive systemic acquired resistance mutants, with high resistance to biotrophic and necrotrophic pathogens, salicylic acid accumulation and WRKY54 and PR1 induction, while oas-a1 knockout mutants are more sensitive to biotrophic and necrotrophic pathogens. However, oas-a1 knockout mutants lack the hypersensitive response associated with the effector-triggered immunity elicited by Pseudomonas syringae pv. tomato DC3000 avrRpm1. • Our results highlight the role of cysteine as a crucial metabolite in the plant immune response. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  6. Synthesis, antioxidative and whitening effects of novel cysteine derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Ji Hoon; Kim, Kyoung Mi; Jeong, Yoon Ju; Park, Young Min; Lee, Jae Young; Park, Soo Nam [Dept. of Fine Chemistry, Cosmetic R and D Center, Cosmetic Industry Coupled Collaboration Center, Seoul National University of Science and Technology, Seoul (Korea, Republic of); Park, Jino [Daebong LS. Ltd, Incheon (Korea, Republic of)

    2017-01-15

    Recently, development of biocompatibility functional cosmetic agents as antioxidant or whitening agent has increased. In this study, synthetic cysteine derivatives (DBLS-21, -24, and -33) were developed containing syringic acid and cysteine moieties (l-cysteine ethyl ester, N-acetyl cysteine methyl ester, and N-acetyl cysteine ethyl ester), and their antioxidative and whitening activities were evaluated. The cellular protective effect (τ{sub 50}) of DBLS-21 was 51.1 min at 50 μM on {sup 1}O{sub 2} -induced hemolysis of erythrocytes. This activity was slightly higher than that of α-tocopherol (43.6 min) as a lipophilic antioxidant. In the melanogenesis inhibitory effect, DBLS-21, -24, and -33 was 1.6-, 1.8-, and 2.5-fold higher than arbutin, respectively. In particular, DBLS-21 and -33 was 112.8- and 6.1-fold higher than arbutin, respectively (293.4 μM) on tyrosinase inhibition activity (IC{sub 50} ). But DBLS-24 had no tyrosinase inhibitory activity. These results suggest that cysteine derivatives possess potential for use as an antioxidant agent (DBLS-21) and whitening agents (all derivatives) in cosmetics.

  7. Synthesis, antioxidative and whitening effects of novel cysteine derivatives

    International Nuclear Information System (INIS)

    Ha, Ji Hoon; Kim, Kyoung Mi; Jeong, Yoon Ju; Park, Young Min; Lee, Jae Young; Park, Soo Nam; Park, Jino

    2017-01-01

    Recently, development of biocompatibility functional cosmetic agents as antioxidant or whitening agent has increased. In this study, synthetic cysteine derivatives (DBLS-21, -24, and -33) were developed containing syringic acid and cysteine moieties (l-cysteine ethyl ester, N-acetyl cysteine methyl ester, and N-acetyl cysteine ethyl ester), and their antioxidative and whitening activities were evaluated. The cellular protective effect (τ_5_0) of DBLS-21 was 51.1 min at 50 μM on "1O_2 -induced hemolysis of erythrocytes. This activity was slightly higher than that of α-tocopherol (43.6 min) as a lipophilic antioxidant. In the melanogenesis inhibitory effect, DBLS-21, -24, and -33 was 1.6-, 1.8-, and 2.5-fold higher than arbutin, respectively. In particular, DBLS-21 and -33 was 112.8- and 6.1-fold higher than arbutin, respectively (293.4 μM) on tyrosinase inhibition activity (IC_5_0 ). But DBLS-24 had no tyrosinase inhibitory activity. These results suggest that cysteine derivatives possess potential for use as an antioxidant agent (DBLS-21) and whitening agents (all derivatives) in cosmetics

  8. Single ferromagnetic behaviour of nanopowders with Fe3C

    Czech Academy of Sciences Publication Activity Database

    David, Bohumil; Zbořil, R.; Mashlan, M.; Grygar, Tomáš; Dumitrache, F.; Schneeweiss, Oldřich

    2006-01-01

    Roč. 304, č. 2 (2006), e787-e789 ISSN 0304-8853. [International Symposium on Soft Magnetic Materials /17./. Bratislava, 07.09.2005-09.09.2005] R&D Projects: GA ČR GA202/04/0221; GA MŠk 1M0512 Institutional research plan: CEZ:AV0Z20410507; CEZ:AV0Z40320502 Keywords : synthesis * nanopowder * Fe3C Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.212, year: 2006 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TJJ-4JJ27YM-5&_user=625109&_coverDate=09%2F30%2F2006&_alid=501264124&_rdoc=2&_fmt=summary&_orig=search&_cdi=5312&_sort=d&_st=4&_docanchor=&_acct=C000031719&_version=1&_urlVersion=0&_userid=625109&md5=30fafcdb895bbb548857aa25426ae131

  9. Development of potent inhibitors of the coxsackievirus 3C protease

    International Nuclear Information System (INIS)

    Lee, Eui Seung; Lee, Won Gil; Yun, Soo-Hyeon; Rho, Seong Hwan; Im, Isak; Yang, Sung Tae; Sellamuthu, Saravanan; Lee, Yong Jae; Kwon, Sun Jae; Park, Ohkmae K.; Jeon, Eun-Seok; Park, Woo Jin; Kim, Yong-Chul

    2007-01-01

    Coxsackievirus B3 (CVB3) 3C protease (3CP) plays essential roles in the viral replication cycle, and therefore, provides an attractive therapeutic target for treatment of human diseases caused by CVB3 infection. CVB3 3CP and human rhinovirus (HRV) 3CP have a high degree of amino acid sequence similarity. Comparative modeling of these two 3CPs revealed one prominent distinction; an Asn residue delineating the S2' pocket in HRV 3CP is replaced by a Tyr residue in CVB3 3CP. AG7088, a potent inhibitor of HRV 3CP, was modified by substitution of the ethyl group at the P2' position with various hydrophobic aromatic rings that are predicted to interact preferentially with the Tyr residue in the S2' pocket of CVB3 3CP. The resulting derivatives showed dramatically increased inhibitory activities against CVB3 3CP. In addition, one of the derivatives effectively inhibited the CVB3 proliferation in vitro

  10. Measuring site occupancy: a new perspective on cysteine oxidation.

    Science.gov (United States)

    Rogowska-Wrzesinska, Adelina; Wojdyla, Katarzyna; Williamson, James; Roepstorff, Peter

    2014-10-01

    Site occupancy is an extremely important aspect of quantification of protein modifications. Knowing the degree of modification of each oxidised cysteine residue is critical to understanding the biological role of these modifications. Yet modification site occupancy is very often overlooked, in part because there are very few analytical tools that allow such measurements. Here we present a new strategy, which provides quantitative analysis of cysteine S-nitrosylation (SNO) and S-sulfenylation (SOH) simultaneously at the resolution of single cysteine and allows for determination of relative oxidation occupancy of the modification site. We show that, on one hand, heavily modified cysteines are not necessarily involved in the response to oxidative stress. On the other hand residues with low modification level can be dramatically affected by mild oxidative imbalance. We make use of high resolution mass spectrometry. The method relies on differential reduction of "total" cysteines, SNO cysteines and SOH cysteines with TCEP, sodium ascorbate and sodium arsenite respectively followed by iodoTMT(TM) alkylation. Enrichment of iodoTMT(TM)-containing peptides is performed using anti-TMT antibody. In vivo model of mild oxidative stress in Escherichia coli is used. To induce endogenous SNO bacteria were grown anaerobically in minimal media supplemented with fumarate or nitrate. Short-term treatment with submilimolar levels of hydrogen peroxide were used to induce SOH. We have quantified 114 SNO/SOH modified peptides corresponding to 90 proteins. Only 6 modified peptides changed significantly under mild oxidative stress. Quantitative information allowed us to determine relative modification site occupancy of each identified modified residue and pin point heavily modified ones. The method proved to be precise and sensitive enough to detect and quantify endogenous levels of oxidative stress on proteome-wide scale and brings a new perspective on the role of the modification site

  11. On the Dynamical Behavior of the Cysteine Dioxygenase-l-Cysteine Complex in the Presence of Free Dioxygen and l-Cysteine.

    Science.gov (United States)

    Pietra, Francesco

    2017-11-01

    In this work, viable models of cysteine dioxygenase (CDO) and its complex with l-cysteine dianion were built for the first time, under strict adherence to the crystal structure from X-ray diffraction studies, for all atom molecular dynamics (MD). Based on the CHARMM36 FF, the active site, featuring an octahedral dummy Fe(II) model, allowed us observing water exchange, which would have escaped attention with the more popular bonded models. Free dioxygen (O 2 ) and l-cysteine, added at the active site, could be observed being expelled toward the solvating medium under Random Accelerated Molecular Dynamics (RAMD) along major and minor pathways. Correspondingly, free dioxygen (O 2 ), added to the solvating medium, could be observed to follow the same above pathways in getting to the active site under unbiased MD. For the bulky l-cysteine, 600 ns of trajectory were insufficient for protein penetration, and the molecule was stuck at the protein borders. These models pave the way to free energy studies of ligand associations, devised to better clarify how this cardinal enzyme behaves in human metabolism. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  12. Structure and Properties of the Nonface-Spiral Fullerenes T-C380, D3-C384, D3-C440, and D3-C672 and Their Halma and Leapfrog Transforms

    DEFF Research Database (Denmark)

    Wirz, Lukas; Tonner, Ralf; Avery, James Emil

    2013-01-01

    The structure and properties of the three smallest nonface-spiral (NS) fullerenes NS-T-C380, NS-D3-C384, NS-D3-C440, and the first isolated pentagon NS-fullerene, NS-D3-C672, are investigated in detail. They are constructed by either a generalized face-spiral algorithm or by vertex insertions......-fullerenes compared to C60, but, as expected, in a lower stability than most stable isomers. None of the many investigated halma transforms on nonspiral fullerenes, NS-T-C380, NS-D3-C384, NS-D3-C440, and NS-D3-C672, admit any spirals, and we conjecture that all halma transforms of NS-fullerenes belong to the class...

  13. Biotin Switch Assays for Quantitation of Reversible Cysteine Oxidation.

    Science.gov (United States)

    Li, R; Kast, J

    2017-01-01

    Thiol groups in protein cysteine residues can be subjected to different oxidative modifications by reactive oxygen/nitrogen species. Reversible cysteine oxidation, including S-nitrosylation, S-sulfenylation, S-glutathionylation, and disulfide formation, modulate multiple biological functions, such as enzyme catalysis, antioxidant, and other signaling pathways. However, the biological relevance of reversible cysteine oxidation is typically underestimated, in part due to the low abundance and high reactivity of some of these modifications, and the lack of methods to enrich and quantify them. To facilitate future research efforts, this chapter describes detailed procedures to target the different modifications using mass spectrometry-based biotin switch assays. By switching the modification of interest to a biotin moiety, these assays leverage the high affinity between biotin and avidin to enrich the modification. The use of stable isotope labeling and a range of selective reducing agents facilitate the quantitation of individual as well as total reversible cysteine oxidation. The biotin switch assay has been widely applied to the quantitative analysis of S-nitrosylation in different disease models and is now also emerging as a valuable research tool for other oxidative cysteine modifications, highlighting its relevance as a versatile, robust strategy for carrying out in-depth studies in redox proteomics. © 2017 Elsevier Inc. All rights reserved.

  14. Geoscience Australia Publishes Sample Descriptions using W3C standards

    Science.gov (United States)

    Car, N. J.; Cox, S. J. D.; Bastrakova, I.; Wyborn, L. A.

    2017-12-01

    The recent revision of the W3C Semantic Sensor Network Ontology (SSN) has focused on three key concerns: Extending the scope of the ontology to include sampling and actuation as well as observation and sensing Modularizing the ontology into a simple core with few classes and properties and little formal axiomatization, supplemented by additional modules that formalize the semantics and extend the scope Alignments with several existing applications and upper ontologies These enhancements mean that SSN can now be used as the basis for publishing descriptions of geologic samples as Linked Data. Geoscience Australia maintains a database of about three million samples, collected over 50 years through projects from ocean core, terrestrial rock and hydrochemistry borehole projects, almost all of which are held in in the special-purpose GA samples repository. Access to descriptions of these samples as Linked Data has recently been enabled. The sample descriptions can be viewed in various machine-readable formalizations, including IGSN (XML & RDF), Dublin Core (XML & RDF) and SSN (RDF), as well as web landing-pages for people. Of particular importance is the support for encoding relationships between samples, and between samples and surveys, boreholes, and traverses which they are related to, as well as between samples processed for analytical purposes and their parents, siblings, and back to the original field samples. The SSN extension for Sample Relationships provides an extensible, semantically rich mechanism to capture any relationship necessary to explain the provenance of observation results obtained from samples. Sample citation is facilitated through the use of URI-based persistent identifiers which resolve to samples' landing pages. The sample system also allows PROV pingbacks to be received for samples when users of them record provenance for their actions.

  15. Cysteine peptidases and their inhibitors in breast and genital cancer.

    Directory of Open Access Journals (Sweden)

    Magdalena Milan

    2010-11-01

    Full Text Available Cysteine proteinases and their inhibitors probably play the main role in carcinogenesis and metastasis. The metastasis process need external proteolytic activities that pass several barriers which are membranous structures of the connective tissue which includes, the basement membrane of blood vessels. Activities of the proteinases are regulated by endogenous inhibitors and activators. The imbalance between cysteine proteinases and cystatins seems to be associated with an increase in metastatic potential in some tumors. It has also been reported that proteinase inhibitors, specific antibodies for these enzymes and inhibition of the urokinase receptor may prevent cancer cell invasion. Some proteinase inhibitor could serve as agents for cancer treatment.

  16. Identification of a novel homozygous mutation, TMPRSS3: c.535G>A, in a Tibetan family with autosomal recessive non-syndromic hearing loss.

    Directory of Open Access Journals (Sweden)

    Dongyan Fan

    Full Text Available Different ethnic groups have distinct mutation spectrums associated with inheritable deafness. In order to identify the mutations responsible for congenital hearing loss in the Tibetan population, mutation screening for 98 deafness-related genes by microarray and massively parallel sequencing of captured target exons was conducted in one Tibetan family with familiar hearing loss. A homozygous mutation, TMPRSS3: c.535G>A, was identified in two affected brothers. Both parents are heterozygotes and an unaffected sister carries wild type alleles. The same mutation was not detected in 101 control Tibetan individuals. This missense mutation results in an amino acid change (p.Ala179Thr at a highly conserved site in the scavenger receptor cysteine rich (SRCR domain of the TMPRSS3 protein, which is essential for protein-protein interactions. Thus, this mutation likely affects the interactions of this transmembrane protein with extracellular molecules. According to our bioinformatic analyses, the TMPRSS3: c.535G>A mutation might damage protein function and lead to hearing loss. These data suggest that the homozygous mutation TMPRSS3: c.535G>A causes prelingual hearing loss in this Tibetan family. This is the first TMPRSS3 mutation found in the Chinese Tibetan population.

  17. Cysteine-free peptides in scorpion venom: geographical distribution ...

    African Journals Online (AJOL)

    GRACE

    2006-12-29

    Dec 29, 2006 ... In 1993, the first cysteine-free peptide was isolated from scorpion venom. ..... Venom is produced by 2 venom glands in the tail and stored in 2 ... The resistance of a variety of bacterial micro-organisms .... Biopolymers 55: 4-30.

  18. A Serendipitous Formation of a Cysteine-bridged Disaccharide

    African Journals Online (AJOL)

    NICO

    O-acetyl-b-D-glucopyranosylisothiouronium salt and the iodide or tosyl derivatives of L-serine,3 the desulfurization of disulfide- linked glycosyl cysteine derivatives,4 Lewis acid-catalyzed glycosylation,5,6 and solid phase glycosylation.7. Glycosylation of amino acids has previously relied on the use of amino acids protected ...

  19. Isolation of recombinant cysteine dioxygenase protein from Trichophyton mentagrophytes

    Czech Academy of Sciences Publication Activity Database

    Kašperová, A.; Kunert, J.; Horynová, M.; Weigl, E.; Sebela, M.; Lenobel, René; Raška, M.

    2011-01-01

    Roč. 54, č. 5 (2011), E456-E462 ISSN 0933-7407 R&D Projects: GA ČR GA301/08/1649 Institutional research plan: CEZ:AV0Z50380511 Keywords : Cysteine dioxygenase * dermatophytes * recombinant protein * keratinolytic fungi * cDNA Subject RIV: CE - Biochemistry Impact factor: 2.247, year: 2011

  20. Cysteine Protease Inhibitors as Chemotherapy: Lessons from a Parasite Target

    Science.gov (United States)

    Selzer, Paul M.; Pingel, Sabine; Hsieh, Ivy; Ugele, Bernhard; Chan, Victor J.; Engel, Juan C.; Bogyo, Matthew; Russell, David G.; Sakanari, Judy A.; McKerrow, James H.

    1999-09-01

    Papain family cysteine proteases are key factors in the pathogenesis of cancer invasion, arthritis, osteoporosis, and microbial infections. Targeting this enzyme family is therefore one strategy in the development of new chemotherapy for a number of diseases. Little is known, however, about the efficacy, selectivity, and safety of cysteine protease inhibitors in cell culture or in vivo. We now report that specific cysteine protease inhibitors kill Leishmania parasites in vitro, at concentrations that do not overtly affect mammalian host cells. Inhibition of Leishmania cysteine protease activity was accompanied by defects in the parasite's lysosome/endosome compartment resembling those seen in lysosomal storage diseases. Colocalization of anti-protease antibodies with biotinylated surface proteins and accumulation of undigested debris and protease in the flagellar pocket of treated parasites were consistent with a pathway of protease trafficking from flagellar pocket to the lysosome/endosome compartment. The inhibitors were sufficiently absorbed and stable in vivo to ameliorate the pathology associated with a mouse model of Leishmania infection.

  1. Chemical detection of cysteine-rich circular petides in selected ...

    African Journals Online (AJOL)

    Cysteine-rich circular peptides (CRCs) comprise a large family of gene encoded and low molecular weight polypeptides that has recently engaged the attention of scientists. This class of peptides exhibit a continuous circular configuration and a cystine knot backbone, which defines their resilient nature-directed structural ...

  2. Targeting cysteine proteases in trypanosomatid disease drug discovery.

    Science.gov (United States)

    Ferreira, Leonardo G; Andricopulo, Adriano D

    2017-12-01

    Chagas disease and human African trypanosomiasis are endemic conditions in Latin America and Africa, respectively, for which no effective and safe therapy is available. Efforts in drug discovery have focused on several enzymes from these protozoans, among which cysteine proteases have been validated as molecular targets for pharmacological intervention. These enzymes are expressed during the entire life cycle of trypanosomatid parasites and are essential to many biological processes, including infectivity to the human host. As a result of advances in the knowledge of the structural aspects of cysteine proteases and their role in disease physiopathology, inhibition of these enzymes by small molecules has been demonstrated to be a worthwhile approach to trypanosomatid drug research. This review provides an update on drug discovery strategies targeting the cysteine peptidases cruzain from Trypanosoma cruzi and rhodesain and cathepsin B from Trypanosoma brucei. Given that current chemotherapy for Chagas disease and human African trypanosomiasis has several drawbacks, cysteine proteases will continue to be actively pursued as valuable molecular targets in trypanosomatid disease drug discovery efforts. Copyright © 2017. Published by Elsevier Inc.

  3. Chemoselective PEGylation of Cysteine Analogs of Human Basic ...

    African Journals Online (AJOL)

    Purpose: To improve the stability and bioactivity of human basic fibroblast growth factor (hbFGF) by site-specific pegylation. Methods: Four new mutants of hbFGF were designed with substituted Asp68, Lys77, Glu78 and Arg81 with cysteine with the aid of bioinformatics technique, and then cloned into pET21a plasmid, ...

  4. Cysteine and hydrogen sulfide in the regulation of metabolism:Insights from genetics and pharmacology

    OpenAIRE

    Carter, Roderick N; Morton, Nicholas M

    2016-01-01

    Abstract Obesity and diabetes represent a significant and escalating worldwide health burden. These conditions are characterized by abnormal nutrient homeostasis. One such perturbation is altered metabolism of the sulphur?containing amino acid cysteine. Obesity is associated with elevated plasma cysteine, whereas diabetes is associated with reduced cysteine levels. One mechanism by which cysteine may act is through its enzymatic breakdown to produce hydrogen sulphide (H2S), a gasotransmitter ...

  5. On the sintering behaviour of steel bonded TiC-Cr3C2 and TiC-Cr3C2-WC mixed carbides

    International Nuclear Information System (INIS)

    Stojanov, L.G.; Exner, H.E.

    1978-01-01

    Powder mixtures of TiC+Cr 3 C 2 and TiC+Cr 3 C 2 + WC were hot pressed to nearly full density. The lattice parameter of the resulting cubic mixed crystal decreases linearly with increasing additions of Cr 3 C 2 and (Cr 3 C 2 +WC 1:1). Microhardness increases with Cr 3 C 2 content up to 20 wt.%. By addition of WC, microhardness is increased further and reaches a maximum value of approx. 38 000 MN/m 2 for 20 wt.% Cr 3 C 2 and 20 wt.% WC. From these solid solutions powder compositions of Ferro-TiC type were produced by milling with 55 wt.% Fe and 0.4 wt.% C. The sintering behaviour of these powders was studied in a vacuum dilatometer. The pronounced increase of shrinkage by Cr 3 C 2 and higher amounts of Cr 3 C 2 +WC dissolved in TiC previous to binder phase melting is attributed to the increased solubility of the carbide in solid iron. Presintering at 700 0 C in hydrogen has a negative influence on sintering activity and requires much higher temperatures for complete densification during subsequent vacuum sintering. (orig.) [de

  6. HI absorption in 3C 49 and 3C 268.3 - Probing the environment of compact steep spectrum and GHz peaked spectrum sources

    NARCIS (Netherlands)

    Labiano, A; Vermeulen, RC; Barthel, PD; O'Dea, CP; Gallimore, JF; Baum, S; de Vries, W

    Aims. Localize and study the redshifted 21 cm H I absorption known to occur in the subgalactic sized compact steep spectrum galaxies 3C 49 and 3C 268.3. Methods. We carried out European VLBI Network UHF hand spectral line observations. Results. We have detected H I absorption towards the western

  7. 17 CFR 270.3c-3 - Definition of certain terms used in section 3(c)(1) of the Act with respect to certain debt...

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Definition of certain terms used in section 3(c)(1) of the Act with respect to certain debt securities offered by small business... COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.3c-3 Definition of certain...

  8. Synthesis and biological evaluation of branched and conformationally restricted analogs of the anticancer compounds 3'-C-ethynyluridine (EUrd) and 3'-C-ethynylcytidine (ECyd)

    DEFF Research Database (Denmark)

    Hrdlicka, Patrick J; Andersen, Nicolai K; Jepsen, Jan S

    2005-01-01

    The synthesis of branched and conformationally restricted analogs of the anticancer nucleosides 3'-C-ethynyluridine (EUrd) and 3'-C-ethynylcytidine (ECyd) is presented. Molecular modeling and (1)H NMR coupling constant analysis revealed that the furanose rings of all analogs except the LNA analog...

  9. Mutagenicity and cytotoxicity of two regioisomeric mercapturic acids and cysteine S-conjugates of trichloroethylene.

    NARCIS (Netherlands)

    Commandeur, J.N.M.; Boogaard, P.J.; Mulder, G.J.; Vermeulen, N.P.E.

    1991-01-01

    The mutagenicity, cytotoxicity and metabolism of two regioisomic l-cysteine- and N-acetyl-l-cysteine-S-conjugates of trichloroethylene were studied. The 1,2-dichlorovinyl(1,2-DCV) isomers of both the cysteine conjugate and the mercapturate were much stronger mutagens in the Ames test with Salmonella

  10. Effects of cysteine on growth, protease production, and catalase activity of Pseudomonas fluorescens.

    OpenAIRE

    Himelbloom, B H; Hassan, H M

    1986-01-01

    Cysteine inhibits growth of and protease production by Pseudomonas fluorescens NC3. Catalase activity in P. fluorescens NC3 was increased by cysteine. The addition of exogenous hydrogen peroxide did not increase catalase activity, thus suggesting a role for the endogenous generation of hydrogen peroxide via the autoxidation of cysteine.

  11. 18 CFR 3c.3 - Reporting fraud, waste, abuse, and corruption and cooperation with official inquiries.

    Science.gov (United States)

    2010-04-01

    ..., abuse, and corruption and cooperation with official inquiries. 3c.3 Section 3c.3 Conservation of Power... OF CONDUCT § 3c.3 Reporting fraud, waste, abuse, and corruption and cooperation with official..., abuse, and corruption in Commission programs, including on the part of Commission employees, contractors...

  12. 17 CFR 270.3c-2 - Definition of beneficial ownership in small business investment companies.

    Science.gov (United States)

    2010-04-01

    ... 1940 § 270.3c-2 Definition of beneficial ownership in small business investment companies. For the... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Definition of beneficial ownership in small business investment companies. 270.3c-2 Section 270.3c-2 Commodity and Securities...

  13. Barley (Hordeum vulgare L.) cysteine proteases: heterologous expression, purification and characterization

    DEFF Research Database (Denmark)

    Rosenkilde, Anne Lind; Dionisio, Giuseppe; Holm, Preben Bach

    2011-01-01

    During germination of barley seeds, mobilization of protein is essential and cysteine proteases accounts for more than 90 % of the total proteolytic activity in the degradation of barley seed storage proteins. Cysteine proteases exist as pro-enzyme and is activated through reduction of the active...... site cysteines and by removal of the pro-domain. The complement of cysteine proteases is comprehensive and for detailed studies of the individual components of this complement, a fast and efficient eukaryotic expression platform is highly desirable. A cDNA clone of the barley key cysteine endoprotease...

  14. Electrostatics of cysteine residues in proteins: Parameterization and validation of a simple model

    Science.gov (United States)

    Salsbury, Freddie R.; Poole, Leslie B.; Fetrow, Jacquelyn S.

    2013-01-01

    One of the most popular and simple models for the calculation of pKas from a protein structure is the semi-macroscopic electrostatic model MEAD. This model requires empirical parameters for each residue to calculate pKas. Analysis of current, widely used empirical parameters for cysteine residues showed that they did not reproduce expected cysteine pKas; thus, we set out to identify parameters consistent with the CHARMM27 force field that capture both the behavior of typical cysteines in proteins and the behavior of cysteines which have perturbed pKas. The new parameters were validated in three ways: (1) calculation across a large set of typical cysteines in proteins (where the calculations are expected to reproduce expected ensemble behavior); (2) calculation across a set of perturbed cysteines in proteins (where the calculations are expected to reproduce the shifted ensemble behavior); and (3) comparison to experimentally determined pKa values (where the calculation should reproduce the pKa within experimental error). Both the general behavior of cysteines in proteins and the perturbed pKa in some proteins can be predicted reasonably well using the newly determined empirical parameters within the MEAD model for protein electrostatics. This study provides the first general analysis of the electrostatics of cysteines in proteins, with specific attention paid to capturing both the behavior of typical cysteines in a protein and the behavior of cysteines whose pKa should be shifted, and validation of force field parameters for cysteine residues. PMID:22777874

  15. Fluoresence quenching of riboflavin in aqueous solution by methionin and cystein

    International Nuclear Information System (INIS)

    Droessler, P.; Holzer, W.; Penzkofer, A.; Hegemann, P.

    2003-01-01

    The fluorescence quantum distributions, fluorescence quantum yields, and fluorescence lifetimes of riboflavin in methanol, DMSO, water, and aqueous solutions of the sulphur atom containing amino acids methionin and cystein have been determined. In methanol, DMSO, and water (pH=4-8) only dynamic fluorescence reduction due to intersystem crossing and internal conversion is observed. In aqueous methionin solutions of pH=5.25-9 a pH independent static and dynamic fluorescence quenching occurs probably due to riboflavin anion-methionin cation pair formation. In aqueous cystein solutions (pH range from 4.15 to 9) the fluorescence quenching increases with rising pH due to cystein thiolate formation. The cystein thiol form present at low pH does not react with neutral riboflavin. Cystein thiolate present at high pH seems to react with neutral riboflavin causing riboflavin deprotonation (anion formation) by cystein thiolate reduction to the cystein thiol form

  16. Identification, classification and expression pattern analysis of sugarcane cysteine proteinases

    Directory of Open Access Journals (Sweden)

    Gustavo Coelho Correa

    2001-12-01

    Full Text Available Cysteine proteases are peptidyl hydrolyses dependent on a cysteine residue at the active center. The physical and chemical properties of cysteine proteases have been extensively characterized, but their precise biological functions have not yet been completely understood, although it is known that they are involved in a number of events such as protein turnover, cancer, germination, programmed cell death and senescence. Protein sequences from different cysteine proteinases, classified as members of the E.C.3.4.22 sub-sub-class, were used to perform a T-BLAST-n search on the Brazilian Sugarcane Expressed Sequence Tags project (SUCEST data bank. Sequence homology was found with 76 cluster sequences that corresponded to possible cysteine proteinases. The alignments of these SUCEST clusters with the sequence of cysteine proteinases of known origins provided important information about the classification and possible function of these sugarcane enzymes. Inferences about the expression pattern of each gene were made by direct correlation with the SUCEST cDNA libraries from which each cluster was derived. Since no previous reports of sugarcane cysteine proteinases genes exists, this study represents a first step in the study of new biochemical, physiological and biotechnological aspects of sugarcane cysteine proteases.Proteinases cisteínicas são peptidil-hidrolases dependentes de um resíduo de cisteína em seu sítio ativo. As propriedades físico-químicas destas proteinases têm sido amplamente caracterizadas, entretanto suas funções biológicas ainda não foram completamente elucidadas. Elas estão envolvidas em um grande número de eventos, tais como: processamento e degradação protéica, câncer, germinação, morte celular programada e processos de senescência. Diferentes proteinases cisteínicas, classificadas pelo Comitê de Nomenclatura da União Internacional de Bioquímica e Biologia Molecular (IUBMB como pertencentes à sub

  17. Divergent unprotected peptide macrocyclisation by palladium-mediated cysteine arylation.

    Science.gov (United States)

    Rojas, Anthony J; Zhang, Chi; Vinogradova, Ekaterina V; Buchwald, Nathan H; Reilly, John; Pentelute, Bradley L; Buchwald, Stephen L

    2017-06-01

    Macrocyclic peptides are important therapeutic candidates due to their improved physicochemical properties in comparison to their linear counterparts. Here we detail a method for a divergent macrocyclisation of unprotected peptides by crosslinking two cysteine residues with bis-palladium organometallic reagents. These synthetic intermediates are prepared in a single step from commercially available aryl bis-halides. Two bioactive linear peptides with cysteine residues at i , i + 4 and i , i + 7 positions, respectively, were cyclised to introduce a diverse array of aryl and bi-aryl linkers. These two series of macrocyclic peptides displayed similar linker-dependent lipophilicity, phospholipid affinity, and unique volume of distributions. Additionally, one of the bioactive peptides showed target binding affinity that was predominantly affected by the length of the linker. Collectively, this divergent strategy allowed rapid and convenient access to various aryl linkers, enabling the systematic evaluation of the effect of appending unit on the medicinal properties of macrocyclic peptides.

  18. Carbon Nanotubes Facilitate Oxidation of Cysteine Residues of Proteins.

    Science.gov (United States)

    Hirano, Atsushi; Kameda, Tomoshi; Wada, Momoyo; Tanaka, Takeshi; Kataura, Hiromichi

    2017-10-19

    The adsorption of proteins onto nanoparticles such as carbon nanotubes (CNTs) governs the early stages of nanoparticle uptake into biological systems. Previous studies regarding these adsorption processes have primarily focused on the physical interactions between proteins and nanoparticles. In this study, using reduced lysozyme and intact human serum albumin in aqueous solutions, we demonstrated that CNTs interact chemically with proteins. The CNTs induce the oxidation of cysteine residues of the proteins, which is accounted for by charge transfer from the sulfhydryl groups of the cysteine residues to the CNTs. The redox reaction simultaneously suppresses the intermolecular association of proteins via disulfide bonds. These results suggest that CNTs can affect the folding and oxidation degree of proteins in biological systems such as blood and cytosol.

  19. Creating and facilitating change for Person-Centred Coordinated Care (P3C): The development of the Organisational Change Tool (P3C-OCT).

    Science.gov (United States)

    Horrell, Jane; Lloyd, Helen; Sugavanam, Thavapriya; Close, James; Byng, Richard

    2018-04-01

    Person Centred Coordinated Care (P3C) is a UK priority for patients, carers, professionals, commissioners and policy makers. Services are developing a range of approaches to deliver this care with a lack of tools to guide implementation. A scoping review and critical examination of current policy, key literature and NHS guidelines, together with stakeholder involvement led to the identification of domains, subdomains and component activities (processes and behaviours) required to deliver P3C. These were validated through codesign with stakeholders via a series of workshops and cognitive interviews. Six core domains of P3C were identified as follows: (i) my goals, (ii) care planning, (iii) transitions, (iv) decision making (v), information and communication and (vi) organizational support activities. These were populated by 29 core subdomains (question items). A number of response codes (components) to each question provide examples of the processes and activities that can be actioned to achieve each core subdomain of P3C. The P3C-OCT provides a coherent approach to monitoring progress and supporting practice development towards P3C. It can be used to generate a shared understanding of the core domains of P3C at a service delivery level, and support reorganization of care for those with complex needs. The tool can reliably detect change over time, as demonstrated in a sample of 40 UK general practices. It is currently being used in four UK evaluations of new models of care and being further developed as a training tool for the delivery of P3C. © 2017 The Authors Health Expectations Published by John Wiley & Sons Ltd.

  20. Subcellular distribution of glutathione and cysteine in cyanobacteria

    OpenAIRE

    Zechmann, Bernd; Tomašić, Ana; Horvat, Lucija; Fulgosi, Hrvoje

    2010-01-01

    Glutathione plays numerous important functions in eukaryotic and prokaryotic cells. Whereas it can be found in virtually all eukaryotic cells, its production in prokaryotes is restricted to cyanobacteria and proteobacteria and a few strains of gram-positive bacteria. In bacteria, it is involved in the protection against reactive oxygen species (ROS), osmotic shock, acidic conditions, toxic chemicals, and heavy metals. Glutathione synthesis in bacteria takes place in two steps out of cysteine,...

  1. Allicin and derivates are cysteine protease inhibitors with antiparasitic activity.

    Science.gov (United States)

    Waag, Thilo; Gelhaus, Christoph; Rath, Jennifer; Stich, August; Leippe, Matthias; Schirmeister, Tanja

    2010-09-15

    Allicin and derivatives thereof inhibit the CAC1 cysteine proteases falcipain 2, rhodesain, cathepsin B and L in the low micromolar range. The structure-activity relationship revealed that only derivatives with primary carbon atom in vicinity to the thiosulfinate sulfur atom attacked by the active-site Cys residue are active against the target enzymes. Some compounds also show potent antiparasitic activity against Plasmodium falciparum and Trypanosoma brucei brucei. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  2. Effect of cysteine supplementation on in vitro maturation of bovine ...

    African Journals Online (AJOL)

    B Rahim, S Jalal, N Yosef ... Cumulus-oocyte complexes (COCs) from abattoir ovaries were matured in vitro in Hepes-TCM 199 supplemented with 0.2 mM sodium pyruvate, 1 μg/ml 17-β-estradiol, 10% fetal calf serum (FCS), 0.5 μg/ml bFSH and 0 (control) and 100 or 500 μM/ml of cysteine for 24 h. When COCs matured in ...

  3. Acid-Mediated Tumor Proteolysis: Contribution of Cysteine Cathepsins

    Directory of Open Access Journals (Sweden)

    Jennifer M Rothberg

    2013-10-01

    Full Text Available One of the noncellular microenvironmental factors that contribute to malignancy of solid tumors is acidic peritumoral pH. We have previously demonstrated that extracellular acidosis leads to localization of the cysteine pro-tease cathepsin B on the tumor cell membrane and its secretion. The objective of the present study was to determine if an acidic extracellular pH such as that observed in vivo (i.e., pHe 6.8 affects the activity of proteases, e.g., cathepsin B, that contribute to degradation of collagen IV by tumor cells when grown in biologically relevant three-dimensional (3D cultures. For these studies, we used 1 3D reconstituted basement membrane overlay cultures of human carcinomas, 2 live cell imaging assays to assess proteolysis, and 3 in vivo imaging of active tumor proteases. At pHe 6.8, there were increases in pericellular active cysteine cathepsins and in degradation of dye-quenched collagen IV, which was partially blocked by a cathepsin B inhibitor. Imaging probes for active cysteine cathepsins localized to tumors in vivo. The amount of bound probe decreased in tumors in bicarbonate-treated mice, a treatment previously shown to increase peritumoral pHe and reduce local invasion of the tumors. Our results are consistent with the acid-mediated invasion hypothesis and with a role for cathepsin B in promoting degradation of a basement membrane protein substrate, i.e., type IV collagen, in an acidic peritumoral environment.

  4. The effect of cysteine on electrodeposition of gold nanoparticle

    International Nuclear Information System (INIS)

    Dolati, A.; Imanieh, I.; Salehi, F.; Farahani, M.

    2011-01-01

    Highlights: → Cysteine was found as an appropriate additive for electrodeposition of gold nanoparticles. → The deposition mechanism of gold nanoparticle was determined as instantaneous nucleation. → Oxygen reduction on the gold nanoparticle surface was eight times greater than that on the conventional gold deposits. - Abstract: The most applications of gold nanoparticles are in the photo-electronical accessories and bio-chemical sensors. Chloride solution with cysteine additive was used as electrolyte in gold nanoparticles electrodeposition. The nucleation and growing mechanism were studied by electrochemical techniques such as cyclic voltammetry and chronoamperometry, in order to obtain a suitable nano structure. The deposition mechanism was determined as instantaneous nucleation and the dimension of particles was controlled in nanometric particle size range. Atomic Force Microscope was used to evaluate the effect of cysteine on the morphology and topography of gold nanoparticles. Finally the catalytic property of gold nanoparticle electrodeposited was studied in KOH solution, where oxygen reduction on the gold nanoparticle surface was eight times greater than that on the conventional gold deposits.

  5. The axonal guidance cue semaphorin 3C contributes to alveolar growth and repair.

    Directory of Open Access Journals (Sweden)

    Arul Vadivel

    Full Text Available Lung diseases characterized by alveolar damage such as bronchopulmonary dysplasia (BPD in premature infants and emphysema lack efficient treatments. Understanding the mechanisms contributing to normal and impaired alveolar growth and repair may identify new therapeutic targets for these lung diseases. Axonal guidance cues are molecules that guide the outgrowth of axons. Amongst these axonal guidance cues, members of the Semaphorin family, in particular Semaphorin 3C (Sema3C, contribute to early lung branching morphogenesis. The role of Sema3C during alveolar growth and repair is unknown. We hypothesized that Sema3C promotes alveolar development and repair. In vivo Sema3C knock down using intranasal siRNA during the postnatal stage of alveolar development in rats caused significant air space enlargement reminiscent of BPD. Sema3C knock down was associated with increased TLR3 expression and lung inflammatory cells influx. In a model of O2-induced arrested alveolar growth in newborn rats mimicking BPD, air space enlargement was associated with decreased lung Sema3C mRNA expression. In vitro, Sema3C treatment preserved alveolar epithelial cell viability in hyperoxia and accelerated alveolar epithelial cell wound healing. Sema3C preserved lung microvascular endothelial cell vascular network formation in vitro under hyperoxic conditions. In vivo, Sema3C treatment of hyperoxic rats decreased lung neutrophil influx and preserved alveolar and lung vascular growth. Sema3C also preserved lung plexinA2 and Sema3C expression, alveolar epithelial cell proliferation and decreased lung apoptosis. In conclusion, the axonal guidance cue Sema3C promotes normal alveolar growth and may be worthwhile further investigating as a potential therapeutic target for lung repair.

  6. The IRC7 gene encodes cysteine desulphydrase activity and confers on yeast the ability to grow on cysteine as a nitrogen source.

    Science.gov (United States)

    Santiago, Margarita; Gardner, Richard C

    2015-07-01

    Although cysteine desulphydrase activity has been purified and characterized from Saccharomyces cerevisiae, the gene encoding this activity in vivo has never been defined. We show that the full-length IRC7 gene, encoded by the YFR055W open reading frame, encodes a protein with cysteine desulphydrase activity. Irc7p purified to homogeneity is able to utilize l-cysteine as a substrate, producing pyruvate and hydrogen sulphide as products of the reaction. Purified Irc7p also utilized l-cystine and some other cysteine conjugates, but not l-cystathionine or l-methionine, as substrates. We further show that, in vivo, the IRC7 gene is both necessary and sufficient for yeast to grow on l-cysteine as a nitrogen source, and that overexpression of the gene results in increased H2 S production. Strains overexpressing IRC7 are also hypersensitive to a toxic analogue, S-ethyl-l-cysteine. While IRC7 has been identified as playing a critical role in converting cysteine conjugates to volatile thiols that are important in wine aroma, its biological role in yeast cells is likely to involve regulation of cysteine and redox homeostasis. Copyright © 2015 John Wiley & Sons, Ltd.

  7. Structure and mechanism leading to formation of the cysteine sulfinate product complex of a biomimetic cysteine dioxygenase model.

    Science.gov (United States)

    Sallmann, Madleen; Kumar, Suresh; Chernev, Petko; Nehrkorn, Joscha; Schnegg, Alexander; Kumar, Devesh; Dau, Holger; Limberg, Christian; de Visser, Sam P

    2015-05-11

    Cysteine dioxygenase is a unique nonheme iron enzyme that is involved in the metabolism of cysteine in the body. It contains an iron active site with an unusual 3-His ligation to the protein, which contrasts with the structural features of common nonheme iron dioxygenases. Recently, some of us reported a truly biomimetic model for this enzyme, namely a trispyrazolylborato iron(II) cysteinato complex, which not only has a structure very similar to the enzyme-substrate complex but also represents a functional model: Treatment of the model with dioxygen leads to cysteine dioxygenation, as shown by isolating the cysteine part of the product in the course of the work-up. However, little is known on the conversion mechanism and, so far, not even the structure of the actual product complex had been characterised, which is also unknown in case of the enzyme. In a multidisciplinary approach including density functional theory calculations and X-ray absorption spectroscopy, we have now determined the structure of the actual sulfinato complex for the first time. The Cys-SO2 (-) functional group was found to be bound in an η(2) -O,O-coordination mode, which, based on the excellent resemblance between model and enzyme, also provides the first support for a corresponding binding mode within the enzymatic product complex. Indeed, this is again confirmed by theory, which had predicted a η(2) -O,O-binding mode for synthetic as well as the natural enzyme. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Identification of novel malarial cysteine protease inhibitors using structure-based virtual screening of a focused cysteine protease inhibitor library.

    Science.gov (United States)

    Shah, Falgun; Mukherjee, Prasenjit; Gut, Jiri; Legac, Jennifer; Rosenthal, Philip J; Tekwani, Babu L; Avery, Mitchell A

    2011-04-25

    Malaria, in particular that caused by Plasmodium falciparum , is prevalent across the tropics, and its medicinal control is limited by widespread drug resistance. Cysteine proteases of P. falciparum , falcipain-2 (FP-2) and falcipain-3 (FP-3), are major hemoglobinases, validated as potential antimalarial drug targets. Structure-based virtual screening of a focused cysteine protease inhibitor library built with soft rather than hard electrophiles was performed against an X-ray crystal structure of FP-2 using the Glide docking program. An enrichment study was performed to select a suitable scoring function and to retrieve potential candidates against FP-2 from a large chemical database. Biological evaluation of 50 selected compounds identified 21 diverse nonpeptidic inhibitors of FP-2 with a hit rate of 42%. Atomic Fukui indices were used to predict the most electrophilic center and its electrophilicity in the identified hits. Comparison of predicted electrophilicity of electrophiles in identified hits with those in known irreversible inhibitors suggested the soft-nature of electrophiles in the selected target compounds. The present study highlights the importance of focused libraries and enrichment studies in structure-based virtual screening. In addition, few compounds were screened against homologous human cysteine proteases for selectivity analysis. Further evaluation of structure-activity relationships around these nonpeptidic scaffolds could help in the development of selective leads for antimalarial chemotherapy.

  9. Doping and stability of 3C-SiC: from thinfilm to bulk growth

    DEFF Research Database (Denmark)

    Jokubavicius, V.; Sun, J.; Linnarsson, M. K.

    cell technology. Nitrogen and boron doped 3C-SiC layers can depict a new infrared LED. Hexagonal SiC is an excellent substrate for heteropeitaxial growth of 3C-SiC due to excellent compatibility in lattice constant and thermal expansion coefficient. However, the growth of 3C-SiC on such substrates......-SiC for optoelectronic applications are discussed....

  10. A novel potentiometric biosensor for selective L-cysteine determination using L-cysteine-desulfhydrase producing Trichosporon jirovecii yeast cells coupled with sulfide electrode

    International Nuclear Information System (INIS)

    Hassan, Saad S.M.; El-Baz, Ashraf F.; Abd-Rabboh, Hisham S.M.

    2007-01-01

    Trichosporon jirovecii yeast cells are used for the first time as a source of L-cysteine desulfhydrase enzyme (EC 4.4.1.1) and incorporated in a biosensor for determining L-cysteine. The cells are grown under cadmium stress conditions to increase the expression level of the enzyme. The intact cells are immobilized on the membrane of a solid-state Ag 2 S electrode to provide a simple L-cysteine responsive biosensor. Upon immersion of the sensor in L-cysteine containing solutions, L-cysteine undergoes enzymatic hydrolysis into pyruvate, ammonia and sulfide ion. The rate of sulfide ion formation is potentiometrically measured as a function of L-cysteine concentration. Under optimized conditions (phosphate buffer pH 7, temperature 37 ± 1 deg. C and actual weight of immobilized yeast cells 100 mg), a linear relationship between L-cysteine concentration and the initial rate of sulfide liberation (dE/dt) is obtained. The sensor response covers the concentration range of 0.2-150 mg L -1 (1.7-1250 μmol L -1 ) L-cysteine. Validation of the assay method according to the quality control/quality assurance standards (precision, accuracy, between-day variability, within-day reproducibility, range of measurements and lower limit of detection) reveals remarkable performance characteristics of the proposed biosensor. The sensor is satisfactorily utilized for determination of L-cysteine in some pharmaceutical formulations. The lower limit of detection is ∼1 μmol L -1 and the accuracy and precision of the method are 97.5% and ±1.1%, respectively. Structurally similar sulfur containing compounds such as glutathione, cystine, methionine, and D-cysteine do no interfere

  11. Generation of a C3c specific monoclonal antibody and assessment of C3c as a putative inflammatory marker derived from complement factor C3

    DEFF Research Database (Denmark)

    Palarasah, Yaseelan; Skjodt, Karsten; Brandt, Jette

    2010-01-01

    complex (C5b-C9) and quantification of complement split products by precipitation-in-gel techniques (e.g. C3d). We have developed a mouse monoclonal antibody (mAb) that is able to detect fluid phase C3c without interference from other products generated from the complement component C3. The C3c specific m....... The C3c mAb was confirmed to be C3c specific, as it showed no cross-reactivity with native (un-cleaved) C3, with C3b, iC3b, or with C3d. Also, no significant reaction was observed with C3 fragments in factor I deficient sera or plasma. This antibody forms the basis for the generation of a robust ELISA...... that allows for a quick and reliable evaluation of complement activation and consumption as a marker for inflammatory processes. We established the C3c plasma range in 100 healthy Danish blood donors with a mean of 3.47 μg/ml and a range of 2.12-4.92 μg/ml. We believe that such an antibody might...

  12. Enhancement of thioredoxin/glutaredoxin-mediated L-cysteine synthesis from S-sulfocysteine increases L-cysteine production in Escherichia coli

    Science.gov (United States)

    2012-01-01

    Background Escherichia coli has two L-cysteine biosynthetic pathways; one is synthesized from O-acetyl L-serine (OAS) and sulfate by L-cysteine synthase (CysK), and another is produced via S-sulfocysteine (SSC) from OAS and thiosulfate by SSC synthase (CysM). SSC is converted into L-cysteine and sulfite by an uncharacterized reaction. As thioredoxins (Trx1 and Trx2) and glutaredoxins (Grx1, Grx2, Grx3, Grx4, and NrdH) are known as reductases of peptidyl disulfides, overexpression of such reductases might be a good way for improving L-cysteine production to accelerate the reduction of SSC in E. coli. Results Because the redox enzymes can reduce the disulfide that forms on proteins, we first tested whether these enzymes catalyze the reduction of SSC to L-cysteine. All His-tagged recombinant enzymes, except for Grx4, efficiently convert SSC into L-cysteine in vitro. Overexpression of Grx1 and NrdH enhanced a 15-40% increase in the E. coliL-cysteine production. On the other hand, disruption of the cysM gene cancelled the effect caused by the overexpression of Grx1 and NrdH, suggesting that its improvement was due to the efficient reduction of SSC under the fermentative conditions. Moreover, L-cysteine production in knockout mutants of the sulfite reductase genes (ΔcysI and ΔcysJ) and the L-cysteine synthase gene (ΔcysK) each decreased to about 50% of that in the wild-type strain. Interestingly, there was no significant difference in L-cysteine production between wild-type strain and gene deletion mutant of the upstream pathway of sulfite (ΔcysC or ΔcysH). These results indicate that sulfite generated from the SSC reduction is available as the sulfur source to produce additional L-cysteine molecule. It was finally found that in the E. coliL-cysteine producer that co-overexpress glutaredoxin (NrdH), sulfite reductase (CysI), and L-cysteine synthase (CysK), there was the highest amount of L-cysteine produced per cell. Conclusions In this work, we showed that Grx1 and

  13. Activated human CD4 T cells express transporters for both cysteine and cystine

    DEFF Research Database (Denmark)

    Levring, Trine Bøegh; Hansen, Ann Kathrine; Nielsen, Bodil Lisbeth

    2012-01-01

    Because naïve T cells are unable to import cystine due to the absence of cystine transporters, it has been suggested that T cell activation is dependent on cysteine generated by antigen presenting cells. The aim of this study was to determine at which phases during T cell activation exogenous...... cystine/cysteine is required and how T cells meet this requirement. We found that early activation of T cells is independent of exogenous cystine/cysteine, whereas T cell proliferation is strictly dependent of uptake of exogenous cystine/cysteine. Naïve T cells express no or very low levels of both...... cystine and cysteine transporters. However, we found that these transporters become strongly up-regulated during T cell activation and provide activated T cells with the required amount of cystine/cysteine needed for T cell proliferation. Thus, T cells are equipped with mechanisms that allow T cell...

  14. 17 CFR 270.3c-5 - Beneficial ownership by knowledgeable employees and certain other persons.

    Science.gov (United States)

    2010-04-01

    ... Company. For purposes of this definition, the term “investment company” as used in section 2(a)(3) of the Act includes a Covered Company. (2) The term Covered Company means a Section 3(c)(1) Company or a... SECURITIES AND EXCHANGE COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.3c...

  15. Sintering behaviour and mechanical properties of Cr3C2–NiCr ...

    Indian Academy of Sciences (India)

    fracture toughness. Keywords. Cermet; Cr3C2–NiCr; sintering; mechanical properties. ... et al investigated the mechanical properties of VC, Cr3C2 and NbC doped ..... Huang S G, Li L, Van der Biest O and Vleugels J 2008 J. Alloys. Compds.

  16. Cysteine Supplementation May be Beneficial in a Subgroup of Mitochondrial Translation Deficiencies.

    Science.gov (United States)

    Bartsakoulia, Marina; Mϋller, Juliane S; Gomez-Duran, Aurora; Yu-Wai-Man, Patrick; Boczonadi, Veronika; Horvath, Rita

    2016-08-30

    Mitochondrial encephalomyopathies are severe, relentlessly progressive conditions and there are very few effective therapies available to date. We have previously suggested that in two rare forms of reversible mitochondrial disease (reversible infantile respiratory chain deficiency and reversible infantile hepatopathy) supplementation with L-cysteine can improve mitochondrial protein synthesis, since cysteine is required for the 2-thiomodification of mitochondrial tRNAs. We studied whether supplementation with L-cysteine or N-acetyl-cysteine (NAC) results in any improvement of the mitochondrial function in vitro in fibroblasts of patients with different genetic forms of abnormal mitochondrial translation. We studied in vitro in fibroblasts of patients carrying the common m.3243A>G and m.8344A>G mutations or autosomal recessive mutations in genes affecting mitochondrial translation, whether L-cysteine or N-acetyl-cysteine supplementation have an effect on mitochondrial respiratory chain function. Here we show that supplementation with L-cysteine, but not with N-acetyl-cysteine partially rescues the mitochondrial translation defect in vitro in fibroblasts of patients carrying the m.3243A>G and m.8344A>G mutations. In contrast, N-acetyl-cysteine had a beneficial effect on mitochondrial translation in TRMU and MTO1 deficient fibroblasts. Our results suggest that L-cysteine or N-acetyl-cysteine supplementation may be a potential treatment for selected subgroups of patients with mitochondrial translation deficiencies. Further studies are needed to explore the full potential of cysteine supplementation as a treatment for patients with mitochondrial disease.

  17. Enhancement of L-cysteine production by disruption of yciW in Escherichia coli.

    Science.gov (United States)

    Kawano, Yusuke; Ohtsu, Iwao; Takumi, Kazuhiro; Tamakoshi, Ai; Nonaka, Gen; Funahashi, Eri; Ihara, Masaki; Takagi, Hiroshi

    2015-02-01

    Using in silico analysis, the yciW gene of Escherichia coli was identified as a novel L-cysteine regulon that may be regulated by the transcriptional activator CysB for sulfur metabolic genes. We found that overexpression of yciW conferred tolerance to L-cysteine, but disruption of yciW increased L-cysteine production in E. coli. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  18. Effects of cysteine protease inhibitors on rabbit cathepsin D maturation

    International Nuclear Information System (INIS)

    Samarel, A.M.; Ferguson, A.G.; Decker, R.S.; Lesch, M.

    1989-01-01

    To examine the effects of cysteine protease inhibitors on cathepsin D intracellular transport, proteolytic processing, and secretion, primary cultures of rabbit cardiac fibroblasts were grown to confluence and exposed to media containing leupeptin, E 64, or chloroquine. Cathepsin D maturation was then evaluated in pulse-chase biosynthetic labeling experiments. None of the three agents affected the charge modification of procathepsin D within the Golgi apparatus. However, all three agents interfered with the subsequent proteolytic processing of procathepsin D isoforms to active cathepsin D. Both leupeptin and E 64 caused the intracellular accumulation of large amounts of a Mr 51,000 processing intermediate. Trace amounts of this intermediate were also detected in chloroquine-treated cells. Combined activity assay and radioimmunoassay of cell lysates indicated that this partially processed form of cathepsin D possessed proteolytic activity. Whereas low medium concentrations of leupeptin (10-100 microM) but not E 64 appeared to stimulate procathepsin D secretion, neither agent appeared to have a major effect on the rate of proenzyme secretion at doses required to inhibit proteolytic maturation (1-10 mM). Furthermore, pretreatment of cells with 10 mM leupeptin appeared only to delay, but not prevent, the intracellular transport of cathepsin D to lysosomes. In contrast, chloroquine increased procathepsin D secretion in a dose-dependent manner, diverting the majority of newly synthesized procathepsin D from the intracellular protease(s) responsible for proteolytic processing. These results suggest that cysteine proteases participate in the proteolytic maturation of procathepsin D during the transport of newly synthesized enzyme to lysosomes, but cysteine protease-mediated proteolytic processing is not required for cathepsin D activation or lysosomal translocation

  19. Effect of L-cysteine on the oxidation of cyclohexane catalyzed by manganeseporphyrin.

    Science.gov (United States)

    Zhou, Wei-You; Tian, Peng; Chen, Yong; He, Ming-Yang; Chen, Qun; Chen, Zai Xin

    2015-06-01

    Effect of L-cysteine as the cocatalyst on the oxidation of cyclohexane by tert-butylhydroperoxide (TBHP) catalyzed by manganese tetraphenylporphyrin (MnTPP) has been investigated. The results showed that L-cysteine could moderately improve the catalytic activity of MnTPP and significantly increase the selectivity of cyclohexanol. Different from imidazole and pyridine, the L-cysteine may perform dual roles in the catalytic oxidation of cyclohexane. Besides as the axial ligand for MnTPP, the L-cysteine could also react with cyclohexyl peroxide formed as the intermediate to produce alcohol as the main product. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. L-cysteine suppresses ghrelin and reduces appetite in rodents and humans.

    Science.gov (United States)

    McGavigan, A K; O'Hara, H C; Amin, A; Kinsey-Jones, J; Spreckley, E; Alamshah, A; Agahi, A; Banks, K; France, R; Hyberg, G; Wong, C; Bewick, G A; Gardiner, J V; Lehmann, A; Martin, N M; Ghatei, M A; Bloom, S R; Murphy, K G

    2015-03-01

    High-protein diets promote weight loss and subsequent weight maintenance, but are difficult to adhere to. The mechanisms by which protein exerts these effects remain unclear. However, the amino acids produced by protein digestion may have a role in driving protein-induced satiety. We tested the effects of a range of amino acids on food intake in rodents and identified l-cysteine as the most anorexigenic. Using rodents we further studied the effect of l-cysteine on food intake, behaviour and energy expenditure. We proceeded to investigate its effect on neuronal activation in the hypothalamus and brainstem before investigating its effect on gastric emptying and gut hormone release. The effect of l-cysteine on appetite scores and gut hormone release was then investigated in humans. l-Cysteine dose-dependently decreased food intake in both rats and mice following oral gavage and intraperitoneal administration. This effect did not appear to be secondary to behavioural or aversive side effects. l-Cysteine increased neuronal activation in the area postrema and delayed gastric emptying. It suppressed plasma acyl ghrelin levels and did not reduce food intake in transgenic ghrelin-overexpressing mice. Repeated l-cysteine administration decreased food intake in rats and obese mice. l-Cysteine reduced hunger and plasma acyl ghrelin levels in humans. Further work is required to determine the chronic effect of l-cysteine in rodents and humans on appetite and body weight, and whether l-cysteine contributes towards protein-induced satiety.

  1. Synthesis and Electrochemical Properties of Two-Dimensional RGO/Ti3C2Tx Nanocomposites

    Directory of Open Access Journals (Sweden)

    Changjie Shen

    2018-01-01

    Full Text Available MXene is a new type of two-dimensional layered material. Herein, a GO/Ti3C2Tx nanocomposite was prepared by a simple liquid phase method, and the obtained GO/Ti3C2Tx was transformed into RGO/Ti3C2Tx under high temperature with Ar/H2. The prepared samples were characterized using X-ray diffraction (XRD, Raman measurement, scanning electron microscopy (SEM, energy disperse spectroscopy (EDS, and X-ray photoelectron spectroscopy (XPS. As an electrode material in lithium-ion batteries, the RGO/Ti3C2Tx nanocomposite exhibited an excellent electrochemical performance and an excellent rate performance. Compared to pure Ti3C2Tx, the nanocomposite had a better reversible capacity at different current densities and had no attenuation after 200 cycles, which is one time higher than pure Ti3C2Tx. The improvement in the specific capacity was due to the excellent electrical conductivity and the unique structure of RGO, in which a charge transfer bridge was built among the Ti3C2Tx flakes. Such a bridge shortened the transmission distance of the electrons and ions and effectively controlled the restacking of the laminated materials.

  2. Copper oxide assisted cysteine hierarchical structures for immunosensor application

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Chandra Mouli [Biomedical Instrumentation Section, CSIR-National Physical Laboratory, New Delhi 110012 (India); Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005 (India); Sumana, Gajjala, E-mail: sumanagajjala@gmail.com [Biomedical Instrumentation Section, CSIR-National Physical Laboratory, New Delhi 110012 (India); Tiwari, Ida [Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005 (India)

    2014-09-08

    The present work describes the promising electrochemical immunosensing strategy based on copper (II) assisted hierarchical cysteine structures (CuCys) varying from star to flower like morphology. The CuCys having average size of 10 μm have been synthesised using L-Cysteine as initial precursor in presence of copper oxide under environmentally friendly conditions in aqueous medium. To delineate the synthesis mechanism, detailed structural investigations have been carried out using characterization techniques such as X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The electrochemical behaviour of self-assembled CuCys on gold electrode shows surface controlled electrode reaction with an apparent electron transfer rate constant of 3.38 × 10{sup −4 }cm s{sup −1}. This innovative platform has been utilized to fabricate an immunosensor by covalently immobilizing monoclonal antibodies specific for Escherichia coli O157:H7 (E. coli). Under the optimal conditions, the fabricated immunosensor is found to be sensitive and specific for the detection of E. coli with a detection limit of 10 cfu/ml.

  3. Emission of hydrogen sulfide by leaf tissue in response to L-cysteine

    International Nuclear Information System (INIS)

    Sekiya, J.; Schmidt, A.; Wilson, L.G.; Filner, P.

    1982-01-01

    Leaf discs and detached leaves exposed to L-cysteine emitted a volatile sulfur compound which was proven by gas chromatography to be H 2 S. This phenomenon was demonstrated in all nine species tested (Cucumis sativus, Cucurbita pepo, Nicotiana tabacum, Coleus blumei, Beta vulgaris, Phaseolus vulgaris, Medicago sativa, Hordeum vulgare, and Gossypium hirsutum). The emission of volatile sulfur by cucumber leaves occurred in the dark at a similar rate to that in the light. The emission of leaf discs reached the maximal rate, more than 40 picomoles per minute per square centimeter, 2 to 4 hours after starting exposure to L-cysteine; then it decreased. In the case of detached leaves, the maximum occurred 5 to 10 h after starting exposure. The average emission rate of H 2 S during the first 4 hours from leaf discs of cucurbits in response to 10 millimolar L-cysteine, was usually more than 40 picomoles per minute per square centimeter, i.e. 0.24 micromoles per hour per square decimeter. Leaf discs exposed to 1 millimolar L-cysteine emitted only 2% as much as did the discs exposed to 10 millimolar L-cysteine. The emission from leaf discs and from detached leaves lasted for at least 5 and 15 hours, respectively. However, several hours after the maximal emission, injury of the leaves, manifested as chlorosis, was evident. H 2 S emission was a specific consequence of exposure to L-cysteine; neither D-cysteine nor L-cysteine elicited H 2 S emission. Aminooxyacetic acid, an inhibitor of pyridoxal phosphate dependent enzymes, inhibited the emission. In a cell free system from cucumber leaves, H 2 S formation and its release occurred in response to L-cysteine. Feeding experiments with [ 35 S]t-cysteine showed that most of the sulfur in H 2 S was derived from sulfur in the L-cysteine supplied

  4. Electrostatics of cysteine residues in proteins: parameterization and validation of a simple model.

    Science.gov (United States)

    Salsbury, Freddie R; Poole, Leslie B; Fetrow, Jacquelyn S

    2012-11-01

    One of the most popular and simple models for the calculation of pK(a) s from a protein structure is the semi-macroscopic electrostatic model MEAD. This model requires empirical parameters for each residue to calculate pK(a) s. Analysis of current, widely used empirical parameters for cysteine residues showed that they did not reproduce expected cysteine pK(a) s; thus, we set out to identify parameters consistent with the CHARMM27 force field that capture both the behavior of typical cysteines in proteins and the behavior of cysteines which have perturbed pK(a) s. The new parameters were validated in three ways: (1) calculation across a large set of typical cysteines in proteins (where the calculations are expected to reproduce expected ensemble behavior); (2) calculation across a set of perturbed cysteines in proteins (where the calculations are expected to reproduce the shifted ensemble behavior); and (3) comparison to experimentally determined pK(a) values (where the calculation should reproduce the pK(a) within experimental error). Both the general behavior of cysteines in proteins and the perturbed pK(a) in some proteins can be predicted reasonably well using the newly determined empirical parameters within the MEAD model for protein electrostatics. This study provides the first general analysis of the electrostatics of cysteines in proteins, with specific attention paid to capturing both the behavior of typical cysteines in a protein and the behavior of cysteines whose pK(a) should be shifted, and validation of force field parameters for cysteine residues. Copyright © 2012 Wiley Periodicals, Inc.

  5. Determination of free and total cyst(e)ine in plasma of dogs and cats.

    Science.gov (United States)

    Tôrres, Cristina L; Miller, Joshua W; Rogers, Quinton R

    2004-01-01

    In human blood, the amino acid cysteine forms disulfide bonds with itself and with other sulfhydryl compounds in their free form and with sulfhydryls in protein. Protein-bound cysteine is lost when plasma proteins are removed before amino acid analysis. The purpose of this study was to assess the time course and extent of cyst(e)ine (cysteine + half-cystine) loss in dog and cat plasma. An equal volume of 6% sulfosalicylic acid was added to plasma aliquots at 0, 2, 4, 10, 16, 24, 36, 48, 60, and 72 hours after separation of blood cells. Tris-2-carboxyethyl-phosphine hydrochloride (TCEP - HCl), a reducing agent, was used to regenerate total plasma cyst(e)ine after 3 months of sample storage (-20 degrees C). Initial free cyst(e)ine concentrations (mean +/- SEM) were higher in canine plasma (77 +/- 4 micromol/L) than in feline plasma (37 +/- 3 micromol/L). Free plasma cyst(e)ine concentrations in dogs and cats decreased after first-order kinetics, with a half-life of 23 and 69 hours, respectively. Total plasma cysteine after TCEP - HCl treatment was similar for dogs (290 micromol/L) and cats (296 micromol/L), but the percentage of free cysteine was higher (P = .02) in dogs (27%) than in cats (13%). Over half of the cyst(e)ine, homocysteine, cysteinylglycine, and glutathione were bound in vivo to plasma proteins. These results emphasize the importance of removing plasma proteins within 1 hour after blood collection for reliable assay of free plasma cyst(e)ine.

  6. Elimination of hydrogen sulphide and β substitution in cystein, catalyzed by the cysteine-lyase of hens yolk-sac and yolk (1961)

    International Nuclear Information System (INIS)

    Chapeville, F.; Fromageot, P.

    1961-01-01

    The yolk of incubated hen's eggs contains a pyridoxal phosphate activated enzyme, free of iron, copper, magnesium and calcium. This enzyme activates the β-carbon atom of cysteine. Its reactivity is demonstrated by the ease with which this β-carbon fixes various sulfur containing substances in which the sulfur has reducing properties: inorganic sulfide, sulfide or cysteine itself. In the absence of substances able to react with the β-carbon atom, the active complex, consisting of the enzyme and the aminated tri-carbon chain, is hydrolysed to pyruvic acid and ammonia. The liberation of hydrogen sulfide thus appears to be the consequence either of the substitution of the β-carbon atom of cysteine or of the decomposition of the complex which this aminoacid forms with the enzyme studied. The latter seems therefore to possess an activity which differs from the activity of the desulfhydrases as yet known. We suggest to call this enzyme cystein-lyase. (authors) [fr

  7. Cardiovascular actions of L-cysteine and L-cysteine sulfinic acid in the nucleus tractus solitarius of the rat.

    Science.gov (United States)

    Takemoto, Yumi

    2014-07-01

    The sulfur-containing excitatory amino acid (EAA) L-cysteine sulfinic acid (CSA), a neurotransmitter candidate, is endogenously synthesized from L-cysteine (Cys). Exogenous Cys administration into the brain produces cardiovascular effects; these effects likely occur via synaptic stimulation of central nervous system (CNS) neurons that regulate peripheral cardiovascular function. However, the cardiovascular responses produced by CNS Cys administration could result from CSA biosynthesized in synapse. The present study examined the role of CSA in Cys-induced cardiovascular responses within the nucleus tractus solitarius (NTS) of anesthetized rats. The NTS receives input from various visceral afferents that gate autonomic reflexes, including cardiovascular reflexes. Within the NTS, both Cys and CSA microinjections produced decrease responses in arterial blood pressure and heart rate that were similar to those produced by L-glutamate. Co-injection of the ionotropic EAA receptor antagonist kynurenic acid abolished Cys-, but not CSA-, induced cardiovascular responses. This finding suggests that only Cys-induced cardiovascular responses are mediated by kynurenate-sensitive receptors. This study provides the first demonstration that Cys- and CSA-induced cardiovascular responses occur via different mechanisms in the NTS of rats. Further, this study also indicates that Cys-induced cardiovascular responses do not occur via CSA. Thus, within the NTS, endogenous Cys and/or CSA might be involved in cardiovascular regulation.

  8. Alleviative effects of s-allyl cysteine and s-ethyl cysteine on MCD diet-induced hepatotoxicity in mice.

    Science.gov (United States)

    Lin, Chun-che; Yin, Mei-chin; Liu, Wen-hu

    2008-11-01

    Alleviative effects of s-allyl cysteine (SAC) and s-ethyl cysteine (SEC) upon methionine and choline deficient (MCD) diet-induced hepatotoxicity in mice were examined. SAC or SEC at 1g/L was added into drinking water for 7 weeks with MCD diet. MCD feeding significantly increased hepatic triglyceride and cholesterol levels, and elevated the activity of glucose-6-phosphate dehydrogenase (G6PDH), malic enzyme, fatty acid synthase (FAS) and 3-hydroxy-3-methylglutaryl coenzyme A reductase (P MCD feeding significantly lowered serum and hepatic glutathione (GSH) levels, increased malondialdehyde (MDA) and oxidized glutathione (GSSG) formation, and suppressed the activity and mRNA expression of glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (P MCD feeding significantly enhanced the mRNA expression of interleukin (IL)-1beta, IL-6, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1, matrix metalloproteinases-9 (MMP-9) and collagen-alpha1 (P MCD-induced hepatotoxicity.

  9. From nitrides to carbides: topotactic synthesis of the eta-carbides Fe3Mo3C and Co3Mo3C.

    Science.gov (United States)

    Alconchel, Silvia; Sapiña, Fernando; Martínez, Eduardo

    2004-08-21

    The molybdenum bimetallic interstitial carbides Fe(3)Mo(3)C and Co(3)Mo(3)C have been synthesized by temperature-programmed reaction (TPR) between the molybdenum bimetallic interstitial nitrides Fe(3)Mo(3)N and Co(3)Mo(3)N and a flowing mixture of CH(4) and H(2) diluted in Ar. These compounds have been characterized by X-ray diffraction, laser Raman spectroscopy, elemental analysis, energy dispersive analysis of X rays, thermal analysis (in air) and scanning electron microscopy (field emission). Their structures have been refined from X-ray powder diffraction data. These carbides crystallize in the cubic system, space group Fd3m[a= 11.11376(6) and 11.0697(3)[Angstrom] for Fe and Co compounds, respectively].

  10. Type 3c (pancreatogenic) diabetes mellitus secondary to chronic pancreatitis and pancreatic cancer

    Science.gov (United States)

    Hart, Phil A; Bellin, Melena D; Andersen, Dana K; Bradley, David; Cruz-Monserrate, Zobeida; Forsmark, Christopher E; Goodarzi, Mark O; Habtezion, Aida; Korc, Murray; Kudva, Yogish C; Pandol, Stephen J; Yadav, Dhiraj; Chari, Suresh T

    2017-01-01

    Diabetes mellitus is a group of diseases defined by persistent hyperglycaemia. Type 2 diabetes, the most prevalent form, is characterised initially by impaired insulin sensitivity and subsequently by an inadequate compensatory insulin response. Diabetes can also develop as a direct consequence of other diseases, including diseases of the exocrine pancreas. Historically, diabetes due to diseases of the exocrine pancreas was described as pancreatogenic or pancreatogenous diabetes mellitus, but recent literature refers to it as type 3c diabetes. It is important to note that type 3c diabetes is not a single entity; it occurs because of a variety of exocrine pancreatic diseases with varying mechanisms of hyperglycaemia. The most commonly identified causes of type 3c diabetes are chronic pancreatitis, pancreatic ductal adenocarcinoma, haemochromatosis, cystic fibrosis, and previous pancreatic surgery. In this Review, we discuss the epidemiology, pathogenesis, and clinical relevance of type 3c diabetes secondary to chronic pancreatitis and pancreatic ductal adenocarcinoma, and highlight several important knowledge gaps. PMID:28404095

  11. Tuning the carbon nanotube photoluminescence enhancement at addition of cysteine through the change of external conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kurnosov, N.V.; Karachevtsev, M.V.; Leontiev, V.S.; Karachevtsev, V.A., E-mail: karachevtsev@ilt.kharkov.ua

    2017-01-15

    The enhancement of the photoluminescence (PL) from the semiconducting single-walled carbon nanotubes suspended with single-stranded DNA (ssDNA) in water observed after amino acids doping is the largest at cysteine addition. The PL intensity increased through the passivation of p-defects on the carbon nanotube sidewall by the cysteine molecules due to thiol group. The effect of several external factors on the cysteine-induced enhancement of PL from carbon nanotubes covered with ssDNA was studied: UV irradiation, tip or bath sonication treatment of the suspension, the ionic strength and pH of aqueous suspension. It turned out that all these factors have an essential influence on the dependence of the PL enhancement on the cysteine concentration through inducing of additional defects on nanotube as well as a change of the nanotube surface coverage with polymer. The obtained experimental results demonstrated that PL from carbon nanotubes can be exploited successfully for the monitoring of cysteine concentration in aqueous solution. - Highlights: • Cysteine doping enhances carbon nanotube emission more than other amino acids do. • SWNT emission dependence on cysteine concentration is tuned by UV irradiation and pH. • Type of sonication treatment influences SWNT PL dependence on cysteine concentration. • Polymer coverage and defectiveness of nanotubes effect on nanotube emission. • Graphic abstract.

  12. Neuronal growth on L- and D-cysteine self-assembled monolayers reveals neuronal chiral sensitivity.

    Science.gov (United States)

    Baranes, Koby; Moshe, Hagay; Alon, Noa; Schwartz, Shmulik; Shefi, Orit

    2014-05-21

    Studying the interaction between neuronal cells and chiral molecules is fundamental for the design of novel biomaterials and drugs. Chirality influences all biological processes that involve intermolecular interaction. One common method used to study cellular interactions with different enantiomeric targets is the use of chiral surfaces. Based on previous studies that demonstrated the importance of cysteine in the nervous system, we studied the effect of L- and D-cysteine on single neuronal growth. L-Cysteine, which normally functions as a neuromodulator or a neuroprotective antioxidant, causes damage at elevated levels, which may occur post trauma. In this study, we grew adult neurons in culture enriched with L- and D-cysteine as free compounds or as self-assembled monolayers of chiral surfaces and examined the effect on the neuronal morphology and adhesion. Notably, we have found that exposure to the L-cysteine enantiomer inhibited, and even prevented, neuronal attachment more severely than exposure to the D-cysteine enantiomer. Atop the L-cysteine surfaces, neuronal growth was reduced and degenerated. Since the cysteine molecules were attached to the surface via the thiol groups, the neuronal membrane was exposed to the molecular chiral site. Thus, our results have demonstrated high neuronal chiral sensitivity, revealing chiral surfaces as indirect regulators of neuronal cells and providing a reference for studying chiral drugs.

  13. Therapeutic NOTCH3 cysteine correction in CADASIL using exon skipping: in vitro proof of concept

    NARCIS (Netherlands)

    Rutten, J.W.; Dauwerse, H.G.; Peters, D.J.; Goldfarb, A.; Venselaar, H.; Haffner, C.; Ommen, G.J. van; Aartsma-Rus, A.M.; Oberstein, S.A.

    2016-01-01

    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, or CADASIL, is a hereditary cerebral small vessel disease caused by characteristic cysteine altering missense mutations in theNOTCH3gene.NOTCH3mutations in CADASIL result in an uneven number of cysteine

  14. Cysteine as a non toxic corrosion inhibitor for copper alloys in conservation

    DEFF Research Database (Denmark)

    Gravgaard, Mari; van Lanschot, Jettie

    2012-01-01

    studies of colour changes in the corrosion products. The results obtained in this article demonstrate that cysteine could be a non-toxic alternative to BTA. Cysteine performed as well as BTA on pre-corroded coupons with bronze disease in high humidity and showed acceptable results during testing...

  15. Cysteine: a conditionally essential amino acid in low-birth-weight preterm infants?

    NARCIS (Netherlands)

    Riedijk, Maaike A.; van Beek, Ron H. T.; Voortman, Gardi; de Bie, Henrica M. A.; Dassel, Anne C. M.; van Goudoever, Johannes B.

    2007-01-01

    Cyst(e)ine can be synthesized de novo from methionine and serine and is, therefore, a nonessential amino acid in human adults. Several studies have suggested that cyst(e)ine might be a conditionally essential amino acid in preterm infants because of biochemical immaturity. No data are available on

  16. Relationships between tobacco leaf δ"1"3C and physiological characteristics

    International Nuclear Information System (INIS)

    Wang Yi; Song Pengfei; Yan Kan; Tan Shuwen; Wu Xiaoxiao; Chen Zongyu

    2013-01-01

    In this paper, the flue-cured tobacco K326 was employed to study the abundance of carbon isotope composition, photosynthetic pigment content, soluble protein content and leaf mass per area (LMA) of tobacco leaf which were grown at four testing sites of different altitude (T_1, T_2, T_3, T_4). The correlations of carbon isotope composition with altitude, leaf position and physiological measures were understood as well. Results showed that δ"1"3C of those samples varied from -27.4‰ to -23.4‰. The δ"1"3C of samples from T_1, T_2and T_3 were increased with rising of the leaf position. δ"1"3C of middle and upper leaves from T_1, T_2and T_3 were positively correlated with altitude. However, δ"1"3C of samples from T_4 ranging from -26.8‰ to -26.4‰ was lower than the values from previous samples. The δ"1"3C also decreased with the increasing of leaf position, and was significantly negatively correlated with chlorophyll content and chlorophyll/carotinoid ratio (P < 0.05). The δ"1"3C was not significantly correlated with carotinoid content and chlorophyll a/b ratio. Meanwhile, it was positively correlated with soluble protein content and LMA significantly (P < 0.01). Generally, our findings indicated that chlorophyll content, chlorophyll/carotenoid ratio, soluble protein content, and LMA had strong relationships with δ"1"3C, whereas the relationship of δ"1"3C with altitude and leaf position was still unclear. (authors)

  17. Resolution of oxidative stress by thioredoxin reductase: Cysteine versus selenocysteine

    Directory of Open Access Journals (Sweden)

    Brian Cunniff

    2014-01-01

    Full Text Available Thioredoxin reductase (TR catalyzes the reduction of thioredoxin (TRX, which in turn reduces mammalian typical 2-Cys peroxiredoxins (PRXs 1–4, thiol peroxidases implicated in redox homeostasis and cell signaling. Typical 2-Cys PRXs are inactivated by hyperoxidation of the peroxidatic cysteine to cysteine-sulfinic acid, and regenerated in a two-step process involving retro-reduction by sulfiredoxin (SRX and reduction by TRX. Here transient exposure to menadione and glucose oxidase was used to examine the dynamics of oxidative inactivation and reactivation of PRXs in mouse C10 cells expressing various isoforms of TR, including wild type cytoplasmic TR1 (Sec-TR1 and mitochondrial TR2 (Sec-TR2 that encode selenocysteine, as well as mutants of TR1 and TR2 in which the selenocysteine codon was changed to encode cysteine (Cys-TR1 or Cys-TR2. In C10 cells endogenous TR activity was insensitive to levels of hydrogen peroxide that hyperoxidize PRXs. Expression of Sec-TR1 increased TR activity, reduced the basal cytoplasmic redox state, and increased the rate of reduction of a redox-responsive cytoplasmic GFP probe (roGFP, but did not influence either the rate of inactivation or the rate of retro-reduction of PRXs. In comparison to roGFP, which was reduced within minutes once oxidants were removed reduction of 2-Cys PRXs occurred over many hours. Expression of wild type Sec-TR1 or Sec-TR2, but not Cys-TR1 or TR2, increased the rate of reduction of PRXs and improved cell survival after menadione exposure. These results indicate that expression levels of TR do not reduce the severity of initial oxidative insults, but rather govern the rate of reduction of cellular factors required for cell viability. Because Sec-TR is completely insensitive to cytotoxic levels of hydrogen peroxide, we suggest TR functions at the top of a redox pyramid that governs the oxidation state of peroxiredoxins and other protein factors, thereby dictating a hierarchy of phenotypic

  18. Despite phylogenetic effects, C3-C4 lineages bridge the ecological gap to C4 photosynthesis.

    Science.gov (United States)

    Lundgren, Marjorie R; Christin, Pascal-Antoine

    2017-01-01

    C 4 photosynthesis is a physiological innovation involving several anatomical and biochemical components that emerged recurrently in flowering plants. This complex trait evolved via a series of physiological intermediates, broadly termed 'C 3 -C 4 ', which have been widely studied to understand C 4 origins. While this research program has focused on biochemistry, physiology, and anatomy, the ecology of these intermediates remains largely unexplored. Here, we use global occurrence data and local habitat descriptions to characterize the niches of multiple C 3 -C 4 lineages, as well as their close C 3 and C 4 relatives. While C 3 -C 4 taxa tend to occur in warm climates, their abiotic niches are spread along other dimensions, making it impossible to define a universal C 3 -C 4 niche. Phylogeny-based comparisons suggest that, despite shifts associated with photosynthetic types, the precipitation component of the C 3 -C 4 niche is particularly lineage specific, being highly correlated with that of closely related C 3 and C 4 taxa. Our large-scale analyses suggest that C 3 -C 4 lineages converged toward warm habitats, which may have facilitated the transition to C 4 photosynthesis, effectively bridging the ecological gap between C 3 and C 4 plants. The intermediates retained some precipitation aspects of their C 3 ancestors' habitat, and likely transmitted them to their C 4 descendants, contributing to the diversity among C 4 lineages seen today. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  19. Replication of murine coronavirus requires multiple cysteines in the endodomain of spike protein

    International Nuclear Information System (INIS)

    Yang, Jinhua; Lv, Jun; Wang, Yuyan; Gao, Shuang; Yao, Qianqian; Qu, Di; Ye, Rong

    2012-01-01

    A conserved cysteine-rich motif located between the transmembrane domain and the endodomain is essential for membrane fusion and assembly of coronavirus spike (S) protein. Here, we proved that three cysteines within the motif, but not dependent on position, are minimally required for the survival of the recombinant mouse hepatitis virus. When the carboxy termini with these mutated motifs of S proteins were respectively introduced into a heterogeneous protein, both incorporation into lipid rafts and S-palmitoylation of these recombinant proteins showed a similar quantity requirement to cysteine residues. Meanwhile, the redistribution of these proteins on cellular surface indicated that the absence of the positively charged rather than cysteine residues in the motif might lead the dramatic reduction in syncytial formation of some mutants with the deleted motifs. These results suggest that multiple cysteine as well as charged residues concurrently improves the membrane-associated functions of S protein in viral replication and cytopathogenesis.

  20. Cysteine 138 mutation in HIV-1 Nef from patients with delayed disease progression

    DEFF Research Database (Denmark)

    Tolstrup, Martin; Laursen, Alex Lund; Gerstoft, J.

    2006-01-01

    on the delayed disease status. However, the results demonstrate a high incidence of a single amino acid polymorphism (cysteine 138) in HIV-1 Nef. The allelic frequency of cysteine 138 between the delayed disease progression group and the progressor group was found to be statistically significant (P = 0.......0139). The phylogeny of isolates was investigated and the variants harbouring the cysteine 138 mutation clustered independently. CONCLUSION: The present study describes a viral genetic polymorphism related to AIDS disease progression. The polymorphism (cysteine 138) has previously been reported to confer decreased...... viral replication (Premkumar DR, et al. AIDS Res Hum Retroviruses 1996; 12(4): 337-45). A sequence database search for comparative mutations revealed a high frequency of cysteine 138 in patients with reported SP AIDS...

  1. Intramolecular synergistic effect of glutamic acid, cysteine and glycine against copper corrosion in hydrochloric acid solution

    International Nuclear Information System (INIS)

    Zhang Daquan; Xie Bin; Gao Lixin; Cai Qirui; Joo, Hyung Goun; Lee, Kang Yong

    2011-01-01

    The corrosion protection of copper by glutamic acid, cysteine, glycine and their derivative (glutathione) in 0.5 M hydrochloric acid solution has been studied by the electrochemical impedance spectroscopy and cyclic voltammetry. The inhibition efficiency of the organic inhibitors on copper corrosion increases in the order: glutathione > cysteine > cysteine + glutamic acid + glycine > glutamic acid > glycine. Maximum inhibition efficiency for cysteine reaches about 92.9% at 15 mM concentration level. The glutathione can give 96.4% inhibition efficiency at a concentration of 10 mM. The molecular structure parameters were obtained by PM3 (Parametric Method 3) semi-empirical calculation. The intramolecular synergistic effect of glutamic acid, cysteine and glycine moieties in glutathione is attributed to the lower energy of the lowest unoccupied molecular orbital (E LUMO ) level and to the excess hetero-atom adsorption centers and the bigger coverage on the copper surface.

  2. Replication of murine coronavirus requires multiple cysteines in the endodomain of spike protein

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jinhua; Lv, Jun; Wang, Yuyan; Gao, Shuang; Yao, Qianqian; Qu, Di; Ye, Rong, E-mail: yerong24@fudan.edu.cn

    2012-06-05

    A conserved cysteine-rich motif located between the transmembrane domain and the endodomain is essential for membrane fusion and assembly of coronavirus spike (S) protein. Here, we proved that three cysteines within the motif, but not dependent on position, are minimally required for the survival of the recombinant mouse hepatitis virus. When the carboxy termini with these mutated motifs of S proteins were respectively introduced into a heterogeneous protein, both incorporation into lipid rafts and S-palmitoylation of these recombinant proteins showed a similar quantity requirement to cysteine residues. Meanwhile, the redistribution of these proteins on cellular surface indicated that the absence of the positively charged rather than cysteine residues in the motif might lead the dramatic reduction in syncytial formation of some mutants with the deleted motifs. These results suggest that multiple cysteine as well as charged residues concurrently improves the membrane-associated functions of S protein in viral replication and cytopathogenesis.

  3. Mass spectrometric analysis of L-cysteine metabolism: physiological role and fate of L-cysteine in the enteric protozoan parasite Entamoeba histolytica.

    Science.gov (United States)

    Jeelani, Ghulam; Sato, Dan; Soga, Tomoyoshi; Watanabe, Haruo; Nozaki, Tomoyoshi

    2014-11-04

    L-cysteine is essential for virtually all living organisms, from bacteria to higher eukaryotes. Besides having a role in the synthesis of virtually all proteins and of taurine, cysteamine, glutathione, and other redox-regulating proteins, L-cysteine has important functions under anaerobic/microaerophilic conditions. In anaerobic or microaerophilic protozoan parasites, such as Entamoeba histolytica, L-cysteine has been implicated in growth, attachment, survival, and protection from oxidative stress. However, a specific role of this amino acid or related metabolic intermediates is not well understood. In this study, using stable-isotope-labeled L-cysteine and capillary electrophoresis-time of flight mass spectrometry, we investigated the metabolism of L-cysteine in E. histolytica. [U-(13)C3, (15)N]L-cysteine was rapidly metabolized into three unknown metabolites, besides L-cystine and L-alanine. These metabolites were identified as thiazolidine-4-carboxylic acid (T4C), 2-methyl thiazolidine-4-carboxylic acid (MT4C), and 2-ethyl-thiazolidine-4-carboxylic acid (ET4C), the condensation products of L-cysteine with aldehydes. We demonstrated that these 2-(R)-thiazolidine-4-carboxylic acids serve for storage of L-cysteine. Liberation of L-cysteine occurred when T4C was incubated with amebic lysates, suggesting enzymatic degradation of these L-cysteine derivatives. Furthermore, T4C and MT4C significantly enhanced trophozoite growth and reduced intracellular reactive oxygen species (ROS) levels when it was added to cultures, suggesting that 2-(R)-thiazolidine-4-carboxylic acids are involved in the defense against oxidative stress. Amebiasis is a human parasitic disease caused by the protozoan parasite Entamoeba histolytica. In this parasite, L-cysteine is the principal low-molecular-weight thiol and is assumed to play a significant role in supplying the amino acid during trophozoite invasion, particularly when the parasites move from the anaerobic intestinal lumen to highly

  4. Aspartic acid-promoted highly selective and sensitive colorimetric sensing of cysteine in rat brain.

    Science.gov (United States)

    Qian, Qin; Deng, Jingjing; Wang, Dalei; Yang, Lifen; Yu, Ping; Mao, Lanqun

    2012-11-06

    Direct selective determination of cysteine in the cerebral system is of great importance because of the crucial roles of cysteine in physiological and pathological processes. In this study, we report a sensitive and selective colorimetric assay for cysteine in the rat brain with gold nanoparticles (Au-NPs) as the signal readout. Initially, Au-NPs synthesized with citrate as the stabilizer are red in color and exhibit absorption at 520 nm. The addition of an aqueous solution (20 μL) of cysteine or aspartic acid alone to a 200 μL Au-NP dispersion causes no aggregation, while the addition of an aqueous solution of cysteine into a Au-NP dispersion containing aspartic acid (1.8 mM) causes the aggregation of Au-NPs and thus results in the color change of the colloid from wine red to blue. These changes are ascribed to the ion pair interaction between aspartic acid and cysteine on the interface between Au-NPs and solution. The concentration of cysteine can be visualized with the naked eye and determined by UV-vis spectroscopy. The signal output shows a linear relationship for cysteine within the concentration range from 0.166 to 1.67 μM with a detection limit of 100 nM. The assay demonstrated here is highly selective and is free from the interference of other natural amino acids and other thiol-containing species as well as the species commonly existing in the brain such as lactate, ascorbic acid, and glucose. The basal dialysate level of cysteine in the microdialysate from the striatum of adult male Sprague-Dawley rats is determined to be around 9.6 ± 2.1 μM. The method demonstrated here is facile but reliable and durable and is envisaged to be applicable to understanding the chemical essence involved in physiological and pathological events associated with cysteine.

  5. Development of 68Ga ethyl cysteinate dimer for PET studies

    International Nuclear Information System (INIS)

    Alireza Mirzaei; Jalilian, A.R.; Gholamali Shabani; Ashraf Fakhari; Mehdi Akhlaghi; Davood Beiki

    2016-01-01

    In this work development of 68 Ga-ethyl cysteinate dimer ( 68 Ga-ECD) a 68 Ga tracer for possible cerebral blood flow based on 99m Tc ECD homolog is reported. 68 Ga-ECD was prepared using generator-based 68 GaCl 3 and ECD at optimized conditions. Quality control, stability, partition co-efficient and the biodistribution of the tracer (by tissue counting and PET/CT in rats) was studied. Significant metabolism of the lipophilic tracer into water soluble metabolite(s) led to urinary excretion of the tracer, un-comparable to that of homologous 99m Tc-compound. Cardiac uptake of the complex suggests formation of a possible lipophil cationic complex and/or metabolite. (author)

  6. Unusual hydrogen bonding in L-cysteine hydrogen fluoride.

    Science.gov (United States)

    Minkov, V S; Ghazaryan, V V; Boldyreva, E V; Petrosyan, A M

    2015-08-01

    L-Cysteine hydrogen fluoride, or bis(L-cysteinium) difluoride-L-cysteine-hydrogen fluoride (1/1/1), 2C3H8NO2S(+)·2F(-)·C3H7NO2S·HF or L-Cys(+)(L-Cys···L-Cys(+))F(-)(F(-)...H-F), provides the first example of a structure with cations of the 'triglycine sulfate' type, i.e. A(+)(A···A(+)) (where A and A(+) are the zwitterionic and cationic states of an amino acid, respectively), without a doubly charged counter-ion. The salt crystallizes in the monoclinic system with the space group P2(1). The dimeric (L-Cys···L-Cys(+)) cation and the dimeric (F(-)···H-F) anion are formed via strong O-H···O or F-H···F hydrogen bonds, respectively, with very short O···O [2.4438 (19) Å] and F···F distances [2.2676 (17) Å]. The F···F distance is significantly shorter than in solid hydrogen fluoride. Additionally, there is another very short hydrogen bond, of O-H···F type, formed by a L-cysteinium cation and a fluoride ion. The corresponding O···F distance of 2.3412 (19) Å seems to be the shortest among O-H···F and F-H···O hydrogen bonds known to date. The single-crystal X-ray diffraction study was complemented by IR spectroscopy. Of special interest was the spectral region of vibrations related to the above-mentioned hydrogen bonds.

  7. Cysteine modified polyaniline films improve biocompatibility for two cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Yslas, Edith I., E-mail: eyslas@exa.unrc.edu.ar [Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina); Cavallo, Pablo; Acevedo, Diego F.; Barbero, César A. [Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina); Rivarola, Viviana A. [Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina)

    2015-06-01

    This work focuses on one of the most exciting application areas of conjugated conducting polymers, which is cell culture and tissue engineering. To improve the biocompatibility of conducting polymers we present an easy method that involves the modification of the polymer backbone using L-cysteine. In this publication, we show the synthesis of polyaniline (PANI) films supported onto Polyethylene terephthalate (PET) films, and modified using cysteine (PANI-Cys) in order to generate a biocompatible substrate for cell culture. The PANI-Cys films are characterized by Fourier Transform infrared and UV–visible spectroscopy. The changes in the hydrophilicity of the polymer films after and before the modification were tested using contact angle measurements. After modification the contact angle changes from 86° ± 1 to 90° ± 1, suggesting a more hydrophylic surface. The adhesion properties of LM2 and HaCaT cell lines on the surface of PANI-Cys films in comparison with tissue culture plastic (TCP) are studied. The PANI-Cys film shows better biocompatibility than PANI film for both cell lines. The cell morphologies on the TCP and PANI-Cys film were examined by florescence and Atomic Force Microscopy (AFM). Microscopic observations show normal cellular behavior when PANI-Cys is used as a substrate of both cell lines (HaCaT and LM2) as when they are cultured on TCP. The ability of these PANI-Cys films to support cell attachment and growth indicates their potential use as biocompatible surfaces and in tissue engineering. - Highlights: • A new surface PANI-Cys was produced on films of polyethylene terephthalate. • The relationship between surface characteristics and biocompatibility is analyzed. • The PANI-Cys film presents good biocompatibility for two cell lines.

  8. Quercetin targets cysteine string protein (CSPalpha and impairs synaptic transmission.

    Directory of Open Access Journals (Sweden)

    Fenglian Xu

    2010-06-01

    Full Text Available Cysteine string protein (CSPalpha is a synaptic vesicle protein that displays unique anti-neurodegenerative properties. CSPalpha is a member of the conserved J protein family, also called the Hsp40 (heat shock protein of 40 kDa protein family, whose importance in protein folding has been recognized for many years. Deletion of the CSPalpha in mice results in knockout mice that are normal for the first 2-3 weeks of life followed by an unexplained presynaptic neurodegeneration and premature death. How CSPalpha prevents neurodegeneration is currently not known. As a neuroprotective synaptic vesicle protein, CSPalpha represents a promising therapeutic target for the prevention of neurodegenerative disorders.Here, we demonstrate that the flavonoid quercetin promotes formation of stable CSPalpha-CSPalpha dimers and that quercetin-induced dimerization is dependent on the unique cysteine string region. Furthermore, in primary cultures of Lymnaea neurons, quercetin induction of CSPalpha dimers correlates with an inhibition of synapse formation and synaptic transmission suggesting that quercetin interfers with CSPalpha function. Quercetin's action on CSPalpha is concentration dependent and does not promote dimerization of other synaptic proteins or other J protein family members and reduces the assembly of CSPalpha:Hsc70 units (70kDa heat shock cognate protein.Quercetin is a plant derived flavonoid and popular nutritional supplement proposed to prevent memory loss and altitude sickness among other ailments, although its precise mechanism(s of action has been unclear. In view of the therapeutic promise of upregulation of CSPalpha and the undesired consequences of CSPalpha dysfunction, our data establish an essential proof of principle that pharmaceutical agents can selectively target the neuroprotective J protein CSPalpha.

  9. Recent Advances in Layered Ti3 C2 Tx MXene for Electrochemical Energy Storage.

    Science.gov (United States)

    Xiong, Dongbin; Li, Xifei; Bai, Zhimin; Lu, Shigang

    2018-04-01

    Ti 3 C 2 T x , a typical representative among the emerging family of 2D layered transition metal carbides and/or nitrides referred to as MXenes, has exhibited multiple advantages including metallic conductivity, a plastic layer structure, small band gaps, and the hydrophilic nature of its functionalized surface. As a result, this 2D material is intensively investigated for application in the energy storage field. The composition, morphology and texture, surface chemistry, and structural configuration of Ti 3 C 2 T x directly influence its electrochemical performance, e.g., the use of a well-designed 2D Ti 3 C 2 T x as a rechargeable battery anode has significantly enhanced battery performance by providing more chemically active interfaces, shortened ion-diffusion lengths, and improved in-plane carrier/charge-transport kinetics. Some recent progresses of Ti 3 C 2 T x MXene are achieved in energy storage. This Review summarizes recent advances in the synthesis and electrochemical energy storage applications of Ti 3 C 2 T x MXene including supercapacitors, lithium-ion batteries, sodium-ion batteries, and lithium-sulfur batteries. The current opportunities and future challenges of Ti 3 C 2 T x MXene are addressed for energy-storage devices. This Review seeks to provide a rational and in-depth understanding of the relation between the electrochemical performance and the nanostructural/chemical composition of Ti 3 C 2 T x , which will promote the further development of 2D MXenes in energy-storage applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Synthesis and antiviral activity of 3'-deoxy-3'-C-hydroxymethyl nucleosides.

    Science.gov (United States)

    Bamford, M J; Coe, P L; Walker, R T

    1990-09-01

    A series of 3'-branched-chain sugar nucleosides, in particular 3'-deoxy-3'-C-hydroxmethyl nucleosides, have been synthesized and evaluated as antiviral agents. Reaction of 1-(2,3-epoxy-5-O-trityl-beta-D-lyxo-pentofuranosyl) derivatives 12 and 13, of uracil and thymine, respectively, with 5,6-dihydro-2-lithio-5-methyl-1,3,5-dithiazine 14 afforded the corresponding 3'-functionalized nucleosides 15 and 16, respectively. Replacement of the trityl group with tertbutyldiphenylsilyl allowed high yielding hydrolysis of the 3'-function to give the 3'-deoxy-3'-C-formyl-beta-D-arabino-pentofuranosyl nucleosides 21 and 22. Desilylation afforded the 1-(3-deoxy-3-C-formyl-beta- D-lyxo-pentofuranosyl) 3',5'-O-hemiacetal nucleosides 33 and 34, respectively. Reduction of the formyl group of 21 and 22, followed by desilylation, yielded the 3'-deoxy-3'-C-(hydroxymethyl)-beta-D-arabino- pentofuranosyl) analogues 7 and 8, respectively. The uracil base moiety of 7 was converted to 5-iodouracil and then to (E)-5-(2-bromovinyl)uracil to furnish an analogue 10 of BVaraU. The 1-(3-deoxy-3-C-(hydroxymethyl)-beta-D-lyxo-pentofuranosyl) and 1-(2,3-dideoxy-3-C-(hydroxymethyl)-beta-D-erythro-pentofuranosyl) derivatives of uracil (31 and 6, respectively) and 5-iodouracil (32 and 9, respectively) were also obtained. All novel, fully deprotected nucleoside analogues were evaluated for antiviral activity against human immunodeficiency virus type-1, herpes simplex virus types-1 and -2, varicella zoster virus, human cytomegalovirus and influenza A. Of the compounds tested only (E)-5-(2-bromovinyl)-1-[3-deoxy- 3-C-(hydroxymethyl)-beta-D-arabino-pentofuranosyl]uracil (10) inhibited VZV (alone), but did so at concentrations well below the cytotoxicity threshold.

  11. Mutations of 3c and spike protein genes correlate with the occurrence of feline infectious peritonitis.

    Science.gov (United States)

    Bank-Wolf, Barbara Regina; Stallkamp, Iris; Wiese, Svenja; Moritz, Andreas; Tekes, Gergely; Thiel, Heinz-Jürgen

    2014-10-10

    The genes encoding accessory proteins 3a, 3b, 3c, 7a and 7b, the S2 domain of the spike (S) protein gene and the membrane (M) protein gene of feline infectious peritonitis virus (FIPV) and feline enteric coronavirus (FECV) samples were amplified, cloned and sequenced. For this faeces and/or ascites samples from 19 cats suffering from feline infectious peritonitis (FIP) as well as from 20 FECV-infected healthy cats were used. Sequence comparisons revealed that 3c genes of animals with FIP were heavily affected by nucleotide deletions and point mutations compared to animals infected with FECV; these alterations resulted either in early termination or destruction of the translation initiation codon. Two ascites-derived samples of cats with FIP which displayed no alterations of ORF3c harboured mutations in the S2 domain of the S protein gene which resulted in amino acid exchanges or deletions. Moreover, changes in 3c were often accompanied by mutations in S2. In contrast, in samples obtained from faeces of healthy cats, the ORF3c was never affected by such mutations. Similarly ORF3c from faecal samples of the cats with FIP was mostly intact and showed only in a few cases the same mutations found in the respective ascites samples. The genes encoding 3a, 3b, 7a and 7b displayed no mutations linked to the feline coronavirus (FCoV) biotype. The M protein gene was found to be conserved between FECV and FIPV samples. Our findings suggest that mutations of 3c and spike protein genes correlate with the occurrence of FIP. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Characterization and sequence analysis of cysteine and glycine-rich ...

    African Journals Online (AJOL)

    Tarek

    2011-04-18

    Apr 18, 2011 ... nucleotide alignment of both native buffalo and cattle CSRP3 cDNAs sequences ..... Exon III, Identities = 71/75 (94%), Gaps = 1/75 (1%) Strand=Plus/Plus ... Band MR, Larson JH, Rebeiz M, Green CA, Heyen DW, Donovan J,.

  13. Nonacarbonyl-1κ3C,2κ3C,3κ3C-μ-bis(diphenylarsinomethane-1:2κ2As:As'-[tris(2-chloroethyl phosphite-3κP]-triangulo-triruthenium(0

    Directory of Open Access Journals (Sweden)

    Omar bin Shawkataly

    2010-08-01

    Full Text Available In the title triangulo-triruthenium(0 compound, [Ru3(C25H22As2(C6H12Cl3O3P(CO9], the bis(diphenylarsinomethane ligand bridges an Ru—Ru bond and the monodentate phosphine ligand bonds to the third Ru atom. Both the arsine and phosphine ligands are equatorial with respect to the Ru3 triangle. In addition, each Ru atom carries one equatorial and two axial terminal carbonyl ligands. In the crystal packing, the molecules are linked by intermolecular C—H...O hydrogen bonds into a three-dimensional framework. Weak intermolecular C—H...π interactions further stabilize the crystal structure.

  14. Selective sp3 C-H alkylation via polarity-match-based cross-coupling.

    Science.gov (United States)

    Le, Chip; Liang, Yufan; Evans, Ryan W; Li, Ximing; MacMillan, David W C

    2017-07-06

    The functionalization of carbon-hydrogen (C-H) bonds is one of the most attractive strategies for molecular construction in organic chemistry. The hydrogen atom is considered to be an ideal coupling handle, owing to its relative abundance in organic molecules and its availability for functionalization at almost any stage in a synthetic sequence. Although many C-H functionalization reactions involve C(sp 3 )-C(sp 2 ) coupling, there is a growing demand for C-H alkylation reactions, wherein sp 3 C-H bonds are replaced with sp 3 C-alkyl groups. Here we describe a polarity-match-based selective sp 3 C-H alkylation via the combination of photoredox, nickel and hydrogen-atom transfer catalysis. This methodology simultaneously uses three catalytic cycles to achieve hydridic C-H bond abstraction (enabled by polarity matching), alkyl halide oxidative addition, and reductive elimination to enable alkyl-alkyl fragment coupling. The sp 3 C-H alkylation is highly selective for the α-C-H of amines, ethers and sulphides, which are commonly found in pharmaceutically relevant architectures. This cross-coupling protocol should enable broad synthetic applications in de novo synthesis and late-stage functionalization chemistry.

  15. Sema3C Promotes the Survival and Tumorigenicity of Glioma Stem Cells through Rac1 Activation

    Directory of Open Access Journals (Sweden)

    Jianghong Man

    2014-12-01

    Full Text Available Summary: Different cancer cell compartments often communicate through soluble factors to facilitate tumor growth. Glioma stem cells (GSCs are a subset of tumor cells that resist standard therapy to contribute to disease progression. How GSCs employ a distinct secretory program to communicate with and nurture each other over the nonstem tumor cell (NSTC population is not well defined. Here, we show that GSCs preferentially secrete Sema3C and coordinately express PlexinA2/D1 receptors to activate Rac1/nuclear factor (NF-κB signaling in an autocrine/paracrine loop to promote their own survival. Importantly, Sema3C is not expressed in neural progenitor cells (NPCs or NSTCs. Disruption of Sema3C induced apoptosis of GSCs, but not NPCs or NSTCs, and suppressed tumor growth in orthotopic models of glioblastoma. Introduction of activated Rac1 rescued the Sema3C knockdown phenotype in vivo. Our study supports the targeting of Sema3C to break this GSC-specific autocrine/paracrine loop in order to improve glioblastoma treatment, potentially with a high therapeutic index. : Glioma stem cells (GSCs have a high capacity for self-renewal, invasion, and survival. How they communicate with each other to survive and maintain their identity is not clear. Man et al. now show that GSCs have co-opted a neurodevelopmental program to activate Rac1 to promote defining features of GSCs.

  16. A Single Nucleotide Polymorphism in Human APOBEC3C Enhances Restriction of Lentiviruses.

    Directory of Open Access Journals (Sweden)

    Cristina J Wittkopp

    2016-10-01

    Full Text Available Humans express seven human APOBEC3 proteins, which can inhibit viruses and endogenous retroelements through cytidine deaminase activity. The seven paralogs differ in the potency of their antiviral effects, as well as in their antiviral targets. One APOBEC3, APOBEC3C, is exceptional as it has been found to only weakly block viruses and endogenous retroelements compared to other APOBEC3s. However, our positive selection analyses suggest that APOBEC3C has played a role in pathogen defense during primate evolution. Here, we describe a single nucleotide polymorphism in human APOBEC3C, a change from serine to isoleucine at position 188 (I188 that confers potent antiviral activity against HIV-1. The gain-of-function APOBEC3C SNP results in increased enzymatic activity and hypermutation of target sequences when tested in vitro, and correlates with increased dimerization of the protein. The I188 is widely distributed in human African populations, and is the ancestral primate allele, but is not found in chimpanzees or gorillas. Thus, while other hominids have lost activity of this antiviral gene, it has been maintained, or re-acquired, as a more active antiviral gene in a subset of humans. Taken together, our results suggest that APOBEC3C is in fact involved in protecting hosts from lentiviruses.

  17. Selective sp3 C-H alkylation via polarity-match-based cross-coupling

    Science.gov (United States)

    Le, Chip; Liang, Yufan; Evans, Ryan W.; Li, Ximing; MacMillan, David W. C.

    2017-07-01

    The functionalization of carbon-hydrogen (C-H) bonds is one of the most attractive strategies for molecular construction in organic chemistry. The hydrogen atom is considered to be an ideal coupling handle, owing to its relative abundance in organic molecules and its availability for functionalization at almost any stage in a synthetic sequence. Although many C-H functionalization reactions involve C(sp3)-C(sp2) coupling, there is a growing demand for C-H alkylation reactions, wherein sp3 C-H bonds are replaced with sp3 C-alkyl groups. Here we describe a polarity-match-based selective sp3 C-H alkylation via the combination of photoredox, nickel and hydrogen-atom transfer catalysis. This methodology simultaneously uses three catalytic cycles to achieve hydridic C-H bond abstraction (enabled by polarity matching), alkyl halide oxidative addition, and reductive elimination to enable alkyl-alkyl fragment coupling. The sp3 C-H alkylation is highly selective for the α-C-H of amines, ethers and sulphides, which are commonly found in pharmaceutically relevant architectures. This cross-coupling protocol should enable broad synthetic applications in de novo synthesis and late-stage functionalization chemistry.

  18. Mutation of the S and 3c genes in genomes of feline coronaviruses.

    Science.gov (United States)

    Oguma, Keisuke; Ohno, Megumi; Yoshida, Mayuko; Sentsui, Hiroshi

    2018-05-17

    Feline coronavirus (FCoV) is classified into two biotypes based on its pathogenicity in cats: a feline enteric coronavirus of low pathogenicity and a highly virulent feline infectious peritonitis virus. It has been suspected that FCoV alters its biotype via mutations in the viral genome. The S and 3c genes of FCoV have been considered the candidates for viral pathogenicity conversion. In the present study, FCoVs were analyzed for the frequency and location of mutations in the S and 3c genes from faecal samples of cats in an animal shelter and the faeces, effusions, and tissues of cats that were referred to veterinary hospitals. Our results indicated that approximately 95% FCoVs in faeces did not carry mutations in the two genes. However, 80% FCoVs in effusion samples exhibited mutations in the S and 3c genes with remainder displaying a mutation in the S or 3c gene. It was also suggested that mutational analysis of the 3c gene could be useful for studying the horizontal transmission of FCoVs in multi-cat environments.

  19. Knockout of the murine cysteine dioxygenase gene results in severe impairment in ability to synthesize taurine and an increased catabolism of cysteine to hydrogen sulfide

    Science.gov (United States)

    Ueki, Iori; Roman, Heather B.; Valli, Alessandro; Fieselmann, Krista; Lam, Jimmy; Peters, Rachel; Hirschberger, Lawrence L.

    2011-01-01

    Cysteine homeostasis is dependent on the regulation of cysteine dioxygenase (CDO) in response to changes in sulfur amino acid intake. CDO oxidizes cysteine to cysteinesulfinate, which is further metabolized to either taurine or to pyruvate plus sulfate. To gain insight into the physiological function of CDO and the consequence of a loss of CDO activity, mice carrying a null CDO allele (CDO+/− mice) were crossed to generate CDO−/−, CDO+/−, and CDO+/+ mice. CDO−/− mice exhibited postnatal mortality, growth deficit, and connective tissue pathology. CDO−/− mice had extremely low taurine levels and somewhat elevated cysteine levels, consistent with the lack of flux through CDO-dependent catabolic pathways. However, plasma sulfate levels were slightly higher in CDO−/− mice than in CDO+/− or CDO+/+ mice, and tissue levels of acid-labile sulfide were elevated, indicating an increase in cysteine catabolism by cysteine desulfhydration pathways. Null mice had lower hepatic cytochrome c oxidase levels, suggesting impaired electron transport capacity. Supplementation of mice with taurine improved survival of male pups but otherwise had little effect on the phenotype of the CDO−/− mice. H2S has been identified as an important gaseous signaling molecule as well as a toxicant, and pathology may be due to dysregulation of H2S production. Control of cysteine levels by regulation of CDO may be necessary to maintain low H2S/sulfane sulfur levels and facilitate the use of H2S as a signaling molecule. PMID:21693692

  20. Facile and green synthesis of highly stable L-cysteine functionalized copper nanoparticles

    International Nuclear Information System (INIS)

    Kumar, Nikhil; Upadhyay, Lata Sheo Bachan

    2016-01-01

    Highlights: • A facile and eco-friendly method for the synthesis of L-cysteine functionalized copper nanoparticles is reported. • Synthesis of Highly stable L-cysteine functionalized copper nanoparticles (∼40 nm) was done in an aqueous medium. • FTIR analysis shows that L-cysteine bound to the nanoparticle surface via thiol group. - Abstract: A simple eco-friendly method for L-cysteine capped copper nanoparticles (CCNPs) synthesis in aqueous solution has been developed. Glucose and L-cysteine were used as reducing agent and capping/functionalizing agent, respectively. Different parameters such as capping agent concentration, pH, reaction temperature, and reducing agent concentration were optimized during the synthesis. The L-cysteine capped copper nanoparticle were characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, Particle size and zeta potential analyser, and high resolution transmission electron microscopy. Spherical shaped cysteine functionalized/capped copper nanoparticles with an average size of 40 nm were found to be highly stable at room temperature (RT) for a period of 1 month

  1. Facile and green synthesis of highly stable L-cysteine functionalized copper nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Nikhil, E-mail: nkumar.phd2011.bt@nitrr.ac.in; Upadhyay, Lata Sheo Bachan, E-mail: contactlataupadhyay@gmail.com

    2016-11-01

    Highlights: • A facile and eco-friendly method for the synthesis of L-cysteine functionalized copper nanoparticles is reported. • Synthesis of Highly stable L-cysteine functionalized copper nanoparticles (∼40 nm) was done in an aqueous medium. • FTIR analysis shows that L-cysteine bound to the nanoparticle surface via thiol group. - Abstract: A simple eco-friendly method for L-cysteine capped copper nanoparticles (CCNPs) synthesis in aqueous solution has been developed. Glucose and L-cysteine were used as reducing agent and capping/functionalizing agent, respectively. Different parameters such as capping agent concentration, pH, reaction temperature, and reducing agent concentration were optimized during the synthesis. The L-cysteine capped copper nanoparticle were characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, Particle size and zeta potential analyser, and high resolution transmission electron microscopy. Spherical shaped cysteine functionalized/capped copper nanoparticles with an average size of 40 nm were found to be highly stable at room temperature (RT) for a period of 1 month.

  2. The mechanism of cysteine detection in biological media by means of vanadium oxide nanoparticles

    International Nuclear Information System (INIS)

    Bezerra, A. G.; Barison, A.; Oliveira, V. S.; Foti, L.; Krieger, M. A.; Dhalia, R.; Viana, I. F. T.; Schreiner, W. H.

    2012-01-01

    We report on the interaction of vanadate nanoparticles, produced using the laser ablation in liquids synthesis, with cysteine in biological molecules. Cysteine is a very important amino acid present in most proteins, but also because cysteine and the tripeptide glutathione are the main antioxidant molecules in our body system. Detailed UV–Vis absorption spectra and dynamic light scattering measurements were done to investigate the detection of cysteine in large biological molecules. The intervalence band of the optical absorption spectra shows capability for quantitative cysteine sensing in the μM range in biological macromolecules. Tests included cytoplasmic repetitive antigen and flagellar repetitive antigen proteins of the Trypanosoma cruzi protozoa, as well as the capsid p24 proteins from Human Immunodeficiency Virus type 1 and type 2. Detailed NMR measurements for hydrogen, carbon, and vanadium nuclei show that cysteine in contact with the vanadate looses hydrogen of the sulphydryl side chain, while the vanadate is reduced. The subsequent detachment of two deprotonated molecules to form cystine and the slow return to the vanadate complete the oxidation–reduction cycle. Therefore, the vanadate acts as a charge exchanging catalyst on cysteine to form cystine. The NMR results also indicate that the nanoparticles are not formed by the common orthorhombic V 2 O 5 form.

  3. Acetaldehyde Removal from Indoor Air through Chemical Absorption Using L-Cysteine

    Directory of Open Access Journals (Sweden)

    Miyuki Noguchi

    2010-09-01

    Full Text Available The irreversible removal of acetaldehyde from indoor air via a chemical reaction with amino acids was investigated. To compare effectiveness, five types of amino acid (glycine, L-lysine, L-methionine, L-cysteine, and L-cystine were used as the reactants. First, acetaldehyde-laden air was introduced into aqueous solutions of each amino acid and the removal abilities were compared. Among the five amino acids, L-cysteine solution showed much higher removal efficiency, while the other amino acids solutions didn’t show any significant differences from the removal efficiency of water used as a control. Next, as a test of the removal abilities of acetaldehyde by semi-solid L-cysteine, a gel containing L-cysteine solution was put in a fluororesin bag filled with acetaldehyde gas, and the change of acetaldehyde concentration was measured. The L-cysteine-containing gel removed 80% of the acetaldehyde in the air within 24 hours. The removal ability likely depended on the unique reaction whereby acetaldehyde and L-cysteine rapidly produce 2-methylthiazolidine-4-carboxylic acid. These results suggested that the reaction between acetaldehyde and L-cysteine has possibilities for irreversibly removing toxic acetaldehyde from indoor air.

  4. The mechanism of cysteine detection in biological media by means of vanadium oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bezerra, A. G. [Universidade Tecnologica Federal do Parana, Departamento Academico de Fisica (Brazil); Barison, A. [Universidade Federal do Parana, Departamento de Quimica (Brazil); Oliveira, V. S. [Universidade Federal do Parana, Departamento de Fisica (Brazil); Foti, L.; Krieger, M. A. [Fundacao Oswaldo Cruz, Instituto de Biologia Molecular do Parana (Brazil); Dhalia, R.; Viana, I. F. T. [Fundacao Oswaldo Cruz, Centro de Pesquisas Aggeu Magalhaes (Brazil); Schreiner, W. H., E-mail: wido@fisica.ufpr.br [Universidade Federal do Parana, Departamento de Fisica (Brazil)

    2012-09-15

    We report on the interaction of vanadate nanoparticles, produced using the laser ablation in liquids synthesis, with cysteine in biological molecules. Cysteine is a very important amino acid present in most proteins, but also because cysteine and the tripeptide glutathione are the main antioxidant molecules in our body system. Detailed UV-Vis absorption spectra and dynamic light scattering measurements were done to investigate the detection of cysteine in large biological molecules. The intervalence band of the optical absorption spectra shows capability for quantitative cysteine sensing in the {mu}M range in biological macromolecules. Tests included cytoplasmic repetitive antigen and flagellar repetitive antigen proteins of the Trypanosoma cruzi protozoa, as well as the capsid p24 proteins from Human Immunodeficiency Virus type 1 and type 2. Detailed NMR measurements for hydrogen, carbon, and vanadium nuclei show that cysteine in contact with the vanadate looses hydrogen of the sulphydryl side chain, while the vanadate is reduced. The subsequent detachment of two deprotonated molecules to form cystine and the slow return to the vanadate complete the oxidation-reduction cycle. Therefore, the vanadate acts as a charge exchanging catalyst on cysteine to form cystine. The NMR results also indicate that the nanoparticles are not formed by the common orthorhombic V{sub 2}O{sub 5} form.

  5. Sensitization by UV light of α-Al2O3:C polycrystalline detectors

    International Nuclear Information System (INIS)

    Meira B, L. C.; Rubio F, H.; Neres de A, E.; Santos, A.

    2014-08-01

    This paper describes an increase in sensitivity to gamma and beta radiation on α-Al 2 O 3 :C polycrystalline detector, which has been produced by a sol-gel process, following previous exposure to ultraviolet light. The increased sensitivity of the detector as a function of the exposure time and ultraviolet wavelength was studied. Since the main luminescent centers have emission peaks at different wavelengths, selective measurements of thermoluminescent emission intensity were done, in order to investigate the possible conversion of centers as a result of the exposition to ultraviolet light. Experimental results indicate that the nature and parameters of the luminescent centers in α-Al 2 O 3 :C sol-gel material can be very different of those in α-Al 2 O 3 :C single crystal. (author)

  6. From 2D to 3D turbulence through 2D3C configurations

    Science.gov (United States)

    Buzzicotti, Michele; Biferale, Luca; Linkmann, Moritz

    2017-11-01

    We study analytically and numerically the geometry of the nonlinear interactions and the resulting energy transfer directions of 2D3C flows. Through a set of suitably designed Direct Numerical Simulations we also study the coupling between several 2D3C flows, where we explore the transition between 2D and fully 3D turbulence. In particular, we find that the coupling of three 2D3C flows on mutually orthogonal planes subject to small-scale forcing leads to a stationary 3D out-of-equilibrium dynamics at the energy containing scales where the inverse cascade is directly balanced by a forward cascade carried by a different subsets of interactions. ERC AdG Grant No 339032 NewTURB.

  7. Study on the origin of pressure-induced superconductivity of Cs3C60

    International Nuclear Information System (INIS)

    Fujiki, S.; Kubozono, Y.; Takabayashi, Y.; Kashino, S.; Kobayashi, M.; Ishii, K.; Suematsu, H.

    2001-01-01

    Physical properties of bco phase of Cs 3+α C 60 (α=0.0-1.0) and A15 phase of Cs 3 C 60 are studied by X-ray diffraction, ESR, AC susceptibility, resistivity and Raman. The ESR of Cs 300(6) C 60 showed a broad peak of ∼380 G due to conduction electron, while no broad peak was observed in the ESR of bco Cs 3+α C 60 (α≠0.0) and A15 phase. This shows that only bco phase of Cs 3 C 60 is metallic. The AC susceptibility of bco phase of Cs 3.2(3) C 60 and Cs 3.5(1) C 60 showed no superconducting transition above 1.3 K even under high pressure, and the resistivity was 0.52 Ω cm for both samples

  8. Total synthesis of ciguatoxin CTX3C: a venture into the problems of ciguatera seafood poisoning.

    Science.gov (United States)

    Hirama, Masahiro

    2005-01-01

    After a twelve-year struggle, the total synthesis of ciguatoxin CTX3C has been achieved. Annually, more than 20,000 people worldwide suffer from ciguatera seafood poisoning. The extremely small amounts of the causative neurotoxin, ciguatoxin, in fish hampered the isolation, structural elucidation, detailed biological study, and preparation of anti-ciguatoxin antibodies for detecting these toxins. The large (3 nanometers long) and complicated molecular structure of ciguatoxins hindered chemists from completing a total synthesis. The chemical synthesis of CTX3C, determination of the absolute configuration, and synthesis-based preparation of the monoclonal antibodies as well as the effect of synthetic CTX3C on voltage-sensitive sodium channels are outlined. (c) 2005 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.

  9. Synthesis-based approach toward direct sandwich immunoassay for ciguatoxin CTX3C.

    Science.gov (United States)

    Oguri, Hiroki; Hirama, Masahiro; Tsumuraya, Takeshi; Fujii, Ikuo; Maruyama, Megumi; Uehara, Hisatoshi; Nagumo, Yoko

    2003-06-25

    Ciguatoxins are the major causative toxins of ciguatera seafood poisoning. Limited availability of ciguatoxins has hampered the development of a reliable and specific immunoassay for detecting these toxins in contaminated fish. Monoclonal antibodies (mAbs) specific against both ends of ciguatoxin CTX3C were prepared by immunization of mice with protein conjugates of rationally designed synthetic haptens, 3 and 4, in place of the natural toxin. Haptenic groups that possess a surface area larger than 400 A(2) were required to produce mAbs that can bind strongly to CTX3C itself. A direct sandwich enzyme-linked immunosorbent assay (ELISA) using these mAbs was established to detect CTX3C at the ppb level with no cross-reactivity against other related marine toxins, including brevetoxin A, brevetoxin B, okadaic acid, or maitotoxin.

  10. Expression of the C3-C 4 intermediate character in somatic hybrids between Brassica napus and the C3-C 4 species Moricandia arvensis.

    Science.gov (United States)

    O'Neill, C M; Murata, T; Morgan, C L; Mathias, R J

    1996-12-01

    The wild crucifer Moricandia arvensis is a potential source of alien genes for the genetic improvement of related Brassica crops. In particular M. arvensis has a C3-C4 intermediate photosynthetic mechanism which results in enhanced recapture of photorespired CO2 and may increase plant water-use efficiency. In order to transfer this trait into Brassica napus, somatic hybridisations were made between leaf mesophyll protoplasts from cultured M. arvensis shoot tips and hypocotyl protoplasts from three Brassica napus cultivars, 'Ariana', 'Cobra' and 'Westar'. A total of 23 plants were recovered from fusion experiments and established in the greenhouse. A wide range of chromosome numbers were observed among the regenerated plants, including some apparent mixoploids. Thirteen of the regenerated plants were identified as nuclear hybrids between B. napus and M. arvensis on the basis of isozyme analysis. The phenotypes of these hybrids were typically rather B. napus-like, but much variability was observed, including variation in flower colour, leaf shape and colour, leaf waxiness, fertility and plant vigour. CO2 compensation point measurements on the regenerated plants demonstrated that 3 of the hybrids express the M. arvensis C3-C4 intermediate character at the physiological level. Semi-thin sections through leaf tissues of these 3 plants revealed the presence of a Kranz-like leaf anatomy characteristic of M. arvensis but not found in B. napus. This is the first report of the expression of this potentially important agronomic trait, transferred from Moricandia, in M. arvensis x B. napus hybrids.

  11. Temperature driven structural-memory-effects in carbon nanotubes filled with Fe3C nano crystals

    Science.gov (United States)

    Boi, Filippo S.; Zhang, Xiaotian; Corrias, Anna

    2018-02-01

    We report the observation of novel temperature-driven structural-memory-effects in carbon nanotubes (CNTs) filled with Fe3C nano-crystals. These structural-transitions were measured by means of temperature (T) dependent x-ray diffraction (XRD) in the T-range from 298 K to 12 K. A clear reversible 2θ-shift in the 002-peak of the graphitic-CNTs-walls is found with the decrease of the temperature. As determined by Rietveld refinement, such 2θ-shift translates in a not previously reported decrease in the value of the CNT graphitic c-axis with the decrease of the temperature (from 298 K to 12 K). Also, a clear reversible 2θ-shift in the 031 and 131 diffraction-peaks of Fe3C is observed within the same T-range. Rietveld refinements confirm the existence of such memory-effect and also reveal a gradual decrease of the 010-axis of Fe3C with the decrease of the temperature. These observations imply that the observed structural-memory-effect is a characteristic of CNTs when Fe3C is the encapsulated ferromagnet. The generality of such memory-effects was further confirmed by additional measurements performed on other types of CNTs characterized by continuous Fe3C-filling. XRD measurements in the T-range from 298 K to 673 K revealed also an unusual reversible decrease of the Fe3C-peak intensities with the increase of the temperature. These observations can have important implications on the magnetic data recording applications of these nanostructures by helping in better understanding the unusual temperature-dependent magnetic instabilities of iron-based nano-crystals which have been recently reported in literature.

  12. Saturable Absorption in 2D Ti3 C2 MXene Thin Films for Passive Photonic Diodes.

    Science.gov (United States)

    Dong, Yongchang; Chertopalov, Sergii; Maleski, Kathleen; Anasori, Babak; Hu, Longyu; Bhattacharya, Sriparna; Rao, Apparao M; Gogotsi, Yury; Mochalin, Vadym N; Podila, Ramakrishna

    2018-03-01

    MXenes comprise a new class of 2D transition metal carbides, nitrides, and carbonitrides that exhibit unique light-matter interactions. Recently, 2D Ti 3 CNT x (T x represents functional groups such as OH and F) was found to exhibit nonlinear saturable absorption (SA) or increased transmittance at higher light fluences, which is useful for mode locking in fiber-based femtosecond lasers. However, the fundamental origin and thickness dependence of SA behavior in MXenes remain to be understood. 2D Ti 3 C 2 T x thin films of different thicknesses are fabricated using an interfacial film formation technique to systematically study their nonlinear optical properties. Using the open aperture Z-scan method, it is found that the SA behavior in Ti 3 C 2 T x MXene arises from plasmon-induced increase in the ground state absorption at photon energies above the threshold for free carrier oscillations. The saturation fluence and modulation depth of Ti 3 C 2 T x MXene is observed to be dependent on the film thickness. Unlike other 2D materials, Ti 3 C 2 T x is found to show higher threshold for light-induced damage with up to 50% increase in nonlinear transmittance. Lastly, building on the SA behavior of Ti 3 C 2 T x MXenes, a Ti 3 C 2 T x MXene-based photonic diode that breaks time-reversal symmetry to achieve nonreciprocal transmission of nanosecond laser pulses is demonstrated. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Transcriptome Analysis of Maize Immature Embryos Reveals the Roles of Cysteine in Improving Agrobacterium Infection Efficiency

    Science.gov (United States)

    Liu, Yan; Zhang, Zhiqiang; Fu, Junjie; Wang, Guoying; Wang, Jianhua; Liu, Yunjun

    2017-01-01

    Maize Agrobacterium-mediated transformation efficiency has been greatly improved in recent years. Antioxidants, such as, cysteine, can significantly improve maize transformation frequency through improving the Agrobacterium infection efficiency. However, the mechanism underlying the transformation improvement after cysteine exposure has not been elucidated. In this study, we showed that the addition of cysteine to the co-cultivation medium significantly increased the Agrobacterium infection efficiency of hybrid HiII and inbred line Z31 maize embryos. Reactive oxygen species contents were higher in embryos treated with cysteine than that without cysteine. We further investigated the mechanism behind cysteine-related infection efficiency increase using transcriptome analysis. The results showed that the cysteine treatment up-regulated 939 genes and down-regulated 549 genes in both Z31 and HiII. Additionally, more differentially expressed genes were found in HiII embryos than those in Z31 embryos, suggesting that HiII was more sensitive to the cysteine treatment than Z31. GO analysis showed that the up-regulated genes were mainly involved in the oxidation reduction process. The up-regulation of these genes could help maize embryos to cope with the oxidative stress stimulated by Agrobacterium infection. The down-regulated genes were mainly involved in the cell wall and membrane metabolism, such as, aquaporin and expansin genes. Decreased expression of these cell wall integrity genes could loosen the cell wall, thereby improving the entry of Agrobacterium into plant cells. This study offers insight into the role of cysteine in improving Agrobacterium-mediated transformation of maize immature embryos. PMID:29089955

  14. Negative modulation of the GABAA ρ1 receptor function by l-cysteine.

    Science.gov (United States)

    Beltrán González, Andrea N; Vicentini, Florencia; Calvo, Daniel J

    2018-01-01

    l-Cysteine is an endogenous sulfur-containing amino acid with multiple and varied roles in the central nervous system, including neuroprotection and the maintenance of the redox balance. However, it was also suggested as an excitotoxic agent implicated in the pathogenesis of neurological disorders such as Parkinson's and Alzheimer's disease. l-Cysteine can modulate the activity of ionic channels, including voltage-gated calcium channels and glutamatergic NMDA receptors, whereas its effects on GABAergic neurotransmission had not been studied before. In the present work, we analyzed the effects of l-cysteine on responses mediated by homomeric GABA A ρ1 receptors, which are known for mediating tonic γ-aminobutyric acid (GABA) responses in retinal neurons. GABA A ρ1 receptors were expressed in Xenopus laevis oocytes and GABA-evoked chloride currents recorded by two-electrode voltage-clamp in the presence or absence of l-cysteine. l-Cysteine antagonized GABA A ρ1 receptor-mediated responses; inhibition was dose-dependent, reversible, voltage independent, and susceptible to GABA concentration. Concentration-response curves for GABA were shifted to the right in the presence of l-cysteine without a substantial change in the maximal response. l-Cysteine inhibition was insensitive to chemical protection of the sulfhydryl groups of the ρ1 subunits by the irreversible alkylating agent N-ethyl maleimide. Our results suggest that redox modulation is not involved during l-cysteine actions and that l-cysteine might be acting as a competitive antagonist of the GABA A ρ1 receptors. © 2017 International Society for Neurochemistry.

  15. Identification of nasopharyngeal carcinoma from photoluminescence spectra of 3C-SiC nanocrystals

    Science.gov (United States)

    Wang, Li-Fen; Guo, Jun-Hong; Huang, Zhi-Chun; Gu, Jian-Sen; Feng, Li-Ren; Liu, Li-Zhe

    2017-09-01

    The identification of intracellular pH (pHi) during carcinogenesis progression plays a crucial role in the studies of biochemistry, cytology, and clinical medicine. In this work, 3C-SiC nanocrystals (NCs), which can effectively monitor the pH environment by using the linear relation between photoluminescence intensity and surface OH- and H+ concentration, are adapted as fluorescent probes for monitoring carcinogenesis progression of nasopharyngeal carcinoma. Our results demonstrated that 3C-SiC NCs are compatible with living cells and have low cytotoxicity. The pHi measurements in different carcinogenesis environments indicate the validity and sensitivity of this technology in identifying nasopharyngeal carcinoma in application.

  16. Model Research On Synthesis Of Al2O3-C Layers By MOCVD

    Directory of Open Access Journals (Sweden)

    Sawka A.

    2015-06-01

    Full Text Available These are model studies whose aim is to obtain information that would allow development of new technology for synthesizing monolayers of Al2O3-C with adjusted microstructure on cemented carbides. The Al2O3-C layer will constitute an intermediate layer on which the outer layer of Al2O3 without carbon is synthesized. The purpose of the intermediate layer is to block the cobalt diffusion to the synthesized outer layer of Al2O3 and to stop the diffusion of air oxygen to the substrate during the synthesis of the outer layer. This layer should be thin, continuous, dense and uniform in thickness.

  17. Preparation, crystallization and X-ray diffraction analysis to 1.5 Å resolution of rat cysteine dioxygenase, a mononuclear iron enzyme responsible for cysteine thiol oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Chad R. [Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853-8001 (United States); Hao, Quan [MacCHESS at the Cornell High Energy Synchrotron Source, Cornell University, Ithaca, NY 14853-8001 (United States); Stipanuk, Martha H., E-mail: mhs6@cornell.edu [Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853-8001 (United States)

    2005-11-01

    Recombinant rat cysteine dioxygenase (CDO) has been expressed, purified and crystallized and X-ray diffraction data have been collected to 1.5 Å resolution. Cysteine dioxygenase (CDO; EC 1.13.11.20) is an ∼23 kDa non-heme iron metalloenzyme that is responsible for the oxidation of cysteine by O{sub 2}, yielding cysteinesulfinate. CDO catalyzes the first step in the conversion of cysteine to taurine, as well as the first step in the catabolism of cysteine to pyruvate plus sulfate. Recombinant rat CDO was heterologously expressed, purified and crystallized. The protein was expressed as a fusion protein bearing a polyhistidine tag to facilitate purification, a thioredoxin tag to improve solubility and a factor Xa cleavage site to permit removal of the entire N-terminus, leaving only the 200 amino acids inherent to the native protein. A multi-step purification scheme was used to achieve >95% purity of CDO. The optimal CDO crystals diffracted to 1.5 Å resolution and belonged to space group P4{sub 3}2{sub 1}2 or P4{sub 1}2{sub 1}2, with unit-cell parameters a = b = 57.55, c = 123.06 Å, α = β = γ = 90°. CDO shows little homology to any other proteins; therefore, the structure of the enzyme will be determined by ab initio phasing using a selenomethionyl derivative.

  18. Dynamics of postirradiation intracellular cysteine and aspartic proteinases profiles in proliferating and nonproliferating mammalian cells

    International Nuclear Information System (INIS)

    Korbelik, M.; Osmak, M.; Suhar, A.; Turk, V.; Skrk, J.

    1990-01-01

    Dynamics of postirradiation intracellular cysteine and aspartic proteinases profiles were examined in proliferating and nonproliferating Chinese hamster fibroblasts (V 79). The results show that there are significant alterations in cysteine and aspartic intracellular proteinases activity already in the early postirradiation period, which are different in proliferating and nonproliferating cells. Irradiation of the cells examined to low doses and up to 15 Gy induced an increase in cysteine proteinases activity in the early postexposure period, while at higher irradiation doses applied, the activity of these proteinases was decreased. These observations suggest that intracellular proteinases are actively participating in process involving recovery from radiation injury or cell killing. (orig.) [de

  19. Adsorption Dynamics and Self-Assembled L-cysteine on Au(100)

    DEFF Research Database (Denmark)

    Engelbrekt, Christian; Nazmutdinov, Renat R.; Yan, Jiawei

    As the only amino acid with a functional thiol group, L - cysteine offers a strong perspective both for binding to gold and other metals, and for gentle immobilization of biomolecules. Binding to single - crystal, atomically planar surfaces offers the additional perspective that bound L - cysteine...... can be structurally mapped at the single - molecule level . In this work, we have followed the adsorption of L - cysteine on single - crystal Au(100) by measuring the electrode potential dynamics during the adsorption process. In situ STM revealed the structure of the self - assembled ordered layers...

  20. E.S.R. studies of mechanisms of radiation protection effect by cysteine and cystine

    International Nuclear Information System (INIS)

    Xue-Peng, L.; Tie-Cheng, T.; Nian-Yun, L.

    1981-01-01

    By means of E.S.R. the repair mechanism of radiation induced spin transfer from dTMP to cysteine in binary system dTMP-cysteine has been confirmed. Furthermore, a new marked radiation protection effect, exerted by cysteine or cystine on thymine irradiated and observed at low temperature, has been detected. Another sort of fast protection mechanism, including electron transfer and excitation transfer, has been proposed, based on recent advances of primary radiation process of pyrimidine bases and analysed by molecular orbital theory. This fast radiation protection mechanism provides the possibility to utilize electrophilic sulfhydryl protectors for realizing excellent protection effect. (author)

  1. Interaction of cysteine and copper ions on the surface of iron: EIS, polarization and XPS study

    International Nuclear Information System (INIS)

    El-Deab, Mohamed S.

    2011-01-01

    Highlights: → The current study demonstrates a comprehensive study for Cysteine + Cu(II) ions as an efficient inhibitor as demonstrated by EIS, XPS and potentiodynamic polarization measurements, in addition to traditional weight loss measurements. → The novelty of the current work originates from the combined use of an eco-friendly compound (i.e., cysteine) with a minute amount of copper ions (in the micro molar range) as a corrosion inhibitor for low carbon steel in acidic medium. To this end, cysteine shows only moderate inhibition ca. 60% for iron which jumps up to more than 95% in the presence of micro molar range of Cu(II) ions. → Cysteine-Cu(II) blends are found superior to benzotriazole (BTAH)-Cu(II) blends in terms of their long-term stability in addition to the avoidance of the use of the well-reported highly toxic BTAH. - Abstract: This study addresses the enhancing effect of copper ions on the inhibition efficiency (IE) of cysteine (an eco-friendly compound) against the corrosion of iron in 0.5 M sulphuric acid. Electrochemical impedance spectroscopy (EIS) data revealed a significant increase in the polarization resistance (R p ) of the iron/solution interface in the presence of cysteine and Cu(II) ions instead of cysteine alone. That is, IE of 95% is obtained in the presence of 5 mM cysteine and 25 μM Cu(II) ions, compared to 66% in absence of Cu(II) ions. Moreover, electrochemical polarization measurements indicate that cysteine and Cu(II) ions blends act as mixed-type inhibitors for the corrosion of iron. The formation of Cu(I)-cysteinate complex and/or cysteine SAM at Cu atop the iron surface (as evident from X-ray photoelectron spectroscopy (XPS)) blocks the underlying iron surface and imparts a pronounced protection against its corrosion. IE of cysteine-Cu(II) blend remains effectively unchanged with immersion time indicating its high stability in the used acidic medium.

  2. Oral Administration of (S)-Allyl-l-Cysteine and Aged Garlic Extract to Rats: Determination of Metabolites and Their Pharmacokinetics.

    Science.gov (United States)

    Park, Taehoon; Oh, Ju-Hee; Lee, Joo Hyun; Park, Sang Cheol; Jang, Young Pyo; Lee, Young-Joo

    2017-11-01

    ( S )-Allyl-l-cysteine is the major bioactive compound in garlic. ( S )-Allyl-l-cysteine is metabolized to ( S )-allyl-l-cysteine sulfoxide, N -acetyl-( S )-allyl-l-cysteine, and N -acetyl-( S )-allyl-l-cysteine sulfoxide after oral administration. An accurate LC-MS/MS method was developed and validated for the simultaneous quantification of ( S )-allyl-l-cysteine and its metabolites in rat plasma, and the feasibility of using it in pharmacokinetic studies was tested. The analytes were quantified by multiple reaction monitoring using an atmospheric pressure ionization mass spectrometer. Because significant quantitative interference was observed between ( S )-allyl-l-cysteine and N -acetyl-( S )-allyl-l-cysteine as a result of the decomposition of N -acetyl-( S )-allyl-l-cysteine at the detector source, chromatographic separation was required to discriminate ( S )-allyl-l-cysteine and its metabolites on a reversed-phase C 18 analytical column with a gradient mobile phase consisting of 0.1% formic acid and acetonitrile. The calibration curves of ( S )-allyl-l-cysteine, ( S )-allyl-l-cysteine sulfoxide, N -acetyl-( S )-allyl-l-cysteine, and N -acetyl-( S )-allyl-l-cysteine sulfoxide were linear over each concentration range, and the lower limits of quantification were 0.1 µg/mL [( S )-allyl-l-cysteine and N -acetyl-( S )-allyl-l-cysteine] and 0.25 µg/mL [( S )-allyl-l-cysteine sulfoxide and N -acetyl-( S )-allyl-l-cysteine sulfoxide]. Acceptable intraday and inter-day precisions and accuracies were obtained at three concentration levels. The method satisfied the regulatory requirements for matrix effects, recovery, and stability. The validated LC-MS/MS method was successfully used to determine the concentration of ( S )-allyl-l-cysteine and its metabolites in rat plasma samples after the administration of ( S )-allyl-l-cysteine or aged garlic extract. Georg Thieme Verlag KG Stuttgart · New York.

  3. Towards IoT platforms’ integration : Semantic Translations between W3C SSN and ETSI SAREF

    NARCIS (Netherlands)

    Moreira, João Luiz; Daniele, L.M.; Ferreira Pires, Luis; van Sinderen, Marten J.; Wasielewska, Katarzyna; Szmeja, Pawel; Pawlowski, Wieslaw; Ganzha, Maria; Paprzycki, Marcin

    2017-01-01

    Several IoT ontologies have been developed lately to improve the semantic interoperability of IoT solutions. The most popular of these ontologies, the W3C Semantic Sensor Network (SSN), is considered an ontological foundation for diverse IoT initiatives, particularly OpenIoT. With characteristics

  4. Lowest instrumented vertebra selection in Lenke 3C and 6C scoliosis

    DEFF Research Database (Denmark)

    Wang, Yu; Bünger, Cody; Zhang, Yanqun

    2012-01-01

    PURPOSE: The aim of this study was to investigate whether or not post-op curve behaviour differs due to different choices of lowest instrumented vertebra (LIV) with reference to lumbar apical vertebra (LAV) in Lenke 3C and 6C scoliosis. METHODS: We reviewed all the AIS cases surgically treated...... it can yield similar correction while preserving more lumbar mobility and growth potential....

  5. New Ti3C2 aerogel as promising negative electrode materials for asymmetric supercapacitors

    Science.gov (United States)

    Li, Lu; Zhang, Mingyi; Zhang, Xitian; Zhang, Zhiguo

    2017-10-01

    Novel 3D Ti3C2 aerogel has been first synthesized by a simple EDA-assisted self-assembly process. Its inside are channels and pores structure. The interconnected aerogel structure could efficiently restrain restacking of Ti3C2 flakes. Thus, it exhibits a large specific surface area as high as 176.3 m2 g-1. The electrochemical performances have been measured. The Ti3C2 aerogel achieves a quite high areal capacitance of 1012.5 mF cm-2 for the mass loading of 15 mg at a scan rate of 2 mV s-1 in 1 M KOH electrolyte. An asymmetric supercapacitor (ASC) has been assembled by using the Ti3C2 aerogel electrode as the negative electrode and electrospinning carbon nanofiber film as the positive electrode. The device can deliver a high energy density of 120.0 μWh cm-2 and a maximum power density of 26123 μW cm-2. A lamp panel with nineteen red light-emitting diodes has been powered by two ASCs in series.

  6. Type 3c (pancreatogenic) diabetes mellitus secondary to chronic pancreatitis and pancreatic cancer.

    Science.gov (United States)

    Hart, Phil A; Bellin, Melena D; Andersen, Dana K; Bradley, David; Cruz-Monserrate, Zobeida; Forsmark, Christopher E; Goodarzi, Mark O; Habtezion, Aida; Korc, Murray; Kudva, Yogish C; Pandol, Stephen J; Yadav, Dhiraj; Chari, Suresh T

    2016-11-01

    Diabetes mellitus is a group of diseases defined by persistent hyperglycaemia. Type 2 diabetes, the most prevalent form, is characterised initially by impaired insulin sensitivity and subsequently by an inadequate compensatory insulin response. Diabetes can also develop as a direct consequence of other diseases, including diseases of the exocrine pancreas. Historically, diabetes due to diseases of the exocrine pancreas was described as pancreatogenic or pancreatogenous diabetes mellitus, but recent literature refers to it as type 3c diabetes. It is important to note that type 3c diabetes is not a single entity; it occurs because of a variety of exocrine pancreatic diseases with varying mechanisms of hyperglycaemia. The most commonly identified causes of type 3c diabetes are chronic pancreatitis, pancreatic ductal adenocarcinoma, haemochromatosis, cystic fibrosis, and previous pancreatic surgery. In this Review, we discuss the epidemiology, pathogenesis, and clinical relevance of type 3c diabetes secondary to chronic pancreatitis and pancreatic ductal adenocarcinoma, and highlight several important knowledge gaps. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. A thin layer fiber-coupled luminescence dosimeter based on Al2O3:C

    DEFF Research Database (Denmark)

    Klein, F.A.; Greilich, Steffen; Andersen, Claus Erik

    2011-01-01

    In this paper we present a fiber-coupled luminescent Al2O3:C dosimeter probe with high spatial resolution (0.1 mm). It is based on thin layers of Al2O3:C crystal powder and a UV-cured acrylate monomer composition. The fabrication of the thin layers is described in detail. No influence of the intr......In this paper we present a fiber-coupled luminescent Al2O3:C dosimeter probe with high spatial resolution (0.1 mm). It is based on thin layers of Al2O3:C crystal powder and a UV-cured acrylate monomer composition. The fabrication of the thin layers is described in detail. No influence...... of the introduced polymer host matrix on the dosimetric properties was observed. Depth-dose measurements with the new detectors in a 142.66 MeV proton and 270.55 MeV/u carbon ion beam are presented as example applications. We used an RL protocol with saturated crystals allowing for time-effective measurements...... without sensitivity corrections. For protons, a relative luminescence efficiency hHCP of 0.715 0.014 was found in the Bragg peak. For carbon ions, a value of 0.498 0.001 was found in the entrance channel, 0.205 0.015 in the Bragg peak, and a mean of 0.413 0.050 in the tail region. The mean range...

  8. CVD growth and characterization of 3C-SiC thin films

    Indian Academy of Sciences (India)

    Unknown

    Cubic silicon carbide (3C-SiC) thin films were grown on (100) and (111) Si substrates by CVD technique using ... of grown films were studied using optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis and X-ray ... the oxide mask gets damaged (Edgar et al 1998). There- fore, lower ...

  9. Ratcheting rotation or speedy spinning: EPR and dynamics of Sc3C2@C80

    Czech Academy of Sciences Publication Activity Database

    Roukala, J.; Straka, Michal; Taubert, S.; Vaara, J.; Lantto, P.

    2017-01-01

    Roč. 53, č. 64 (2017), s. 8992-8995 ISSN 1359-7345 R&D Projects: GA ČR(CZ) GA17-07091S Institutional support: RVO:61388963 Keywords : endohedral metallofullerene * contrast agents * Sc3@C82 Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 6.319, year: 2016

  10. Rapid synthesis of the A-E fragment of ciguatoxin CTX3C.

    Science.gov (United States)

    Clark, J Stephen; Conroy, Joanne; Blake, Alexander J

    2007-05-24

    The A-E fragment of the marine natural product CTX3C has been prepared in an efficient manner by using a strategy in which two-directional and iterative ring-closing metathesis (RCM) reactions were employed for ring construction.

  11. Synthetic ciguatoxin CTX 3C induces a rapid imbalance in neuronal excitability.

    Science.gov (United States)

    Martín, Victor; Vale, Carmen; Hirama, Masahiro; Yamashita, Shuji; Rubiolo, Juan Andrés; Vieytes, Mercedes R; Botana, Luis M

    2015-06-15

    Ciguatera is a human global disease caused by the consumption of contaminated fish that have accumulated ciguatoxins (CTXs), sodium channel activator toxins. Symptoms of ciguatera include neurological alterations such as paraesthesiae, dysaesthesiae, depression, and heightened nociperception, among others. An important issue to understand these long-term neurological alterations is to establish the role that changes in activity produced by CTX 3C represent to neurons. Here, the effects of synthetic ciguatoxin CTX 3C on membrane potential, spontaneous spiking, and properties of synaptic transmission in cultured cortical neurons of 11-18 days in vitro (DIV) were evaluated using electrophysiological approaches. CTX 3C induced a large depolarization that decreased neuronal firing and caused a rapid inward tonic current that was primarily GABAergic. Moreover, the toxin enhanced the amplitude of miniature postsynaptic inhibitory currents (mIPSCs), whereas it decreased the amplitude of miniature postsynaptic excitatory currents (mEPSCs). The frequency of mIPSCs increased, whereas the frequency of mEPSCs remained unaltered. We describe, for the first time, that a rapid membrane depolarization caused by CTX 3C in cortical neurons activates mechanisms that tend to suppress electrical activity by shifting the balance between excitatory and inhibitory synaptic transmission toward inhibition. Indeed, these results suggest that the acute effects of CTX on synaptic transmission could underlie some of the neurological symptoms caused by ciguatera in humans.

  12. Convergent synthesis of the HIJKLM ring system of ciguatoxin CTX3C.

    Science.gov (United States)

    Takamura, Hiroyoshi; Nishiuma, Naoki; Abe, Takashi; Kadota, Isao

    2011-09-02

    The HIJKLM ring system of ciguatoxin CTX3C was synthesized in a convergent manner. The key steps were a conjugate addition/alkylation sequence, spiroacetalization, intramolecular allylation, ring-closing metathesis, and hydrogenation to form the 36-α-methyl substituent.

  13. A short-time fading study of Al2O3:C

    International Nuclear Information System (INIS)

    Nascimento, L.F.; Vanhavere, F.; Silva, E.H.; Deene, Y. De

    2015-01-01

    This paper studies the short-time fading from Al 2 O 3 :C by measuring optically stimulated luminescence (OSL) signals (Total OSL: T OSL , and Peak OSL: P OSL ) from droplets and Luxel™ pellets. The influence of various bleaching regimes (blue, green and white) and light power is compared. The fading effect is the decay of the OSL signal in the dark at room temperature. Al 2 O 3 :C detectors were submitted to various bleaching regimes, irradiated with a reference dose and read out after different time spans. Investigations were carried out using 2 mm size droplet detectors, made of thin Al 2 O 3 :C powder mixed with a photocured polymer. Tests were compared to Luxel™-type detectors (Landauer Inc.). Short-time post-irradiation fading is present in OSL results (T OSL and P OSL ) droplets for time spans up to 200 s. The effect of short-time fading can be lowered/removed when treating the detectors with high-power and/or long time bleaching regimes; this result was observed in both T OSL and P OSL from droplets and Luxel™. - Highlights: • Droplet composed of thin powder of Al 2 O 3 :C was prepared using a photo-curable polymer. • Powder grain sizes ranged from 5 μm to 35 μm. • Short-time fading was measured for irradiated samples. • Various bleaching regimes and light power was tested. • Droplets were compared to a commercially dosimeter, Luxel™

  14. The Multi-component X-ray Emission of 3C 273

    Science.gov (United States)

    Soldi, S.; Türler, M.; Paltani, S.; Courvoisier, T. J.-L.

    2009-05-01

    3C 273 is the brightest quasar in the sky and among the most extensively observed and studied AGN, therefore one of the most suitable targets for a long-term, multi-frequency study. The superposition of a thermal Comptonisation component, similar to that observed in Seyfert galaxies, and of a non-thermal component, related to the jet emission, seems to explain some of the spectral and timing properties of the X-ray emission of 3C 273. Yet, during some observations this dichotomy has not been observed and the variability properties could also be consistent with a single-component scenario, characterised by two parameters varying independently. In order to understand the nature of the X-ray emission in 3C 273, a series of observations up to 80-100 keV, possibly catching the source in different flux states, are essential. Simbol-X will be able to study the emission of 3C 273 in the broad 0.5-80 keV band with high sensitivity, allowing us to disentangle the emission from different spectral components, with 20-30 ks long observations. In addition, the shape and the origin of the high-energy emission of this quasar will be further constrained thanks to the AGILE and Fermi satellites, monitoring the γ-ray sky in the MeV-GeV energy domain.

  15. Simultaneous observations of the quasar 3C 273 with INTEGRAL, XMM-Newton and RXTE

    DEFF Research Database (Denmark)

    Courvoisier, T.J.L.; Beckmann, V.; Bourban, G.

    2003-01-01

    INTEGRAL has observed the bright quasar 3C 273 on 3 epochs in January 2003 as one of the first observations of the open programme. The observation on January 5 was simultaneous with RXTE and XMM-Newton observations. We present here a first analysis of the continuum emission as observed by these 3...

  16. A DEEP XMM-NEWTON OBSERVATION OF THE QUASAR 3C 287

    International Nuclear Information System (INIS)

    Salvesen, G.; Miller, J. M.; Cackett, E.; Siemiginowska, A.

    2009-01-01

    We report on an XMM-Newton observation of the z = 1.055 quasar and Gigahertz Peaked Spectrum (GPS) source 3C 287. Our 62.3 ks observation provides an exceptional X-ray view of a prominent member of this important subclass of active galactic nuclei (AGNs). The X-ray spectra of 3C 287 are consistent with a simple absorbed power law with a spectral index of Γ = 1.72 ± 0.02. Our fits imply a bolometric luminosity of L = 5.8 ± 0.2 x 10 45 erg s -1 over the 0.3-10.0 keV band; this gives a mass lower limit of M BHmin ≥ 4.6 x 10 7 M sun assuming X-rays contribute 10% of the bolometric luminosity and radiation at the Eddington limit. Iron emission lines are common in the X-ray spectra of many AGNs, but the observed spectra appear to rule out strong emission lines in 3C 287. The simple power-law spectrum and the absence of strong emission lines may support a picture where our line of sight intersects a relativistic jet. Milliarcsecond radio imaging of 3C 287 appears to support this interpretation. We discuss our results in the context of different AGNs subclasses and the possibility that GPS sources harbor newly formed black hole jets.

  17. Creep properties of simulated heat-affected zone of HR3C austenitic steel

    Czech Academy of Sciences Publication Activity Database

    Sklenička, Václav; Kuchařová, Květa; Kvapilová, Marie; Svoboda, Milan; Král, Petr; Dvořák, Jiří

    2017-01-01

    Roč. 128, JUN (2017), s. 238-247 ISSN 1044-5803 R&D Projects: GA MŠk(CZ) LQ1601 Institutional support: RVO:68081723 Keywords : HR3C steel * Welding * Heat affected zone * Creep * Microstructure * Fractography Subject RIV: JG - Metallurgy OBOR OECD: Materials engineering Impact factor: 2.714, year: 2016

  18. Thermally stimulated conductivity and thermoluminescence from Al2O3 : C

    DEFF Research Database (Denmark)

    Agersnap Larsen, N.; Bøtter-Jensen, L.; McKeever, S.W.S.

    1999-01-01

    Simultaneous measurements of thermoluminescence (TL) and thermally stimulated conductivity (TSC) are reported on single-crystal dosimetry-quality Al2O3:C following gamma irradiation at room temperature. Analysis of the data reveals a superposition of several first-order TL and TSC peaks caused...

  19. X-ray Emission from the Radio Jet in 3C 120

    DEFF Research Database (Denmark)

    Harris, D. E.; Hjorth, J.; Sadun, A. C.

    1999-01-01

    We report the discovery of X-ray emission from a radio knot at a projected distance of 25" from the nucleus of the Seyfert galaxy, 3C 120. The data were obtained with the ROSAT High Resolution Imager (HRI). Optical upper limits for the knot preclude a simple power law extension of the radio...

  20. Pressure dependence of the superconducting transition temperature of Rb3C60 up to 20 kbar

    International Nuclear Information System (INIS)

    Bud'ko, S.L.; Meng, R.L.; Chu, C.W.; Hor, P.H.

    1991-01-01

    AC susceptibility measurements of Rb 3 C 60 under hydrostatic pressure up to 20 kbar are reported. The superconducting transition temperature (T c ) decreases linearly under pressure with the pressure derivative dT c /dP = -0.78 K degrees/kbar

  1. Radioluminescence in Al2O3: C - analytical and numerical simulation results

    DEFF Research Database (Denmark)

    Pagonis, V.; Lawless, J.; Chen, R.

    2009-01-01

    The phenomenon of radioluminescence (RL) has been reported in a number of materials including Al2O3 : C, which is one of the main dosimetric materials. In this work, we study RL using a kinetic model involving two trapping states and two kinds of recombination centres. The model has been previous...

  2. Optical conductivity in A3C60 (A=K, Rb)

    NARCIS (Netherlands)

    Brink, J. van den; Gunnarsson, O.; Eyert, V.

    1997-01-01

    Published in: Phys. Rev. B 57 (1998) 2163-2167 Citing articles (CrossRef) citations recorded in [Science Citation Index] Abstract: We study the optical conductivity in A3C60 (A =K, Rb). The effects of the electron-phonon interaction is included to lowest order in the coupling strength lambda. It is

  3. The corona of the broad-line radio galaxy 3C 390.3

    DEFF Research Database (Denmark)

    Lohfink, A. M.; Ogle, P.; Tombesi, F.

    2015-01-01

    We present the results from a joint Suzaku/NuSTAR broadband spectral analysis of 3C 390.3. The high quality data enables us to clearly separate the primary continuum from the reprocessed components allowing us to detect a high energy spectral cut-off (Ecut= 117-14+18 keV), and to place constraint...

  4. Fiber-coupled Al_2O_3:C radioluminescence dosimetry for total body irradiations

    International Nuclear Information System (INIS)

    Buranurak, S.; Andersen, C.E.

    2016-01-01

    In vivo dosimetry can be important and relevant in radiotherapy, especially when commissioning new treatment techniques at hospitals. This study investigates the potential use of fiber-coupled radioluminescence (RL) dosimetry based on Al_2O_3:C or organic plastic scintillators for this purpose in the context of Total Body Irradiations (TBIs) where patients are treated with large fields of 6 or 18 MV photons at an extended source-to-surface distance (SSD). The study shows that Al_2O_3:C dosimetry using the saturated-RL protocol may be suitable for real-time in vivo dosimetry during TBI treatments from the perspective of the good agreement with alanine dosimetry and other critical phantom tests, including the ability to cope with the large stem signal experienced during TBI treatments at extended SSD. In contrast, the chromatic stem removal technique often used for organic plastic scintillators did not work well in large fields with the tested calibration procedure and instrumentation. An apparent dose-rate effect discussed in a previous study of the RL properties of Al_2O_3:C (Andersen et al., 2011) was found to have resulted from an overlooked dead time problem in the counting system, and this potential caveat can therefore be removed from the list of potential problems associated with fiber-coupled Al_2O_3:C dosimetry using the saturated-RL protocol. This further has implications for TBI dosimetry using the RL Al_2O_3:C system due to large dose-rate differences between calibrations at the iso-center and in vivo measurements at extended source-to-surface distances. - Highlights: • Fiber-coupled dosimetry can be used for measurements during total body irradiations. • An apparent dose-effect associated with radioluminescence from Al2O3:C was resolved. • The gated-counting stem removal procedure worked well for Al2O3:C in pulsed accelerator beams. • The chromatic stem removal procedure did not work well with the tested instrumentation and organic plastic

  5. Cytokine expression in patients with bladder pain syndrome/interstitial cystitis ESSIC type 3C.

    Science.gov (United States)

    Logadottir, Yr; Delbro, Dick; Fall, Magnus; Gjertsson, Inger; Jirholt, Pernilla; Lindholm, Catharina; Peeker, Ralph

    2014-11-01

    Bladder wall nitric oxide production in patients with bladder pain syndrome type 3C is increased compared to undetectable nitric oxide in patients with nonHunner bladder pain syndrome and healthy controls. However, the underlying mechanism/s of the increased nitric oxide production is largely unknown. We compared mRNA expression of a select group of cytokines in patients with bladder pain syndrome/interstitial cystitis type 3C and in pain-free controls. Cold cup biopsies from 7 patients with bladder pain syndrome type 3C and 6 healthy subjects were analyzed. mRNA expression of IL-4, 6, 10 and 17A, iNOS, TNF-α, TGF-β and IFN-γ was estimated by real-time polymerase chain reaction. IL-17 protein expression was determined by immunohistochemistry. Mast cells were labeled with tryptase to evaluate cell appearance and count. IL-6, 10 and 17A, and iNOS mRNA levels as well as the number of mast cells infiltrating the bladder mucosa were significantly increased in patients with bladder pain syndrome type 3C compared to healthy controls. TNF-α, TGF-β and IFN-γ mRNA levels were similar in patients and controls. IL-17A expression at the protein level was up-regulated and localized to inflammatory cells and urothelium in patients with bladder pain syndrome type 3C. Patients with bladder pain syndrome/interstitial cystitis had increased mRNA levels of IL-17A, 10 and 6, and iNOS. IL-17A might be important in the inflammatory process. To our knowledge the increase in IL-17A is a novel finding that may have new treatment implications. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  6. Light-Driven Au-WO3@C Janus Micromotors for Rapid Photodegradation of Dye Pollutants.

    Science.gov (United States)

    Zhang, Qilu; Dong, Renfeng; Wu, Yefei; Gao, Wei; He, Zihan; Ren, Biye

    2017-02-08

    A novel light-driven Au-WO 3 @C Janus micromotor based on colloidal carbon WO 3 nanoparticle composite spheres (WO 3 @C) prepared by one-step hydrothermal treatment is described. The Janus micromotors can move in aqueous media at a speed of 16 μm/s under 40 mW/cm 2 UV light due to diffusiophoretic effects. The propulsion of such Au-WO 3 @C Janus micromotors (diameter ∼ 1.0 μm) can be generated by UV light in pure water without any external chemical fuels and readily modulated by light intensity. After depositing a paramagnetic Ni layer between the Au layer and WO 3 , the motion direction of the micromotor can be precisely controlled by an external magnetic field. Such magnetic micromotors not only facilitate recycling of motors but also promise more possibility of practical applications in the future. Moreover, the Au-WO 3 @C Janus micromotors show high sensitivity toward extremely low concentrations of sodium-2,6-dichloroindophenol (DCIP) and Rhodamine B (RhB). The moving speed of motors can be significantly accelerated to 26 and 29 μm/s in 5 × 10 -4 wt % DCIP and 5 × 10 -7 wt % RhB aqueous solutions, respectively, due to the enhanced diffusiophoretic effect, which results from the rapid photocatalytic degradation of DCIP and RhB by WO 3 . This photocatalytic acceleration of the Au-WO 3 @C Janus micromotors confirms the self-diffusiophoretic mechanism and opens an opportunity to tune the motility of the motors. This work also offers the light-driven micromotors a considerable potential for detection and rapid photodegradation of dye pollutants in water.

  7. The unique cysteine knot regulates the pleotropic hormone leptin.

    Directory of Open Access Journals (Sweden)

    Ellinor Haglund

    Full Text Available Leptin plays a key role in regulating energy intake/expenditure, metabolism and hypertension. It folds into a four-helix bundle that binds to the extracellular receptor to initiate signaling. Our work on leptin revealed a hidden complexity in the formation of a previously un-described, cysteine-knotted topology in leptin. We hypothesized that this unique topology could offer new mechanisms in regulating the protein activity. A combination of in silico simulation and in vitro experiments was used to probe the role of the knotted topology introduced by the disulphide-bridge on leptin folding and function. Our results surprisingly show that the free energy landscape is conserved between knotted and unknotted protein, however the additional complexity added by the knot formation is structurally important. Native state analyses led to the discovery that the disulphide-bond plays an important role in receptor binding and thus mediate biological activity by local motions on distal receptor-binding sites, far removed from the disulphide-bridge. Thus, the disulphide-bridge appears to function as a point of tension that allows dissipation of stress at a distance in leptin.

  8. Cysteine-independent activation/inhibition of heme oxygenase-2

    Directory of Open Access Journals (Sweden)

    Dragic Vukomanovic

    2016-01-01

    Full Text Available Reactive thiols of cysteine (cys residues in proteins play a key role in transforming chemical reactivity into a biological response. The heme oxygenase-2 (HO-2 isozyme contains two cys residues that have been implicated in binding of heme and also the regulation of its activity. In this paper, we address the question of a role for cys residues for the HO-2 inhibitors or activators designed in our laboratory. We tested the activity of full length recombinant human heme oxygenase-2 (FL-hHO-2 and its analog in which cys265 and cys282 were both replaced by alanine to determine the effect on activation by menadione (MD and inhibition by QC-2350. Similar inhibition by QC-2350 and almost identical activation by MD was observed for both recombinant FL-hHO-2s. Our findings are interpreted to mean that thiols of FL-hHO-2s are not involved in HO-2 activation or inhibition by the compounds that have been designed and identified by us. Activation or inhibition of HO-2 by our compounds should be attributed to a mechanism other than altering binding affinity of HO-2 for heme through cys265 and cys282.

  9. Mutation choice to eliminate buried free cysteines in protein therapeutics.

    Science.gov (United States)

    Xia, Xue; Longo, Liam M; Blaber, Michael

    2015-02-01

    Buried free-cysteine (Cys) residues can contribute to an irreversible unfolding pathway that promotes protein aggregation, increases immunogenic potential, and significantly reduces protein functional half-life. Consequently, mutation of buried free-Cys residues can result in significant improvement in the storage, reconstitution, and pharmacokinetic properties of protein-based therapeutics. Mutational design to eliminate buried free-Cys residues typically follows one of two common heuristics: either substitution by Ser (polar and isosteric), or substitution by Ala or Val (hydrophobic); however, a detailed structural and thermodynamic understanding of Cys mutations is lacking. We report a comprehensive structure and stability study of Ala, Ser, Thr, and Val mutations at each of the three buried free-Cys positions (Cys16, Cys83, and Cys117) in fibroblast growth factor-1. Mutation was almost universally destabilizing, indicating a general optimization for the wild-type Cys, including van der Waals and H-bond interactions. Structural response to Cys mutation characteristically involved changes to maintain, or effectively substitute, local H-bond interactions-by either structural collapse to accommodate the smaller oxygen radius of Ser/Thr, or conversely, expansion to enable inclusion of novel H-bonding solvent. Despite the diverse structural effects, the least destabilizing average substitution at each position was Ala, and not isosteric Ser. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  10. Plasma Total Cysteine and Cardiovascular Risk Burden: Action and Interaction

    Directory of Open Access Journals (Sweden)

    Benedetta De Chiara

    2012-01-01

    Full Text Available We hypothesized that redox analysis could provide sensitive markers of the oxidative pathway associated to the presence of an increasing number of cardiovascular risk factors (RFs, independently of type. We classified 304 subjects without cardiovascular disease into 4 groups according to the total number of RFs (smoking, hypertension, hypercholesterolaemia, hyperhomocysteinaemia, diabetes, obesity, and their combination. Oxidative stress was evaluated by measuring plasma total and reduced homocysteine, cysteine (Cys, glutathione, cysteinylglycine, blood reduced glutathione, and malondialdehyde. Twenty-seven percent of subjects were in group 0 RF, 26% in 1 RF, 31% in 2 RF, and 16% in ≥3 RF. By multivariable ordinal regression analysis, plasma total Cys was associated to a higher number of RF (OR = 1.068; 95% CI = 1.027–1.110, =0.002. Total RF burden is associated with increased total Cys levels. These findings support a prooxidant effect of Cys in conjunction with RF burden, and shed light on the pathophysiologic role of redox state unbalance in preclinical atherosclerosis.

  11. Peptidomic Identification of Cysteine-Rich Peptides from Plants.

    Science.gov (United States)

    Hemu, Xinya; Serra, Aida; Darwis, Dina A; Cornvik, Tobias; Sze, Siu Kwan; Tam, James P

    2018-01-01

    Plant cysteine-rich peptides (CRPs) constitute a majority of plant-derived peptides with high molecular diversity. This protocol describes a rapid and efficient peptidomic approach to identify a whole spectrum of CRPs in a plant extract and decipher their molecular diversity and bioprocessing mechanism. Cyclotides from C. ternatea are used as the model CRPs to demonstrate our methodology. Cyclotides exist naturally in both cyclic and linear forms, although the linear forms (acyclotide) are generally present at much lower concentrations. Both cyclotides and acyclotides require linearization of their backbone prior to fragmentation and sequencing. A novel and practical three-step chemoenzymatic treatment was developed to linearize and distinguish both forms: (1) N-terminal acetylation that pre-labels the acyclotides; (2) conversion of Cys into pseudo-Lys through aziridine-mediated S-alkylation to reduce disulfide bonds and to increase the net charge of peptides; and (3) opening of cyclic backbones by the novel asparaginyl endopeptidase butelase 2 that cleaves at the native bioprocessing site. The treated peptides are subsequently analyzed by liquid chromatography coupled to mass spectrometry using electron transfer dissociation fragmentation and sequences are identified by matching the MS/MS spectra directly with the transcriptomic database.

  12. Differential Expression of Cysteine Dioxygenase 1 in Complex Karyotype Liposarcomas

    Directory of Open Access Journals (Sweden)

    Mohammed Shaker

    2014-01-01

    Full Text Available Altered cysteine dioxygenase 1 (CDO1 gene expression has been observed in several cancers but has not yet been investigated in liposarcomas. The aim of this study was to evaluate CDO1 expression in a cohort of liposarcomas and to determine its association with clinicopathological features. Existing microarray data indicated variable CDO1 expression in liposarcoma subtypes. CDO1 mRNA from a larger cohort of liposarcomas was quantified by real time-PCR, and CDO1 protein expression was determined by immunohistochemistry (IHC in more than 300 tumor specimens. Well-differentiated liposarcomas (WDLSs had significantly higher CDO1 gene expression and protein levels than dedifferentiated liposarcomas (DDLSs ( P < 0.001. Location of the tumor was not predictive of the expression level of CDO1 mRNA in any histological subtype of liposarcoma. Recurrent tumors did not show any difference in CDO1 expression when compared to primary tumors. CDO1 expression was upregulated as human mesenchymal stem cells (hMSCs undergo differentiation into mature adipocytes. Our results suggest that CDO1 is a marker of liposarcoma progression and adipogenic differentiation.

  13. Cysteine-independent activation/inhibition of heme oxygenase-2.

    Science.gov (United States)

    Vukomanovic, Dragic; Rahman, Mona N; Maines, Mahin D; Ozolinš, Terence Rs; Szarek, Walter A; Jia, Zongchao; Nakatsu, Kanji

    2016-03-01

    Reactive thiols of cysteine (cys) residues in proteins play a key role in transforming chemical reactivity into a biological response. The heme oxygenase-2 (HO-2) isozyme contains two cys residues that have been implicated in binding of heme and also the regulation of its activity. In this paper, we address the question of a role for cys residues for the HO-2 inhibitors or activators designed in our laboratory. We tested the activity of full length recombinant human heme oxygenase-2 (FL-hHO-2) and its analog in which cys265 and cys282 were both replaced by alanine to determine the effect on activation by menadione (MD) and inhibition by QC-2350. Similar inhibition by QC-2350 and almost identical activation by MD was observed for both recombinant FL-hHO-2s. Our findings are interpreted to mean that thiols of FL-hHO-2s are not involved in HO-2 activation or inhibition by the compounds that have been designed and identified by us. Activation or inhibition of HO-2 by our compounds should be attributed to a mechanism other than altering binding affinity of HO-2 for heme through cys265 and cys282.

  14. Identification and preliminary characterization of protein-cysteine farnesyltransferase

    International Nuclear Information System (INIS)

    Manne, V.; Roberts, D.; Tobin, A.; O'Rourke, E.; Barbacid, M.; De Virgilio, M.; Meyers, C.; Ahmed, N.; Kurz, B.; Resh, M.; Kung, Hsiang-Fu

    1990-01-01

    Ras proteins must be isoprenylated at a conserved cysteine residue near the carboxyl terminus in order to exert their biological activity. Previous studies indicate that an intermediate in the mevalonate pathway, most likely farnesyl pyrophosphate, is the donor of this isoprenyl group. Inhibition of mevalonate synthesis reverts the abnormal phenotypes induced by the mutant RAS2 Valendash19 gene in Saccharomyces cerevisiae and blocks the maturation of Xenopus oocytes induced by an onocogenic Ras p21 protein of human origin. These results have raised the possibility of using inhibitors of the mevalonate pathway to block the transforming properties of ras oncogenes. Unfortunately, mevalonate is a precursor of various end products essential to mammalian cells, such as dolichols, ubiquinones, heme A, and cholesterol. In this study, the authors describe an enzymatic activity(ies) capable of catalyzing the farnesylation of unprocessed Ras p21 proteins in vitro at the correct (Cys-186) residue. Gel filtration analysis of a partially purified preparation of protein farnesyltransferase revealed two peaks of activity at 250-350 kDa and 80-130 kDa. Availability of an in vitro protein farnesyltransferase assay should be useful in screening for potential inhibitors of ras oncogene function that will not interfere with other aspects of the mevalonate pathway

  15. 18 CFR 3c.1 - Cross-reference to employee ethical conduct standards and financial disclosure regulations.

    Science.gov (United States)

    2010-04-01

    ... employee ethical conduct standards and financial disclosure regulations. 3c.1 Section 3c.1 Conservation of... STANDARDS OF CONDUCT § 3c.1 Cross-reference to employee ethical conduct standards and financial disclosure... branch-wide financial disclosure regulations at 5 CFR part 2634, the Standards of Ethical Conduct for...

  16. A turn-on fluorescent sensor for the discrimination of cystein from homocystein and glutathione.

    Science.gov (United States)

    Niu, Li-Ya; Guan, Ying-Shi; Chen, Yu-Zhe; Wu, Li-Zhu; Tung, Chen-Ho; Yang, Qing-Zheng

    2013-02-14

    We report a turn-on fluorescent sensor based on nitrothiophenolate boron dipyrromethene (BODIPY) derivatives for the discrimination of cystein (Cys) from homocystein (Hcy) and glutathione (GSH). The sensor was applied for detection of Cys in living cells.

  17. Enzymatic synthesis of S-phenyl-L-cysteine from keratin hydrolysis industries wastewater with tryptophan synthase.

    Science.gov (United States)

    Xu, Lisheng; Wang, Zhiyuan; Mao, Pingting; Liu, Junzhong; Zhang, Hongjuan; Liu, Qian; Jiao, Qing-Cai

    2013-04-01

    An economical method for production of S-phenyl-L-cysteine from keratin acid hydrolysis wastewater (KHW) containing L-serine was developed by recombinant tryptophan synthase. This study provides us with an alternative KHW utilization strategy to synthesize S-phenyl-L-cysteine. Tryptophan synthase could efficiently convert L-serine contained in KHW to S-phenyl-L-cysteine at pH 9.0, 40°C and Trion X-100 of 0.02%. In a scale up study, L-serine conversion rate reach 97.1% with a final S-phenyl-L-cysteine concentration of 38.6 g l(-1). Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Facile and green synthesis of highly stable L-cysteine functionalized copper nanoparticles

    Science.gov (United States)

    Kumar, Nikhil; Upadhyay, Lata Sheo Bachan

    2016-11-01

    A simple eco-friendly method for L-cysteine capped copper nanoparticles (CCNPs) synthesis in aqueous solution has been developed. Glucose and L-cysteine were used as reducing agent and capping/functionalizing agent, respectively. Different parameters such as capping agent concentration, pH, reaction temperature, and reducing agent concentration were optimized during the synthesis. The L-cysteine capped copper nanoparticle were characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, Particle size and zeta potential analyser, and high resolution transmission electron microscopy. Spherical shaped cysteine functionalized/capped copper nanoparticles with an average size of 40 nm were found to be highly stable at room temperature (RT) for a period of 1 month

  19. The Cysteine S-Alkylation Reaction as a Synthetic Method to Covalently Modify Peptide Sequences.

    Science.gov (United States)

    Calce, Enrica; De Luca, Stefania

    2017-01-05

    Synthetic methodologies to chemically modify peptide molecules have long been investigated for their impact in the field of chemical biology. They allow the introduction of biochemical probes useful for studying protein functions, for manipulating peptides with therapeutic potential, and for structure-activity relationship investigations. The commonly used approach was the derivatization of an amino acid side chain. In this regard, the cysteine, for its unique reactivity, has been widely employed as the substrate for such modifications. Herein, we report on methodologies developed to modify the cysteine thiol group through the S-alkylation reaction. Some procedures perform the alkylation of cysteine derivatives, in order to prepare building blocks to be used during the peptide synthesis, whilst some others selectively modify peptide sequences containing a cysteine residue with a free thiol group, both in solution and in the solid phase. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Chiral supramolecular gold-cysteine nanoparticles: Chiroptical and nonlinear optical properties

    Directory of Open Access Journals (Sweden)

    Isabelle Russier-Antoine

    2016-10-01

    Full Text Available Cysteine is a sulfur-containing amino acid that easily coordinates to soft metal ions and grafts to noble metal surfaces. We report a simple synthetic approach for the production of chiral gold-cysteine polymeric nanoparticles soluble in water. Conjugation of cysteine with gold in a polymeric way, leading to ~50 nm diameter nanoparticles, resulted in the generation of new characteristic circular dichroism (CD signals in the region of 250–400 nm, whereas no CD signal changes were found with cysteine alone. We also investigate their nonlinear optical properties after two-photon absorption. Two-photon emission spectra and first hyper-polarizabilities, as obtained by the hyper-Rayleigh scattering technique, of these particles are presented.

  1. Development of a cysteine-deprived and C-terminally truncated GLP-1 receptor

    DEFF Research Database (Denmark)

    Underwood, Christina Rye; Knudsen, Lotte Bjerre; Garibay, Patrick W.

    2013-01-01

    The glucagon-like peptide-1 receptor (GLP-1R) belongs to family B of the G-protein coupled receptors (GPCRs), and has become a promising target for the treatment of type 2 diabetes. Here we describe the development and characterization of a fully functional cysteine-deprived and C......-terminally truncated GLP-1R. Single cysteines were initially substituted with alanine, and functionally redundant cysteines were subsequently changed simultaneously. Our results indicate that Cys174, Cys226, Cys296 and Cys403 are important for the GLP-1-mediated response, whereas Cys236, Cys329, Cys341, Cys347, Cys438...... that the membrane proximal part of the C-terminal is involved in receptor expression at the cell surface. The results show that seven cysteines and more than half of the C-terminal tail can be removed from GLP-1R without compromising GLP-1 binding or function....

  2. Controllable synthesis of TiO2 nanomaterials by assisting with l-cysteine and ethylenediamine

    KAUST Repository

    Tao, Yugui

    2013-11-21

    This paper reports a facile l-cysteine-assisted solvothermal synthesis of TiO2 nanomaterials using ethylenediamine (En) and distilled water as solvent. The influence of reaction time, temperature, l-cysteine and solvent was initially investigated. Results demonstrated the reaction temperature, l-cysteine and En significantly imposed impact on the phase and morphology of the particles. Amorphous nanosheets, mixed-crystal nanorods and pure anatase nanoparticles were controllably synthesized by varying reaction temperature. The formation of the amorphous nanosheets and mixed-crystal nanorods were directly affected by the presence of l-cysteine and En. And the presence of En distinctly affected the crystal phase of the products, which was rarely mentioned in other studies. Moreover, the photocatalytic activities of three typical samples were excellent. The possible formation mechanism of the sample was also discussed. © 2013 Springer Science+Business Media New York.

  3. Controllable synthesis of TiO2 nanomaterials by assisting with l-cysteine and ethylenediamine

    KAUST Repository

    Tao, Yugui; Cao, Ning; Pan, Jun; Sun, Yichen; Jin, Cheng; Song, Yang

    2013-01-01

    This paper reports a facile l-cysteine-assisted solvothermal synthesis of TiO2 nanomaterials using ethylenediamine (En) and distilled water as solvent. The influence of reaction time, temperature, l-cysteine and solvent was initially investigated. Results demonstrated the reaction temperature, l-cysteine and En significantly imposed impact on the phase and morphology of the particles. Amorphous nanosheets, mixed-crystal nanorods and pure anatase nanoparticles were controllably synthesized by varying reaction temperature. The formation of the amorphous nanosheets and mixed-crystal nanorods were directly affected by the presence of l-cysteine and En. And the presence of En distinctly affected the crystal phase of the products, which was rarely mentioned in other studies. Moreover, the photocatalytic activities of three typical samples were excellent. The possible formation mechanism of the sample was also discussed. © 2013 Springer Science+Business Media New York.

  4. 7-cysteine-pyrrole conjugate: A new potential DNA reactive metabolite of pyrrolizidine alkaloids.

    Science.gov (United States)

    He, Xiaobo; Xia, Qingsu; Ma, Liang; Fu, Peter P

    2016-01-01

    Pyrrolizidine alkaloids (PAs) require metabolic activation to exert cytotoxicity, genotoxicity, and tumorigenicity. We previously reported that (±)-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-derived DNA adducts are responsible for PA-induced liver tumor formation in rats. In this study, we determined that metabolism of riddelliine and monocrotaline by human or rat liver microsomes produced 7-cysteine-DHP and DHP. The metabolism of 7-glutathionyl-DHP by human and rat liver microsomes also generated 7-cysteine-DHP. Further, reaction of 7-cysteine-DHP with calf thymus DNA in aqueous solution yielded the described DHP-derived DNA adducts. This study represents the first report that 7-cysteine-DHP is a new PA metabolite that can lead to DNA adduct formation.

  5. High-performance liquid chromatography-fluorescence assay of pyruvic acid to determine cysteine conjugate beta-lyase activity : application to S-1,2-dichlorovinyl-L-cysteine and S-2-benzothiazolyl-L-cysteine

    NARCIS (Netherlands)

    Stijntjes, G.J.; te Koppele, J.M.; Vermeulen, N P

    1992-01-01

    An HPLC-fluorescence assay has been developed for the determination of the activity of rat renal cytosolic cysteine conjugate beta-lyase. The method is based on isocratic HPLC separation and fluorescence detection of pyruvic acid, derivatized with o-phenylenediamine (OPD), and is shown to be rapid,

  6. Mechanism of S-oxygenation by a cysteine dioxygenase model complex

    OpenAIRE

    Kumar, Devesh; Sastry, G. Narahari; Goldberg, David P.; de Visser, Sam P.

    2011-01-01

    In this work we present the first computational study on a biomimetic cysteine dioxygenase model complex, [FeII(LN3S)]+ where LN3S is a tetradentate ligand with a bis(imino)pyridyl scaffold and a pendant arylthiolate group. The reaction mechanism of sulfur dioxygenation with O2 was examined by density functional theory (DFT) methods, and compared to results obtained for cysteine dioxygenase. The reaction proceeds via multistate reactivity patterns on competing singlet, triplet and quintet spi...

  7. [Protective Effect of S-isopentenyl-L-cysteine against DNA Damage in Irradiated Mice].

    Science.gov (United States)

    Zheng, Qi-sheng; Yu, Guang-yun; He, Xin; Jiang, Ming; Chu, Xiao-fei; Zhao, Shu-yi; Fan, Sai-jun; Liu, Pei-xun

    2015-10-01

    To evaluate the protective effect of S-isopentenyl-L-cysteine,a new cysteine derivative,on DNA damage induced by radiation by using acute radiation injury animal models. Forty ICR mice were randomly divided into five groups:the control group,1.0Gy gamma irradiation group,1.0Gy gamma irradiation combined with S-isopentenyl-L-cysteine group,7.2Gy gamma irradiation group,and 7.2Gy gamma irradiation combined with S-isopentenyl-L-cysteine group,with 8 mice in each group.The comet assay and bone marrow polychromatic micronucleus experiments were performed to evaluate the double-strand DNA breaks in ICR mice exposed to 1.0 and 7.2Gy gamma-ray, respectively. The tail DNA percentage,tail length,tail moment,and olive tail moment of peripheral blood lymphocytes in 7.2Gy gamma irradiation group were significantly higher than that of the control group (PL-cysteine group was significantly less than that of 7.2Gy gamma irradiation group (PL-cysteine before irradiation,the micronucleus rate of ICR mice exposed to 1.0 and 7.2Gy gamma-ray decreased from (39.5000 ± 3.3141)‰ to (28.1667±4.1345)‰ (P=0.033) and from (76.5000 ± 4.6242)‰ to (22.8333 ± 3.6553)‰(P=0.000),respectively. The bone marrow polychromatic micronucleus experiment indicated that the value of polychromatic erythrocyte (PCE)/normochromatic erythrocyte(NCE) of ICR mice exposed to 1.0 and 7.2Gy gamma-ray was less than the control group(PL-cysteine before irradiation was significantly higher than the corresponding groups (PL-cysteine has a good protective effect against DNA damage induced by radiation.

  8. Transamination of cysteine-sulfinic acid by extracts of oat leaves

    International Nuclear Information System (INIS)

    Perez-Milan, H.; Schuack, J.; Fromageot, P.

    1960-01-01

    An aqueous extract of oat leaves catalyses a transamination between cysteine-sulfinic acid and α-ketoglutaric acid. Under the conditions utilized pyruvic acid is not an acceptor of the amino group. Neither cysteic nor aspartic acid are a substrate for the transaminase of cysteine-sulfinic acid. Reprint of a paper published in Biochimica et Biophysica Acta, Vol. 36, 1959, p. 73-83 [fr

  9. Study of the histochemical detection of cysteine desulfhydrase in the vitellin sac of birds (1961)

    International Nuclear Information System (INIS)

    Chapeville, F.; Khau Van Kien, L.

    1961-01-01

    We have developed a method for the histochemical detection of cysteine desulfhydrase in the vitellin sac of the chicken embryo. The enzyme is localized in the presence of a lead salt by lead sulphide formed in situ from hydrogen sulphide liberated from the cysteine. The micrographs obtained are histological and show the presence of the enzyme in the different types of endoderm cell. (authors) [fr

  10. Correlation of secreted protein acidic and rich in cysteine with diabetic nephropathy

    OpenAIRE

    Li, Lei; Song, Hai-Yan; Liu, Kai; An, Meng-Meng

    2015-01-01

    To detect the serum concentrations of secreted protein acidic and rich in cysteine (SPARC) in patients with diabetic nephropathy and SPARC mRNA and protein expressions in renal tissue of db/db mice (C57BL/KsJ, diabetic nephropathy mice), thus preliminary exploration on the role of secreted protein acidic riches in cysteine in the development of diabetic nephropathy were carried out. Serum SPARC levels in normal subjects, patients with type 2 diabetes mellitus (without diabetic nephropathy), c...

  11. Protein Topology Determines Cysteine Oxidation Fate: The Case of Sulfenyl Amide Formation among Protein Families

    Science.gov (United States)

    Defelipe, Lucas A.; Lanzarotti, Esteban; Gauto, Diego; Marti, Marcelo A.; Turjanski, Adrián G.

    2015-01-01

    Cysteine residues have a rich chemistry and play a critical role in the catalytic activity of a plethora of enzymes. However, cysteines are susceptible to oxidation by Reactive Oxygen and Nitrogen Species, leading to a loss of their catalytic function. Therefore, cysteine oxidation is emerging as a relevant physiological regulatory mechanism. Formation of a cyclic sulfenyl amide residue at the active site of redox-regulated proteins has been proposed as a protection mechanism against irreversible oxidation as the sulfenyl amide intermediate has been identified in several proteins. However, how and why only some specific cysteine residues in particular proteins react to form this intermediate is still unknown. In the present work using in-silico based tools, we have identified a constrained conformation that accelerates sulfenyl amide formation. By means of combined MD and QM/MM calculation we show that this conformation positions the NH backbone towards the sulfenic acid and promotes the reaction to yield the sulfenyl amide intermediate, in one step with the concomitant release of a water molecule. Moreover, in a large subset of the proteins we found a conserved beta sheet-loop-helix motif, which is present across different protein folds, that is key for sulfenyl amide production as it promotes the previous formation of sulfenic acid. For catalytic activity, in several cases, proteins need the Cysteine to be in the cysteinate form, i.e. a low pKa Cys. We found that the conserved motif stabilizes the cysteinate by hydrogen bonding to several NH backbone moieties. As cysteinate is also more reactive toward ROS we propose that the sheet-loop-helix motif and the constraint conformation have been selected by evolution for proteins that need a reactive Cys protected from irreversible oxidation. Our results also highlight how fold conservation can be correlated to redox chemistry regulation of protein function. PMID:25741692

  12. Preparation and application of L-cysteine-doped Keggin polyoxometalate microtubes

    International Nuclear Information System (INIS)

    Shen Yan; Peng Jun; Zhang Huanqiu; Meng Cuili; Zhang Fang

    2012-01-01

    L-cysteine-doped tungstosilicate (Lcys-SiW 12 ) microtubes are prepared, and the amount of L-cysteine doped in the microtubes can be tuned to some extent. The as-prepared Lcys-SiW 12 microtubes are sensitive to ammonia gas exhibited through the distinct color change of the microtubes from light purple to dark blue after exposing to ammonia gas. A possible mechanism of the coloration is that the adsorbed ammonia molecules increase the basicity of the Lcys-SiW 12 microtubes and promote the redox reaction between L-cysteine and polyoxometalate. This is a pH-dependent solid–solid redox reaction, which is triggered by proton capture agent. The Lcys-SiW 12 microtubes show application in chemical sensors for alkaline gases. - Graphical abstract: The Lcys-SiW 12 microtubes were formed during transformation of the monolacunary Keggin-type [α-SiW 11 O 39 ] 8− to the saturated Keggin-type [α-SiW 12 O 40 ] 4− , meanwhile L-cysteine molecules were doped during the growth of the microtubes. Highlights: ► L-cysteine-doped polyoxometalate microtubes are prepared. ► Amount of L-cysteine doped in the microtubes can be tuned to some extent. ► Lcys-SiW 12 microtubes can be applied as a sensor for detecting alkaline gases. ► This is a proton capture agent-triggered solid–solid redox reaction.

  13. Structural influence in the interaction of cysteine with five coordinated copper complexes: Theoretical and experimental studies

    Science.gov (United States)

    Huerta-Aguilar, Carlos Alberto; Thangarasu, Pandiyan; Mora, Jesús Gracia

    2018-04-01

    Copper complexes of N,N,N‧,N‧-tetrakis(pyridyl-2-ylmethyl)-1,2-diaminoethane (L1) and N,N,N‧,N‧-tetrakis(pyridyl-2-ylmethyl)-1,3-diaminopropane (L2) prepared were characterized completely by different analytical methods. The X-structure of the complexes shows that Cu(II) presents in trigonal bi-pyramidal (TBP) geometry, consisting with the electronic spectra where two visible bands corresponding to five coordinated structure were observed. Thus TD-DFT was used to analyze the orbital contribution to the electronic transitions for the visible bands. Furthermore, the interaction of cysteine with the complexes was spectrally studied, and the results were explained through DFT analysis, observing that the geometrical parameters and oxidation state of metal ions play a vital role in the binding of cysteine with copper ion. It appears that the TBP structure is being changed into octahedral geometry during the addition of cysteine to the complexes as two bands (from complex) is turned to a broad band in visible region, signifying the occupation of cysteine molecule at sixth position of octahedral geometry. In the molecular orbital analysis, the existence of a strong overlapping of HOMOs (from cysteine) with LUMOs of Cu ion was observed. The total energy of the systems calculated by DFT shows that cysteine binds favorably with copper (I) than that with Cu(II).

  14. Electrochemical behavior of cysteine at a CuGeO3 nanowires modified glassy carbon electrode

    International Nuclear Information System (INIS)

    Dong Yongping; Pei Lizhai; Chu Xiangfeng; Zhang Wangbing; Zhang Qianfeng

    2010-01-01

    A CuGeO 3 nanowire modified glassy carbon electrode was fabricated and characterized by scanning electron microscopy. The results of electrochemical impedance spectroscopy reveal that electron transfer through nanowire film is facile compared with that of bare glassy carbon electrode. The modified electrode exhibited a novel electrocatalytic behavior to the electrochemical reactions of L-cysteine in neutral solution, which was not reported previously. Two pairs of semi-reversible electrochemical peaks were observed and assigned to the processes of oxidation/reduction and adsorption/desorption of cysteine at the modified electrode, respectively. The electrochemical response of cysteine is poor in alkaline condition and is enhanced greatly in acidic solution, suggesting that hydrogen ions participate in the electrochemical oxidation process of cysteine. The intensities of two anodic peaks varied linearly with the concentration of cysteine in the range of 1 x 10 -6 to 1 x 10 -3 mol L -1 , which make it possible to sensitive detection of cysteine with the CuGeO 3 nanowire modified electrode. Furthermore, the modified electrode exhibited good reproducibility and stability.

  15. Electrochemical behaviour of dopamine at covalent modified glassy carbon electrode with l-cysteine: preliminary results

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Martínez-Huitle

    2009-01-01

    Full Text Available The surface of glassy carbon (GC electrode has been modified by oxidation of L-cysteine. The covalent modified GC electrode with L-Cysteine has been studied, according the supporting electrolyte used. Favourable interactions between the L-cysteine film and DA enhance the current response compared to that at the Nafion GC and bare GC electrodes, achieving better performances than those other electrodes. This behaviour was as result of the adsorption of the cysteine layer film, compact and uniform formation; depending on L-cysteine solution (phosphate buffer or chloridric acid supporting electrolyte used for modifying GC surface. In cyclic voltammetric measurements, modified electrodes can successfully separate the oxidation/reduction DA peaks in different buffer solutions, but an evident dependence in the response was obtained as function of pH and modified electrode. The modified electrode prepared with L-cysteine/HCl solution was used to obtain the calibration curve and it exhibited a stable and sensitive response to DA. The results are described and discussed in the light of the existing literature.

  16. Depletion of circulating cyst(e)ine by oral and intravenous mesna.

    Science.gov (United States)

    Stofer-Vogel, B.; Cerny, T.; Küpfer, A.; Junker, E.; Lauterburg, B. H.

    1993-01-01

    The sulfhydryl status of normal and tumour cells is critically important in determining their susceptibility to various cytostatic agents. As a sulfhydryl compound, mesna (sodium 2-mercaptoethane-sulfonate) which is used in large doses to prevent haemorrhagic cystitis associated with certain chemotherapeutic regimens might derange cellular thiol homeostasis. In order to investigate the effects of mesna on the concentrations of thiols in plasma, cysteine, glutathione and their disulfides were measured by HPLC following the oral and intravenous administration of mesna to healthy volunteers. After 7.3 mmol mesna i.v. free cysteine rose from 8.2 (95% CI 7.0-9.4) nmol ml-1 to 53.6 (47.4-59.8) nmol ml-1 at 5 min, most likely due to reduction of circulating cystine by the sulfhydryl drug. This initial rise was followed by a marked decrease of total cyst(e)ine in plasma from 276 (215-337) nmol ml-1 to a nadir of 102 (89-115) nmol ml-1 between 30-120 min after infusion, most likely due to an increased uptake of cysteine into cells and an increased urinary excretion of cyst(e)ine. Qualitatively similar changes were seen after oral mesna. The present data indicate that mesna depletes circulating cyst(e)ine and may thereby markedly alter the sulfhydryl status of cells in vivo although the drug itself is not taken up by most cells. PMID:8353049

  17. Electrical activation of nitrogen heavily implanted 3C-SiC(1 0 0)

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fan, E-mail: f.li.1@warwick.ac.uk [School of Engineering, University of Warwick, Coventry CV4 7AL (United Kingdom); Sharma, Yogesh; Shah, Vishal; Jennings, Mike [School of Engineering, University of Warwick, Coventry CV4 7AL (United Kingdom); Pérez-Tomás, Amador [ICN2 – Institut Catala de Nanociència i Nanotecnologia, Campus UAB, 08193 Bellaterra, Barcelona (Spain); Myronov, Maksym [Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom); Fisher, Craig [School of Engineering, University of Warwick, Coventry CV4 7AL (United Kingdom); Leadley, David [Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom); Mawby, Phil [School of Engineering, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2015-10-30

    Highlights: • Nitrogen is fully activated by 1175 °C annealing for 1.5 × 10{sup 19} cm{sup −3} doped 3C-SiC. • Free donor concentration is found to readily saturate in 3C-SiC at ∼7 × 10{sup 19} cm{sup −3}. • 3C-SiC is found to have complete donor thermal ionization above 150 K. • Donor in 1.5 × 10{sup 19} cm{sup −3} nitrogen implanted 3C-SiC has an energy level ∼15 meV. • The SiO{sub 2} cap is found to have a bigger influence on low and medium doped samples. - Abstract: A degenerated wide bandgap semiconductor is a rare system. In general, implant levels lie deeper in the band-gap and carrier freeze-out usually takes place at room temperature. Nevertheless, we have observed that heavily doped n-type degenerated 3C-SiC films are achieved by nitrogen implantation level of ∼6 × 10{sup 20} cm{sup −3} at 20 K. According to temperature dependent Hall measurements, nitrogen activation rates decrease with the doping level from almost 100% (1.5 × 10{sup 19} cm{sup −3}, donor level 15 meV) to ∼12% for 6 × 10{sup 20} cm{sup −3}. Free donors are found to saturate in 3C-SiC at ∼7 × 10{sup 19} cm{sup −3}. The implanted film electrical performances are characterized as a function of the dopant doses and post implantation annealing (PIA) conditions by fabricating Van der Pauw structures. A deposited SiO{sub 2} layer was used as the surface capping layer during the PIA process to study its effect on the resultant film properties. From the device design point of view, the lowest sheet resistivity (∼1.4 mΩ cm) has been observed for medium doped (4 × 10{sup 19} cm{sup −3}) sample with PIA 1375 °C 2 h without a SiO{sub 2} cap.

  18. L-Cysteine halogenides: A new family of salts with an L-cysteine⋯L-cysteinium dimeric cation

    Science.gov (United States)

    Ghazaryan, V. V.; Minkov, V. S.; Boldyreva, E. V.; Petrosyan, A. M.

    2016-10-01

    Two L-cysteinium-halogenides with (L-cysteine···L-cysteinium) dimeric cations have been obtained, (L-Cys⋯L-Cys+)·Cl-, and (L-Cys⋯L-Cys+)·Br-. Both salts crystallize in monoclinic space group P21. Although these salts have the same dimeric cations and isotypical halogen anions, crystal packing is different. The main difference between the two salts rests in the conformation of (L-Cys⋯L-Cys+) dimeric cation, which also differs from that of the dimeric cation in the previously reported compound L-Cys+(L-Cys⋯L-Cys+)·F-·(F-⋯HF). The dimeric cation is formed by a very short O-H⋯O hydrogen bond with d(O···O) of 2.449(2) Å and 2.435(11) Å in the chloride and bromide, respectively. In addition to crystal structure analysis, Infrared and Raman spectra have been registered and discussed with a particular focus on intermolecular interactions. The L-Cys+·Br-·H2O salt with a simple L-cysteinium cation was also obtained and the crystal structure solved. It resembles its chloride analogue, L-Cys+·Cl-·H2O.

  19. Transcription factor DecR (YbaO) controls detoxification of L-cysteine in Escherichia coli.

    Science.gov (United States)

    Shimada, Tomohiro; Tanaka, Kan; Ishihama, Akira

    2016-09-01

    YbaO is an uncharacterized AsnC-family transcription factor of Escherichia coli. In both Salmonella enterica and Pantoea ananatis, YbaO homologues were identified to regulate the adjacent gene encoding cysteine desulfhydrase for detoxification of cysteine. Using the genomic SELEX (systematic evolution of ligands by exponential enrichment) screening system, we identified the yhaOM operon, located far from the ybaO gene on the E. coli genome, as a single regulatory target of YbaO. In both gel shift assay in vitro and reporter and Northern blot assays in vivo, YbaO was found to regulate the yhaOM promoter. The growth of mutants lacking either ybaO or its targets yhaOM was delayed in the presence of cysteine, indicating involvement of these genes in cysteine detoxification. In the major pathway of cysteine degradation, hydrogen sulfide is produced in wild-type E. coli, but its production was not observed in each of the ybaO, yhaO and yhaM mutants. The yhaOM promoter was activated in the presence of cysteine, implying the role of cysteine in activation of YbaO. Taken together, we propose that YbaO is the cysteine-sensing transcriptional activator of the yhaOM operon, which is involved in the detoxification of cysteine. We then propose the naming of ybaO as decR (regulator of detoxification of cysteine).

  20. Multimodal interaction with W3C standards toward natural user interfaces to everything

    CERN Document Server

    2017-01-01

    This book presents new standards for multimodal interaction published by the W3C and other standards bodies in straightforward and accessible language, while also illustrating the standards in operation through case studies and chapters on innovative implementations. The book illustrates how, as smart technology becomes ubiquitous, and appears in more and more different shapes and sizes, vendor-specific approaches to multimodal interaction become impractical, motivating the need for standards. This book covers standards for voice, emotion, natural language understanding, dialog, and multimodal architectures. The book describes the standards in a practical manner, making them accessible to developers, students, and researchers. Comprehensive resource that explains the W3C standards for multimodal interaction clear and straightforward way; Includes case studies of the use of the standards on a wide variety of devices, including mobile devices, tablets, wearables and robots, in applications such as assisted livi...

  1. A new Dirac cone material: a graphene-like Be3C2 monolayer.

    Science.gov (United States)

    Wang, Bing; Yuan, Shijun; Li, Yunhai; Shi, Li; Wang, Jinlan

    2017-05-04

    Two-dimensional (2D) materials with Dirac cones exhibit rich physics and many intriguing properties, but the search for new 2D Dirac materials is still a current hotspot. Using the global particle-swarm optimization method and density functional theory, we predict a new stable graphene-like 2D Dirac material: a Be 3 C 2 monolayer with a hexagonal honeycomb structure. The Dirac point occurs exactly at the Fermi level and arises from the merging of the hybridized p z bands of Be and C atoms. Most interestingly, this monolayer exhibits a high Fermi velocity in the same order of graphene. Moreover, the Dirac cone is very robust and retains even included spin-orbit coupling or external strain. These outstanding properties render the Be 3 C 2 monolayer a promising 2D material for special electronics applications.

  2. Nonlinear bias analysis and correction of microwave temperature sounder observations for FY-3C meteorological satellite

    Science.gov (United States)

    Hu, Taiyang; Lv, Rongchuan; Jin, Xu; Li, Hao; Chen, Wenxin

    2018-01-01

    The nonlinear bias analysis and correction of receiving channels in Chinese FY-3C meteorological satellite Microwave Temperature Sounder (MWTS) is a key technology of data assimilation for satellite radiance data. The thermal-vacuum chamber calibration data acquired from the MWTS can be analyzed to evaluate the instrument performance, including radiometric temperature sensitivity, channel nonlinearity and calibration accuracy. Especially, the nonlinearity parameters due to imperfect square-law detectors will be calculated from calibration data and further used to correct the nonlinear bias contributions of microwave receiving channels. Based upon the operational principles and thermalvacuum chamber calibration procedures of MWTS, this paper mainly focuses on the nonlinear bias analysis and correction methods for improving the calibration accuracy of the important instrument onboard FY-3C meteorological satellite, from the perspective of theoretical and experimental studies. Furthermore, a series of original results are presented to demonstrate the feasibility and significance of the methods.

  3. Characterization of nanoporous Al{sub 2}O{sub 3}:C for thermoluminescent radiation dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Barros, V.S.M. de [Departamento de Energia Nuclear-UFPE, Rua prof Luiz Freire, 1000, Recife, PE 50740-540 (Brazil)], E-mail: vdbarros@terra.com.br; Khoury, H.J. [Departamento de Energia Nuclear-UFPE, Rua prof Luiz Freire, 1000, Recife, PE 50740-540 (Brazil); Azevedo, W.M. [Departamento de Quimica Fundamental-CCEN Recife, PE 50740-540 (Brazil); Silva, E.F. da [Departamento de Fisica CCEN Recife, PE 50740-540 (Brazil)

    2007-09-21

    Thermoluminescent (TL) {alpha}-Al{sub 2}O{sub 3}:C dosimeters, produced in the form of single crystals, show a high sensitivity to ionizing radiation (about 40-60 times higher than LiF:Mg,Ti). However, the crystal growth requires high temperatures (2050 deg. C) and highly reducing atmospheres. This paper presents the TL response of thin nanoporous Al{sub 2}O{sub 3}:C membranes obtained by electrochemical anodizing of aluminum in organic acid solutions at room temperature. The TL properties of the samples were analyzed as a function of the anodizing voltage in the interval 30-60 V and of the acid concentrations from 0.05 to 0.6 M. The dosimetric response of the samples for {sup 60}Co gamma radiation is linear with dose, and the best response was found for samples anodized at 130 V with 0.10 M acid concentration.

  4. Synchrotron radiation photoemission spectrum study on K3C60 film

    Institute of Scientific and Technical Information of China (English)

    李宏年; 徐亚伯; 鲍世宁; 李海洋; 何丕模; 钱海杰; 刘风琴; 奎热西·易卜拉欣

    2000-01-01

    K3C60 single crystal film was prepared on the cleaved (111) surface of C60 single crystal. Synchrotron radiation angle-resolved photoemission spectra were measured at normal emission with sample temperature at - 150K. Up to four subpeaks of LUMO-derived band were observed. These sub-peaks exhibit distinct energy dispersions which resemble in general the theoretical ones calculated for K3C60 at low temperature with the so-called one-dimensional disordered structure. But there is large deviation of experimental sub-band intervals from the theoretical values. This result is meaningful for the studies of the physical properties of alkali-doped C60 solids, e.g. the mechanism for superconductivity.

  5. Fe{sub 3}C/Fe nanoparticles with urea: Synthesis, structure and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaobai [College of Chemistry, Jilin University, Changchun, 130012 (China); School of Chemical and Pharmaceutical Engineering, Jilin Institute of Chemical Technology, Jilin, 132022 (China); Zhang, Daguang [Department of Orthopaedic Surgery, the First Hospital of Jilin University, Changchun, 130021 China (China); Ren, Xiaozhen; Gao, Jiajia [College of Chemistry, Jilin University, Changchun, 130012 (China); Han, Yu [Department of Chemistry, College of Science, Yanbian University, Yanji, 133002 China (China); Chen, Xiaodong [College of Chemistry, Jilin University, Changchun, 130012 (China); Shi, Zhan [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012 (China); Yang, Hua [College of Chemistry, Jilin University, Changchun, 130012 (China)

    2016-12-15

    Fe{sub 3}C/Fe nanocomposites were synthesized by a sol–gel method. Using urea as carbon source and reduce agent in the reaction process. The CTAB works as the surfactant and the bromine contained in CTAB plays a catalytic role. Appropriate choices of the amount of urea and CTAB, reaction temperature and time are very important to obtain high-quality of products. Above 650 °C, the precursor gel turned into the nanocomposites composed of iron carbide and iron. Their structures and magnetic properties are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The possible formation mechanism of as-prepared nanostructures is discussed. - Highlights: • The Fe{sub 3}C/Fe composites were synthetized by sol–gel method. • Their structure, magnetic properties are researched by XRD, VSM and TEM. • The possible formation mechanisms of the composites is discussed.

  6. Evolution of a practical total synthesis of ciguatoxin CTX3C.

    Science.gov (United States)

    Inoue, Masayuki; Hirama, Masahiro

    2004-12-01

    More than 20 000 people suffer annually from ciguatera seafood poisoning in subtropical and tropical regions. The extremely low content of the causative neurotoxins, designated as ciguatoxins, in fish has hampered their isolation, detailed biological study, and preparation of anti-ciguatoxin antibodies for detecting these toxins. Ciguatoxins consist of 12 trans-fused polycyclic ethers, ranging from six- to nine-membered, and include a spirally attached five-membered cyclic ether at one end. The large (3 nm in length) and complicated molecular structure of ciguatoxins has impeded chemists from completing their total synthesis. In 2001, we achieved the first total synthesis of ciguatoxin CTX3C by assembly of four structural fragments. Since then, protocols to combine the fragments have significantly improved in terms of overall stereoselectivity, efficiency, and practicality. In this Account, we describe recently evolved methodologies for the total synthesis of CTX3C.

  7. Surface Chemistry Involved in Epitaxy of Graphene on 3C-SiC(111/Si(111

    Directory of Open Access Journals (Sweden)

    Abe Shunsuke

    2010-01-01

    Full Text Available Abstract Surface chemistry involved in the epitaxy of graphene by sublimating Si atoms from the surface of epitaxial 3C-SiC(111 thin films on Si(111 has been studied. The change in the surface composition during graphene epitaxy is monitored by in situ temperature-programmed desorption spectroscopy using deuterium as a probe (D2-TPD and complementarily by ex situ Raman and C1s core-level spectroscopies. The surface of the 3C-SiC(111/Si(111 is Si-terminated before the graphitization, and it becomes C-terminated via the formation of C-rich (6√3 × 6√3R30° reconstruction as the graphitization proceeds, in a similar manner as the epitaxy of graphene on Si-terminated 6H-SiC(0001 proceeds.

  8. Kinetic study of methanol oxidation on Pt2Ru3/C catalyst in the alkaline media

    Directory of Open Access Journals (Sweden)

    A. V. TRIPKOVIC

    2007-11-01

    Full Text Available The interaction of acridine orange (AO with double-stranded (ds The electrochemical oxidation of methanol in NaOH solution was examined on a thin film Pt2Ru3/C electrode. The XRD pattern revealed that the Pt2Ru3 alloy consisted of a solid solution of Ru in Pt and a small amount of Ru or a solid solution of Pt in Ru. It was shown that in alkaline solution, the difference in activity between Pt/C and Pt2Ru3/C is significantly smaller than in acid solution. It is proposed that the reaction follows a quasi bifunctional mechanism. The kinetic parameters indicated that the chemical reaction between adsorbed COad and OHad species could be the rate limiting step.

  9. OPTICAL MONITORING OF TWO BRIGHTEST NEARBY QUASARS, PHL 1811 AND 3C 273

    International Nuclear Information System (INIS)

    Fan, J. H.; Liu, Y.; Yuan, Y. H.; Kurtanidze, O.; Chanishvili, R.; Richter, G. M.

    2014-01-01

    Variability is one of the most observable characteristics of active galactic nuclei, and it is important when considering the emission mechanism. In this paper, we report optical photometry monitoring of two nearby brightest quasars, PHL 1811 and 3C 273, using the ST-6 camera attached to the Newtonian focus and the Ap6E CCD camera attached to the primary focus of the 70 cm meniscus telescope at the Abastumani Observatory, Georgia. PHL 1811 was monitored during the period from 2002 September to 2012 December, while 3C 273 was monitored during the period from 1998 February to 2008 May. During our monitoring period, the two sources did not show any significant intra-day variability. The largest detected variations are ΔR = 0.112 ± 0.010 mag. for PHL 1811, ΔB = 0.595 ± 0.099 mag, ΔV = 0.369 ± 0.028 mag, ΔR = 0.495 ± 0.076 mag, and ΔI = 0.355 ± 0.009 mag for 3C 273. When the periodicity analysis methods are adopted for the observations of the sources, a period of p = 5.80 ± 1.12 yr is obtained for PHL 1811 in the R light curve in the present work, and periods of p = 21.10 ± 0.14, 10.00 ± 0.14, 7.30 ± 0.09, 13.20 ± 0.09, 2.10 ± 0.06, and 0.68 ± 0.05 yr are obtained for 3C 273 based on the data in the present work combined with historical works

  10. OPTICAL MONITORING OF TWO BRIGHTEST NEARBY QUASARS, PHL 1811 AND 3C 273

    Energy Technology Data Exchange (ETDEWEB)

    Fan, J. H.; Liu, Y.; Yuan, Y. H. [Center for Astrophysics, Guangzhou University, Guangzhou 510006 (China); Kurtanidze, O.; Chanishvili, R. [Abastumani Observatory, Mt. Kanobili, 0301 Abastumani, Georgia (United States); Richter, G. M. [Astrophysikalisches Institut Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany)

    2014-08-01

    Variability is one of the most observable characteristics of active galactic nuclei, and it is important when considering the emission mechanism. In this paper, we report optical photometry monitoring of two nearby brightest quasars, PHL 1811 and 3C 273, using the ST-6 camera attached to the Newtonian focus and the Ap6E CCD camera attached to the primary focus of the 70 cm meniscus telescope at the Abastumani Observatory, Georgia. PHL 1811 was monitored during the period from 2002 September to 2012 December, while 3C 273 was monitored during the period from 1998 February to 2008 May. During our monitoring period, the two sources did not show any significant intra-day variability. The largest detected variations are ΔR = 0.112 ± 0.010 mag. for PHL 1811, ΔB = 0.595 ± 0.099 mag, ΔV = 0.369 ± 0.028 mag, ΔR = 0.495 ± 0.076 mag, and ΔI = 0.355 ± 0.009 mag for 3C 273. When the periodicity analysis methods are adopted for the observations of the sources, a period of p = 5.80 ± 1.12 yr is obtained for PHL 1811 in the R light curve in the present work, and periods of p = 21.10 ± 0.14, 10.00 ± 0.14, 7.30 ± 0.09, 13.20 ± 0.09, 2.10 ± 0.06, and 0.68 ± 0.05 yr are obtained for 3C 273 based on the data in the present work combined with historical works.

  11. Sb2S3:C/CdS p-n junction by laser irradiation

    International Nuclear Information System (INIS)

    Arato, A.; Cardenas, E.; Shaji, S.; O'Brien, J.J.; Liu, J.; Castillo, G. Alan; Das Roy, T.K.; Krishnan, B.

    2009-01-01

    In this paper, we report laser irradiated carbon doping of Sb 2 S 3 thin films and formation of a p-n junction photovoltaic structure using these films. A very thin carbon layer was evaporated on to chemical bath deposited Sb 2 S 3 thin films of approximately 0.5 μm in thickness. Sb 2 S 3 thin films were prepared from a solution containing SbCl 3 and Na 2 S 2 O 3 at 27 deg. C for 5 h and the films obtained were highly resistive. These C/Sb 2 S 3 thin films were irradiated by an expanded laser beam of diameter approximately 0.5 cm (5 W power, 532 nm Verdi laser), for 2 min at ambient atmosphere. Morphology and composition of these films were analyzed. These films showed p-type conductivity due to carbon diffusion (Sb 2 S 3 :C) by the thermal energy generated by the absorption of laser radiation. In addition, these thin films were incorporated in a photovoltaic structure Ag/Sb 2 S 3 :C/CdS/ITO/Glass. For this, CdS thin film of 50 nm in thickness was deposited on a commercially available ITO coated glass substrate from a chemical bath containing CdCl 2 , sodium citrate, NH 4 OH and thiourea at 70 deg. C . On the CdS film, Sb 2 S 3 /C layers were deposited. This multilayer structure was subjected to the laser irradiation, C/Sb 2 S 3 side facing the beam. The p-n junction formed by p-Sb 2 S 3 :C and n-type CdS showed V oc = 500 mV and J sc = 0.5 mA/cm 2 under illumination by a tungsten halogen lamp. This work opens up a new method to produce solar cell structures by laser assisted material processing

  12. Ten Years of Monitoring 3C 273 with XMM–Newton Liu Liu ...

    Indian Academy of Sciences (India)

    Abstract. We present ten years optical/UV/X-ray observations of 3C. 273 performed using XMM–Newton between 2000 and 2009. The short- time scale variability behaviour of the soft and hard X-ray light curves may suggest different origins of the soft/hard X-ray emissions. We fit well the 0.2–10 keV X-ray spectrum with a ...

  13. Low-temperature magnetic properties of Fe3C/iron oxide nanocomposite

    Czech Academy of Sciences Publication Activity Database

    David, Bohumil; Schneeweiss, Oldřich; Mašláň, M.; Šantavá, Eva; Morjan, I.

    2007-01-01

    Roč. 316, č. 2 (2007), s. 422-425 ISSN 0304-8853. [Joint European Magnetic Symposia /3./ (JEMS´06). San Sebastian, 26.06.2006-30.06.2006] R&D Projects: GA MŠk 1M0512 Institutional research plan: CEZ:AV0Z20410507; CEZ:AV0Z10100520 Keywords : Nanopowder * Fe3C * Mossbauer spectroscopy * Magnetic properties * AC susceptibility Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.704, year: 2007

  14. Temperature dependence of the Al2O3:C response in medical luminescence dosimetry

    DEFF Research Database (Denmark)

    Edmund, Jens Morgenthaler; Andersen, Claus Erik

    2007-01-01

    is not varied. The RL response only depends on the irradiation temperature. We recommend that calibration should be carried out at the same irradiation temperature at which the measurement is performed (i.e. at body temperature for in vivo measurements). The overall change in the integrated OSL and RL signals...... and detection wavelengths. The reported temperature dependence seems to be a general property of Al2O3:C. (C) 2006 Elsevier Ltd. All rights reserved....

  15. Design of net-gate based on S3C4510B and it's application

    International Nuclear Information System (INIS)

    Wang Yanyu; Li Xiaoqiang; Huang Jijiang; Wang Xiaoyin; Lin Feiyu; Chinese Academy of Sciences, Beijing

    2008-01-01

    This paper introduces a solution of the net-gate module. It is based on the high-performance micro-processor-S3C4510B with the 32/16 bit RISC ARM7TDMI core. The module is used the free uClinux as its OS, which support multi-task, FTP and TELNET functions. It can be used to transfer the mass data from Ethernet to RS485 and build the high speed DCS. (authors)

  16. Arabidopsis ATG4 cysteine proteases specificity toward ATG8 substrates

    Science.gov (United States)

    Park, Eunsook; Woo, Jongchan; Dinesh-Kumar, SP

    2014-01-01

    Macroautophagy (hereafter autophagy) is a regulated intracellular process during which cytoplasmic cargo engulfed by double-membrane autophagosomes is delivered to the vacuole or lysosome for degradation and recycling. Atg8 that is conjugated to phosphatidylethanolamine (PE) during autophagy plays an important role not only in autophagosome biogenesis but also in cargo recruitment. Conjugation of PE to Atg8 requires processing of the C-terminal conserved glycine residue in Atg8 by the Atg4 cysteine protease. The Arabidopsis plant genome contains 9 Atg8 (AtATG8a to AtATG8i) and 2 Atg4 (AtATG4a and AtATG4b) family members. To understand AtATG4’s specificity toward different AtATG8 substrates, we generated a unique synthetic substrate C-AtATG8-ShR (citrine-AtATG8-Renilla luciferase SuperhRLUC). In vitro analyses indicated that AtATG4a is catalytically more active and has broad AtATG8 substrate specificity compared with AtATG4b. Arabidopsis transgenic plants expressing the synthetic substrate C-AtAtg8a-ShR is efficiently processed by endogenous AtATG4s and targeted to the vacuole during nitrogen starvation. These results indicate that the synthetic substrate mimics endogenous AtATG8, and its processing can be monitored in vivo by a bioluminescence resonance energy transfer (BRET) assay. The synthetic Atg8 substrates provide an easy and versatile method to study plant autophagy during different biological processes. PMID:24658121

  17. Metabolism of cysteine and cysteinesulfinate in rat kidney tubules

    International Nuclear Information System (INIS)

    De La Rosa, J.; Stipanuk, M.H.

    1986-01-01

    In studies with rat hepatocytes, hypotaurine plus taurine production accounted for less than 5% of the total amount of cysteine (CYS) catabolized, whereas more than 90% of the metabolized cysteinesulfinate (CSA) was converted to taurine plus hypotaurine. Similar studies have been carried out with kidney tubules isolated from fed rats and incubated with 2 mM [1- 14 C]CYS or 25 mM [1- 14 C]CSA at 37 0 C for up to 40 min. The production of 14 CO 2 from CSA (3.1 +/- 1.3 nmol/sup ./ min -1 /sup ./ mg dry wt -1 ) was equivalent to the accumulation of N in NH 4 + plus glutamate. Substantial oxidation of CYS was observed (16 +/- 11 nmol CO 2 x min -1 x mg dry wt -1 ), but only 12% of the expected amount of N was recovered as NH 4 + plus glutamate. Accumulation of hypotaurine plus taurine was equivalent to 20% of the observed rate of 14 CO 2 production from CSA but accounted for only 2% of the observed rate of 14 CO 2 production from CYS. Addition of unlabeled CSA to incubations with varying levels of CYS had no effect on production of 14 CO 2 . Addition of 2 mM α-ketoglutarate to the incubation mixtures resulted in an increased in 14 CO 2 production from CSA to 290% of the control level but had no effect on CYS oxidation. In agreement with the authors findings for rat hepatocytes, these data suggest that most metabolism of CYS by the rat kidney tubule occurs by a CSA-independent pathway. However, in contrast to the metabolism of CSA almost entirely to taurine in the hepatocyte, kidney tubules appeared to metabolize CSA primarily by the transamination pathway

  18. The Variation Analysis of DNA Methylation in Wheat Carrying Gametocidal Chromosome 3C from Aegilops triuncialis.

    Science.gov (United States)

    Wang, Dan; Zhao, Jieyu; Bai, Yan; Ao, You; Guo, Changhong

    2017-08-10

    Gametocidal (Gc) chromosomes can ensure their preferential transmission by killing the gametes without themselves through causing chromosome breakage and therefore have been exploited as an effective tool for genetic breeding. However, to date very little is known about the molecular mechanism of Gc action. In this study, we used methylation-sensitive amplified polymorphism (MSAP) technique to assess the extent and pattern of cytosine methylation alterations at the whole genome level between two lines of wheat Gc addition line and their common wheat parent. The results indicated that the overall levels of cytosine methylation of two studied Gc addition lines (CS-3C and CS-3C3C, 48.68% and 48.65%, respectively) were significantly increased when compared to common wheat CS (41.31%) and no matter fully methylated or hemimethylated rates enhanced in Gc addition lines. A set of 30 isolated fragments that showed different DNA methylation or demethylation patterns between the three lines were sequenced and the results indicated that 8 fragments showed significant homology to known sequences, of which three were homologous to MITE transposon (Miniature inverted-repeat transposable elements), LTR-retrotransposon WIS-1p and retrotransposon Gypsy , respectively. Overall, our results showed that DNA methylation could play a role in the Gc action.

  19. The Variation Analysis of DNA Methylation in Wheat Carrying Gametocidal Chromosome 3C from Aegilops triuncialis

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2017-08-01

    Full Text Available Gametocidal (Gc chromosomes can ensure their preferential transmission by killing the gametes without themselves through causing chromosome breakage and therefore have been exploited as an effective tool for genetic breeding. However, to date very little is known about the molecular mechanism of Gc action. In this study, we used methylation-sensitive amplified polymorphism (MSAP technique to assess the extent and pattern of cytosine methylation alterations at the whole genome level between two lines of wheat Gc addition line and their common wheat parent. The results indicated that the overall levels of cytosine methylation of two studied Gc addition lines (CS–3C and CS–3C3C, 48.68% and 48.65%, respectively were significantly increased when compared to common wheat CS (41.31% and no matter fully methylated or hemimethylated rates enhanced in Gc addition lines. A set of 30 isolated fragments that showed different DNA methylation or demethylation patterns between the three lines were sequenced and the results indicated that 8 fragments showed significant homology to known sequences, of which three were homologous to MITE transposon (Miniature inverted–repeat transposable elements, LTR-retrotransposon WIS-1p and retrotransposon Gypsy, respectively. Overall, our results showed that DNA methylation could play a role in the Gc action.

  20. Characterization of a n+3C/n−4H SiC heterojunction diode

    Energy Technology Data Exchange (ETDEWEB)

    Minamisawa, R. A.; Mihaila, A. [Department of Power Electronics, ABB Corporate Research Center, CH-5405 Baden-Dättwil (Switzerland); Farkas, I.; Hsu, C.-W.; Janzén, E. [Semiconductor Materials, IFM, Linköping University, SE-58183 Linköping (Sweden); Teodorescu, V. S. [National Institute of Material Physics, R-077125 Bucharest-Măgurele (Romania); Afanas' ev, V. V. [Semiconductor Physics Laboratory, KU Leuven, 3001 Leuven (Belgium); Rahimo, M. [ABB Semiconductors, Fabrikstrasse 3, CH-5600 Lenzburg (Switzerland)

    2016-04-04

    We report on the fabrication of n + 3C/n-4H SiC heterojunction diodes (HJDs) potentially promising the ultimate thermal stability of the junction. The diodes were systematically analyzed by TEM, X-ray diffraction, AFM, and secondary ion mass spectroscopy, indicating the formation of epitaxial 3C-SiC crystal on top of 4H-SiC substrate with continuous interface, low surface roughness, and up to ∼7 × 10{sup 17 }cm{sup −3} dopant impurity concentration. The conduction band off-set is about 1 V as extracted from CV measurements, while the valence bands of both SiC polytypes are aligned. The HJDs feature opening voltage of 1.65 V, consistent with the barrier height of about 1.5 eV extracted from CV measurement. We finally compare the electrical results of the n + 3C/n-4H SiC heterojunction diodes with those featuring Si and Ge doped anodes in order to evaluate current challenges involved in the fabrication of such devices.

  1. Disorder accumulation and recovery in gold-ion irradiated 3C-SiC

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Weilin; Weber, William J.; Lian, Jie; Kalkhoran, N. M.

    2009-01-12

    A single-crystal 3C-SiC film on the Si/SiO2/Si (SIMOX) substrate was irradiated in different areas at 156 K with Au2+ ions to low fluences. The disorder profiles as a function of dose on both the Si and C sublattices have been determined in situ using a combination of 0.94 MeV D+ Rutherford backscattering spectrometry and nuclear reaction analysis in channeling geometry along the <100>, <110> and <111> axes. The results indicate that for the same damage state, the level of disorder on the Si sublattice in 3C-SiC follows a decreasing order along the <111>, <100> and <110> axes, while that on the C sublattice shows comparable values. Similar levels of Si and C disorder are observed along the <111> axis over the applied dose range. However, the level of C disorder is higher than that of Si disorder along either <100> or <110>. The amount of disorder recovery during thermal annealing processes depends on the sublattice (Si or C) and crystallographic orientation. Room-temperature recovery occurs for both sublattices in 3C-SiC irradiated to a dose of 0.047 dpa or lower. Significant recovery is observed along all directions during thermal annealing at 600 K. The results will be discussed and compared to those for 6H- and 4H-SiC under similar irradiation conditions.

  2. 3C-Silicon Carbide Microresonators for Timing and Frequency Reference

    Directory of Open Access Journals (Sweden)

    Graham S. Wood

    2016-11-01

    Full Text Available In the drive to miniaturise and integrate reference oscillator components, microelectromechanical systems (MEMS resonators are excellent candidates to replace quartz crystals. Silicon is the most utilised resonator structural material due to its associated well-established fabrication processes. However, when operation in harsh environments is required, cubic silicon carbide (3C-SiC is an excellent candidate for use as a structural material, due to its robustness, chemical inertness and high temperature stability. In order to actuate 3C-SiC resonators, electrostatic, electrothermal and piezoelectric methods have been explored. Both electrothermal and piezoelectric actuation can be accomplished with simpler fabrication and lower driving voltages, down to 0.5 V, compared to electrostatic actuation. The vibration amplitude at resonance can be maximised by optimising the design and location of the electrodes. Electrical read out of the resonator can be performed with electrostatic or piezoelectric transduction. Finally, a great deal of research has focused on tuning the resonant frequency of a 3C-SiC resonator by adjusting the DC bias applied to the electrodes, with a higher (up to 160-times tuning range for electrothermal tuning compared to piezoelectric tuning. Electrothermal tuning lowers the frequency, while piezoelectric tuning can be used to raise the frequency.

  3. Improved real-time dosimetry using the radioluminescence signal from Al2O3:C

    International Nuclear Information System (INIS)

    Damkjaer, S.M.S.; Andersen, C.E.; Aznar, M.C.

    2008-01-01

    Carbon-doped aluminum oxide (Al 2 O 3 :C) is a highly sensitive luminescence material for ionizing radiation dosimetry, and it is well established that the optically stimulated luminescence (OSL) signal from Al 2 O 3 :C can be used for absorbed-dose measurements. During irradiation, Al 2 O 3 :C also emits prompt radioluminescence (RL) which allows for real-time dose verification. The RL-signal is not linear in the absorbed dose due to sensitivity changes and the presence of shallow traps. Despite this the signal can be processed to obtain a reliable dose rate signal in real time. Previously a simple algorithm for correcting the RL-signal has been published and here we report two improvements: a better and more stable calibration method which is independent of a reference dose rate and a correction for the effect of the shallow traps. Good agreement was found between reference doses and doses derived from the RL-signal using the new algorithm (the standard deviation of the residuals were ∼2% including phantom positioning errors). The RL-algorithm was found to greatly reduce the influence of shallow traps in the range from 0 to 3 Gy and the RL dose-rate measurements with a time resolution of 0.1 s closely matched dose-rate changes monitored with an ionization chamber

  4. Blue optical continuum associated with a radio knot in 3C346

    Science.gov (United States)

    Dey, Arjun; van Breugel, Wil J. M.

    1994-06-01

    We report the discovery of extremely luminous near-UV continuum emission associated with a bright radio knot in the radio galaxy 3C346 (zeta = 0.162). Photometric measurements from U and r' band images and longslit spectra show a spectral energy distribution that steepens at higher frequencies, with radio and optical spectral indices alphar = -0.37 +/- 0.02 and alphao = -1.8 +/- 0.2, respectively. Based on a comparison of the optical properties of this knot with other known cases of optical emission associated with radio structures, we conclude that the continuum emission is optical synchrotron radiation. Our observations are consistent with the suggestion that 3C346 is a foreshortened FR-II radio galaxy with its radio axis oriented close to the line of sight. The optical and radio emission from the knot appear to be associated with a hotspot (at the end of a jet) on the near side. Finally, our U and r' images of 3C346 provide a striking illustration that the optical morphologies of nearby radio galaxies also depend upon wavelength and that studies of these objects are relevant to the interpretation of the alignment effect seen in the high redshift radio galaxies.

  5. Fe_3C@carbon nanocapsules/expanded graphite as anode materials for lithium ion batteries

    International Nuclear Information System (INIS)

    Huang, You-Guo; Lin, Xi-Le; Zhang, Xiao-Hui; Pan, Qi-Chang; Yan, Zhi-Xiong; Wang, Hong-Qiang; Chen, Jian-Jun; Li, Qing-Yu

    2015-01-01

    ABSTRACT: Fe_3C@carbonnanocapsules(*)/expanded graphite composite was successfully prepared by a new and facile method, including mix of starting materials and heat treatment of the precursor. It is featured by unique 3-D structure, where expanded graphite acts as scaffold to ensure a continuous entity, and Fe_3C particles coated by carbon nanocapsules are embedded intimately. The Fe_3C nanoparticles encased in carbon nanocapsules act as catalyst in the modification of SEI film during the cycles. The interesting 3-D architecture which aligns the conductivity paths in the planar direction with expanded graphite and in the axial direction with carbon nanocapsules minimizes the resistance and enhances the reversible capacity. The prepared composite exhibits a high reversible capacity and excellent rate performance as an anode material for lithium ion batteries. The composite maintains a reversible capacity of 1226.2 mAh/g after 75 cycles at 66 mA/g. When the current density increases to 200 mA/g, the reversible capacity maintains 451.5 mAh/g. The facile synthesis method and excellent electrochemical performances make the composite expected to be one of the most potential anode material for lithium ion batteries.

  6. Recombining plasma in the gamma-ray-emitting mixed-morphology supernova remnant 3C 391

    Energy Technology Data Exchange (ETDEWEB)

    Ergin, T.; Sezer, A. [TUBITAK Space Technologies Research Institute, ODTU Campus, 06531 Ankara (Turkey); Saha, L.; Majumdar, P.; Chatterjee, A. [Saha Institute of Nuclear Physics, Kolkata, West Bengal 700064 (India); Bayirli, A.; Ercan, E. N., E-mail: tulun.ergin@tubitak.gov.tr [Physics Department, Bogazici University, Bebek, 34342 Istanbul (Turkey)

    2014-07-20

    A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs) interacting with molecular clouds (MCs) has been discovered to be strong GeV gamma-ray emitters by the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope (Fermi-LAT). The recent observations of the Suzaku X-ray satellite have revealed that some of these interacting gamma-ray-emitting SNRs, such as IC443, W49B, W44, and G359.1-0.5, have overionized plasmas. 3C 391 (G31.9+0.0) is another Galactic MM SNR interacting with MCs. It was observed in GeV gamma rays by Fermi-LAT as well as in the 0.3-10.0 keV X-ray band by Suzaku. In this work, 3C 391 was detected in GeV gamma rays with a significance of ∼18σ and we showed that the GeV emission is point-like in nature. The GeV gamma-ray spectrum was shown to be best explained by the decay of neutral pions assuming that the protons follow a broken power-law distribution. We revealed radiative recombination structures of silicon and sulfur from 3C 391 using Suzaku data. In this paper, we discuss the possible origin of this type of radiative plasma and hadronic gamma rays.

  7. Feline Coronavirus 3c Protein: A Candidate for a Virulence Marker?

    Directory of Open Access Journals (Sweden)

    A. S. Hora

    2016-01-01

    Full Text Available Feline infectious peritonitis virus (FIPV is highly virulent and responsible for the highly fatal disease feline infectious peritonitis (FIP, whereas feline enteric coronavirus (FECV is widespread among the feline population and typically causes asymptomatic infections. Some candidates for genetic markers capable of differentiating these two pathotypes of a unique virus (feline coronavirus have been proposed by several studies. In the present survey, in order to search for markers that can differentiate FECV and FIPV, several clones of the 3a–c, E, and M genes were sequenced from samples obtained from cats with or without FIP. All genes showed genetic diversity and suggested the presence of FCoV mutant spectrum capable of producing a virulent pathotype in an individual-specific way. In addition, all the feline coronavirus FIPV strains demonstrated a truncated 3c protein, and the 3c gene was the only observed pathotypic marker for FCoVs, showing that 3c gene is a candidate marker for the distinction between the two pathotypes when the mutant spectrum is taken into account.

  8. Preparation, Crystallization and X-ray Diffraction Analysis to 1.5 A Resolution of Rat Cysteine Dioxygenase, a Mononuclear Iron Enzyme Responsible for Cysteine Thiol Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Simmons,C.; Hao, Q.; Stipanuk, M.

    2005-01-01

    Cysteine dioxygenase (CDO; EC 1.13.11.20) is an {approx}23 kDa non-heme iron metalloenzyme that is responsible for the oxidation of cysteine by O2, yielding cysteinesulfinate. CDO catalyzes the first step in the conversion of cysteine to taurine, as well as the first step in the catabolism of cysteine to pyruvate plus sulfate. Recombinant rat CDO was heterologously expressed, purified and crystallized. The protein was expressed as a fusion protein bearing a polyhistidine tag to facilitate purification, a thioredoxin tag to improve solubility and a factor Xa cleavage site to permit removal of the entire N-terminus, leaving only the 200 amino acids inherent to the native protein. A multi-step purification scheme was used to achieve >95% purity of CDO. The optimal CDO crystals diffracted to 1.5 Angstroms resolution and belonged to space group P4{sub 3}2{sub 1}2 or P4{sub 1}2{sub 1}2, with unit-cell parameters a = b = 57.55, c = 123.06 Angstrom, {alpha} = {beta} = {gamma} = 90. CDO shows little homology to any other proteins; therefore, the structure of the enzyme will be determined by ab initio phasing using a selenomethionyl derivative.

  9. Test results for the Oasis 3C high performance water-pumping windmill

    Energy Technology Data Exchange (ETDEWEB)

    Eggleston, D.M. [DME Engineering, Midland, TX (United States)

    1997-12-31

    The WINDTech International, L.L.C. Oasis 3C, a 3 m diameter, high-performance water-pumping windmill, was tested at the DME Engineering Wind Test Site just south of Midland, Texas from August through December, 1996. This machine utilizes a 3:1 gearbox with rotating counterweights, similar to a conventional oilfield pumping unit, driven by a multibladed rotor. The rotating counterweight system balances most of the pumping loads and reduces gear loads and starting torque by a factor of at least two and often by a factor of four or more. The torque reduction substantially extends gear and bearing life, and reduces wind speeds required for starting by 30 to 50% or more. The O3C was tested pumping from a quiescent fluid depth of 12.2 m (40 ft) from a 28.3 m (93 ft)-deep well, with additional pumping depth simulated using a pressure regulator valve system. A 9.53 cm (3.75 in.) diameter Harbison-Fischer seal-less single-acting piston pump was used to eliminate pump seal friction as a variable, and standard O3C stroke lengths of 30.5 and 15.2 cm (12 and 6 inches) were used. The regulator spring was set to give a maximum stroke rate of 33 strokes per minute. The water pumped was returned to the well after flowing through a settling tank. The tests were performed in accordance with AWEA WECS testing standards. Instrumentation provided 16 channels of data to accurately measure machine performance, including starting wind speeds, flow rates, O3C azimuth, tail furl angle, wind direction tracking errors, RPM, sucker rod loads, and other variables. The most significant performance data is summarized herein. A mathematical model of machine performance was developed that fairly accurately predicts performance for each of three test conditions. The results verify that the O3C is capable of pumping water at wind speeds from 30% to more than 50% lower than comparable un-counterbalanced units.

  10. Evaluation of the Effects of S-Allyl-L-cysteine, S-Methyl-L-cysteine, trans-S-1-Propenyl-L-cysteine, and Their N-Acetylated and S-Oxidized Metabolites on Human CYP Activities.

    Science.gov (United States)

    Amano, Hirotaka; Kazamori, Daichi; Itoh, Kenji

    2016-01-01

    Three major organosulfur compounds of aged garlic extract, S-allyl-L-cysteine (SAC), S-methyl-L-cysteine (SMC), and trans-S-1-propenyl-L-cysteine (S1PC), were examined for their effects on the activities of five major isoforms of human CYP enzymes: CYP1A2, 2C9, 2C19, 2D6, and 3A4. The metabolite formation from probe substrates for the CYP isoforms was examined in human liver microsomes in the presence of organosulfur compounds at 0.01-1 mM by using liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Allicin, a major component of garlic, inhibited CYP1A2 and CYP3A4 activity by 21-45% at 0.03 mM. In contrast, a CYP2C9-catalyzed reaction was enhanced by up to 1.9 times in the presence of allicin at 0.003-0.3 mM. SAC, SMC, and S1PC had no effect on the activities of the five isoforms, except that S1PC inhibited CYP3A4-catalyzed midazolam 1'-hydroxylation by 31% at 1 mM. The N-acetylated metabolites of the three compounds inhibited the activities of several isoforms to a varying degree at 1 mM. N-Acetyl-S-allyl-L-cysteine and N-acetyl-S-methyl-L-cysteine inhibited the reactions catalyzed by CYP2D6 and CYP1A2, by 19 and 26%, respectively, whereas trans-N-acetyl-S-1-propenyl-L-cysteine showed weak to moderate inhibition (19-49%) of CYP1A2, 2C19, 2D6, and 3A4 activities. On the other hand, both the N-acetylated and S-oxidized metabolites of SAC, SMC, and S1PC had little effect on the reactions catalyzed by the five isoforms. These results indicated that SAC, SMC, and S1PC have little potential to cause drug-drug interaction due to CYP inhibition or activation in vivo, as judged by their minimal effects (IC 50 >1 mM) on the activities of five major isoforms of human CYP in vitro.

  11. On the interplay between Si(110) epilayer atomic roughness and subsequent 3C-SiC growth direction

    Science.gov (United States)

    Khazaka, Rami; Michaud, Jean-François; Vennéguès, Philippe; Nguyen, Luan; Alquier, Daniel; Portail, Marc

    2016-11-01

    In this contribution, we performed the growth of a 3C-SiC/Si/3C-SiC layer stack on a Si(001) substrate by means of chemical vapor deposition. We show that, by tuning the growth conditions, the 3C-SiC epilayer can be grown along either the [111] direction or the [110] direction. The key parameter for the growth of the desired 3C-SiC orientation on the Si(110)/3C-SiC(001)/Si(001) heterostructure is highlighted and is linked to the Si epilayer surface morphology. The epitaxial relation between the layers has been identified using X-ray diffraction and transmission electron microscopy (TEM). We showed that, regardless of the top 3C-SiC epilayer orientation, domains rotated by 90° around the growth direction are present in the epilayer. Furthermore, the difference between the two 3C-SiC orientations was investigated by means of high magnification TEM. The results indicate that the faceted Si(110) epilayer surface morphology results in a (110)-oriented 3C-SiC epilayer, whereas a flat hetero-interface has been observed between 3C-SiC(111) and Si(110). The control of the top 3C-SiC growth direction can be advantageous for the development of new micro-electro-mechanical systems.

  12. Aggregation mechanism of Pd nanoparticles in L-cysteine aqueous solution studied by NEXAFS and AFM

    International Nuclear Information System (INIS)

    Tsukada, C.; Ogawa, S.; Mizutani, T.; Kutluk, G.; Namatame, H.; Taniguchi, M.; Yagi, S.

    2012-01-01

    Highlight: ► We focus on the biocompatibility of Pd nanoparticles (NPs) for L-cysteine under water environment. ► The Pd NPs have been fabricated and deposited on Si wafer by gas evaporation method. ► When the Pd NPs/Si has been dipped into L-cysteine aqueous solution, the L-cysteine has selectively adsorbed on Pd NPs surface and existed as the L-cysteine thiolate, atomic S and L-cystine. ► Moreover, the aggregation of Pd NPs occurs by the migration of Pd NPs on Si and the cross-linked reaction between L-cysteine thiolate molecules adsorbed on Pd NPs. - Abstract: We focus on the biocompatibility of Pd nanoparticles (NPs) from the point of microscopic view. Thus, as the basic research for the biocompatibility, we have investigated the adsorbates on the Pd NPs surface and the aggregation mechanism for the Pd NPs on Si substrate after dipping into L-cysteine aqueous solution by means of NEXAFS measurement and AFM observation. The Pd NPs have been fabricated and deposited on the Si wafer by the gas evaporation method. Judging from the results of NEXAFS measurement, it is clear that the L-cysteine thiolate and atomic S exist on the Pd NPs surface. The results of AFM observation show that the Pd NPs aggregate. It is thought that the aggregation of the Pd NPs occurs by both the migration of the Pd NPs on Si wafer and the cross-linked reaction.

  13. Activation of human acid sphingomyelinase through modification or deletion of C-terminal cysteine.

    Science.gov (United States)

    Qiu, Huawei; Edmunds, Tim; Baker-Malcolm, Jennifer; Karey, Kenneth P; Estes, Scott; Schwarz, Cordula; Hughes, Heather; Van Patten, Scott M

    2003-08-29

    One form of Niemann-Pick disease is caused by a deficiency in the enzymatic activity of acid sphingomyelinase. During efforts to develop an enzyme replacement therapy based on a recombinant form of human acid sphingomyelinase (rhASM), purified preparations of the recombinant enzyme were found to have substantially increased specific activity if cell harvest media were stored for several weeks at -20 degrees C prior to purification. This increase in activity was found to correlate with the loss of the single free thiol on rhASM, suggesting the involvement of a cysteine residue. It was demonstrated that a variety of chemical modifications of the free cysteine on rhASM all result in substantial activation of the enzyme, and the modified cysteine responsible for this activation was shown to be the C-terminal residue (Cys629). Activation was also achieved by copper-promoted dimerization of rhASM (via cysteine) and by C-terminal truncation using carboxypeptidase Y. The role of the C-terminal cysteine in activation was confirmed by creating mutant forms of rhASM in which this residue was either deleted or replaced by a serine, with both forms having substantially higher specific activity than wild-type rhASM. These results indicate that purified rhASM can be activated in vitro by loss of the free thiol on the C-terminal cysteine via chemical modification, dimerization, or deletion of this amino acid residue. This method of activation is similar to the cysteine switch mechanism described previously for matrix metalloproteinases and could represent a means of posttranslational regulation of ASM activity in vivo.

  14. L-Cysteine Production in Escherichia coli Based on Rational Metabolic Engineering and Modular Strategy.

    Science.gov (United States)

    Liu, Han; Fang, Guochen; Wu, Hui; Li, Zhimin; Ye, Qin

    2018-05-01

    L-cysteine is an amino acid with important physiological functions and has a wide range of applications in medicine, food, animal feed, and cosmetics industry. In this study, the L-cysteine synthesis in Escherichia coliEscherichia coli is divided into four modules: the transport module, sulfur module, precursor module, and degradation module. The engineered strain LH03 (overexpression of the feedback-insensitive cysE and the exporter ydeD in JM109) accumulated 45.8 mg L -1 of L-cysteine in 48 hr with yield of 0.4% g/g glucose. Further modifications of strains and culture conditions which based on the rational metabolic engineering and modular strategy improved the L-cysteine biosynthesis significantly. The engineered strain LH06 (with additional overexpression of serA, serC, and serB and double mutant of tnaA and sdaA in LH03) produced 620.9 mg L -1 of L-cysteine with yield of 6.0% g/g glucose, which increased the production by 12 times and the yield by 14 times more than those of LH03 in the original condition. In fed-batch fermentation performed in a 5-L reactor, the concentration of L-cysteine achieved 5.1 g L -1 in 32 hr. This work demonstrates that the combination of rational metabolic engineering and module strategy is a promising approach for increasing the L-cysteine production in E. coli. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Dietary L-cysteine improves the antioxidative potential and lipid metabolism in rats fed a normal diet.

    Science.gov (United States)

    Lee, Seulki; Han, Kyu-Ho; Nakamura, Yumi; Kawakami, Sakura; Shimada, Ken-ichiro; Hayakawa, Touru; Onoue, Hirotake; Fukushima, Michihiro

    2013-01-01

    L-cysteine works as a precursor of the antioxidant, glutathione. We investigated the effects of L-cysteine (1% and 2%) on lipid metabolism and the antioxidative system in rats fed a normal diet. Administering L-cysteine dependently decreased the food intake, fat mass weight and body weight dose. Dietary L-cysteine also decreased the triglyceride levels in the serum and liver. However, there were no significant differences in the hepatic TBARS and glutathione (GSH) levels among the groups. The activities of catalase and glutathione reductase in the rats receiving 2% L-cysteine were significantly higher (pL-cysteine dose-dependently affected the antioxidative enzyme activities, and the lipid levels in the serum and liver which might be related to the reduced food intake.

  16. Characterization of the gene encoding serine acetyltransferase, a regulated enzyme of cysteine biosynthesis from the protist parasites Entamoeba histolytica and Entamoeba dispar. Regulation and possible function of the cysteine biosynthetic pathway in Entamoeba.

    Science.gov (United States)

    Nozaki, T; Asai, T; Sanchez, L B; Kobayashi, S; Nakazawa, M; Takeuchi, T

    1999-11-05

    The enteric protist parasites Entamoeba histolytica and Entamoeba dispar possess a cysteine biosynthetic pathway, unlike their mammalian host, and are capable of de novo production of L-cysteine. We cloned and characterized cDNAs that encode the regulated enzyme serine acetyltransferase (SAT) in this pathway from these amoebae by genetic complementation of a cysteine-auxotrophic Escherichia coli strain with the amoebic cDNA libraries. The deduced amino acid sequences of the amoebic SATs exhibited, within the most conserved region, 36-52% identities with the bacterial and plant SATs. The amoebic SATs contain a unique insertion of eight amino acids, also found in the corresponding region of a plasmid-encoded SAT from Synechococcus sp., which showed the highest overall identities to the amoebic SATs. Phylogenetic reconstruction also revealed a close kinship of the amoebic SATs with cyanobacterial SATs. Biochemical characterization of the recombinant E. histolytica SAT revealed several enzymatic features that distinguished the amoebic enzyme from the bacterial and plant enzymes: 1) inhibition by L-cysteine in a competitive manner with L-serine; 2) inhibition by L-cystine; and 3) no association with cysteine synthase. Genetically engineered amoeba strains that overproduced cysteine synthase and SAT were created. The cysteine synthase-overproducing amoebae had a higher level of cysteine synthase activity and total thiol content and revealed increased resistance to hydrogen peroxide. These results indicate that the cysteine biosynthetic pathway plays an important role in antioxidative defense of these enteric parasites.

  17. 75 FR 10026 - Proposed Collection; Comment Request for Forms W-2, W-2c, W-2AS, W-2GU, W-2VI, W-3, W-3c, W-3cPR...

    Science.gov (United States)

    2010-03-04

    ... W-2, W-2c, W-2AS, W-2GU, W-2VI, W-3, W-3c, W-3cPR, W-3PR, and W-3SS AGENCY: Internal Revenue Service....C. 3506(c)(2)(A)). Currently, the IRS is soliciting comments concerning Forms W-2, W-2c, W-2AS, W-2GU, W-2VI, W-3, W-3c, W- 3cPR, W-3PR, and W-3SS. DATES: Written comments should be received on or...

  18. The effect of L-cysteine on the portion-selective uptake of cadmium in the renal proximal tubule

    International Nuclear Information System (INIS)

    Murakami, Masataka; Sano, Kenichi; Webb, M.

    1987-01-01

    Cadmium (Cd), co-administered with an excess of L-cysteine, accumulates rapidly in the kidneys of the rat. After subcutaneous (s.c.) injection of 3 μmol CdCl 2 /kg body wt the concentrations of Cd in the blood and kidneys increase with the dose of cysteine over the range 0.06-5.0 mmol/kg body wt. At cysteine doses of less than 1.5 mmol/kg body wt the ratio of the concentrations of Cd in the outer medulla and cortex of the kidney remains the same as that after the injection of Cd alone. This ratio, however, is more than doubled at dose levels of 5-10 mmol cysteine/kg body wt. Hepatic uptake of Cd is unaffected by doses of cysteine below 1.5 mmol/kg body wt but decreases markedly at higher doses. In animals that are dosed simultaneously with 5 mmol cysteine/kg body wt, renal uptake of 109 Cd is known to occur in the straight segments of the proximal tubules. At a dose level of less than 1.5 mmol cysteine/kg body wt the present autoradiographical studies show that 109 Cd is taken up predominantly by the proximal convoluted tubules of the kidney cortex. At the critical dose level (1.5 mmol/kg body wt), cysteine decreases the retention of Cd at the s.c. injection site, but probably has little effect on the distribution of Cd between protein and other carrier molecules in the blood. This distribution, however, is altered at higher cysteine dose levels. It is suggested that, under the latter conditions, stable Cd-cysteine complexes are formed in the blood and are filtered readily through the glomeruli. These complexes are taken up in the kidney at the sites of cysteine reabsorption which, by studies with L-[ 35 S]-cysteine, are identified as the straight segments of the proximal tubules. (orig.)

  19. L-Cysteine and L-AP4 microinjections in the rat caudal ventrolateral medulla decrease arterial blood pressure.

    Science.gov (United States)

    Takemoto, Yumi

    2014-12-01

    The thiol amino acid L-cysteine increases arterial blood pressure (ABP) when injected into the cerebrospinal fluid space in conscious rats, indicating a pressor response to centrally acting L-cysteine. A prior synaptic membrane binding assay suggests that L-cysteine has a strong affinity for the L-2-amino-4-phosphonobutyric acid (L-AP4) binding site. The central action of L-cysteine may be vial-AP4 sensitive receptors. The present study investigated cardiovascular responses to L-cysteine and L-ap4 microinjected into the autonomic area of the caudal ventrolateral medulla (CVLM) where inhibitory neurons regulate ABP via pre-sympathetic vasomotor neurons. Both the injection of L-cysteine and L-AP4 in the CVLM sites identified with L-glutamate produced the same depressor and bradycardic responses in urethane-anesthetized rats. Neither a prior antagonist microinjection of MK801 for the N-methyl-D-aspartate (NMDA) receptor nor CNQX for the non-NMDA receptor attenuated the responses to L-cysteine, but the combination of the two receptor blocking with an additional prior injection abolished the response. In contrast, either receptor blockade alone abolished the response to L-AP4, indicating distinct mechanisms between responses to L-cysteine and L-AP4 in the CVLM. The results indicate that the CVLM is a central active site for L-cysteine's cardiovascular response. Central L-cysteine's action could be independent of the L-AP4 sensitive receptors. Cardiovascular regulation may involve endogenous L-cysteine in the CVLM. Further multidisciplinary examinations are required to elaborate on L-cysteine's functional roles in the CVLM. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Acetaminophen-cysteine adducts during therapeutic dosing and following overdose

    Directory of Open Access Journals (Sweden)

    Judge Bryan S

    2011-03-01

    Full Text Available Abstract Background Acetaminophen-cysteine adducts (APAP-CYS are a specific biomarker of acetaminophen exposure. APAP-CYS concentrations have been described in the setting of acute overdose, and a concentration >1.1 nmol/ml has been suggested as a marker of hepatic injury from acetaminophen overdose in patients with an ALT >1000 IU/L. However, the concentrations of APAP-CYS during therapeutic dosing, in cases of acetaminophen toxicity from repeated dosing and in cases of hepatic injury from non-acetaminophen hepatotoxins have not been well characterized. The objective of this study is to describe APAP-CYS concentrations in these clinical settings as well as to further characterize the concentrations observed following acetaminophen overdose. Methods Samples were collected during three clinical trials in which subjects received 4 g/day of acetaminophen and during an observational study of acetaminophen overdose patients. Trial 1 consisted of non-drinkers who received APAP for 10 days, Trial 2 consisted of moderate drinkers dosed for 10 days and Trial 3 included subjects who chronically abuse alcohol dosed for 5 days. Patients in the observational study were categorized by type of acetaminophen exposure (single or repeated. Serum APAP-CYS was measured using high pressure liquid chromatography with electrochemical detection. Results Trial 1 included 144 samples from 24 subjects; Trial 2 included 182 samples from 91 subjects and Trial 3 included 200 samples from 40 subjects. In addition, we collected samples from 19 subjects with acute acetaminophen ingestion, 7 subjects with repeated acetaminophen exposure and 4 subjects who ingested another hepatotoxin. The mean (SD peak APAP-CYS concentrations for the Trials were: Trial 1- 0.4 (0.20 nmol/ml, Trial 2- 0.1 (0.09 nmol/ml and Trial 3- 0.3 (0.12 nmol/ml. APAP-CYS concentrations varied substantially among the patients with acetaminophen toxicity (0.10 to 27.3 nmol/ml. No subject had detectable APAP

  1. Gammay rays from Penrose powered black holes in centaurus A, 3C 273, and NGC 4151

    International Nuclear Information System (INIS)

    Kafatos, M.; and Laboratory for Astronomy and Solar Physics, NASA Goddard Space Flight Center)

    1980-01-01

    Gamma-ray observations of active galaxies have important consequences for theories of the activity in their nuclei. The observations of Cen A, 3C 273, and NGC 4151 are examined under the assumption that Penrose collision processes in the ergospheres of massive black holes power their nuclei. The observed sharp break in the MeV region of the NGC 4151 spectrum cannot be due to the γ-γ pair production process. We attribute this break to the Penrose Compton scattering (PCS), in which γ-rays escape from the ergosphere as a result of Penrose processes involving electrons and lower energy X-ray photons in the ergosphere of the black hole. The absence of an MeV break in the spectra of Cen A and 3C 273 argues in favor of the Penrose pair production (PPP), in which high-energy pairs (a few GeV in energy) escape as result of Penrose processes involving protons and γ-rays that are present in any hot, optically thin, vertically extended accretion disk. An intrinsic break in the GeV region is predicted for both Cen A and 3C 273 as well as any other PPP powered nucleus.If PPP is important for QSOs and radio galaxies and some Seyferts, powerful radio objects should also be powerful γ-ray objects. Nuclei in which the black hole is spinning slowly would still emit visible light, UV, and X-rays as result of accretion without Penrose processes but would be weak in radio or high-energy γ-rays. Future γ-ray observations should provide clues as to whether this scenario is correct. Besides spectral information at γ-ray frequencies, possible variability at γ-ray frequencies should be searched for

  2. AN HST PROPER-MOTION STUDY OF THE LARGE-SCALE JET OF 3C273

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Eileen T.; Georganopoulos, Markos [University of Maryland Baltimore County, Baltimore, MD 21250 (United States); Sparks, William B. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Anderson, Jay; Marel, Roeland van der; Biretta, John; Chiaberge, Marco; Norman, Colin [Space Telescope Science Institute, Baltimore, MD 21210 (United States); Tony Sohn, Sangmo [Johns Hopkins University, Baltimore, MD 21210 (United States); Perlman, Eric, E-mail: meyer@stsci.edu [Florida Institute of Technology, Melbourne, FL 32901 (United States)

    2016-02-20

    The radio galaxy 3C 273 hosts one of the nearest and best-studied powerful quasar jets. Having been imaged repeatedly by the Hubble Space Telescope (HST) over the past twenty years, it was chosen for an HST program to measure proper motions in the kiloparsec-scale resolved jets of nearby radio-loud active galaxies. The jet in 3C 273 is highly relativistic on sub-parsec scales, with apparent proper motions up to 15c observed by very long baseline interferometry. In contrast, we find that the kiloparsec-scale knots are compatible with being stationary, with a mean speed of −0.2 ± 0.5c over the whole jet. Assuming the knots are packets of moving plasma, an upper limit of 1c implies a bulk Lorentz factor Γ < 2.9. This suggests that the jet has either decelerated significantly by the time it reaches the kiloparsec scale, or that the knots in the jet are standing shock features. The second scenario is incompatible with the inverse Compton off the Cosmic Microwave Background (IC/CMB) model for the X-ray emission of these knots, which requires the knots to be in motion, but IC/CMB is also disfavored in the first scenario due to energetic considerations, in agreement with the recent finding of Meyer and Georganopoulos which ruled out the IC/CMB model for the X-ray emission of 3C 273 via gamma-ray upper limits.

  3. A multifrequency study of the radio structure of 3C10, the remnant of Tycho's supernova

    International Nuclear Information System (INIS)

    Duin, R.M.; Strom, R.G.

    1975-01-01

    Synthesis observations of 3C10 have been made at 6 cm and 50 cm using the Westerbork telescope. Combining these results with earlier 21 cm Westerbork maps, we have made detailed comparisons between the three wavelengths. The total intensity maps are remarkably similar: we find no evidence for changes in the spectral index of small scale features around the rim of the shell-like remnant. On the large scale, however, there appears to be a significant steepening of the spectrum near the center of 3C10. We believe this to be related to the fact that the integrated radio spectrum steepens at low frequencies, and suggest that particles presently near the outer boundary may be accelerated with a relatively flat energy spectrum. Although no linear polarization exceeding about 1% of the total intensity could be detected at 50 cm, at 6 cm the polarized emission is quite smooth, being typically 10% of the total intensity. The position angle distribution of the linear polarization is also smooth, confirming our earlier conclusion that 3C10 is surrounded by an irregular Faraday screen. By comparing our 6 cm map with 2.8 cm and 10.4 cm results we are able to construct a rotation measure map, and confirm that the intrinsic position angles are tangentially aligned, with an average rotation measure of -249 rad m -2 . We conclude that the ordered component of the magnetic field is radially directed, and suggest that the mechanism for producing such a configuration can be found in the Sedov solution for shock waves in a fluid medium. (orig.) [de

  4. Characterisation of the Microstructure of Fe–Al/Cr3C2 Composite Coatings

    Science.gov (United States)

    Liu, Xiaoming; JunhuiDong; Yang, Yuehong; Sun, Changming; Tuo, Ya; Li, Yanwei

    2018-03-01

    An Fe-Al/Cr3C2 composite coating is investigated to assess its suitability for treating high-temperature components in a power plant. The coating exhibits excellent high- temperature properties including good corrosion, erosion and friction-wear resistance at high temperatures. To deduce the formation of the Fe-Al/Cr3C2 composite coating and to provide an adequate theoretical basis for its extensive application, its structures and microstructures are investigated. Scanning electronic microscopy (SEM)is used along with energy-dispersive X-ray analysis (EDAX) to analyse the surface of the coating. Energy-dispersive spectroscopy (EDS) is used to analyse the cross-section of the coating. Further, X-ray diffraction (XRD) and transmission electron microscopy (TEM) are used to analyse the phases and micro structural features within the coating. The results reveal that the basic phases are two orderly inter metallic compounds (Fe3Al and FeAl) and that the reinforcement includes two oxides (Al2O3 and Cr2O3) as well as substantial quantities of Cr3C2. Al2O3is formed using two mechanisms: oxidation of aluminium in the coating and separation of Al2O3crystals from Fe3Al and FeAl. The grain size of Al2O3 and Cr2O3 in the coatings is nanometric. These two oxides may increase the corrosion-erosion and wear resistances of the coating when they are used as reinforcements.

  5. MULTIWAVELENGTH VARIABILITY OF THE BROAD LINE RADIO GALAXY 3C 120

    International Nuclear Information System (INIS)

    Marshall, Kevin; Ryle, Wesley T.; Miller, H. Richard; Marscher, Alan P.; Jorstad, Svetlana G.; Chicka, Benjamin; McHardy, Ian M.

    2009-01-01

    We present results from a multiyear monitoring campaign of the broad-line radio galaxy 3C 120, using the Rossi X-ray Timing Explorer for nearly five years of observations. Additionally, we present coincident optical monitoring using data from several ground-based observatories. Both the X-ray and optical emission are highly variable and appear to be strongly correlated, with the X-ray emission leading the optical by 28 days. The X-ray power density spectrum is best fit by a broken power law, with a low-frequency slope of -1.2, breaking to a high-frequency slope of -2.1, and a break frequency of log ν b = -5.75 Hz, or 6.5 days. This value agrees well with the value expected based on 3C 120's mass and accretion rate. We find no evidence for a second break in the power spectrum. Combined with a moderately soft X-ray spectrum (Γ = 1.8) and a moderately high accretion rate, this indicates that 3C 120 fits in well with the high/soft variability state found in most other active galactic nuclei. Previous studies have shown that the spectrum has a strong Fe Kα line, which may be relativistically broadened. The presence of this line, combined with a power spectrum similar to that seen in Seyfert galaxies, suggests that the majority of the X-ray emission in this object arises in or near the disk, and not in the jet.

  6. 3C-SiC nanocrystal growth on 10° miscut Si(001) surface

    Energy Technology Data Exchange (ETDEWEB)

    Deokar, Geetanjali, E-mail: gitudeo@gmail.com [INSP, UPMC, CNRS UMR 7588, 4 place Jussieu, Paris F-75005 (France); D' Angelo, Marie; Demaille, Dominique [INSP, UPMC, CNRS UMR 7588, 4 place Jussieu, Paris F-75005 (France); Cavellin, Catherine Deville [INSP, UPMC, CNRS UMR 7588, 4 place Jussieu, Paris F-75005 (France); Faculté des Sciences et Technologie UPEC, 61 av. De Gaulle, Créteil F-94010 (France)

    2014-04-01

    The growth of 3C-SiC nano-crystal (NC) on 10° miscut Si(001) substrate by CO{sub 2} thermal treatment is investigated by scanning and high resolution transmission electron microscopies. The vicinal Si(001) surface was thermally oxidized prior to the annealing at 1100 °C under CO{sub 2} atmosphere. The influence of the atomic steps at the vicinal SiO{sub 2}/Si interface on the SiC NC growth is studied by comparison with the results obtained for fundamental Si(001) substrates in the same conditions. For Si miscut substrate, a substantial enhancement in the density of the SiC NCs and a tendency of preferential alignment of them along the atomic step edges is observed. The SiC/Si interface is abrupt, without any steps and epitaxial growth with full relaxation of 3C-SiC occurs by domain matching epitaxy. The CO{sub 2} pressure and annealing time effect on NC growth is analyzed. The as-prepared SiC NCs can be engineered further for potential application in optoelectronic devices and/or as a seed for homoepitaxial SiC or heteroepitaxial GaN film growth. - Highlights: • Synthesis of 3C-SiC nanocrystals epitaxied on miscut-Si using a simple technique • Evidence of domain matching epitaxy at the SiC/Si interface • SiC growth proceeds along the (001) plane of host Si. • Substantial enhancement of the SiC nanocrystal density due to the miscut • Effect of the process parameters (CO{sub 2} pressure and annealing duration)

  7. Experimental and theoretical investigation on corrosion inhibition of AA5052 aluminium alloy by L-cysteine in alkaline solution

    International Nuclear Information System (INIS)

    Wang, Dapeng; Gao, Lixin; Zhang, Daquan; Yang, Dong; Wang, Hongxia; Lin, Tong

    2016-01-01

    The corrosion inhibition of L-cysteine on AA5052 aluminium alloy in 4 mol/L NaOH solution was investigated by hydrogen gas evolution experiment, polarisation curve, galvanostatic discharge, electrochemical impedance spectroscopy measurements and quantum chemical calculations. The adsorption of L-cysteine on aluminium alloy surface obeyed the amended Langmuir's adsorption isotherm. The polarisation curves indicated that L-cysteine acted as a cathodic inhibitor to inhibit cathodic reaction. The inhibition mechanism was dominated by the geometric covering effect. The galvanostatic discharge shows that the additives restrain the hydrogen evolution and increase the anodic utilization rate. Quantum chemical calculations indicated that L-cysteine molecules mainly interacted with on the carboxyl groups on the aluminium alloy surface. A strong hybridization occurred between the s-orbital and p-orbital of reactive sites in the L-cysteine molecule and the sp-orbital of Aluminium. - Highlights: • L-cysteine was used as corrosion inhibitor for Al alloy in alkaline solution. • Adsorption of L-cysteine on Al alloy surface obeyed the amended Langmuir's isotherm. • L-cysteine molecules interacted with the carboxyl groups on the Al alloy surface. • A strong orbital hybridization occurred between the reactive sites in L-cysteine and Al.

  8. Pressor response to L-cysteine injected into the cisterna magna of conscious rats involves recruitment of hypothalamic vasopressinergic neurons.

    Science.gov (United States)

    Takemoto, Yumi

    2013-03-01

    The sulfur-containing non-essential amino acid L-cysteine injected into the cisterna magna of adult conscious rats produces an increase in blood pressure. The present study examined if the pressor response to L-cysteine is stereospecific and involves recruitment of hypothalamic vasopressinergic neurons and medullary noradrenergic A1 neurons. Intracisternally injected D-cysteine produced no cardiovascular changes, while L-cysteine produced hypertension and tachycardia in freely moving rats, indicating the stereospecific hemodynamic actions of L-cysteine via the brain. The double labeling immunohistochemistry combined with c-Fos detection as a marker of neuronal activation revealed significantly higher numbers of c-Fos-positive vasopressinergic neurons both in the supraoptic and paraventricular nuclei and tyrosine hydroxylase containing medullary A1 neurons, of L-cysteine-injected rats than those injected with D-cysteine as iso-osmotic control. The results indicate that the cardiovascular responses to intracisternal injection of L-cysteine in the conscious rat are stereospecific and include recruitment of hypothalamic vasopressinergic neurons both in the supraoptic and paraventricular nuclei, as well as of medullary A1 neurons. The findings may suggest a potential function of L-cysteine as an extracellular signal such as neuromodulators in central regulation of blood pressure.

  9. Experimental and theoretical investigation on corrosion inhibition of AA5052 aluminium alloy by L-cysteine in alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dapeng; Gao, Lixin [School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Zhang, Daquan, E-mail: zhangdaquan@shiep.edu.cn [School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Yang, Dong [School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Wang, Hongxia; Lin, Tong [Institute for Frontier Materials, Deakin University, Geelong, VIC 3216 (Australia)

    2016-02-01

    The corrosion inhibition of L-cysteine on AA5052 aluminium alloy in 4 mol/L NaOH solution was investigated by hydrogen gas evolution experiment, polarisation curve, galvanostatic discharge, electrochemical impedance spectroscopy measurements and quantum chemical calculations. The adsorption of L-cysteine on aluminium alloy surface obeyed the amended Langmuir's adsorption isotherm. The polarisation curves indicated that L-cysteine acted as a cathodic inhibitor to inhibit cathodic reaction. The inhibition mechanism was dominated by the geometric covering effect. The galvanostatic discharge shows that the additives restrain the hydrogen evolution and increase the anodic utilization rate. Quantum chemical calculations indicated that L-cysteine molecules mainly interacted with on the carboxyl groups on the aluminium alloy surface. A strong hybridization occurred between the s-orbital and p-orbital of reactive sites in the L-cysteine molecule and the sp-orbital of Aluminium. - Highlights: • L-cysteine was used as corrosion inhibitor for Al alloy in alkaline solution. • Adsorption of L-cysteine on Al alloy surface obeyed the amended Langmuir's isotherm. • L-cysteine molecules interacted with the carboxyl groups on the Al alloy surface. • A strong orbital hybridization occurred between the reactive sites in L-cysteine and Al.

  10. Fasting, but Not Aging, Dramatically Alters the Redox Status of Cysteine Residues on Proteins in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Katja E. Menger

    2015-06-01

    Full Text Available Altering the redox state of cysteine residues on protein surfaces is an important response to environmental challenges. Although aging and fasting alter many redox processes, the role of cysteine residues is uncertain. To address this, we used a redox proteomic technique, oxidative isotope-coded affinity tags (OxICAT, to assess cysteine-residue redox changes in Drosophila melanogaster during aging and fasting. This approach enabled us to simultaneously identify and quantify the redox state of several hundred cysteine residues in vivo. Cysteine residues within young flies had a bimodal distribution with peaks at ∼10% and ∼85% reversibly oxidized. Surprisingly, these cysteine residues did not become more oxidized with age. In contrast, 24 hr of fasting dramatically oxidized cysteine residues that were reduced under fed conditions while also reducing cysteine residues that were initially oxidized. We conclude that fasting, but not aging, dramatically alters cysteine-residue redox status in D. melanogaster.

  11. Optical synchrotron emission in the southern lobe of 3C33

    Energy Technology Data Exchange (ETDEWEB)

    Meisenheimer, K; Roeser, H -J

    1986-02-06

    Charge coupled device polarimetry at a wavelength of 660 nm has detected a highly-polarized optical source, which is coincident with the radio hotspot at the leading edge of the southern lobe of 3C33. The optical polarization data perfectly match the high-frequency Very Large Array observations, thus providing the first direct evidence for optical synchrotron radiation from a classic double radio source. The extended structure of the emission region requires a huge particle accelerator boosting electrons to highly relativistic energies (up to 100 GeV) over a region several kiloparsecs in extent.

  12. Galactic-scale Feedback Observed in the 3C 298 Quasar Host Galaxy

    Science.gov (United States)

    Vayner, Andrey; Wright, Shelley A.; Murray, Norman; Armus, Lee; Larkin, James E.; Mieda, Etsuko

    2017-12-01

    We present high angular resolution multiwavelength data of the 3C 298 radio-loud quasar host galaxy (z = 1.439) taken using the W.M. Keck Observatory OSIRIS integral field spectrograph (IFS) with adaptive optics, the Atacama Large Millimeter/submillimeter Array (ALMA), the Hubble Space Telescope (HST) WFC3, and the Very Large Array (VLA). Extended emission is detected in the rest-frame optical nebular emission lines Hβ, [O III], Hα, [N II], and [S II], as well as in the molecular lines CO (J = 3‑2) and (J = 5‑4). Along the path of the relativistic jets of 3C 298, we detect conical outflows in ionized gas emission with velocities of up to 1700 {km} {{{s}}}-1 and an outflow rate of 450–1500 {M}ȯ {{yr}}-1 extended over 12 kpc. Near the spatial center of the conical outflow, CO (J = 3‑2) emission shows a molecular gas disk with a rotational velocity of ±150 {km} {{{s}}}-1 and total molecular mass ({M}{{{H}}2}) of 6.6+/- 0.36× {10}9 {M}ȯ . On the blueshifted side of the molecular disk, we observe broad extended emission that is due to a molecular outflow with a rate of 2300 {M}ȯ {{yr}}-1 and depletion timescale of 3 Myr. We detect no narrow Hα emission in the outflow regions, suggesting a limit on star formation of 0.3 {M}ȯ {{yr}}-1 {{kpc}}-2. Quasar-driven winds are evacuating the molecular gas reservoir, thereby directly impacting star formation in the host galaxy. The observed mass of the supermassive black hole is {10}9.37{--9.56} {M}ȯ , and we determine a dynamical bulge mass of {M}{bulge}=1{--}1.7× {10}10\\tfrac{R}{1.6 {kpc}} {M}ȯ . The bulge mass of 3C 298 lies 2–2.5 orders of magnitude below the expected value from the local galactic bulge—supermassive black hole mass ({M}{bulge}{--}{M}{BH}) relationship. A second galactic disk observed in nebular emission is offset from the quasar by 9 kpc, suggesting that the system is an intermediate-stage merger. These results show that galactic-scale negative feedback is occurring early in the merger

  13. Interplanetary scintillations of the 3C 279 radiosource from RATAN-600 observations

    International Nuclear Information System (INIS)

    Shishova, T.D.; Mingaliev, M.G.; AN SSSR, Nizhnij Arkhyz. Spetsial'naya Astrofizicheskaya Observatoriya)

    1980-01-01

    In 1976 and 1977 observations of interplanetary scintillations of the 3C 279 radiosource were carred out at the RATAN-600 at centimeter wavelengths. At Lambda=3.9 cm the index of scintillations gets suturated at the distance R approximately equal to 4 Rsub(Sun) from the Sun. The estimation of solar wind velocity is approximately 140 km/s at R=5Rsub(Sun); it grows up to approximately 400 km/s at R approximately equal to 10 Rsub(Sun)

  14. Revision of an automated microseismic location algorithm for DAS - 3C geophone hybrid array

    Science.gov (United States)

    Mizuno, T.; LeCalvez, J.; Raymer, D.

    2017-12-01

    Application of distributed acoustic sensing (DAS) has been studied in several areas in seismology. One of the areas is microseismic reservoir monitoring (e.g., Molteni et al., 2017, First Break). Considering the present limitations of DAS, which include relatively low signal-to-noise ratio (SNR) and no 3C polarization measurements, a DAS - 3C geophone hybrid array is a practical option when using a single monitoring well. Considering the large volume of data from distributed sensing, microseismic event detection and location using a source scanning type algorithm is a reasonable choice, especially for real-time monitoring. The algorithm must handle both strain rate along the borehole axis for DAS and particle velocity for 3C geophones. Only a small quantity of large SNR events will be detected throughout a large aperture encompassing the hybrid array; therefore, the aperture is to be optimized dynamically to eliminate noisy channels for a majority of events. For such hybrid array, coalescence microseismic mapping (CMM) (Drew et al., 2005, SPE) was revised. CMM forms a likelihood function of location of event and its origin time. At each receiver, a time function of event arrival likelihood is inferred using an SNR function, and it is migrated to time and space to determine hypocenter and origin time likelihood. This algorithm was revised to dynamically optimize such a hybrid array by identifying receivers where a microseismic signal is possibly detected and using only those receivers to compute the likelihood function. Currently, peak SNR is used to select receivers. To prevent false results due to small aperture, a minimum aperture threshold is employed. The algorithm refines location likelihood using 3C geophone polarization. We tested this algorithm using a ray-based synthetic dataset. Leaney (2014, PhD thesis, UBC) is used to compute particle velocity at receivers. Strain rate along the borehole axis is computed from particle velocity as DAS microseismic

  15. Fermi LAT detection of renewed strong GeV activity from the FSRQ 3C 279

    Science.gov (United States)

    Ojha, Roopesh; van Zyl, Pfesesani; Fermi Large Area Telescope Collaboration

    2018-04-01

    The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope, has observed an intense and hard gamma-ray flare from a source positionally consistent with the flat spectrum radio quasar 3C 279, also known as 3FGL J1256.1-0547 (Acero et al. 2015, ApJS, 218, 23), with radio coordinates R.A.: 12h56m11.1665s, Dec: -05d47m21.523s (J2000.0; Johnston et al. 1995, AJ, 110, 880).

  16. The Physics of AGN, a Deep Understanding of the Quasar 3C 273

    Science.gov (United States)

    Courvoisier, T.; Bottcher, Markus

    2004-01-01

    Upon our successful AO-1 proposal no. 120023, the quasar 3C 273 has been observed with INTEGRAL in 3 epochs in January 2003. The first observation, on January 5, 2003, with a total INTEGRAL exposure of 1.2 x 10(exp 5) s, was simultaneous with RXTE and XMM- Newton observations. Two more INTEGRAL observations were carried out on January 11, 2003 (exposure: lo4 s) and January 17, 2003 (exposure: 1.1 x 10(exp 5) s). The source was detected with high significance by all INTEGRAL instruments, the OMC, JEM-X, SPI, and IBIS/ISGRI. Being one of the first INTEGRAL observations simultaneous with XMM and RXTE, our observations were also used to fix the cross calibration with those instruments. The combined spectrum resulting from the XMM-Newton, JEM-X, RXTE, SPI and ISGRI X-ray / soft gamma-ray observations is consistent with a straight power-law of photon index Gamma = (1.73 +/- 0.015) between 3 keV and at least 200 keV. A possible detection in the 200 keV - 500 keV band by SPI can not be confirmed with our observations. The normalization of the X/gamma-ray spectrum is (2.24 +/- 0.05) x 10(exp -2) photons /sq cm keV at 1 keV. The source showed a moderate amount of optical variability as observed with the OMC onboard INTEGRAL. No evidence for variability at X-rays and gamma-rays could be reported, which may have been a result of insufficient photon statistics. The X-/gamma-ray spectrum observed in our 2003 observations is consistent with previously measured and modelled broadband spectral energy distributions of 3C 273. It has been included in the U.S. lead Col's work on spectral and variability modelling of gamma-ray blazars, supporting the trend of flat-spectrum radio quasars such as 3C 273 being 7-ray dominated due to a strong contribution from Compton upscattering of external radiation by ultrarelativistic electrons in a relativistic jet. 3C 273 is a particularly convincing example for such a picture since it provides very direct evidence for a strong external radiation

  17. S3C: EBT Steady-State Shooting code description and user's guide

    International Nuclear Information System (INIS)

    Downum, W.B.

    1983-09-01

    The Oak Ridge National Laboratory (ORNL) one-dimensional (1-D) Steady-State Shooting code (S3C) for ELMO Bumpy Torus (EBT) plasmas is described. Benchmark calculations finding the steady-state density and electron and ion temperature profiles for a known neutral density profile and known external energy sources are carried out. Good agreement is obtained with results from the ORNL Radially Resolved Time Dependent 1-D Transport code for an EBT-Q type reactor. The program logic is described, along with the physics models in each code block and the variable names used. Sample input and output files are listed, along with the main code

  18. Improved real-time dosimetry using the radioluminescence signal from Al2O3:C

    DEFF Research Database (Denmark)

    Damkjær, Sidsel Marie Skov; Andersen, Claus Erik; Aznar, Marianne

    2008-01-01

    15th International Conference on Solid State Dosimetry Location: Delft Univ Technol, Delft, NETHERLANDS Date: JUL 08-13, 2007 Abstract: Carbon-doped aluminum oxide (Al2O3:C) is a highly sensitive luminescence material for ionizing radiation dosimetry, and it is well established that the optically...... to greatly reduce the influence of shallow traps in the range from 0 to 3 Gy and the RL dose-rate measurements with a time resolution of 0. 1 s closely matched dose-rate changes monitored with in ionization chamber. (c) 2007 Elsevier Ltd. All rights reserved....

  19. Magnetic properties of Fe3C nanograins embedded in carbon matrix

    International Nuclear Information System (INIS)

    Lee, Y.H.; Han, T.C.; Huang, J.C.A.

    2003-01-01

    Magnetron dc cosputtering of a composite target of graphite disk plus iron rods was used in manufacturing carbon films with Fe 3 C nanograin inclusions. Both temperature- and field-dependent magnetizations, M(T) and M(H), were measured for samples of various carbon concentrations (from 37% to 85%). M(T) were measured in both conditions of zero-field cooling and a field cooling at H=100 Oe. Experimental results of χ(T), obtained from M(T), of zero-field cooling, were theoretically fitted by using Wolhfarth's model of noninteracting particles with log-normal distribution function of particle size

  20. An unusual cause of chest pain: Fused cervical vertebra (C3-C4

    Directory of Open Access Journals (Sweden)

    Daipayan Chatterjee

    2014-01-01

    Full Text Available Cervicogenic angina is paroxysmal precordialgia usually due to lower cervical vertebral involvement. But upper cervical vertebral segmental anomaly causing cervicogenic angina is rare. Herein, we report a case of cervicogenic angina due to fused 3 rd and 4 th cervical vertebra in a 37-year female, which was initially misdiagnosed as angina and treated likewise. But, persistence of symptoms led to evaluation of her cervical spine and subsequent diagnosis. Cervical traction, physiotherapy and posture training relieved her of her symptoms with no recurrence till 6 months of follow-up. Fused C3-C4 can be a cause of precordialgia and physicians should be aware of it.

  1. Cysteine-mediated gene expression and characterization of the CmbR regulon in Streptococcus pneumoniae

    Directory of Open Access Journals (Sweden)

    Muhammad Afzal

    2016-12-01

    Full Text Available In this study, we investigated the transcriptomic response of Streptococcus pneumoniae D39 to cysteine. Transcriptome comparison of the D39 wild-type strain grown at a restricted concentration of cysteine (0.03 mM to one grown at a high concentration of cysteine (50 mM in chemically-define medium (CDM revealed elevated expression of various genes/operons, i.e. spd-0150, metQ, spd-0431, metEF, gshT, spd-0618, fhs, tcyB, metB-csd, metA, spd-1898, yvdE, and cysK, likely to be involved in the transport and utilization of cysteine and/or methionine. Microarray-based data were further confirmed by quantitative RT-PCR. Promoter lacZ-fusion studies and quantitative RT-PCR data showed that the transcriptional regulator CmbR acts as a transcriptional repressor of spd-0150, metEF, gshT, spd-0618, tcyB, metA, and yvdE, putatively involved in cysteine uptake and utilization. The operator site of CmbR in the promoter regions of CmbR-regulated genes is predicted and confirmed by mutating or deleting CmbR operator sites from the promoter regions of these genes.

  2. Identification of semicarbazones, thiosemicarbazones and triazine nitriles as inhibitors of Leishmania mexicana cysteine protease CPB.

    Directory of Open Access Journals (Sweden)

    Jörg Schröder

    Full Text Available Cysteine proteases of the papain superfamily are present in nearly all eukaryotes. They play pivotal roles in the biology of parasites and inhibition of cysteine proteases is emerging as an important strategy to combat parasitic diseases such as sleeping sickness, Chagas' disease and leishmaniasis. Homology modeling of the mature Leishmania mexicana cysteine protease CPB2.8 suggested that it differs significantly from bovine cathepsin B and thus could be a good drug target. High throughput screening of a compound library against this enzyme and bovine cathepsin B in a counter assay identified four novel inhibitors, containing the warhead-types semicarbazone, thiosemicarbazone and triazine nitrile, that can be used as leads for antiparasite drug design. Covalent docking experiments confirmed the SARs of these lead compounds in an effort to understand the structural elements required for specific inhibition of CPB2.8. This study has provided starting points for the design of selective and highly potent inhibitors of L. mexicana cysteine protease CPB that may also have useful efficacy against other important cysteine proteases.

  3. Selective chromogenic and fluorogenic peptide substrates for the assay of cysteine peptidases in complex mixtures.

    Science.gov (United States)

    Semashko, Tatiana A; Vorotnikova, Elena A; Sharikova, Valeriya F; Vinokurov, Konstantin S; Smirnova, Yulia A; Dunaevsky, Yakov E; Belozersky, Mikhail A; Oppert, Brenda; Elpidina, Elena N; Filippova, Irina Y

    2014-03-15

    This study describes the design, synthesis, and use of selective peptide substrates for cysteine peptidases of the C1 papain family, important in many biological processes. The structure of the newly synthesized substrates is Glp-Xaa-Ala-Y (where Glp=pyroglutamyl; Xaa=Phe or Val; and Y=pNA [p-nitroanilide], AMC [4-amino-7-methylcoumaride], or AFC [4-amino-7-trifluoromethyl-coumaride]). Substrates were synthesized enzymatically to guarantee selectivity of the reaction and optical purity of the target compounds, simplifying the scheme of synthesis and isolation of products. The hydrolysis of the synthesized substrates was evaluated by C1 cysteine peptidases from different organisms and with different functions, including plant enzymes papain, bromelain, ficin, and mammalian lysosomal cathepsins B and L. The new substrates were selective for C1 cysteine peptidases and were not hydrolyzed by serine, aspartic, or metallo peptidases. We demonstrated an application of the selectivity of the synthesized substrates during the chromatographic separation of a multicomponent set of digestive peptidases from a beetle, Tenebrio molitor. Used in combination with the cysteine peptidase inhibitor E-64, these substrates were able to differentiate cysteine peptidases from peptidases of other classes in midgut extracts from T. molitor larvae and larvae of the genus Tribolium; thus, they are useful in the analysis of complex mixtures containing peptidases from different classes. Published by Elsevier Inc.

  4. Electronic structures of the L-cysteine film on dental alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, K., E-mail: e7141@cc.saga-u.ac.jp [Synchrotron Light Application Center, Saga University, Saga 840-8502 (Japan); Tsujibayashi, T. [Department of Physics, Osaka Dental University, Osaka 573-1121 (Japan); Takahashi, K.; Azuma, J. [Synchrotron Light Application Center, Saga University, Saga 840-8502 (Japan); Kakimoto, K. [Department of Geriatric Dentistry, Osaka Dental University, Osaka 573-1121 (Japan); Kamada, M. [Synchrotron Light Application Center, Saga University, Saga 840-8502 (Japan)

    2011-04-15

    Research highlights: {yields} The electronic structures of dental alloys and L-cysteine film were studied by PES. {yields} The density of states in the dental alloy originates from Au and Cu as constituents. {yields} The Cu-3d states contribute dominantly to the occupied states near the Fermi level. {yields} The electronic structure of L-cysteine thin film is different from the thick film. {yields} The bonding between Cu-3d and S-3sp states are formed at the interface. - Abstract: Metal-organic interfaces have been attracting continuous attention in many fields including basic biosciences. The surface of dental alloys could be one of such interfaces since they are used in a circumstance full of organic compounds such as proteins and bacteria. In this work, electronic structures of Au-dominant dental alloys, which have Ag and Cu besides Au, and those of L-cysteine on the dental alloys have been studied by photoelectron spectroscopy with synchrotron radiation. It was found that the density of states in the dental alloy originate from gold and copper as constituents, and the Cu-3d states contribute dominantly to the occupied states near the Fermi level. It was also found that the electronic structure of the L-cysteine thin film on the dental alloy is different from that of the L-cysteine thick film. The result indicates the formation of the orbital bonding between Cu-3d and S-3sp states in the thin film on the dental alloy.

  5. Cysteine regulation of protein function--as exemplified by NMDA-receptor modulation.

    Science.gov (United States)

    Lipton, Stuart A; Choi, Yun-Beom; Takahashi, Hiroto; Zhang, Dongxian; Li, Weizhong; Godzik, Adam; Bankston, Laurie A

    2002-09-01

    Until recently cysteine residues, especially those located extracellularly, were thought to be important for metal coordination, catalysis and protein structure by forming disulfide bonds - but they were not thought to regulate protein function. However, this is not the case. Crucial cysteine residues can be involved in modulation of protein activity and signaling events via other reactions of their thiol (sulfhydryl; -SH) groups. These reactions can take several forms, such as redox events (chemical reduction or oxidation), chelation of transition metals (chiefly Zn(2+), Mn(2+) and Cu(2+)) or S-nitrosylation [the catalyzed transfer of a nitric oxide (NO) group to a thiol group]. In several cases, these disparate reactions can compete with one another for the same thiol group on a single cysteine residue, forming a molecular switch composed of a latticework of possible redox, NO or Zn(2+) modifications to control protein function. Thiol-mediated regulation of protein function can also involve reactions of cysteine residues that affect ligand binding allosterically. This article reviews the basis for these molecular cysteine switches, drawing on the NMDA receptor as an exemplary protein, and proposes a molecular model for the action of S-nitrosylation based on recently derived crystal structures.

  6. Electronic structures of the L-cysteine film on dental alloys

    International Nuclear Information System (INIS)

    Ogawa, K.; Tsujibayashi, T.; Takahashi, K.; Azuma, J.; Kakimoto, K.; Kamada, M.

    2011-01-01

    Research highlights: → The electronic structures of dental alloys and L-cysteine film were studied by PES. → The density of states in the dental alloy originates from Au and Cu as constituents. → The Cu-3d states contribute dominantly to the occupied states near the Fermi level. → The electronic structure of L-cysteine thin film is different from the thick film. → The bonding between Cu-3d and S-3sp states are formed at the interface. - Abstract: Metal-organic interfaces have been attracting continuous attention in many fields including basic biosciences. The surface of dental alloys could be one of such interfaces since they are used in a circumstance full of organic compounds such as proteins and bacteria. In this work, electronic structures of Au-dominant dental alloys, which have Ag and Cu besides Au, and those of L-cysteine on the dental alloys have been studied by photoelectron spectroscopy with synchrotron radiation. It was found that the density of states in the dental alloy originate from gold and copper as constituents, and the Cu-3d states contribute dominantly to the occupied states near the Fermi level. It was also found that the electronic structure of the L-cysteine thin film on the dental alloy is different from that of the L-cysteine thick film. The result indicates the formation of the orbital bonding between Cu-3d and S-3sp states in the thin film on the dental alloy.

  7. Cysteine proteases: Modes of activation and future prospects as pharmacological targets

    Directory of Open Access Journals (Sweden)

    Sonia eVerma

    2016-04-01

    Full Text Available Proteolytic enzymes are crucial for a variety of biological processes in organisms ranging from lower (virus, bacteria and parasite to the higher organisms (mammals. Proteases cleave proteins into smaller fragments by catalyzing peptide bonds hydrolysis. Proteases are classified according to their catalytic site, and distributed into four major classes: cysteine proteases, serine proteases, aspartic proteases and metallo-proteases. This review will cover only cysteine proteases, papain family enzymes which are involved in multiple functions such as extracellular matrix turnover, antigen presentation, processing events, digestion, immune invasion, hemoglobin hydrolysis, parasite invasion, parasite egress and processing surface proteins. Therefore, they are promising drug targets for various diseases. For preventing unwanted digestion, cysteine proteases are synthesized as zymogens, and contain a pro-domain (regulatory and a mature domain (catalytic. The prodomain acts as an endogenous inhibitor of the mature enzyme. For activation of the mature enzyme, removal of the prodomain is necessary and achieved by different modes. The pro-mature domain interaction can be categorized as protein-protein interactions (PPIs and may be targeted in a range of diseases. Cysteine protease inhibitors are available that can block the active site but no such inhibitor available yet that can be targeted to block the pro-mature domain interactions and prevent it activation. This review specifically highlights the modes of activation (processing of papain family enzymes, which involve auto-activation, trans-activation and also clarifies the future aspects of targeting PPIs to prevent the activation of cysteine proteases.

  8. The effect of cysteine on the corrosion of 304L stainless steel in sulphuric acid

    International Nuclear Information System (INIS)

    Silva, A.B.; Agostinho, S.M.L.; Barcia, O.E.; Cordeiro, G.G.O.; D'Elia, E.

    2006-01-01

    The effect of cysteine on the corrosion of 304L stainless steel in 1 mol l -1 H 2 SO 4 was studied using open-circuit potential measurements, anodic polarization curves, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). All the electrochemical measurements obtained in the presence of low cysteine concentration (10 -6 -10 -5 mol l -1 ) presented the same behaviour as those obtained in the absence of cysteine, a passivated steel surface. However, for higher cysteine concentrations (10 -4 -10 -2 mol l -1 ), a different behaviour was observed: the corrosion potential stabilized at a more negative value; an active region was observed in the anodic polarization curves and the electrochemical impedance diagrams showed an inductive loop at lower frequencies and a much lower polarization resistance. These results show that the presence of cysteine at high concentration turns the surface of 304L stainless steel electrochemically active, probably dissolving the passivation layer and promoting the stainless steel anodic dissolution. SEM experiments performed after immersion experiments at corrosion potential were in good agreement with the electrochemical results

  9. Effects of L-cysteine on lead acetate induced neurotoxicity in albino mice.

    Science.gov (United States)

    Mahmoud, Y I; Sayed, S S

    2016-07-01

    Lead is a toxic heavy metal that adversely affects nervous tissues; it often occurs as an environmental pollutant. We investigated histological changes in the cerebral cortex, hippocampus and cerebellum of adult albino mice following exposure to lead acetate. We also studied the possible ameliorative effect of the chelating agent, L-cysteine, on lead-induced neurotoxicity. We divided albino mice into six groups: 1) vehicle-only control, 2) L-cysteine control, 3 and 4) treated for 7 days with 20 and 40 mg/kg lead acetate, respectively, and 5 and 6) treated for 7 days with 20 and 40 mg/kg lead acetate, respectively, followed by 50 mg/kg L-cysteine for 7 days. Lead acetate administration caused disorganization of cell layers, neuronal loss and degeneration, and neuropil vacuolization. Brain sections from lead-intoxicated mice treated with L-cysteine showed fewer pathological changes; the neuropil showed less vacuolization and the neurons appeared less damaged. L-cysteine at the dose we used only marginally alleviated lead-induced toxicity.

  10. CMD: A Database to Store the Bonding States of Cysteine Motifs with Secondary Structures

    Directory of Open Access Journals (Sweden)

    Hamed Bostan

    2012-01-01

    Full Text Available Computational approaches to the disulphide bonding state and its connectivity pattern prediction are based on various descriptors. One descriptor is the amino acid sequence motifs flanking the cysteine residue motifs. Despite the existence of disulphide bonding information in many databases and applications, there is no complete reference and motif query available at the moment. Cysteine motif database (CMD is the first online resource that stores all cysteine residues, their flanking motifs with their secondary structure, and propensity values assignment derived from the laboratory data. We extracted more than 3 million cysteine motifs from PDB and UniProt data, annotated with secondary structure assignment, propensity value assignment, and frequency of occurrence and coefficiency of their bonding status. Removal of redundancies generated 15875 unique flanking motifs that are always bonded and 41577 unique patterns that are always nonbonded. Queries are based on the protein ID, FASTA sequence, sequence motif, and secondary structure individually or in batch format using the provided APIs that allow remote users to query our database via third party software and/or high throughput screening/querying. The CMD offers extensive information about the bonded, free cysteine residues, and their motifs that allows in-depth characterization of the sequence motif composition.

  11. Ga2O3 photocatalyzed on-line tagging of cysteine to facilitate peptide mass fingerprinting.

    Science.gov (United States)

    Qiao, Liang; Su, Fangzheng; Bi, Hongyan; Girault, Hubert H; Liu, Baohong

    2011-09-01

    β-Ga(2)O(3) is a wide-band-gap semiconductor having strong oxidation ability under light irradiation. Herein, the steel target plates modified with β-Ga(2)O(3) nanoparticles have been developed to carry out in-source photo-catalytic oxidative reactions for online peptide tagging during laser desorption/ionization mass spectrometry (LDI-MS) analysis. Under UV laser irradiation, β-Ga(2)O(3) can catalyze the photo-oxidation of 2-methoxyhydroquinone added to a sample mixture to 2-methoxy benzoquinone that can further react with the thiol groups of cysteine residues by Michael addition reaction. The tagging process leads to appearance of pairs of peaks with an m/z shift of 138.1Th. This online labelling strategy is demonstrated to be sensitive and efficient with a detection-limit at femtomole level. Using the strategy, the information on cysteine content in peptides can be obtained together with peptide mass, therefore constraining the database searching for an advanced identification of cysteine-containing proteins from protein mixtures. The current peptide online tagging method can be important for specific analysis of cysteine-containing proteins especially the low-abundant ones that cannot be completely isolated from other high-abundant non-cysteine-proteins. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Cysteine Cathepsins as Regulators of the Cytotoxicity of NK and T Cells

    Science.gov (United States)

    Perišić Nanut, Milica; Sabotič, Jerica; Jewett, Anahid; Kos, Janko

    2014-01-01

    Cysteine cathepsins are lysosomal peptidases involved at different levels in the processes of the innate and adaptive immune responses. Some, such as cathepsins B, L, and H are expressed constitutively in most immune cells. In cells of innate immunity they play a role in cell adhesion and phagocytosis. Other cysteine cathepsins are expressed more specifically. Cathepsin X promotes dendritic cell maturation, adhesion of macrophages, and migration of T cells. Cathepsin S is implicated in major histocompatibility complex class II antigen presentation, whereas cathepsin C, expressed in cytotoxic T lymphocytes and natural killer (NK) cells, is involved in processing pro-granzymes into proteolytically active forms, which trigger cell death in their target cells. The activity of cysteine cathepsins is controlled by endogenous cystatins, cysteine protease inhibitors. Of these, cystatin F is the only cystatin that is localized in endosomal/lysosomal vesicles. After proteolytic removal of its N-terminal peptide, cystatin F becomes a potent inhibitor of cathepsin C with the potential to regulate pro-granzyme processing and cell cytotoxicity. This review is focused on the role of cysteine cathepsins and their inhibitors in the molecular mechanisms leading to the cytotoxic activity of T lymphocytes and NK cells in order to address new possibilities for regulation of their function in pathological processes. PMID:25520721

  13. De novo Transcriptome Assembly and Comparison of C3, C3-C4, and C4 Species of Tribe Salsoleae (Chenopodiaceae

    Directory of Open Access Journals (Sweden)

    Maximilian Lauterbach

    2017-11-01

    Full Text Available C4 photosynthesis is a carbon-concentrating mechanism that evolved independently more than 60 times in a wide range of angiosperm lineages. Among other alterations, the evolution of C4 from ancestral C3 photosynthesis requires changes in the expression of a vast number of genes. Differential gene expression analyses between closely related C3 and C4 species have significantly increased our understanding of C4 functioning and evolution. In Chenopodiaceae, a family that is rich in C4 origins and photosynthetic types, the anatomy, physiology and phylogeny of C4, C2, and C3 species of Salsoleae has been studied in great detail, which facilitated the choice of six samples of five representative species with different photosynthetic types for transcriptome comparisons. mRNA from assimilating organs of each species was sequenced in triplicates, and sequence reads were de novo assembled. These novel genetic resources were then analyzed to provide a better understanding of differential gene expression between C3, C2 and C4 species. All three analyzed C4 species belong to the NADP-ME type as most genes encoding core enzymes of this C4 cycle are highly expressed. The abundance of photorespiratory transcripts is decreased compared to the C3 and C2 species. Like in other C4 lineages of Caryophyllales, our results suggest that PEPC1 is the C4-specific isoform in Salsoleae. Two recently identified transporters from the PHT4 protein family may not only be related to the C4 syndrome, but also active in C2 photosynthesis in Salsoleae. In the two populations of the C2 species S. divaricata transcript abundance of several C4 genes are slightly increased, however, a C4 cycle is not detectable in the carbon isotope values. Most of the core enzymes of photorespiration are highly increased in the C2 species compared to both C3 and C4 species, confirming a successful establishment of the C2 photosynthetic pathway. Furthermore, a function of PEP-CK in C2 photosynthesis

  14. Foot-and-Mouth Disease (FMD) Virus 3C Protease Mutant L127P: Implications for FMD Vaccine Development.

    Science.gov (United States)

    Puckette, Michael; Clark, Benjamin A; Smith, Justin D; Turecek, Traci; Martel, Erica; Gabbert, Lindsay; Pisano, Melia; Hurtle, William; Pacheco, Juan M; Barrera, José; Neilan, John G; Rasmussen, Max

    2017-11-15

    The foot-and-mouth disease virus (FMDV) afflicts livestock in more than 80 countries, limiting food production and global trade. Production of foot-and-mouth disease (FMD) vaccines requires cytosolic expression of the FMDV 3C protease to cleave the P1 polyprotein into mature capsid proteins, but the FMDV 3C protease is toxic to host cells. To identify less-toxic isoforms of the FMDV 3C protease, we screened 3C mutants for increased transgene output in comparison to wild-type 3C using a Gaussia luciferase reporter system. The novel point mutation 3C(L127P) increased yields of recombinant FMDV subunit proteins in mammalian and bacterial cells expressing P1-3C transgenes and retained the ability to process P1 polyproteins from multiple FMDV serotypes. The 3C(L127P) mutant produced crystalline arrays of FMDV-like particles in mammalian and bacterial cells, potentially providing a practical method of rapid, inexpensive FMD vaccine production in bacteria. IMPORTANCE The mutant FMDV 3C protease L127P significantly increased yields of recombinant FMDV subunit antigens and produced virus-like particles in mammalian and bacterial cells. The L127P mutation represents a novel advancement for economical FMD vaccine production. Copyright © 2017 Puckette et al.

  15. Development of α - Al_2O_3:C films nanoparticulate for application in digital radiology

    International Nuclear Information System (INIS)

    Silva, Edna C.; Fontainha, Crissia C.; Ferraz, Wilmar B.; Faria, Luiz O.

    2011-01-01

    Phosphorescent ceramics are widely used in Ionizing radiation sensors. In nuclear applications, alpha-alumina doped with carbon (α-Al_2O_3: C) is most commonly used because of its excellent properties photoluminescent (OSL) and thermoluminescent (TL) in ionizing radiation detections. Another application of OSL and TL materials is the use in digital radiography. Recently, Computerized Radiography (CR) equipment, which use OSL materials, have been replacing the old X-ray devices. In this work we investigated the thermoluminescence of α-Al_2O_3 doped with different percentages of carbon, sintered in reducing atmospheres, in temperatures from 1300 to 1750 ° C. The results indicate that micro alumina doped with 0.5% of carbon and nano-alumina doped with 2% of carbon present TL signal of the order of 30 to 100 times the signal of the TLD-100, the most widely used TL dosimeter in the world. The results indicate that α-Al_2O_3: C nano-particulate has great potential for application in digital thermoluminescent radiography, because of its high TL response to radiation Ionization and the possibility of forming TL digital images with resolution increased by about 1000 times, depending on the size of the nanoparticles

  16. 3C-SiC microdisk mechanical resonators with multimode resonances at radio frequencies

    Science.gov (United States)

    Lee, Jaesung; Zamani, Hamidrera; Rajgopal, Srihari; Zorman, Christian A.; X-L Feng, Philip

    2017-07-01

    We report on the design, modeling, fabrication and measurement of single-crystal 3C-silicon carbide (SiC) microdisk mechanical resonators with multimode resonances operating at radio frequencies (RF). These microdisk resonators (center-clamped on a vertical stem pedestal) offer multiple flexural-mode resonances with frequencies dependent on both disk and anchor dimensions. The resonators are made using a novel fabrication method comprised of focused ion beam nanomachining and hydroflouic : nitric : acetic (HNA) acid etching. Resonance peaks (in the frequency spectrum) are detected through laser-interferometry measurements. Resonators with different dimensions are tested, and multimode resonances, mode splitting, energy dissipation (in the form of quality factor measurement) are investigated. Further, we demonstrate a feedback oscillator based on a passive 3C-SiC resonator. This investigation provides important guidelines for microdisk resonator development, ranging from an analytical prediction of frequency scaling law to fabrication, suggesting RF microdisk resonators can be good candidates for future sensing applications in harsh environments.

  17. Mechanically activated synthesis of nanocrystalline ternary carbide Fe{sub 3}Mo{sub 3}C

    Energy Technology Data Exchange (ETDEWEB)

    Zakeri, M. [Materials Science Department, Islamic Azad University (Saveh branch), Saveh (Iran, Islamic Republic of)], E-mail: M_zakeri@iau-saveh.ac.ir; Rahimipour, M.R. [Ceramic Department, Materials and Energy Research Center, Tehran (Iran, Islamic Republic of); Khanmohammadian, A. [Materials Science Department, Islamic Azad University (Saveh branch), Saveh (Iran, Islamic Republic of)

    2008-09-25

    In this investigation, Fe{sub 3}Mo{sub 3}C ternary carbide was synthesized from the elemental powders of 3Mo/3Fe/C by mechanical milling and subsequent heat treatment. Structural and morphological evolutions of powders were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results showed that no phase transformation occurs during milling. A nanostructure Mo (Fe) solid solution obtained after 30 h of milling. With increasing milling time to 70 h no change takes place except grain size reduction to 9 nm and strain enhancement to 0.86%. Milled powders have spheroid shape and very narrow size distribution about 2 {mu}m at the end of milling. Fe{sub 3}Mo{sub 3}C was synthesized during annealing of 70 h milled sample at 700 deg. C. Undesired phases of MoOC and Fe{sub 2}C form at 1100 deg. C. No transformation takes place during annealing of 10 h milled sample at 700 deg. C. Mean grain size and strain get to 69 nm and 0.23% respectively with annealing of 70 h milled sample at 1100 deg. C.

  18. Mechanically activated synthesis of nanocrystalline ternary carbide Fe3Mo3C

    International Nuclear Information System (INIS)

    Zakeri, M.; Rahimipour, M.R.; Khanmohammadian, A.

    2008-01-01

    In this investigation, Fe 3 Mo 3 C ternary carbide was synthesized from the elemental powders of 3Mo/3Fe/C by mechanical milling and subsequent heat treatment. Structural and morphological evolutions of powders were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results showed that no phase transformation occurs during milling. A nanostructure Mo (Fe) solid solution obtained after 30 h of milling. With increasing milling time to 70 h no change takes place except grain size reduction to 9 nm and strain enhancement to 0.86%. Milled powders have spheroid shape and very narrow size distribution about 2 μm at the end of milling. Fe 3 Mo 3 C was synthesized during annealing of 70 h milled sample at 700 deg. C. Undesired phases of MoOC and Fe 2 C form at 1100 deg. C. No transformation takes place during annealing of 10 h milled sample at 700 deg. C. Mean grain size and strain get to 69 nm and 0.23% respectively with annealing of 70 h milled sample at 1100 deg. C

  19. Semantic validation of standard-based electronic health record documents with W3C XML schema.

    Science.gov (United States)

    Rinner, C; Janzek-Hawlat, S; Sibinovic, S; Duftschmid, G

    2010-01-01

    The goal of this article is to examine whether W3C XML Schema provides a practicable solution for the semantic validation of standard-based electronic health record (EHR) documents. With semantic validation we mean that the EHR documents are checked for conformance with the underlying archetypes and reference model. We describe an approach that allows XML Schemas to be derived from archetypes based on a specific naming convention. The archetype constraints are augmented with additional components of the reference model within the XML Schema representation. A copy of the EHR document that is transformed according to the before-mentioned naming convention is used for the actual validation against the XML Schema. We tested our approach by semantically validating EHR documents conformant to three different ISO/EN 13606 archetypes respective to three sections of the CDA implementation guide "Continuity of Care Document (CCD)" and an implementation guide for diabetes therapy data. We further developed a tool to automate the different steps of our semantic validation approach. For two particular kinds of archetype prescriptions, individual transformations are required for the corresponding EHR documents. Otherwise, a fully generic validation is possible. In general, we consider W3C XML Schema as a practicable solution for the semantic validation of standard-based EHR documents.

  20. RAiSE III: 3C radio AGN energetics and composition

    Science.gov (United States)

    Turner, Ross J.; Shabala, Stanislav S.; Krause, Martin G. H.

    2018-03-01

    Kinetic jet power estimates based exclusively on observed monochromatic radio luminosities are highly uncertain due to confounding variables and a lack of knowledge about some aspects of the physics of active galactic nuclei (AGNs). We propose a new methodology to calculate the jet powers of the largest, most powerful radio sources based on combinations of their size, lobe luminosity, and shape of their radio spectrum; this approach avoids the uncertainties encountered by previous relationships. The outputs of our model are calibrated using hydrodynamical simulations and tested against independent X-ray inverse-Compton measurements. The jet powers and lobe magnetic field strengths of radio sources are found to be recovered using solely the lobe luminosity and spectral curvature, enabling the intrinsic properties of unresolved high-redshift sources to be inferred. By contrast, the radio source ages cannot be estimated without knowledge of the lobe volumes. The monochromatic lobe luminosity alone is incapable of accurately estimating the jet power or source age without knowledge of the lobe magnetic field strength and size, respectively. We find that, on average, the lobes of the Third Cambridge Catalogue of Radio Sources (3C) have magnetic field strengths approximately a factor three lower than the equipartition value, inconsistent with equal energy in the particles and the fields at the 5σ level. The particle content of 3C radio lobes is discussed in the context of complementary observations; we do not find evidence favouring an energetically dominant proton population.

  1. The strength of electron electron correlation in Cs3C60

    Science.gov (United States)

    Baldassarre, L.; Perucchi, A.; Mitrano, M.; Nicoletti, D.; Marini, C.; Pontiroli, D.; Mazzani, M.; Aramini, M.; Riccó, M.; Giovannetti, G.; Capone, M.; Lupi, S.

    2015-10-01

    Cs3C60 is an antiferromagnetic insulator that under pressure (P) becomes metallic and superconducting below Tc = 38 K. The superconducting dome present in the T - P phase diagram close to a magnetic state reminds what found in superconducting cuprates and pnictides, strongly suggesting that superconductivity is not of the conventional Bardeen-Cooper-Schrieffer (BCS) type We investigate the insulator to metal transition induced by pressure in Cs3C60 by means of infrared spectroscopy supplemented by Dynamical Mean-Field Theory calculations. The insulating compound is driven towards a metallic-like behaviour, while strong correlations survive in the investigated pressure range. The metallization process is accompanied by an enhancement of the Jahn-Teller effect. This shows that electronic correlations are crucial in determining the insulating behaviour at ambient pressure and the bad metallic nature for increasing pressure. On the other hand, the relevance of the Jahn-Teller coupling in the metallic state confirms that phonon coupling survives in the presence of strong correlations.

  2. Confining hot spots in 3C 196 - implications for QSO-companion galaxies

    International Nuclear Information System (INIS)

    Brown, R.L.; Broderick, J.J.; Mitchell, K.J.; Virginia Polytechnic Institute and State Univ., Blacksburg; NASA, Goddard Space Flight Center, Greenbelt, MD)

    1986-01-01

    VLBI observations of the extremely compact hot spot in the northern radio lobe of the QSO 3C 196 reveal the angular size of its smallest substructure to be 0.065 arcsec x 0.045 arcsec or about 300 pc at the redshift distance. The morphology of the hot spot and its orientation relative to the more diffuse radio emission suggest that it is formed by an oblique interaction between the nuclear QSO jet and circum-QSO cloud. The inferred density in this cloud, together with its apparent size, imply that the cloud contains a galactic mass, greater than a billion solar masses of gas. The effect of the jet will be to hasten gravitational collapse of the cloud. If many QSOs such as 3C 196 are formed or found in gas-rich environments, the QSO radio phase may commonly stimulate the metamorphosis of circum-QSO gas to QSO-companion galaxies or it may play a significant part in catalyzing star formation in existing companions. 30 references

  3. The impacts of source structure on geodetic parameters demonstrated by the radio source 3C371

    Science.gov (United States)

    Xu, Ming H.; Heinkelmann, Robert; Anderson, James M.; Mora-Diaz, Julian; Karbon, Maria; Schuh, Harald; Wang, Guang L.

    2017-07-01

    Closure quantities measured by very-long-baseline interferometry (VLBI) observations are independent of instrumental and propagation instabilities and antenna gain factors, but are sensitive to source structure. A new method is proposed to calculate a structure index based on the median values of closure quantities rather than the brightness distribution of a source. The results are comparable to structure indices based on imaging observations at other epochs and demonstrate the flexibility of deriving structure indices from exactly the same observations as used for geodetic analysis and without imaging analysis. A three-component model for the structure of source 3C371 is developed by model-fitting closure phases. It provides a real case of tracing how the structure effect identified by closure phases in the same observations as the delay observables affects the geodetic analysis, and investigating which geodetic parameters are corrupted to what extent by the structure effect. Using the resulting structure correction based on the three-component model of source 3C371, two solutions, with and without correcting the structure effect, are made. With corrections, the overall rms of this source is reduced by 1 ps, and the impacts of the structure effect introduced by this single source are up to 1.4 mm on station positions and up to 4.4 microarcseconds on Earth orientation parameters. This study is considered as a starting point for handling the source structure effect on geodetic VLBI from geodetic sessions themselves.

  4. Potent Inhibition of Feline Coronaviruses with Peptidyl Compounds Targeting Coronavirus 3C-like Protease

    Science.gov (United States)

    Kim, Yunjeong; Mandadapu, Sivakoteswara Rao; Groutas, William C.; Chang, Kyeong-Ok

    2012-01-01

    Feline coronavirus infection is common among domestic and exotic felid species and usually associated with mild or asymptomatic enteritis; however, feline infectious peritonitis (FIP) is a fatal disease of cats that is caused by systemic infection with a feline infectious peritonitis virus (FIPV), a variant of feline enteric coronavirus (FECV). Currently, there is no specific treatment approved for FIP despite the importance of FIP as the leading infectious cause of death in young cats. During the replication process, coronavirus produces viral polyproteins that are processed into mature proteins by viral proteases, the main protease (3C-like [3CL] protease) and the papain-like protease. Since the cleavages of viral polyproteins are an essential step for virus replication, blockage of viral protease is an attractive target for therapeutic intervention. Previously, we reported the generation of broad-spectrum peptidyl inhibitors against viruses that possess a 3C or 3CL protease. In this study, we further evaluated the antiviral effects of the peptidyl inhibitors against feline coronaviruses, and investigated the interaction between our protease inhibitor and a cathepsin B inhibitor, an entry blocker, against feline coronaviruses in cell culture. Herein we report that our compounds behave as reversible, competitive inhibitors of 3CL protease, potently inhibited the replication of feline coronaviruses (EC50 in a nanomolar range) and, furthermore, the combination of cathepsin B and 3CL protease inhibitors led to a strong synergistic interaction against feline coronaviruses in cell culture systems. PMID:23219425

  5. Theoretical studies on band structure and optical properties of 3C-SiC by FPLAPW

    International Nuclear Information System (INIS)

    Xu, P.; Xie, C.; Xu, F.; Pan, H.

    2004-01-01

    Full text: SiC has attracted more interests because of its great technological importance in microelectronic and photoelectronic devices. We have studied the band structure and optical properties of 3C-SiC by using a Full Potential Linearized Augmented Plane Waves (FPLAPW) method. The partial density of states (DOS) of Si and C atoms as well as the band structure of 3C-SiC are presented. The calculated band gap is 1.30eV, which is much less than the experimental value. It is attributed to a deficiency of the local density theory. The imaginary part of the dielectric function has been obtained directly from the band structure calculation. With the band gap correction, the real part of the dielectric function has been derived from the imaginary part by Kramers Kronig (K-K) dispersion relationship. The calculated results are in good agreement with the results measured by Petalas et al. by using ultraviolet spectroscopic ellipsometry in the photon energy range of 5eV-10eV. The band-to-band transition can be identified from the critical points exhibited in the calculated dielectric function, which is consistent with the experimental results of Petalas et al. The refractive index, extinction coefficient and reflectivity have also been calculated from obtained dielectric function, which are in agreement with the experimental results of Logothetidis and Lambrecht

  6. Flow patterns in radio hot spots - A study of 3C 33 north

    International Nuclear Information System (INIS)

    Rudnick, L.; Anderson, M.

    1990-01-01

    High-resolution (0.36 arcsec, 0.41 kpc) observations of the northern hot spot of the radio galaxy 3C 33 show a symmetric mushroom cap structure, with a centrally placed H-shaped feature and two opposed small bright regions. Two models for the flow patterns in this hot spot are explored. The first is the 'splash' picture, in which the brightest compact feature is identified as the primary hot spot and the rest of the structures result from the jet's expanded, deflected flow. Although most observed features are consistent with this picture, they do not help discriminate against alternative models. The second, axisymmetric, picture compares the observations with numerical simulations of jets with helical magnetic fields. Good agreement was found with the geometrical and magnetic field properties, although significant questions remain about the synchrotron emissivity characteristics. The differences between the northern and southern hot spots of 3C 33 are briefly discussed, and it is suggested that there are no good explanations for these differences in the context of current models. 28 refs

  7. Factors of Nonlinear-ultrasonic Detection and Its Application to HR3C Fireside Corrosion

    Directory of Open Access Journals (Sweden)

    QIN Peng

    2016-11-01

    Full Text Available Based on the discussion of the factors influencing the nonlinear ultrasonic testing, the feasibility of nondestructive evaluation of HR3C fireside corrosion was investigated using nonlinear ultrasonic testing. The results show that the number of pulse string is no more than 2df/c and the installation of Hanning window is helpful to reduce the disturbance of the system, in addition, the rough surface of the sample has a significant impact on the nonlinear parameter β. The nonlinear coefficient demonstrates a phased growth trend as corrosion time prolongs. At the initial stage of corrosion(within 50h,there are small increments within 20% in the nonlinear coefficient, however,the nonlinear coefficient β is increased obviously with the duration time to 150h. Compared with un-corroded sample, the amplification in the sample corroded for 200h reaches to 260%. The monotonous varieties in nonlinear coefficient are consistent with the aggravation of corrosion damage,hence,it is feasible to nondestructively evaluate HR3C fireside corrosion by means of ultrasonic nonlinear testing.

  8. Guidelines for Synthesis and Processing of 2D Titanium Carbide (Ti3C2Tx MXene)

    KAUST Repository

    Alhabeb, Mohamed

    2017-08-25

    Two-dimensional (2D) transition metal carbides, carbonitrides and nitrides (MXenes) were discovered in 2011. Since the original discovery, more than 20 different compositions have been synthesized by the selective etching of MAX phase and other precursors and many more theoretically predicted. They offer a variety of different properties, making the family promising candidates in a wide range of applications, such as energy storage, electromagnetic interference shielding, water purification, electrocatalysis and medicine. These solution-processable materials have the potential to be highly scalable, deposited by spin, spray or dip coating, painted or printed, or fabricated in a variety of ways. Due to this promise, the amount of research on MXenes has been increasing, and methods of synthesis and processing are expanding quickly. The fast evolution of the material can also be noticed in the wide range of synthesis and processing protocols that determine the yield of delamination, as well as the quality of the 2D flakes produced. Here we describe the experimental methods and best practices we use to synthesize the most studied MXene, titanium carbide (Ti3C2Tx), using different etchants and delamination methods. We also explain effects of synthesis parameters on the size and quality of Ti3C2Tx and suggest the optimal processes for the desired application.

  9. Temperature dependence of the Al2O3:C response in medical luminescence dosimetry

    International Nuclear Information System (INIS)

    Edmund, Jens M.; Andersen, Claus E.

    2007-01-01

    Over the last years, attention has been given to applications of Al 2 O 3 :C in space and medical dosimetry. One such application is in vivo dose verification in radiotherapy of cancer patients and here we investigate the temperature effects on the radioluminescence (RL) and optically stimulated luminescence (OSL) signals in the room-to-body temperature region. We found that the OSL response changes with both irradiation and stimulation temperatures as well as the OSL integration time. We conclude that temperature effects on the OSL response can be removed by integration if the irradiation temperature is not varied. The RL response only depends on the irradiation temperature. We recommend that calibration should be carried out at the same irradiation temperature at which the measurement is performed (i.e. at body temperature for in vivo measurements). The overall change in the integrated OSL and RL signals with irradiation and stimulation temperature covers an interval from -0.2% to 0.6% per deg. C. This indicates the correction factor one must take into account when performing luminescence dosimetry at different temperatures. The same effects were observed regardless of crystal type, test doses and stimulation and detection wavelengths. The reported temperature dependence seems to be a general property of Al 2 O 3 :C

  10. Development of Cr3C2-25(Ni20Cr) nanostructured coatings

    International Nuclear Information System (INIS)

    Cunha, Cecilio Alvares da

    2012-01-01

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

  11. Anti-trypanosomal activity of non-peptidic nitrile-based cysteine protease inhibitors.

    Science.gov (United States)

    Burtoloso, Antonio C B; de Albuquerque, Sérgio; Furber, Mark; Gomes, Juliana C; Gonçalez, Cristiana; Kenny, Peter W; Leitão, Andrei; Montanari, Carlos A; Quilles, José Carlos; Ribeiro, Jean F R; Rocha, Josmar R

    2017-02-01

    The cysteine protease cruzipain is considered to be a validated target for therapeutic intervention in the treatment of Chagas disease. Anti-trypanosomal activity against the CL Brener strain of T. cruzi was observed in the 0.1 μM to 1 μM range for three nitrile-based cysteine protease inhibitors based on two scaffolds known to be associated with cathepsin K inhibition. The two compounds showing the greatest potency against the trypanosome were characterized by EC50 values (0.12 μM and 0.25 μM) that were an order of magnitude lower than the corresponding Ki values measured against cruzain, a recombinant form of cruzipain, in an enzyme inhibition assay. This implies that the anti-trypanosomal activity of these two compounds may not be explained only by the inhibition of the cruzain enzyme, thereby triggering a putative polypharmacological profile towards cysteine proteases.

  12. Optical Absorption and Electric Resistivity of an l-Cysteine Film

    Science.gov (United States)

    Kamada, Masao; Hideshima, Takuya; Azuma, Junpei; Yamamoto, Isamu; Imamura, Masaki; Takahashi, Kazutoshi

    2016-12-01

    The optical and electric properties of an l-cysteine film have been investigated to understand its applicability to bioelectronics. The fundamental absorption is the allowed transition having the threshold at 5.8 eV and the absorption is due to the charge-transfer type transition from sulfur-3sp to oxygen-2p and/or carbon-2p states, while absorptions more than 9 eV can be explained with intra-atomic transitions in the functional groups. The electric resistivity is 2.0 × 104 Ω m at room temperature and increases as the sample temperature decreases. The results indicate that the l-cysteine film is a p-type semiconductor showing the hole conduction caused by the sulfur-3sp occupied states and unknown impurity or defect states as acceptors. The electron affinity of the l-cysteine film is derived as ≦-0.3 eV.

  13. Influence of cysteine and selenodicysteine on the uptake of zinc by Chlorella vulgaris Beijerinck

    International Nuclear Information System (INIS)

    Czauderna, M.; Samochocka, K.

    1982-01-01

    The uptake of zinc labelled with radioactive 65 Zn in the presence of cysteine and selenodicysteine by Chlorella vulgaris was examined. The concentration of zinc ions in the medium was 20 mg per 1. The uptake yield was found to be enhanced by selenodicysteine. At concentration of 10 - 7 -10 - 6 M the growth rate of Chlorella vulgaris was accelerated by the latter, provided that the specific activity of 65 Zn was 3.7 MBq/1. At this specific zinc activity cysteine increased the uptake yield during the initial 50 h of the incubation process. At specific 65 Zn-activity of 55.5 MBq/1 selenodicysteine and cysteine only slightly influenced the zinc uptake by Chlorella vulgaris. No increment in the biomass was observed at this specific zinc radioactivity. (author)

  14. L-Cysteine Capped CdSe Quantum Dots Synthesized by Photochemical Route.

    Science.gov (United States)

    Singh, Avinash; Kunwar, Amit; Rath, M C

    2018-05-01

    L-cysteine capped CdSe quantum dots were synthesized via photochemical route in aqueous solution under UV photo-irradiation. The as grown CdSe quantum dots exhibit broad fluorescence at room temperature. The CdSe quantum dots were found to be formed only through the reactions of the precursors, i.e., Cd(NH3)2+4 and SeSO2-3 with the photochemically generated 1-hydroxy-2-propyl radicals, (CH3)2COH radicals, which are formed through the process of H atom abstraction by the photoexcited acetone from 2-propanol. L-Cysteine was found to act as a suitable capping agent for the CdSe quantum dots and increases their biocompatability. Cytotoxicty effects of these quantum dots were evaluated in Chinese Hamster Ovary (CHO) epithelial cells, indicated a significant lower level for the L-cysteine capped CdSe quantum dots as compare to the bare ones.

  15. Reduction of mercury from mackerel fillet using combined solution of cysteine, EDTA, and sodium chloride.

    Science.gov (United States)

    Hajeb, P; Jinap, S

    2012-06-13

    An acidic solution containing mercury chelating agents to eliminate mercury in raw fish (mackerel) fillet was developed. The solution contained hydrochloric acid, sodium hydroxide, cysteine, EDTA, and NaCl. The optimum conditions for mercury reduction were achieved using response surface methodology (RSM) at cysteine concentration of 1.25%, EDTA of 275 mg/L, NaCl of 0.5%, pH of 3.75, and exposure time of 18 min. The optimized conditions produced a solution which can remove up to 91% mercury from raw fish fillet. Cysteine and EDTA were identified as potential chelating agents with the greatest potential for use. The solution can be employed in fish industries to reduce mercury in highly contaminated fish.

  16. Do cysteine residues regulate transient receptor potential canonical type 6 (TRPC6) channel protein expression?

    DEFF Research Database (Denmark)

    Thilo, Florian; Liu, Ying; Krueger, Katharina

    2012-01-01

    The regulation of calcium influx through transient receptor potential canonical type 6 channel is mandatory for the activity of human monocytes. We submit the first evidence that cysteine residues of homocysteine or acetylcysteine affect TRPC6 expression in human monocytes. We observed that patie......The regulation of calcium influx through transient receptor potential canonical type 6 channel is mandatory for the activity of human monocytes. We submit the first evidence that cysteine residues of homocysteine or acetylcysteine affect TRPC6 expression in human monocytes. We observed...... that patients with chronic renal failure had significantly elevated homocysteine levels and TRPC6 mRNA expression levels in monocytes compared to control subjects. We further observed that administration of homocysteine or acetylcysteine significantly increased TRPC6 channel protein expression compared...... to control conditions. We therefore hypothesize that cysteine residues increase TRPC6 channel protein expression in humans....

  17. Biological roles of cysteine proteinases in the pathogenesis of Trichomonas vaginalis

    Science.gov (United States)

    Hernández, Hilda M.; Marcet, Ricardo; Sarracent, Jorge

    2014-01-01

    Human trichomonosis, infection with Trichomonas vaginalis, is the most common non-viral sexually transmitted disease in the world. The host-parasite interaction and pathophysiological processes of trichomonosis remain incompletely understood. This review focuses on the advancements reached in the area of the pathogenesis of T. vaginalis, especially in the role of the cysteine proteinases. It highlights various approaches made in this field and lists a group of trichomonad cysteine proteinases involved in diverse processes such as invasion of the mucous layer, cytoadherence, cytotoxicity, cytoskeleton disruption of red blood cells, hemolysis, and evasion of the host immune response. A better understanding of the biological roles of cysteine proteinases in the pathogenesis of this parasite could be used in the identification of new chemotherapeutic targets. An additional advantage could be the development of a vaccine in order to reduce transmission of T. vaginalis. PMID:25348828

  18. Thermo-Kinetic Investigation of Comparative Ligand Effect on Cysteine Iron Redox Reaction

    Directory of Open Access Journals (Sweden)

    Masood Ahmad Rizvi

    2015-03-01

    Full Text Available Transition metal ions in their free state bring unwanted biological oxidations generating oxidative stress. The ligand modulated redox potential can be indispensable in prevention of such oxidative stress by blocking the redundant bio-redox reactions. In this study we investigated the comparative ligand effect on the thermo-kinetic aspects of biologically important cysteine iron (III redox reaction using spectrophotometric and potentiometric methods. The results were corroborated with the complexation effect on redox potential of iron(III-iron(II redox couple. The selected ligands were found to increase the rate of cysteine iron (III redox reaction in proportion to their stability of iron (II complex (EDTA < terpy < bipy < phen. A kinetic profile and the catalytic role of copper (II ions by means of redox shuttle mechanism for the cysteine iron (III redox reaction in presence of 1,10-phenanthroline (phen ligand is also reported.

  19. S-Substituted cysteine derivatives and thiosulfinate formation in Petiveria alliacea-part II.

    Science.gov (United States)

    Kubec, Roman; Kim, Seokwon; Musah, Rabi A

    2002-11-01

    Three cysteine derivatives, (R)-S-(2-hydroxyethyl)cysteine, together with (R(S)R(C))- and (S(S)R(C))-S-(2-hydroxyethyl)cysteine sulfoxides, have been isolated from the roots of Petiveria alliacea. Furthermore, three additional amino acids, S-methyl-, S-ethyl-, and S-propylcysteine derivatives, were detected. They were present only in trace amounts (<3 microg g(-1) fr. wt), precluding determination of their absolute configurations and oxidation states. In addition, four thiosulfinates, S-(2-hydroxyethyl) (2-hydroxyethane)-, S-(2-hydroxyethyl) phenylmethane-, S-benzyl (2-hydroxyethane)- and S-benzyl phenylmethanethiosulfinates, have been found in a homogenate of the roots. The formation pathways of various benzyl/phenyl-containing compounds previously found in the plant were also discussed.

  20. The proteins of Fusobacterium spp. involved in hydrogen sulfide production from L-cysteine.

    Science.gov (United States)

    Basic, Amina; Blomqvist, Madeleine; Dahlén, Gunnar; Svensäter, Gunnel

    2017-03-14

    Hydrogen sulfide (H 2 S) is a toxic foul-smelling gas produced by subgingival biofilms in patients with periodontal disease and is suggested to be part of the pathogenesis of the disease. We studied the H 2 S-producing protein expression of bacterial strains associated with periodontal disease. Further, we examined the effect of a cysteine-rich growth environment on the synthesis of intracellular enzymes in F. nucleatum polymorphum ATCC 10953. The proteins were subjected to one-dimensional (1DE) and two-dimensional (2DE) gel electrophoresis An in-gel activity assay was used to detect the H 2 S-producing enzymes; Sulfide from H 2 S, produced by the enzymes in the gel, reacted with bismuth forming bismuth sulfide, illustrated as brown bands (1D) or spots (2D) in the gel. The discovered proteins were identified with liquid chromatography - tandem mass spectrometry (LC-MS/MS). Cysteine synthase and proteins involved in the production of the coenzyme pyridoxal 5'phosphate (that catalyzes the production of H 2 S) were frequently found among the discovered enzymes. Interestingly, a higher expression of H 2 S-producing enzymes was detected from bacteria incubated without cysteine prior to the experiment. Numerous enzymes, identified as cysteine synthase, were involved in the production of H 2 S from cysteine and the expression varied among Fusobacterium spp. and strains. No enzymes were detected with the in-gel activity assay among the other periodontitis-associated bacteria tested. The expression of the H 2 S-producing enzymes was dependent on environmental conditions such as cysteine concentration and pH but less dependent on the presence of serum and hemin.

  1. An Assay Study of Molecular Recognition of Amino Acids in Water: Covalent Imprinting of Cysteine

    DEFF Research Database (Denmark)

    Burri, Harsha Vardhan Reddy; Yu, Donghong

    2015-01-01

    A novel synthetic N-(9-fluorenyl methoxy carbonyl)-L-Cysteine (Fmoc-Cys(SH)-OH) receptor was pre- pared by co-polymerizing (9-fluorenyl methoxy carbonyl)-S-(1-propene-2-thiol)-L-Cysteine (Fmoc-Cys(SCH2CHCH2)-OH) and a non-imprinted polymer prepared from 1-propene-1-thiol photo-chemically 15 h...... at room temperature and additional 3 h thermally at 80℃. Subsequently, disulfides were reduced with lithium aluminum hydride (LiAlH4) from imprinted polymers. The imprinted polymers selectively recognized Fmoc-Cys(SH)-OH with high binding constants in aqueous and protic solvents by thiol...

  2. A simple synthesis of L-[35S]cysteine sulfinic acid

    International Nuclear Information System (INIS)

    Spears, R.M.; Martin, D.L.

    1981-01-01

    The synthesis of L-[ 35 S]cysteine sulfinic acid (L-2-amino-3-[ 35 S]sulfino-propanoic acid) in 65% yield from S-[ 35 S]cystine is described. The procedure was designed for use with milligram quantities of starting material and requires no purification of intermediates. L-[ 35 S]Cystine was converted first to its thiosulfonate. Subsequent reaction of the thiosulfonate with ammonium hydroxide generated L-[ 35 S]cysteine sulfinic acid and L-[ 35 S]cystine as the major products. The L-[ 35 S]cystine was recovered and reprocessed thereby increasing the yield. (author)

  3. Parameters optimization defined by statistical analysis for cysteine-dextran radiolabeling with technetium tricarbonyl core.

    Science.gov (United States)

    Núñez, Eutimio Gustavo Fernández; Faintuch, Bluma Linkowski; Teodoro, Rodrigo; Wiecek, Danielle Pereira; da Silva, Natanael Gomes; Papadopoulos, Minas; Pelecanou, Maria; Pirmettis, Ioannis; de Oliveira Filho, Renato Santos; Duatti, Adriano; Pasqualini, Roberto

    2011-04-01

    The objective of this study was the development of a statistical approach for radiolabeling optimization of cysteine-dextran conjugates with Tc-99m tricarbonyl core. This strategy has been applied to the labeling of 2-propylene-S-cysteine-dextran in the attempt to prepare a new class of tracers for sentinel lymph node detection, and can be extended to other radiopharmaceuticals for different targets. The statistical routine was based on three-level factorial design. Best labeling conditions were achieved. The specific activity reached was 5 MBq/μg. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  4. Parameters optimization defined by statistical analysis for cysteine-dextran radiolabeling with technetium tricarbonyl core

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Nunez, Eutimio Gustavo, E-mail: eutimiocu@yahoo.co [Radiopharmacy Center, Institute of Energetic and Nuclear Research, Sao Paulo, SP 05508-000 (Brazil); Linkowski Faintuch, Bluma; Teodoro, Rodrigo; Pereira Wiecek, Danielle; Gomes da Silva, Natanael [Radiopharmacy Center, Institute of Energetic and Nuclear Research, Sao Paulo, SP 05508-000 (Brazil); Papadopoulos, Minas [Institute of Radioisotopes, Radiodiagnostic Products, National Center for Scientific Research ' Demokritos' , Athens (Greece); Pelecanou, Maria [Institute of Biology, National Center for Scientific Research ' Demokritos' , Athens (Greece); Pirmettis, Ioannis [Institute of Radioisotopes, Radiodiagnostic Products, National Center for Scientific Research ' Demokritos' , Athens (Greece); Santos Oliveira Filho, Renato de [Faculty of Medicine, Federal University of Sao Paulo, SP (Brazil); Duatti, Adriano [Department of Radiological Sciences, University of Ferrara, Ferrara (Italy); Pasqualini, Roberto [CIS Bio International, Gif sur Yvette (France)

    2011-04-15

    The objective of this study was the development of a statistical approach for radiolabeling optimization of cysteine-dextran conjugates with Tc-99m tricarbonyl core. This strategy has been applied to the labeling of 2-propylene-S-cysteine-dextran in the attempt to prepare a new class of tracers for sentinel lymph node detection, and can be extended to other radiopharmaceuticals for different targets. The statistical routine was based on three-level factorial design. Best labeling conditions were achieved. The specific activity reached was 5 MBq/{mu}g.

  5. Formation of Hg(II) Tetrathiolate Complexes with Cysteine at Neutral pH.

    Science.gov (United States)

    Warner, Thomas; Jalilehvand, Farideh

    2016-04-01

    Mercury(II) ions precipitate from aqueous cysteine (H 2 Cys) solutions containing H 2 Cys/Hg(II) mole ratio ≥ 2.0 as Hg( S -HCys) 2 . In absence of additional cysteine, the precipitate dissolves at pH ~12 with the [Hg( S,N -Cys) 2 ] 2- complex dominating. With excess cysteine (H 2 Cys/Hg(II) mole ratio ≥ 4.0), higher complexes form and the precipitate dissolves at lower pH values. Previously, we found that tetrathiolate [Hg( S -Cys) 4 ] 6- complexes form at pH = 11.0; in this work we extend the investigation to pH values of physiological interest. We examined two series of Hg(II)-cysteine solutions in which C Hg(II) varied between 8 - 9 mM and 80 - 100 mM, respectively, with H 2 Cys/Hg(II) mole ratios from 4 to ~20. The solutions were prepared in the pH range 7.1 - 8.8, at the pH at which the initial Hg( S -HCys) 2 precipitate dissolved. The variations in the Hg(II) speciation were followed by 199 Hg NMR, X-ray absorption and Raman spectroscopic techniques. Our results show that in the dilute solutions ( C Hg(II) = 8 - 9 mM), mixtures of di-, tri- (major) and tetrathiolate complexes exist at moderate cysteine excess ( C H2Cys ~ 0.16 M) at pH 7.1. In the more concentrated solutions ( C Hg(II) = 80 - 100 mM) with high cysteine excess ( C H2Cys > 0.9 M), tetrathiolate [Hg( S -cysteinate) 4 ] m -6 ( m = 0 - 4) complexes dominate in the pH range 7.3 - 7.8, with lower charge than for the [Hg( S -Cys) 4 ] 6- complex due to protonation of some ( m ) of the amino groups of the coordinated cysteine ligands. The results of this investigation could provide a key to the mechanism of biosorption and accumulation of Hg(II) ions in biological / environmental systems.

  6. Micronutrients, N-Acetyl Cysteine, Probiotics and Prebiotics, a Review of Effectiveness in Reducing HIV Progression

    Science.gov (United States)

    Hummelen, Ruben; Hemsworth, Jaimie; Reid, Gregor

    2010-01-01

    Low serum concentrations of micronutrients, intestinal abnormalities, and an inflammatory state have been associated with HIV progression. These may be ameliorated by micronutrients, N-acetyl cysteine, probiotics, and prebiotics. This review aims to integrate the evidence from clinical trials of these interventions on the progression of HIV. Vitamin B, C, E, and folic acid have been shown to delay the progression of HIV. Supplementation with selenium, N-acetyl cysteine, probiotics, and prebiotics has considerable potential, but the evidence needs to be further substantiated. Vitamin A, iron, and zinc have been associated with adverse effects and caution is warranted for their use. PMID:22254046

  7. Labeling of human serum albumin with 105Rh-cysteine complexes

    International Nuclear Information System (INIS)

    Lo, J.M.; Pillai, M.R.A.; John, C.S.; Troutner, D.E.

    1990-01-01

    The conjugation of a complex formed by reacting RhCl 3 with cysteine to human serum albumin has been investigated. Approximately 50% of the rhodium (labelled with 105 Rh) was converted to the complex. Conjugation of the complex to HSA via the ECDI method resulted in yields of ∼ 40% of the total rhodium or ∼ 80% of the Rh-cysteine complex. No conjugation was observed in the absence of the ECDI. At approximately equal molar concentrations of rhodium and HSA, an average of ∼ 0.4 rhodium atoms per HSA molecule was achieved. (author)

  8. Study of the irradiation defects in 3C-SiC

    International Nuclear Information System (INIS)

    Lefevre, J.

    2007-01-01

    This work deals with the study of the irradiation defects in the cubic polytype 3C of the n type silicon carbide. Low temperature photoluminescence and electron spin resonance techniques have been used. In situ photoluminescence measurements after irradiation at 10 K by electrons have shown that the nature of the defects induced is identical to those observed after irradiation at ambient temperature with electrons, protons or carbon ions. No regeneration of these defects has been revealed after in situ annealings until 300 K. The electrons Van de Graff accelerator of the Irradiated Solid Laboratory has allowed to irradiate sample of 3C in a range of energies between 190 keV and 1 MeV. It has then been possible to estimate the appearance threshold of the irradiation defects but especially to be able to determine the displacement threshold energy of silicon in this SiC polytype. The found value of 25 eV is in good agreement with the first experimental result proposed by X. Kerbiriou with the use of the ESR. Annealings in the range of high temperatures have been carried out. The evolution of the irradiation defects has been followed in photoluminescence and in ESR. The results show that, in one part, the vacancy of the silicon negatively charged is essentially the only compensating defect in 3C-SiC of n type and that, in another part, the majority of the defects are annealed below 1200 C. Only the D1 defect remains after annealings until 1600 C. The D1 center is in fact a native defect in SiC; indeed, it has been identified alone in non irradiated samples. A systematic study of these last samples show the absence of D1 in samples strongly compensated. The compared results of photoluminescence and of positons annihilation are in good agreement for the possible attribution of D1 to the bi-vacancy V C -V Si . One of the most interesting result of this last work has been obtained using the ESR technique under excitation with a neodymium laser. The measurements, carried

  9. Effects of temperature and ionization density in medical luminescence dosimetry using Al2O3:C

    International Nuclear Information System (INIS)

    Morgenthaler Edmund, J.

    2007-11-01

    A new system containing small crystals of aluminum oxide doped with carbon (Al 2 O 3 :C) attached to optical fiber cables has recently been introduced. During irradiation, the system monitors the radioluminescence (RL)from the crystals and after irradiation, an optically stimulated luminescence (OSL) signal can be read out by stimulating the crystal with light. This thesis applies the initial part and the total area of the resulting OSL decay curve for dosimetry measurements and investigates the effects of temperature and proton energy, i.e. ionization density, on the RL and OSL signals from Al 2 O 3 :C. In the temperature study, it was found that the OSL signal depends on both irradiation and stimulation temperature while the RL signal is effected only by the irradiation temperature. The initial OSL signal is increasing with temperature whereas the total OSL area is decreasing. Therefore, if the irradiation temperature is kept constant, one can find an integration time which provides an OSL signal independent of stimulation temperature. Overall, the RL and OSL signals vary between -0.2 to 0.6% per C. Thermal effects were simulated with a band structure model and indicated that the temperature effects are caused by the combined efforts of energetic shallow traps and thermal excitation from intermediate states in deeper traps. In the study of ionization density, we investigated protons with energies between 10 and 60 MeV (4.57 to 1.08 keV/μm in water). Experimentally, we observed that the initial OSL signalprovided a signal independent of linear energy transfer (LET) for allenergies at 0.3 Gy. The total OSL area showed an LET dependent behavior atall doses and energies. We used track structure theory (TST) to give possible explanations for the LET dependence of the OSL signal. From these calculations, we found that the initial OSL signal is, in general, not LET independent which makes Al2O3:C unsuitable for OSL proton dosimetry. The initial OSL signal can, however

  10. CONNECTION BETWEEN THE ACCRETION DISK AND JET IN THE RADIO GALAXY 3C 111

    International Nuclear Information System (INIS)

    Chatterjee, Ritaban; Marscher, Alan P.; Jorstad, Svetlana G.; Harrison, Brandon; Agudo, Ivan; Taylor, Brian W.; Markowitz, Alex; Rivers, Elizabeth; Rothschild, Richard E.; McHardy, Ian M.; Aller, Margo F.; Aller, Hugh D.; Laehteenmaeki, Anne; Tornikoski, Merja; Gomez, Jose L.; Gurwell, Mark

    2011-01-01

    We present the results of extensive multi-frequency monitoring of the radio galaxy 3C 111 between 2004 and 2010 at X-ray (2.4-10 keV), optical (R band), and radio (14.5, 37, and 230 GHz) wave bands, as well as multi-epoch imaging with the Very Long Baseline Array (VLBA) at 43 GHz. Over the six years of observation, significant dips in the X-ray light curve are followed by ejections of bright superluminal knots in the VLBA images. This shows a clear connection between the radiative state near the black hole, where the X-rays are produced, and events in the jet. The X-ray continuum flux and Fe line intensity are strongly correlated, with a time lag shorter than 90 days and consistent with zero. This implies that the Fe line is generated within 90 lt-day of the source of the X-ray continuum. The power spectral density function of X-ray variations contains a break, with a steeper slope at shorter timescales. The break timescale of 13 +12 -6 days is commensurate with scaling according to the mass of the central black hole based on observations of Seyfert galaxies and black hole X-ray binaries (BHXRBs). The data are consistent with the standard paradigm, in which the X-rays are predominantly produced by inverse Compton scattering of thermal optical/UV seed photons from the accretion disk by a distribution of hot electrons-the corona-situated near the disk. Most of the optical emission is generated in the accretion disk due to reprocessing of the X-ray emission. The relationships that we have uncovered between the accretion disk and the jet in 3C 111, as well as in the Fanaroff-Riley class I radio galaxy 3C 120 in a previous paper, support the paradigm that active galactic nuclei and Galactic BHXRBs are fundamentally similar, with characteristic time and size scales proportional to the mass of the central black hole.

  11. Dealing with the sulfur part of cysteine: four enzymatic steps degrade l-cysteine to pyruvate and thiosulfate in Arabidopsis mitochondria.

    Science.gov (United States)

    Höfler, Saskia; Lorenz, Christin; Busch, Tjorven; Brinkkötter, Mascha; Tohge, Takayuki; Fernie, Alisdair R; Braun, Hans-Peter; Hildebrandt, Tatjana M

    2016-07-01

    Amino acid catabolism is essential for adjusting pool sizes of free amino acids and takes part in energy production as well as nutrient remobilization. The carbon skeletons are generally converted to precursors or intermediates of the tricarboxylic acid cycle. In the case of cysteine, the reduced sulfur derived from the thiol group also has to be oxidized in order to prevent accumulation to toxic concentrations. Here we present a mitochondrial sulfur catabolic pathway catalyzing the complete oxidation of l-cysteine to pyruvate and thiosulfate. After transamination to 3-mercaptopyruvate, the sulfhydryl group from l-cysteine is transferred to glutathione by sulfurtransferase 1 and oxidized to sulfite by the sulfur dioxygenase ETHE1. Sulfite is then converted to thiosulfate by addition of a second persulfide group by sulfurtransferase 1. This pathway is most relevant during early embryo development and for vegetative growth under light-limiting conditions. Characterization of a double mutant produced from Arabidopsis thaliana T-DNA insertion lines for ETHE1 and sulfurtransferase 1 revealed that an intermediate of the ETHE1 dependent pathway, most likely a persulfide, interferes with amino acid catabolism and induces early senescence. © 2016 Scandinavian Plant Physiology Society.

  12. Exercise induced upregulation of glutamate-cysteine ligase catalytic subunit and glutamate-cysteine ligase modifier subunit gene expression in Thoroughbred horses

    Directory of Open Access Journals (Sweden)

    Jeong-Woong Park

    2017-05-01

    Full Text Available Objective This study was performed to reveal the molecular structure and expression patterns of horse glutamate-cysteine ligase catalytic subunit (GCLC and glutamate-cysteine ligase modifier subunit (GCLM genes whose products form glutamate cysteine ligase, which were identified as differentially expressed genes in the previous study. Methods We performed bioinformatics analyses, and gene expression assay with quantitative polymerase chain reaction (qPCR for horse GCLC and GCLM genes in muscle and blood leukocytes of Thoroughbred horses Results Expression of GCLC showed the same pattern in both blood and muscle tissues after exercise. Expression of GCLC increased in the muscle and blood of Thoroughbreds, suggesting a tissue-specific regulatory mechanism for the expression of GCLC. In addition, expression of the GCLM gene increased after exercise in both the blood and muscle of Thoroughbreds. Conclusion We established the expression patterns of GCLC and GCLM in the skeletal muscle and blood of Thoroughbred horses in response to exercise. Further study is now warranted to uncover the functional importance of these genes in exercise and recovery in racehorses.

  13. Inherent Electrochemistry and Charge Transfer Properties of Few-Layer Two Dimensional Ti3C2Tx MXene

    KAUST Repository

    Nayak, Pranati

    2018-05-25

    We report the effect of Ti3C2Tx MXene flake thickness on its inherent electrochemistry and heterogeneous charge transfer characteristics. It is shown that the Ti3C2Tx undergoes irreversible oxidation in the positive potential window, which strongly depends on the flake thickness and pH of the electrolyte. Few-layer Ti3C2Tx exhibits faster electron transfer kinetics (k0=0.09533 cm/s) with Fe(CN)64−/3− redox mediator compared to multi-layer Ti3C2Tx (k0= 0.00503 cm/s). In addition, few-layer free standing Ti3C2Tx film electrode remains intact after enduring irreversible oxidation.

  14. Growth of high-quality hexagonal InN on 3C-SiC (001) by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Yaguchi, Hiroyuki; Hijikata, Yasuto; Yoshida, Sadafumi; Kitamura, Yoshihiro; Nishida, Kenji; Iwahashi, Yohei

    2005-01-01

    We have grown hexagonal InN (h-InN) films on 3C-SiC (001) substrates by RF-N 2 plasma molecular beam epitaxy taking account of small lattice mismatch between h-InN (10-10) and 3C-SiC (110). It was found from X-ray diffraction (XRD) measurements that h-InN grows with h-InN (0001) vertical stroke vertical stroke 3C-SiC (001) and h-InN (1-100) vertical stroke vertical stroke 3C-SiC (110). XRD measurements also revealed that the h-InN epitaxial layers grown on 3C-SiC (001) are composed of single domain. Strong and sharp photoluminescence from the h-InN was clearly observed at around 0.69 eV. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Inherent Electrochemistry and Charge Transfer Properties of Few-Layer Two Dimensional Ti3C2Tx MXene

    KAUST Repository

    Nayak, Pranati; Jiang, Qiu; Mohanraman, Rajeshkumar; Anjum, Dalaver H.; Hedhili, Mohamed N.; Alshareef, Husam N.

    2018-01-01

    We report the effect of Ti3C2Tx MXene flake thickness on its inherent electrochemistry and heterogeneous charge transfer characteristics. It is shown that the Ti3C2Tx undergoes irreversible oxidation in the positive potential window, which strongly depends on the flake thickness and pH of the electrolyte. Few-layer Ti3C2Tx exhibits faster electron transfer kinetics (k0=0.09533 cm/s) with Fe(CN)64−/3− redox mediator compared to multi-layer Ti3C2Tx (k0= 0.00503 cm/s). In addition, few-layer free standing Ti3C2Tx film electrode remains intact after enduring irreversible oxidation.

  16. Equation of State of Fe3C and Implications for the Carbon Content of Earth's Core

    Science.gov (United States)

    Davis, A.; Brauser, N.; Thompson, E. C.; Chidester, B.; Greenberg, E.; Prakapenka, V. B.; Campbell, A.

    2017-12-01

    Carbon is a common component in protoplanetary cores, as represented by iron meteorites. Therefore, along with silicon, oxygen, and other light elements, it is likely to be an alloying component with iron in Earth's core. Previous studies of the densities of iron carbides have not reached the combined pressure and temperature conditions relevant to Earth's core. To better understand the geophysical implications of carbon addition to Earth's core, we report P-V-T measurements of Fe3C to pressures and temperatures exceeding 110 GPa and 2500 K, using synchrotron X-ray diffraction in a laser heated diamond anvil cell. Fitting these measurements to an equation of state and assuming 1.5% density change upon melting and a 4000 K core-mantle boundary temperature, we report a value of 6 wt% carbon necessary to match the PREM density in the outer core. This value should be considered an upper bound due to the likely presence of other light elements.

  17. Microscale fracture mechanisms of a Cr3C2-NiCr HVOF coating

    International Nuclear Information System (INIS)

    Robertson, Andrew L.; White, Ken W.

    2017-01-01

    Thermal spray coatings, often composed of heterogeneous, multiphase microstructures, may, consequently, exhibit complex fracture behavior. For such coating structures, conventional mechanical evaluation methods fail to isolate the contribution of microstructural features to the overall fracture behavior. For this reason, this study employed focused ion beam machined (FIB) microcantilever beams and FIB sectioning methods to study the fracture mechanisms important at the scale of the heterogeneous Cr 3 C 2 -NiCr thermal spray coating. We found three fracture modes, namely, intergranular matrix fracture, matrix/carbide interfacial fracture, and carbide cleavage. By comparison, microindentation-induced cracks, the frequency of crack deflection around carbides is significantly more prevalent at this much larger crack dimension. This mechanistic variation provides some insight into the specific role and limitations of the microcantilever beam technique for fracture characterization of composite microstructures.

  18. Probing the connection between the accretion disk, outflows and the jet in 3C111

    Science.gov (United States)

    Tombesi, Francesco

    2011-10-01

    Recent XMM-Newton and Suzaku observations of 3C111 demonstrated the presence of ultra-fast outflows (UFOs) with v~0.1c and their relation with the accretion disk. Independent studies found that X-ray dips are followed by ejection of superluminal radio knots, therefore providing a proof of the disk-jet connection. We acquired evidence that UFOs are preferentially present between X-ray dips and new knots, possibly indicating also a link between disk outflows and the jet. The goal of this XMM-Newton proposal is to confirm this evidence. Given the strong correlation with X-rays, we will use an ongoing optical monitoring campaign to trigger a 90ks observation within two days of a dip to detect a UFO and we request a possible additional 60ks >15 days after to compare with the non-dipped state.

  19. The L3+C detector, a unique tool-set to study cosmic rays

    International Nuclear Information System (INIS)

    Adriani, O.; Akker, M. van den; Banerjee, S.; Baehr, J.; Betev, B.; Bourilkov, D.; Bottai, S.; Bobbink, G.; Cartacci, A.; Chemarin, M.; Chen, G.; Chen, H.S.; Chiarusi, T.; Dai, C.J.; Ding, L.K.; Duran, I.; Faber, G.; Fay, J.; Grabosch, H.J.; Groenstege, H.; Guo, Y.N.; Gupta, S.; Haller, Ch.; Hayashi, Y.; He, Z.X.; Hebbeker, T.; Hofer, H.; Hoferjun, H.; Huo, A.X.; Ito, N.; Jing, C.L.; Jones, L.; Kantserov, V.; Kawakami, S.; Kittel, W.; Koenig, A.C.; Kok, E.; Korn, A.; Kuang, H.H.; Kuijpers, J.; Ladron de Guevara, P.; Le Coultre, P.; Lei, Y.; Leich, H.; Leiste, R.; Li, D.; Li, L.; Li, Z.C.; Liu, Z.A.; Liu, H.T.; Lohmann, W.; Lu, Y.S.; Ma, X.H.; Ma, Y.Q.; Mil, A. van; Monteleoni, B.; Nahnhauer, R.; Pauss, F.; Parriaud, J.-F.; Petersen, B.; Pohl, M.; Qing, C.R.; Ramelli, R.; Ravindran, K.C.; Rewiersma, P.; Rojkov, A.; Saidi, R.; Schmitt, V.; Schoeneich, B.; Schotanus, D.J.; Shen, C.Q.; Sulanke, H.; Tang, X.W.; Timmermans, C.; Tonwar, S.; Trowitzsch, G.; Unger, M.; Verkooijen, H.; Wang, X.L.; Wang, X.W.; Wang, Z.M.; Wijk, R. van; Wijnen, Th.A.M.; Wilkens, H.; Xu, Y.P.; Xu, Z.Z.; Yang, C.G.; Yang, X.F.; Yao, Z.G.; Yu, Z.Q.; Zhang, S.; Zhu, G.Y.; Zhu, Q.Q.; Zhuang, H.L.; Zwart, A.N.M.

    2002-01-01

    The L3 detector at the CERN electron-positron collider, LEP, has been employed for the study of cosmic ray muons. The muon spectrometer of L3 consists of a set of high-precision drift chambers installed inside a magnet with a volume of about 1000 m 3 and a field of 0.5 T. Muon momenta are measured with a resolution of a few percent at 50 GeV. The detector is located under 30 m of overburden. A scintillator air shower array of 54 m by 30 m is installed on the roof of the surface hall above L3 in order to estimate the energy and the core position of the shower associated with a sample of detected muons. Thanks to the unique properties of the L3+C detector, muon research topics relevant to various current problems in cosmic ray and particle astrophysics can be studied

  20. The L3+C detector, a unique tool-set to study cosmic rays

    CERN Document Server

    Adriani, O; Banerjee, S; Bähr, J; Betev, B L; Bourilkov, D; Bottai, S; Bobbink, Gerjan J; Cartacci, A M; Chemarin, M; Chen, G; Chen He Sheng; Chiarusi, T; Dai Chang Jiang; Ding, L K

    2002-01-01

    The L3 detector at the CERN electron-positron collider, LEP, has been employed for the study of cosmic ray muons. The muon spectrometer of L3 consists of a set of high-precision drift chambers installed inside a magnet with a volume of about 1000 m**3 and a field of 0.5 T. Muon momenta are measured with a resolution of a few percent at 50 GeV. The detector is located under 30 m of overburden. A scintillator air shower array of 54 m by 30 m is installed on the roof of the surface hall above L3 in order to estimate the energy and the core position of the shower associated with a sample of detected muons. Thanks to the unique properties of the L3+C detector, muon research topics relevant to various current problems in cosmic ray and particle astrophysics can be studied.

  1. Total synthesis of ciguatoxin and 51-hydroxyCTX3C.

    Science.gov (United States)

    Inoue, Masayuki; Miyazaki, Keisuke; Ishihara, Yuuki; Tatami, Atsushi; Ohnuma, Yuyu; Kawada, Yuuya; Komano, Kazuo; Yamashita, Shuji; Lee, Nayoung; Hirama, Masahiro

    2006-07-26

    Ciguatoxins, the principal causative toxins of ciguatera seafood poisoning, are large ladder-like polycyclic ethers with the 13 ether rings ranging from five- to nine-membered. In this paper, we describe the total synthesis of the two most toxic members of the ciguatoxin family, ciguatoxin 1 and 51-hydroxyCTX3C 2, based on a unified synthetic strategy. The key features in our syntheses were (i) direct construction of the O,S-acetal from the corresponding left and right wing fragments (3, 4, 14); (ii) stereo- and chemoselective radical reaction of the alpha-oxyradical with pentafluorophenyl acrylate to achieve cyclization of the seven-membered G-ring; (iii) ring-closing metathesis reaction to build the nine-membered F-ring; and (iv) an efficient protective group strategy using the oxidatively removable 2-naphthylmethyl groups.

  2. Production of monoclonal antibodies for sandwich immunoassay detection of ciguatoxin 51-hydroxyCTX3C.

    Science.gov (United States)

    Tsumuraya, Takeshi; Fujii, Ikuo; Inoue, Masayuki; Tatami, Atsushi; Miyazaki, Keisuke; Hirama, Masahiro

    2006-09-01

    Every year, more than 50,000 people in subtropical and tropical regions suffer from ciguatera seafood poisoning. The extremely low level of the causative neurotoxins (ciguatoxins) in fish has hampered the preparation of antibodies for detection of the toxins. In this study, we produced a monoclonal antibody (8H4) against the right end of ciguatoxin CTX1B (1) and 51-hydroxyCTX3C (3) by immunizing mice with the keyhole limpet hemocyanin-conjugate of the synthetic HIJKLM ring fragment (10). We used 8H4 and another previously reported monoclonal antibody (10C9) that recognizes the left end of 3 to develop a sandwich enzyme-linked immunosorbent assay (ELISA) to detect 3. The assay could detect 3 down to the ppb level and lacked cross-reactivity with other related marine toxins, including brevetoxin A, brevetoxin B, okadaic acid, and maitotoxin.

  3. Magnetic properties of {alpha}-Fe and Fe{sub 3}C nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, M U; Weissker, U; Wolny, F; Mueller, C; Loeffler, M; Muehl, T; Leonhardt, A; Buechner, B; Klingeler, R, E-mail: m.lutz@ifw-dresden.d [Leibniz Institute for Solid State and Materials Research IFW Dresden, Helmholtzstrasse 20, 01069 Dresden (Germany)

    2010-01-01

    The magnetic properties of single domain {alpha}-Fe and Fe{sub 3}C nanowires encapsulated within Multi Walled Carbon Nanotubes (MWNT) are investigated with a Magnetic Force Microscope (MFM). The wires are formed during the Chemical Vapour Deposition growth process, partially filling the hollow center of the MWNTs. The wires have a diameter variation of 10-60nm and can be several {mu}m long. The phase and crystal orientation of the filling relative to the long tube axis are probed by Transmission Electron Microscopy. The remanent magnetization states of the wires are investigated by MFM imaging. The {alpha}-Fe wires show shape dominated magnetization along the tube axis, whereas the FesC wires show a perpendicular magnetization imposed by magneto-crystalline anisotropy. Switching fields of {alpha}-Fe nanowires are determined by the application of an in-situ magnetic field, revealing a tip triggered magnetization reversal by localized nucleation.

  4. Equipartition Jet Model for the Seyfert 1 Galaxy 3C120

    Directory of Open Access Journals (Sweden)

    Siek Hyung

    2003-09-01

    Full Text Available The motion of 3C120 Jet relative to the core is reasonably uniform and the VLBI scale jet connects outwards to a VLA ˜ 100 kpc scale. We measured the jet width variation from the center and found some indication of a power law which indicates the jet expands roughly with a constant opening angle and a constant flow velocity, Vf \\cong c, from subparsec scales to ˜ 100 kpc. With such a constant flow velocity and based on other physical parameters deduced from observed emission characteristics of the jet, we have established an equipartition jet model which might accommodate the basic parameters of the jet on subparsec scales, with which one can fit the radio intensities over all the scale of the jet even to ˜ 100 kpc.

  5. OPTICAL MONITORING OF THE BROAD-LINE RADIO GALAXY 3C 390.3

    International Nuclear Information System (INIS)

    Dietrich, Matthias; Peterson, Bradley M.; Grier, Catherine J.; Bentz, Misty C.; Eastman, Jason; Frank, Stephan; Gonzalez, Raymond; Marshall, Jennifer L.; DePoy, Darren L.; Prieto, Jose L.

    2012-01-01

    We have undertaken a new ground-based monitoring campaign on the broad-line radio galaxy 3C 390.3 to improve the measurement of the size of the broad emission-line region and to estimate the black hole mass. Optical spectra and g-band images were observed in late 2005 for three months using the 2.4 m telescope at MDM Observatory. Integrated emission-line flux variations were measured for the hydrogen Balmer lines Hα, Hβ, Hγ, and for the helium line He IIλ4686, as well as g-band fluxes and the optical active galactic nucleus (AGN) continuum at λ = 5100 Å. The g-band fluxes and the optical AGN continuum vary simultaneously within the uncertainties, τ cent (0.2 ± 1.1) days. We find that the emission-line variations are delayed with respect to the variable g-band continuum by τ(Hα) 56.3 +2.4 –6.6 days, τ(Hβ) = 44.3 +3.0 –3.3 days, τ(Hγ) = 58.1 +4.3 –6.1 days, and τ(He II 4686) = 22.3 +6.5 –3.8 days. The blue and red peaks in the double-peaked line profiles, as well as the blue and red outer profile wings, vary simultaneously within ±3 days. This provides strong support for gravitationally bound orbital motion of the dominant part of the line-emitting gas. Combining the time delay of the strong Balmer emission lines of Hα and Hβ and the separation of the blue and red peaks in the broad double-peaked profiles in their rms spectra, we determine M vir bh = 1.77 +0.29 –0.31 × 10 8 M ☉ and using σ line of the rms spectra M vir bh 2.60 +0.23 –0.31 × 10 8 M ☉ for the central black hole of 3C 390.3, respectively. Using the inclination angle of the line-emitting region which is measured from superluminal motion detected in the radio range, accretion disk models to fit the optical double-peaked emission-line profiles, and X-ray observations, the mass of the black hole amounts to M bh = 0.86 +0.19 –0.18 × 10 9 M ☉ (peak separation) and M bh 1.26 +0.21 –0.16 × 10 9 M ☉ (σ line ), respectively. This result is consistent with the black

  6. RADIOASTRON OBSERVATIONS OF THE QUASAR 3C273: A CHALLENGE TO THE BRIGHTNESS TEMPERATURE LIMIT

    Energy Technology Data Exchange (ETDEWEB)

    Kovalev, Y. Y.; Kardashev, N. S.; Voitsik, P. A.; Kovalev, Yu. A.; Lisakov, M. M.; Sokolovsky, K. V. [Astro Space Center of Lebedev Physical Institute, Profsoyuznaya 84/32, 117997 Moscow (Russian Federation); Kellermann, K. I. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Lobanov, A. P.; Zensus, J. A.; Anderson, J. M.; Bach, U.; Kraus, A. [Max-Planck-Institute for Radio Astronomy, Auf dem Hügel 69, D-53121 (Germany); Johnson, M. D. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Gurvits, L. I. [Joint Institute for VLBI ERIC, P.O. Box 2, 7990 AA Dwingeloo (Netherlands); Jauncey, D. L. [CSIRO Astronomy and Space Sciences, Epping, NSW 1710 (Australia); Ghigo, F. [National Radio Astronomy Observatory, Rt. 28/92, Green Bank, WV 24944-0002 (United States); Ghosh, T.; Salter, C. J. [Arecibo Observatory, NAIC, HC3 Box 53995, Arecibo, Puerto Rico, PR 00612 (United States); Petrov, L. Yu. [Astrogeo Center, 7312 Sportsman Drive, Falls Church, VA 22043 (United States); Romney, J. D. [National Radio Astronomy Observatory, P.O. Box O, 1003 Lopezville Road, Socorro, NM 87801-0387 (United States)

    2016-03-20

    Inverse Compton cooling limits the brightness temperature of the radiating plasma to a maximum of 10{sup 11.5} K. Relativistic boosting can increase its observed value, but apparent brightness temperatures much in excess of 10{sup 13} K are inaccessible using ground-based very long baseline interferometry (VLBI) at any wavelength. We present observations of the quasar 3C 273, made with the space VLBI mission RadioAstron on baselines up to 171,000 km, which directly reveal the presence of angular structure as small as 26 μas (2.7 light months) and brightness temperature in excess of 10{sup 13} K. These measurements challenge our understanding of the non-thermal continuum emission in the vicinity of supermassive black holes and require a much higher Doppler factor than what is determined from jet apparent kinematics.

  7. OPTICAL MONITORING OF THE BROAD-LINE RADIO GALAXY 3C 390.3

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, Matthias; Peterson, Bradley M.; Grier, Catherine J.; Bentz, Misty C.; Eastman, Jason; Frank, Stephan; Gonzalez, Raymond; Marshall, Jennifer L.; DePoy, Darren L.; Prieto, Jose L., E-mail: dietrich@astronomy.ohio-state.edu [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)

    2012-09-20

    We have undertaken a new ground-based monitoring campaign on the broad-line radio galaxy 3C 390.3 to improve the measurement of the size of the broad emission-line region and to estimate the black hole mass. Optical spectra and g-band images were observed in late 2005 for three months using the 2.4 m telescope at MDM Observatory. Integrated emission-line flux variations were measured for the hydrogen Balmer lines H{alpha}, H{beta}, H{gamma}, and for the helium line He II{lambda}4686, as well as g-band fluxes and the optical active galactic nucleus (AGN) continuum at {lambda} = 5100 A. The g-band fluxes and the optical AGN continuum vary simultaneously within the uncertainties, {tau}{sub cent} (0.2 {+-} 1.1) days. We find that the emission-line variations are delayed with respect to the variable g-band continuum by {tau}(H{alpha}) 56.3{sup +2.4}{sub -6.6} days, {tau}(H{beta}) = 44.3{sup +3.0}{sub -3.3} days, {tau}(H{gamma}) = 58.1{sup +4.3}{sub -6.1} days, and {tau}(He II 4686) = 22.3{sup +6.5}{sub -3.8} days. The blue and red peaks in the double-peaked line profiles, as well as the blue and red outer profile wings, vary simultaneously within {+-}3 days. This provides strong support for gravitationally bound orbital motion of the dominant part of the line-emitting gas. Combining the time delay of the strong Balmer emission lines of H{alpha} and H{beta} and the separation of the blue and red peaks in the broad double-peaked profiles in their rms spectra, we determine M {sup vir}{sub bh} = 1.77{sup +0.29}{sub -0.31} Multiplication-Sign 10{sup 8} M{sub Sun} and using {sigma}{sub line} of the rms spectra M {sup vir}{sub bh} 2.60{sup +0.23}{sub -0.31} Multiplication-Sign 10{sup 8} M{sub Sun} for the central black hole of 3C 390.3, respectively. Using the inclination angle of the line-emitting region which is measured from superluminal motion detected in the radio range, accretion disk models to fit the optical double-peaked emission-line profiles, and X-ray observations

  8. A cosmic double helix in the archetypical quasar 3C273.

    Science.gov (United States)

    Lobanov, A P; Zensus, J A

    2001-10-05

    Finding direct evidence for plasma instability in extragalactic jets is crucial for understanding the nature of relativistic outflows from active galactic nuclei. Our radio interferometric observations of the quasar 3C273 made with the orbiting radio telescope, HALCA, and an array of ground telescopes have yielded an image in which the emission across the jet is resolved, revealing two threadlike patterns that form a double helix inside the jet. This double helical structure is consistent with a Kelvin-Helmholtz instability, and at least five different instability modes can be identified and modeled by a light jet with a Lorentz factor of 2 and Mach number of 3.5. The model reproduces in detail the internal structure of the jet on scales of up to 30 milli-arc seconds ( approximately 300 parsecs) and is consistent with the general morphology of the jet on scales of up to 1 kiloparsec.

  9. Spectroscopic observations of the supernova remnant candidates 3 C 400.2 and S91

    International Nuclear Information System (INIS)

    Sabbadin, F.; D'Odorico, S.

    1976-01-01

    Spectra of 3 C 400.2 and S 91 have been used to measure the emission line rations Hα/N II region, Hα/ SII region and 6,717/6,731 of S II region in the two nebulae. By comparing the measured ratios with the mean values observed in supernova remnants, in planetary nebulae und in glactic H II regions, it is possible to conclude that the two nebulae are the result of supernova explosions. For S 91, previously catalogued as an H II region, we derive a linear diameter of 34 pc and a distance of 0.7 kpc using a relation between the diameter of supernova remnants and the average Hα/ N II region intensity ratio in their optical filaments. (orig.) [de

  10. Sample dependent correlation between TL and LM-OSL in Al2O3:C

    International Nuclear Information System (INIS)

    Dallas, G.I.; Polymeris, G.S.; Stefanaki, E.C.; Afouxenidis, D.; Tsirliganis, N.C.; Kitis, G.

    2008-01-01

    Al 2 O 3 :C single crystals are known to exhibit different, sample dependent, glow-curve shapes. The relation between the Thermoluminescence (TL) traps and the linear modulated optically stimulation luminescence (LM-OSL) traps is of high importance. In the present work a correlation study is attempted using 23 single crystals with dimensions between 400 and 500μm. The correlation study involved two steps. In the first step, both TL glow curves and LM-OSL decay curves are deconvoluted and a one-to-one correlation between TL peaks and LM-OSL components is attempted. In the second step the TL glow-curves are corrected for thermal quenching, the corrected curves are deconvoluted and a new correlation between TL and LM-OSL individual components is performed

  11. Thermally assisted OSL from deep traps in Al2O3:C

    International Nuclear Information System (INIS)

    Polymeris, G.S.; Raptis, S.; Afouxenidis, D.; Tsirliganis, N.C.; Kitis, G.

    2010-01-01

    The present work suggests an alternative experimental method in order to not only measure the signal of the deep traps in Al 2 O 3 :C without heating the sample to temperatures greater than 500 o C, but also use this signal for high dose level dosimetry purposes as well. This method consists of photo transfer OSL measurements performed at elevated temperatures using the blue LEDs (470 nm, FWHM 20 nm) housed at commercial Riso TL/OSL systems, after the sample was previously heated up to 500 o C in order to empty its main TL dosimetric trap. The influence of this procedure on specific features such as glow curve shape and sensitivity of the main TL glow peak was also studied.

  12. An Orientation-Based Unification of Young Jetted AGN: The Case of 3C 286

    Energy Technology Data Exchange (ETDEWEB)

    Berton, Marco [Dipartimento di Fisica e Astronomia “G. Galilei,” Università di Padova, Padova (Italy); Brera Astronomical Observatory (INAF), Merate (Italy); Foschini, Luigi; Caccianiga, Alessandro [Brera Astronomical Observatory (INAF), Merate (Italy); Ciroi, Stefano [Dipartimento di Fisica e Astronomia “G. Galilei,” Università di Padova, Padova (Italy); Congiu, Enrico [Dipartimento di Fisica e Astronomia “G. Galilei,” Università di Padova, Padova (Italy); Brera Astronomical Observatory (INAF), Merate (Italy); Cracco, Valentina; Frezzato, Michele; La Mura, Giovanni; Rafanelli, Piero, E-mail: marco.berton@unipd.it [Dipartimento di Fisica e Astronomia “G. Galilei,” Università di Padova, Padova (Italy)

    2017-07-25

    In recent years, the old paradigm according to which only high-mass black holes can launch powerful relativistic jets in active galactic nuclei (AGN) has begun to crumble. The discovery of γ-rays coming from narrow-line Seyfert 1 galaxies (NLS1s), usually considered young and growing AGN harboring a central black hole with mass typically lower than 10{sup 8} M{sub ⊙}, indicated that also these low-mass AGN can produce powerful relativistic jets. The search for parent population of γ-ray emitting NLS1s revealed their connection with compact steep-spectrum sources (CSS). In this proceeding we present a review of the current knowledge of these sources, we present the new important case of 3C 286, classified here for the fist time as NLS1, and we finally provide a tentative orientation based unification of NLS1s and CSS sources.

  13. An Orientation-Based Unification of Young Jetted AGN: The Case of 3C 286

    International Nuclear Information System (INIS)

    Berton, Marco; Foschini, Luigi; Caccianiga, Alessandro; Ciroi, Stefano; Congiu, Enrico; Cracco, Valentina; Frezzato, Michele; La Mura, Giovanni; Rafanelli, Piero

    2017-01-01

    In recent years, the old paradigm according to which only high-mass black holes can launch powerful relativistic jets in active galactic nuclei (AGN) has begun to crumble. The discovery of γ-rays coming from narrow-line Seyfert 1 galaxies (NLS1s), usually considered young and growing AGN harboring a central black hole with mass typically lower than 10 8 M ⊙ , indicated that also these low-mass AGN can produce powerful relativistic jets. The search for parent population of γ-ray emitting NLS1s revealed their connection with compact steep-spectrum sources (CSS). In this proceeding we present a review of the current knowledge of these sources, we present the new important case of 3C 286, classified here for the fist time as NLS1, and we finally provide a tentative orientation based unification of NLS1s and CSS sources.

  14. Rapid infrared and optical variability in the bright quasar 3C273

    International Nuclear Information System (INIS)

    Courvoisier, T.J.-L.; Robson, E.I.; Hughes, D.H.; Bouchet, P.; Schwarz, H.E.; Krisciunas, K.

    1988-01-01

    We have observed variations by a factor of two in the infrared flux from the bright quasar 3C273 on a timescale as short as one day. In February 1988, the behaviour of the source changed from having a stable infrared flux and slow optical variations to a state characterized by recurrent infrared and optical flaring. The optical variations were of several per cent per day, changing from increase to decrease approximately every week. The amplitude of the repeated optical flares was 30-40%. The data are consistent with re-injection/acceleration of electrons followed by rapid cooling. The inferred magnetic field is 0.7 gauss and the data are marginally consistent with no relativistic beaming. (author)

  15. Point defect thermodynamics and diffusion in Fe3C: A first-principles study

    International Nuclear Information System (INIS)

    Chao Jiang; Uberuaga, B.P.; Srinivasan, S.G.

    2008-01-01

    The point defect structure of cementite (Fe 3 C) is investigated using a combination of the statistical mechanical Wagner-Schottky model and first-principles calculations within the generalized gradient approximation. Large 128-atom supercells are employed to obtain fully converged point defect formation energies. The present study unambiguously shows that carbon vacancies and octahedral carbon interstitials are the structural defects in C-depleted and C-rich cementite, respectively. The dominant thermal defects in C-depleted and stoichiometric cementite are found to be carbon Frenkel pairs. In C-rich cementite, however, the primary thermal excitations are strongly temperature-dependent: interbranch, Schottky and Frenkel defects dominate successively with increasing temperature. Using the nudged elastic band technique, the migration barriers of major point defects in cementite are also determined and compared with available experiments in the literature

  16. Orbit determination using real tracking data from FY3C-GNOS

    Science.gov (United States)

    Xiong, Chao; Lu, Chuanfang; Zhu, Jun; Ding, Huoping

    2017-08-01

    China is currently developing the BeiDou Navigation Satellite System, also known as BDS. The nominal constellation of BDS (regional), which had been able to provide preliminary regional positioning and navigation functions, was composed of fourteen satellites, including 5 GEO, 5 IGSO and 4 MEO satellites, and was realized by the end of 2013. Global navigation satellite system occultation sounder (GNOS) on board the Fengyun3C (FY3C) satellite, which is the first BDS/GPS compatible radio occultation (RO) sounder in the world, was launched on 23 September 2013. The GNOS instrument is capable of tracking up to 6 BeiDou satellites and more than 8 GPS satellites. We first present a quality analysis using 1-week onboard BDS/GPS measurements collected by GNOS. Satellite visibility, multipath combination and the ratio of cycle slips are analyzed. The analysis of satellite visibility shows that for one week the BDS receiver can track up to 6 healthy satellites. The analysis of multipath combinations (MPC) suggests more multipath present for BDS than GPS for the CA code (B1 MPC is 0.597 m, L1 MPC is 0.326 m), but less multipath for the P code (B2 MPC is 0.421 m, L2 MPC is 0.673 m). More cycle slips occur for the BDS than for the GPS receiver as shown by the ratio of total satellites/cycle slips observed over a 24 h period. Both the maximum value and average of the ratio of cycle slips based on BDS measurements is 72/50.29, which is smaller than 368/278.71 based on GPS measurements. Second, the results of reduced dynamic orbit determination using BDS/GPS code and phase measurements, standalone BDS SPP (Single Point Positioning) kinematic solution and real-time orbit determination using BDS/GPS code measurements are presented and analyzed. Using an overlap analysis, the orbit consistency of FY3C-GNOS is about 3.80 cm. The precision of BDS only solutions is about 22 cm. The precision of FY3C-GNOS orbit with the Helmert variance component estimation are improved slightly after

  17. Soft X-ray observations of the supernova remnants HB 3 and 3C 58

    Science.gov (United States)

    Galas, C. M. F.; Tuohy, I. R.; Garmire, G. P.

    1980-01-01

    The HEAO 1 A-2 low energy detectors have discovered soft X-ray emission from a source positionally coincident with the supernova remnant HB 3. The flux in the energy range 0.3-2.2 keV is about 6 x 10 to the -11th ergs per sq cm s. The spectral data are fitted to a hydrogen thermal bremsstrahlung model, and the physical parameters of the supernova remnant are estimated. The age derived is about 21,000 years, and the initial blast energy is about 3.1 x 10 to the 50th ergs. Upper limits to the soft X-ray flux and the luminosity of the supernova remnant 3 C 58 are also derived.

  18. Faraday rotation in jets of AGN: the case of 3C 120

    International Nuclear Information System (INIS)

    Gómez, José L; Roca-Sogorb, Mar; Agudo, Iván; Marscher, Alan P; Jorstad, Svetlana G

    2012-01-01

    The source of Faraday rotation in the jet of the radio galaxy 3C 120 is analyzed through Very Long Baseline Array observations carried out between 1999 and 2007 at 15, 22 and 43 GHz. Uncorrelated changes in the linear polarization of the underlying jet emission and the Faraday rotation screen indicate that the emitting jet and the source of Faraday rotation are not closely connected physically and have different configurations for the magnetic field and/or kinematical properties. Furthermore, the existence of a region of enhanced rotation measure whose properties remain constant over three years requires a localized source of Faraday rotation, favoring a model in which a significant fraction of the rotation measure originates in foreground clouds.

  19. Theoretical investigation on structural stability of InN thin films on 3C-SiC(0 0 1)

    International Nuclear Information System (INIS)

    Ito, Takumi; Akiyama, Toru; Nakamura, Kohji; Ito, Tomonori

    2008-01-01

    The structural stability of InN thin films on 3C-SiC(0 0 1) substrate is systematically investigated based on an empirical interatomic potential, which incorporates electrostatic energy due to covalent bond charges and ionic charges. The calculated energy differences among coherently grown 3C-InN(0 0 1), 3C-InN(0 0 1) with misfit dislocations (MDs), and 2H-InN(0 0 0 1) imply that the coherently grown 3C-InN(0 0 1) is stable when the film thickness is less than 7 monolayers (MLs) while 2H-InN(0 0 0 1) is stabilized for the thickness beyond 8 MLs. This is because InN layers in 2H-InN(0 0 0 1) are fully relaxed by one MD. The analysis of atomic configuration at the 3C-InN(0 0 1)/3C-SiC(0 0 1) interfaces reveals that the coordination number of interfacial atoms is quite different from that in the bulk region. Thus, 3C-InN(0 0 1) with MDs on 3C-SiC(0 0 1) is always metastable over entire range of film thickness, consistent with the successful fabrication of 2H-InN(0 0 0 1) on 3C-SiC(0 0 1) by the molecular beam epitaxy. These results suggest that the mismatch in atomic arrangements at the interface crucially affects the structural stability of InN thin films on 3C-SiC(0 0 1) substrate

  20. HPA axis dysregulation, NR3C1 polymorphisms and glucocorticoid receptor isoforms imbalance in metabolic syndrome.

    Science.gov (United States)

    Martins, Clarissa Silva; Elias, Daniel; Colli, Leandro Machado; Couri, Carlos Eduardo; Souza, Manoel Carlos L A; Moreira, Ayrton C; Foss, Milton C; Elias, Lucila L K; de Castro, Margaret

    2017-03-01

    Metabolic syndrome (MetS) shares several similarities with hypercortisolism. To evaluate hypothalamic-pituitary-adrenal (HPA) axis sensitivity to dexamethasone (DEX), NR3C1 single nucleotide polymorphisms (SNPs), and expression of glucocorticoid receptor (GR) isoforms and cytokines in peripheral immune cells of MetS patients and controls. Prospective study with 40 MetS patients and 40 controls was conducted at the Ribeirão Preto Medical School University Hospital. Plasma and salivary cortisol were measured in basal conditions and after 0.25, 0.5, and 1 mg of DEX given at 2300 h. In addition, p.N363S (rs6195), p.ER22/23EK (rs6189-6190), and BclI (rs41423247) SNPs were evaluated by quantitative polymerase chain reaction allelic discrimination. Exons 3 to 9 and exon/intron boundaries of NR3C1 were sequenced. GR isoforms and cytokines (IL1B, IL2, IL4, IL6, IL8, IL10, IFNγ, TNFα) expression were assessed by quantitative polymerase chain reaction. Plasma and salivary cortisol (nmol/L) after 1-mg DEX were higher in MetS patients compared with controls (PF: 70.2 ± 17.3 vs 37.9 ± 2.6, P = .02, and SF: 4.9 ± 1.7 vs 2.2 ± 0.3, P molecular mechanism of glucocorticoid resistance in MetS. Thus, HPA axis dysregulation might contribute to MetS pathogenesis. Copyright © 2016 John Wiley & Sons, Ltd.

  1. Electron paramagnetic resonance study on n-type electron-irradiated 3C-SiC

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, P; Rabia, K; Son, N T; Janzen, E [Department of Physics, Chemistry and Biology, Linkoeping University, SE-581 83 Linkoeping (Sweden); Ohshima, T; Morishita, N; Itoh, H [Japan Atomic Energy Research Institute, Takasaki 370-1292 (Japan); Isoya, J [University of Tsukuba, Tsukuba 305-8550 (Japan)], E-mail: paca@ifm.liu.se

    2008-03-15

    Electron Paramagnetic Resonance (EPR) was used to study defects in n-type 3C-SiC films irradiated by 3-MeV electrons at room temperature with a dose of 2x10{sup 18} cm{sup -2}. After electron irradiation, two new EPR spectra with an effective spin S = 1, labeled L5 and L6, were observed. The L5 center has C{sub 3v} symmetry with g = 2.004 and a fine-structure parameter D = 436.5x10{sup -4} cm{sup -1}. The L5 spectrum was only detected under light illumination and it could not be detected after annealing at {approx}550{sup 0}C. The principal z-axis of the D tensor is parallel to the <111>-directions, indicating the location of spins along the Si-C bonds. Judging from the symmetry and the fact that the signal was detected under illumination in n-type material, the L5 center may be related to the divacancy in the neutral charge state. The L6 center has a C{sub 2v}-symmetry with an isotropic g-value of g = 2.003 and the fine structure parameters D = 547.7x10{sup -4} cm{sup -1} and E = 56.2x10{sup -4} cm{sup -1}. The L6 center disappeared after annealing at a rather low temperature ({approx}200 deg. C), which is substantially lower than the known annealing temperatures for vacancy-related defects in 3C-SiC. This highly mobile defect may be related to carbon interstitials.

  2. Isolation and molecular characterization of cathepsin L-like cysteine protease cDNAs from Western flower thrips (Frankliniella occidentalis)

    NARCIS (Netherlands)

    Kuipers, A.G.J.; Jongsma, M.A.

    2004-01-01

    Cysteine proteases are predominant in thrips guts (TGs) and, therefore, a suitable target for selecting effective protease inhibitors against western flower thrips (Frankliniella occidentalis). We report the isolation of four full-length cysteine protease cDNA clones from thrips in a two-step PCR

  3. Participation of intracellular cysteine proteinases, in particular cathepsin B, in degradation of collagen in periosteal tissue explants

    NARCIS (Netherlands)

    Creemers, L. B.; Hoeben, K. A.; Jansen, D. C.; Buttle, D. J.; Beertsen, W.; Everts, V.

    1998-01-01

    The involvement of cysteine proteinases in the degradation of soft connective tissue collagen was studied in cultured periosteal explants. Using cysteine proteinase inhibitors that were active intracellularly or extracellularly (Ep453 and Ep475, respectively), it was shown that over-all collagen

  4. L-Cysteine inhibits root elongation through auxin/PLETHORA and SCR/SHR pathway in Arabidopsis thaliana.

    Science.gov (United States)

    Wang, Zhen; Mao, Jie-Li; Zhao, Ying-Jun; Li, Chuan-You; Xiang, Cheng-Bin

    2015-02-01

    L-Cysteine plays a prominent role in sulfur metabolism of plants. However, its role in root development is largely unknown. Here, we report that L-cysteine reduces primary root growth in a dosage-dependent manner. Elevating cellular L-cysteine level by exposing Arabidopsis thaliana seedlings to high L-cysteine, buthionine sulphoximine, or O-acetylserine leads to altered auxin maximum in root tips, the expression of quiescent center cell marker as well as the decrease of the auxin carriers PIN1, PIN2, PIN3, and PIN7 of primary roots. We also show that high L-cysteine significantly reduces the protein level of two sets of stem cell specific transcription factors PLETHORA1/2 and SCR/SHR. However, L-cysteine does not downregulate the transcript level of PINs, PLTs, or SCR/SHR, suggesting that an uncharacterized post-transcriptional mechanism may regulate the accumulation of PIN, PLT, and SCR/SHR proteins and auxin transport in the root tips. These results suggest that endogenous L-cysteine level acts to maintain root stem cell niche by regulating basal- and auxin-induced expression of PLT1/2 and SCR/SHR. L-Cysteine may serve as a link between sulfate assimilation and auxin in regulating root growth. © 2014 Institute of Botany, Chinese Academy of Sciences.

  5. Cysteine Addition Promotes Sulfide Production and 4-Fold Hg(II)-S Coordination in Actively Metabolizing Escherichia coli.

    Science.gov (United States)

    Thomas, Sara A; Gaillard, Jean-François

    2017-04-18

    The bacterial uptake of mercury(II), Hg(II), is believed to be energy-dependent and is enhanced by cysteine in diverse species of bacteria under aerobic and anaerobic conditions. To gain insight into this Hg(II) biouptake pathway, we have employed X-ray absorption spectroscopy (XAS) to investigate the relationship between exogenous cysteine, cellular metabolism, cellular localization, and Hg(II) coordination in aerobically respiring Escherichia coli (E. coli). We show that cells harvested in exponential growth phase consistently display mixtures of 2-fold and 4-fold Hg(II) coordination to sulfur (Hg-S 2 and Hg-S 4 ), with added cysteine enhancing Hg-S 4 formation. In contrast, cells in stationary growth phase or cells treated with a protonophore causing a decrease in cellular ATP predominantly contain Hg-S 2 , regardless of cysteine addition. Our XAS results favor metacinnabar (β-HgS) as the Hg-S 4 species, which we show is associated with both the cell envelope and cytoplasm. Additionally, we observe that added cysteine abiotically oxidizes to cystine and exponentially growing E. coli degrade high cysteine concentrations (100-1000 μM) into sulfide. Thermodynamic calculations confirm that cysteine-induced sulfide biosynthesis can promote the formation of dissolved and particulate Hg(II)-sulfide species. This report reveals new complexities arising in Hg(II) bioassays with cysteine and emphasizes the need for considering changes in chemical speciation as well as growth stage.

  6. Synthesis of l-cysteine derivatives containing stable sulfur isotopes and application of this synthesis to reactive sulfur metabolome.

    Science.gov (United States)

    Ono, Katsuhiko; Jung, Minkyung; Zhang, Tianli; Tsutsuki, Hiroyasu; Sezaki, Hiroshi; Ihara, Hideshi; Wei, Fan-Yan; Tomizawa, Kazuhito; Akaike, Takaaki; Sawa, Tomohiro

    2017-05-01

    Cysteine persulfide is an L-cysteine derivative having one additional sulfur atom bound to a cysteinyl thiol group, and it serves as a reactive sulfur species that regulates redox homeostasis in cells. Here, we describe a rapid and efficient method of synthesis of L-cysteine derivatives containing isotopic sulfur atoms and application of this method to a reactive sulfur metabolome. We used bacterial cysteine syntheses to incorporate isotopic sulfur atoms into the sulfhydryl moiety of L-cysteine. We cloned three cysteine synthases-CysE, CysK, and CysM-from the Gram-negative bacterium Salmonella enterica serovar Typhimurium LT2, and we generated their recombinant enzymes. We synthesized 34 S-labeled L-cysteine from O-acetyl-L-serine and 34 S-labeled sodium sulfide as substrates for the CysK or CysM reactions. Isotopic labeling of L-cysteine at both sulfur ( 34 S) and nitrogen ( 15 N) atoms was also achieved by performing enzyme reactions with 15 N-labeled L-serine, acetyl-CoA, and 34 S-labeled sodium sulfide in the presence of CysE and CysK. The present enzyme systems can be applied to syntheses of a series of L-cysteine derivatives including L-cystine, L-cystine persulfide, S-sulfo-L-cysteine, L-cysteine sulfonate, and L-selenocystine. We also prepared 34 S-labeled N-acetyl-L-cysteine (NAC) by incubating 34 S-labeled L-cysteine with acetyl coenzyme A in test tubes. Tandem mass spectrometric identification of low-molecular-weight thiols after monobromobimane derivatization revealed the endogenous occurrence of NAC in the cultured mammalian cells such as HeLa cells and J774.1 cells. Furthermore, we successfully demonstrated, by using 34 S-labeled NAC, metabolic conversion of NAC to glutathione and its persulfide, via intermediate formation of L-cysteine, in the cells. The approach using isotopic sulfur labeling combined with mass spectrometry may thus contribute to greater understanding of reactive sulfur metabolome and redox biology. Copyright © 2017 Elsevier Inc

  7. Key Role of Cysteine Residues in Catalysis and Subcellular Localization of Sulfur Oxygenase-Reductase of Acidianus tengchongensis

    DEFF Research Database (Denmark)

    Chen, Z. W.; Jiang, C. Y.; She, Qunxin

    2005-01-01

    ). The thio-modifying reagent N-ethylmaleimide and Zn2+ strongly inhibited the activities of the SORs of A. tengchongensis, suggesting that cysteine residues are important. Site-directed mutagenesis was used to construct four mutant SORs with cysteines replaced by serine or alanine. The purified mutant......Analysis of known sulfur oxygenase-reductases (SORs) and the SOR-like sequences identified from public databases indicated that they all possess three cysteine residues within two conserved motifs (V-G-P-K-V-C31 and C101-X-X-C104; numbering according to the Acidianus tengchongensis numbering system...... proteins were investigated in parallel with the wild-type SOR. Replacement of any cysteine reduced SOR activity by 98.4 to 100%, indicating that all the cysteine residues are crucial to SOR activities. Circular-dichroism and fluorescence spectrum analyses revealed that the wild-type and mutant SORs have...

  8. Lifespan extension and increased resistance to environmental stressors by N-Acetyl-L-Cysteine in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Seung-Il Oh

    2015-05-01

    Full Text Available OBJECTIVE: This study was performed to determine the effect of N-acetyl-L-cysteine, a modified sulfur-containing amino acid that acts as a strong cellular antioxidant, on the response to environmental stressors and on aging in C. elegans. METHOD: The survival of worms under oxidative stress conditions induced by paraquat was evaluated with and without in vivo N-acetyl-L-cysteine treatment. The effect of N-acetyl-L-cysteine on the response to other environmental stressors, including heat stress and ultraviolet irradiation (UV, was also monitored. To investigate the effect on aging, we examined changes in lifespan, fertility, and expression of age-related biomarkers in C. elegans after N-acetyl-L-cysteine treatment. RESULTS: Dietary N-acetyl-L-cysteine supplementation significantly increased resistance to oxidative stress, heat stress, and UV irradiation in C. elegans. In addition, N-acetyl-L-cysteine supplementation significantly extended both the mean and maximum lifespan of C. elegans. The mean lifespan was extended by up to 30.5% with 5 mM N-acetyl-L-cysteine treatment, and the maximum lifespan was increased by 8 days. N-acetyl-L-cysteine supplementation also increased the total number of progeny produced and extended the gravid period of C. elegans. The green fluorescent protein reporter assay revealed that expression of the stress-responsive genes, sod-3 and hsp-16.2, increased significantly following N-acetyl-L-cysteine treatment. CONCLUSION: N-acetyl-L-cysteine supplementation confers a longevity phenotype in C. elegans, possibly through increased resistance to environmental stressors.

  9. Drug susceptibility testing in microaerophilic parasites: Cysteine strongly affects the effectivities of metronidazole and auranofin, a novel and promising antimicrobial

    Directory of Open Access Journals (Sweden)

    David Leitsch

    2017-12-01

    Full Text Available The microaerophilic parasites Entamoeba histolytica, Trichomonas vaginalis, and Giardia lamblia annually cause hundreds of millions of human infections which are treated with antiparasitic drugs. Metronidazole is the most often prescribed drug but also other drugs are in use, and novel drugs with improved characteristics are constantly being developed. One of these novel drugs is auranofin, originally an antirheumatic which has been relabelled for the treatment of parasitic infections. Drug effectivity is arguably the most important criterion for its applicability and is commonly assessed in susceptibility assays using in vitro cultures of a given pathogen. However, drug susceptibility assays can be strongly affected by certain compounds in the growth media. In the case of microaerophilic parasites, cysteine which is added in large amounts as an antioxidant is an obvious candidate because it is highly reactive and known to modulate the toxicity of metronidazole in several microaerophilic parasites.In this study, it was attempted to reduce cysteine concentrations as far as possible without affecting parasite viability by performing drug susceptibility assays under strictly anaerobic conditions in an anaerobic cabinet. Indeed, T. vaginalis and E. histolytica could be grown without any cysteine added and the cysteine concentration necessary to maintain G. lamblia could be reduced to 20%. Susceptibilities to metronidazole were found to be clearly reduced in the presence of cysteine. With auranofin the protective effect of cysteine was extreme, providing protection to concentrations up to 100-fold higher as observed in the absence of cysteine. With three other drugs tested, albendazole, furazolidone and nitazoxanide, all in use against G. lamblia, the effect of cysteine was less pronounced. Oxygen was found to have a less marked impact on metronidazole and auranofin than cysteine but bovine bile which is standardly used in growth media for G

  10. Epstein-Barr virus nuclear antigen 3C stabilizes Gemin3 to block p53-mediated apoptosis.

    Directory of Open Access Journals (Sweden)

    Qiliang Cai

    2011-12-01

    Full Text Available The Epstein-Barr nuclear antigen 3C (EBNA3C, one of the essential latent antigens for Epstein-Barr virus (EBV-induced immortalization of primary human B lymphocytes in vitro, has been implicated in regulating cell proliferation and anti-apoptosis via interaction with several cellular and viral factors. Gemin3 (also named DDX20 or DP103 is a member of DEAD RNA helicase family which exhibits diverse cellular functions including DNA transcription, recombination and repair, and RNA metabolism. Gemin3 was initially identified as a binding partner to EBNA2 and EBNA3C. However, the mechanism by which EBNA3C regulates Gemin3 function remains unclear. Here, we report that EBNA3C directly interacts with Gemin3 through its C-terminal domains. This interaction results in increased stability of Gemin3 and its accumulation in both B lymphoma cells and EBV transformed lymphoblastoid cell lines (LCLs. Moreover, EBNA3C promotes formation of a complex with p53 and Gemin3 which blocks the DNA-binding affinity of p53. Small hairpin RNA based knockdown of Gemin3 in B lymphoma or LCL cells remarkably attenuates the ability of EBNA3C to inhibit the transcription activity of p53 on its downstream genes p21 and Bax, as well as apoptosis. These findings provide the first evidence that Gemin3 may be a common target of oncogenic viruses for driving cell proliferation and anti-apoptotic activities.

  11. Controlling the optical properties of monocrystalline 3C-SiC heteroepitaxially grown on silicon at low temperatures

    Science.gov (United States)

    Colston, Gerard; Myronov, Maksym

    2017-11-01

    Cubic silicon carbide (3C-SiC) offers an alternative wide bandgap semiconductor to conventional materials such as hexagonal silicon carbide (4H-SiC) or gallium nitride (GaN) for the detection of UV light and can offer a closely lattice matched virtual substrate for subsequent GaN heteroepitaxy. As 3C-SiC can be heteroepitaxially grown on silicon (Si) substrates its optical properties can be manipulated by controlling the thickness and doping concentrations. The optical properties of 3C-SiC epilayers have been characterized by measuring the transmission of light through suspended membranes. Decreasing the thickness of the 3C-SiC epilayers is shown to shift the absorbance edge to lower wavelengths, a result of the indirect bandgap nature of silicon carbide. This property, among others, can be exploited to fabricate very low-cost, tuneable 3C-SiC based UV photodetectors. This study investigates the effect of thickness and doping concentration on the optical properties of 3C-SiC epilayers grown at low temperatures by a standard Si based growth process. The results demonstrate the potential photonic applications of 3C-SiC and its heterogeneous integration into the Si industry.

  12. Synthesis and characterization of a cysteine xyloglucan conjugate as mucoadhesive polymer

    Directory of Open Access Journals (Sweden)

    Mangesh Bhalekar

    2013-06-01

    Full Text Available The aim of this study was to improve the mucoadhesive potential of xyloglucan polymer by the covalent attachment of cysteine as thiol moiety. The parent polymer xyloglucan was chemically modified by introducing sulphydryl bearing compound L-cysteine HCl. Different batches of xyloglucan-cysteine conjugates were prepared at varying reaction pH (2-6 and evaluated for optimum thiol incorporation, disulphide group content, swelling behavior, rheological properties and mucoadhesive properties. The obtained conjugates characterized in vitro by quantification of immobilized thiol groups; showed maximum thiol incorporation on xyloglucan (7.67 ± 0.14 % at pH 5. The disulphide group content was found maximum (2.83 ± 0.12 at pH 6. The water uptake at end of 4 h was 5.0 for xyloglucan and was found to decrease in thiolated derivatives with increase in thiolation. Mucoadhesion studies revealed that mucoadhesion of xyloglucan-cysteine conjugate increased more than twice compared to the unmodified polymer. The viscosity of thiomer was more than that of xyloglucan because of formation of disulphide bonds.

  13. Synthesis, characterization, mucoadhesion and biocompatibility of thiolated carboxymethyl dextran-cysteine conjugate.

    Science.gov (United States)

    Shahnaz, G; Perera, G; Sakloetsakun, D; Rahmat, D; Bernkop-Schnürch, A

    2010-05-21

    This study was aimed at improving the mucoadhesive properties of carboxymethyl dextran by the covalent attachment of cysteine. Mediated by a carbodiimide, l-cysteine was covalently attached to the polymer. The resulting CMD-cysteine conjugate (CMD-(273) conjugate) displayed 273+/-20 micromol thiol groups per gram of polymer (mean+/-S.D.; n=3). Within 2h the viscosity of an aqueous mucus/CMD-(273) conjugate mixture pH 7.4 increased at 37 degrees C by more than 85% compared to a mucus/carboxymethyl dextran mixture indicating enlarged interactions between the mucus and the thiolated polymer. Due to the immobilization of cysteine, the swelling velocity of the polymer was significantly accelerated (ppolymer disintegrated within 15 min, whereas tablets of the CMD-(273) conjugate remained stable for 160 min (means+/-S.D.; n=3). Results from LDH and MTT assays on Caco-2 cells revealed 4.96+/-0.98% cytotoxicity and 94.1+/-0.9% cell viability for the CMD-(273) conjugate, respectively. Controlled release of model compound from CMD-(273) conjugate tablets was observed over 6h. These findings suggest that CMD-(273) conjugate is a promising novel polymer for drug delivery systems providing improved mucoadhesive and cohesive properties, greater stability and biocompatibility. Copyright 2010 Elsevier B.V. All rights reserved.

  14. Visible-light-mediated selective arylation of cysteine in batch and flow

    NARCIS (Netherlands)

    Bottecchia, C.; Rubens, M.; Gunnoo, S.B.; Hessel, V.; Madder, A.

    2017-01-01

    A mild visible-light-mediated strategy for cysteine arylation is presented. The method relies on the use of eosin Y as a metal-free photocatalyst and aryldiazonium salts as arylating agents. The reaction can be significantly accelerated in a microflow reactor, whilst allowing the in situ formation

  15. Studies of the structures of rhenium complexes with sulphur-containing amino acids: cysteine and homocysteine

    International Nuclear Information System (INIS)

    Arkowska, A.; Wojciechowski, W.

    1979-01-01

    Two rhenium compounds have been synthesized: compound 1 with cysteine HS-CH 2 -CH-NH 2 -COOH and compound 2 with homocysteine HS-CH 2 -CH 2 -CH-NH 2 -COOH. On the basis of spectroscopic measurements (IR, far IR, Raman, VIS and UV spectra) and magnetic susceptibility measurements their probable electronic and molecular structures have been determined. (author)

  16. Submolecular Electronic Mapping of Single Cysteine Molecules by in Situ Scanning Tunneling Imaging

    DEFF Research Database (Denmark)

    Zhang, Jingdong; Chi, Qijin; Nazmutdinov, R. R.

    2009-01-01

    We have used L-Cysteine (Cys) as a model system to study the surface electronic structures of single molecules at the submolecular level in aqueous buffer solution by a combination of electrochemical scanning tunneling microscopy (in situ STM), electrochemistry including voltammetry and chronocou...

  17. Ultrasonic-assisted synthesis of magnetite based MRI contrast agent using cysteine as the biocapping coating

    International Nuclear Information System (INIS)

    Ahmadi, Reza; Malek, Mahrooz; Hosseini, Hamid Reza Madaah; Shokrgozar, Mohammad Ali; Oghabian, Mohammad Ali; Masoudi, Afshin; Gu Ning; Zhang Yu

    2011-01-01

    Highlights: ► We used cysteine as surfactant to synthesize stable magnetite-based ferrofluids. ► pH increase from 11 to 12 led to particle size decrease from 19.58 to 10.02 nm. ► Cytotoxicity assay showed that synthesized particles were biocompatible. ► MRI results showed that magnetite particles were accumulated in lymph nodes. - Abstract: Magnetite nanoparticles (mean particle size ranging from 10 to 20 nm) were prepared by a biomolecule-assisted solution-phase approach under ultrasonic irradiation. Cysteine was used as the capping agent in the solution. The results show that cysteine could be an efficient biocapping agent in producing Fe 3 O 4 nanoparticles. The crystal structure and magnetic properties of the nanoparticles were characterized by XRD and VSM techniques, respectively. FT-IR was used to investigate the presence of cysteine on the nanoparticles surface. The influence of pH value of the solution on the size distribution and hydrodynamic size of nanoparticles were studied by TEM and DLS methods, respectively. The MTT assay performed by incubation of L929 cells, showed the good biocompability of synthesized ferrofluids. In vitro T1 and T2 relaxivity measurements along with in vivo studies, which were conducted on rats, demonstrate that synthesized nanoparticles are applicable as the contrast agents, especially for imaging of the lymphatic system.

  18. Modulation of Escherichia coli serine acetyltransferase catalytic activity in the cysteine synthase complex

    Czech Academy of Sciences Publication Activity Database

    Benoni, Roberto; De Bei, O.; Paredi, G.; Hayes, C. S.; Franko, N.; Mozzarelli, A.; Bettati, S.; Campanini, B.

    2017-01-01

    Roč. 591, č. 9 (2017), s. 1212-1224 ISSN 0014-5793 Institutional support: RVO:61388963 Keywords : cysteine synthase * protein - protein interaction * serine acetyltransferase Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 3.623, year: 2016

  19. Use of equimolar cysteine/ascorbic acids to recover MCP synthesized Ti(Mg) alloy

    CSIR Research Space (South Africa)

    Mushove, T

    2010-10-01

    Full Text Available Dissolution of waste by-products of mechanochemical processing (MCP) synthesis of Ti(Mg) alloy, from TiO2 and 15 wt.% excess Mg, was conducted in equimolar cysteine/ascorbic acids. The synthesized alloy is inherently mixed with MgO and other oxides...

  20. Mutations at the cysteine codons of the recA gene of Escherichia coli

    International Nuclear Information System (INIS)

    Weisemann, J.M.; Weinstock, G.M.

    1988-01-01

    Each of the three cysteine residues in the Escherichia coli RecA protein was replaced with a number of other amino acids. To do this, each cysteine codon was first converted to a chain-terminating amber codon by oligonucleotide-directed mutagenesis. These amber mutants were then either assayed for function in different suppressor strains or reverted by a second round of mutagenesis with oligonucleotides that had random sequences at the amber codon. Thirty-three different amino acid substitutions were obtained. Mutants were tested for three functions of RecA: survival following UV irradiation, homologous recombination, and induction of the SOS response. It was found that although none of the cysteines is essential for activity, mutations at each of these positions can affect one or more of the activities of RecA, depending on the particular amino acid substitution. In addition, the cysteine at position 116 appears to be involved in the RecA-promoted cleavage of the LexA protein

  1. Effect of free cysteine on the denaturation and aggregation of holo α-lactalbumin

    DEFF Research Database (Denmark)

    Nielsen, Line R.; Lund, Marianne N.; Davies, Michael J.

    2018-01-01

    α-Lactalbumin (α-LA) is a key commercial whey protein for nutritional purposes. The holo protein (calcium saturated) is considered the most heat stable whey protein, capable of refolding from unfolded states under many conditions. This is due to the absence of free thiols (cysteine residues......) that are typically involved in thermal aggregation and thiol–disulphide exchange reactions of other whey proteins. Heating (0–120 min at 90 °C, pH 7.0) holo α-LA generates free thiols through thermal cleavage of disulphide bonds, resulting in aggregates comprising unfolded α-LA species. The addition of free cysteine...... promotes the formation of soluble aggregates, effectively decreasing the holding time required to reach a particular aggregate size in a dose-dependent manner (0.35–1.4 mM cysteine). Excess cysteine (≥14 mM) causes a destabilisation of α-LA, shown by decreased denaturation temperature and gel formation...

  2. Cysteine proteases and wheat (Triticum aestivum L) under drought: A still greatly unexplored association.

    Science.gov (United States)

    Botha, Anna-Maria; Kunert, Karl J; Cullis, Christopher A

    2017-09-01

    Bread wheat (Triticum aestivum L.) provides about 19% of global dietary energy. Environmental stress, such as drought, affects wheat growth causing premature plant senescence and ultimately plant death. A plant response to drought is an increase in protease-mediated proteolysis with rapid degradation of proteins required for metabolic processes. Among the plant proteases that are increased in their activity following stress, cysteine proteases are the best characterized. Very little is known about particular wheat cysteine protease sequences, their expression and also localization. The current knowledge on wheat cysteine proteases belonging to the five clans (CA, CD, CE, CF and CP) is outlined, in particular their expression and possible function under drought. The first successes in establishing an annotated wheat genome database are further highlighted which has allowed more detailed mining of cysteine proteases. We also share our thoughts on future research directions considering the growing availability of genomic resources of this very important food crop. Finally, we also outline future application of developed knowledge in transgenic wheat plants for environmental stress protection and also as senescence markers to monitor wheat growth under environmental stress conditions. © 2017 John Wiley & Sons Ltd.

  3. Formation of elemental sulfur by Chlorella fusca during growth on L-cysteine ethylester

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, F.; Schafer, W.; Schmidt, A.

    1984-01-01

    During growth on L-cysteine ethylester, Chlorella fusca (211-8b) accumulated a substance which contained bound sulfide, which could be liberated by reduction with dithioerythritol (DTE) as inorganic sulfide. This substance was extracted with hot methanol and purified by thin layer chromatography. This substance liberated free sulfide when incubated with mono- and dithiols, and thiocyanate was formed after heating with KCN. The isolated substance cochromatographed with authentic sulfur flower using different solvent systems for thin layer chromatography, high pressure liquid chromatography, and the identical spectrum with a relative ..beta..max at 263 nm was found. The chemical structure was confirmed by mass spectrometry showing a molecular weight of 256 m/e for the S/sub 8/ configuration. No labeled elemental sulfur was detected when the cells were grown on (/sup 35/S)sulfate and L-cysteine ethylester. C. fusca seems to have enzymes for the metabolism of elemental sulfur, since it disappeared after prolonged growth into the stationary phase. Cysteine was formed from O-acetyl-L-serine and elemental sulfur in the presence of thiol groups and purified cysteine synthase from spinach or Chlorella.

  4. Electronic structure of the L-cysteine films on dental alloys studied by ultraviolet photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Ogawa, K; Takahashi, K; Azuma, J; Kamada, M; Tsujibayashi, T; Ichimiya, M

    2013-01-01

    The valence electronic structures of the dental alloys, type 1, type 3, K14, and MC12 and their interaction with L-cysteine have been studied by ultraviolet photoelectron spectroscopy with synchrotron radiation. It was found that the electronic structures of the type-1 and type-3 dental alloys are similar to that of polycrystalline Au, while that of the K14 dental alloy is much affected by Cu. The electronic states of the MC12 dental alloy originate dominantly from Cu 3d states and Pd 4d states around the top of the valence bands, while the 4∼7-eV electronic structure of MC12 originates from the Ag 4d states. The peak shift and the change in shape due to alloying are observed in all the dental alloys. For the L-cysteine thin films, new peak or structure observed around 2 eV on all the dental alloys is suggested to be due to the bonding of S 3sp orbitals with the dental alloy surfaces. The Cu-S bond as well as the Au-S and Au-O bonds may cause the change in the electronic structure of the L-cysteine on type 1, type 3 and K14. For MC12, the interaction with L-cysteine may be dominantly due to the Pd-S, Cu-S, and Ag-O bonds, while the contribution of the Ag-S bond is small.

  5. Synthesis and characterization of arsenic-doped cysteine-capped thoria-based nanoparticles

    International Nuclear Information System (INIS)

    Pereira, F. J.; Díez, M. T.; Aller, A. J.

    2013-01-01

    Thoria materials have been largely used in the nuclear industry. Nonetheless, fluorescent thoria-based nanoparticles provide additional properties to be applied in other fields. Thoria-based nanoparticles, with and without arsenic and cysteine, were prepared in 1,2-ethanediol aqueous solutions by a simple precipitation procedure. The synthesized thoria-based nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (ED-XRS), Raman spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and fluorescence microscopy. The presence of arsenic and cysteine, as well as the use of a thermal treatment facilitated fluorescence emission of the thoria-based nanoparticles. Arsenic-doped and cysteine-capped thoria-based nanoparticles prepared in 2.5 M 1,2-ethanediol solutions and treated at 348 K showed small crystallite sizes and strong fluorescence. However, thoria nanoparticles subjected to a thermal treatment at 873 K also produced strong fluorescence with a very narrow size distribution and much smaller crystallite sizes, 5 nm being the average size as shown by XRD and TEM. The XRD data indicated that, even after doping of arsenic in the crystal lattice of ThO 2 , the samples treated at 873 K were phase pure with the fluorite cubic structure. The Raman and FT-IR spectra shown the most characteristics vibrational peaks of cysteine together with other peaks related to the bonds of this molecule to thoria and arsenic when present

  6. Indirect flow injection determination of N-acetyl-L-cysteine using cerium(IV) and ferroin

    International Nuclear Information System (INIS)

    Vieira, Heberth Juliano; Fatibello-Filho, Orlando

    2005-01-01

    An indirect flow injection spectrophotometric procedure is proposed for the determination of N-acetyl-L-cysteine in pharmaceutical formulations. In this system, ferroin ([Fe(II)-(fen) 2 ] 2+ ) in excess, with a strong absorption at 500 nm, is oxidized by cerium(IV) yielding cerium(III) and [Fe(III)-(fen) 2 ] 3+ (colorless), thus producing a baseline. When N-acetyl-L-cysteine solution is introduced into the flow injection system, it reacts with cerium(IV) increasing the analytical signal in proportion to the drug concentration. Under optimal experimental conditions, the linearity of the analytical curve for N-acetyl-L-cysteine ranged from 6.5x10 -6 to 1.3x10 -4 mol L -1 . The detection limit was 5.0x10 -6 mol L -1 and recoveries between 98.0 and 106% were obtained. The sampling frequency was 60 determinations per hour and the RSD was smaller than 1.4% for 2.2x10 -5 mol L -1 N-acetyl-L-cysteine. (author)

  7. Electrochemical immobilization of biomolecules on gold surface modified with monolayered L-cysteine

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Mitsunori, E-mail: honda.mitsunori@jaea.go.jp; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie

    2014-04-01

    Immobilization of organic molecules on the top of a metal surface is not easy because of lattice mismatch between organic and metal crystals. Gold atoms bind to thiol groups through strong chemical bonds, and a self-assembled monolayer of sulfur-terminated organic molecules is formed on the gold surface. Herein, we suggested that a monolayer of L-cysteine deposited on a gold surface can act as a buffer layer to immobilize biomolecules on the metal surface. We selected lactic acid as the immobilized biomolecule because it is one of the simplest carboxyl-containing biomolecules. The immobilization of lactic acid on the metal surface was carried out by an electrochemical method in an aqueous environment under the potential range varying from − 0.6 to + 0.8 V. The surface chemical states before and after the electrochemical reaction were characterized using X-ray photoelectron spectroscopy (XPS). The N 1s and C 1s XPS spectra showed that the L-cysteine-modified gold surface can immobilize lactic acid via peptide bonds. This technique might enable the immobilization of large organic molecules and biomolecules. - Highlights: • Monolayer l-cysteine deposited on Au surface as a buffer layer to immobilize biomolecules. • Lactic acid as the immobilized biomolecule as it is simple carboxyl-containing biomolecule. • X-ray photoelectron spectroscopy (XPS) of surface chemical states, before and after. • L-cysteine-modified Au surface can immobilize lactic acid via peptide bonds.

  8. Electrochemical immobilization of biomolecules on gold surface modified with monolayered L-cysteine

    International Nuclear Information System (INIS)

    Honda, Mitsunori; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie

    2014-01-01

    Immobilization of organic molecules on the top of a metal surface is not easy because of lattice mismatch between organic and metal crystals. Gold atoms bind to thiol groups through strong chemical bonds, and a self-assembled monolayer of sulfur-terminated organic molecules is formed on the gold surface. Herein, we suggested that a monolayer of L-cysteine deposited on a gold surface can act as a buffer layer to immobilize biomolecules on the metal surface. We selected lactic acid as the immobilized biomolecule because it is one of the simplest carboxyl-containing biomolecules. The immobilization of lactic acid on the metal surface was carried out by an electrochemical method in an aqueous environment under the potential range varying from − 0.6 to + 0.8 V. The surface chemical states before and after the electrochemical reaction were characterized using X-ray photoelectron spectroscopy (XPS). The N 1s and C 1s XPS spectra showed that the L-cysteine-modified gold surface can immobilize lactic acid via peptide bonds. This technique might enable the immobilization of large organic molecules and biomolecules. - Highlights: • Monolayer l-cysteine deposited on Au surface as a buffer layer to immobilize biomolecules. • Lactic acid as the immobilized biomolecule as it is simple carboxyl-containing biomolecule. • X-ray photoelectron spectroscopy (XPS) of surface chemical states, before and after. • L-cysteine-modified Au surface can immobilize lactic acid via peptide bonds

  9. Urinary excretion of N-acetyl-S-allyl-L-cystein upon garlic consumption by human volunteers.

    NARCIS (Netherlands)

    de Rooij, B.M.; Boogaard, P.J.; Rijksen, D.A.; Commandeur, J.N.M.; Vermeulen, N.P.E.

    1996-01-01

    N-Acetyl-S-allyl-L-cysteine (allylmercapturic acid, ALMA) was previously detected in urine from humans consuming garlic. Exposure of rats to allyl halides is also known to lead to excretion of ALMA in urine. ALMA is a potential biomarker for exposure assessment of workers exposed to allyl halides.

  10. Micronutrients, N-Acetyl Cysteine, Probiotics and Prebiotics, A Review of Effectiveness in Reducing HIV Progression

    NARCIS (Netherlands)

    R.B.S. Hummelen (Ruben); J. Hemsworth (Jaimie); G.K. Reid (Gregor)

    2010-01-01

    textabstractLow serum concentrations of micronutrients, intestinal abnormalities, and an inflammatory state have been associated with HIV progression. These may be ameliorated by micronutrients, N-acetyl cysteine, probiotics, and prebiotics. This review aims to integrate the evidence from clinical

  11. Evaluation of cysteine ethyl ester as efficient inducer for glutathione overproduction in Saccharomyces spp.

    Science.gov (United States)

    Lorenz, Eric; Schmacht, Maximilian; Senz, Martin

    2016-11-01

    Economical yeast based glutathione (GSH) production is a process that is influenced by several factors like raw material and production costs, biomass production and efficient biotransformation of adequate precursors into the final product GSH. Nowadays the usage of cysteine for the microbial conversion into GSH is industrial state of practice. In the following study, the potential of different inducers to increase the GSH content was evaluated by means of design of experiments methodology. Investigations were executed in three natural Saccharomyces strains, S. cerevisiae, S. bayanus and S. boulardii, in a well suited 50ml shake tube system. Results of shake tube experiments were confirmed in traditional baffled shake flasks and finally via batch cultivation in lab-scale bioreactors under controlled conditions. Comprehensive studies showed that the usage of cysteine ethyl ester (CEE) for the batch-wise biotransformation into GSH led up to a more than 2.2 times higher yield compared to cysteine as inducer. Additionally, the intracellular GSH content could be significantly increased for all strains in terms of 2.29±0.29% for cysteine to 3.65±0.23% for CEE, respectively, in bioreactors. Thus, the usage of CEE provides a highly attractive inducing strategy for the GSH overproduction. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Glutathione provides a source of cysteine essential for intracellular multiplication of Francisella tularensis.

    Directory of Open Access Journals (Sweden)

    Khaled Alkhuder

    2009-01-01

    Full Text Available Francisella tularensis is a highly infectious bacterium causing the zoonotic disease tularemia. Its ability to multiply and survive in macrophages is critical for its virulence. By screening a bank of HimarFT transposon mutants of the F. tularensis live vaccine strain (LVS to isolate intracellular growth-deficient mutants, we selected one mutant in a gene encoding a putative gamma-glutamyl transpeptidase (GGT. This gene (FTL_0766 was hence designated ggt. The mutant strain showed impaired intracellular multiplication and was strongly attenuated for virulence in mice. Here we present evidence that the GGT activity of F. tularensis allows utilization of glutathione (GSH, gamma-glutamyl-cysteinyl-glycine and gamma-glutamyl-cysteine dipeptide as cysteine sources to ensure intracellular growth. This is the first demonstration of the essential role of a nutrient acquisition system in the intracellular multiplication of F. tularensis. GSH is the most abundant source of cysteine in the host cytosol. Thus, the capacity this intracellular bacterial pathogen has evolved to utilize the available GSH, as a source of cysteine in the host cytosol, constitutes a paradigm of bacteria-host adaptation.

  13. Irreversible Cysteine-Selective Protein Labeling Employing Modular Electrophilic Tetrafluoroethylation Reagents

    Czech Academy of Sciences Publication Activity Database

    Václavík, Jiří; Zschoche, R.; Klimánková, Iveta; Matoušek, V.; Beier, Petr; Hilvert, D.; Togni, A.

    2017-01-01

    Roč. 23, č. 27 (2017), s. 6490-6494 ISSN 0947-6539 R&D Projects: GA ČR(CZ) GA17-00598S Institutional support: RVO:61388963 Keywords : bioconjugation * cysteine * enzymes * fluorine * fluoroalkylation * hypervalent iodine Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 5.317, year: 2016

  14. Covalent binding of nitrogen mustards to the cysteine-34 residue in human serum albumin

    NARCIS (Netherlands)

    Noort, D.; Hulst, A.G.; Jansen, R.

    2002-01-01

    Covalent binding of various clinically important nitrogen mustards to the cysteine-34 residue of human serum albumin, in vitro and in vivo, is demonstrated. A rapid method for detection of these adducts is presented, based on liquid chromatography-tandem mass spectrometry analysis of the adducted

  15. Role of conserved cysteine residues in Herbaspirillum seropedicae NifA activity.

    Science.gov (United States)

    Oliveira, Marco A S; Baura, Valter A; Aquino, Bruno; Huergo, Luciano F; Kadowaki, Marco A S; Chubatsu, Leda S; Souza, Emanuel M; Dixon, Ray; Pedrosa, Fábio O; Wassem, Roseli; Monteiro, Rose A

    2009-01-01

    Herbaspirillum seropedicae is an endophytic diazotrophic bacterium that associates with economically important crops. NifA protein, the transcriptional activator of nif genes in H. seropedicae, binds to nif promoters and, together with RNA polymerase-sigma(54) holoenzyme, catalyzes the formation of open complexes to allow transcription initiation. The activity of H. seropedicae NifA is controlled by ammonium and oxygen levels, but the mechanisms of such control are unknown. Oxygen sensitivity is attributed to a conserved motif of cysteine residues in NifA that spans the central AAA+ domain and the interdomain linker that connects the AAA+ domain to the C-terminal DNA binding domain. Here we mutagenized this conserved motif of cysteines and assayed the activity of mutant proteins in vivo. We also purified the mutant variants of NifA and tested their capacity to bind to the nifB promoter region. Chimeric proteins between H. seropedicae NifA, an oxygen-sensitive protein, and Azotobacter vinelandii NifA, an oxygen-tolerant protein, were constructed and showed that the oxygen response is conferred by the central AAA+ and C-terminal DNA binding domains of H. seropedicae NifA. We conclude that the conserved cysteine motif is essential for NifA activity, although single cysteine-to-serine mutants are still competent at binding DNA.

  16. Micronutrients, N-acetyl cysteine, probiotics and prebiotics, a review of effectiveness in reducing HIV progression

    NARCIS (Netherlands)

    R.B.S. Hummelen (Ruben); J. Hemsworth (Jaimie); G. Reid (Gregor)

    2010-01-01

    textabstractLow serum concentrations of micronutrients, intestinal abnormalities, and an inflammatory state have been associated with HIV progression. These may be ameliorated by micronutrients, N-acetyl cysteine, probiotics, and prebiotics. This review aims to integrate the evidence from clinical

  17. Effects of N-acetyl cysteine on lipid levels and on leukocyte and ...

    African Journals Online (AJOL)

    Introduction: Many of studies have shown that increased lipid levels play a significant role in the pathogenesis of atherosclerosis after splenectomy. We investigated the effects of N-acetyl cysteine (NAC) on lipid parameters and leukocyte and platelet (PLT) levels following splenectomy. Materials and Methods: 32 Sprague.

  18. Cyst(e)ine requirements in enterally fed very low birth weight preterm infants.

    Science.gov (United States)

    Riedijk, Maaike A; Voortman, Gardi; van Beek, Ron H T; Baartmans, Martin G A; Wafelman, Leontien S; van Goudoever, Johannes B

    2008-03-01

    Optimal nutrition is of utmost importance for the preterm infant's later health and developmental outcome. Amino acid requirements for preterm infants differ from those for term and older infants, because growth rates differ. Some nonessential amino acids, however, cannot be sufficiently synthesized endogenously. Cyst(e)ine is supposed to be such a conditionally essential amino acid in preterm infants. The objective of this study was to determine, at 32 and 35 weeks' postmenstrual age, cyst(e)ine requirements in fully enterally fed very low birth weight preterm infants with gestational ages of ine requirement was determined with the indicator amino acid oxidation technique ([1-(13)C]phenylalanine) after 24-hour adaptation. Fractional [1-(13)C]phenylalanine oxidation was established in 47 very low birth weight preterm infants (mean gestational age: 28 weeks +/- 1 week SD; birth weight: 1.07 kg +/- 0.21 kg SD). Increase in dietary cyst(e)ine intake did not result in a decrease in fractional [1-(13)C]phenylalanine oxidation. These data do not support the hypothesis that endogenous cyst(e)ine synthesis is limited in very low birth weight preterm infants with gestational ages of ine requirement is ine is probably not a conditionally essential amino acid in these infants.

  19. The effect of N-acetyl-L-cysteine on the viscosity of ileal neobladder mucus.

    NARCIS (Netherlands)

    Schrier, B.P.; Lichtendonk, W.J.; Witjes, J.A.

    2002-01-01

    N-acetyl-L-cysteine (NAC) proved to be an effective mucolytic in pulmonary secretions. Our goal was to investigate the in vitro effect of NAC on viscosity of ileal neobladder mucus. The urine of a patient with an ileal neobladder was collected during the first 7 days postoperatively and stored in a

  20. Cathodic Stripping Voltammetry of Cysteine Using Silver and Copper Solid Amalgam Electrodes

    Czech Academy of Sciences Publication Activity Database

    Josypčuk, Bohdan; Novotný, Ladislav

    2002-01-01

    Roč. 56, č. 5 (2002), s. 971-976 ISSN 0039-9140 R&D Projects: GA ČR GV204/97/K084 Institutional research plan: CEZ:AV0Z4040901 Keywords : silver or copper solid amalgam electrode * cysteine * voltammetry Subject RIV: CG - Electrochemistry Impact factor: 2.054, year: 2002

  1. Effect of cysteine and cystine addition on sensory profile and potent odorants of extruded potato snacks.

    Science.gov (United States)

    Majcher, Małgorzata A; Jeleń, Henryk H

    2007-07-11

    Aromas generated in extruded potato snacks without and with addition of 0.25, 0.5, and 1% (w/w) of flavor precursors, cysteine and cystine, were compared and evaluated by descriptive sensory profiling. The results showed that high addition of cysteine (0.5 and 1%) resulted in the formation of undesirable odor and taste described as mercaptanic/sulfur, onion-like, and bitter; on the contrary, addition of cystine even at high concentration gave product with pleasant odor and taste, slightly changed into breadlike notes. GC/O analysis showed cysteine to be a much more reactive flavor precursor than cystine, stimulating formation of 12 compounds with garlic, sulfury, burnt, pungent/beer, cabbage/mold, meatlike, roasted, and popcorn odor notes. Further analysis performed by the AEDA technique identified 2-methyl-3-furanthiol (FD 2048) as a most potent odorant of extruded potato snacks with 1% addition of cysteine. Other identified compounds with high FD were butanal, 3-methyl-2-butenethiol, 2-methylthiazole, methional, 2-acetyl-1-pyrroline, and 3-hydroxy-4,5-dimethyl-2(5H)-furanone. In the case of cystine addition (1%) the highest FD factors were calculated for butanal, 2-acetyl-1-pyrroline, benzenemethanethiol, methional, phenylacetaldehyde, dimethyltrisulfide, 1-octen-3-ol, 1,5-octadien-3-one, and 2-acetylpyrazine.

  2. CHANDRA OBSERVATIONS OF 3C RADIO SOURCES WITH z < 0.3. II. COMPLETING THE SNAPSHOT SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Massaro, F. [SLAC National Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Tremblay, G. R. [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei Muenchen (Germany); Harris, D. E.; O' Dea, C. P. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Kharb, P.; Axon, D. [Department of Physics, Rochester Institute of Technology, Carlson Center for Imaging Science 76-3144, 84 Lomb Memorial Dr., Rochester, NY 14623 (United States); Balmaverde, B.; Capetti, A. [INAF-Osservatorio Astrofisico di Torino, Strada Osservatorio 20, I-10025 Pino Torinese (Italy); Baum, S. A. [Carlson Center for Imaging Science 76-3144, 84 Lomb Memorial Dr., Rochester, NY 14623 (United States); Chiaberge, M.; Macchetto, F. D.; Sparks, W. [Space Telescope Science Institute, 3700 San Martine Drive, Baltimore, MD 21218 (United States); Gilli, R. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Giovannini, G. [INAF-Istituto di Radioastronomia di Bologna, Via Gobetti 101, I-40129 Bologna (Italy); Grandi, P.; Torresi, E. [INAF-IASF-Istituto di Astrofisica Spaziale e fisica Cosmica di Bologna, Via P. Gobetti 101, I-40129 Bologna (Italy); Risaliti, G. [INAF-Osservatorio Astronomico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy)

    2012-12-15

    We report on the second round of Chandra observations of the 3C snapshot survey developed to observe the complete sample of 3C radio sources with z < 0.3 for 8 ks each. In the first paper, we illustrated the basic data reduction and analysis procedures performed for the 30 sources of the 3C sample observed during Chandra Cycle 9, while here we present the data for the remaining 27 sources observed during Cycle 12. We measured the X-ray intensity of the nuclei and of any radio hot spots and jet features with associated X-ray emission. X-ray fluxes in three energy bands, i.e., soft, medium, and hard, for all the sources analyzed are also reported. For the stronger nuclei, we also applied the standard spectral analysis, which provides the best-fit values of the X-ray spectral index and absorbing column density. In addition, a detailed analysis of bright X-ray nuclei that could be affected by pile-up has been performed. X-ray emission was detected for all the nuclei of the radio sources in our sample except for 3C 319. Among the current sample, there are two compact steep spectrum radio sources, two broad-line radio galaxies, and one wide angle tail radio galaxy, 3C 89, hosted in a cluster of galaxies clearly visible in our Chandra snapshot observation. In addition, we also detected soft X-ray emission arising from the galaxy cluster surrounding 3C 196.1. Finally, X-ray emission from hot spots has been found in three FR II radio sources and, in the case of 3C 459, we also report the detection of X-ray emission associated with the eastern radio lobe as well as X-ray emission cospatial with radio jets in 3C 29 and 3C 402.

  3. Cyst(e)ine imbalance and its effect on methionine precursor utilization in chicks.

    Science.gov (United States)

    Dilger, R N; Baker, D H

    2008-08-01

    Five 9- or 12-d chick growth bioassays were done in batteries using 2 Met-deficient diets: a purified AA-based diet containing (by analysis, as-fed) 20.3% CP, 0.12% Met, and 0.05% cyst(e)ine; and an AA-fortified corn-peanut meal diet containing (by analysis, as-fed) 19.0% CP, 0.22% Met, and 0.23% cyst(e) ine. Feed-grade DL-Met (dl-M; 99%) was compared with feed-grade DL-OH-Met, Ca (OH-M; 84%). When the purified diet was modified to contain 0.12% Met and 0.20% or greater cyst(e)ine, slope-ratio assays involving graded dosing of DL-M (0, 404, 808, and 1,212 mg of DL-M/kg) or isosulfurous levels of OH-M resulted in linear (P ine [i.e., 0.12% Met, 0.12% cyst(e)ine]. When this diet was supplemented with either 404 mg of DL-M/kg or 476 mg of OH-M/kg, BW gain and G:F responded (P 0.10). Assays 4 and 5 used the corn-peanut meal basal diet containing 0.22% total Met and 0.23% total cyst(e)ine. In both assays, addition of either 465 mg of DL-M/kg or 554 mg of OH-M/kg resulted in increased (P ine concentration. In the absence of excess cyst(e)ine, BW gain responses to DL-M and OH-M were similar, but when 0.10% excess cyst(e)ine was provided as L-cystine or feather meal, DL-M responses tended to exceed those of OH-M. Moreover, this small excess of dietary cyst(e)ine, regardless of source, depressed (P ine, when included in Met-deficient diets, has the potential to be both anorexigenic and pernicious to OH-M utilization.

  4. Direct insight into grains formation in Si layers grown on 3C-SiC by chemical vapor deposition

    International Nuclear Information System (INIS)

    Khazaka, Rami; Portail, Marc; Vennéguès, Philippe; Alquier, Daniel; Michaud, Jean François

    2015-01-01

    Graphical abstract: In this contribution, we demonstrated the influence of the 3C-SiC layer on the subsequent growth of Si epilayers. We were able to give a direct evidence that the rotation in the Si epilayer of 90° around the growth direction occurs exactly on the termination of an antiphase boundary in the 3C-SiC layer as shown in the figure above. Thus, increasing the layer thickness of the 3C-SiC leads to a direct improvement of the crystalline quality of the subsequent Si epilayer. (a) Cross-section bright-field TEM image of the Si/3C-SiC layer stack along two 3C-SiC zone axes [1 −1 0] and [1 1 0] (equivalent to [1 −1 1] and [1 1 2] in Si, respectively), (b) dark field image selecting a (2 0 −2) electron diffraction spot indicated by the black circle in the SAED shown as inset, (c) dark field image selecting a (−1 1 −1) electron diffraction spot indicated by the black circle in the SAED shown as inset. The dotted white line in the images show the position of the defect in the 3C-SiC layer. - Abstract: This work presents a structural study of silicon (Si) thin films grown on cubic silicon carbide (3C-SiC) by chemical vapor deposition. The presence of grains rotated by 90° around the growth direction in the Si layer is directly related to the presence of antiphase domains on the 3C-SiC surface. We were able to provide a direct evidence that the 90° rotation of Si grains around the growth direction occurs exactly on the termination of antiphase boundaries (APBs) in 3C-SiC layer. Increasing the 3C-SiC thickness reduces the APBs density on 3C-SiC surface leading to a clear improvement of the uppermost Si film crystal quality. Furthermore, we observed by high resolution plan-view TEM images the presence of hexagonal Si domains limited to few nm in size. These hexagonal Si domains are inclusions in small Si grains enclosed in larger ones rotated by 90°. Finally, we propose a model of grains formation in the Si layer taking into consideration the effect

  5. Suzaku Diagnostics of the Energetics in the Lobes of the Giant Radio Galaxy 3C 35

    Science.gov (United States)

    Isobe, Naoki; Seta, Hiromi; Gandhi, Poshak; Tashiro, Makoto S.

    2011-02-01

    The Suzaku observation of a giant radio galaxy 3C 35 revealed faint extended X-ray emission, associated with its radio lobes and/or host galaxy. After careful subtraction of the X-ray and non-X-ray background and contaminating X-ray sources, the X-ray spectrum of the faint emission was reproduced by a sum of the power-law (PL) and soft thermal components. The soft component was attributed to the thermal plasma emission from the host galaxy. The photon index of the PL component, Γ = 1.35+0.56 -0.86 +0.11 -0.10, where the first and second errors represent the statistical and systematic ones, was found to agree with the synchrotron radio index from the lobes, ΓR = 1.7. Thus, the PL component was attributed to the inverse Compton (IC) X-rays from the synchrotron electrons in the lobes. The X-ray flux density at 1 keV was derived as 13.6 ± 5.4+4.0 -3.6 nJy with the photon index fixed at the radio value. The X-ray surface brightness from these lobes (~0.2 nJy arcmin-2) is lowest among the lobes studied through the IC X-ray emission. In combination with the synchrotron radio flux density, 7.5 ± 0.2 Jy at 327.4 MHz, the electron energy density spatially averaged over the lobes was evaluated to be the lowest among those radio galaxies, as u e = (5.8 ± 2.3+1.9 -1.7) × 10-14 erg cm-3 over the electron Lorentz factor of 103-105. The magnetic energy density was calculated as u m = (3.1+2.5 -1.0 +1.4 -0.9) × 10-14 erg cm-3, corresponding to the magnetic field strength of 0.88+0.31 -0.16 +0.19 -0.14 μG. These results suggest that the energetics in the 3C 35 lobes are nearly consistent with equipartition between the electrons and magnetic fields.

  6. The WEBT Campaign on the Blazar 3C 279 in 2006

    Science.gov (United States)

    Böttcher, M.; Basu, S.; Joshi, M.; Villata, M.; Arai, A.; Aryan, N.; Asfandiyarov, I. M.; Bach, U.; Bachev, R.; Berduygin, A.; Blaek, M.; Buemi, C.; Castro-Tirado, A. J.; De Ugarte Postigo, A.; Frasca, A.; Fuhrmann, L.; Hagen-Thorn, V. A.; Henson, G.; Hovatta, T.; Hudec, R.; Ibrahimov, M.; Ishii, Y.; Ivanidze, R.; Jelínek, M.; Kamada, M.; Kapanadze, B.; Katsuura, M.; Kotaka, D.; Kovalev, Y. Y.; Kovalev, Yu. A.; Kubánek, P.; Kurosaki, M.; Kurtanidze, O.; Lähteenmäki, A.; Lanteri, L.; Larionov, V. M.; Larionova, L.; Lee, C.-U.; Leto, P.; Lindfors, E.; Marilli, E.; Marshall, K.; Miller, H. R.; Mingaliev, M. G.; Mirabal, N.; Mizoguchi, S.; Nakamura, K.; Nieppola, E.; Nikolashvili, M.; Nilsson, K.; Nishiyama, S.; Ohlert, J.; Osterman, M. A.; Pak, S.; Pasanen, M.; Peters, C. S.; Pursimo, T.; Raiteri, C. M.; Robertson, J.; Robertson, T.; Ryle, W. T.; Sadakane, K.; Sadun, A.; Sigua, L.; Sohn, B.-W.; Strigachev, A.; Sumitomo, N.; Takalo, L. O.; Tamesue, Y.; Tanaka, K.; Thorstensen, J. R.; Tosti, G.; Trigilio, C.; Umana, G.; Vennes, S.; Vitek, S.; Volvach, A.; Webb, J.; Yamanaka, M.; Yim, H.-S.

    2007-12-01

    The quasar 3C 279 was the target of an extensive multiwavelength monitoring campaign from 2006 January through April. An optical-IR-radio monitoring campaign by the Whole Earth Blazar Telescope (WEBT) collaboration was organized around target-of-opportunity X-ray and soft γ-ray observations with Chandra and INTEGRAL in 2006 mid-January, with additional X-ray coverage by RXTE and Swift XRT. In this paper we focus on the results of the WEBT campaign. The source exhibited substantial variability of optical flux and spectral shape, with a characteristic timescale of a few days. The variability patterns throughout the optical BVRI bands were very closely correlated with each other, while there was no obvious correlation between the optical and radio variability. After the ToO trigger, the optical flux underwent a remarkably clean quasi-exponential decay by about 1 mag, with a decay timescale of τd~12.8 days. In intriguing contrast to other (in particular, BL Lac type) blazars, we find a lag of shorter wavelength behind longer wavelength variability throughout the RVB wavelength ranges, with a time delay increasing with increasing frequency. Spectral hardening during flares appears delayed with respect to a rising optical flux. This, in combination with the very steep IR-optical continuum spectral index of α0~1.5-2.0, may indicate a highly oblique magnetic field configuration near the base of the jet, leading to inefficient particle acceleration and a very steep electron injection spectrum. An alternative explanation through a slow (timescale of several days) acceleration mechanism would require an unusually low magnetic field of B<~0.2 G, about an order of magnitude lower than inferred from previous analyses of simultaneous SEDs of 3C 279 and other flat-spectrum radio quasars with similar properties. For questions regarding the availability of the data from the WEBT campaign presented in this paper, please contact the WEBT President Massimo Villata at villata@oato.inaf.it.

  7. STAR-JET INTERACTIONS AND GAMMA-RAY OUTBURSTS FROM 3C454.3

    Energy Technology Data Exchange (ETDEWEB)

    Khangulyan, D. V. [Institute of Space and Astronautical Science/JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Barkov, M. V. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Bosch-Ramon, V. [Departament d' Astronomia i Meteorologia, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Marti i Franques 1, E-08028 Barcelona (Spain); Aharonian, F. A. [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland); Dorodnitsyn, A. V. [Laboratory for High Energy Astrophysics, NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

    2013-09-10

    We propose a model to explain the ultra-bright GeV gamma-ray flares observed from the blazar 3C454.3. The model is based on the concept of a relativistic jet interacting with compact gas condensations produced when a star (a red giant) crosses the jet close to the central black hole. The study includes an analytical treatment of the evolution of the envelope lost by the star within the jet, and calculations of the related high-energy radiation. The model readily explains the day-long that varies on timescales of hours, GeV gamma-ray flare from 3C454.3, observed during 2010 November on top of a plateau lasting weeks. In the proposed scenario, the plateau state is caused by a strong wind generated by the heating of the stellar atmosphere due to nonthermal particles accelerated at the jet-star interaction region. The flare itself could be produced by a few clouds of matter lost by the red giant after the initial impact of the jet. In the framework of the proposed scenario, the observations constrain the key model parameters of the source, including the mass of the central black hole: M{sub BH} {approx_equal} 10{sup 9} M{sub Sun }, the total jet power: L{sub j} {approx_equal} 10{sup 48} erg s{sup -1}, and the Doppler factor of the gamma-ray emitting clouds: {delta} {approx_equal} 20. Whereas we do not specify the particle acceleration mechanisms, the potential gamma-ray production processes are discussed and compared in the context of the proposed model. We argue that synchrotron radiation of protons has certain advantages compared to other radiation channels of directlyaccelerated electrons. An injected proton distribution {proportional_to}E {sup -1} or harder below the relevant energies would be favored to alleviate the tight energetic constraints and to avoid the violation of the observational low-energy constraints.

  8. 3C 220.3: A radio galaxy lensing a submillimeter galaxy

    Energy Technology Data Exchange (ETDEWEB)

    Haas, Martin; Westhues, Christian; Chini, Rolf [Astronomisches Institut, Ruhr Universität, Bochum (Germany); Leipski, Christian; Klaas, Ulrich; Meisenheimer, Klaus [Max-Planck-Institut für Astronomie, Heidelberg (Germany); Barthel, Peter; Koopmans, Léon V. E. [Kapteyn Astronomical Institute, University of Groningen (Netherlands); Wilkes, Belinda J.; Bussmann, R. Shane; Willner, S. P.; Ashby, Matthew L. N.; Kuraszkiewicz, Joanna [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Vegetti, Simona [Max-Planck-Institut für Astrophysik, Garching (Germany); Clements, David L. [Imperial College, London (United Kingdom); Fassnacht, Christopher D. [University of California, Davis, CA (United States); Horesh, Assaf [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA (United States); Lagattuta, David J. [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn (Australia); Stern, Daniel; Wylezalek, Dominika, E-mail: haas@astro.rub.de [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA (United States)

    2014-07-20

    Herschel Space Observatory photometry and extensive multiwavelength follow-up have revealed that the powerful radio galaxy (PRG) 3C 220.3 at z = 0.685 acts as a gravitational lens for a background submillimeter galaxy (SMG) at z = 2.221. At an observed wavelength of 1 mm, the SMG is lensed into three distinct images. In the observed near infrared, these images are connected by an arc of ∼1''.8 radius forming an Einstein half-ring centered near the radio galaxy. In visible light, only the arc is apparent. 3C 220.3 is the only known instance of strong galaxy-scale lensing by a PRG not located in a galaxy cluster and therefore it offers the potential to probe the dark matter content of the radio galaxy host. Lens modeling rejects a single lens, but two lenses centered on the radio galaxy host A and a companion B, separated by 1''.5, provide a fit consistent with all data and reveal faint candidates for the predicted fourth and fifth images. The model does not require an extended common dark matter halo, consistent with the absence of extended bright X-ray emission on our Chandra image. The projected dark matter fractions within the Einstein radii of A (1''.02) and B (0''.61) are about 0.4 ± 0.3 and 0.55 ± 0.3. The mass to i-band light ratios of A and B, M/L{sub i}∼8±4 M{sub ⊙} L{sub ⊙}{sup −1}, appear comparable to those of radio-quiet lensing galaxies at the same redshift in the CfA-Arizona Space Telescope LEns Survey, Lenses Structure and Dynamics, and Strong Lenses in the Legacy Survey samples. The lensed SMG is extremely bright with observed f(250 μm) = 440 mJy owing to a magnification factor μ ∼ 10. The SMG spectrum shows luminous, narrow C IV λ1549 Å emission, revealing that the SMG houses a hidden quasar in addition to a violent starburst. Multicolor image reconstruction of the SMG indicates a bipolar morphology of the emitted ultraviolet (UV) light suggestive of cones through which UV light escapes a

  9. Effects of low atmospheric CO2 and elevated temperature during growth on the gas exchange responses of C3, C3-C4 intermediate, and C4 species from three evolutionary lineages of C4 photosynthesis.

    Science.gov (United States)

    Vogan, Patrick J; Sage, Rowan F

    2012-06-01

    This study evaluates acclimation of photosynthesis and stomatal conductance in three evolutionary lineages of C(3), C(3)-C(4) intermediate, and C(4) species grown in the low CO(2) and hot conditions proposed to favo r the evolution of C(4) photosynthesis. Closely related C(3), C(3)-C(4), and C(4) species in the genera Flaveria, Heliotropium, and Alternanthera were grown near 380 and 180 μmol CO(2) mol(-1) air and day/night temperatures of 37/29°C. Growth CO(2) had no effect on photosynthetic capacity or nitrogen allocation to Rubisco and electron transport in any of the species. There was also no effect of growth CO(2) on photosynthetic and stomatal responses to intercellular CO(2) concentration. These results demonstrate little ability to acclimate to low CO(2) growth conditions in closely related C(3) and C(3)-C(4) species, indicating that, during past episodes of low CO(2), individual C(3) plants had little ability to adjust their photosynthetic physiology to compensate for carbon starvation. This deficiency could have favored selection for more efficient modes of carbon assimilation, such as C(3)-C(4) intermediacy. The C(3)-C(4) species had approximately 50% greater rates of net CO(2) assimilation than the C(3) species when measured at the growth conditions of 180 μmol mol(-1) and 37°C, demonstrating the superiority of the C(3)-C(4) pathway in low atmospheric CO(2) and hot climates of recent geological time.

  10. Selective electrochemical determination of homocysteine in the presence of cysteine and glutathione

    International Nuclear Information System (INIS)

    Salehzadeh, Hamid; Mokhtari, Banafsheh; Nematollahi, Davood

    2014-01-01

    Graphical abstract: 3,5-Di-tert-buthylcatechol was used for the selective electrochemical determination of homocysteine in the presence of cysteine and glutathione at the glassy carbon and carbon nanotube modified glassy carbon electrode. - Highlights: • Selective electrochemical determination of homocysteine. • Catalytic electron transfer of 3,5-di-tert-buthylcatechol in the presence of homocysteine. • Michael type addition reaction of electrochemically generated 3,5-di-tert-buthyl-o-benzoquinone with glutathione. - Abstract: The electrochemical oxidation of 3,5-di-tert-buthylcatechol in the presence of homocysteine was used for the selective electrochemical determination of homocysteine in the presence of cysteine and glutathione at a glassy carbon and a glassy carbon electrode modified with carbon nanotube. The results revealed that the electrochemically generated 3,5-di-tert-butylcyclohexa-3,5-diene-1,2-dione exhibits high catalytic activity toward homocysteine oxidation at reduced over-potential and low catalytic activity for oxidation of cysteine. The catalytic activity 3,5-di-tert-butylcyclohexa-3,5-diene-1,2-dione toward cysteine was suppressed in the presence of 4-N,N-dimethylaminocinnamaldehyde. Contrary to homocysteine and cysteine, the reaction of glutathione with 3,5-di-tert-butylcyclohexa-3,5-diene-1,2-dione is a substituation reaction. This method exhibits three dynamic linear ranges of 2.5 to 10 μmol L −1 , 10 to 100 μmol L −1 and 100 to 1000 μmol L −1 , and a lower detection limit (3σ) of 0.89 ± 3.53% μmol L −1 for homocysteine

  11. Preparation and characterization of a cysteine based DTPA derivative and its immunoconjugate for radioimmunotherapy

    International Nuclear Information System (INIS)

    Lee, S. Y.; Hong, Y. D.; Choi, S. J.

    2007-01-01

    Recently, radioimmunotherapy (RIT), which uses a monoclonal antibody in addition to a radionuclide to deliver radiation to the sites of a disease, has been extensively studied in this population. To label an antibody with radionuclides it is necessary to introduce a bifunctional chelating agent (BFCA) such a DTPA since it can not be directly labeled to a radionuclide. Therefore, developing a better BFCA for chelating biomolecule and radionuclide has been of major interest in developing radioimmunotherapeutic agents. Thereby, we describe the entantiospecific synthesis of a DTPA analogue which is derived from L-cysteine via bis N-alkylation. And the prepared DTPA derivative was conjugated with human Immunoglobulin G, and a characterization of the immunoconjugate was carried out. N, N-Bis[(tert-butoxycarbonyl)methyl]-2-ethanolamine, N, N-Bis[(tert-butoxycarbony)methyl]-2-bromoethyl-amine, 2-(4-N-Boc-aminophenyl) ethanol, 1-(4-N-Boc-aminophenyl)-2-bromoethane, S-((4-N-Boc-arninophenyl)-1-ethyl)-cysteine methylester, S-(N-Boc-aminophenyl)-Cys(tBu4-DTPA) methylester, -aminophenylethyl-Cys-DTPA, isothiocyanate-cysteine-DTPA, Immunoconjugation with IgG. The optimal molar DTPA derivative to IgG conjugation ratio was 1: 1. At higher amounts of DTPA derivative, amounts of unbounded DTPA derivative increased, and the immunoactivities of immunoconjugates reduced. Gel electrophoresis analysis of the immunoconjugates showed no degradation products or other impurities. This demonstrates the stability of the IgG in DTPA derivative. We established the preparation of an amino acid based DTPA by producing 4-Ethylaniline-DTPA-L-Cysteine. At the same molar this DTPA derivative to IgG, the immunoconjugate has stable molecular structure. In conclusion, 4-Ethylaniline-DTPA-L-Cysteine as a BFCA will show good properties for preparing a specific regional delivery system such as in radiopharmaceuticals, as a radiotracer, and NMR contrasting agents

  12. Solid state radiolysis of sulphur-containing amino acids. Cysteine, cystine and methionine

    International Nuclear Information System (INIS)

    Franco Cataldo; Pietro Ragni; Susana Iglesias-Groth; Arturo Manchado

    2011-01-01

    The sulphur-containing proteinaceous amino acids l-cysteine, l-cystine and l-methionine were irradiated in the solid state to a dose of 3.2 MGy. This dose corresponds to that delivered by radionuclide decay in a timescale of 1.05 x 10 9 years to the organic matter buried at a depth >20 m in comets and asteroids. The purity of the sulphur-containing amino acids was studied by differential scanning calorimetry (DSC) before and after the solid state radiolysis and the preservation of the chirality after the radiolysis was studied by chirooptical methods (optical rotatory dispersion, ORD) and by FT-IR spectroscopy. Although the high radiation dose of 3.2 MGy delivered, all the amino acids studied show a high radiation resistance. The best radiation resistance was offered by l-cysteine. The radiolysis of l-cysteine leads to the formation of l-cystine. The radiation resistance of l-methionine is not at the level of l-cysteine but also l-methionine is able to survive the dose of 3.2 MGy. Furthermore in all cases examined the preservation of chirality after radiolysis was clearly observed by the ORD spectroscopy although a certain level of radioracemization was measured in all cases. The radioracemization is minimal in the case of l-cysteine and is more pronounced in the case of l-methionine. In conclusion, the study shows that the sulphur-containing amino acids can survive for 1.05 x 10 9 years and, after extrapolation of the data, even to the age of the Solar System i.e. to 4.6 x 10 9 years. (author)

  13. Metabolism, excretion, and pharmacokinetics of S-allyl-L-cysteine in rats and dogs.

    Science.gov (United States)

    Amano, Hirotaka; Kazamori, Daichi; Itoh, Kenji; Kodera, Yukihiro

    2015-05-01

    The metabolism, excretion, and pharmacokinetics of S-allyl-l-cysteine (SAC), an active key component of garlic supplements, were examined in rats and dogs. A single dose of SAC was administered orally or i.v. to rats (5 mg/kg) and dogs (2 mg/kg). SAC was well absorbed (bioavailability >90%) and its four metabolites-N-acetyl-S-allyl-l-cysteine (NAc-SAC), N-acetyl-S-allyl-l-cysteine sulfoxide (NAc-SACS), S-allyl-l-cysteine sulfoxide (SACS), and l-γ-glutamyl-S-allyl-l-cysteine-were identified in the plasma and/or urine. Renal clearance values (l/h/kg) of SAC indicated its extensive renal reabsorption, which contributed to the long elimination half-life of SAC, especially in dogs (12 hours). The metabolism of SAC to NAc-SAC, principal metabolite of SAC, was studied in vitro and in vivo. Liver and kidney S9 fractions of rats and dogs catalyzed both N-acetylation of SAC and deacetylation of NAc-SAC. After i.v. administration of NAc-SAC, SAC appeared in the plasma and its concentration declined in parallel with that of NAc-SAC. These results suggest that the rate and extent of the formation of NAc-SAC are determined by the N-acetylation and deacetylation activities of liver and kidney. Also, NAc-SACS was detected in the plasma after i.v. administration of either NAc-SAC or SACS, suggesting that NAc-SACS could be formed via both N-acetylation of SACS and S-oxidation of NAc-SAC. In conclusion, this study demonstrated that the pharmacokinetics of SAC in rats and dogs is characterized by its high oral bioavailability, N-acetylation and S-oxidation metabolism, and extensive renal reabsorption, indicating the critical roles of liver and kidney in the elimination of SAC. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

  14. Optimization of Maillard Reaction in Model System of Glucosamine and Cysteine Using Response Surface Methodology.

    Science.gov (United States)

    Arachchi, Shanika Jeewantha Thewarapperuma; Kim, Ye-Joo; Kim, Dae-Wook; Oh, Sang-Chul; Lee, Yang-Bong

    2017-03-01

    Sulfur-containing amino acids play important roles in good flavor generation in Maillard reaction of non-enzymatic browning, so aqueous model systems of glucosamine and cysteine were studied to investigate the effects of reaction temperature, initial pH, reaction time, and concentration ratio of glucosamine and cysteine. Response surface methodology was applied to optimize the independent reaction parameters of cysteine and glucosamine in Maillard reaction. Box-Behnken factorial design was used with 30 runs of 16 factorial levels, 8 axial levels and 6 central levels. The degree of Maillard reaction was determined by reading absorption at 425 nm in a spectrophotometer and Hunter's L, a, and b values. ΔE was consequently set as the fifth response factor. In the statistical analyses, determination coefficients (R 2 ) for their absorbance, Hunter's L, a, b values, and ΔE were 0.94, 0.79, 0.73, 0.96, and 0.79, respectively, showing that the absorbance and Hunter's b value were good dependent variables for this model system. The optimum processing parameters were determined to yield glucosamine-cysteine Maillard reaction product with higher absorbance and higher colour change. The optimum estimated absorbance was achieved at the condition of initial pH 8.0, 111°C reaction temperature, 2.47 h reaction time, and 1.30 concentration ratio. The optimum condition for colour change measured by Hunter's b value was 2.41 h reaction time, 114°C reaction temperature, initial pH 8.3, and 1.26 concentration ratio. These results can provide the basic information for Maillard reaction of aqueous model system between glucosamine and cysteine.

  15. Prospective study of serum cysteine and cysteinylglycine and cancer of the head and neck, esophagus, and stomach in a cohort of male smokers

    Science.gov (United States)

    Background: The nonessential amino acid cysteine is known to be involved in many antioxidant and anticarcinogenic pathways. Cysteinylglycine is a pro-oxidant metabolite of glutathione and a precursor of cysteine. Objective: To examine the relation between serum cysteine and cysteinylglycine and ris...

  16. Fabrication and characterization of a polycrystalline 3C-SiC piezoresistive micro-pressure sensor

    International Nuclear Information System (INIS)

    Chung, Gwiy-Sang

    2010-01-01

    This paper describes polycrystalline (poly) 3C-SiC piezoresistive micro-pressure sensors for extreme environment applications prepared with a combination crystal growth technology using chemical vapor deposition (CVD) and micromachining techniques. The device was designed using bulk micromachining under a 1 x 1 mm 2 diaphragm and a Si membrane with a thickness of 20 μm. The pressure sensitivities of the fabricated pressure sensors were 0.1 mV/V·bar. The nonlinearity of the devices was ±0.44%·FS, and the hysteresis was 0.61%·FS. The temperature characteristics of the temperature coefficient of sensitivity (TCS), the temperature coefficient of resistance (TCR), and the temperature coefficient of the gauge factor (TCGF) were also evaluated. The TCS of the pressure sensors was -1,867 ppm/ .deg. C, the TCR was -792 ppm/ .deg. C, and the TCGF to 5 bars was -1,042 ppm/ .deg. C, from 25 to 400 .deg. C.

  17. MXene Ti3C2: An Effective 2D Light-to-Heat Conversion Material

    KAUST Repository

    Li, Renyuan

    2017-03-25

    MXene, a new series of 2D material, has been steadily advancing its applications to a variety of fields, such as catalysis, supercapacitor, molecular separation, electromagnetic wave interference shielding. This work reports a carefully designed aqueous droplet light heating system along with a thorough mathematical procedure, which combined leads to a precise determination of internal light-to-heat conversion efficiency of a variety of nanomaterials. The internal light-to-heat conversion efficiency of MXene, more specifically Ti3C2, was measured to be 100%, indicating a perfect energy conversion. Furthermore, a self-floating MXene thin membrane was prepared by simple vacuum filtration and the membrane, in the presence of a rationally chosen heat barrier, produced a light-to-water-evaporation efficiency of 84% under one sun irradiation, which is among the state of art energy efficiency for similar photothermal evaporation system. The outstanding internal light-to-heat conversion efficiency and great light-to-water evaporation efficiency reported in this work suggest that MXene is a very promising light-to-heat conversion material and thus deserves more research attention toward practical applications.

  18. Systems Analysis of an Advanced Nuclear Fuel Cycle Based on a Modified UREX+3c Process

    Energy Technology Data Exchange (ETDEWEB)

    E. R. Johnson; R. E. Best

    2009-12-28

    The research described in this report was performed under a grant from the U.S. Department of Energy (DOE) to describe and compare the merits of two advanced alternative nuclear fuel cycles -- named by this study as the “UREX+3c fuel cycle” and the “Alternative Fuel Cycle” (AFC). Both fuel cycles were assumed to support 100 1,000 MWe light water reactor (LWR) nuclear power plants operating over the period 2020 through 2100, and the fast reactors (FRs) necessary to burn the plutonium and minor actinides generated by the LWRs. Reprocessing in both fuel cycles is assumed to be based on the UREX+3c process reported in earlier work by the DOE. Conceptually, the UREX+3c process provides nearly complete separation of the various components of spent nuclear fuel in order to enable recycle of reusable nuclear materials, and the storage, conversion, transmutation and/or disposal of other recovered components. Output of the process contains substantially all of the plutonium, which is recovered as a 5:1 uranium/plutonium mixture, in order to discourage plutonium diversion. Mixed oxide (MOX) fuel for recycle in LWRs is made using this 5:1 U/Pu mixture plus appropriate makeup uranium. A second process output contains all of the recovered uranium except the uranium in the 5:1 U/Pu mixture. The several other process outputs are various waste streams, including a stream of minor actinides that are stored until they are consumed in future FRs. For this study, the UREX+3c fuel cycle is assumed to recycle only the 5:1 U/Pu mixture to be used in LWR MOX fuel and to use depleted uranium (tails) for the makeup uranium. This fuel cycle is assumed not to use the recovered uranium output stream but to discard it instead. On the other hand, the AFC is assumed to recycle both the 5:1 U/Pu mixture and all of the recovered uranium. In this case, the recovered uranium is reenriched with the level of enrichment being determined by the amount of recovered plutonium and the combined amount

  19. Gas Sloshing and Radio Galaxy Dynamics in the Core of the 3C 449 Group

    Science.gov (United States)

    Lal, Dharam V.; Kraft, Ralph P.; Randall, Scott W.; Forman, William R.; Nulsen, Paul E.; Roediger, Elke; ZuHone, John A.; Hardcastle, Martin J.; Jones, Christine; Croston, Judith H.

    2013-01-01

    We present results from a 140 ks Chandra/ACIS-S observation of the hot gas around the canonical FR I radio galaxy 3C 449. An earlier, shorter 30 ks Chandra observation of the group gas showed an unusual entropy distribution and a surface brightness edge in the gas that could be a strong shock around the inner radio lobes. In our deeper data we find no evidence for a temperature increase inside of the brightness edge, but a temperature decrease across part of the edge. This suggests that the edge is a "sloshing" cold front due to a merger within the last 1.3-1.6 Gyr. Both the northern and southern inner jets are bent slightly to the west in projection as they enter their respective lobes, suggesting that the sloshing core is moving to the east. The straight inner jet flares at approximately the position where it crosses the contact edge, suggesting that the jet is entraining and thermalizing some of the hot gas as it crosses the edge.We also detect filaments of X-ray emission around the southern inner radio jet and lobe which we attribute to low entropy entrained gas. The lobe flaring and gas entrainment were originally predicted in simulations of Loken et al. and are confirmed in our deep observation.

  20. 3C 273 with NuSTAR: Unveiling the Active Galactic Nucleus

    DEFF Research Database (Denmark)

    Madsen, Kristin K.; Fürst, Felix; Walton, Dominic J.

    2015-01-01

    We present results from a 244 ks NuSTAR observation of 3C 273 obtained during a cross-calibration campaign with the Chandra, INTEGRAL, Suzaku, Swift, and XMM-Newton observatories. We show that the spectrum, when fit with a power-law model using data from all observatories except INTEGRAL over the 1......-78 keV band, leaves significant residuals in the NuSTAR data between 30 and 78 keV. The NuSTAR 3-78 keV spectrum is well. described by an exponentially cutoff power law (Γ = 1.646± 0.006, Ecutoff = 202-34 +51 keV) with a weak reflection component from cold, dense material. There is also evidence......-energy power. law is consistent with the presence of a beamed jet, which begins to dominate over emission from the inner accretion flow at 30-40 keV. Modeling the jet locally (in the NuSTAR + INTEGRAL band) as a power. law, we find that the coronal component is fit by ΓAGN = 1.638 ± 0.045, Ecutoff = 47 ± 15 ke...

  1. Radio continuum observations of the quasar-galaxy pair 3C 232-NGC 3067

    International Nuclear Information System (INIS)

    Haxthausen, E.; Carilli, C.; Vangorkom, J.H.

    1990-01-01

    The quasar-galaxy pair 3C 232-NGC 3067 is well known to show absorption by gas associated with the foreground galaxy against the background quasar (see Stocke et al. this volume). Observations by Carilli, van Gorkom, and Stocke (Nature 338, 134, 1989) found that the absorbing gas is located in a long tail of gas which extends from the galaxy toward the quasar and beyond (in projection). Though the HI observations of NGC 3067 indicate that the galaxy has been severely disturbed, there is no obvious candidate in the field which could cause such a disturbance, leading to the conclusion that the system has undergone a recent merger. The radio continuum observations of this system were designed to study the nature of this highly disturbed galaxy. New continuum observations confirm the notion that NGC 3067 is a highly disturbed system, and, in particular, the notion that the western half of the galaxy extends only 1/2 as far in radius as the eastern half. This disturbance must have occurred recently, since the galactic rotation would smooth out the observed asymmetry in about 10(exp 8) years. Researchers are left with the problem that there are no obvious candidates which could have caused such a disturbance

  2. Systems Analysis of an Advanced Nuclear Fuel Cycle Based on a Modified UREX+3c Process

    International Nuclear Information System (INIS)

    Johnson, E.R.; Best, R.E.

    2009-01-01

    The research described in this report was performed under a grant from the U.S. Department of Energy (DOE) to describe and compare the merits of two advanced alternative nuclear fuel cycles -- named by this study as the 'UREX+3c fuel cycle' and the 'Alternative Fuel Cycle' (AFC). Both fuel cycles were assumed to support 100 1,000 MWe light water reactor (LWR) nuclear power plants operating over the period 2020 through 2100, and the fast reactors (FRs) necessary to burn the plutonium and minor actinides generated by the LWRs. Reprocessing in both fuel cycles is assumed to be based on the UREX+3c process reported in earlier work by the DOE. Conceptually, the UREX+3c process provides nearly complete separation of the various components of spent nuclear fuel in order to enable recycle of reusable nuclear materials, and the storage, conversion, transmutation and/or disposal of other recovered components. Output of the process contains substantially all of the plutonium, which is recovered as a 5:1 uranium/plutonium mixture, in order to discourage plutonium diversion. Mixed oxide (MOX) fuel for recycle in LWRs is made using this 5:1 U/Pu mixture plus appropriate makeup uranium. A second process output contains all of the recovered uranium except the uranium in the 5:1 U/Pu mixture. The several other process outputs are various waste streams, including a stream of minor actinides that are stored until they are consumed in future FRs. For this study, the UREX+3c fuel cycle is assumed to recycle only the 5:1 U/Pu mixture to be used in LWR MOX fuel and to use depleted uranium (tails) for the makeup uranium. This fuel cycle is assumed not to use the recovered uranium output stream but to discard it instead. On the other hand, the AFC is assumed to recycle both the 5:1 U/Pu mixture and all of the recovered uranium. In this case, the recovered uranium is reenriched with the level of enrichment being determined by the amount of recovered plutonium and the combined amount of the

  3. Research on numerical control system based on S3C2410 and MCX314AL

    Science.gov (United States)

    Ren, Qiang; Jiang, Tingbiao

    2008-10-01

    With the rapid development of micro-computer technology, embedded system, CNC technology and integrated circuits, numerical control system with powerful functions can be realized by several high-speed CPU chips and RISC (Reduced Instruction Set Computing) chips which have small size and strong stability. In addition, the real-time operating system also makes the attainment of embedded system possible. Developing the NC system based on embedded technology can overcome some shortcomings of common PC-based CNC system, such as the waste of resources, low control precision, low frequency and low integration. This paper discusses a hardware platform of ENC (Embedded Numerical Control) system based on embedded processor chip ARM (Advanced RISC Machines)-S3C2410 and DSP (Digital Signal Processor)-MCX314AL and introduces the process of developing ENC system software. Finally write the MCX314AL's driver under the embedded Linux operating system. The embedded Linux operating system can deal with multitask well moreover satisfy the real-time and reliability of movement control. NC system has the advantages of best using resources and compact system with embedded technology. It provides a wealth of functions and superior performance with a lower cost. It can be sure that ENC is the direction of the future development.

  4. The Solar Flare of the 14th of July 2000 (L3+C detector results)

    CERN Document Server

    Achard, P; Aguilar-Benítez, M; Van den Akker, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Anderhub, H; Andreev, V P; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, G; Baksay, L; Bähr, J; Baldew, S V; Banerjee, S; Banerjee, Sw; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biglietti, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, G J; Böhm, A; Boldizsar, L; Borgia, B; Bottai, S; Bourilkov, D; Bourquin, M; Braccini, S; Branson, J G; Brochu, F; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A; Casaus, J; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Chamizo-Llatas, M; Chiarusi, T; Chang, Y H; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, L; Cindolo, F; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; Dela Cruz, B; Cucciarelli, S; De Asmundis, R; Dglon, P; Debreczeni, J; Degré, A; Dehmelt, K; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Ding, L K; Dionisi, C; Dittmar, M; Doria, A; Dova, M T; Duchesneau, D; Duda, M; Durán, I; Echenard, B; Eline, A; El-Hage, A; El-Mamouni, H; Engler, A; Eppling, F J; Extermann, P; Faber, G; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, M; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, F; Fisher, W; Forconi, G; Freudenreich, K; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gentile, S; Giagu, S; Gong, Z F; Grenier, G; Grabosch, H J; Grimm, O; Groenstege, H; Grünewald, M W; Guida, M; Guo, Y N; Gupta, S K; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Haller, C; Hatzifotiadou, D; Hayashi, Y; He, Z X; Hebbeker, T; Herv, A; Hirschfelder, J; Hofer, H; Hohlmann, M; Holzner, A; Hou, S R; Huo, A X; Ito, N; Jin, B N; Jindal, P; Jing, C L; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kantserov, V A; Kaur, M; Kawakami, S; Kienzle-Focacci, M N; Kim, J K; Kirkby, Jasper; Kittel, W; Klimentov, A; König, A C; Kok, E; Korn, A; Kopal, M; Koutsenko, V F; Kraber, M; Kuang, H H; Krämer, R W; Krüger, A; Kuijpers, J; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Lei, Y; Leich, H; Leiste, R; Levtchenko, M; Levchenko, P M; Li, C; Li, L; Li, Z C; Likhoded, S; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Luci, C; Luminari, L; Lustermann, W; Ma, W G; Ma, X H; Ma, Y Q; Malgeri, L; Malinin, A; Maña, C; Mans, J; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Meng, X W; Merola, L; Meschini, M; Metzger, W J; Mihul, A; Van Mil, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Monteleoni, B; Muanza, G S; Muijs, A J M; Musy, M; Nagy, S; Nahnhauer, R; Naumov, V A; Natale, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nisati, A; Novák, T; Nowak, H; Ofierzynski, R A; Organtini, G; Pal, I; Palomares, C; Paolucci, P; Paramatti, R; Parriaud, J F; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, F; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pieri, M; Pioppi, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Pothier, J; Prokofev, D; Prokofiev, D O; Qing, C R; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Ravindran, K C; Razis, P; Rembeczki, S; Ren, D; Rescigno, M; Reucroft, S; Rewiersma, P A M; Riemann, S; Rojkov, A; Romero, L; Rosca, A; Rosemann, C; Rosenbleck, C; Rosier-Lees, S; Roth, S; Rubio, J A; Ruggiero, G; Rykaczewski, H; Sakharov, A; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Schäfer, C; Shchegelskii, V; Schöneich, B; Schotanus, D J; Sciacca, C; Servoli, L; Shen, C Q; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A; Son, D; Souga, C; Spillantini, P; Steuer, M; Stickland, D P; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S; Suter, H; Swain, J D; Szillási, Z; Tang, X W; Tarjan, P; Tauscher, L; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Trowitzsch, G; Tully, C; Tung, K L; Ulbricht, J; Unger, M; Valente, E; Verkooijen, H; Van de Walle, R T; Vásquez, R; Vesztergombi, G; Vetlitskii, I; Viertel, G; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Wadhwa, M; Wang, G; Wang, Q; Wang, X L; Wang, X W; Wang, Z M; Weber, M; Van Wijk, R; Wijnen, T A M; Wilkens, H; Wynhoff, S; Xia, L; Xu, Y P; Xu, Z Z; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Yang, X F; Yao, Z G; Yeh, S C; Yu, Z Q; Zalite, A; Zalite, Yu; Zhang, C; Zhang, F; Zhang, J; Zhang, S; Zhang, Z P; Zhao, J; Zhou, S J; Zhu, G Y; Zhu, R Y; Zhu, Q Q; Zhuang, H L; Zichichi, A; Zimmermann, B; Zöller, M; Zwart, A N M

    2006-01-01

    Several experiments have reported observations on possible correlations between the flux of high energy muons and intense solar flares. If confirmed, these observations would have significant implications for acceleration processes in the heliosphere able to accelerate protons and other ions to energies of at least tens of GeV. The solar flare of the 14 July 2000 offers a unique opportunity for the L3+C experiment to search for a correlated enhancement in the flux of muons using the L3 precision muon spectrometer. Its capabilities for observing a directional excess in the flux of muons above 15 GeV (corresponding to primary proton energies above 40 GeV) are presented along with observations made on the 14th of July 2000. We report an excess which appeared at a time coincident with the peak increase of solar protons observed at lower energies. The probability that the excess is a background fluctuation is estimated to be 1%. No similar excess of the muon flux was observed up to 1.5 hours after the solar flare ...

  5. ALMA SCIENCE VERIFICATION DATA: MILLIMETER CONTINUUM POLARIMETRY OF THE BRIGHT RADIO QUASAR 3C 286

    Energy Technology Data Exchange (ETDEWEB)

    Nagai, H.; Nakanishi, K.; Hada, K. [National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588 (Japan); Paladino, R. [INAF-Osservatorio di Radioastronomia, Via P. Gobetti, 101 I-40129 Bologna (Italy); Hull, C. L. H. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Cortes, P.; Fomalont, E. [Joint ALMA Observatory, Alonso de Córdova 3107, Vitacura 763 0355, Santiago de Chile (Chile); Moellenbrock, G. [National Radio Astronomy Observatory, Socorro, NM 87801 (United States); Asada, K., E-mail: hiroshi.nagai@nao.ac.jp [The Academia Sinica Institute of Astronomy and Astrophysics, AS/NTU. No.1, Sec. 4, Roosevelt Rd, Taipei 10617, Taiwan, R.O.C (China)

    2016-06-20

    We present full-polarization observations of the compact, steep-spectrum radio quasar 3C 286 made with the Atacama Large Millimeter and Submillimeter Array (ALMA) at 1.3 mm. These are the first full-polarization ALMA observations, which were obtained in the framework of Science Verification. A bright core and a south–west component are detected in the total intensity image, similar to previous centimeter images. Polarized emission is also detected toward both components. The fractional polarization of the core is about 17%; this is higher than the fractional polarization at centimeter wavelengths, suggesting that the magnetic field is even more ordered in the millimeter radio core than it is further downstream in the jet. The observed polarization position angle (or electric vector position angle (EVPA)) in the core is ∼39{sup ◦}, which confirms the trend that the EVPA slowly increases from centimeter to millimeter wavelengths. With the aid of multi-frequency VLBI observations, we argue that this EVPA change is associated with the frequency-dependent core position. We also report a serendipitous detection of a sub-mJy source in the field of view, which is likely to be a submillimeter galaxy.

  6. First- and second-generation total synthesis of ciguatoxin CTX3C.

    Science.gov (United States)

    Inoue, Masayuki; Miyazaki, Keisuke; Uehara, Hisatoshi; Maruyama, Megumi; Hirama, Masahiro

    2004-08-17

    More than 20,000 people suffer annually from ciguatera seafood poisoning in subtropical and tropical regions. The extremely low content of the causative neurotoxins, designated as ciguatoxins, in fish has hampered isolation, detailed biological studies, and preparation of anti-ciguatoxin antibodies for detecting these toxins. Furthermore, the large (3 nm in length) and complex molecular structure of ciguatoxins has impeded chemists from completing their total synthesis. In this article, the full details of studies leading to the total synthesis of ciguatoxin CTX3C are provided. The key elements of the first-generation approach include O,O-acetal formation from the right and left wing fragments, conversion from O,O-acetal to O,S-acetal, a radical reaction to cyclize the G ring, a ring-closing metathesis reaction to close the F ring, and final removal of the 2-naphtylmethyl protective groups. Subsequent studies provided a second-generation total synthesis, which is more concise and results in a higher yield. Second-generation synthesis was accomplished by using a direct method of constructing the key intermediate O,S-acetal from alpha-chlorosulfide and a secondary alcohol. These syntheses ensure a practical supply of ciguatoxin for biological applications.

  7. High temperature energy harvesters utilizing ALN/3C-SiC composite diaphragms

    Science.gov (United States)

    Lai, Yun-Ju; Li, Wei-Chang; Felmetsger, Valery V.; Senesky, Debbie G.; Pisano, Albert P.

    2014-06-01

    Microelectromechanical systems (MEMS) energy harvesting devices aiming at powering wireless sensor systems for structural health monitoring in harsh environments are presented. For harsh environment wireless sensor systems, sensor modules are required to operate at elevated temperatures (> 250°C) with capabilities to resist harsh chemical conditions, thereby the use of battery-based power sources becomes challenging and not economically efficient if considering the required maintenance efforts. To address this issue, energy harvesting technology is proposed to replace batteries and provide a sustainable power source for the sensor systems towards autonomous harsh environment wireless sensor networks. In particular, this work demonstrates a micromachined aluminum nitride/cubic silicon carbide (AlN/3C-SiC) composite diaphragm energy harvester, which enables high temperature energy harvesting from ambient pulsed pressure sources. The fabricated device yields an output power density of 87 μW/cm2 under 1.48-psi pressure pulses at 1 kHz while connected to a 14.6-kΩ load resistor. The effects of pulse profile on output voltage have been studied, showing that the output voltage can be maximized by optimizing the diaphragm resonance frequency based on specific pulse characteristics. In addition, temperature dependence of the diaphragm resonance frequency over the range of 20°C to 600°C has been investigated and the device operation at temperatures as high as 600°C has been verified.

  8. H i Absorption in the Steep-Spectrum Superluminal Quasar 3C 216.

    Science.gov (United States)

    Pihlström; Vermeulen; Taylor; Conway

    1999-11-01

    The search for H i absorption in strong compact steep-spectrum sources is a natural way to probe the neutral gas contents in young radio sources. In turn, this may provide information about the evolution of powerful radio sources. The recently improved capabilities of the Westerbork Synthesis Radio Telescope have made it possible to detect a 0.31% (19 mJy) deep neutral atomic hydrogen absorption line associated with the steep-spectrum superluminal quasar 3C 216. The redshift (z=0.67) of the source shifts the frequency of the 21 cm line down to the ultra-high-frequency (UHF) band (850 MHz). The exact location of the H i-absorbing gas remains to be determined by spectral line VLBI observations at 850 MHz. We cannot exclude that the gas might be extended on galactic scales, but we think it is more likely to be located in the central kiloparsec. Constraints from the lack of X-ray absorption probably rule out obscuration of the core region, and we argue that the most plausible site for the H i absorption is in the jet-cloud interaction observed in this source.

  9. THE 3C COOPERATION MODEL APPLIED TO THE CLASSICAL REQUIREMENT ANALYSIS

    Directory of Open Access Journals (Sweden)

    Vagner Luiz Gava

    2012-08-01

    Full Text Available Aspects related to the users' cooperative work are not considered in the traditional approach of software engineering, since the user is viewed independently of his/her workplace environment or group, with the individual model generalized to the study of collective behavior of all users. This work proposes a process for software requirements to address issues involving cooperative work in information systems that provide distributed coordination in the users' actions and the communication among them occurs indirectly through the data entered while using the software. To achieve this goal, this research uses ergonomics, the 3C cooperation model, awareness and software engineering concepts. Action-research is used as a research methodology applied in three cycles during the development of a corporate workflow system in a technological research company. This article discusses the third cycle, which corresponds to the process that deals with the refinement of the cooperative work requirements with the software in actual use in the workplace, where the inclusion of a computer system changes the users’ workplace, from the face to face interaction to the interaction mediated by the software. The results showed that the highest degree of users' awareness about their activities and other system users contribute to a decrease in their errors and in the inappropriate use of the system

  10. Multifrequency observation of the optically violent variable quasar 3C 446

    International Nuclear Information System (INIS)

    Bregman, J.N.; Glassgold, A.E.; Huggins, P.J.; Kinney, A.L.; Mchardy, I.

    1988-01-01

    Nearly 20 years of optical and radio monitoring data as well as seven multifrequency spectra of the violently variable quasar 3C 446 are reported. The monitoring data suggest a correlation between the radio and optical outbursts, with the optical flare preceding the radio activity by 400-600 days. Considerable processing occurs in the optical-emitting plasma before it becomes radio-emitting plasma. Within the radio band, outbursts proceed from high to low frequencies. The flat radio spectrum turns over at 3-10 x 10 to the 11th Hz and the continuum steepens with frequency. The X-ray emission lies an order of magnitude above an extrapolation of the optical-UV spectrum and has a harder spectrum. The power is primarily concentrated in the submillimeter and infrared region. The data suggest that the X-rays are produced by the inverse Compton process from an emitting region smaller than but related to the synchrotron-emitting UV-IR region. The characteristic size of the emitting region increases with decreasing frequency. 36 references

  11. Isolation of the antibiotic pseudopyronine B and SAR evaluation of C3/C6 alkyl analogs.

    Science.gov (United States)

    Bouthillette, Leah M; Darcey, Catherine A; Handy, Tess E; Seaton, Sarah C; Wolfe, Amanda L

    2017-06-15

    Natural products are an abundant source of structurally diverse compounds with antibacterial activity that can be used to develop new and potent antibiotics. One such class of natural products is the pseudopyronines. Here we present the isolation of pseudopyronine B (2) from a Pseudomonas species found in garden soil in Western North Carolina, and SAR evaluation of C3 and C6 alkyl analogs of the natural product for antibacterial activity against Gram-positive and Gram-negative bacteria. We found a direct relationship between antibacterial activity and C3/C6 alkyl chain length. For inhibition of Gram-positive bacteria, alkyl chain lengths between 6 and 7 carbons were found to be the most active (IC 50 =0.04-3.8µg/mL) whereas short alkyl chain analogs showed modest activity against Gram-negative bacteria (IC 50 =223-304µg/mL). This demonstrates the potential for this class of natural products to be optimized for selective activity against either Gram-positive or Gram-negative bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Kinetic mechanism of V-shaped twinning in 3C/4H-SiC heteroepitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Bin; Zhang, Yu-Ming; Jia, Ren-Xu, E-mail: rxjia@mail.xidian.edu.cn [School of Microelectronics, Xidian University, Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, Xi' an 710071 (China); Wu, Hong-Ming [Graduate Institute of Electronics Engineering, National Taiwan University, 10617 Taipei, Taiwan (China); Feng, Zhe Chuan [Graduate Institute of Photonics and Optoelectronics, National Taiwan University, 10617 Taipei, Taiwan and Laboratory of Optoelectronic Materials and Detection Technology, Guangxi Key Laboratory for the Relativistic Astrophysics, College of Physics Science and Technology, Guangxi University, Nanning 530004 (China); Lin, Hao-Hsiung [Graduate Institute of Electronics Engineering, National Taiwan University, 10617 Taipei, Taiwan and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, 10617 Taipei, Taiwan (China)

    2016-05-15

    The authors investigated the kinetic mechanism of V-shaped twinning in 3C/4H-SiC heteroepitaxy. A fourfold V-shaped twinning complex was found, and its interface was measured with high-resolution transmission electron microscopy (HRTEM). Two linear coherent boundaries and a nonlinear incoherent boundary (also called the double-position boundary) were observed. On the basis of the HRTEM results, the authors proposed an adatom migration growth model, in which the activation barrier at the coherent boundary is much lower than that at the incoherent boundary. From a kinetic perspective, adatoms are prone to migrate to the side of the boundary with the lower potential energy if they have sufficient thermal energy to overcome the activation barrier. In the case of a coherent boundary, the growth rates of the domains either side of the boundary can be balanced through the intermigration of adatoms, leading to a linear boundary. Conversely, it is difficult for adatoms to migrate across an incoherent boundary, which results in asynchronous growth rates and a nonlinear boundary.

  13. Development of M3C code for Monte Carlo reactor physics criticality calculations

    International Nuclear Information System (INIS)

    Kumar, Anek; Kannan, Umasankari; Krishanani, P.D.

    2015-06-01

    The development of Monte Carlo code (M3C) for reactor design entails use of continuous energy nuclear data and Monte Carlo simulations for each of the neutron interaction processes. BARC has started a concentrated effort for developing a new general geometry continuous energy Monte Carlo code for reactor physics calculation indigenously. The code development required a comprehensive understanding of the basic continuous energy cross section sets. The important features of this code are treatment of heterogeneous lattices by general geometry, use of point cross sections along with unionized energy grid approach, thermal scattering model for low energy treatment, capability of handling the microscopic fuel particles dispersed randomly. The capability of handling the randomly dispersed microscopic fuel particles which is very useful for the modeling of High-Temperature Gas-Cooled reactor fuels which are composed of thousands of microscopic fuel particle (TRISO fuel particle), randomly dispersed in a graphite matrix. The Monte Carlo code for criticality calculation is a pioneering effort and has been used to study several types of lattices including cluster geometries. The code has been verified for its accuracy against more than 60 sample problems covering a wide range from simple (like spherical) to complex geometry (like PHWR lattice). Benchmark results show that the code performs quite well for the criticality calculation of the system. In this report, the current status of the code, features of the code, some of the benchmark results for the testing of the code and input preparation etc. are discussed. (author)

  14. Image of the Quasar 3C 273 Taken by the High Energy Astronomy Observatory (HEAO)-2

    Science.gov (United States)

    1979-01-01

    This image is an observation of Quasar 3C 273 by the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory. It reveals the presence of a new source (upper left) with a red shift that indicates that it is about 10 billion light years away. Quasars are mysterious, bright, star-like objects apparently located at the very edge of the visible universe. Although no bigger than our solar system, they radiate as much visible light as a thousand galaxies. Quasars also emit radio signals and were previously recognized as x-ray sources. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2 was designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center.

  15. Ratiometric photoluminescence sensing based on Ti3C2 MXene quantum dots as an intracellular pH sensor.

    Science.gov (United States)

    Chen, Xu; Sun, Xueke; Xu, Wen; Pan, Gencai; Zhou, Donglei; Zhu, Jinyang; Wang, He; Bai, Xue; Dong, Biao; Song, Hongwei

    2018-01-18

    Intracellular pH sensing is of importance and can be used as an indicator for monitoring the evolution of various diseases and the health of cells. Here, we developed a new class of surface-functionalized MXene quantum dots (QDs), Ti 3 C 2 , by the sonication cutting and hydrothermal approach and further explored their intracellular pH sensing. The functionalized Ti 3 C 2 QDs exhibit bright excitation-dependent blue photoluminescence (PL) originating from the size effect and surface defects. Meanwhile, Ti 3 C 2 QDs demonstrate a high PL response induced by the deprotonation of the surface defects. Furthermore, combining the highly pH sensitive Ti 3 C 2 QDs with the pH insensitive [Ru(dpp) 3 ]Cl 2 , we developed a ratiometric pH sensor to quantitatively monitor the intracellular pH values. These novel MXene quantum dots can serve as a promising platform for developing practical fluorescent nanosensors.

  16. Synthesis of pyrano[2,3-c]carbazoles, pyrano[3,2-b]carbazoles and ...

    Indian Academy of Sciences (India)

    2,3-c]carbazoles, pyrano[3,2-b]carbazoles and furo[3,2-b]carbazole derivatives via iodocyclization. KRISHNA CHAITANYA TALLURI and RAJAGOPAL NAGARAJAN. ∗. School of Chemistry, University of Hyderabad, Hyderabad 500046, India.

  17. High-capacity FeTiO3/C negative electrode for sodium-ion batteries with ultralong cycle life

    Science.gov (United States)

    Ding, Changsheng; Nohira, Toshiyuki; Hagiwara, Rika

    2018-06-01

    The development of electrode materials which improve both the energy density and cycle life is one of the most challenging issues facing the practical application of sodium-ion batteries today. In this work, FeTiO3/C nanoparticles are synthesized as negative electrode materials for sodium-ion batteries. The electrochemical performance and charge-discharge mechanism of the FeTiO3/C negative electrode are investigated in an ionic liquid electrolyte at 90 °C. The FeTiO3/C negative electrode delivers a high reversible capacity of 403 mAh g-1 at a current rate of 10 mA g-1, and exhibits high rate capability and excellent cycling stability for up to 2000 cycles. The results indicate that FeTiO3/C is a promising negative electrode material for sodium-ion batteries.

  18. Novel derivative of aminobenzenesulfonamide (3c) induces apoptosis in colorectal cancer cells through ROS generation and inhibits cell migration.

    Science.gov (United States)

    Al-Khayal, Khayal; Alafeefy, Ahmed; Vaali-Mohammed, Mansoor-Ali; Mahmood, Amer; Zubaidi, Ahmed; Al-Obeed, Omar; Khan, Zahid; Abdulla, Maha; Ahmad, Rehan

    2017-01-03

    Colorectal cancer (CRC) is the 3 rd most common type of cancer worldwide. New anti-cancer agents are needed for treating late stage colorectal cancer as most of the deaths occur due to cancer metastasis. A recently developed compound, 3c has shown to have potent antitumor effect; however the mechanism underlying the antitumor effect remains unknown. 3c-induced inhibition of proliferation was measured in the absence and presence NAC using MTT in HT-29 and SW620 cells and xCELLigence RTCA DP instrument. 3c-induced apoptotic studies were performed using flow cytometry. 3c-induced redox alterations were measured by ROS production using fluorescence plate reader and flow cytometry and mitochondrial membrane potential by flow cytometry; NADPH and GSH levels were determined by colorimetric assays. Bcl2 family protein expression and cytochrome c release and PARP activation was done by western blotting. Caspase activation was measured by ELISA. Cell migration assay was done using the real time xCELLigence RTCA DP system in SW620 cells and wound healing assay in HT-29. Many anticancer therapeutics exert their effects by inducing reactive oxygen species (ROS). In this study, we demonstrate that 3c-induced inhibition of cell proliferation is reversed by the antioxidant, N-acetylcysteine, suggesting that 3c acts via increased production of ROS in HT-29 cells. This was confirmed by the direct measurement of ROS in 3c-treated colorectal cancer cells. Additionally, treatment with 3c resulted in decreased NADPH and glutathione levels in HT-29 cells. Further, investigation of the apoptotic pathway showed increased release of cytochrome c resulting in the activation of caspase-9, which in turn activated caspase-3 and -6. 3c also (i) increased p53 and Bax expression, (ii) decreased Bcl2 and BclxL expression and (iii) induced PARP cleavage in human colorectal cancer cells. Confirming our observations, NAC significantly inhibited induction of apoptosis, ROS production, cytochrome c

  19. Ab-initio study of pressure evolution of structural, mechanical and magnetic properties of cementite (Fe3C) phase

    Science.gov (United States)

    Gorai, S.; Ghosh, P. S.; Bhattacharya, C.; Arya, A.

    2018-04-01

    The pressure evolution of phase stability, structural and mechanical properties of Fe3C in ferro-magnetic (FM) and high pressure non magnetic (NM) phase is investigated from first principle calculations. The 2nd order FM to NM phase transition of Fe3C is identified around 60 GPa. Pressure (or density) variation of sound velocities from our ab-initio calculated single crystal elastic constants are determined to predict these parameters at Earth's outer core pressure.

  20. Synthesis of 2',3'-dideoxy-3'-C-(hydroxymethyl)-4'-thiopentofuranosyl nucleosides as potential antiviral agent.

    Science.gov (United States)

    Ichikawa, E; Yamamura, S; Kato, K

    1999-04-19

    1-O-Acetyl-2,3-dideoxy-3-C-(hydroxymethyl)-4-thiofuranose derivative was synthesized from (S,S)-1,4-bis(benzyloxy)-2,3-epoxybutane derived from (+)-diethyl L-tartrate and the enantiomerically pure (E)-5-(2-bromovinyl)-1-[2',3'-dideoxy-3'-C-(hydroxymethyl)-beta-D-4'- thiopentofuranosyl]uracil 4 was obtained via coupling of silylated uracil followed by palladium-mediated coupling of methyl acrylate.

  1. Epstein-Barr virus nuclear antigen 3C targets p53 and modulates its transcriptional and apoptotic activities

    International Nuclear Information System (INIS)

    Yi Fuming; Saha, Abhik; Murakami, Masanao; Kumar, Pankaj; Knight, Jason S.; Cai Qiliang; Choudhuri, Tathagata; Robertson, Erle S.

    2009-01-01

    The p53 tumor suppressor gene is one of the most commonly mutated genes in human cancers and the corresponding encoded protein induces apoptosis or cell-cycle arrest at the G1/S checkpoint in response to DNA damage. To date, previous studies have shown that antigens encoded by human tumor viruses such as SV40 large T antigen, adenovirus E1A and HPV E6 interact with p53 and disrupt its functional activity. In a similar fashion, we now show that EBNA3C, one of the EBV latent antigens essential for the B-cell immortalization in vitro, interacts directly with p53. Additionally, we mapped the interaction of EBNA3C with p53 to the C-terminal DNA-binding and the tetramerization domain of p53, and the region of EBNA3C responsible for binding to p53 was mapped to the N-terminal domain of EBNA3C (residues 130-190), previously shown to interact with a number of important cell-cycle components, specifically SCF Skp2 , cyclin A, and cMyc. Furthermore, we demonstrate that EBNA3C substantially represses the transcriptional activity of p53 in luciferase based reporter assays, and rescues apoptosis induced by ectopic p53 expression in SAOS-2 (p53 -/- ) cells. Interestingly, we also show that the DNA-binding ability of p53 is diminished in the presence of EBNA3C. Thus, the interaction between the p53 and EBNA3C provides new insights into the mechanism(s) by which the EBNA3C oncoprotein can alter cellular gene expression in EBV associated human cancers.

  2. A novel electrochemical sensor based on metal-organic framework for electro-catalytic oxidation of L-cysteine.

    Science.gov (United States)

    Hosseini, Hadi; Ahmar, Hamid; Dehghani, Ali; Bagheri, Akbar; Tadjarodi, Azadeh; Fakhari, Ali Reza

    2013-04-15

    A novel electrochemical sensor based on Au-SH-SiO₂ nanoparticles supported on metal-organic framework (Au-SH-SiO₂@Cu-MOF) has been developed for electrocatalytic oxidation and determination of L-cysteine. The Au-SH-SiO₂@Cu-MOF was characterized by scanning electron microscopy, transmission electron microscopy, x-ray diffraction and cyclic voltammetry. The electrochemical behavior of L-cysteine at the Au-SH-SiO₂@Cu-MOF was investigated by cyclic voltammetry. The Au-SH-SiO₂@Cu-MOF showed a very efficient electrocatalytic activity for the oxidation of L-cysteine in 0.1 M phosphate buffer solution (pH 5.0). The oxidation overpotentials of L-cysteine decreased significantly and their oxidation peak currents increased dramatically at Au-SH-SiO₂@Cu-MOF. The potential utility of the sensor was demonstrated by applying it to the analytical determination of L-cysteine concentration. The results showed that the electrocatalytic current increased linearly with the L-cysteine concentration in the range of 0.02-300 μM and the detection limit was 0.008 μM. Finally, the sensor was applied to determine L-cysteine in water and biological samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Detection of l-Cysteine in wheat flour by Raman microspectroscopy combined chemometrics of HCA and PCA.

    Science.gov (United States)

    Cebi, Nur; Dogan, Canan Ekinci; Develioglu, Ayşen; Yayla, Mediha Esra Altuntop; Sagdic, Osman

    2017-08-01

    l-Cysteine is deliberately added to various flour types since l-Cysteine has enabled favorable baking conditions such as low viscosity, increased elasticity and rise during baking. In Turkey, usage of l-Cysteine as a food additive isn't allowed in wheat flour according to the Turkish Food Codex Regulation on food additives. There is an urgent need for effective methods to detect l-Cysteine in wheat flour. In this study, for the first time, a new, rapid, effective, non-destructive and cost-effective method was developed for detection of l-Cysteine in wheat flour using Raman microscopy. Detection of l-Cysteine in wheat flour was accomplished successfully using Raman microscopy combined chemometrics of PCA (Principal Component Analysis) and HCA (Hierarchical Cluster Analysis). In this work, 500-2000cm -1 spectral range (fingerprint region) was determined to perform PCA and HCA analysis. l-Cysteine and l-Cystine were determined with detection limit of 0.125% (w/w) in different wheat flour samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Surface modified MXene Ti3C2 multilayers by aryl diazonium salts leading to large-scale delamination

    Science.gov (United States)

    Wang, Hongbing; Zhang, Jianfeng; Wu, Yuping; Huang, Huajie; Li, Gaiye; Zhang, Xin; Wang, Zhuyin

    2016-10-01

    Herein we report a simple and facile method to delaminate MXene Ti3C2 multilayers by the assistance of surface modification using aryl diazonium salts. The basic strategy involved the preparation of layered MAX Ti3AlC2 and the exfoliation of Ti3AlC2 into Ti3C2 multilayers, followed by Na+ intercalation and surface modification using sulfanilic acid diazonium salts. The resulting chemically grafted Ti3C2 flakes were characterized by Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) to confirm the presence of the surface organic species. Ultraviolet-visible spectroscopy revealed that surface-modified MXene Ti3C2 sheets disperse well in water and the solutions obey Lambert-Beer's law. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to demonstrate the morphology and structure of delaminating MXene Ti3C2 flakes. The results indicated that chemical modification for MXene multilayers by aryl diazonium salts induced swelling that conversely weakened the bonds between MX layers, hence leading to large-scale delamination of multilayered MXene Ti3C2via mild sonication. Advantages of the present approach rely not only on the simplicity and efficiency of the delamination procedure but also on the grafting of aryl groups to MXene surfaces, highly suitable for further applications of the newly discovered two-dimensional materials.

  5. Feline infectious peritonitis: insights into feline coronavirus pathobiogenesis and epidemiology based on genetic analysis of the viral 3c gene.

    Science.gov (United States)

    Chang, Hui-Wen; de Groot, Raoul J; Egberink, Herman F; Rottier, Peter J M

    2010-02-01

    Feline infectious peritonitis (FIP) is a lethal systemic disease caused by FIP virus (FIPV), a virulent mutant of apathogenic feline enteric coronavirus (FECV). We analysed the 3c gene--a proposed virulence marker--in 27 FECV- and 28 FIPV-infected cats. Our findings suggest that functional 3c protein expression is crucial for FECV replication in the gut, but dispensable for systemic FIPV replication. Whilst intact in all FECVs, the 3c gene was mutated in the majority (71.4 %) of FIPVs, but not in all, implying that mutation in 3c is not the (single) cause of FIP. Most cats with FIP had no detectable intestinal feline coronaviruses (FCoVs) and had seemingly cleared the primary FECV infection. In those with detectable intestinal FCoV, the virus always had an intact 3c and seemed to have been acquired by FECV superinfection. Apparently, 3c-inactivated viruses replicate not at all--or only poorly--in the gut, explaining the rare incidence of FIP outbreaks.

  6. The effect of pre-dose on thermally and optically stimulated luminescence from α-Al2O3:C,Mg and α-Al2O3:C.

    Science.gov (United States)

    Kalita, J M; Chithambo, M L

    2018-06-15

    We report the effect of pre-dose on the thermoluminescence (TL) and optically stimulated luminescence (OSL) dose response of α-Al 2 O 3 :C,Mg and α-Al 2 O 3 :C. Before any luminescence measurement, the samples were irradiated with different doses, namely 100, 500 and 1000 Gy to populate the deep electron traps. This is the pre-dose. The results from TL and OSL studies are compared with results from samples used without any pre-measurement dose. The TL glow curves and OSL decay curves of α-Al 2 O 3 :C,Mg recorded after pre-doses of 100, 500 and 1000 Gy are identical to those from a sample used without any pre-dose. Further, the TL and OSL dose response of all α-Al 2 O 3 :C,Mg samples are similar regardless of pre-dose. In comparison, the TL glow curves and OSL decay curves of α-Al 2 O 3 :C are influenced by pre-dose. We conclude that the differences in the TL and OSL dose response of various pre-dosed samples of α-Al 2 O 3 :C are due to the concentration of charge in the deep traps. On the other hand, owing to the lower concentration of such deep traps in α-Al 2 O 3 :C,Mg, the TL or OSL dose responses are not affected by pre-dose in this material. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Cysteine reversal of the novel neuromuscular blocking drug CW002 in dogs: pharmacodynamics, acute cardiovascular effects, and preliminary toxicology.

    Science.gov (United States)

    Sunaga, Hiroshi; Malhotra, Jaideep K; Yoon, Edward; Savarese, John J; Heerdt, Paul M

    2010-04-01

    CW002 is a neuromuscular blocking drug that is inactivated by endogenous L-cysteine. This study determined the exogenous L-cysteine dose-response relationship for CW002 reversal along with acute cardiovascular effects and organ toxicity in dogs. Six dogs were each studied four times during isoflurane-nitrous oxide anesthesia and recording of muscle twitch, arterial pressure, and heart rate. CW002 (0.08 mg/kg or 9 x ED95) was injected, and the time to spontaneous muscle recovery was determined. CW002 was then administered again followed 1 min later by 10, 20, 50, or 100 mg/kg L-cysteine (1 dose/experiment). After twitch recovery, CW002 was given a third time to determine whether residual L-cysteine influenced duration. Preliminary toxicology was performed in an additional group of dogs that received CW002 followed by vehicle (n = 8) or 200 mg/kg L-cysteine (n = 8). Animals were awakened and observed for 2 or 14 days before sacrificing and anatomic, biochemical, and histopathologic analyses. L-cysteine at all doses accelerated recovery from CW002, with both 50 and 100 mg/kg decreasing median duration from more than 70 min to less than 5 min. After reversal, duration of a subsequent CW002 dose was also decreased in a dose-dependent manner. Over the studied dose range, L-cysteine had less than 10% effect on blood pressure and heart rate. Animals receiving a single 200-mg/kg dose of L-cysteine showed no clinical, anatomic, biochemical, or histologic evidence of organ toxicity. The optimal L-cysteine dose for rapidly reversing the neuromuscular blockade produced by a large dose of CW002 in dogs is approximately 50 mg/kg, which has no concomitant hemodynamic effect. A dose of 200 mg/kg had no evident organ toxicity.

  8. Global analysis of gene expression in response to L-Cysteine deprivation in the anaerobic protozoan parasite Entamoeba histolytica

    Science.gov (United States)

    2011-01-01

    Background Entamoeba histolytica, an enteric protozoan parasite, causes amebic colitis and extra intestinal abscesses in millions of inhabitants of endemic areas. E. histolytica completely lacks glutathione metabolism but possesses L-cysteine as the principle low molecular weight thiol. L-Cysteine is essential for the structure, stability, and various protein functions, including catalysis, electron transfer, redox regulation, nitrogen fixation, and sensing for regulatory processes. Recently, we demonstrated that in E. histolytica, L-cysteine regulates various metabolic pathways including energy, amino acid, and phospholipid metabolism. Results In this study, employing custom-made Affymetrix microarrays, we performed time course (3, 6, 12, 24, and 48 h) gene expression analysis upon L-cysteine deprivation. We identified that out of 9,327 genes represented on the array, 290 genes encoding proteins with functions in metabolism, signalling, DNA/RNA regulation, electron transport, stress response, membrane transport, vesicular trafficking/secretion, and cytoskeleton were differentially expressed (≥3 fold) at one or more time points upon L-cysteine deprivation. Approximately 60% of these modulated genes encoded proteins of no known function and annotated as hypothetical proteins. We also attempted further functional analysis of some of the most highly modulated genes by L-cysteine depletion. Conclusions To our surprise, L-cysteine depletion caused only limited changes in the expression of genes involved in sulfur-containing amino acid metabolism and oxidative stress defense. In contrast, we observed significant changes in the expression of several genes encoding iron sulfur flavoproteins, a major facilitator super-family transporter, regulator of nonsense transcripts, NADPH-dependent oxido-reductase, short chain dehydrogenase, acetyltransferases, and various other genes involved in diverse cellular functions. This study represents the first genome-wide analysis of

  9. Global analysis of gene expression in response to L-Cysteine deprivation in the anaerobic protozoan parasite Entamoeba histolytica

    Directory of Open Access Journals (Sweden)

    Jeelani Ghulam

    2011-05-01

    Full Text Available Abstract Background Entamoeba histolytica, an enteric protozoan parasite, causes amebic colitis and extra intestinal abscesses in millions of inhabitants of endemic areas. E. histolytica completely lacks glutathione metabolism but possesses L-cysteine as the principle low molecular weight thiol. L-Cysteine is essential for the structure, stability, and various protein functions, including catalysis, electron transfer, redox regulation, nitrogen fixation, and sensing for regulatory processes. Recently, we demonstrated that in E. histolytica, L-cysteine regulates various metabolic pathways including energy, amino acid, and phospholipid metabolism. Results In this study, employing custom-made Affymetrix microarrays, we performed time course (3, 6, 12, 24, and 48 h gene expression analysis upon L-cysteine deprivation. We identified that out of 9,327 genes represented on the array, 290 genes encoding proteins with functions in metabolism, signalling, DNA/RNA regulation, electron transport, stress response, membrane transport, vesicular trafficking/secretion, and cytoskeleton were differentially expressed (≥3 fold at one or more time points upon L-cysteine deprivation. Approximately 60% of these modulated genes encoded proteins of no known function and annotated as hypothetical proteins. We also attempted further functional analysis of some of the most highly modulated genes by L-cysteine depletion. Conclusions To our surprise, L-cysteine depletion caused only limited changes in the expression of genes involved in sulfur-containing amino acid metabolism and oxidative stress defense. In contrast, we observed significant changes in the expression of several genes encoding iron sulfur flavoproteins, a major facilitator super-family transporter, regulator of nonsense transcripts, NADPH-dependent oxido-reductase, short chain dehydrogenase, acetyltransferases, and various other genes involved in diverse cellular functions. This study represents the first

  10. Broad-Spectrum Inhibitors against 3C-Like Proteases of Feline Coronaviruses and Feline Caliciviruses

    Science.gov (United States)

    Shivanna, Vinay; Narayanan, Sanjeev; Prior, Allan M.; Weerasekara, Sahani; Hua, Duy H.; Kankanamalage, Anushka C. Galasiti; Groutas, William C.; Chang, Kyeong-Ok

    2015-01-01

    ABSTRACT Feline infectious peritonitis and virulent, systemic calicivirus infection are caused by certain types of feline coronaviruses (FCoVs) and feline caliciviruses (FCVs), respectively, and are important infectious diseases with high fatality rates in members of the Felidae family. While FCoV and FCV belong to two distinct virus families, the Coronaviridae and the Caliciviridae, respectively, they share a dependence on viral 3C-like protease (3CLpro) for their replication. Since 3CLpro is functionally and structurally conserved among these viruses and essential for viral replication, 3CLpro is considered a potential target for the design of antiviral drugs with broad-spectrum activities against these distinct and highly important viral infections. However, small-molecule inhibitors against the 3CLpro enzymes of FCoV and FCV have not been previously identified. In this study, derivatives of peptidyl compounds targeting 3CLpro were synthesized and evaluated for their activities against FCoV and FCV. The structures of compounds that showed potent dual antiviral activities with a wide margin of safety were identified and are discussed. Furthermore, the in vivo efficacy of 3CLpro inhibitors was evaluated using a mouse model of coronavirus infection. Intraperitoneal administration of two 3CLpro inhibitors in mice infected with murine hepatitis virus A59, a hepatotropic coronavirus, resulted in significant reductions in virus titers and pathological lesions in the liver compared to the findings for the controls. These results suggest that the series of 3CLpro inhibitors described here may have the potential to be further developed as therapeutic agents against these important viruses in domestic and wild cats. This study provides important insights into the structure and function relationships of 3CLpro for the design of antiviral drugs with broader antiviral activities. IMPORTANCE Feline infectious peritonitis virus (FIPV) is the leading cause of death in young cats

  11. IS GNB3 C825T POLYMORPHISM ASSOCIATED WITH ELITE STATUS OF POLISH ATHLETES?

    Directory of Open Access Journals (Sweden)

    M. Sawczuk

    2014-07-01

    Full Text Available The GNB3 gene encodes the beta 3 subunit of heterotrimeric G-proteins that are key components of intracellular signal transduction between G protein-coupled receptors (GPCR and intracellular effectors and might be considered as a potential candidate gene for physical performance. Objectives: The aim of this study was to compare frequency distribution of the common C to T polymorphism at position 825 (C825T of the GNB3 gene between athletes and nonathletic controls of the Polish population as well as to compare the genotype distribution and allele frequency of C825T variants within a group of athletes, i.e. between athletes of sports of different metabolic demands and competitive levels. Methods: The study was performed in a group of 223 Polish athletes of the highest nationally competitive standard (123 endurance-oriented athletes and 100 strength/power athletes. Control samples were prepared from 354 unrelated, sedentary volunteers. Results: The χ2 test revealed no statistical differences between the endurance-oriented athletes and the control group or between sprint/strength athletes and the control group across the GNB3 825C/T genotypes. There were no male-female genotype or allele frequency differences in controls or in either strength/power or endurance-oriented athletes. No statistically significant differences in either allele frequencies or genotype distribution were noted between the top-elite, elite or sub-elite of endurance-oriented and strength/power athletes and the control group. Conclusions: No association between elite status of Polish athletes and the GNB3 C825T polymorphic site has been found.

  12. Cleavage of sp3 C-O bonds via oxidative addition of C-H bonds.

    Science.gov (United States)

    Choi, Jongwook; Choliy, Yuriy; Zhang, Xiawei; Emge, Thomas J; Krogh-Jespersen, Karsten; Goldman, Alan S

    2009-11-04

    (PCP)Ir (PCP = kappa(3)-C(6)H(3)-2,6-[CH(2)P(t-Bu)(2)](2)) is found to undergo oxidative addition of the methyl-oxygen bond of electron-poor methyl aryl ethers, including methoxy-3,5-bis(trifluoromethyl)benzene and methoxypentafluorobenzene, to give the corresponding aryloxide complexes (PCP)Ir(CH(3))(OAr). Although the net reaction is insertion of the Ir center into the C-O bond, density functional theory (DFT) calculations and a significant kinetic isotope effect [k(CH(3))(OAr)/k(CD(3))(OAr) = 4.3(3)] strongly argue against a simple insertion mechanism and in favor of a pathway involving C-H addition and alpha-migration of the OAr group to give a methylene complex followed by hydride-to-methylene migration to give the observed product. Ethoxy aryl ethers, including ethoxybenzene, also undergo C-O bond cleavage by (PCP)Ir, but the net reaction in this case is 1,2-elimination of ArO-H to give (PCP)Ir(H)(OAr) and ethylene. DFT calculations point to a low-barrier pathway for this reaction that proceeds through C-H addition of the ethoxy methyl group followed by beta-aryl oxide elimination and loss of ethylene. Thus, both of these distinct C-O cleavage reactions proceed via initial addition of a C(sp(3))-H bond, despite the fact that such bonds are typically considered inert and are much stronger than C-O bonds.

  13. Campath, calcineurin inhibitor reduction and chronic allograft nephropathy (3C) study: background, rationale, and study protocol

    Science.gov (United States)

    2013-01-01

    Background Kidney transplantation is the best treatment for patients with end-stage renal failure, but uncertainty remains about the best immunosuppression strategy. Long-term graft survival has not improved substantially, and one possible explanation is calcineurin inhibitor (CNI) nephrotoxicity. CNI exposure could be minimized by using more potent induction therapy or alternative maintenance therapy to remove CNIs completely. However, the safety and efficacy of such strategies are unknown. Methods/Design The Campath, Calcineurin inhibitor reduction and Chronic allograft nephropathy (3C) Study is a multicentre, open-label, randomized controlled trial with 852 participants which is addressing two important questions in kidney transplantation. The first question is whether a Campath (alemtuzumab)-based induction therapy strategy is superior to basiliximab-based therapy, and the second is whether, from 6 months after transplantation, a sirolimus-based maintenance therapy strategy is superior to tacrolimus-based therapy. Recruitment is complete, and follow-up will continue for around 5 years post-transplant. The primary endpoint for the induction therapy comparison is biopsy-proven acute rejection by 6 months, and the primary endpoint for the maintenance therapy comparison is change in estimated glomerular filtration rate from baseline to 2 years after transplantation. The study is sponsored by the University of Oxford and endorsed by the British Transplantation Society, and 18 centers for adult kidney transplant are participating. Discussion Late graft failure is a major issue for kidney-transplant recipients. If our hypothesis that minimizing CNI exposure with Campath-based induction therapy and/or an elective conversion to sirolimus-based maintenance therapy can improve long-term graft function and survival is correct, then patients should experience better graft function for longer. A positive outcome could change clinical practice in kidney transplantation. Trial

  14. Multiwavelength Variations of 3C 454.3 during the 2010 November to 2011 January Outburst

    Science.gov (United States)

    Wehrle, Ann E.; Marscher, Alan P.; Jorstad, Svetlana G.; Gurwell, Mark A.; Joshi, Manasvita; MacDonald, Nicholas R.; Williamson, Karen E.; Agudo, Iván; Grupe, Dirk

    2012-10-01

    We present multiwavelength data of the blazar 3C 454.3 obtained during an extremely bright outburst from 2010 November through 2011 January. These include flux density measurements with the Herschel Space Observatory at five submillimeter-wave and far-infrared bands, the Fermi Large Area Telescope at γ-ray energies, Swift at X-ray, ultraviolet (UV), and optical frequencies, and the Submillimeter Array at 1.3 mm. From this data set, we form a series of 52 spectral energy distributions (SEDs) spanning nearly two months that are unprecedented in time coverage and breadth of frequency. Discrete correlation analysis of the millimeter, far-infrared, and γ-ray light curves show that the variations were essentially simultaneous, indicative of cospatiality of the emission, at these wavebands. In contrast, differences in short-term fluctuations at various wavelengths imply the presence of inhomogeneities in physical conditions across the source. We locate the site of the outburst in the parsec-scale "core," whose flux density as measured on 7 mm Very Long Baseline Array images increased by 70% during the first five weeks of the outburst. Based on these considerations and guided by the SEDs, we propose a model in which turbulent plasma crosses a conical standing shock in the parsec-scale region of the jet. Here, the high-energy emission in the model is produced by inverse Compton scattering of seed photons supplied by either nonthermal radiation from a Mach disk, thermal emission from hot dust, or (for X-rays) synchrotron radiation from plasma that crosses the standing shock. For the two dates on which we fitted the model SED to the data, the model corresponds very well to the observations at all bands except at X-ray energies, where the spectrum is flatter than observed.

  15. MULTIWAVELENGTH VARIATIONS OF 3C 454.3 DURING THE 2010 NOVEMBER TO 2011 JANUARY OUTBURST

    International Nuclear Information System (INIS)

    Wehrle, Ann E.; Marscher, Alan P.; Jorstad, Svetlana G.; Joshi, Manasvita; MacDonald, Nicholas R.; Williamson, Karen E.; Agudo, Iván; Gurwell, Mark A.; Grupe, Dirk

    2012-01-01

    We present multiwavelength data of the blazar 3C 454.3 obtained during an extremely bright outburst from 2010 November through 2011 January. These include flux density measurements with the Herschel Space Observatory at five submillimeter-wave and far-infrared bands, the Fermi Large Area Telescope at γ-ray energies, Swift at X-ray, ultraviolet (UV), and optical frequencies, and the Submillimeter Array at 1.3 mm. From this data set, we form a series of 52 spectral energy distributions (SEDs) spanning nearly two months that are unprecedented in time coverage and breadth of frequency. Discrete correlation analysis of the millimeter, far-infrared, and γ-ray light curves show that the variations were essentially simultaneous, indicative of cospatiality of the emission, at these wavebands. In contrast, differences in short-term fluctuations at various wavelengths imply the presence of inhomogeneities in physical conditions across the source. We locate the site of the outburst in the parsec-scale 'core', whose flux density as measured on 7 mm Very Long Baseline Array images increased by 70% during the first five weeks of the outburst. Based on these considerations and guided by the SEDs, we propose a model in which turbulent plasma crosses a conical standing shock in the parsec-scale region of the jet. Here, the high-energy emission in the model is produced by inverse Compton scattering of seed photons supplied by either nonthermal radiation from a Mach disk, thermal emission from hot dust, or (for X-rays) synchrotron radiation from plasma that crosses the standing shock. For the two dates on which we fitted the model SED to the data, the model corresponds very well to the observations at all bands except at X-ray energies, where the spectrum is flatter than observed.

  16. Exploring the Connection between Parsec-scale Jet Activity and Broadband Outbursts in 3C 279

    Science.gov (United States)

    Rani, B.; Jorstad, S. G.; Marscher, A. P.; Agudo, I.; Sokolovsky, K. V.; Larionov, V. M.; Smith, P.; Mosunova, D. A.; Borman, G. A.; Grishina, T. S.; Kopatskaya, E. N.; Mokrushina, A. A.; Morozova, D. A.; Savchenko, S. S.; Troitskaya, Yu. V.; Troitsky, I. S.; Thum, C.; Molina, S. N.; Casadio, C.

    2018-05-01

    We use a combination of high-resolution very long baseline interferometry (VLBI) radio and multiwavelength flux density and polarization observations to constrain the physics of the dissipation mechanism powering the broadband flares in 3C 279 during an episode of extreme flaring activity in 2013–2014. Six bright flares superimposed on a long-term outburst are detected at γ-ray energies. Four of the flares have optical and radio counterparts. The two modes of flaring activity (faster flares sitting on top of a long-term outburst) present at radio, optical, and γ-ray frequencies are missing in X-rays. X-ray counterparts are only observed for two flares. The first three flares are accompanied by ejection of a new VLBI component (NC2), suggesting the 43 GHz VLBI core as the site of energy dissipation. Another new component, NC3, is ejected after the last three flares, which suggests that the emission is produced upstream from the core (closer to the black hole). The study therefore indicates multiple sites of energy dissipation in the source. An anticorrelation is detected between the optical percentage polarization (PP) and optical/γ-ray flux variations, while the PP has a positive correlation with optical/γ-ray spectral indices. Given that the mean polarization is inversely proportional to the number of cells in the emission region, the PP versus optical/γ-ray anticorrelation could be due to more active cells during the outburst than at other times. In addition to the turbulent component, our analysis suggests the presence of a combined turbulent and ordered magnetic field, with the ordered component transverse to the jet axis.

  17. Transportable nuclear power plant T3C-M with two reactor plants of improved safety

    International Nuclear Information System (INIS)

    Ogloblin, B.G.; Gromov, B.F.

    1993-01-01

    Development and cultivating of districts in Siberia, North, Far East, Kamchatka and other remote or almost inaccessible district of the country depends to a large degree on their providing with power. The specific character of these districts imposes in turn a wide variety of special requirements upon the power sources. In particular, it is essential to provide the following; maximum manufacture availability of the whole equipment at the minimum volume of construction and installation work on operation site, high safety, longterm service life, ecologically, minimum scope of work on equipment in-service maintenance and inspection, etc. Taking into account the well-known difficulties connected with the delivery of conventional energy carriers to the above-mentioned districts and the situation with the alternative power sources, the application of the low-power nuclear plants (NPP) for these purposes looks definitely promising. Among the probable trends in creating the NPPs of this type as very promising is considered the possibility to apply the two-circuit reactor plant of the vessel type with the liquid lead as a primary coolant and free air as a secondary coolant and working medium in the open gas-turbine cycle. The nuclear plant T3C-M of improved safety with two of this type reactor plants with total electric power of 8 MW is developed by CDB of Machine Building with participation of several enterprises of St. Petersburg under the scientific leadership and is intended for generation of electric power and up to 4 Gcal/h of heat for populated areas and installations placed at long distance from the main electric power supply sources where it is difficult or non-efficient economically to deliver the conventional kinds of fuel. The main principles being laid as a basis when developing the proposed NPP will allow one to create mobile power sources which possess a high degree of safety and inherent self-protection

  18. ON THE SOURCE OF FARADAY ROTATION IN THE JET OF THE RADIO GALAXY 3C 120

    International Nuclear Information System (INIS)

    Gomez, Jose L.; Roca-Sogorb, Mar; Agudo, Ivan; Marscher, Alan P.; Jorstad, Svetlana G.

    2011-01-01

    The source of Faraday rotation in the jet of the radio galaxy 3C 120 is analyzed through Very Long Baseline Array observations carried out between 1999 and 2007 at 86, 43, 22, 15, 12, 8, 5, 2, and 1.7 GHz. Comparison of observations from 1999 to 2001 reveals uncorrelated changes in the linear polarization of the underlying jet emission and the Faraday rotation screen: while the rotation measure (RM) remains constant between approximately 2 and 5 mas from the core, the RM-corrected electric vector position angles (EVPAs) of two superluminal components are rotated by almost 90 0 when compared to other components moving through similar jet locations. On the other hand, the innermost 2 mas experiences a significant change in RM-including a sign reversal-but without variations in the RM-corrected EVPAs. Similarly, observations in 2007 reveal a double sign reversal in RM along the jet, while the RM-corrected EVPAs remain perpendicular to the jet axis. Although the observed coherent structure and gradient of the RM along the jet support the idea that the Faraday rotation is produced by a sheath of thermal electrons that surrounds the emitting jet, the uncorrelated changes in the RM and RM-corrected EVPAs indicate that the emitting jet and the source of Faraday rotation are not closely connected physically and have different configurations for the magnetic field and/or kinematical properties. Furthermore, the existence of a region of enhanced RM whose properties remain constant over three years requires a localized source of Faraday rotation, favoring a model in which a significant fraction of the RM originates in foreground clouds.

  19. Early Fermi Gamma-ray Space Telescope Observations of the Quasar 3C454.3

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, A

    2009-05-07

    This is the first report of Fermi Gamma-ray Space Telescope observations of the quasar 3C 454.3, which has been undergoing pronounced long-term outbursts since 2000. The data from the Large Area Telescope (LAT), covering 2008 July 7-October 6, indicate strong, highly variable {gamma}-ray emission with an average flux of {approx} 3 x 10{sup -6} photons cm{sup -2} s{sup -1}, for energies > 100 MeV. The {gamma}-ray flux is variable, with strong, distinct, symmetrically-shaped flares for which the flux increases by a factor of several on a time scale of about three days. This variability indicates a compact emission region, and the requirement that the source is optically thin to pair-production implies relativistic beaming with Doppler factor {delta} > 8, consistent with the values inferred from VLBI observations of superluminal expansion ({delta} {approx} 25). The observed {gamma}-ray spectrum is not consistent with a simple power-law, but instead steepens strongly above {approx} 2 GeV, and is well described by a broken power-law with photon indices of {approx} 2.3 and {approx} 3.5 below and above the break, respectively. This is the first direct observation of a break in the spectrum of a high luminosity blazar above 100 MeV, and it is likely direct evidence for an intrinsic break in the energy distribution of the radiating particles. Alternatively, the spectral softening above 2GeV could be due to -ray absorption via photonphoton pair production on the soft X-ray photon field of the host AGN, but such an interpretation would require the dissipation region to be located very close ({approx}< 100 gravitational radii) to the black hole, which would be inconsistent with the X-ray spectrum of the source.

  20. Determination of stability constants of iron(III and chromium(III-nitrilotriacetate-methyl cysteine mixed complexes by electrophoretic technique

    Directory of Open Access Journals (Sweden)

    Brij Bhushan Tewari

    2004-06-01

    Full Text Available The stability constants of Fe(III and Cr(III with methyl cysteine and nitrilotriacetate (NTA were determined by paper electrophoretic technique. Beside binary ternary complexes have also been studied, in which nitrilotriacetate and methyl cysteine acts as primary and secondary ligand, respectively. The stability constants of mixed ligand complexes metal (M-nitrilotriacetate-methyl cysteine have been found to be 5.72 plus or minus 0.09 and 5.54 plus or minus 0.11 (log K values for Fe(III and Cr(III complexes, respectively, at 35 oC and ionic strength 0.1 M.